Upgrading server dependancies (#8154)

vendor/github.com/prometheus/client_golang/.gitignore

@@ -7,6 +7,10 @@
 _obj
 _test
 
+# Examples
+/examples/simple/simple
+/examples/random/random
+
 # Architecture specific extensions/prefixes
 *.[568vq]
 [568vq].out

vendor/github.com/prometheus/client_golang/.travis.yml

@@ -2,8 +2,9 @@ sudo: false
 language: go
 
 go:
- - 1.5.4
- - 1.6.2
+ - 1.7.x
+ - 1.8.x
+ - 1.9.x
 
 script:
- - go test -short ./... 
+ - go test -short ./...

vendor/github.com/prometheus/client_golang/AUTHORS.md

@@ -1,18 +0,0 @@
-The Prometheus project was started by Matt T. Proud (emeritus) and
-Julius Volz in 2012.
-
-Maintainers of this repository:
-
-* Björn Rabenstein <beorn@soundcloud.com>
-
-The following individuals have contributed code to this repository
-(listed in alphabetical order):
-
-* Bernerd Schaefer <bj.schaefer@gmail.com>
-* Björn Rabenstein <beorn@soundcloud.com>
-* Daniel Bornkessel <daniel@soundcloud.com>
-* Jeff Younker <jeff@drinktomi.com>
-* Julius Volz <julius.volz@gmail.com>
-* Matt T. Proud <matt.proud@gmail.com>
-* Tobias Schmidt <ts@soundcloud.com>
-

vendor/github.com/prometheus/client_golang/CONTRIBUTING.md

@@ -2,9 +2,9 @@
 
 Prometheus uses GitHub to manage reviews of pull requests.
 
-* If you have a trivial fix or improvement, go ahead and create a pull
-  request, addressing (with `@...`) one or more of the maintainers
-  (see [AUTHORS.md](AUTHORS.md)) in the description of the pull request.
+* If you have a trivial fix or improvement, go ahead and create a pull request,
+  addressing (with `@...`) the maintainer of this repository (see
+  [MAINTAINERS.md](MAINTAINERS.md)) in the description of the pull request.
 
 * If you plan to do something more involved, first discuss your ideas
   on our [mailing list](https://groups.google.com/forum/?fromgroups#!forum/prometheus-developers).

vendor/github.com/prometheus/client_golang/MAINTAINERS.md

@@ -0,0 +1 @@
+* Björn Rabenstein <beorn@soundcloud.com>

vendor/github.com/prometheus/client_golang/README.md

@@ -1,12 +1,15 @@
 # Prometheus Go client library
 
 [![Build Status](https://travis-ci.org/prometheus/client_golang.svg?branch=master)](https://travis-ci.org/prometheus/client_golang)
+[![Go Report Card](https://goreportcard.com/badge/github.com/prometheus/client_golang)](https://goreportcard.com/report/github.com/prometheus/client_golang)
 
 This is the [Go](http://golang.org) client library for
 [Prometheus](http://prometheus.io). It has two separate parts, one for
 instrumenting application code, and one for creating clients that talk to the
 Prometheus HTTP API.
 
+__This library requires Go1.7 or later.__
+
 ## Instrumenting applications
 
 [![code-coverage](http://gocover.io/_badge/github.com/prometheus/client_golang/prometheus)](http://gocover.io/github.com/prometheus/client_golang/prometheus) [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus)
@@ -29,7 +32,8 @@ The
 [`api/prometheus` directory](https://github.com/prometheus/client_golang/tree/master/api/prometheus)
 contains the client for the
 [Prometheus HTTP API](http://prometheus.io/docs/querying/api/). It allows you
-to write Go applications that query time series data from a Prometheus server.
+to write Go applications that query time series data from a Prometheus
+server. It is still in alpha stage.
 
 ## Where is `model`, `extraction`, and `text`?
 

vendor/github.com/prometheus/client_golang/api/client.go

@@ -0,0 +1,131 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.7
+
+// Package api provides clients for the HTTP APIs.
+package api
+
+import (
+	"context"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"path"
+	"strings"
+	"time"
+)
+
+// DefaultRoundTripper is used if no RoundTripper is set in Config.
+var DefaultRoundTripper http.RoundTripper = &http.Transport{
+	Proxy: http.ProxyFromEnvironment,
+	Dial: (&net.Dialer{
+		Timeout:   30 * time.Second,
+		KeepAlive: 30 * time.Second,
+	}).Dial,
+	TLSHandshakeTimeout: 10 * time.Second,
+}
+
+// Config defines configuration parameters for a new client.
+type Config struct {
+	// The address of the Prometheus to connect to.
+	Address string
+
+	// RoundTripper is used by the Client to drive HTTP requests. If not
+	// provided, DefaultRoundTripper will be used.
+	RoundTripper http.RoundTripper
+}
+
+func (cfg *Config) roundTripper() http.RoundTripper {
+	if cfg.RoundTripper == nil {
+		return DefaultRoundTripper
+	}
+	return cfg.RoundTripper
+}
+
+// Client is the interface for an API client.
+type Client interface {
+	URL(ep string, args map[string]string) *url.URL
+	Do(context.Context, *http.Request) (*http.Response, []byte, error)
+}
+
+// NewClient returns a new Client.
+//
+// It is safe to use the returned Client from multiple goroutines.
+func NewClient(cfg Config) (Client, error) {
+	u, err := url.Parse(cfg.Address)
+	if err != nil {
+		return nil, err
+	}
+	u.Path = strings.TrimRight(u.Path, "/")
+
+	return &httpClient{
+		endpoint: u,
+		client:   http.Client{Transport: cfg.roundTripper()},
+	}, nil
+}
+
+type httpClient struct {
+	endpoint *url.URL
+	client   http.Client
+}
+
+func (c *httpClient) URL(ep string, args map[string]string) *url.URL {
+	p := path.Join(c.endpoint.Path, ep)
+
+	for arg, val := range args {
+		arg = ":" + arg
+		p = strings.Replace(p, arg, val, -1)
+	}
+
+	u := *c.endpoint
+	u.Path = p
+
+	return &u
+}
+
+func (c *httpClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
+	if ctx != nil {
+		req = req.WithContext(ctx)
+	}
+	resp, err := c.client.Do(req)
+	defer func() {
+		if resp != nil {
+			resp.Body.Close()
+		}
+	}()
+
+	if err != nil {
+		return nil, nil, err
+	}
+
+	var body []byte
+	done := make(chan struct{})
+	go func() {
+		body, err = ioutil.ReadAll(resp.Body)
+		close(done)
+	}()
+
+	select {
+	case <-ctx.Done():
+		err = resp.Body.Close()
+		<-done
+		if err == nil {
+			err = ctx.Err()
+		}
+	case <-done:
+	}
+
+	return resp, body, err
+}

vendor/github.com/prometheus/client_golang/api/client_test.go

@@ -0,0 +1,115 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.7
+
+package api
+
+import (
+	"net/http"
+	"net/url"
+	"testing"
+)
+
+func TestConfig(t *testing.T) {
+	c := Config{}
+	if c.roundTripper() != DefaultRoundTripper {
+		t.Fatalf("expected default roundtripper for nil RoundTripper field")
+	}
+}
+
+func TestClientURL(t *testing.T) {
+	tests := []struct {
+		address  string
+		endpoint string
+		args     map[string]string
+		expected string
+	}{
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test",
+			expected: "http://localhost:9090/test",
+		},
+		{
+			address:  "http://localhost",
+			endpoint: "/test",
+			expected: "http://localhost/test",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "test",
+			expected: "http://localhost:9090/test",
+		},
+		{
+			address:  "http://localhost:9090/prefix",
+			endpoint: "/test",
+			expected: "http://localhost:9090/prefix/test",
+		},
+		{
+			address:  "https://localhost:9090/",
+			endpoint: "/test/",
+			expected: "https://localhost:9090/test",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test/:param",
+			args: map[string]string{
+				"param": "content",
+			},
+			expected: "http://localhost:9090/test/content",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test/:param/more/:param",
+			args: map[string]string{
+				"param": "content",
+			},
+			expected: "http://localhost:9090/test/content/more/content",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test/:param/more/:foo",
+			args: map[string]string{
+				"param": "content",
+				"foo":   "bar",
+			},
+			expected: "http://localhost:9090/test/content/more/bar",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test/:param",
+			args: map[string]string{
+				"nonexistant": "content",
+			},
+			expected: "http://localhost:9090/test/:param",
+		},
+	}
+
+	for _, test := range tests {
+		ep, err := url.Parse(test.address)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		hclient := &httpClient{
+			endpoint: ep,
+			client:   http.Client{Transport: DefaultRoundTripper},
+		}
+
+		u := hclient.URL(test.endpoint, test.args)
+		if u.String() != test.expected {
+			t.Errorf("unexpected result: got %s, want %s", u, test.expected)
+			continue
+		}
+	}
+}

vendor/github.com/prometheus/client_golang/api/prometheus/v1/api.go

@@ -1,4 +1,4 @@
-// Copyright 2015 The Prometheus Authors
+// Copyright 2017 The Prometheus Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
@@ -11,41 +11,40 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package prometheus provides bindings to the Prometheus HTTP API:
+// +build go1.7
+
+// Package v1 provides bindings to the Prometheus HTTP API v1:
 // http://prometheus.io/docs/querying/api/
-package prometheus
+package v1
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
-	"net"
 	"net/http"
-	"net/url"
-	"path"
 	"strconv"
-	"strings"
 	"time"
 
+	"github.com/prometheus/client_golang/api"
 	"github.com/prometheus/common/model"
-	"golang.org/x/net/context"
-	"golang.org/x/net/context/ctxhttp"
 )
 
 const (
 	statusAPIError = 422
-	apiPrefix      = "/api/v1"
 
-	epQuery       = "/query"
-	epQueryRange  = "/query_range"
-	epLabelValues = "/label/:name/values"
-	epSeries      = "/series"
+	apiPrefix = "/api/v1"
+
+	epQuery       = apiPrefix + "/query"
+	epQueryRange  = apiPrefix + "/query_range"
+	epLabelValues = apiPrefix + "/label/:name/values"
+	epSeries      = apiPrefix + "/series"
 )
 
+// ErrorType models the different API error types.
 type ErrorType string
 
+// Possible values for ErrorType.
 const (
-	// The different API error types.
 	ErrBadData     ErrorType = "bad_data"
 	ErrTimeout               = "timeout"
 	ErrCanceled              = "canceled"
@@ -63,166 +62,6 @@ func (e *Error) Error() string {
 	return fmt.Sprintf("%s: %s", e.Type, e.Msg)
 }
 
-// CancelableTransport is like net.Transport but provides
-// per-request cancelation functionality.
-type CancelableTransport interface {
-	http.RoundTripper
-	CancelRequest(req *http.Request)
-}
-
-var DefaultTransport CancelableTransport = &http.Transport{
-	Proxy: http.ProxyFromEnvironment,
-	Dial: (&net.Dialer{
-		Timeout:   30 * time.Second,
-		KeepAlive: 30 * time.Second,
-	}).Dial,
-	TLSHandshakeTimeout: 10 * time.Second,
-}
-
-// Config defines configuration parameters for a new client.
-type Config struct {
-	// The address of the Prometheus to connect to.
-	Address string
-
-	// Transport is used by the Client to drive HTTP requests. If not
-	// provided, DefaultTransport will be used.
-	Transport CancelableTransport
-}
-
-func (cfg *Config) transport() CancelableTransport {
-	if cfg.Transport == nil {
-		return DefaultTransport
-	}
-	return cfg.Transport
-}
-
-type Client interface {
-	url(ep string, args map[string]string) *url.URL
-	do(context.Context, *http.Request) (*http.Response, []byte, error)
-}
-
-// New returns a new Client.
-//
-// It is safe to use the returned Client from multiple goroutines.
-func New(cfg Config) (Client, error) {
-	u, err := url.Parse(cfg.Address)
-	if err != nil {
-		return nil, err
-	}
-	u.Path = strings.TrimRight(u.Path, "/") + apiPrefix
-
-	return &httpClient{
-		endpoint:  u,
-		transport: cfg.transport(),
-	}, nil
-}
-
-type httpClient struct {
-	endpoint  *url.URL
-	transport CancelableTransport
-}
-
-func (c *httpClient) url(ep string, args map[string]string) *url.URL {
-	p := path.Join(c.endpoint.Path, ep)
-
-	for arg, val := range args {
-		arg = ":" + arg
-		p = strings.Replace(p, arg, val, -1)
-	}
-
-	u := *c.endpoint
-	u.Path = p
-
-	return &u
-}
-
-func (c *httpClient) do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
-	resp, err := ctxhttp.Do(ctx, &http.Client{Transport: c.transport}, req)
-
-	defer func() {
-		if resp != nil {
-			resp.Body.Close()
-		}
-	}()
-
-	if err != nil {
-		return nil, nil, err
-	}
-
-	var body []byte
-	done := make(chan struct{})
-	go func() {
-		body, err = ioutil.ReadAll(resp.Body)
-		close(done)
-	}()
-
-	select {
-	case <-ctx.Done():
-		err = resp.Body.Close()
-		<-done
-		if err == nil {
-			err = ctx.Err()
-		}
-	case <-done:
-	}
-
-	return resp, body, err
-}
-
-// apiClient wraps a regular client and processes successful API responses.
-// Successful also includes responses that errored at the API level.
-type apiClient struct {
-	Client
-}
-
-type apiResponse struct {
-	Status    string          `json:"status"`
-	Data      json.RawMessage `json:"data"`
-	ErrorType ErrorType       `json:"errorType"`
-	Error     string          `json:"error"`
-}
-
-func (c apiClient) do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
-	resp, body, err := c.Client.do(ctx, req)
-	if err != nil {
-		return resp, body, err
-	}
-
-	code := resp.StatusCode
-
-	if code/100 != 2 && code != statusAPIError {
-		return resp, body, &Error{
-			Type: ErrBadResponse,
-			Msg:  fmt.Sprintf("bad response code %d", resp.StatusCode),
-		}
-	}
-
-	var result apiResponse
-
-	if err = json.Unmarshal(body, &result); err != nil {
-		return resp, body, &Error{
-			Type: ErrBadResponse,
-			Msg:  err.Error(),
-		}
-	}
-
-	if (code == statusAPIError) != (result.Status == "error") {
-		err = &Error{
-			Type: ErrBadResponse,
-			Msg:  "inconsistent body for response code",
-		}
-	}
-
-	if code == statusAPIError && result.Status == "error" {
-		err = &Error{
-			Type: result.ErrorType,
-			Msg:  result.Error,
-		}
-	}
-
-	return resp, []byte(result.Data), err
-}
-
 // Range represents a sliced time range.
 type Range struct {
 	// The boundaries of the time range.
@@ -231,6 +70,18 @@ type Range struct {
 	Step time.Duration
 }
 
+// API provides bindings for Prometheus's v1 API.
+type API interface {
+	// Query performs a query for the given time.
+	Query(ctx context.Context, query string, ts time.Time) (model.Value, error)
+	// QueryRange performs a query for the given range.
+	QueryRange(ctx context.Context, query string, r Range) (model.Value, error)
+	// LabelValues performs a query for the values of the given label.
+	LabelValues(ctx context.Context, label string) (model.LabelValues, error)
+	// Series finds series by label matchers.
+	Series(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) ([]model.LabelSet, error)
+}
+
 // queryResult contains result data for a query.
 type queryResult struct {
 	Type   model.ValueType `json:"resultType"`
@@ -273,37 +124,34 @@ func (qr *queryResult) UnmarshalJSON(b []byte) error {
 	return err
 }
 
-// QueryAPI provides bindings the Prometheus's query API.
-type QueryAPI interface {
-	// Query performs a query for the given time.
-	Query(ctx context.Context, query string, ts time.Time) (model.Value, error)
-	// Query performs a query for the given range.
-	QueryRange(ctx context.Context, query string, r Range) (model.Value, error)
-}
-
-// NewQueryAPI returns a new QueryAPI for the client.
+// NewAPI returns a new API for the client.
 //
-// It is safe to use the returned QueryAPI from multiple goroutines.
-func NewQueryAPI(c Client) QueryAPI {
-	return &httpQueryAPI{client: apiClient{c}}
+// It is safe to use the returned API from multiple goroutines.
+func NewAPI(c api.Client) API {
+	return &httpAPI{client: apiClient{c}}
 }
 
-type httpQueryAPI struct {
-	client Client
+type httpAPI struct {
+	client api.Client
 }
 
-func (h *httpQueryAPI) Query(ctx context.Context, query string, ts time.Time) (model.Value, error) {
-	u := h.client.url(epQuery, nil)
+func (h *httpAPI) Query(ctx context.Context, query string, ts time.Time) (model.Value, error) {
+	u := h.client.URL(epQuery, nil)
 	q := u.Query()
 
 	q.Set("query", query)
-	q.Set("time", ts.Format(time.RFC3339Nano))
+	if !ts.IsZero() {
+		q.Set("time", ts.Format(time.RFC3339Nano))
+	}
 
 	u.RawQuery = q.Encode()
 
-	req, _ := http.NewRequest("GET", u.String(), nil)
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
 
-	_, body, err := h.client.do(ctx, req)
+	_, body, err := h.client.Do(ctx, req)
 	if err != nil {
 		return nil, err
 	}
@@ -314,8 +162,8 @@ func (h *httpQueryAPI) Query(ctx context.Context, query string, ts time.Time) (m
 	return model.Value(qres.v), err
 }
 
-func (h *httpQueryAPI) QueryRange(ctx context.Context, query string, r Range) (model.Value, error) {
-	u := h.client.url(epQueryRange, nil)
+func (h *httpAPI) QueryRange(ctx context.Context, query string, r Range) (model.Value, error) {
+	u := h.client.URL(epQueryRange, nil)
 	q := u.Query()
 
 	var (
@@ -331,9 +179,12 @@ func (h *httpQueryAPI) QueryRange(ctx context.Context, query string, r Range) (m
 
 	u.RawQuery = q.Encode()
 
-	req, _ := http.NewRequest("GET", u.String(), nil)
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
 
-	_, body, err := h.client.do(ctx, req)
+	_, body, err := h.client.Do(ctx, req)
 	if err != nil {
 		return nil, err
 	}
@@ -343,3 +194,100 @@ func (h *httpQueryAPI) QueryRange(ctx context.Context, query string, r Range) (m
 
 	return model.Value(qres.v), err
 }
+
+func (h *httpAPI) LabelValues(ctx context.Context, label string) (model.LabelValues, error) {
+	u := h.client.URL(epLabelValues, map[string]string{"name": label})
+	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+	_, body, err := h.client.Do(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	var labelValues model.LabelValues
+	err = json.Unmarshal(body, &labelValues)
+	return labelValues, err
+}
+
+func (h *httpAPI) Series(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) ([]model.LabelSet, error) {
+	u := h.client.URL(epSeries, nil)
+	q := u.Query()
+
+	for _, m := range matches {
+		q.Add("match[]", m)
+	}
+
+	q.Set("start", startTime.Format(time.RFC3339Nano))
+	q.Set("end", endTime.Format(time.RFC3339Nano))
+
+	u.RawQuery = q.Encode()
+
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	_, body, err := h.client.Do(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	var mset []model.LabelSet
+	err = json.Unmarshal(body, &mset)
+	return mset, err
+}
+
+// apiClient wraps a regular client and processes successful API responses.
+// Successful also includes responses that errored at the API level.
+type apiClient struct {
+	api.Client
+}
+
+type apiResponse struct {
+	Status    string          `json:"status"`
+	Data      json.RawMessage `json:"data"`
+	ErrorType ErrorType       `json:"errorType"`
+	Error     string          `json:"error"`
+}
+
+func (c apiClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
+	resp, body, err := c.Client.Do(ctx, req)
+	if err != nil {
+		return resp, body, err
+	}
+
+	code := resp.StatusCode
+
+	if code/100 != 2 && code != statusAPIError {
+		return resp, body, &Error{
+			Type: ErrBadResponse,
+			Msg:  fmt.Sprintf("bad response code %d", resp.StatusCode),
+		}
+	}
+
+	var result apiResponse
+
+	if err = json.Unmarshal(body, &result); err != nil {
+		return resp, body, &Error{
+			Type: ErrBadResponse,
+			Msg:  err.Error(),
+		}
+	}
+
+	if (code == statusAPIError) != (result.Status == "error") {
+		err = &Error{
+			Type: ErrBadResponse,
+			Msg:  "inconsistent body for response code",
+		}
+	}
+
+	if code == statusAPIError && result.Status == "error" {
+		err = &Error{
+			Type: result.ErrorType,
+			Msg:  result.Error,
+		}
+	}
+
+	return resp, []byte(result.Data), err
+}

vendor/github.com/prometheus/client_golang/api/prometheus/v1/api_test.go

@@ -1,4 +1,4 @@
-// Copyright 2015 The Prometheus Authors
+// Copyright 2017 The Prometheus Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
@@ -11,118 +11,246 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package prometheus
+// +build go1.7
+
+package v1
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
 	"net/url"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 
 	"github.com/prometheus/common/model"
-	"golang.org/x/net/context"
 )
 
-func TestConfig(t *testing.T) {
-	c := Config{}
-	if c.transport() != DefaultTransport {
-		t.Fatalf("expected default transport for nil Transport field")
-	}
+type apiTest struct {
+	do    func() (interface{}, error)
+	inErr error
+	inRes interface{}
+
+	reqPath   string
+	reqParam  url.Values
+	reqMethod string
+	res       interface{}
+	err       error
 }
 
-func TestClientURL(t *testing.T) {
-	tests := []struct {
-		address  string
-		endpoint string
-		args     map[string]string
-		expected string
-	}{
+type apiTestClient struct {
+	*testing.T
+	curTest apiTest
+}
+
+func (c *apiTestClient) URL(ep string, args map[string]string) *url.URL {
+	path := ep
+	for k, v := range args {
+		path = strings.Replace(path, ":"+k, v, -1)
+	}
+	u := &url.URL{
+		Host: "test:9090",
+		Path: path,
+	}
+	return u
+}
+
+func (c *apiTestClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
+
+	test := c.curTest
+
+	if req.URL.Path != test.reqPath {
+		c.Errorf("unexpected request path: want %s, got %s", test.reqPath, req.URL.Path)
+	}
+	if req.Method != test.reqMethod {
+		c.Errorf("unexpected request method: want %s, got %s", test.reqMethod, req.Method)
+	}
+
+	b, err := json.Marshal(test.inRes)
+	if err != nil {
+		c.Fatal(err)
+	}
+
+	resp := &http.Response{}
+	if test.inErr != nil {
+		resp.StatusCode = statusAPIError
+	} else {
+		resp.StatusCode = http.StatusOK
+	}
+
+	return resp, b, test.inErr
+}
+
+func TestAPIs(t *testing.T) {
+
+	testTime := time.Now()
+
+	client := &apiTestClient{T: t}
+
+	queryAPI := &httpAPI{
+		client: client,
+	}
+
+	doQuery := func(q string, ts time.Time) func() (interface{}, error) {
+		return func() (interface{}, error) {
+			return queryAPI.Query(context.Background(), q, ts)
+		}
+	}
+
+	doQueryRange := func(q string, rng Range) func() (interface{}, error) {
+		return func() (interface{}, error) {
+			return queryAPI.QueryRange(context.Background(), q, rng)
+		}
+	}
+
+	doLabelValues := func(label string) func() (interface{}, error) {
+		return func() (interface{}, error) {
+			return queryAPI.LabelValues(context.Background(), label)
+		}
+	}
+
+	doSeries := func(matcher string, startTime time.Time, endTime time.Time) func() (interface{}, error) {
+		return func() (interface{}, error) {
+			return queryAPI.Series(context.Background(), []string{matcher}, startTime, endTime)
+		}
+	}
+
+	queryTests := []apiTest{
 		{
-			address:  "http://localhost:9090",
-			endpoint: "/test",
-			expected: "http://localhost:9090/test",
-		},
-		{
-			address:  "http://localhost",
-			endpoint: "/test",
-			expected: "http://localhost/test",
-		},
-		{
-			address:  "http://localhost:9090",
-			endpoint: "test",
-			expected: "http://localhost:9090/test",
-		},
-		{
-			address:  "http://localhost:9090/prefix",
-			endpoint: "/test",
-			expected: "http://localhost:9090/prefix/test",
-		},
-		{
-			address:  "https://localhost:9090/",
-			endpoint: "/test/",
-			expected: "https://localhost:9090/test",
-		},
-		{
-			address:  "http://localhost:9090",
-			endpoint: "/test/:param",
-			args: map[string]string{
-				"param": "content",
+			do: doQuery("2", testTime),
+			inRes: &queryResult{
+				Type: model.ValScalar,
+				Result: &model.Scalar{
+					Value:     2,
+					Timestamp: model.TimeFromUnix(testTime.Unix()),
+				},
+			},
+
+			reqMethod: "GET",
+			reqPath:   "/api/v1/query",
+			reqParam: url.Values{
+				"query": []string{"2"},
+				"time":  []string{testTime.Format(time.RFC3339Nano)},
+			},
+			res: &model.Scalar{
+				Value:     2,
+				Timestamp: model.TimeFromUnix(testTime.Unix()),
 			},
-			expected: "http://localhost:9090/test/content",
 		},
 		{
-			address:  "http://localhost:9090",
-			endpoint: "/test/:param/more/:param",
-			args: map[string]string{
-				"param": "content",
+			do:    doQuery("2", testTime),
+			inErr: fmt.Errorf("some error"),
+
+			reqMethod: "GET",
+			reqPath:   "/api/v1/query",
+			reqParam: url.Values{
+				"query": []string{"2"},
+				"time":  []string{testTime.Format(time.RFC3339Nano)},
 			},
-			expected: "http://localhost:9090/test/content/more/content",
+			err: fmt.Errorf("some error"),
 		},
+
 		{
-			address:  "http://localhost:9090",
-			endpoint: "/test/:param/more/:foo",
-			args: map[string]string{
-				"param": "content",
-				"foo":   "bar",
+			do: doQueryRange("2", Range{
+				Start: testTime.Add(-time.Minute),
+				End:   testTime,
+				Step:  time.Minute,
+			}),
+			inErr: fmt.Errorf("some error"),
+
+			reqMethod: "GET",
+			reqPath:   "/api/v1/query_range",
+			reqParam: url.Values{
+				"query": []string{"2"},
+				"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
+				"end":   []string{testTime.Format(time.RFC3339Nano)},
+				"step":  []string{time.Minute.String()},
 			},
-			expected: "http://localhost:9090/test/content/more/bar",
+			err: fmt.Errorf("some error"),
 		},
+
 		{
-			address:  "http://localhost:9090",
-			endpoint: "/test/:param",
-			args: map[string]string{
-				"nonexistant": "content",
+			do:        doLabelValues("mylabel"),
+			inRes:     []string{"val1", "val2"},
+			reqMethod: "GET",
+			reqPath:   "/api/v1/label/mylabel/values",
+			res:       model.LabelValues{"val1", "val2"},
+		},
+
+		{
+			do:        doLabelValues("mylabel"),
+			inErr:     fmt.Errorf("some error"),
+			reqMethod: "GET",
+			reqPath:   "/api/v1/label/mylabel/values",
+			err:       fmt.Errorf("some error"),
+		},
+
+		{
+			do: doSeries("up", testTime.Add(-time.Minute), testTime),
+			inRes: []map[string]string{
+				{
+					"__name__": "up",
+					"job":      "prometheus",
+					"instance": "localhost:9090"},
 			},
-			expected: "http://localhost:9090/test/:param",
+			reqMethod: "GET",
+			reqPath:   "/api/v1/series",
+			reqParam: url.Values{
+				"match": []string{"up"},
+				"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
+				"end":   []string{testTime.Format(time.RFC3339Nano)},
+			},
+			res: []model.LabelSet{
+				model.LabelSet{
+					"__name__": "up",
+					"job":      "prometheus",
+					"instance": "localhost:9090",
+				},
+			},
+		},
+
+		{
+			do:        doSeries("up", testTime.Add(-time.Minute), testTime),
+			inErr:     fmt.Errorf("some error"),
+			reqMethod: "GET",
+			reqPath:   "/api/v1/series",
+			reqParam: url.Values{
+				"match": []string{"up"},
+				"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
+				"end":   []string{testTime.Format(time.RFC3339Nano)},
+			},
+			err: fmt.Errorf("some error"),
 		},
 	}
 
+	var tests []apiTest
+	tests = append(tests, queryTests...)
+
 	for _, test := range tests {
-		ep, err := url.Parse(test.address)
+		client.curTest = test
+
+		res, err := test.do()
+
+		if test.err != nil {
+			if err == nil {
+				t.Errorf("expected error %q but got none", test.err)
+				continue
+			}
+			if err.Error() != test.err.Error() {
+				t.Errorf("unexpected error: want %s, got %s", test.err, err)
+			}
+			continue
+		}
 		if err != nil {
-			t.Fatal(err)
-		}
-
-		hclient := &httpClient{
-			endpoint:  ep,
-			transport: DefaultTransport,
-		}
-
-		u := hclient.url(test.endpoint, test.args)
-		if u.String() != test.expected {
-			t.Errorf("unexpected result: got %s, want %s", u, test.expected)
+			t.Errorf("unexpected error: %s", err)
 			continue
 		}
 
-		// The apiClient must return exactly the same result as the httpClient.
-		aclient := &apiClient{hclient}
-
-		u = aclient.url(test.endpoint, test.args)
-		if u.String() != test.expected {
-			t.Errorf("unexpected result: got %s, want %s", u, test.expected)
+		if !reflect.DeepEqual(res, test.res) {
+			t.Errorf("unexpected result: want %v, got %v", test.res, res)
 		}
 	}
 }
@@ -141,11 +269,11 @@ type apiClientTest struct {
 	err      *Error
 }
 
-func (c *testClient) url(ep string, args map[string]string) *url.URL {
+func (c *testClient) URL(ep string, args map[string]string) *url.URL {
 	return nil
 }
 
-func (c *testClient) do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
+func (c *testClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
 	if ctx == nil {
 		c.Fatalf("context was not passed down")
 	}
@@ -271,7 +399,7 @@ func TestAPIClientDo(t *testing.T) {
 
 		tc.ch <- test
 
-		_, body, err := client.do(context.Background(), tc.req)
+		_, body, err := client.Do(context.Background(), tc.req)
 
 		if test.err != nil {
 			if err == nil {
@@ -294,160 +422,3 @@ func TestAPIClientDo(t *testing.T) {
 		}
 	}
 }
-
-type apiTestClient struct {
-	*testing.T
-	curTest apiTest
-}
-
-type apiTest struct {
-	do    func() (interface{}, error)
-	inErr error
-	inRes interface{}
-
-	reqPath   string
-	reqParam  url.Values
-	reqMethod string
-	res       interface{}
-	err       error
-}
-
-func (c *apiTestClient) url(ep string, args map[string]string) *url.URL {
-	u := &url.URL{
-		Host: "test:9090",
-		Path: apiPrefix + ep,
-	}
-	return u
-}
-
-func (c *apiTestClient) do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
-
-	test := c.curTest
-
-	if req.URL.Path != test.reqPath {
-		c.Errorf("unexpected request path: want %s, got %s", test.reqPath, req.URL.Path)
-	}
-	if req.Method != test.reqMethod {
-		c.Errorf("unexpected request method: want %s, got %s", test.reqMethod, req.Method)
-	}
-
-	b, err := json.Marshal(test.inRes)
-	if err != nil {
-		c.Fatal(err)
-	}
-
-	resp := &http.Response{}
-	if test.inErr != nil {
-		resp.StatusCode = statusAPIError
-	} else {
-		resp.StatusCode = http.StatusOK
-	}
-
-	return resp, b, test.inErr
-}
-
-func TestAPIs(t *testing.T) {
-
-	testTime := time.Now()
-
-	client := &apiTestClient{T: t}
-
-	queryApi := &httpQueryAPI{
-		client: client,
-	}
-
-	doQuery := func(q string, ts time.Time) func() (interface{}, error) {
-		return func() (interface{}, error) {
-			return queryApi.Query(context.Background(), q, ts)
-		}
-	}
-
-	doQueryRange := func(q string, rng Range) func() (interface{}, error) {
-		return func() (interface{}, error) {
-			return queryApi.QueryRange(context.Background(), q, rng)
-		}
-	}
-
-	queryTests := []apiTest{
-		{
-			do: doQuery("2", testTime),
-			inRes: &queryResult{
-				Type: model.ValScalar,
-				Result: &model.Scalar{
-					Value:     2,
-					Timestamp: model.TimeFromUnix(testTime.Unix()),
-				},
-			},
-
-			reqMethod: "GET",
-			reqPath:   "/api/v1/query",
-			reqParam: url.Values{
-				"query": []string{"2"},
-				"time":  []string{testTime.Format(time.RFC3339Nano)},
-			},
-			res: &model.Scalar{
-				Value:     2,
-				Timestamp: model.TimeFromUnix(testTime.Unix()),
-			},
-		},
-		{
-			do:    doQuery("2", testTime),
-			inErr: fmt.Errorf("some error"),
-
-			reqMethod: "GET",
-			reqPath:   "/api/v1/query",
-			reqParam: url.Values{
-				"query": []string{"2"},
-				"time":  []string{testTime.Format(time.RFC3339Nano)},
-			},
-			err: fmt.Errorf("some error"),
-		},
-
-		{
-			do: doQueryRange("2", Range{
-				Start: testTime.Add(-time.Minute),
-				End:   testTime,
-				Step:  time.Minute,
-			}),
-			inErr: fmt.Errorf("some error"),
-
-			reqMethod: "GET",
-			reqPath:   "/api/v1/query_range",
-			reqParam: url.Values{
-				"query": []string{"2"},
-				"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
-				"end":   []string{testTime.Format(time.RFC3339Nano)},
-				"step":  []string{time.Minute.String()},
-			},
-			err: fmt.Errorf("some error"),
-		},
-	}
-
-	var tests []apiTest
-	tests = append(tests, queryTests...)
-
-	for _, test := range tests {
-		client.curTest = test
-
-		res, err := test.do()
-
-		if test.err != nil {
-			if err == nil {
-				t.Errorf("expected error %q but got none", test.err)
-				continue
-			}
-			if err.Error() != test.err.Error() {
-				t.Errorf("unexpected error: want %s, got %s", test.err, err)
-			}
-			continue
-		}
-		if err != nil {
-			t.Errorf("unexpected error: %s", err)
-			continue
-		}
-
-		if !reflect.DeepEqual(res, test.res) {
-			t.Errorf("unexpected result: want %v, got %v", test.res, res)
-		}
-	}
-}

vendor/github.com/prometheus/client_golang/examples/random/Dockerfile

@@ -0,0 +1,20 @@
+# This Dockerfile builds an image for a client_golang example.
+#
+# Use as (from the root for the client_golang repository):
+#    docker build -f examples/$name/Dockerfile -t prometheus/golang-example-$name .
+
+# Builder image, where we build the example.
+FROM golang:1.9.0 AS builder
+WORKDIR /go/src/github.com/prometheus/client_golang
+COPY . .
+WORKDIR /go/src/github.com/prometheus/client_golang/prometheus
+RUN go get -d
+WORKDIR /go/src/github.com/prometheus/client_golang/examples/random
+RUN CGO_ENABLED=0 GOOS=linux go build -a -tags netgo -ldflags '-w'
+
+# Final image.
+FROM scratch
+LABEL maintainer "The Prometheus Authors <prometheus-developers@googlegroups.com>"
+COPY --from=builder /go/src/github.com/prometheus/client_golang/examples/random .
+EXPOSE 8080
+ENTRYPOINT ["/random"]

vendor/github.com/prometheus/client_golang/examples/random/main.go

@@ -18,19 +18,21 @@ package main
 
 import (
 	"flag"
+	"log"
 	"math"
 	"math/rand"
 	"net/http"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 var (
 	addr              = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
-	uniformDomain     = flag.Float64("uniform.domain", 200, "The domain for the uniform distribution.")
-	normDomain        = flag.Float64("normal.domain", 200, "The domain for the normal distribution.")
-	normMean          = flag.Float64("normal.mean", 10, "The mean for the normal distribution.")
+	uniformDomain     = flag.Float64("uniform.domain", 0.0002, "The domain for the uniform distribution.")
+	normDomain        = flag.Float64("normal.domain", 0.0002, "The domain for the normal distribution.")
+	normMean          = flag.Float64("normal.mean", 0.00001, "The mean for the normal distribution.")
 	oscillationPeriod = flag.Duration("oscillation-period", 10*time.Minute, "The duration of the rate oscillation period.")
 )
 
@@ -40,8 +42,9 @@ var (
 	// differentiated via a "service" label.
 	rpcDurations = prometheus.NewSummaryVec(
 		prometheus.SummaryOpts{
-			Name: "rpc_durations_microseconds",
-			Help: "RPC latency distributions.",
+			Name:       "rpc_durations_seconds",
+			Help:       "RPC latency distributions.",
+			Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 		},
 		[]string{"service"},
 	)
@@ -50,7 +53,7 @@ var (
 	// normal distribution, with 20 buckets centered on the mean, each
 	// half-sigma wide.
 	rpcDurationsHistogram = prometheus.NewHistogram(prometheus.HistogramOpts{
-		Name:    "rpc_durations_histogram_microseconds",
+		Name:    "rpc_durations_histogram_seconds",
 		Help:    "RPC latency distributions.",
 		Buckets: prometheus.LinearBuckets(*normMean-5**normDomain, .5**normDomain, 20),
 	})
@@ -91,13 +94,13 @@ func main() {
 
 	go func() {
 		for {
-			v := rand.ExpFloat64()
+			v := rand.ExpFloat64() / 1e6
 			rpcDurations.WithLabelValues("exponential").Observe(v)
 			time.Sleep(time.Duration(50*oscillationFactor()) * time.Millisecond)
 		}
 	}()
 
 	// Expose the registered metrics via HTTP.
-	http.Handle("/metrics", prometheus.Handler())
-	http.ListenAndServe(*addr, nil)
+	http.Handle("/metrics", promhttp.Handler())
+	log.Fatal(http.ListenAndServe(*addr, nil))
 }

vendor/github.com/prometheus/client_golang/examples/simple/Dockerfile

@@ -0,0 +1,20 @@
+# This Dockerfile builds an image for a client_golang example.
+#
+# Use as (from the root for the client_golang repository):
+#    docker build -f examples/$name/Dockerfile -t prometheus/golang-example-$name .
+
+# Builder image, where we build the example.
+FROM golang:1.9.0 AS builder
+WORKDIR /go/src/github.com/prometheus/client_golang
+COPY . .
+WORKDIR /go/src/github.com/prometheus/client_golang/prometheus
+RUN go get -d
+WORKDIR /go/src/github.com/prometheus/client_golang/examples/simple
+RUN CGO_ENABLED=0 GOOS=linux go build -a -tags netgo -ldflags '-w'
+
+# Final image.
+FROM scratch
+LABEL maintainer "The Prometheus Authors <prometheus-developers@googlegroups.com>"
+COPY --from=builder /go/src/github.com/prometheus/client_golang/examples/simple .
+EXPOSE 8080
+ENTRYPOINT ["/simple"]

vendor/github.com/prometheus/client_golang/examples/simple/main.go

@@ -16,15 +16,16 @@ package main
 
 import (
 	"flag"
+	"log"
 	"net/http"
 
-	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 var addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
 
 func main() {
 	flag.Parse()
-	http.Handle("/metrics", prometheus.Handler())
-	http.ListenAndServe(*addr, nil)
+	http.Handle("/metrics", promhttp.Handler())
+	log.Fatal(http.ListenAndServe(*addr, nil))
 }

vendor/github.com/prometheus/client_golang/prometheus/benchmark_test.go

@@ -129,8 +129,9 @@ func BenchmarkGaugeNoLabels(b *testing.B) {
 func BenchmarkSummaryWithLabelValues(b *testing.B) {
 	m := NewSummaryVec(
 		SummaryOpts{
-			Name: "benchmark_summary",
-			Help: "A summary to benchmark it.",
+			Name:       "benchmark_summary",
+			Help:       "A summary to benchmark it.",
+			Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 		},
 		[]string{"one", "two", "three"},
 	)
@@ -143,8 +144,9 @@ func BenchmarkSummaryWithLabelValues(b *testing.B) {
 
 func BenchmarkSummaryNoLabels(b *testing.B) {
 	m := NewSummary(SummaryOpts{
-		Name: "benchmark_summary",
-		Help: "A summary to benchmark it.",
+		Name:       "benchmark_summary",
+		Help:       "A summary to benchmark it.",
+		Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 	},
 	)
 	b.ReportAllocs()
@@ -181,3 +183,17 @@ func BenchmarkHistogramNoLabels(b *testing.B) {
 		m.Observe(3.1415)
 	}
 }
+
+func BenchmarkParallelCounter(b *testing.B) {
+	c := NewCounter(CounterOpts{
+		Name: "benchmark_counter",
+		Help: "A Counter to benchmark it.",
+	})
+	b.ReportAllocs()
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			c.Inc()
+		}
+	})
+}

vendor/github.com/prometheus/client_golang/prometheus/counter.go

@@ -15,6 +15,10 @@ package prometheus
 
 import (
 	"errors"
+	"math"
+	"sync/atomic"
+
+	dto "github.com/prometheus/client_model/go"
 )
 
 // Counter is a Metric that represents a single numerical value that only ever
@@ -30,16 +34,8 @@ type Counter interface {
 	Metric
 	Collector
 
-	// Set is used to set the Counter to an arbitrary value. It is only used
-	// if you have to transfer a value from an external counter into this
-	// Prometheus metric. Do not use it for regular handling of a
-	// Prometheus counter (as it can be used to break the contract of
-	// monotonically increasing values).
-	//
-	// Deprecated: Use NewConstMetric to create a counter for an external
-	// value. A Counter should never be set.
-	Set(float64)
-	// Inc increments the counter by 1.
+	// Inc increments the counter by 1. Use Add to increment it by arbitrary
+	// non-negative values.
 	Inc()
 	// Add adds the given value to the counter. It panics if the value is <
 	// 0.
@@ -50,6 +46,14 @@ type Counter interface {
 type CounterOpts Opts
 
 // NewCounter creates a new Counter based on the provided CounterOpts.
+//
+// The returned implementation tracks the counter value in two separate
+// variables, a float64 and a uint64. The latter is used to track calls of the
+// Inc method and calls of the Add method with a value that can be represented
+// as a uint64. This allows atomic increments of the counter with optimal
+// performance. (It is common to have an Inc call in very hot execution paths.)
+// Both internal tracking values are added up in the Write method. This has to
+// be taken into account when it comes to precision and overflow behavior.
 func NewCounter(opts CounterOpts) Counter {
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
@@ -57,20 +61,58 @@ func NewCounter(opts CounterOpts) Counter {
 		nil,
 		opts.ConstLabels,
 	)
-	result := &counter{value: value{desc: desc, valType: CounterValue, labelPairs: desc.constLabelPairs}}
+	result := &counter{desc: desc, labelPairs: desc.constLabelPairs}
 	result.init(result) // Init self-collection.
 	return result
 }
 
 type counter struct {
-	value
+	// valBits contains the bits of the represented float64 value, while
+	// valInt stores values that are exact integers. Both have to go first
+	// in the struct to guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+	valInt  uint64
+
+	selfCollector
+	desc *Desc
+
+	labelPairs []*dto.LabelPair
+}
+
+func (c *counter) Desc() *Desc {
+	return c.desc
 }
 
 func (c *counter) Add(v float64) {
 	if v < 0 {
 		panic(errors.New("counter cannot decrease in value"))
 	}
-	c.value.Add(v)
+	ival := uint64(v)
+	if float64(ival) == v {
+		atomic.AddUint64(&c.valInt, ival)
+		return
+	}
+
+	for {
+		oldBits := atomic.LoadUint64(&c.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&c.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (c *counter) Inc() {
+	atomic.AddUint64(&c.valInt, 1)
+}
+
+func (c *counter) Write(out *dto.Metric) error {
+	fval := math.Float64frombits(atomic.LoadUint64(&c.valBits))
+	ival := atomic.LoadUint64(&c.valInt)
+	val := fval + float64(ival)
+
+	return populateMetric(CounterValue, val, c.labelPairs, out)
 }
 
 // CounterVec is a Collector that bundles a set of Counters that all share the
@@ -78,16 +120,12 @@ func (c *counter) Add(v float64) {
 // if you want to count the same thing partitioned by various dimensions
 // (e.g. number of HTTP requests, partitioned by response code and
 // method). Create instances with NewCounterVec.
-//
-// CounterVec embeds MetricVec. See there for a full list of methods with
-// detailed documentation.
 type CounterVec struct {
-	*MetricVec
+	*metricVec
 }
 
 // NewCounterVec creates a new CounterVec based on the provided CounterOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
+// partitioned by the given label names.
 func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
@@ -96,34 +134,62 @@ func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
 		opts.ConstLabels,
 	)
 	return &CounterVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
-			result := &counter{value: value{
-				desc:       desc,
-				valType:    CounterValue,
-				labelPairs: makeLabelPairs(desc, lvs),
-			}}
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels) {
+				panic(errInconsistentCardinality)
+			}
+			result := &counter{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
 			result.init(result) // Init self-collection.
 			return result
 		}),
 	}
 }
 
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns a Counter and not a
-// Metric so that no type conversion is required.
-func (m *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+// GetMetricWithLabelValues returns the Counter for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Counter is created.
+//
+// It is possible to call this method without using the returned Counter to only
+// create the new Counter but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Counter for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Counter from the CounterVec. In that case,
+// the Counter will still exist, but it will not be exported anymore, even if a
+// Counter with the same label values is created later.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
 	if metric != nil {
 		return metric.(Counter), err
 	}
 	return nil, err
 }
 
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns a Counter and not a Metric so that no
-// type conversion is required.
-func (m *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
+// GetMetricWith returns the Counter for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Counter is created. Implications of
+// creating a Counter without using it and keeping the Counter for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
 	if metric != nil {
 		return metric.(Counter), err
 	}
@@ -131,18 +197,57 @@ func (m *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
 }
 
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
 //     myVec.WithLabelValues("404", "GET").Add(42)
-func (m *CounterVec) WithLabelValues(lvs ...string) Counter {
-	return m.MetricVec.WithLabelValues(lvs...).(Counter)
+func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
+	c, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return c
 }
 
 // With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
-func (m *CounterVec) With(labels Labels) Counter {
-	return m.MetricVec.With(labels).(Counter)
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *CounterVec) With(labels Labels) Counter {
+	c, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the CounterVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *CounterVec) CurryWith(labels Labels) (*CounterVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &CounterVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *CounterVec) MustCurryWith(labels Labels) *CounterVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
 }
 
 // CounterFunc is a Counter whose value is determined at collect time by calling a

vendor/github.com/prometheus/client_golang/prometheus/counter_test.go

@@ -14,6 +14,7 @@
 package prometheus
 
 import (
+	"fmt"
 	"math"
 	"testing"
 
@@ -27,13 +28,27 @@ func TestCounterAdd(t *testing.T) {
 		ConstLabels: Labels{"a": "1", "b": "2"},
 	}).(*counter)
 	counter.Inc()
-	if expected, got := 1., math.Float64frombits(counter.valBits); expected != got {
+	if expected, got := 0.0, math.Float64frombits(counter.valBits); expected != got {
 		t.Errorf("Expected %f, got %f.", expected, got)
 	}
+	if expected, got := uint64(1), counter.valInt; expected != got {
+		t.Errorf("Expected %d, got %d.", expected, got)
+	}
 	counter.Add(42)
-	if expected, got := 43., math.Float64frombits(counter.valBits); expected != got {
+	if expected, got := 0.0, math.Float64frombits(counter.valBits); expected != got {
 		t.Errorf("Expected %f, got %f.", expected, got)
 	}
+	if expected, got := uint64(43), counter.valInt; expected != got {
+		t.Errorf("Expected %d, got %d.", expected, got)
+	}
+
+	counter.Add(24.42)
+	if expected, got := 24.42, math.Float64frombits(counter.valBits); expected != got {
+		t.Errorf("Expected %f, got %f.", expected, got)
+	}
+	if expected, got := uint64(43), counter.valInt; expected != got {
+		t.Errorf("Expected %d, got %d.", expected, got)
+	}
 
 	if expected, got := "counter cannot decrease in value", decreaseCounter(counter).Error(); expected != got {
 		t.Errorf("Expected error %q, got %q.", expected, got)
@@ -42,7 +57,7 @@ func TestCounterAdd(t *testing.T) {
 	m := &dto.Metric{}
 	counter.Write(m)
 
-	if expected, got := `label:<name:"a" value:"1" > label:<name:"b" value:"2" > counter:<value:43 > `, m.String(); expected != got {
+	if expected, got := `label:<name:"a" value:"1" > label:<name:"b" value:"2" > counter:<value:67.42 > `, m.String(); expected != got {
 		t.Errorf("expected %q, got %q", expected, got)
 	}
 }
@@ -56,3 +71,142 @@ func decreaseCounter(c *counter) (err error) {
 	c.Add(-1)
 	return nil
 }
+
+func TestCounterVecGetMetricWithInvalidLabelValues(t *testing.T) {
+	testCases := []struct {
+		desc   string
+		labels Labels
+	}{
+		{
+			desc:   "non utf8 label value",
+			labels: Labels{"a": "\xFF"},
+		},
+		{
+			desc:   "not enough label values",
+			labels: Labels{},
+		},
+		{
+			desc:   "too many label values",
+			labels: Labels{"a": "1", "b": "2"},
+		},
+	}
+
+	for _, test := range testCases {
+		counterVec := NewCounterVec(CounterOpts{
+			Name: "test",
+		}, []string{"a"})
+
+		labelValues := make([]string, len(test.labels))
+		for _, val := range test.labels {
+			labelValues = append(labelValues, val)
+		}
+
+		expectPanic(t, func() {
+			counterVec.WithLabelValues(labelValues...)
+		}, fmt.Sprintf("WithLabelValues: expected panic because: %s", test.desc))
+		expectPanic(t, func() {
+			counterVec.With(test.labels)
+		}, fmt.Sprintf("WithLabelValues: expected panic because: %s", test.desc))
+
+		if _, err := counterVec.GetMetricWithLabelValues(labelValues...); err == nil {
+			t.Errorf("GetMetricWithLabelValues: expected error because: %s", test.desc)
+		}
+		if _, err := counterVec.GetMetricWith(test.labels); err == nil {
+			t.Errorf("GetMetricWith: expected error because: %s", test.desc)
+		}
+	}
+}
+
+func expectPanic(t *testing.T, op func(), errorMsg string) {
+	defer func() {
+		if err := recover(); err == nil {
+			t.Error(errorMsg)
+		}
+	}()
+
+	op()
+}
+
+func TestCounterAddInf(t *testing.T) {
+	counter := NewCounter(CounterOpts{
+		Name: "test",
+		Help: "test help",
+	}).(*counter)
+
+	counter.Inc()
+	if expected, got := 0.0, math.Float64frombits(counter.valBits); expected != got {
+		t.Errorf("Expected %f, got %f.", expected, got)
+	}
+	if expected, got := uint64(1), counter.valInt; expected != got {
+		t.Errorf("Expected %d, got %d.", expected, got)
+	}
+
+	counter.Add(math.Inf(1))
+	if expected, got := math.Inf(1), math.Float64frombits(counter.valBits); expected != got {
+		t.Errorf("valBits expected %f, got %f.", expected, got)
+	}
+	if expected, got := uint64(1), counter.valInt; expected != got {
+		t.Errorf("valInts expected %d, got %d.", expected, got)
+	}
+
+	counter.Inc()
+	if expected, got := math.Inf(1), math.Float64frombits(counter.valBits); expected != got {
+		t.Errorf("Expected %f, got %f.", expected, got)
+	}
+	if expected, got := uint64(2), counter.valInt; expected != got {
+		t.Errorf("Expected %d, got %d.", expected, got)
+	}
+
+	m := &dto.Metric{}
+	counter.Write(m)
+
+	if expected, got := `counter:<value:inf > `, m.String(); expected != got {
+		t.Errorf("expected %q, got %q", expected, got)
+	}
+}
+
+func TestCounterAddLarge(t *testing.T) {
+	counter := NewCounter(CounterOpts{
+		Name: "test",
+		Help: "test help",
+	}).(*counter)
+
+	// large overflows the underlying type and should therefore be stored in valBits.
+	large := float64(math.MaxUint64 + 1)
+	counter.Add(large)
+	if expected, got := large, math.Float64frombits(counter.valBits); expected != got {
+		t.Errorf("valBits expected %f, got %f.", expected, got)
+	}
+	if expected, got := uint64(0), counter.valInt; expected != got {
+		t.Errorf("valInts expected %d, got %d.", expected, got)
+	}
+
+	m := &dto.Metric{}
+	counter.Write(m)
+
+	if expected, got := fmt.Sprintf("counter:<value:%0.16e > ", large), m.String(); expected != got {
+		t.Errorf("expected %q, got %q", expected, got)
+	}
+}
+
+func TestCounterAddSmall(t *testing.T) {
+	counter := NewCounter(CounterOpts{
+		Name: "test",
+		Help: "test help",
+	}).(*counter)
+	small := 0.000000000001
+	counter.Add(small)
+	if expected, got := small, math.Float64frombits(counter.valBits); expected != got {
+		t.Errorf("valBits expected %f, got %f.", expected, got)
+	}
+	if expected, got := uint64(0), counter.valInt; expected != got {
+		t.Errorf("valInts expected %d, got %d.", expected, got)
+	}
+
+	m := &dto.Metric{}
+	counter.Write(m)
+
+	if expected, got := fmt.Sprintf("counter:<value:%0.0e > ", small), m.String(); expected != got {
+		t.Errorf("expected %q, got %q", expected, got)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/desc.go

@@ -16,33 +16,15 @@ package prometheus
 import (
 	"errors"
 	"fmt"
-	"regexp"
 	"sort"
 	"strings"
 
 	"github.com/golang/protobuf/proto"
+	"github.com/prometheus/common/model"
 
 	dto "github.com/prometheus/client_model/go"
 )
 
-var (
-	metricNameRE = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_:]*$`)
-	labelNameRE  = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
-)
-
-// reservedLabelPrefix is a prefix which is not legal in user-supplied
-// label names.
-const reservedLabelPrefix = "__"
-
-// Labels represents a collection of label name -> value mappings. This type is
-// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
-// metric vector Collectors, e.g.:
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
-//
-// The other use-case is the specification of constant label pairs in Opts or to
-// create a Desc.
-type Labels map[string]string
-
 // Desc is the descriptor used by every Prometheus Metric. It is essentially
 // the immutable meta-data of a Metric. The normal Metric implementations
 // included in this package manage their Desc under the hood. Users only have to
@@ -78,7 +60,7 @@ type Desc struct {
 	// Help string. Each Desc with the same fqName must have the same
 	// dimHash.
 	dimHash uint64
-	// err is an error that occured during construction. It is reported on
+	// err is an error that occurred during construction. It is reported on
 	// registration time.
 	err error
 }
@@ -91,8 +73,7 @@ type Desc struct {
 // and therefore not part of the Desc. (They are managed within the Metric.)
 //
 // For constLabels, the label values are constant. Therefore, they are fully
-// specified in the Desc. See the Opts documentation for the implications of
-// constant labels.
+// specified in the Desc. See the Collector example for a usage pattern.
 func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
 	d := &Desc{
 		fqName:         fqName,
@@ -103,7 +84,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 		d.err = errors.New("empty help string")
 		return d
 	}
-	if !metricNameRE.MatchString(fqName) {
+	if !model.IsValidMetricName(model.LabelValue(fqName)) {
 		d.err = fmt.Errorf("%q is not a valid metric name", fqName)
 		return d
 	}
@@ -127,6 +108,12 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 	for _, labelName := range labelNames {
 		labelValues = append(labelValues, constLabels[labelName])
 	}
+	// Validate the const label values. They can't have a wrong cardinality, so
+	// use in len(labelValues) as expectedNumberOfValues.
+	if err := validateLabelValues(labelValues, len(labelValues)); err != nil {
+		d.err = err
+		return d
+	}
 	// Now add the variable label names, but prefix them with something that
 	// cannot be in a regular label name. That prevents matching the label
 	// dimension with a different mix between preset and variable labels.
@@ -142,6 +129,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 		d.err = errors.New("duplicate label names")
 		return d
 	}
+
 	vh := hashNew()
 	for _, val := range labelValues {
 		vh = hashAdd(vh, val)
@@ -198,8 +186,3 @@ func (d *Desc) String() string {
 		d.variableLabels,
 	)
 }
-
-func checkLabelName(l string) bool {
-	return labelNameRE.MatchString(l) &&
-		!strings.HasPrefix(l, reservedLabelPrefix)
-}

vendor/github.com/prometheus/client_golang/prometheus/desc_test.go

@@ -0,0 +1,17 @@
+package prometheus
+
+import (
+	"testing"
+)
+
+func TestNewDescInvalidLabelValues(t *testing.T) {
+	desc := NewDesc(
+		"sample_label",
+		"sample label",
+		nil,
+		Labels{"a": "\xFF"},
+	)
+	if desc.err == nil {
+		t.Errorf("NewDesc: expected error because: %s", desc.err)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/doc.go

@@ -17,7 +17,7 @@
 // Pushgateway (package push).
 //
 // All exported functions and methods are safe to be used concurrently unless
-//specified otherwise.
+// specified otherwise.
 //
 // A Basic Example
 //
@@ -26,6 +26,7 @@
 //    package main
 //
 //    import (
+//    	"log"
 //    	"net/http"
 //
 //    	"github.com/prometheus/client_golang/prometheus"
@@ -59,7 +60,7 @@
 //    	// The Handler function provides a default handler to expose metrics
 //    	// via an HTTP server. "/metrics" is the usual endpoint for that.
 //    	http.Handle("/metrics", promhttp.Handler())
-//    	http.ListenAndServe(":8080", nil)
+//    	log.Fatal(http.ListenAndServe(":8080", nil))
 //    }
 //
 //
@@ -69,7 +70,7 @@
 // Metrics
 //
 // The number of exported identifiers in this package might appear a bit
-// overwhelming. Hovever, in addition to the basic plumbing shown in the example
+// overwhelming. However, in addition to the basic plumbing shown in the example
 // above, you only need to understand the different metric types and their
 // vector versions for basic usage.
 //
@@ -95,8 +96,8 @@
 // SummaryVec, HistogramVec, and UntypedVec are not.
 //
 // To create instances of Metrics and their vector versions, you need a suitable
-// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts,
-// HistogramOpts, or UntypedOpts.
+// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, HistogramOpts, or
+// UntypedOpts.
 //
 // Custom Collectors and constant Metrics
 //
@@ -114,8 +115,8 @@
 // Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
 // NewConstSummary (and their respective Must… versions). That will happen in
 // the Collect method. The Describe method has to return separate Desc
-// instances, representative of the “throw-away” metrics to be created
-// later. NewDesc comes in handy to create those Desc instances.
+// instances, representative of the “throw-away” metrics to be created later.
+// NewDesc comes in handy to create those Desc instances.
 //
 // The Collector example illustrates the use case. You can also look at the
 // source code of the processCollector (mirroring process metrics), the
@@ -129,34 +130,34 @@
 // Advanced Uses of the Registry
 //
 // While MustRegister is the by far most common way of registering a Collector,
-// sometimes you might want to handle the errors the registration might
-// cause. As suggested by the name, MustRegister panics if an error occurs. With
-// the Register function, the error is returned and can be handled.
+// sometimes you might want to handle the errors the registration might cause.
+// As suggested by the name, MustRegister panics if an error occurs. With the
+// Register function, the error is returned and can be handled.
 //
 // An error is returned if the registered Collector is incompatible or
 // inconsistent with already registered metrics. The registry aims for
-// consistency of the collected metrics according to the Prometheus data
-// model. Inconsistencies are ideally detected at registration time, not at
-// collect time. The former will usually be detected at start-up time of a
-// program, while the latter will only happen at scrape time, possibly not even
-// on the first scrape if the inconsistency only becomes relevant later. That is
-// the main reason why a Collector and a Metric have to describe themselves to
-// the registry.
+// consistency of the collected metrics according to the Prometheus data model.
+// Inconsistencies are ideally detected at registration time, not at collect
+// time. The former will usually be detected at start-up time of a program,
+// while the latter will only happen at scrape time, possibly not even on the
+// first scrape if the inconsistency only becomes relevant later. That is the
+// main reason why a Collector and a Metric have to describe themselves to the
+// registry.
 //
 // So far, everything we did operated on the so-called default registry, as it
-// can be found in the global DefaultRegistry variable. With NewRegistry, you
+// can be found in the global DefaultRegisterer variable. With NewRegistry, you
 // can create a custom registry, or you can even implement the Registerer or
-// Gatherer interfaces yourself. The methods Register and Unregister work in
-// the same way on a custom registry as the global functions Register and
-// Unregister on the default registry.
+// Gatherer interfaces yourself. The methods Register and Unregister work in the
+// same way on a custom registry as the global functions Register and Unregister
+// on the default registry.
 //
-// There are a number of uses for custom registries: You can use registries
-// with special properties, see NewPedanticRegistry. You can avoid global state,
-// as it is imposed by the DefaultRegistry. You can use multiple registries at
-// the same time to expose different metrics in different ways. You can use
+// There are a number of uses for custom registries: You can use registries with
+// special properties, see NewPedanticRegistry. You can avoid global state, as
+// it is imposed by the DefaultRegisterer. You can use multiple registries at
+// the same time to expose different metrics in different ways.  You can use
 // separate registries for testing purposes.
 //
-// Also note that the DefaultRegistry comes registered with a Collector for Go
+// Also note that the DefaultRegisterer comes registered with a Collector for Go
 // runtime metrics (via NewGoCollector) and a Collector for process metrics (via
 // NewProcessCollector). With a custom registry, you are in control and decide
 // yourself about the Collectors to register.
@@ -166,16 +167,20 @@
 // The Registry implements the Gatherer interface. The caller of the Gather
 // method can then expose the gathered metrics in some way. Usually, the metrics
 // are served via HTTP on the /metrics endpoint. That's happening in the example
-// above. The tools to expose metrics via HTTP are in the promhttp
-// sub-package. (The top-level functions in the prometheus package are
-// deprecated.)
+// above. The tools to expose metrics via HTTP are in the promhttp sub-package.
+// (The top-level functions in the prometheus package are deprecated.)
 //
 // Pushing to the Pushgateway
 //
 // Function for pushing to the Pushgateway can be found in the push sub-package.
 //
+// Graphite Bridge
+//
+// Functions and examples to push metrics from a Gatherer to Graphite can be
+// found in the graphite sub-package.
+//
 // Other Means of Exposition
 //
-// More ways of exposing metrics can easily be added. Sending metrics to
-// Graphite would be an example that will soon be implemented.
+// More ways of exposing metrics can easily be added by following the approaches
+// of the existing implementations.
 package prometheus

vendor/github.com/prometheus/client_golang/prometheus/example_timer_complex_test.go

@@ -0,0 +1,71 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus_test
+
+import (
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	// apiRequestDuration tracks the duration separate for each HTTP status
+	// class (1xx, 2xx, ...). This creates a fair amount of time series on
+	// the Prometheus server. Usually, you would track the duration of
+	// serving HTTP request without partitioning by outcome. Do something
+	// like this only if needed. Also note how only status classes are
+	// tracked, not every single status code. The latter would create an
+	// even larger amount of time series. Request counters partitioned by
+	// status code are usually OK as each counter only creates one time
+	// series. Histograms are way more expensive, so partition with care and
+	// only where you really need separate latency tracking. Partitioning by
+	// status class is only an example. In concrete cases, other partitions
+	// might make more sense.
+	apiRequestDuration = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "api_request_duration_seconds",
+			Help:    "Histogram for the request duration of the public API, partitioned by status class.",
+			Buckets: prometheus.ExponentialBuckets(0.1, 1.5, 5),
+		},
+		[]string{"status_class"},
+	)
+)
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	status := http.StatusOK
+	// The ObserverFunc gets called by the deferred ObserveDuration and
+	// decides which Histogram's Observe method is called.
+	timer := prometheus.NewTimer(prometheus.ObserverFunc(func(v float64) {
+		switch {
+		case status >= 500: // Server error.
+			apiRequestDuration.WithLabelValues("5xx").Observe(v)
+		case status >= 400: // Client error.
+			apiRequestDuration.WithLabelValues("4xx").Observe(v)
+		case status >= 300: // Redirection.
+			apiRequestDuration.WithLabelValues("3xx").Observe(v)
+		case status >= 200: // Success.
+			apiRequestDuration.WithLabelValues("2xx").Observe(v)
+		default: // Informational.
+			apiRequestDuration.WithLabelValues("1xx").Observe(v)
+		}
+	}))
+	defer timer.ObserveDuration()
+
+	// Handle the request. Set status accordingly.
+	// ...
+}
+
+func ExampleTimer_complex() {
+	http.HandleFunc("/api", handler)
+}

vendor/github.com/prometheus/client_golang/prometheus/example_timer_gauge_test.go

@@ -0,0 +1,48 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus_test
+
+import (
+	"os"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	// If a function is called rarely (i.e. not more often than scrapes
+	// happen) or ideally only once (like in a batch job), it can make sense
+	// to use a Gauge for timing the function call. For timing a batch job
+	// and pushing the result to a Pushgateway, see also the comprehensive
+	// example in the push package.
+	funcDuration = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "example_function_duration_seconds",
+		Help: "Duration of the last call of an example function.",
+	})
+)
+
+func run() error {
+	// The Set method of the Gauge is used to observe the duration.
+	timer := prometheus.NewTimer(prometheus.ObserverFunc(funcDuration.Set))
+	defer timer.ObserveDuration()
+
+	// Do something. Return errors as encountered. The use of 'defer' above
+	// makes sure the function is still timed properly.
+	return nil
+}
+
+func ExampleTimer_gauge() {
+	if err := run(); err != nil {
+		os.Exit(1)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/example_timer_test.go

@@ -0,0 +1,40 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus_test
+
+import (
+	"math/rand"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	requestDuration = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Name:    "example_request_duration_seconds",
+		Help:    "Histogram for the runtime of a simple example function.",
+		Buckets: prometheus.LinearBuckets(0.01, 0.01, 10),
+	})
+)
+
+func ExampleTimer() {
+	// timer times this example function. It uses a Histogram, but a Summary
+	// would also work, as both implement Observer. Check out
+	// https://prometheus.io/docs/practices/histograms/ for differences.
+	timer := prometheus.NewTimer(requestDuration)
+	defer timer.ObserveDuration()
+
+	// Do something here that takes time.
+	time.Sleep(time.Duration(rand.NormFloat64()*10000+50000) * time.Microsecond)
+}

vendor/github.com/prometheus/client_golang/prometheus/examples_test.go

@@ -113,7 +113,7 @@ func ExampleCounter() {
 	pushComplete := make(chan struct{})
 	// TODO: Start a goroutine that performs repository pushes and reports
 	// each completion via the channel.
-	for _ = range pushComplete {
+	for range pushComplete {
 		pushCounter.Inc()
 	}
 	// Output:
@@ -169,8 +169,8 @@ func ExampleInstrumentHandler() {
 
 func ExampleLabelPairSorter() {
 	labelPairs := []*dto.LabelPair{
-		&dto.LabelPair{Name: proto.String("status"), Value: proto.String("404")},
-		&dto.LabelPair{Name: proto.String("method"), Value: proto.String("get")},
+		{Name: proto.String("status"), Value: proto.String("404")},
+		{Name: proto.String("method"), Value: proto.String("get")},
 	}
 
 	sort.Sort(prometheus.LabelPairSorter(labelPairs))
@@ -334,8 +334,9 @@ func ExampleRegister() {
 
 func ExampleSummary() {
 	temps := prometheus.NewSummary(prometheus.SummaryOpts{
-		Name: "pond_temperature_celsius",
-		Help: "The temperature of the frog pond.", // Sorry, we can't measure how badly it smells.
+		Name:       "pond_temperature_celsius",
+		Help:       "The temperature of the frog pond.",
+		Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 	})
 
 	// Simulate some observations.
@@ -372,8 +373,9 @@ func ExampleSummary() {
 func ExampleSummaryVec() {
 	temps := prometheus.NewSummaryVec(
 		prometheus.SummaryOpts{
-			Name: "pond_temperature_celsius",
-			Help: "The temperature of the frog pond.", // Sorry, we can't measure how badly it smells.
+			Name:       "pond_temperature_celsius",
+			Help:       "The temperature of the frog pond.",
+			Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 		},
 		[]string{"species"},
 	)
@@ -640,6 +642,7 @@ func ExampleAlreadyRegisteredError() {
 			panic(err)
 		}
 	}
+	reqCounter.Inc()
 }
 
 func ExampleGatherers() {

vendor/github.com/prometheus/client_golang/prometheus/expvar_collector_test.go

@@ -24,7 +24,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
-func ExampleExpvarCollector() {
+func ExampleNewExpvarCollector() {
 	expvarCollector := prometheus.NewExpvarCollector(map[string]*prometheus.Desc{
 		"memstats": prometheus.NewDesc(
 			"expvar_memstats",

vendor/github.com/prometheus/client_golang/prometheus/gauge.go

@@ -13,6 +13,14 @@
 
 package prometheus
 
+import (
+	"math"
+	"sync/atomic"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
 // Gauge is a Metric that represents a single numerical value that can
 // arbitrarily go up and down.
 //
@@ -27,29 +35,95 @@ type Gauge interface {
 
 	// Set sets the Gauge to an arbitrary value.
 	Set(float64)
-	// Inc increments the Gauge by 1.
+	// Inc increments the Gauge by 1. Use Add to increment it by arbitrary
+	// values.
 	Inc()
-	// Dec decrements the Gauge by 1.
+	// Dec decrements the Gauge by 1. Use Sub to decrement it by arbitrary
+	// values.
 	Dec()
-	// Add adds the given value to the Gauge. (The value can be
-	// negative, resulting in a decrease of the Gauge.)
+	// Add adds the given value to the Gauge. (The value can be negative,
+	// resulting in a decrease of the Gauge.)
 	Add(float64)
 	// Sub subtracts the given value from the Gauge. (The value can be
 	// negative, resulting in an increase of the Gauge.)
 	Sub(float64)
+
+	// SetToCurrentTime sets the Gauge to the current Unix time in seconds.
+	SetToCurrentTime()
 }
 
 // GaugeOpts is an alias for Opts. See there for doc comments.
 type GaugeOpts Opts
 
 // NewGauge creates a new Gauge based on the provided GaugeOpts.
+//
+// The returned implementation is optimized for a fast Set method. If you have a
+// choice for managing the value of a Gauge via Set vs. Inc/Dec/Add/Sub, pick
+// the former. For example, the Inc method of the returned Gauge is slower than
+// the Inc method of a Counter returned by NewCounter. This matches the typical
+// scenarios for Gauges and Counters, where the former tends to be Set-heavy and
+// the latter Inc-heavy.
 func NewGauge(opts GaugeOpts) Gauge {
-	return newValue(NewDesc(
+	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
 		opts.Help,
 		nil,
 		opts.ConstLabels,
-	), GaugeValue, 0)
+	)
+	result := &gauge{desc: desc, labelPairs: desc.constLabelPairs}
+	result.init(result) // Init self-collection.
+	return result
+}
+
+type gauge struct {
+	// valBits contains the bits of the represented float64 value. It has
+	// to go first in the struct to guarantee alignment for atomic
+	// operations.  http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+
+	selfCollector
+
+	desc       *Desc
+	labelPairs []*dto.LabelPair
+}
+
+func (g *gauge) Desc() *Desc {
+	return g.desc
+}
+
+func (g *gauge) Set(val float64) {
+	atomic.StoreUint64(&g.valBits, math.Float64bits(val))
+}
+
+func (g *gauge) SetToCurrentTime() {
+	g.Set(float64(time.Now().UnixNano()) / 1e9)
+}
+
+func (g *gauge) Inc() {
+	g.Add(1)
+}
+
+func (g *gauge) Dec() {
+	g.Add(-1)
+}
+
+func (g *gauge) Add(val float64) {
+	for {
+		oldBits := atomic.LoadUint64(&g.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
+		if atomic.CompareAndSwapUint64(&g.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (g *gauge) Sub(val float64) {
+	g.Add(val * -1)
+}
+
+func (g *gauge) Write(out *dto.Metric) error {
+	val := math.Float64frombits(atomic.LoadUint64(&g.valBits))
+	return populateMetric(GaugeValue, val, g.labelPairs, out)
 }
 
 // GaugeVec is a Collector that bundles a set of Gauges that all share the same
@@ -58,12 +132,11 @@ func NewGauge(opts GaugeOpts) Gauge {
 // (e.g. number of operations queued, partitioned by user and operation
 // type). Create instances with NewGaugeVec.
 type GaugeVec struct {
-	*MetricVec
+	*metricVec
 }
 
 // NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
+// partitioned by the given label names.
 func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
@@ -72,28 +145,62 @@ func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
 		opts.ConstLabels,
 	)
 	return &GaugeVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
-			return newValue(desc, GaugeValue, 0, lvs...)
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels) {
+				panic(errInconsistentCardinality)
+			}
+			result := &gauge{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
+			result.init(result) // Init self-collection.
+			return result
 		}),
 	}
 }
 
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns a Gauge and not a
-// Metric so that no type conversion is required.
-func (m *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+// GetMetricWithLabelValues returns the Gauge for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Gauge is created.
+//
+// It is possible to call this method without using the returned Gauge to only
+// create the new Gauge but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Gauge for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Gauge from the GaugeVec. In that case, the
+// Gauge will still exist, but it will not be exported anymore, even if a
+// Gauge with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+func (v *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
 	if metric != nil {
 		return metric.(Gauge), err
 	}
 	return nil, err
 }
 
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns a Gauge and not a Metric so that no
-// type conversion is required.
-func (m *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
+// GetMetricWith returns the Gauge for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Gauge is created. Implications of
+// creating a Gauge without using it and keeping the Gauge for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
 	if metric != nil {
 		return metric.(Gauge), err
 	}
@@ -101,18 +208,57 @@ func (m *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
 }
 
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
 //     myVec.WithLabelValues("404", "GET").Add(42)
-func (m *GaugeVec) WithLabelValues(lvs ...string) Gauge {
-	return m.MetricVec.WithLabelValues(lvs...).(Gauge)
+func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
+	g, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return g
 }
 
 // With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
-func (m *GaugeVec) With(labels Labels) Gauge {
-	return m.MetricVec.With(labels).(Gauge)
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *GaugeVec) With(labels Labels) Gauge {
+	g, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the GaugeVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *GaugeVec) CurryWith(labels Labels) (*GaugeVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &GaugeVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *GaugeVec) MustCurryWith(labels Labels) *GaugeVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
 }
 
 // GaugeFunc is a Gauge whose value is determined at collect time by calling a

vendor/github.com/prometheus/client_golang/prometheus/gauge_test.go

@@ -19,6 +19,7 @@ import (
 	"sync"
 	"testing"
 	"testing/quick"
+	"time"
 
 	dto "github.com/prometheus/client_model/go"
 )
@@ -82,7 +83,7 @@ func TestGaugeConcurrency(t *testing.T) {
 		}
 		start.Done()
 
-		if expected, got := <-result, math.Float64frombits(gge.(*value).valBits); math.Abs(expected-got) > 0.000001 {
+		if expected, got := <-result, math.Float64frombits(gge.(*gauge).valBits); math.Abs(expected-got) > 0.000001 {
 			t.Fatalf("expected approx. %f, got %f", expected, got)
 			return false
 		}
@@ -146,7 +147,7 @@ func TestGaugeVecConcurrency(t *testing.T) {
 		start.Done()
 
 		for i := range sStreams {
-			if expected, got := <-results[i], math.Float64frombits(gge.WithLabelValues(string('A'+i)).(*value).valBits); math.Abs(expected-got) > 0.000001 {
+			if expected, got := <-results[i], math.Float64frombits(gge.WithLabelValues(string('A'+i)).(*gauge).valBits); math.Abs(expected-got) > 0.000001 {
 				t.Fatalf("expected approx. %f, got %f", expected, got)
 				return false
 			}
@@ -180,3 +181,22 @@ func TestGaugeFunc(t *testing.T) {
 		t.Errorf("expected %q, got %q", expected, got)
 	}
 }
+
+func TestGaugeSetCurrentTime(t *testing.T) {
+	g := NewGauge(GaugeOpts{
+		Name: "test_name",
+		Help: "test help",
+	})
+	g.SetToCurrentTime()
+	unixTime := float64(time.Now().Unix())
+
+	m := &dto.Metric{}
+	g.Write(m)
+
+	delta := unixTime - m.GetGauge().GetValue()
+	// This is just a smoke test to make sure SetToCurrentTime is not
+	// totally off. Tests with current time involved are hard...
+	if math.Abs(delta) > 5 {
+		t.Errorf("Gauge set to current time deviates from current time by more than 5s, delta is %f seconds", delta)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/go_collector.go

@@ -8,8 +8,10 @@ import (
 )
 
 type goCollector struct {
-	goroutines Gauge
-	gcDesc     *Desc
+	goroutinesDesc *Desc
+	threadsDesc    *Desc
+	gcDesc         *Desc
+	goInfoDesc     *Desc
 
 	// metrics to describe and collect
 	metrics memStatsMetrics
@@ -19,15 +21,22 @@ type goCollector struct {
 // go process.
 func NewGoCollector() Collector {
 	return &goCollector{
-		goroutines: NewGauge(GaugeOpts{
-			Namespace: "go",
-			Name:      "goroutines",
-			Help:      "Number of goroutines that currently exist.",
-		}),
+		goroutinesDesc: NewDesc(
+			"go_goroutines",
+			"Number of goroutines that currently exist.",
+			nil, nil),
+		threadsDesc: NewDesc(
+			"go_threads",
+			"Number of OS threads created.",
+			nil, nil),
 		gcDesc: NewDesc(
 			"go_gc_duration_seconds",
 			"A summary of the GC invocation durations.",
 			nil, nil),
+		goInfoDesc: NewDesc(
+			"go_info",
+			"Information about the Go environment.",
+			nil, Labels{"version": runtime.Version()}),
 		metrics: memStatsMetrics{
 			{
 				desc: NewDesc(
@@ -48,7 +57,7 @@ func NewGoCollector() Collector {
 			}, {
 				desc: NewDesc(
 					memstatNamespace("sys_bytes"),
-					"Number of bytes obtained by system. Sum of all system allocations.",
+					"Number of bytes obtained from system.",
 					nil, nil,
 				),
 				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
@@ -111,12 +120,12 @@ func NewGoCollector() Collector {
 				valType: GaugeValue,
 			}, {
 				desc: NewDesc(
-					memstatNamespace("heap_released_bytes_total"),
-					"Total number of heap bytes released to OS.",
+					memstatNamespace("heap_released_bytes"),
+					"Number of heap bytes released to OS.",
 					nil, nil,
 				),
 				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
-				valType: CounterValue,
+				valType: GaugeValue,
 			}, {
 				desc: NewDesc(
 					memstatNamespace("heap_objects"),
@@ -213,6 +222,14 @@ func NewGoCollector() Collector {
 				),
 				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.LastGC) / 1e9 },
 				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("gc_cpu_fraction"),
+					"The fraction of this program's available CPU time used by the GC since the program started.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return ms.GCCPUFraction },
+				valType: GaugeValue,
 			},
 		},
 	}
@@ -224,9 +241,10 @@ func memstatNamespace(s string) string {
 
 // Describe returns all descriptions of the collector.
 func (c *goCollector) Describe(ch chan<- *Desc) {
-	ch <- c.goroutines.Desc()
+	ch <- c.goroutinesDesc
+	ch <- c.threadsDesc
 	ch <- c.gcDesc
-
+	ch <- c.goInfoDesc
 	for _, i := range c.metrics {
 		ch <- i.desc
 	}
@@ -234,8 +252,9 @@ func (c *goCollector) Describe(ch chan<- *Desc) {
 
 // Collect returns the current state of all metrics of the collector.
 func (c *goCollector) Collect(ch chan<- Metric) {
-	c.goroutines.Set(float64(runtime.NumGoroutine()))
-	ch <- c.goroutines
+	ch <- MustNewConstMetric(c.goroutinesDesc, GaugeValue, float64(runtime.NumGoroutine()))
+	n, _ := runtime.ThreadCreateProfile(nil)
+	ch <- MustNewConstMetric(c.threadsDesc, GaugeValue, float64(n))
 
 	var stats debug.GCStats
 	stats.PauseQuantiles = make([]time.Duration, 5)
@@ -248,6 +267,8 @@ func (c *goCollector) Collect(ch chan<- Metric) {
 	quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
 	ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), float64(stats.PauseTotal.Seconds()), quantiles)
 
+	ch <- MustNewConstMetric(c.goInfoDesc, GaugeValue, 1)
+
 	ms := &runtime.MemStats{}
 	runtime.ReadMemStats(ms)
 	for _, i := range c.metrics {

vendor/github.com/prometheus/client_golang/prometheus/go_collector_test.go

@@ -29,33 +29,37 @@ func TestGoCollector(t *testing.T) {
 
 	for {
 		select {
-		case metric := <-ch:
-			switch m := metric.(type) {
-			// Attention, this also catches Counter...
-			case Gauge:
-				pb := &dto.Metric{}
-				m.Write(pb)
-				if pb.GetGauge() == nil {
-					continue
-				}
-
-				if old == -1 {
-					old = int(pb.GetGauge().GetValue())
-					close(waitc)
-					continue
-				}
-
-				if diff := int(pb.GetGauge().GetValue()) - old; diff != 1 {
-					// TODO: This is flaky in highly concurrent situations.
-					t.Errorf("want 1 new goroutine, got %d", diff)
-				}
-
-				// GoCollector performs two sends per call.
-				// On line 27 we need to receive the second send
-				// to shut down cleanly.
-				<-ch
-				return
+		case m := <-ch:
+			// m can be Gauge or Counter,
+			// currently just test the go_goroutines Gauge
+			// and ignore others.
+			if m.Desc().fqName != "go_goroutines" {
+				continue
 			}
+			pb := &dto.Metric{}
+			m.Write(pb)
+			if pb.GetGauge() == nil {
+				continue
+			}
+
+			if old == -1 {
+				old = int(pb.GetGauge().GetValue())
+				close(waitc)
+				continue
+			}
+
+			if diff := int(pb.GetGauge().GetValue()) - old; diff != 1 {
+				// TODO: This is flaky in highly concurrent situations.
+				t.Errorf("want 1 new goroutine, got %d", diff)
+			}
+
+			// GoCollector performs three sends per call.
+			// On line 27 we need to receive three more sends
+			// to shut down cleanly.
+			<-ch
+			<-ch
+			<-ch
+			return
 		case <-time.After(1 * time.Second):
 			t.Fatalf("expected collect timed out")
 		}
@@ -85,37 +89,33 @@ func TestGCCollector(t *testing.T) {
 	for {
 		select {
 		case metric := <-ch:
-			switch m := metric.(type) {
-			case *constSummary, *value:
-				pb := &dto.Metric{}
-				m.Write(pb)
-				if pb.GetSummary() == nil {
-					continue
-				}
-
-				if len(pb.GetSummary().Quantile) != 5 {
-					t.Errorf("expected 4 buckets, got %d", len(pb.GetSummary().Quantile))
-				}
-				for idx, want := range []float64{0.0, 0.25, 0.5, 0.75, 1.0} {
-					if *pb.GetSummary().Quantile[idx].Quantile != want {
-						t.Errorf("bucket #%d is off, got %f, want %f", idx, *pb.GetSummary().Quantile[idx].Quantile, want)
-					}
-				}
-				if first {
-					first = false
-					oldGC = *pb.GetSummary().SampleCount
-					oldPause = *pb.GetSummary().SampleSum
-					close(waitc)
-					continue
-				}
-				if diff := *pb.GetSummary().SampleCount - oldGC; diff != 1 {
-					t.Errorf("want 1 new garbage collection run, got %d", diff)
-				}
-				if diff := *pb.GetSummary().SampleSum - oldPause; diff <= 0 {
-					t.Errorf("want moar pause, got %f", diff)
-				}
-				return
+			pb := &dto.Metric{}
+			metric.Write(pb)
+			if pb.GetSummary() == nil {
+				continue
 			}
+			if len(pb.GetSummary().Quantile) != 5 {
+				t.Errorf("expected 4 buckets, got %d", len(pb.GetSummary().Quantile))
+			}
+			for idx, want := range []float64{0.0, 0.25, 0.5, 0.75, 1.0} {
+				if *pb.GetSummary().Quantile[idx].Quantile != want {
+					t.Errorf("bucket #%d is off, got %f, want %f", idx, *pb.GetSummary().Quantile[idx].Quantile, want)
+				}
+			}
+			if first {
+				first = false
+				oldGC = *pb.GetSummary().SampleCount
+				oldPause = *pb.GetSummary().SampleSum
+				close(waitc)
+				continue
+			}
+			if diff := *pb.GetSummary().SampleCount - oldGC; diff != 1 {
+				t.Errorf("want 1 new garbage collection run, got %d", diff)
+			}
+			if diff := *pb.GetSummary().SampleSum - oldPause; diff <= 0 {
+				t.Errorf("want moar pause, got %f", diff)
+			}
+			return
 		case <-time.After(1 * time.Second):
 			t.Fatalf("expected collect timed out")
 		}

vendor/github.com/prometheus/client_golang/prometheus/graphite/bridge.go

@@ -0,0 +1,280 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package graphite provides a bridge to push Prometheus metrics to a Graphite
+// server.
+package graphite
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"sort"
+	"time"
+
+	"github.com/prometheus/common/expfmt"
+	"github.com/prometheus/common/model"
+	"golang.org/x/net/context"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	defaultInterval       = 15 * time.Second
+	millisecondsPerSecond = 1000
+)
+
+// HandlerErrorHandling defines how a Handler serving metrics will handle
+// errors.
+type HandlerErrorHandling int
+
+// These constants cause handlers serving metrics to behave as described if
+// errors are encountered.
+const (
+	// Ignore errors and try to push as many metrics to Graphite as possible.
+	ContinueOnError HandlerErrorHandling = iota
+
+	// Abort the push to Graphite upon the first error encountered.
+	AbortOnError
+)
+
+// Config defines the Graphite bridge config.
+type Config struct {
+	// The url to push data to. Required.
+	URL string
+
+	// The prefix for the pushed Graphite metrics. Defaults to empty string.
+	Prefix string
+
+	// The interval to use for pushing data to Graphite. Defaults to 15 seconds.
+	Interval time.Duration
+
+	// The timeout for pushing metrics to Graphite. Defaults to 15 seconds.
+	Timeout time.Duration
+
+	// The Gatherer to use for metrics. Defaults to prometheus.DefaultGatherer.
+	Gatherer prometheus.Gatherer
+
+	// The logger that messages are written to. Defaults to no logging.
+	Logger Logger
+
+	// ErrorHandling defines how errors are handled. Note that errors are
+	// logged regardless of the configured ErrorHandling provided Logger
+	// is not nil.
+	ErrorHandling HandlerErrorHandling
+}
+
+// Bridge pushes metrics to the configured Graphite server.
+type Bridge struct {
+	url      string
+	prefix   string
+	interval time.Duration
+	timeout  time.Duration
+
+	errorHandling HandlerErrorHandling
+	logger        Logger
+
+	g prometheus.Gatherer
+}
+
+// Logger is the minimal interface Bridge needs for logging. Note that
+// log.Logger from the standard library implements this interface, and it is
+// easy to implement by custom loggers, if they don't do so already anyway.
+type Logger interface {
+	Println(v ...interface{})
+}
+
+// NewBridge returns a pointer to a new Bridge struct.
+func NewBridge(c *Config) (*Bridge, error) {
+	b := &Bridge{}
+
+	if c.URL == "" {
+		return nil, errors.New("missing URL")
+	}
+	b.url = c.URL
+
+	if c.Gatherer == nil {
+		b.g = prometheus.DefaultGatherer
+	} else {
+		b.g = c.Gatherer
+	}
+
+	if c.Logger != nil {
+		b.logger = c.Logger
+	}
+
+	if c.Prefix != "" {
+		b.prefix = c.Prefix
+	}
+
+	var z time.Duration
+	if c.Interval == z {
+		b.interval = defaultInterval
+	} else {
+		b.interval = c.Interval
+	}
+
+	if c.Timeout == z {
+		b.timeout = defaultInterval
+	} else {
+		b.timeout = c.Timeout
+	}
+
+	b.errorHandling = c.ErrorHandling
+
+	return b, nil
+}
+
+// Run starts the event loop that pushes Prometheus metrics to Graphite at the
+// configured interval.
+func (b *Bridge) Run(ctx context.Context) {
+	ticker := time.NewTicker(b.interval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			if err := b.Push(); err != nil && b.logger != nil {
+				b.logger.Println("error pushing to Graphite:", err)
+			}
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
+// Push pushes Prometheus metrics to the configured Graphite server.
+func (b *Bridge) Push() error {
+	mfs, err := b.g.Gather()
+	if err != nil || len(mfs) == 0 {
+		switch b.errorHandling {
+		case AbortOnError:
+			return err
+		case ContinueOnError:
+			if b.logger != nil {
+				b.logger.Println("continue on error:", err)
+			}
+		default:
+			panic("unrecognized error handling value")
+		}
+	}
+
+	conn, err := net.DialTimeout("tcp", b.url, b.timeout)
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	return writeMetrics(conn, mfs, b.prefix, model.Now())
+}
+
+func writeMetrics(w io.Writer, mfs []*dto.MetricFamily, prefix string, now model.Time) error {
+	vec, err := expfmt.ExtractSamples(&expfmt.DecodeOptions{
+		Timestamp: now,
+	}, mfs...)
+	if err != nil {
+		return err
+	}
+
+	buf := bufio.NewWriter(w)
+	for _, s := range vec {
+		if err := writeSanitized(buf, prefix); err != nil {
+			return err
+		}
+		if err := buf.WriteByte('.'); err != nil {
+			return err
+		}
+		if err := writeMetric(buf, s.Metric); err != nil {
+			return err
+		}
+		if _, err := fmt.Fprintf(buf, " %g %d\n", s.Value, int64(s.Timestamp)/millisecondsPerSecond); err != nil {
+			return err
+		}
+		if err := buf.Flush(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func writeMetric(buf *bufio.Writer, m model.Metric) error {
+	metricName, hasName := m[model.MetricNameLabel]
+	numLabels := len(m) - 1
+	if !hasName {
+		numLabels = len(m)
+	}
+
+	labelStrings := make([]string, 0, numLabels)
+	for label, value := range m {
+		if label != model.MetricNameLabel {
+			labelStrings = append(labelStrings, fmt.Sprintf("%s %s", string(label), string(value)))
+		}
+	}
+
+	var err error
+	switch numLabels {
+	case 0:
+		if hasName {
+			return writeSanitized(buf, string(metricName))
+		}
+	default:
+		sort.Strings(labelStrings)
+		if err = writeSanitized(buf, string(metricName)); err != nil {
+			return err
+		}
+		for _, s := range labelStrings {
+			if err = buf.WriteByte('.'); err != nil {
+				return err
+			}
+			if err = writeSanitized(buf, s); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func writeSanitized(buf *bufio.Writer, s string) error {
+	prevUnderscore := false
+
+	for _, c := range s {
+		c = replaceInvalidRune(c)
+		if c == '_' {
+			if prevUnderscore {
+				continue
+			}
+			prevUnderscore = true
+		} else {
+			prevUnderscore = false
+		}
+		if _, err := buf.WriteRune(c); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func replaceInvalidRune(c rune) rune {
+	if c == ' ' {
+		return '.'
+	}
+	if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_' || c == ':' || (c >= '0' && c <= '9')) {
+		return '_'
+	}
+	return c
+}

vendor/github.com/prometheus/client_golang/prometheus/graphite/bridge_test.go

@@ -0,0 +1,309 @@
+package graphite
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"log"
+	"net"
+	"os"
+	"regexp"
+	"testing"
+	"time"
+
+	"github.com/prometheus/common/model"
+	"golang.org/x/net/context"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+func TestSanitize(t *testing.T) {
+	testCases := []struct {
+		in, out string
+	}{
+		{in: "hello", out: "hello"},
+		{in: "hE/l1o", out: "hE_l1o"},
+		{in: "he,*ll(.o", out: "he_ll_o"},
+		{in: "hello_there%^&", out: "hello_there_"},
+	}
+
+	var buf bytes.Buffer
+	w := bufio.NewWriter(&buf)
+
+	for i, tc := range testCases {
+		if err := writeSanitized(w, tc.in); err != nil {
+			t.Fatalf("write failed: %v", err)
+		}
+		if err := w.Flush(); err != nil {
+			t.Fatalf("flush failed: %v", err)
+		}
+
+		if want, got := tc.out, buf.String(); want != got {
+			t.Fatalf("test case index %d: got sanitized string %s, want %s", i, got, want)
+		}
+
+		buf.Reset()
+	}
+}
+
+func TestWriteSummary(t *testing.T) {
+	sumVec := prometheus.NewSummaryVec(
+		prometheus.SummaryOpts{
+			Name:        "name",
+			Help:        "docstring",
+			ConstLabels: prometheus.Labels{"constname": "constvalue"},
+			Objectives:  map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
+		},
+		[]string{"labelname"},
+	)
+
+	sumVec.WithLabelValues("val1").Observe(float64(10))
+	sumVec.WithLabelValues("val1").Observe(float64(20))
+	sumVec.WithLabelValues("val1").Observe(float64(30))
+	sumVec.WithLabelValues("val2").Observe(float64(20))
+	sumVec.WithLabelValues("val2").Observe(float64(30))
+	sumVec.WithLabelValues("val2").Observe(float64(40))
+
+	reg := prometheus.NewRegistry()
+	reg.MustRegister(sumVec)
+
+	mfs, err := reg.Gather()
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+
+	now := model.Time(1477043083)
+	var buf bytes.Buffer
+	err = writeMetrics(&buf, mfs, "prefix", now)
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+
+	want := `prefix.name.constname.constvalue.labelname.val1.quantile.0_5 20 1477043
+prefix.name.constname.constvalue.labelname.val1.quantile.0_9 30 1477043
+prefix.name.constname.constvalue.labelname.val1.quantile.0_99 30 1477043
+prefix.name_sum.constname.constvalue.labelname.val1 60 1477043
+prefix.name_count.constname.constvalue.labelname.val1 3 1477043
+prefix.name.constname.constvalue.labelname.val2.quantile.0_5 30 1477043
+prefix.name.constname.constvalue.labelname.val2.quantile.0_9 40 1477043
+prefix.name.constname.constvalue.labelname.val2.quantile.0_99 40 1477043
+prefix.name_sum.constname.constvalue.labelname.val2 90 1477043
+prefix.name_count.constname.constvalue.labelname.val2 3 1477043
+`
+
+	if got := buf.String(); want != got {
+		t.Fatalf("wanted \n%s\n, got \n%s\n", want, got)
+	}
+}
+
+func TestWriteHistogram(t *testing.T) {
+	histVec := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:        "name",
+			Help:        "docstring",
+			ConstLabels: prometheus.Labels{"constname": "constvalue"},
+			Buckets:     []float64{0.01, 0.02, 0.05, 0.1},
+		},
+		[]string{"labelname"},
+	)
+
+	histVec.WithLabelValues("val1").Observe(float64(10))
+	histVec.WithLabelValues("val1").Observe(float64(20))
+	histVec.WithLabelValues("val1").Observe(float64(30))
+	histVec.WithLabelValues("val2").Observe(float64(20))
+	histVec.WithLabelValues("val2").Observe(float64(30))
+	histVec.WithLabelValues("val2").Observe(float64(40))
+
+	reg := prometheus.NewRegistry()
+	reg.MustRegister(histVec)
+
+	mfs, err := reg.Gather()
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+
+	now := model.Time(1477043083)
+	var buf bytes.Buffer
+	err = writeMetrics(&buf, mfs, "prefix", now)
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+
+	want := `prefix.name_bucket.constname.constvalue.labelname.val1.le.0_01 0 1477043
+prefix.name_bucket.constname.constvalue.labelname.val1.le.0_02 0 1477043
+prefix.name_bucket.constname.constvalue.labelname.val1.le.0_05 0 1477043
+prefix.name_bucket.constname.constvalue.labelname.val1.le.0_1 0 1477043
+prefix.name_sum.constname.constvalue.labelname.val1 60 1477043
+prefix.name_count.constname.constvalue.labelname.val1 3 1477043
+prefix.name_bucket.constname.constvalue.labelname.val1.le._Inf 3 1477043
+prefix.name_bucket.constname.constvalue.labelname.val2.le.0_01 0 1477043
+prefix.name_bucket.constname.constvalue.labelname.val2.le.0_02 0 1477043
+prefix.name_bucket.constname.constvalue.labelname.val2.le.0_05 0 1477043
+prefix.name_bucket.constname.constvalue.labelname.val2.le.0_1 0 1477043
+prefix.name_sum.constname.constvalue.labelname.val2 90 1477043
+prefix.name_count.constname.constvalue.labelname.val2 3 1477043
+prefix.name_bucket.constname.constvalue.labelname.val2.le._Inf 3 1477043
+`
+	if got := buf.String(); want != got {
+		t.Fatalf("wanted \n%s\n, got \n%s\n", want, got)
+	}
+}
+
+func TestToReader(t *testing.T) {
+	cntVec := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name:        "name",
+			Help:        "docstring",
+			ConstLabels: prometheus.Labels{"constname": "constvalue"},
+		},
+		[]string{"labelname"},
+	)
+	cntVec.WithLabelValues("val1").Inc()
+	cntVec.WithLabelValues("val2").Inc()
+
+	reg := prometheus.NewRegistry()
+	reg.MustRegister(cntVec)
+
+	want := `prefix.name.constname.constvalue.labelname.val1 1 1477043
+prefix.name.constname.constvalue.labelname.val2 1 1477043
+`
+	mfs, err := reg.Gather()
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+
+	now := model.Time(1477043083)
+	var buf bytes.Buffer
+	err = writeMetrics(&buf, mfs, "prefix", now)
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+
+	if got := buf.String(); want != got {
+		t.Fatalf("wanted \n%s\n, got \n%s\n", want, got)
+	}
+}
+
+func TestPush(t *testing.T) {
+	reg := prometheus.NewRegistry()
+	cntVec := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name:        "name",
+			Help:        "docstring",
+			ConstLabels: prometheus.Labels{"constname": "constvalue"},
+		},
+		[]string{"labelname"},
+	)
+	cntVec.WithLabelValues("val1").Inc()
+	cntVec.WithLabelValues("val2").Inc()
+	reg.MustRegister(cntVec)
+
+	host := "localhost"
+	port := ":56789"
+	b, err := NewBridge(&Config{
+		URL:      host + port,
+		Gatherer: reg,
+		Prefix:   "prefix",
+	})
+	if err != nil {
+		t.Fatalf("error creating bridge: %v", err)
+	}
+
+	nmg, err := newMockGraphite(port)
+	if err != nil {
+		t.Fatalf("error creating mock graphite: %v", err)
+	}
+	defer nmg.Close()
+
+	err = b.Push()
+	if err != nil {
+		t.Fatalf("error pushing: %v", err)
+	}
+
+	wants := []string{
+		"prefix.name.constname.constvalue.labelname.val1 1",
+		"prefix.name.constname.constvalue.labelname.val2 1",
+	}
+
+	select {
+	case got := <-nmg.readc:
+		for _, want := range wants {
+			matched, err := regexp.MatchString(want, got)
+			if err != nil {
+				t.Fatalf("error pushing: %v", err)
+			}
+			if !matched {
+				t.Fatalf("missing metric:\nno match for %s received by server:\n%s", want, got)
+			}
+		}
+		return
+	case err := <-nmg.errc:
+		t.Fatalf("error reading push: %v", err)
+	case <-time.After(50 * time.Millisecond):
+		t.Fatalf("no result from graphite server")
+	}
+}
+
+func newMockGraphite(port string) (*mockGraphite, error) {
+	readc := make(chan string)
+	errc := make(chan error)
+	ln, err := net.Listen("tcp", port)
+	if err != nil {
+		return nil, err
+	}
+
+	go func() {
+		conn, err := ln.Accept()
+		if err != nil {
+			errc <- err
+		}
+		var b bytes.Buffer
+		io.Copy(&b, conn)
+		readc <- b.String()
+	}()
+
+	return &mockGraphite{
+		readc:    readc,
+		errc:     errc,
+		Listener: ln,
+	}, nil
+}
+
+type mockGraphite struct {
+	readc chan string
+	errc  chan error
+
+	net.Listener
+}
+
+func ExampleBridge() {
+	b, err := NewBridge(&Config{
+		URL:           "graphite.example.org:3099",
+		Gatherer:      prometheus.DefaultGatherer,
+		Prefix:        "prefix",
+		Interval:      15 * time.Second,
+		Timeout:       10 * time.Second,
+		ErrorHandling: AbortOnError,
+		Logger:        log.New(os.Stdout, "graphite bridge: ", log.Lshortfile),
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	go func() {
+		// Start something in a goroutine that uses metrics.
+	}()
+
+	// Push initial metrics to Graphite. Fail fast if the push fails.
+	if err := b.Push(); err != nil {
+		panic(err)
+	}
+
+	// Create a Context to control stopping the Run() loop that pushes
+	// metrics to Graphite.
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// Start pushing metrics to Graphite in the Run() loop.
+	b.Run(ctx)
+}

vendor/github.com/prometheus/client_golang/prometheus/histogram.go

@@ -126,23 +126,16 @@ type HistogramOpts struct {
 	// string.
 	Help string
 
-	// ConstLabels are used to attach fixed labels to this
-	// Histogram. Histograms with the same fully-qualified name must have the
-	// same label names in their ConstLabels.
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
 	//
-	// Note that in most cases, labels have a value that varies during the
-	// lifetime of a process. Those labels are usually managed with a
-	// HistogramVec. ConstLabels serve only special purposes. One is for the
-	// special case where the value of a label does not change during the
-	// lifetime of a process, e.g. if the revision of the running binary is
-	// put into a label. Another, more advanced purpose is if more than one
-	// Collector needs to collect Histograms with the same fully-qualified
-	// name. In that case, those Summaries must differ in the values of
-	// their ConstLabels. See the Collector examples.
-	//
-	// If the value of a label never changes (not even between binaries),
-	// that label most likely should not be a label at all (but part of the
-	// metric name).
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
 	ConstLabels Labels
 
 	// Buckets defines the buckets into which observations are counted. Each
@@ -287,12 +280,11 @@ func (h *histogram) Write(out *dto.Metric) error {
 // (e.g. HTTP request latencies, partitioned by status code and method). Create
 // instances with NewHistogramVec.
 type HistogramVec struct {
-	*MetricVec
+	*metricVec
 }
 
 // NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
+// partitioned by the given label names.
 func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
@@ -301,47 +293,116 @@ func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
 		opts.ConstLabels,
 	)
 	return &HistogramVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
 			return newHistogram(desc, opts, lvs...)
 		}),
 	}
 }
 
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns a Histogram and not a
-// Metric so that no type conversion is required.
-func (m *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Histogram, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+// GetMetricWithLabelValues returns the Histogram for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Histogram is created.
+//
+// It is possible to call this method without using the returned Histogram to only
+// create the new Histogram but leave it at its starting value, a Histogram without
+// any observations.
+//
+// Keeping the Histogram for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Histogram from the HistogramVec. In that case, the
+// Histogram will still exist, but it will not be exported anymore, even if a
+// Histogram with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
 	if metric != nil {
-		return metric.(Histogram), err
+		return metric.(Observer), err
 	}
 	return nil, err
 }
 
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns a Histogram and not a Metric so that no
-// type conversion is required.
-func (m *HistogramVec) GetMetricWith(labels Labels) (Histogram, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
+// GetMetricWith returns the Histogram for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Histogram is created. Implications of
+// creating a Histogram without using it and keeping the Histogram for later use
+// are the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *HistogramVec) GetMetricWith(labels Labels) (Observer, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
 	if metric != nil {
-		return metric.(Histogram), err
+		return metric.(Observer), err
 	}
 	return nil, err
 }
 
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
 //     myVec.WithLabelValues("404", "GET").Observe(42.21)
-func (m *HistogramVec) WithLabelValues(lvs ...string) Histogram {
-	return m.MetricVec.WithLabelValues(lvs...).(Histogram)
+func (v *HistogramVec) WithLabelValues(lvs ...string) Observer {
+	h, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return h
 }
 
-// With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21)
-func (m *HistogramVec) With(labels Labels) Histogram {
-	return m.MetricVec.With(labels).(Histogram)
+// With works as GetMetricWith but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
+func (v *HistogramVec) With(labels Labels) Observer {
+	h, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return h
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the HistogramVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *HistogramVec) CurryWith(labels Labels) (ObserverVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &HistogramVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *HistogramVec) MustCurryWith(labels Labels) ObserverVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
 }
 
 type constHistogram struct {
@@ -401,8 +462,8 @@ func NewConstHistogram(
 	buckets map[float64]uint64,
 	labelValues ...string,
 ) (Metric, error) {
-	if len(desc.variableLabels) != len(labelValues) {
-		return nil, errInconsistentCardinality
+	if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
+		return nil, err
 	}
 	return &constHistogram{
 		desc:       desc,

vendor/github.com/prometheus/client_golang/prometheus/histogram_test.go

@@ -119,6 +119,28 @@ func BenchmarkHistogramWrite8(b *testing.B) {
 	benchmarkHistogramWrite(8, b)
 }
 
+func TestHistogramNonMonotonicBuckets(t *testing.T) {
+	testCases := map[string][]float64{
+		"not strictly monotonic":  {1, 2, 2, 3},
+		"not monotonic at all":    {1, 2, 4, 3, 5},
+		"have +Inf in the middle": {1, 2, math.Inf(+1), 3},
+	}
+	for name, buckets := range testCases {
+		func() {
+			defer func() {
+				if r := recover(); r == nil {
+					t.Errorf("Buckets %v are %s but NewHistogram did not panic.", buckets, name)
+				}
+			}()
+			_ = NewHistogram(HistogramOpts{
+				Name:    "test_histogram",
+				Help:    "helpless",
+				Buckets: buckets,
+			})
+		}()
+	}
+}
+
 // Intentionally adding +Inf here to test if that case is handled correctly.
 // Also, getCumulativeCounts depends on it.
 var testBuckets = []float64{-2, -1, -0.5, 0, 0.5, 1, 2, math.Inf(+1)}
@@ -264,7 +286,7 @@ func TestHistogramVecConcurrency(t *testing.T) {
 		for i := 0; i < vecLength; i++ {
 			m := &dto.Metric{}
 			s := his.WithLabelValues(string('A' + i))
-			s.Write(m)
+			s.(Histogram).Write(m)
 
 			if got, want := len(m.Histogram.Bucket), len(testBuckets)-1; got != want {
 				t.Errorf("got %d buckets in protobuf, want %d", got, want)

vendor/github.com/prometheus/client_golang/prometheus/http.go

@@ -62,7 +62,8 @@ func giveBuf(buf *bytes.Buffer) {
 //
 // Deprecated: Please note the issues described in the doc comment of
 // InstrumentHandler. You might want to consider using promhttp.Handler instead
-// (which is non instrumented).
+// (which is not instrumented, but can be instrumented with the tooling provided
+// in package promhttp).
 func Handler() http.Handler {
 	return InstrumentHandler("prometheus", UninstrumentedHandler())
 }
@@ -95,7 +96,7 @@ func UninstrumentedHandler() http.Handler {
 			closer.Close()
 		}
 		if lastErr != nil && buf.Len() == 0 {
-			http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError)
+			http.Error(w, "No metrics encoded, last error:\n\n"+lastErr.Error(), http.StatusInternalServerError)
 			return
 		}
 		header := w.Header()
@@ -158,7 +159,8 @@ func nowSeries(t ...time.Time) nower {
 // value. http_requests_total is a metric vector partitioned by HTTP method
 // (label name "method") and HTTP status code (label name "code").
 //
-// Deprecated: InstrumentHandler has several issues:
+// Deprecated: InstrumentHandler has several issues. Use the tooling provided in
+// package promhttp instead. The issues are the following:
 //
 // - It uses Summaries rather than Histograms. Summaries are not useful if
 // aggregation across multiple instances is required.
@@ -172,9 +174,8 @@ func nowSeries(t ...time.Time) nower {
 // httputil.ReverseProxy is a prominent example for a handler
 // performing such writes.
 //
-// Upcoming versions of this package will provide ways of instrumenting HTTP
-// handlers that are more flexible and have fewer issues. Please prefer direct
-// instrumentation in the meantime.
+// - It has additional issues with HTTP/2, cf.
+// https://github.com/prometheus/client_golang/issues/272.
 func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
 	return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
 }
@@ -184,12 +185,13 @@ func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFun
 // issues).
 //
 // Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as
-// InstrumentHandler is.
+// InstrumentHandler is. Use the tooling provided in package promhttp instead.
 func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
 	return InstrumentHandlerFuncWithOpts(
 		SummaryOpts{
 			Subsystem:   "http",
 			ConstLabels: Labels{"handler": handlerName},
+			Objectives:  map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 		},
 		handlerFunc,
 	)
@@ -222,7 +224,7 @@ func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWri
 // SummaryOpts.
 //
 // Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as
-// InstrumentHandler is.
+// InstrumentHandler is. Use the tooling provided in package promhttp instead.
 func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
 	return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
 }
@@ -233,7 +235,7 @@ func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.Hand
 // SummaryOpts are used.
 //
 // Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons
-// as InstrumentHandler is.
+// as InstrumentHandler is. Use the tooling provided in package promhttp instead.
 func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
 	reqCnt := NewCounterVec(
 		CounterOpts{
@@ -245,34 +247,52 @@ func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.Respo
 		},
 		instLabels,
 	)
+	if err := Register(reqCnt); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			reqCnt = are.ExistingCollector.(*CounterVec)
+		} else {
+			panic(err)
+		}
+	}
 
 	opts.Name = "request_duration_microseconds"
 	opts.Help = "The HTTP request latencies in microseconds."
 	reqDur := NewSummary(opts)
+	if err := Register(reqDur); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			reqDur = are.ExistingCollector.(Summary)
+		} else {
+			panic(err)
+		}
+	}
 
 	opts.Name = "request_size_bytes"
 	opts.Help = "The HTTP request sizes in bytes."
 	reqSz := NewSummary(opts)
+	if err := Register(reqSz); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			reqSz = are.ExistingCollector.(Summary)
+		} else {
+			panic(err)
+		}
+	}
 
 	opts.Name = "response_size_bytes"
 	opts.Help = "The HTTP response sizes in bytes."
 	resSz := NewSummary(opts)
-
-	regReqCnt := MustRegisterOrGet(reqCnt).(*CounterVec)
-	regReqDur := MustRegisterOrGet(reqDur).(Summary)
-	regReqSz := MustRegisterOrGet(reqSz).(Summary)
-	regResSz := MustRegisterOrGet(resSz).(Summary)
+	if err := Register(resSz); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			resSz = are.ExistingCollector.(Summary)
+		} else {
+			panic(err)
+		}
+	}
 
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		now := time.Now()
 
 		delegate := &responseWriterDelegator{ResponseWriter: w}
-		out := make(chan int)
-		urlLen := 0
-		if r.URL != nil {
-			urlLen = len(r.URL.String())
-		}
-		go computeApproximateRequestSize(r, out, urlLen)
+		out := computeApproximateRequestSize(r)
 
 		_, cn := w.(http.CloseNotifier)
 		_, fl := w.(http.Flusher)
@@ -290,30 +310,44 @@ func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.Respo
 
 		method := sanitizeMethod(r.Method)
 		code := sanitizeCode(delegate.status)
-		regReqCnt.WithLabelValues(method, code).Inc()
-		regReqDur.Observe(elapsed)
-		regResSz.Observe(float64(delegate.written))
-		regReqSz.Observe(float64(<-out))
+		reqCnt.WithLabelValues(method, code).Inc()
+		reqDur.Observe(elapsed)
+		resSz.Observe(float64(delegate.written))
+		reqSz.Observe(float64(<-out))
 	})
 }
 
-func computeApproximateRequestSize(r *http.Request, out chan int, s int) {
-	s += len(r.Method)
-	s += len(r.Proto)
-	for name, values := range r.Header {
-		s += len(name)
-		for _, value := range values {
-			s += len(value)
+func computeApproximateRequestSize(r *http.Request) <-chan int {
+	// Get URL length in current go routine for avoiding a race condition.
+	// HandlerFunc that runs in parallel may modify the URL.
+	s := 0
+	if r.URL != nil {
+		s += len(r.URL.String())
+	}
+
+	out := make(chan int, 1)
+
+	go func() {
+		s += len(r.Method)
+		s += len(r.Proto)
+		for name, values := range r.Header {
+			s += len(name)
+			for _, value := range values {
+				s += len(value)
+			}
 		}
-	}
-	s += len(r.Host)
+		s += len(r.Host)
 
-	// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
+		// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
 
-	if r.ContentLength != -1 {
-		s += int(r.ContentLength)
-	}
-	out <- s
+		if r.ContentLength != -1 {
+			s += int(r.ContentLength)
+		}
+		out <- s
+		close(out)
+	}()
+
+	return out
 }
 
 type responseWriterDelegator struct {

vendor/github.com/prometheus/client_golang/prometheus/http_test.go

@@ -44,9 +44,10 @@ func TestInstrumentHandler(t *testing.T) {
 	opts := SummaryOpts{
 		Subsystem:   "http",
 		ConstLabels: Labels{"handler": "test-handler"},
+		Objectives:  map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 	}
 
-	reqCnt := MustRegisterOrGet(NewCounterVec(
+	reqCnt := NewCounterVec(
 		CounterOpts{
 			Namespace:   opts.Namespace,
 			Subsystem:   opts.Subsystem,
@@ -55,19 +56,51 @@ func TestInstrumentHandler(t *testing.T) {
 			ConstLabels: opts.ConstLabels,
 		},
 		instLabels,
-	)).(*CounterVec)
+	)
+	err := Register(reqCnt)
+	if err == nil {
+		t.Fatal("expected reqCnt to be registered already")
+	}
+	if are, ok := err.(AlreadyRegisteredError); ok {
+		reqCnt = are.ExistingCollector.(*CounterVec)
+	} else {
+		t.Fatal("unexpected registration error:", err)
+	}
 
 	opts.Name = "request_duration_microseconds"
 	opts.Help = "The HTTP request latencies in microseconds."
-	reqDur := MustRegisterOrGet(NewSummary(opts)).(Summary)
+	reqDur := NewSummary(opts)
+	err = Register(reqDur)
+	if err == nil {
+		t.Fatal("expected reqDur to be registered already")
+	}
+	if are, ok := err.(AlreadyRegisteredError); ok {
+		reqDur = are.ExistingCollector.(Summary)
+	} else {
+		t.Fatal("unexpected registration error:", err)
+	}
 
 	opts.Name = "request_size_bytes"
 	opts.Help = "The HTTP request sizes in bytes."
-	MustRegisterOrGet(NewSummary(opts))
+	reqSz := NewSummary(opts)
+	err = Register(reqSz)
+	if err == nil {
+		t.Fatal("expected reqSz to be registered already")
+	}
+	if _, ok := err.(AlreadyRegisteredError); !ok {
+		t.Fatal("unexpected registration error:", err)
+	}
 
 	opts.Name = "response_size_bytes"
 	opts.Help = "The HTTP response sizes in bytes."
-	MustRegisterOrGet(NewSummary(opts))
+	resSz := NewSummary(opts)
+	err = Register(resSz)
+	if err == nil {
+		t.Fatal("expected resSz to be registered already")
+	}
+	if _, ok := err.(AlreadyRegisteredError); !ok {
+		t.Fatal("unexpected registration error:", err)
+	}
 
 	reqCnt.Reset()
 
@@ -95,7 +128,7 @@ func TestInstrumentHandler(t *testing.T) {
 	}
 
 	out.Reset()
-	if want, got := 1, len(reqCnt.children); want != got {
+	if want, got := 1, len(reqCnt.metricMap.metrics); want != got {
 		t.Errorf("want %d children in reqCnt, got %d", want, got)
 	}
 	cnt, err := reqCnt.GetMetricWithLabelValues("get", "418")

vendor/github.com/prometheus/client_golang/prometheus/labels.go

@@ -0,0 +1,57 @@
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/prometheus/common/model"
+)
+
+// Labels represents a collection of label name -> value mappings. This type is
+// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
+// metric vector Collectors, e.g.:
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
+//
+// The other use-case is the specification of constant label pairs in Opts or to
+// create a Desc.
+type Labels map[string]string
+
+// reservedLabelPrefix is a prefix which is not legal in user-supplied
+// label names.
+const reservedLabelPrefix = "__"
+
+var errInconsistentCardinality = errors.New("inconsistent label cardinality")
+
+func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
+	if len(labels) != expectedNumberOfValues {
+		return errInconsistentCardinality
+	}
+
+	for name, val := range labels {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label %s: value %q is not valid UTF-8", name, val)
+		}
+	}
+
+	return nil
+}
+
+func validateLabelValues(vals []string, expectedNumberOfValues int) error {
+	if len(vals) != expectedNumberOfValues {
+		return errInconsistentCardinality
+	}
+
+	for _, val := range vals {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label value %q is not valid UTF-8", val)
+		}
+	}
+
+	return nil
+}
+
+func checkLabelName(l string) bool {
+	return model.LabelName(l).IsValid() && !strings.HasPrefix(l, reservedLabelPrefix)
+}

vendor/github.com/prometheus/client_golang/prometheus/metric.go

@@ -79,20 +79,12 @@ type Opts struct {
 	// with the same fully-qualified name must have the same label names in
 	// their ConstLabels.
 	//
-	// Note that in most cases, labels have a value that varies during the
-	// lifetime of a process. Those labels are usually managed with a metric
-	// vector collector (like CounterVec, GaugeVec, UntypedVec). ConstLabels
-	// serve only special purposes. One is for the special case where the
-	// value of a label does not change during the lifetime of a process,
-	// e.g. if the revision of the running binary is put into a
-	// label. Another, more advanced purpose is if more than one Collector
-	// needs to collect Metrics with the same fully-qualified name. In that
-	// case, those Metrics must differ in the values of their
-	// ConstLabels. See the Collector examples.
-	//
-	// If the value of a label never changes (not even between binaries),
-	// that label most likely should not be a label at all (but part of the
-	// metric name).
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
 	ConstLabels Labels
 }
 

vendor/github.com/prometheus/client_golang/prometheus/observer.go

@@ -0,0 +1,52 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Observer is the interface that wraps the Observe method, which is used by
+// Histogram and Summary to add observations.
+type Observer interface {
+	Observe(float64)
+}
+
+// The ObserverFunc type is an adapter to allow the use of ordinary
+// functions as Observers. If f is a function with the appropriate
+// signature, ObserverFunc(f) is an Observer that calls f.
+//
+// This adapter is usually used in connection with the Timer type, and there are
+// two general use cases:
+//
+// The most common one is to use a Gauge as the Observer for a Timer.
+// See the "Gauge" Timer example.
+//
+// The more advanced use case is to create a function that dynamically decides
+// which Observer to use for observing the duration. See the "Complex" Timer
+// example.
+type ObserverFunc func(float64)
+
+// Observe calls f(value). It implements Observer.
+func (f ObserverFunc) Observe(value float64) {
+	f(value)
+}
+
+// ObserverVec is an interface implemented by `HistogramVec` and `SummaryVec`.
+type ObserverVec interface {
+	GetMetricWith(Labels) (Observer, error)
+	GetMetricWithLabelValues(lvs ...string) (Observer, error)
+	With(Labels) Observer
+	WithLabelValues(...string) Observer
+	CurryWith(Labels) (ObserverVec, error)
+	MustCurryWith(Labels) ObserverVec
+
+	Collector
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector.go

@@ -19,10 +19,10 @@ type processCollector struct {
 	pid             int
 	collectFn       func(chan<- Metric)
 	pidFn           func() (int, error)
-	cpuTotal        Counter
-	openFDs, maxFDs Gauge
-	vsize, rss      Gauge
-	startTime       Gauge
+	cpuTotal        *Desc
+	openFDs, maxFDs *Desc
+	vsize, rss      *Desc
+	startTime       *Desc
 }
 
 // NewProcessCollector returns a collector which exports the current state of
@@ -44,40 +44,45 @@ func NewProcessCollectorPIDFn(
 	pidFn func() (int, error),
 	namespace string,
 ) Collector {
+	ns := ""
+	if len(namespace) > 0 {
+		ns = namespace + "_"
+	}
+
 	c := processCollector{
 		pidFn:     pidFn,
 		collectFn: func(chan<- Metric) {},
 
-		cpuTotal: NewCounter(CounterOpts{
-			Namespace: namespace,
-			Name:      "process_cpu_seconds_total",
-			Help:      "Total user and system CPU time spent in seconds.",
-		}),
-		openFDs: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_open_fds",
-			Help:      "Number of open file descriptors.",
-		}),
-		maxFDs: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_max_fds",
-			Help:      "Maximum number of open file descriptors.",
-		}),
-		vsize: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_virtual_memory_bytes",
-			Help:      "Virtual memory size in bytes.",
-		}),
-		rss: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_resident_memory_bytes",
-			Help:      "Resident memory size in bytes.",
-		}),
-		startTime: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_start_time_seconds",
-			Help:      "Start time of the process since unix epoch in seconds.",
-		}),
+		cpuTotal: NewDesc(
+			ns+"process_cpu_seconds_total",
+			"Total user and system CPU time spent in seconds.",
+			nil, nil,
+		),
+		openFDs: NewDesc(
+			ns+"process_open_fds",
+			"Number of open file descriptors.",
+			nil, nil,
+		),
+		maxFDs: NewDesc(
+			ns+"process_max_fds",
+			"Maximum number of open file descriptors.",
+			nil, nil,
+		),
+		vsize: NewDesc(
+			ns+"process_virtual_memory_bytes",
+			"Virtual memory size in bytes.",
+			nil, nil,
+		),
+		rss: NewDesc(
+			ns+"process_resident_memory_bytes",
+			"Resident memory size in bytes.",
+			nil, nil,
+		),
+		startTime: NewDesc(
+			ns+"process_start_time_seconds",
+			"Start time of the process since unix epoch in seconds.",
+			nil, nil,
+		),
 	}
 
 	// Set up process metric collection if supported by the runtime.
@@ -90,12 +95,12 @@ func NewProcessCollectorPIDFn(
 
 // Describe returns all descriptions of the collector.
 func (c *processCollector) Describe(ch chan<- *Desc) {
-	ch <- c.cpuTotal.Desc()
-	ch <- c.openFDs.Desc()
-	ch <- c.maxFDs.Desc()
-	ch <- c.vsize.Desc()
-	ch <- c.rss.Desc()
-	ch <- c.startTime.Desc()
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.vsize
+	ch <- c.rss
+	ch <- c.startTime
 }
 
 // Collect returns the current state of all metrics of the collector.
@@ -117,26 +122,19 @@ func (c *processCollector) processCollect(ch chan<- Metric) {
 	}
 
 	if stat, err := p.NewStat(); err == nil {
-		c.cpuTotal.Set(stat.CPUTime())
-		ch <- c.cpuTotal
-		c.vsize.Set(float64(stat.VirtualMemory()))
-		ch <- c.vsize
-		c.rss.Set(float64(stat.ResidentMemory()))
-		ch <- c.rss
-
+		ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
+		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
+		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
 		if startTime, err := stat.StartTime(); err == nil {
-			c.startTime.Set(startTime)
-			ch <- c.startTime
+			ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
 		}
 	}
 
 	if fds, err := p.FileDescriptorsLen(); err == nil {
-		c.openFDs.Set(float64(fds))
-		ch <- c.openFDs
+		ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
 	}
 
 	if limits, err := p.NewLimits(); err == nil {
-		c.maxFDs.Set(float64(limits.OpenFiles))
-		ch <- c.maxFDs
+		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
 	}
 }

vendor/github.com/prometheus/client_golang/prometheus/process_collector_test.go

@@ -38,18 +38,18 @@ func TestProcessCollector(t *testing.T) {
 	}
 
 	for _, re := range []*regexp.Regexp{
-		regexp.MustCompile("process_cpu_seconds_total [0-9]"),
-		regexp.MustCompile("process_max_fds [1-9]"),
-		regexp.MustCompile("process_open_fds [1-9]"),
-		regexp.MustCompile("process_virtual_memory_bytes [1-9]"),
-		regexp.MustCompile("process_resident_memory_bytes [1-9]"),
-		regexp.MustCompile("process_start_time_seconds [0-9.]{10,}"),
-		regexp.MustCompile("foobar_process_cpu_seconds_total [0-9]"),
-		regexp.MustCompile("foobar_process_max_fds [1-9]"),
-		regexp.MustCompile("foobar_process_open_fds [1-9]"),
-		regexp.MustCompile("foobar_process_virtual_memory_bytes [1-9]"),
-		regexp.MustCompile("foobar_process_resident_memory_bytes [1-9]"),
-		regexp.MustCompile("foobar_process_start_time_seconds [0-9.]{10,}"),
+		regexp.MustCompile("\nprocess_cpu_seconds_total [0-9]"),
+		regexp.MustCompile("\nprocess_max_fds [1-9]"),
+		regexp.MustCompile("\nprocess_open_fds [1-9]"),
+		regexp.MustCompile("\nprocess_virtual_memory_bytes [1-9]"),
+		regexp.MustCompile("\nprocess_resident_memory_bytes [1-9]"),
+		regexp.MustCompile("\nprocess_start_time_seconds [0-9.]{10,}"),
+		regexp.MustCompile("\nfoobar_process_cpu_seconds_total [0-9]"),
+		regexp.MustCompile("\nfoobar_process_max_fds [1-9]"),
+		regexp.MustCompile("\nfoobar_process_open_fds [1-9]"),
+		regexp.MustCompile("\nfoobar_process_virtual_memory_bytes [1-9]"),
+		regexp.MustCompile("\nfoobar_process_resident_memory_bytes [1-9]"),
+		regexp.MustCompile("\nfoobar_process_start_time_seconds [0-9.]{10,}"),
 	} {
 		if !re.Match(buf.Bytes()) {
 			t.Errorf("want body to match %s\n%s", re, buf.String())

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go

@@ -0,0 +1,199 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+)
+
+const (
+	closeNotifier = 1 << iota
+	flusher
+	hijacker
+	readerFrom
+	pusher
+)
+
+type delegator interface {
+	http.ResponseWriter
+
+	Status() int
+	Written() int64
+}
+
+type responseWriterDelegator struct {
+	http.ResponseWriter
+
+	handler, method    string
+	status             int
+	written            int64
+	wroteHeader        bool
+	observeWriteHeader func(int)
+}
+
+func (r *responseWriterDelegator) Status() int {
+	return r.status
+}
+
+func (r *responseWriterDelegator) Written() int64 {
+	return r.written
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+	r.status = code
+	r.wroteHeader = true
+	r.ResponseWriter.WriteHeader(code)
+	if r.observeWriteHeader != nil {
+		r.observeWriteHeader(code)
+	}
+}
+
+func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+	if !r.wroteHeader {
+		r.WriteHeader(http.StatusOK)
+	}
+	n, err := r.ResponseWriter.Write(b)
+	r.written += int64(n)
+	return n, err
+}
+
+type closeNotifierDelegator struct{ *responseWriterDelegator }
+type flusherDelegator struct{ *responseWriterDelegator }
+type hijackerDelegator struct{ *responseWriterDelegator }
+type readerFromDelegator struct{ *responseWriterDelegator }
+
+func (d *closeNotifierDelegator) CloseNotify() <-chan bool {
+	return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+func (d *flusherDelegator) Flush() {
+	d.ResponseWriter.(http.Flusher).Flush()
+}
+func (d *hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return d.ResponseWriter.(http.Hijacker).Hijack()
+}
+func (d *readerFromDelegator) ReadFrom(re io.Reader) (int64, error) {
+	if !d.wroteHeader {
+		d.WriteHeader(http.StatusOK)
+	}
+	n, err := d.ResponseWriter.(io.ReaderFrom).ReadFrom(re)
+	d.written += n
+	return n, err
+}
+
+var pickDelegator = make([]func(*responseWriterDelegator) delegator, 32)
+
+func init() {
+	// TODO(beorn7): Code generation would help here.
+	pickDelegator[0] = func(d *responseWriterDelegator) delegator { // 0
+		return d
+	}
+	pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1
+		return closeNotifierDelegator{d}
+	}
+	pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2
+		return flusherDelegator{d}
+	}
+	pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3
+		return struct {
+			*responseWriterDelegator
+			http.Flusher
+			http.CloseNotifier
+		}{d, &flusherDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4
+		return hijackerDelegator{d}
+	}
+	pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.CloseNotifier
+		}{d, &hijackerDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 6
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+		}{d, &hijackerDelegator{d}, &flusherDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 7
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, &hijackerDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom] = func(d *responseWriterDelegator) delegator { // 8
+		return readerFromDelegator{d}
+	}
+	pickDelegator[readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 9
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, &readerFromDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 10
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+		}{d, &readerFromDelegator{d}, &flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 11
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, &readerFromDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 12
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+		}{d, &readerFromDelegator{d}, &hijackerDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 13
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, &readerFromDelegator{d}, &hijackerDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 14
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, &readerFromDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 15
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, &readerFromDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_1_8.go

@@ -0,0 +1,181 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.8
+
+package promhttp
+
+import (
+	"io"
+	"net/http"
+)
+
+type pusherDelegator struct{ *responseWriterDelegator }
+
+func (d *pusherDelegator) Push(target string, opts *http.PushOptions) error {
+	return d.ResponseWriter.(http.Pusher).Push(target, opts)
+}
+
+func init() {
+	pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16
+		return pusherDelegator{d}
+	}
+	pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.CloseNotifier
+		}{d, &pusherDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+flusher] = func(d *responseWriterDelegator) delegator { // 18
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+		}{d, &pusherDelegator{d}, &flusherDelegator{d}}
+	}
+	pickDelegator[pusher+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 19
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+			http.CloseNotifier
+		}{d, &pusherDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker] = func(d *responseWriterDelegator) delegator { // 20
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+		}{d, &pusherDelegator{d}, &hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 21
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.CloseNotifier
+		}{d, &pusherDelegator{d}, &hijackerDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 22
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+		}{d, &pusherDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { //23
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, &pusherDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom] = func(d *responseWriterDelegator) delegator { // 24
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+		}{d, &pusherDelegator{d}, &readerFromDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 25
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 26
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+		}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 27
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 28
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+		}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 29
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &hijackerDelegator{d}, &closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 30
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 31
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
+	}
+}
+
+func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
+	d := &responseWriterDelegator{
+		ResponseWriter:     w,
+		observeWriteHeader: observeWriteHeaderFunc,
+	}
+
+	id := 0
+	if _, ok := w.(http.CloseNotifier); ok {
+		id += closeNotifier
+	}
+	if _, ok := w.(http.Flusher); ok {
+		id += flusher
+	}
+	if _, ok := w.(http.Hijacker); ok {
+		id += hijacker
+	}
+	if _, ok := w.(io.ReaderFrom); ok {
+		id += readerFrom
+	}
+	if _, ok := w.(http.Pusher); ok {
+		id += pusher
+	}
+
+	return pickDelegator[id](d)
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_pre_1_8.go

@@ -0,0 +1,44 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !go1.8
+
+package promhttp
+
+import (
+	"io"
+	"net/http"
+)
+
+func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
+	d := &responseWriterDelegator{
+		ResponseWriter:     w,
+		observeWriteHeader: observeWriteHeaderFunc,
+	}
+
+	id := 0
+	if _, ok := w.(http.CloseNotifier); ok {
+		id += closeNotifier
+	}
+	if _, ok := w.(http.Flusher); ok {
+		id += flusher
+	}
+	if _, ok := w.(http.Hijacker); ok {
+		id += hijacker
+	}
+	if _, ok := w.(io.ReaderFrom); ok {
+		id += readerFrom
+	}
+
+	return pickDelegator[id](d)
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go

@@ -11,21 +11,24 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Copyright (c) 2013, The Prometheus Authors
-// All rights reserved.
+// Package promhttp provides tooling around HTTP servers and clients.
 //
-// Use of this source code is governed by a BSD-style license that can be found
-// in the LICENSE file.
-
-// Package promhttp contains functions to create http.Handler instances to
-// expose Prometheus metrics via HTTP. In later versions of this package, it
-// will also contain tooling to instrument instances of http.Handler and
-// http.RoundTripper.
+// First, the package allows the creation of http.Handler instances to expose
+// Prometheus metrics via HTTP. promhttp.Handler acts on the
+// prometheus.DefaultGatherer. With HandlerFor, you can create a handler for a
+// custom registry or anything that implements the Gatherer interface. It also
+// allows the creation of handlers that act differently on errors or allow to
+// log errors.
 //
-// promhttp.Handler acts on the prometheus.DefaultGatherer. With HandlerFor,
-// you can create a handler for a custom registry or anything that implements
-// the Gatherer interface. It also allows to create handlers that act
-// differently on errors or allow to log errors.
+// Second, the package provides tooling to instrument instances of http.Handler
+// via middleware. Middleware wrappers follow the naming scheme
+// InstrumentHandlerX, where X describes the intended use of the middleware.
+// See each function's doc comment for specific details.
+//
+// Finally, the package allows for an http.RoundTripper to be instrumented via
+// middleware. Middleware wrappers follow the naming scheme
+// InstrumentRoundTripperX, where X describes the intended use of the
+// middleware. See each function's doc comment for specific details.
 package promhttp
 
 import (
@@ -125,7 +128,7 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
 			closer.Close()
 		}
 		if lastErr != nil && buf.Len() == 0 {
-			http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError)
+			http.Error(w, "No metrics encoded, last error:\n\n"+lastErr.Error(), http.StatusInternalServerError)
 			return
 		}
 		header := w.Header()

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http_test.go

@@ -11,12 +11,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Copyright (c) 2013, The Prometheus Authors
-// All rights reserved.
-//
-// Use of this source code is governed by a BSD-style license that can be found
-// in the LICENSE file.
-
 package promhttp
 
 import (

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go

@@ -0,0 +1,97 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// The RoundTripperFunc type is an adapter to allow the use of ordinary
+// functions as RoundTrippers. If f is a function with the appropriate
+// signature, RountTripperFunc(f) is a RoundTripper that calls f.
+type RoundTripperFunc func(req *http.Request) (*http.Response, error)
+
+// RoundTrip implements the RoundTripper interface.
+func (rt RoundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
+	return rt(r)
+}
+
+// InstrumentRoundTripperInFlight is a middleware that wraps the provided
+// http.RoundTripper. It sets the provided prometheus.Gauge to the number of
+// requests currently handled by the wrapped http.RoundTripper.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripper) RoundTripperFunc {
+	return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+		gauge.Inc()
+		defer gauge.Dec()
+		return next.RoundTrip(r)
+	})
+}
+
+// InstrumentRoundTripperCounter is a middleware that wraps the provided
+// http.RoundTripper to observe the request result with the provided CounterVec.
+// The CounterVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. Partitioning of the CounterVec happens by HTTP status code
+// and/or HTTP method if the respective instance label names are present in the
+// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
+//
+// If the wrapped RoundTripper panics or returns a non-nil error, the Counter
+// is not incremented.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperCounter(counter *prometheus.CounterVec, next http.RoundTripper) RoundTripperFunc {
+	code, method := checkLabels(counter)
+
+	return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+		resp, err := next.RoundTrip(r)
+		if err == nil {
+			counter.With(labels(code, method, r.Method, resp.StatusCode)).Inc()
+		}
+		return resp, err
+	})
+}
+
+// InstrumentRoundTripperDuration is a middleware that wraps the provided
+// http.RoundTripper to observe the request duration with the provided
+// ObserverVec.  The ObserverVec must have zero, one, or two non-const
+// non-curried labels. For those, the only allowed label names are "code" and
+// "method". The function panics otherwise. The Observe method of the Observer
+// in the ObserverVec is called with the request duration in
+// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped RoundTripper panics or returns a non-nil error, no values are
+// reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func InstrumentRoundTripperDuration(obs prometheus.ObserverVec, next http.RoundTripper) RoundTripperFunc {
+	code, method := checkLabels(obs)
+
+	return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+		start := time.Now()
+		resp, err := next.RoundTrip(r)
+		if err == nil {
+			obs.With(labels(code, method, r.Method, resp.StatusCode)).Observe(time.Since(start).Seconds())
+		}
+		return resp, err
+	})
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client_1_8.go

@@ -0,0 +1,144 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.8
+
+package promhttp
+
+import (
+	"context"
+	"crypto/tls"
+	"net/http"
+	"net/http/httptrace"
+	"time"
+)
+
+// InstrumentTrace is used to offer flexibility in instrumenting the available
+// httptrace.ClientTrace hook functions. Each function is passed a float64
+// representing the time in seconds since the start of the http request. A user
+// may choose to use separately buckets Histograms, or implement custom
+// instance labels on a per function basis.
+type InstrumentTrace struct {
+	GotConn              func(float64)
+	PutIdleConn          func(float64)
+	GotFirstResponseByte func(float64)
+	Got100Continue       func(float64)
+	DNSStart             func(float64)
+	DNSDone              func(float64)
+	ConnectStart         func(float64)
+	ConnectDone          func(float64)
+	TLSHandshakeStart    func(float64)
+	TLSHandshakeDone     func(float64)
+	WroteHeaders         func(float64)
+	Wait100Continue      func(float64)
+	WroteRequest         func(float64)
+}
+
+// InstrumentRoundTripperTrace is a middleware that wraps the provided
+// RoundTripper and reports times to hook functions provided in the
+// InstrumentTrace struct. Hook functions that are not present in the provided
+// InstrumentTrace struct are ignored. Times reported to the hook functions are
+// time since the start of the request. Only with Go1.9+, those times are
+// guaranteed to never be negative. (Earlier Go versions are not using a
+// monotonic clock.) Note that partitioning of Histograms is expensive and
+// should be used judiciously.
+//
+// For hook functions that receive an error as an argument, no observations are
+// made in the event of a non-nil error value.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperTrace(it *InstrumentTrace, next http.RoundTripper) RoundTripperFunc {
+	return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+		start := time.Now()
+
+		trace := &httptrace.ClientTrace{
+			GotConn: func(_ httptrace.GotConnInfo) {
+				if it.GotConn != nil {
+					it.GotConn(time.Since(start).Seconds())
+				}
+			},
+			PutIdleConn: func(err error) {
+				if err != nil {
+					return
+				}
+				if it.PutIdleConn != nil {
+					it.PutIdleConn(time.Since(start).Seconds())
+				}
+			},
+			DNSStart: func(_ httptrace.DNSStartInfo) {
+				if it.DNSStart != nil {
+					it.DNSStart(time.Since(start).Seconds())
+				}
+			},
+			DNSDone: func(_ httptrace.DNSDoneInfo) {
+				if it.DNSStart != nil {
+					it.DNSStart(time.Since(start).Seconds())
+				}
+			},
+			ConnectStart: func(_, _ string) {
+				if it.ConnectStart != nil {
+					it.ConnectStart(time.Since(start).Seconds())
+				}
+			},
+			ConnectDone: func(_, _ string, err error) {
+				if err != nil {
+					return
+				}
+				if it.ConnectDone != nil {
+					it.ConnectDone(time.Since(start).Seconds())
+				}
+			},
+			GotFirstResponseByte: func() {
+				if it.GotFirstResponseByte != nil {
+					it.GotFirstResponseByte(time.Since(start).Seconds())
+				}
+			},
+			Got100Continue: func() {
+				if it.Got100Continue != nil {
+					it.Got100Continue(time.Since(start).Seconds())
+				}
+			},
+			TLSHandshakeStart: func() {
+				if it.TLSHandshakeStart != nil {
+					it.TLSHandshakeStart(time.Since(start).Seconds())
+				}
+			},
+			TLSHandshakeDone: func(_ tls.ConnectionState, err error) {
+				if err != nil {
+					return
+				}
+				if it.TLSHandshakeDone != nil {
+					it.TLSHandshakeDone(time.Since(start).Seconds())
+				}
+			},
+			WroteHeaders: func() {
+				if it.WroteHeaders != nil {
+					it.WroteHeaders(time.Since(start).Seconds())
+				}
+			},
+			Wait100Continue: func() {
+				if it.Wait100Continue != nil {
+					it.Wait100Continue(time.Since(start).Seconds())
+				}
+			},
+			WroteRequest: func(_ httptrace.WroteRequestInfo) {
+				if it.WroteRequest != nil {
+					it.WroteRequest(time.Since(start).Seconds())
+				}
+			},
+		}
+		r = r.WithContext(httptrace.WithClientTrace(context.Background(), trace))
+
+		return next.RoundTrip(r)
+	})
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client_1_8_test.go

@@ -0,0 +1,195 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.8
+
+package promhttp
+
+import (
+	"log"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+func TestClientMiddlewareAPI(t *testing.T) {
+	client := http.DefaultClient
+	client.Timeout = 1 * time.Second
+
+	reg := prometheus.NewRegistry()
+
+	inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "client_in_flight_requests",
+		Help: "A gauge of in-flight requests for the wrapped client.",
+	})
+
+	counter := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "client_api_requests_total",
+			Help: "A counter for requests from the wrapped client.",
+		},
+		[]string{"code", "method"},
+	)
+
+	dnsLatencyVec := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "dns_duration_seconds",
+			Help:    "Trace dns latency histogram.",
+			Buckets: []float64{.005, .01, .025, .05},
+		},
+		[]string{"event"},
+	)
+
+	tlsLatencyVec := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "tls_duration_seconds",
+			Help:    "Trace tls latency histogram.",
+			Buckets: []float64{.05, .1, .25, .5},
+		},
+		[]string{"event"},
+	)
+
+	histVec := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "request_duration_seconds",
+			Help:    "A histogram of request latencies.",
+			Buckets: prometheus.DefBuckets,
+		},
+		[]string{"method"},
+	)
+
+	reg.MustRegister(counter, tlsLatencyVec, dnsLatencyVec, histVec, inFlightGauge)
+
+	trace := &InstrumentTrace{
+		DNSStart: func(t float64) {
+			dnsLatencyVec.WithLabelValues("dns_start")
+		},
+		DNSDone: func(t float64) {
+			dnsLatencyVec.WithLabelValues("dns_done")
+		},
+		TLSHandshakeStart: func(t float64) {
+			tlsLatencyVec.WithLabelValues("tls_handshake_start")
+		},
+		TLSHandshakeDone: func(t float64) {
+			tlsLatencyVec.WithLabelValues("tls_handshake_done")
+		},
+	}
+
+	client.Transport = InstrumentRoundTripperInFlight(inFlightGauge,
+		InstrumentRoundTripperCounter(counter,
+			InstrumentRoundTripperTrace(trace,
+				InstrumentRoundTripperDuration(histVec, http.DefaultTransport),
+			),
+		),
+	)
+
+	resp, err := client.Get("http://google.com")
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer resp.Body.Close()
+}
+
+func ExampleInstrumentRoundTripperDuration() {
+	client := http.DefaultClient
+	client.Timeout = 1 * time.Second
+
+	inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "client_in_flight_requests",
+		Help: "A gauge of in-flight requests for the wrapped client.",
+	})
+
+	counter := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "client_api_requests_total",
+			Help: "A counter for requests from the wrapped client.",
+		},
+		[]string{"code", "method"},
+	)
+
+	// dnsLatencyVec uses custom buckets based on expected dns durations.
+	// It has an instance label "event", which is set in the
+	// DNSStart and DNSDonehook functions defined in the
+	// InstrumentTrace struct below.
+	dnsLatencyVec := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "dns_duration_seconds",
+			Help:    "Trace dns latency histogram.",
+			Buckets: []float64{.005, .01, .025, .05},
+		},
+		[]string{"event"},
+	)
+
+	// tlsLatencyVec uses custom buckets based on expected tls durations.
+	// It has an instance label "event", which is set in the
+	// TLSHandshakeStart and TLSHandshakeDone hook functions defined in the
+	// InstrumentTrace struct below.
+	tlsLatencyVec := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "tls_duration_seconds",
+			Help:    "Trace tls latency histogram.",
+			Buckets: []float64{.05, .1, .25, .5},
+		},
+		[]string{"event"},
+	)
+
+	// histVec has no labels, making it a zero-dimensional ObserverVec.
+	histVec := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "request_duration_seconds",
+			Help:    "A histogram of request latencies.",
+			Buckets: prometheus.DefBuckets,
+		},
+		[]string{},
+	)
+
+	// Register all of the metrics in the standard registry.
+	prometheus.MustRegister(counter, tlsLatencyVec, dnsLatencyVec, histVec, inFlightGauge)
+
+	// Define functions for the available httptrace.ClientTrace hook
+	// functions that we want to instrument.
+	trace := &InstrumentTrace{
+		DNSStart: func(t float64) {
+			dnsLatencyVec.WithLabelValues("dns_start")
+		},
+		DNSDone: func(t float64) {
+			dnsLatencyVec.WithLabelValues("dns_done")
+		},
+		TLSHandshakeStart: func(t float64) {
+			tlsLatencyVec.WithLabelValues("tls_handshake_start")
+		},
+		TLSHandshakeDone: func(t float64) {
+			tlsLatencyVec.WithLabelValues("tls_handshake_done")
+		},
+	}
+
+	// Wrap the default RoundTripper with middleware.
+	roundTripper := InstrumentRoundTripperInFlight(inFlightGauge,
+		InstrumentRoundTripperCounter(counter,
+			InstrumentRoundTripperTrace(trace,
+				InstrumentRoundTripperDuration(histVec, http.DefaultTransport),
+			),
+		),
+	)
+
+	// Set the RoundTripper on our client.
+	client.Transport = roundTripper
+
+	resp, err := client.Get("http://google.com")
+	if err != nil {
+		log.Printf("error: %v", err)
+	}
+	defer resp.Body.Close()
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go

@@ -0,0 +1,447 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// magicString is used for the hacky label test in checkLabels. Remove once fixed.
+const magicString = "zZgWfBxLqvG8kc8IMv3POi2Bb0tZI3vAnBx+gBaFi9FyPzB/CzKUer1yufDa"
+
+// InstrumentHandlerInFlight is a middleware that wraps the provided
+// http.Handler. It sets the provided prometheus.Gauge to the number of
+// requests currently handled by the wrapped http.Handler.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		g.Inc()
+		defer g.Dec()
+		next.ServeHTTP(w, r)
+	})
+}
+
+// InstrumentHandlerDuration is a middleware that wraps the provided
+// http.Handler to observe the request duration with the provided ObserverVec.
+// The ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the request duration in seconds. Partitioning happens by HTTP
+// status code and/or HTTP method if the respective instance label names are
+// present in the ObserverVec. For unpartitioned observations, use an
+// ObserverVec with zero labels. Note that partitioning of Histograms is
+// expensive and should be used judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+	code, method := checkLabels(obs)
+
+	if code {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			now := time.Now()
+			d := newDelegator(w, nil)
+			next.ServeHTTP(d, r)
+
+			obs.With(labels(code, method, r.Method, d.Status())).Observe(time.Since(now).Seconds())
+		})
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		now := time.Now()
+		next.ServeHTTP(w, r)
+		obs.With(labels(code, method, r.Method, 0)).Observe(time.Since(now).Seconds())
+	})
+}
+
+// InstrumentHandlerCounter is a middleware that wraps the provided http.Handler
+// to observe the request result with the provided CounterVec.  The CounterVec
+// must have zero, one, or two non-const non-curried labels. For those, the only
+// allowed label names are "code" and "method". The function panics
+// otherwise. Partitioning of the CounterVec happens by HTTP status code and/or
+// HTTP method if the respective instance label names are present in the
+// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, the Counter is not incremented.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler) http.HandlerFunc {
+	code, method := checkLabels(counter)
+
+	if code {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			d := newDelegator(w, nil)
+			next.ServeHTTP(d, r)
+			counter.With(labels(code, method, r.Method, d.Status())).Inc()
+		})
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		next.ServeHTTP(w, r)
+		counter.With(labels(code, method, r.Method, 0)).Inc()
+	})
+}
+
+// InstrumentHandlerTimeToWriteHeader is a middleware that wraps the provided
+// http.Handler to observe with the provided ObserverVec the request duration
+// until the response headers are written. The ObserverVec must have zero, one,
+// or two non-const non-curried labels. For those, the only allowed label names
+// are "code" and "method". The function panics otherwise. The Observe method of
+// the Observer in the ObserverVec is called with the request duration in
+// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped Handler panics before calling WriteHeader, no value is
+// reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+	code, method := checkLabels(obs)
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		now := time.Now()
+		d := newDelegator(w, func(status int) {
+			obs.With(labels(code, method, r.Method, status)).Observe(time.Since(now).Seconds())
+		})
+		next.ServeHTTP(d, r)
+	})
+}
+
+// InstrumentHandlerRequestSize is a middleware that wraps the provided
+// http.Handler to observe the request size with the provided ObserverVec.  The
+// ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the request size in bytes. Partitioning happens by HTTP status
+// code and/or HTTP method if the respective instance label names are present in
+// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
+// labels. Note that partitioning of Histograms is expensive and should be used
+// judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+	code, method := checkLabels(obs)
+
+	if code {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			d := newDelegator(w, nil)
+			next.ServeHTTP(d, r)
+			size := computeApproximateRequestSize(r)
+			obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(size))
+		})
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		next.ServeHTTP(w, r)
+		size := computeApproximateRequestSize(r)
+		obs.With(labels(code, method, r.Method, 0)).Observe(float64(size))
+	})
+}
+
+// InstrumentHandlerResponseSize is a middleware that wraps the provided
+// http.Handler to observe the response size with the provided ObserverVec.  The
+// ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the response size in bytes. Partitioning happens by HTTP status
+// code and/or HTTP method if the respective instance label names are present in
+// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
+// labels. Note that partitioning of Histograms is expensive and should be used
+// judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerResponseSize(obs prometheus.ObserverVec, next http.Handler) http.Handler {
+	code, method := checkLabels(obs)
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		d := newDelegator(w, nil)
+		next.ServeHTTP(d, r)
+		obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(d.Written()))
+	})
+}
+
+func checkLabels(c prometheus.Collector) (code bool, method bool) {
+	// TODO(beorn7): Remove this hacky way to check for instance labels
+	// once Descriptors can have their dimensionality queried.
+	var (
+		desc *prometheus.Desc
+		m    prometheus.Metric
+		pm   dto.Metric
+		lvs  []string
+	)
+
+	// Get the Desc from the Collector.
+	descc := make(chan *prometheus.Desc, 1)
+	c.Describe(descc)
+
+	select {
+	case desc = <-descc:
+	default:
+		panic("no description provided by collector")
+	}
+	select {
+	case <-descc:
+		panic("more than one description provided by collector")
+	default:
+	}
+
+	close(descc)
+
+	// Create a ConstMetric with the Desc. Since we don't know how many
+	// variable labels there are, try for as long as it needs.
+	for err := errors.New("dummy"); err != nil; lvs = append(lvs, magicString) {
+		m, err = prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, lvs...)
+	}
+
+	// Write out the metric into a proto message and look at the labels.
+	// If the value is not the magicString, it is a constLabel, which doesn't interest us.
+	// If the label is curried, it doesn't interest us.
+	// In all other cases, only "code" or "method" is allowed.
+	if err := m.Write(&pm); err != nil {
+		panic("error checking metric for labels")
+	}
+	for _, label := range pm.Label {
+		name, value := label.GetName(), label.GetValue()
+		if value != magicString || isLabelCurried(c, name) {
+			continue
+		}
+		switch name {
+		case "code":
+			code = true
+		case "method":
+			method = true
+		default:
+			panic("metric partitioned with non-supported labels")
+		}
+	}
+	return
+}
+
+func isLabelCurried(c prometheus.Collector, label string) bool {
+	// This is even hackier than the label test above.
+	// We essentially try to curry again and see if it works.
+	// But for that, we need to type-convert to the two
+	// types we use here, ObserverVec or *CounterVec.
+	switch v := c.(type) {
+	case *prometheus.CounterVec:
+		if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+			return false
+		}
+	case prometheus.ObserverVec:
+		if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+			return false
+		}
+	default:
+		panic("unsupported metric vec type")
+	}
+	return true
+}
+
+// emptyLabels is a one-time allocation for non-partitioned metrics to avoid
+// unnecessary allocations on each request.
+var emptyLabels = prometheus.Labels{}
+
+func labels(code, method bool, reqMethod string, status int) prometheus.Labels {
+	if !(code || method) {
+		return emptyLabels
+	}
+	labels := prometheus.Labels{}
+
+	if code {
+		labels["code"] = sanitizeCode(status)
+	}
+	if method {
+		labels["method"] = sanitizeMethod(reqMethod)
+	}
+
+	return labels
+}
+
+func computeApproximateRequestSize(r *http.Request) int {
+	s := 0
+	if r.URL != nil {
+		s += len(r.URL.String())
+	}
+
+	s += len(r.Method)
+	s += len(r.Proto)
+	for name, values := range r.Header {
+		s += len(name)
+		for _, value := range values {
+			s += len(value)
+		}
+	}
+	s += len(r.Host)
+
+	// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
+
+	if r.ContentLength != -1 {
+		s += int(r.ContentLength)
+	}
+	return s
+}
+
+func sanitizeMethod(m string) string {
+	switch m {
+	case "GET", "get":
+		return "get"
+	case "PUT", "put":
+		return "put"
+	case "HEAD", "head":
+		return "head"
+	case "POST", "post":
+		return "post"
+	case "DELETE", "delete":
+		return "delete"
+	case "CONNECT", "connect":
+		return "connect"
+	case "OPTIONS", "options":
+		return "options"
+	case "NOTIFY", "notify":
+		return "notify"
+	default:
+		return strings.ToLower(m)
+	}
+}
+
+// If the wrapped http.Handler has not set a status code, i.e. the value is
+// currently 0, santizeCode will return 200, for consistency with behavior in
+// the stdlib.
+func sanitizeCode(s int) string {
+	switch s {
+	case 100:
+		return "100"
+	case 101:
+		return "101"
+
+	case 200, 0:
+		return "200"
+	case 201:
+		return "201"
+	case 202:
+		return "202"
+	case 203:
+		return "203"
+	case 204:
+		return "204"
+	case 205:
+		return "205"
+	case 206:
+		return "206"
+
+	case 300:
+		return "300"
+	case 301:
+		return "301"
+	case 302:
+		return "302"
+	case 304:
+		return "304"
+	case 305:
+		return "305"
+	case 307:
+		return "307"
+
+	case 400:
+		return "400"
+	case 401:
+		return "401"
+	case 402:
+		return "402"
+	case 403:
+		return "403"
+	case 404:
+		return "404"
+	case 405:
+		return "405"
+	case 406:
+		return "406"
+	case 407:
+		return "407"
+	case 408:
+		return "408"
+	case 409:
+		return "409"
+	case 410:
+		return "410"
+	case 411:
+		return "411"
+	case 412:
+		return "412"
+	case 413:
+		return "413"
+	case 414:
+		return "414"
+	case 415:
+		return "415"
+	case 416:
+		return "416"
+	case 417:
+		return "417"
+	case 418:
+		return "418"
+
+	case 500:
+		return "500"
+	case 501:
+		return "501"
+	case 502:
+		return "502"
+	case 503:
+		return "503"
+	case 504:
+		return "504"
+	case 505:
+		return "505"
+
+	case 428:
+		return "428"
+	case 429:
+		return "429"
+	case 431:
+		return "431"
+	case 511:
+		return "511"
+
+	default:
+		return strconv.Itoa(s)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server_test.go

@@ -0,0 +1,375 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"io"
+	"log"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+func TestLabelCheck(t *testing.T) {
+	scenarios := map[string]struct {
+		varLabels     []string
+		constLabels   []string
+		curriedLabels []string
+		ok            bool
+	}{
+		"empty": {
+			varLabels:     []string{},
+			constLabels:   []string{},
+			curriedLabels: []string{},
+			ok:            true,
+		},
+		"code as single var label": {
+			varLabels:     []string{"code"},
+			constLabels:   []string{},
+			curriedLabels: []string{},
+			ok:            true,
+		},
+		"method as single var label": {
+			varLabels:     []string{"method"},
+			constLabels:   []string{},
+			curriedLabels: []string{},
+			ok:            true,
+		},
+		"cade and method as var labels": {
+			varLabels:     []string{"method", "code"},
+			constLabels:   []string{},
+			curriedLabels: []string{},
+			ok:            true,
+		},
+		"valid case with all labels used": {
+			varLabels:     []string{"code", "method"},
+			constLabels:   []string{"foo", "bar"},
+			curriedLabels: []string{"dings", "bums"},
+			ok:            true,
+		},
+		"unsupported var label": {
+			varLabels:     []string{"foo"},
+			constLabels:   []string{},
+			curriedLabels: []string{},
+			ok:            false,
+		},
+		"mixed var labels": {
+			varLabels:     []string{"method", "foo", "code"},
+			constLabels:   []string{},
+			curriedLabels: []string{},
+			ok:            false,
+		},
+		"unsupported var label but curried": {
+			varLabels:     []string{},
+			constLabels:   []string{},
+			curriedLabels: []string{"foo"},
+			ok:            true,
+		},
+		"mixed var labels but unsupported curried": {
+			varLabels:     []string{"code", "method"},
+			constLabels:   []string{},
+			curriedLabels: []string{"foo"},
+			ok:            true,
+		},
+		"supported label as const and curry": {
+			varLabels:     []string{},
+			constLabels:   []string{"code"},
+			curriedLabels: []string{"method"},
+			ok:            true,
+		},
+		"supported label as const and curry with unsupported as var": {
+			varLabels:     []string{"foo"},
+			constLabels:   []string{"code"},
+			curriedLabels: []string{"method"},
+			ok:            false,
+		},
+	}
+
+	for name, sc := range scenarios {
+		t.Run(name, func(t *testing.T) {
+			constLabels := prometheus.Labels{}
+			for _, l := range sc.constLabels {
+				constLabels[l] = "dummy"
+			}
+			c := prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Name:        "c",
+					Help:        "c help",
+					ConstLabels: constLabels,
+				},
+				append(sc.varLabels, sc.curriedLabels...),
+			)
+			o := prometheus.ObserverVec(prometheus.NewHistogramVec(
+				prometheus.HistogramOpts{
+					Name:        "c",
+					Help:        "c help",
+					ConstLabels: constLabels,
+				},
+				append(sc.varLabels, sc.curriedLabels...),
+			))
+			for _, l := range sc.curriedLabels {
+				c = c.MustCurryWith(prometheus.Labels{l: "dummy"})
+				o = o.MustCurryWith(prometheus.Labels{l: "dummy"})
+			}
+
+			func() {
+				defer func() {
+					if err := recover(); err != nil {
+						if sc.ok {
+							t.Error("unexpected panic:", err)
+						}
+					} else if !sc.ok {
+						t.Error("expected panic")
+					}
+				}()
+				InstrumentHandlerCounter(c, nil)
+			}()
+			func() {
+				defer func() {
+					if err := recover(); err != nil {
+						if sc.ok {
+							t.Error("unexpected panic:", err)
+						}
+					} else if !sc.ok {
+						t.Error("expected panic")
+					}
+				}()
+				InstrumentHandlerDuration(o, nil)
+			}()
+			if sc.ok {
+				// Test if wantCode and wantMethod were detected correctly.
+				var wantCode, wantMethod bool
+				for _, l := range sc.varLabels {
+					if l == "code" {
+						wantCode = true
+					}
+					if l == "method" {
+						wantMethod = true
+					}
+				}
+				gotCode, gotMethod := checkLabels(c)
+				if gotCode != wantCode {
+					t.Errorf("wanted code=%t for counter, got code=%t", wantCode, gotCode)
+				}
+				if gotMethod != wantMethod {
+					t.Errorf("wanted method=%t for counter, got method=%t", wantMethod, gotMethod)
+				}
+				gotCode, gotMethod = checkLabels(o)
+				if gotCode != wantCode {
+					t.Errorf("wanted code=%t for observer, got code=%t", wantCode, gotCode)
+				}
+				if gotMethod != wantMethod {
+					t.Errorf("wanted method=%t for observer, got method=%t", wantMethod, gotMethod)
+				}
+			}
+		})
+	}
+}
+
+func TestMiddlewareAPI(t *testing.T) {
+	reg := prometheus.NewRegistry()
+
+	inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "in_flight_requests",
+		Help: "A gauge of requests currently being served by the wrapped handler.",
+	})
+
+	counter := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "api_requests_total",
+			Help: "A counter for requests to the wrapped handler.",
+		},
+		[]string{"code", "method"},
+	)
+
+	histVec := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:        "response_duration_seconds",
+			Help:        "A histogram of request latencies.",
+			Buckets:     prometheus.DefBuckets,
+			ConstLabels: prometheus.Labels{"handler": "api"},
+		},
+		[]string{"method"},
+	)
+
+	writeHeaderVec := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:        "write_header_duration_seconds",
+			Help:        "A histogram of time to first write latencies.",
+			Buckets:     prometheus.DefBuckets,
+			ConstLabels: prometheus.Labels{"handler": "api"},
+		},
+		[]string{},
+	)
+
+	responseSize := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "push_request_size_bytes",
+			Help:    "A histogram of request sizes for requests.",
+			Buckets: []float64{200, 500, 900, 1500},
+		},
+		[]string{},
+	)
+
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("OK"))
+	})
+
+	reg.MustRegister(inFlightGauge, counter, histVec, responseSize, writeHeaderVec)
+
+	chain := InstrumentHandlerInFlight(inFlightGauge,
+		InstrumentHandlerCounter(counter,
+			InstrumentHandlerDuration(histVec,
+				InstrumentHandlerTimeToWriteHeader(writeHeaderVec,
+					InstrumentHandlerResponseSize(responseSize, handler),
+				),
+			),
+		),
+	)
+
+	r, _ := http.NewRequest("GET", "www.example.com", nil)
+	w := httptest.NewRecorder()
+	chain.ServeHTTP(w, r)
+}
+
+func TestInstrumentTimeToFirstWrite(t *testing.T) {
+	var i int
+	dobs := &responseWriterDelegator{
+		ResponseWriter: httptest.NewRecorder(),
+		observeWriteHeader: func(status int) {
+			i = status
+		},
+	}
+	d := newDelegator(dobs, nil)
+
+	d.WriteHeader(http.StatusOK)
+
+	if i != http.StatusOK {
+		t.Fatalf("failed to execute observeWriteHeader")
+	}
+}
+
+// testResponseWriter is an http.ResponseWriter that also implements
+// http.CloseNotifier, http.Flusher, and io.ReaderFrom.
+type testResponseWriter struct {
+	closeNotifyCalled, flushCalled, readFromCalled bool
+}
+
+func (t *testResponseWriter) Header() http.Header       { return nil }
+func (t *testResponseWriter) Write([]byte) (int, error) { return 0, nil }
+func (t *testResponseWriter) WriteHeader(int)           {}
+func (t *testResponseWriter) CloseNotify() <-chan bool {
+	t.closeNotifyCalled = true
+	return nil
+}
+func (t *testResponseWriter) Flush() { t.flushCalled = true }
+func (t *testResponseWriter) ReadFrom(io.Reader) (int64, error) {
+	t.readFromCalled = true
+	return 0, nil
+}
+
+func TestInterfaceUpgrade(t *testing.T) {
+	w := &testResponseWriter{}
+	d := newDelegator(w, nil)
+	d.(http.CloseNotifier).CloseNotify()
+	if !w.closeNotifyCalled {
+		t.Error("CloseNotify not called")
+	}
+	d.(http.Flusher).Flush()
+	if !w.flushCalled {
+		t.Error("Flush not called")
+	}
+	d.(io.ReaderFrom).ReadFrom(nil)
+	if !w.readFromCalled {
+		t.Error("ReadFrom not called")
+	}
+	if _, ok := d.(http.Hijacker); ok {
+		t.Error("delegator unexpectedly implements http.Hijacker")
+	}
+}
+
+func ExampleInstrumentHandlerDuration() {
+	inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "in_flight_requests",
+		Help: "A gauge of requests currently being served by the wrapped handler.",
+	})
+
+	counter := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "api_requests_total",
+			Help: "A counter for requests to the wrapped handler.",
+		},
+		[]string{"code", "method"},
+	)
+
+	// duration is partitioned by the HTTP method and handler. It uses custom
+	// buckets based on the expected request duration.
+	duration := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "request_duration_seconds",
+			Help:    "A histogram of latencies for requests.",
+			Buckets: []float64{.25, .5, 1, 2.5, 5, 10},
+		},
+		[]string{"handler", "method"},
+	)
+
+	// responseSize has no labels, making it a zero-dimensional
+	// ObserverVec.
+	responseSize := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "response_size_bytes",
+			Help:    "A histogram of response sizes for requests.",
+			Buckets: []float64{200, 500, 900, 1500},
+		},
+		[]string{},
+	)
+
+	// Create the handlers that will be wrapped by the middleware.
+	pushHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("Push"))
+	})
+	pullHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("Pull"))
+	})
+
+	// Register all of the metrics in the standard registry.
+	prometheus.MustRegister(inFlightGauge, counter, duration, responseSize)
+
+	// Instrument the handlers with all the metrics, injecting the "handler"
+	// label by currying.
+	pushChain := InstrumentHandlerInFlight(inFlightGauge,
+		InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "push"}),
+			InstrumentHandlerCounter(counter,
+				InstrumentHandlerResponseSize(responseSize, pushHandler),
+			),
+		),
+	)
+	pullChain := InstrumentHandlerInFlight(inFlightGauge,
+		InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "pull"}),
+			InstrumentHandlerCounter(counter,
+				InstrumentHandlerResponseSize(responseSize, pullHandler),
+			),
+		),
+	)
+
+	http.Handle("/metrics", Handler())
+	http.Handle("/push", pushChain)
+	http.Handle("/pull", pullChain)
+
+	if err := http.ListenAndServe(":3000", nil); err != nil {
+		log.Fatal(err)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/push/example_add_from_gatherer_test.go

@@ -0,0 +1,84 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright (c) 2013, The Prometheus Authors
+// All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file.
+
+package push_test
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/push"
+)
+
+var (
+	completionTime = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "db_backup_last_completion_timestamp_seconds",
+		Help: "The timestamp of the last completion of a DB backup, successful or not.",
+	})
+	successTime = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "db_backup_last_success_timestamp_seconds",
+		Help: "The timestamp of the last successful completion of a DB backup.",
+	})
+	duration = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "db_backup_duration_seconds",
+		Help: "The duration of the last DB backup in seconds.",
+	})
+	records = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "db_backup_records_processed",
+		Help: "The number of records processed in the last DB backup.",
+	})
+)
+
+func performBackup() (int, error) {
+	// Perform the backup and return the number of backed up records and any
+	// applicable error.
+	// ...
+	return 42, nil
+}
+
+func ExampleAddFromGatherer() {
+	registry := prometheus.NewRegistry()
+	registry.MustRegister(completionTime, duration, records)
+	// Note that successTime is not registered at this time.
+
+	start := time.Now()
+	n, err := performBackup()
+	records.Set(float64(n))
+	// Note that time.Since only uses a monotonic clock in Go1.9+.
+	duration.Set(time.Since(start).Seconds())
+	completionTime.SetToCurrentTime()
+	if err != nil {
+		fmt.Println("DB backup failed:", err)
+	} else {
+		// Only now register successTime.
+		registry.MustRegister(successTime)
+		successTime.SetToCurrentTime()
+	}
+	// AddFromGatherer is used here rather than FromGatherer to not delete a
+	// previously pushed success timestamp in case of a failure of this
+	// backup.
+	if err := push.AddFromGatherer(
+		"db_backup", nil,
+		"http://pushgateway:9091",
+		registry,
+	); err != nil {
+		fmt.Println("Could not push to Pushgateway:", err)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/push/examples_test.go

@@ -15,7 +15,6 @@ package push_test
 
 import (
 	"fmt"
-	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/push"
@@ -24,9 +23,9 @@ import (
 func ExampleCollectors() {
 	completionTime := prometheus.NewGauge(prometheus.GaugeOpts{
 		Name: "db_backup_last_completion_timestamp_seconds",
-		Help: "The timestamp of the last succesful completion of a DB backup.",
+		Help: "The timestamp of the last successful completion of a DB backup.",
 	})
-	completionTime.Set(float64(time.Now().Unix()))
+	completionTime.SetToCurrentTime()
 	if err := push.Collectors(
 		"db_backup", push.HostnameGroupingKey(),
 		"http://pushgateway:9091",
@@ -35,22 +34,3 @@ func ExampleCollectors() {
 		fmt.Println("Could not push completion time to Pushgateway:", err)
 	}
 }
-
-func ExampleRegistry() {
-	registry := prometheus.NewRegistry()
-
-	completionTime := prometheus.NewGauge(prometheus.GaugeOpts{
-		Name: "db_backup_last_completion_timestamp_seconds",
-		Help: "The timestamp of the last succesful completion of a DB backup.",
-	})
-	registry.MustRegister(completionTime)
-
-	completionTime.Set(float64(time.Now().Unix()))
-	if err := push.FromGatherer(
-		"db_backup", push.HostnameGroupingKey(),
-		"http://pushgateway:9091",
-		registry,
-	); err != nil {
-		fmt.Println("Could not push completion time to Pushgateway:", err)
-	}
-}

vendor/github.com/prometheus/client_golang/prometheus/push/push.go

@@ -84,7 +84,7 @@ func push(job string, grouping map[string]string, pushURL string, g prometheus.G
 	}
 	urlComponents := []string{url.QueryEscape(job)}
 	for ln, lv := range grouping {
-		if !model.LabelNameRE.MatchString(ln) {
+		if !model.LabelName(ln).IsValid() {
 			return fmt.Errorf("grouping label has invalid name: %s", ln)
 		}
 		if strings.Contains(lv, "/") {

vendor/github.com/prometheus/client_golang/prometheus/registry.go

@@ -20,6 +20,7 @@ import (
 	"os"
 	"sort"
 	"sync"
+	"unicode/utf8"
 
 	"github.com/golang/protobuf/proto"
 
@@ -80,7 +81,7 @@ func NewPedanticRegistry() *Registry {
 
 // Registerer is the interface for the part of a registry in charge of
 // registering and unregistering. Users of custom registries should use
-// Registerer as type for registration purposes (rather then the Registry type
+// Registerer as type for registration purposes (rather than the Registry type
 // directly). In that way, they are free to use custom Registerer implementation
 // (e.g. for testing purposes).
 type Registerer interface {
@@ -152,38 +153,6 @@ func MustRegister(cs ...Collector) {
 	DefaultRegisterer.MustRegister(cs...)
 }
 
-// RegisterOrGet registers the provided Collector with the DefaultRegisterer and
-// returns the Collector, unless an equal Collector was registered before, in
-// which case that Collector is returned.
-//
-// Deprecated: RegisterOrGet is merely a convenience function for the
-// implementation as described in the documentation for
-// AlreadyRegisteredError. As the use case is relatively rare, this function
-// will be removed in a future version of this package to clean up the
-// namespace.
-func RegisterOrGet(c Collector) (Collector, error) {
-	if err := Register(c); err != nil {
-		if are, ok := err.(AlreadyRegisteredError); ok {
-			return are.ExistingCollector, nil
-		}
-		return nil, err
-	}
-	return c, nil
-}
-
-// MustRegisterOrGet behaves like RegisterOrGet but panics instead of returning
-// an error.
-//
-// Deprecated: This is deprecated for the same reason RegisterOrGet is. See
-// there for details.
-func MustRegisterOrGet(c Collector) Collector {
-	c, err := RegisterOrGet(c)
-	if err != nil {
-		panic(err)
-	}
-	return c
-}
-
 // Unregister removes the registration of the provided Collector from the
 // DefaultRegisterer.
 //
@@ -201,25 +170,6 @@ func (gf GathererFunc) Gather() ([]*dto.MetricFamily, error) {
 	return gf()
 }
 
-// SetMetricFamilyInjectionHook replaces the DefaultGatherer with one that
-// gathers from the previous DefaultGatherers but then merges the MetricFamily
-// protobufs returned from the provided hook function with the MetricFamily
-// protobufs returned from the original DefaultGatherer.
-//
-// Deprecated: This function manipulates the DefaultGatherer variable. Consider
-// the implications, i.e. don't do this concurrently with any uses of the
-// DefaultGatherer. In the rare cases where you need to inject MetricFamily
-// protobufs directly, it is recommended to use a custom Registry and combine it
-// with a custom Gatherer using the Gatherers type (see
-// there). SetMetricFamilyInjectionHook only exists for compatibility reasons
-// with previous versions of this package.
-func SetMetricFamilyInjectionHook(hook func() []*dto.MetricFamily) {
-	DefaultGatherer = Gatherers{
-		DefaultGatherer,
-		GathererFunc(func() ([]*dto.MetricFamily, error) { return hook(), nil }),
-	}
-}
-
 // AlreadyRegisteredError is returned by the Register method if the Collector to
 // be registered has already been registered before, or a different Collector
 // that collects the same metrics has been registered before. Registration fails
@@ -294,7 +244,7 @@ func (r *Registry) Register(c Collector) error {
 	}()
 	r.mtx.Lock()
 	defer r.mtx.Unlock()
-	// Coduct various tests...
+	// Conduct various tests...
 	for desc := range descChan {
 
 		// Is the descriptor valid at all?
@@ -447,7 +397,7 @@ func (r *Registry) Gather() ([]*dto.MetricFamily, error) {
 
 	// Drain metricChan in case of premature return.
 	defer func() {
-		for _ = range metricChan {
+		for range metricChan {
 		}
 	}()
 
@@ -683,7 +633,7 @@ func (s metricSorter) Less(i, j int) bool {
 	return s[i].GetTimestampMs() < s[j].GetTimestampMs()
 }
 
-// normalizeMetricFamilies returns a MetricFamily slice whith empty
+// normalizeMetricFamilies returns a MetricFamily slice with empty
 // MetricFamilies pruned and the remaining MetricFamilies sorted by name within
 // the slice, with the contained Metrics sorted within each MetricFamily.
 func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
@@ -706,7 +656,7 @@ func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily)
 
 // checkMetricConsistency checks if the provided Metric is consistent with the
 // provided MetricFamily. It also hashed the Metric labels and the MetricFamily
-// name. If the resulting hash is alread in the provided metricHashes, an error
+// name. If the resulting hash is already in the provided metricHashes, an error
 // is returned. If not, it is added to metricHashes. The provided dimHashes maps
 // MetricFamily names to their dimHash (hashed sorted label names). If dimHashes
 // doesn't yet contain a hash for the provided MetricFamily, it is
@@ -730,6 +680,12 @@ func checkMetricConsistency(
 		)
 	}
 
+	for _, labelPair := range dtoMetric.GetLabel() {
+		if !utf8.ValidString(*labelPair.Value) {
+			return fmt.Errorf("collected metric's label %s is not utf8: %#v", *labelPair.Name, *labelPair.Value)
+		}
+	}
+
 	// Is the metric unique (i.e. no other metric with the same name and the same label values)?
 	h := hashNew()
 	h = hashAdd(h, metricFamily.GetName())

vendor/github.com/prometheus/client_golang/prometheus/registry_test.go

@@ -209,6 +209,34 @@ metric: <
 	expectedMetricFamilyMergedWithExternalAsProtoCompactText := []byte(`name:"name" help:"docstring" type:COUNTER metric:<label:<name:"constname" value:"constvalue" > label:<name:"labelname" value:"different_val" > counter:<value:42 > > metric:<label:<name:"constname" value:"constvalue" > label:<name:"labelname" value:"val1" > counter:<value:1 > > metric:<label:<name:"constname" value:"constvalue" > label:<name:"labelname" value:"val2" > counter:<value:1 > > 
 `)
 
+	externalMetricFamilyWithInvalidLabelValue := &dto.MetricFamily{
+		Name: proto.String("name"),
+		Help: proto.String("docstring"),
+		Type: dto.MetricType_COUNTER.Enum(),
+		Metric: []*dto.Metric{
+			{
+				Label: []*dto.LabelPair{
+					{
+						Name:  proto.String("constname"),
+						Value: proto.String("\xFF"),
+					},
+					{
+						Name:  proto.String("labelname"),
+						Value: proto.String("different_val"),
+					},
+				},
+				Counter: &dto.Counter{
+					Value: proto.Float64(42),
+				},
+			},
+		},
+	}
+
+	expectedMetricFamilyInvalidLabelValueAsText := []byte(`An error has occurred during metrics gathering:
+
+collected metric's label constname is not utf8: "\xff"
+`)
+
 	type output struct {
 		headers map[string]string
 		body    []byte
@@ -452,6 +480,22 @@ metric: <
 				externalMetricFamilyWithSameName,
 			},
 		},
+		{ // 16
+			headers: map[string]string{
+				"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=compact-text",
+			},
+			out: output{
+				headers: map[string]string{
+					"Content-Type": `text/plain; charset=utf-8`,
+				},
+				body: expectedMetricFamilyInvalidLabelValueAsText,
+			},
+			collector: metricVec,
+			externalMF: []*dto.MetricFamily{
+				externalMetricFamily,
+				externalMetricFamilyWithInvalidLabelValue,
+			},
+		},
 	}
 	for i, scenario := range scenarios {
 		registry := prometheus.NewPedanticRegistry()
@@ -526,20 +570,21 @@ func TestRegisterWithOrGet(t *testing.T) {
 		},
 		[]string{"foo", "bar"},
 	)
-	if err := prometheus.Register(original); err != nil {
+	var err error
+	if err = prometheus.Register(original); err != nil {
 		t.Fatal(err)
 	}
-	if err := prometheus.Register(equalButNotSame); err == nil {
+	if err = prometheus.Register(equalButNotSame); err == nil {
 		t.Fatal("expected error when registringe equal collector")
 	}
-	existing, err := prometheus.RegisterOrGet(equalButNotSame)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if existing != original {
-		t.Error("expected original collector but got something else")
-	}
-	if existing == equalButNotSame {
-		t.Error("expected original callector but got new one")
+	if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
+		if are.ExistingCollector != original {
+			t.Error("expected original collector but got something else")
+		}
+		if are.ExistingCollector == equalButNotSame {
+			t.Error("expected original callector but got new one")
+		}
+	} else {
+		t.Error("unexpected error:", err)
 	}
 }

vendor/github.com/prometheus/client_golang/prometheus/summary.go

@@ -36,7 +36,10 @@ const quantileLabel = "quantile"
 //
 // A typical use-case is the observation of request latencies. By default, a
 // Summary provides the median, the 90th and the 99th percentile of the latency
-// as rank estimations.
+// as rank estimations. However, the default behavior will change in the
+// upcoming v0.10 of the library. There will be no rank estiamtions at all by
+// default. For a sane transition, it is recommended to set the desired rank
+// estimations explicitly.
 //
 // Note that the rank estimations cannot be aggregated in a meaningful way with
 // the Prometheus query language (i.e. you cannot average or add them). If you
@@ -54,6 +57,9 @@ type Summary interface {
 }
 
 // DefObjectives are the default Summary quantile values.
+//
+// Deprecated: DefObjectives will not be used as the default objectives in
+// v0.10 of the library. The default Summary will have no quantiles then.
 var (
 	DefObjectives = map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001}
 
@@ -75,8 +81,10 @@ const (
 )
 
 // SummaryOpts bundles the options for creating a Summary metric. It is
-// mandatory to set Name and Help to a non-empty string. All other fields are
-// optional and can safely be left at their zero value.
+// mandatory to set Name and Help to a non-empty string. While all other fields
+// are optional and can safely be left at their zero value, it is recommended to
+// explicitly set the Objectives field to the desired value as the default value
+// will change in the upcoming v0.10 of the library.
 type SummaryOpts struct {
 	// Namespace, Subsystem, and Name are components of the fully-qualified
 	// name of the Summary (created by joining these components with
@@ -93,29 +101,28 @@ type SummaryOpts struct {
 	// string.
 	Help string
 
-	// ConstLabels are used to attach fixed labels to this
-	// Summary. Summaries with the same fully-qualified name must have the
-	// same label names in their ConstLabels.
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
 	//
-	// Note that in most cases, labels have a value that varies during the
-	// lifetime of a process. Those labels are usually managed with a
-	// SummaryVec. ConstLabels serve only special purposes. One is for the
-	// special case where the value of a label does not change during the
-	// lifetime of a process, e.g. if the revision of the running binary is
-	// put into a label. Another, more advanced purpose is if more than one
-	// Collector needs to collect Summaries with the same fully-qualified
-	// name. In that case, those Summaries must differ in the values of
-	// their ConstLabels. See the Collector examples.
-	//
-	// If the value of a label never changes (not even between binaries),
-	// that label most likely should not be a label at all (but part of the
-	// metric name).
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
 	ConstLabels Labels
 
 	// Objectives defines the quantile rank estimates with their respective
-	// absolute error. If Objectives[q] = e, then the value reported
-	// for q will be the φ-quantile value for some φ between q-e and q+e.
-	// The default value is DefObjectives.
+	// absolute error. If Objectives[q] = e, then the value reported for q
+	// will be the φ-quantile value for some φ between q-e and q+e.  The
+	// default value is DefObjectives. It is used if Objectives is left at
+	// its zero value (i.e. nil). To create a Summary without Objectives,
+	// set it to an empty map (i.e. map[float64]float64{}).
+	//
+	// Deprecated: Note that the current value of DefObjectives is
+	// deprecated. It will be replaced by an empty map in v0.10 of the
+	// library. Please explicitly set Objectives to the desired value.
 	Objectives map[float64]float64
 
 	// MaxAge defines the duration for which an observation stays relevant
@@ -183,7 +190,7 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 		}
 	}
 
-	if len(opts.Objectives) == 0 {
+	if opts.Objectives == nil {
 		opts.Objectives = DefObjectives
 	}
 
@@ -390,12 +397,11 @@ func (s quantSort) Less(i, j int) bool {
 // (e.g. HTTP request latencies, partitioned by status code and method). Create
 // instances with NewSummaryVec.
 type SummaryVec struct {
-	*MetricVec
+	*metricVec
 }
 
 // NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
+// partitioned by the given label names.
 func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
@@ -404,47 +410,116 @@ func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
 		opts.ConstLabels,
 	)
 	return &SummaryVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
 			return newSummary(desc, opts, lvs...)
 		}),
 	}
 }
 
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns a Summary and not a
-// Metric so that no type conversion is required.
-func (m *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Summary, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+// GetMetricWithLabelValues returns the Summary for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Summary is created.
+//
+// It is possible to call this method without using the returned Summary to only
+// create the new Summary but leave it at its starting value, a Summary without
+// any observations.
+//
+// Keeping the Summary for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Summary from the SummaryVec. In that case,
+// the Summary will still exist, but it will not be exported anymore, even if a
+// Summary with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
 	if metric != nil {
-		return metric.(Summary), err
+		return metric.(Observer), err
 	}
 	return nil, err
 }
 
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns a Summary and not a Metric so that no
-// type conversion is required.
-func (m *SummaryVec) GetMetricWith(labels Labels) (Summary, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
+// GetMetricWith returns the Summary for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Summary is created. Implications of
+// creating a Summary without using it and keeping the Summary for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *SummaryVec) GetMetricWith(labels Labels) (Observer, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
 	if metric != nil {
-		return metric.(Summary), err
+		return metric.(Observer), err
 	}
 	return nil, err
 }
 
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
 //     myVec.WithLabelValues("404", "GET").Observe(42.21)
-func (m *SummaryVec) WithLabelValues(lvs ...string) Summary {
-	return m.MetricVec.WithLabelValues(lvs...).(Summary)
+func (v *SummaryVec) WithLabelValues(lvs ...string) Observer {
+	s, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return s
 }
 
 // With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21)
-func (m *SummaryVec) With(labels Labels) Summary {
-	return m.MetricVec.With(labels).(Summary)
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
+func (v *SummaryVec) With(labels Labels) Observer {
+	s, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return s
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the SummaryVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *SummaryVec) CurryWith(labels Labels) (ObserverVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &SummaryVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *SummaryVec) MustCurryWith(labels Labels) ObserverVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
 }
 
 type constSummary struct {
@@ -505,8 +580,8 @@ func NewConstSummary(
 	quantiles map[float64]float64,
 	labelValues ...string,
 ) (Metric, error) {
-	if len(desc.variableLabels) != len(labelValues) {
-		return nil, errInconsistentCardinality
+	if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
+		return nil, err
 	}
 	return &constSummary{
 		desc:       desc,

vendor/github.com/prometheus/client_golang/prometheus/summary_test.go

@@ -25,6 +25,45 @@ import (
 	dto "github.com/prometheus/client_model/go"
 )
 
+func TestSummaryWithDefaultObjectives(t *testing.T) {
+	reg := NewRegistry()
+	summaryWithDefaultObjectives := NewSummary(SummaryOpts{
+		Name: "default_objectives",
+		Help: "Test help.",
+	})
+	if err := reg.Register(summaryWithDefaultObjectives); err != nil {
+		t.Error(err)
+	}
+
+	m := &dto.Metric{}
+	if err := summaryWithDefaultObjectives.Write(m); err != nil {
+		t.Error(err)
+	}
+	if len(m.GetSummary().Quantile) != len(DefObjectives) {
+		t.Error("expected default objectives in summary")
+	}
+}
+
+func TestSummaryWithoutObjectives(t *testing.T) {
+	reg := NewRegistry()
+	summaryWithEmptyObjectives := NewSummary(SummaryOpts{
+		Name:       "empty_objectives",
+		Help:       "Test help.",
+		Objectives: map[float64]float64{},
+	})
+	if err := reg.Register(summaryWithEmptyObjectives); err != nil {
+		t.Error(err)
+	}
+
+	m := &dto.Metric{}
+	if err := summaryWithEmptyObjectives.Write(m); err != nil {
+		t.Error(err)
+	}
+	if len(m.GetSummary().Quantile) != 0 {
+		t.Error("expected no objectives in summary")
+	}
+}
+
 func benchmarkSummaryObserve(w int, b *testing.B) {
 	b.StopTimer()
 
@@ -136,8 +175,9 @@ func TestSummaryConcurrency(t *testing.T) {
 		end.Add(concLevel)
 
 		sum := NewSummary(SummaryOpts{
-			Name: "test_summary",
-			Help: "helpless",
+			Name:       "test_summary",
+			Help:       "helpless",
+			Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 		})
 
 		allVars := make([]float64, total)
@@ -223,8 +263,9 @@ func TestSummaryVecConcurrency(t *testing.T) {
 
 		sum := NewSummaryVec(
 			SummaryOpts{
-				Name: "test_summary",
-				Help: "helpless",
+				Name:       "test_summary",
+				Help:       "helpless",
+				Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 			},
 			[]string{"label"},
 		)
@@ -260,7 +301,7 @@ func TestSummaryVecConcurrency(t *testing.T) {
 		for i := 0; i < vecLength; i++ {
 			m := &dto.Metric{}
 			s := sum.WithLabelValues(string('A' + i))
-			s.Write(m)
+			s.(Summary).Write(m)
 			if got, want := int(*m.Summary.SampleCount), len(allVars[i]); got != want {
 				t.Errorf("got sample count %d for label %c, want %d", got, 'A'+i, want)
 			}
@@ -305,7 +346,7 @@ func TestSummaryDecay(t *testing.T) {
 	m := &dto.Metric{}
 	i := 0
 	tick := time.NewTicker(time.Millisecond)
-	for _ = range tick.C {
+	for range tick.C {
 		i++
 		sum.Observe(float64(i))
 		if i%10 == 0 {

vendor/github.com/prometheus/client_golang/prometheus/timer.go

@@ -0,0 +1,51 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import "time"
+
+// Timer is a helper type to time functions. Use NewTimer to create new
+// instances.
+type Timer struct {
+	begin    time.Time
+	observer Observer
+}
+
+// NewTimer creates a new Timer. The provided Observer is used to observe a
+// duration in seconds. Timer is usually used to time a function call in the
+// following way:
+//    func TimeMe() {
+//        timer := NewTimer(myHistogram)
+//        defer timer.ObserveDuration()
+//        // Do actual work.
+//    }
+func NewTimer(o Observer) *Timer {
+	return &Timer{
+		begin:    time.Now(),
+		observer: o,
+	}
+}
+
+// ObserveDuration records the duration passed since the Timer was created with
+// NewTimer. It calls the Observe method of the Observer provided during
+// construction with the duration in seconds as an argument. ObserveDuration is
+// usually called with a defer statement.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func (t *Timer) ObserveDuration() {
+	if t.observer != nil {
+		t.observer.Observe(time.Since(t.begin).Seconds())
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/timer_test.go

@@ -0,0 +1,152 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"testing"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+func TestTimerObserve(t *testing.T) {
+	var (
+		his   = NewHistogram(HistogramOpts{Name: "test_histogram"})
+		sum   = NewSummary(SummaryOpts{Name: "test_summary"})
+		gauge = NewGauge(GaugeOpts{Name: "test_gauge"})
+	)
+
+	func() {
+		hisTimer := NewTimer(his)
+		sumTimer := NewTimer(sum)
+		gaugeTimer := NewTimer(ObserverFunc(gauge.Set))
+		defer hisTimer.ObserveDuration()
+		defer sumTimer.ObserveDuration()
+		defer gaugeTimer.ObserveDuration()
+	}()
+
+	m := &dto.Metric{}
+	his.Write(m)
+	if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for histogram, got %d", want, got)
+	}
+	m.Reset()
+	sum.Write(m)
+	if want, got := uint64(1), m.GetSummary().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for summary, got %d", want, got)
+	}
+	m.Reset()
+	gauge.Write(m)
+	if got := m.GetGauge().GetValue(); got <= 0 {
+		t.Errorf("want value > 0 for gauge, got %f", got)
+	}
+}
+
+func TestTimerEmpty(t *testing.T) {
+	emptyTimer := NewTimer(nil)
+	emptyTimer.ObserveDuration()
+	// Do nothing, just demonstrate it works without panic.
+}
+
+func TestTimerConditionalTiming(t *testing.T) {
+	var (
+		his = NewHistogram(HistogramOpts{
+			Name: "test_histogram",
+		})
+		timeMe = true
+		m      = &dto.Metric{}
+	)
+
+	timedFunc := func() {
+		timer := NewTimer(ObserverFunc(func(v float64) {
+			if timeMe {
+				his.Observe(v)
+			}
+		}))
+		defer timer.ObserveDuration()
+	}
+
+	timedFunc() // This will time.
+	his.Write(m)
+	if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for histogram, got %d", want, got)
+	}
+
+	timeMe = false
+	timedFunc() // This will not time again.
+	m.Reset()
+	his.Write(m)
+	if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for histogram, got %d", want, got)
+	}
+}
+
+func TestTimerByOutcome(t *testing.T) {
+	var (
+		his = NewHistogramVec(
+			HistogramOpts{Name: "test_histogram"},
+			[]string{"outcome"},
+		)
+		outcome = "foo"
+		m       = &dto.Metric{}
+	)
+
+	timedFunc := func() {
+		timer := NewTimer(ObserverFunc(func(v float64) {
+			his.WithLabelValues(outcome).Observe(v)
+		}))
+		defer timer.ObserveDuration()
+
+		if outcome == "foo" {
+			outcome = "bar"
+			return
+		}
+		outcome = "foo"
+	}
+
+	timedFunc()
+	his.WithLabelValues("foo").(Histogram).Write(m)
+	if want, got := uint64(0), m.GetHistogram().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for 'foo' histogram, got %d", want, got)
+	}
+	m.Reset()
+	his.WithLabelValues("bar").(Histogram).Write(m)
+	if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for 'bar' histogram, got %d", want, got)
+	}
+
+	timedFunc()
+	m.Reset()
+	his.WithLabelValues("foo").(Histogram).Write(m)
+	if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for 'foo' histogram, got %d", want, got)
+	}
+	m.Reset()
+	his.WithLabelValues("bar").(Histogram).Write(m)
+	if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for 'bar' histogram, got %d", want, got)
+	}
+
+	timedFunc()
+	m.Reset()
+	his.WithLabelValues("foo").(Histogram).Write(m)
+	if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for 'foo' histogram, got %d", want, got)
+	}
+	m.Reset()
+	his.WithLabelValues("bar").(Histogram).Write(m)
+	if want, got := uint64(2), m.GetHistogram().GetSampleCount(); want != got {
+		t.Errorf("want %d observations for 'bar' histogram, got %d", want, got)
+	}
+
+}

vendor/github.com/prometheus/client_golang/prometheus/untyped.go

@@ -13,108 +13,12 @@
 
 package prometheus
 
-// Untyped is a Metric that represents a single numerical value that can
-// arbitrarily go up and down.
-//
-// An Untyped metric works the same as a Gauge. The only difference is that to
-// no type information is implied.
-//
-// To create Untyped instances, use NewUntyped.
-type Untyped interface {
-	Metric
-	Collector
-
-	// Set sets the Untyped metric to an arbitrary value.
-	Set(float64)
-	// Inc increments the Untyped metric by 1.
-	Inc()
-	// Dec decrements the Untyped metric by 1.
-	Dec()
-	// Add adds the given value to the Untyped metric. (The value can be
-	// negative, resulting in a decrease.)
-	Add(float64)
-	// Sub subtracts the given value from the Untyped metric. (The value can
-	// be negative, resulting in an increase.)
-	Sub(float64)
-}
-
 // UntypedOpts is an alias for Opts. See there for doc comments.
 type UntypedOpts Opts
 
-// NewUntyped creates a new Untyped metric from the provided UntypedOpts.
-func NewUntyped(opts UntypedOpts) Untyped {
-	return newValue(NewDesc(
-		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
-		opts.Help,
-		nil,
-		opts.ConstLabels,
-	), UntypedValue, 0)
-}
-
-// UntypedVec is a Collector that bundles a set of Untyped metrics that all
-// share the same Desc, but have different values for their variable
-// labels. This is used if you want to count the same thing partitioned by
-// various dimensions. Create instances with NewUntypedVec.
-type UntypedVec struct {
-	*MetricVec
-}
-
-// NewUntypedVec creates a new UntypedVec based on the provided UntypedOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
-func NewUntypedVec(opts UntypedOpts, labelNames []string) *UntypedVec {
-	desc := NewDesc(
-		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
-		opts.Help,
-		labelNames,
-		opts.ConstLabels,
-	)
-	return &UntypedVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
-			return newValue(desc, UntypedValue, 0, lvs...)
-		}),
-	}
-}
-
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns an Untyped and not a
-// Metric so that no type conversion is required.
-func (m *UntypedVec) GetMetricWithLabelValues(lvs ...string) (Untyped, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
-	if metric != nil {
-		return metric.(Untyped), err
-	}
-	return nil, err
-}
-
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns an Untyped and not a Metric so that no
-// type conversion is required.
-func (m *UntypedVec) GetMetricWith(labels Labels) (Untyped, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
-	if metric != nil {
-		return metric.(Untyped), err
-	}
-	return nil, err
-}
-
-// WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
-//     myVec.WithLabelValues("404", "GET").Add(42)
-func (m *UntypedVec) WithLabelValues(lvs ...string) Untyped {
-	return m.MetricVec.WithLabelValues(lvs...).(Untyped)
-}
-
-// With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
-func (m *UntypedVec) With(labels Labels) Untyped {
-	return m.MetricVec.With(labels).(Untyped)
-}
-
-// UntypedFunc is an Untyped whose value is determined at collect time by
-// calling a provided function.
+// UntypedFunc works like GaugeFunc but the collected metric is of type
+// "Untyped". UntypedFunc is useful to mirror an external metric of unknown
+// type.
 //
 // To create UntypedFunc instances, use NewUntypedFunc.
 type UntypedFunc interface {

vendor/github.com/prometheus/client_golang/prometheus/value.go

@@ -14,11 +14,8 @@
 package prometheus
 
 import (
-	"errors"
 	"fmt"
-	"math"
 	"sort"
-	"sync/atomic"
 
 	dto "github.com/prometheus/client_model/go"
 
@@ -36,77 +33,6 @@ const (
 	UntypedValue
 )
 
-var errInconsistentCardinality = errors.New("inconsistent label cardinality")
-
-// value is a generic metric for simple values. It implements Metric, Collector,
-// Counter, Gauge, and Untyped. Its effective type is determined by
-// ValueType. This is a low-level building block used by the library to back the
-// implementations of Counter, Gauge, and Untyped.
-type value struct {
-	// valBits containst the bits of the represented float64 value. It has
-	// to go first in the struct to guarantee alignment for atomic
-	// operations.  http://golang.org/pkg/sync/atomic/#pkg-note-BUG
-	valBits uint64
-
-	selfCollector
-
-	desc       *Desc
-	valType    ValueType
-	labelPairs []*dto.LabelPair
-}
-
-// newValue returns a newly allocated value with the given Desc, ValueType,
-// sample value and label values. It panics if the number of label
-// values is different from the number of variable labels in Desc.
-func newValue(desc *Desc, valueType ValueType, val float64, labelValues ...string) *value {
-	if len(labelValues) != len(desc.variableLabels) {
-		panic(errInconsistentCardinality)
-	}
-	result := &value{
-		desc:       desc,
-		valType:    valueType,
-		valBits:    math.Float64bits(val),
-		labelPairs: makeLabelPairs(desc, labelValues),
-	}
-	result.init(result)
-	return result
-}
-
-func (v *value) Desc() *Desc {
-	return v.desc
-}
-
-func (v *value) Set(val float64) {
-	atomic.StoreUint64(&v.valBits, math.Float64bits(val))
-}
-
-func (v *value) Inc() {
-	v.Add(1)
-}
-
-func (v *value) Dec() {
-	v.Add(-1)
-}
-
-func (v *value) Add(val float64) {
-	for {
-		oldBits := atomic.LoadUint64(&v.valBits)
-		newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
-		if atomic.CompareAndSwapUint64(&v.valBits, oldBits, newBits) {
-			return
-		}
-	}
-}
-
-func (v *value) Sub(val float64) {
-	v.Add(val * -1)
-}
-
-func (v *value) Write(out *dto.Metric) error {
-	val := math.Float64frombits(atomic.LoadUint64(&v.valBits))
-	return populateMetric(v.valType, val, v.labelPairs, out)
-}
-
 // valueFunc is a generic metric for simple values retrieved on collect time
 // from a function. It implements Metric and Collector. Its effective type is
 // determined by ValueType. This is a low-level building block used by the
@@ -153,8 +79,8 @@ func (v *valueFunc) Write(out *dto.Metric) error {
 // the Collect method. NewConstMetric returns an error if the length of
 // labelValues is not consistent with the variable labels in Desc.
 func NewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) (Metric, error) {
-	if len(desc.variableLabels) != len(labelValues) {
-		return nil, errInconsistentCardinality
+	if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
+		return nil, err
 	}
 	return &constMetric{
 		desc:       desc,

vendor/github.com/prometheus/client_golang/prometheus/value_test.go

@@ -0,0 +1,43 @@
+package prometheus
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestNewConstMetricInvalidLabelValues(t *testing.T) {
+	testCases := []struct {
+		desc   string
+		labels Labels
+	}{
+		{
+			desc:   "non utf8 label value",
+			labels: Labels{"a": "\xFF"},
+		},
+		{
+			desc:   "not enough label values",
+			labels: Labels{},
+		},
+		{
+			desc:   "too many label values",
+			labels: Labels{"a": "1", "b": "2"},
+		},
+	}
+
+	for _, test := range testCases {
+		metricDesc := NewDesc(
+			"sample_value",
+			"sample value",
+			[]string{"a"},
+			Labels{},
+		)
+
+		expectPanic(t, func() {
+			MustNewConstMetric(metricDesc, CounterValue, 0.3, "\xFF")
+		}, fmt.Sprintf("WithLabelValues: expected panic because: %s", test.desc))
+
+		if _, err := NewConstMetric(metricDesc, CounterValue, 0.3, "\xFF"); err == nil {
+			t.Errorf("NewConstMetric: expected error because: %s", test.desc)
+		}
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/vec.go

@@ -20,33 +20,180 @@ import (
 	"github.com/prometheus/common/model"
 )
 
-// MetricVec is a Collector to bundle metrics of the same name that
-// differ in their label values. MetricVec is usually not used directly but as a
-// building block for implementations of vectors of a given metric
-// type. GaugeVec, CounterVec, SummaryVec, and UntypedVec are examples already
-// provided in this package.
-type MetricVec struct {
-	mtx      sync.RWMutex // Protects the children.
-	children map[uint64][]metricWithLabelValues
-	desc     *Desc
+// metricVec is a Collector to bundle metrics of the same name that differ in
+// their label values. metricVec is not used directly (and therefore
+// unexported). It is used as a building block for implementations of vectors of
+// a given metric type, like GaugeVec, CounterVec, SummaryVec, and HistogramVec.
+// It also handles label currying. It uses basicMetricVec internally.
+type metricVec struct {
+	*metricMap
 
-	newMetric   func(labelValues ...string) Metric
-	hashAdd     func(h uint64, s string) uint64 // replace hash function for testing collision handling
+	curry []curriedLabelValue
+
+	// hashAdd and hashAddByte can be replaced for testing collision handling.
+	hashAdd     func(h uint64, s string) uint64
 	hashAddByte func(h uint64, b byte) uint64
 }
 
-// newMetricVec returns an initialized MetricVec. The concrete value is
-// returned for embedding into another struct.
-func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec {
-	return &MetricVec{
-		children:    map[uint64][]metricWithLabelValues{},
-		desc:        desc,
-		newMetric:   newMetric,
+// newMetricVec returns an initialized metricVec.
+func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *metricVec {
+	return &metricVec{
+		metricMap: &metricMap{
+			metrics:   map[uint64][]metricWithLabelValues{},
+			desc:      desc,
+			newMetric: newMetric,
+		},
 		hashAdd:     hashAdd,
 		hashAddByte: hashAddByte,
 	}
 }
 
+// DeleteLabelValues removes the metric where the variable labels are the same
+// as those passed in as labels (same order as the VariableLabels in Desc). It
+// returns true if a metric was deleted.
+//
+// It is not an error if the number of label values is not the same as the
+// number of VariableLabels in Desc. However, such inconsistent label count can
+// never match an actual metric, so the method will always return false in that
+// case.
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider Delete(Labels) as an
+// alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the CounterVec example.
+func (m *metricVec) DeleteLabelValues(lvs ...string) bool {
+	h, err := m.hashLabelValues(lvs)
+	if err != nil {
+		return false
+	}
+
+	return m.metricMap.deleteByHashWithLabelValues(h, lvs, m.curry)
+}
+
+// Delete deletes the metric where the variable labels are the same as those
+// passed in as labels. It returns true if a metric was deleted.
+//
+// It is not an error if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc. However, such inconsistent Labels
+// can never match an actual metric, so the method will always return false in
+// that case.
+//
+// This method is used for the same purpose as DeleteLabelValues(...string). See
+// there for pros and cons of the two methods.
+func (m *metricVec) Delete(labels Labels) bool {
+	h, err := m.hashLabels(labels)
+	if err != nil {
+		return false
+	}
+
+	return m.metricMap.deleteByHashWithLabels(h, labels, m.curry)
+}
+
+func (m *metricVec) curryWith(labels Labels) (*metricVec, error) {
+	var (
+		newCurry []curriedLabelValue
+		oldCurry = m.curry
+		iCurry   int
+	)
+	for i, label := range m.desc.variableLabels {
+		val, ok := labels[label]
+		if iCurry < len(oldCurry) && oldCurry[iCurry].index == i {
+			if ok {
+				return nil, fmt.Errorf("label name %q is already curried", label)
+			}
+			newCurry = append(newCurry, oldCurry[iCurry])
+			iCurry++
+		} else {
+			if !ok {
+				continue // Label stays uncurried.
+			}
+			newCurry = append(newCurry, curriedLabelValue{i, val})
+		}
+	}
+	if l := len(oldCurry) + len(labels) - len(newCurry); l > 0 {
+		return nil, fmt.Errorf("%d unknown label(s) found during currying", l)
+	}
+
+	return &metricVec{
+		metricMap:   m.metricMap,
+		curry:       newCurry,
+		hashAdd:     m.hashAdd,
+		hashAddByte: m.hashAddByte,
+	}, nil
+}
+
+func (m *metricVec) getMetricWithLabelValues(lvs ...string) (Metric, error) {
+	h, err := m.hashLabelValues(lvs)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.metricMap.getOrCreateMetricWithLabelValues(h, lvs, m.curry), nil
+}
+
+func (m *metricVec) getMetricWith(labels Labels) (Metric, error) {
+	h, err := m.hashLabels(labels)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.metricMap.getOrCreateMetricWithLabels(h, labels, m.curry), nil
+}
+
+func (m *metricVec) hashLabelValues(vals []string) (uint64, error) {
+	if err := validateLabelValues(vals, len(m.desc.variableLabels)-len(m.curry)); err != nil {
+		return 0, err
+	}
+
+	var (
+		h             = hashNew()
+		curry         = m.curry
+		iVals, iCurry int
+	)
+	for i := 0; i < len(m.desc.variableLabels); i++ {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			h = m.hashAdd(h, curry[iCurry].value)
+			iCurry++
+		} else {
+			h = m.hashAdd(h, vals[iVals])
+			iVals++
+		}
+		h = m.hashAddByte(h, model.SeparatorByte)
+	}
+	return h, nil
+}
+
+func (m *metricVec) hashLabels(labels Labels) (uint64, error) {
+	if err := validateValuesInLabels(labels, len(m.desc.variableLabels)-len(m.curry)); err != nil {
+		return 0, err
+	}
+
+	var (
+		h      = hashNew()
+		curry  = m.curry
+		iCurry int
+	)
+	for i, label := range m.desc.variableLabels {
+		val, ok := labels[label]
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			if ok {
+				return 0, fmt.Errorf("label name %q is already curried", label)
+			}
+			h = m.hashAdd(h, curry[iCurry].value)
+			iCurry++
+		} else {
+			if !ok {
+				return 0, fmt.Errorf("label name %q missing in label map", label)
+			}
+			h = m.hashAdd(h, val)
+		}
+		h = m.hashAddByte(h, model.SeparatorByte)
+	}
+	return h, nil
+}
+
 // metricWithLabelValues provides the metric and its label values for
 // disambiguation on hash collision.
 type metricWithLabelValues struct {
@@ -54,166 +201,72 @@ type metricWithLabelValues struct {
 	metric Metric
 }
 
-// Describe implements Collector. The length of the returned slice
-// is always one.
-func (m *MetricVec) Describe(ch chan<- *Desc) {
+// curriedLabelValue sets the curried value for a label at the given index.
+type curriedLabelValue struct {
+	index int
+	value string
+}
+
+// metricMap is a helper for metricVec and shared between differently curried
+// metricVecs.
+type metricMap struct {
+	mtx       sync.RWMutex // Protects metrics.
+	metrics   map[uint64][]metricWithLabelValues
+	desc      *Desc
+	newMetric func(labelValues ...string) Metric
+}
+
+// Describe implements Collector. It will send exactly one Desc to the provided
+// channel.
+func (m *metricMap) Describe(ch chan<- *Desc) {
 	ch <- m.desc
 }
 
 // Collect implements Collector.
-func (m *MetricVec) Collect(ch chan<- Metric) {
+func (m *metricMap) Collect(ch chan<- Metric) {
 	m.mtx.RLock()
 	defer m.mtx.RUnlock()
 
-	for _, metrics := range m.children {
+	for _, metrics := range m.metrics {
 		for _, metric := range metrics {
 			ch <- metric.metric
 		}
 	}
 }
 
-// GetMetricWithLabelValues returns the Metric for the given slice of label
-// values (same order as the VariableLabels in Desc). If that combination of
-// label values is accessed for the first time, a new Metric is created.
-//
-// It is possible to call this method without using the returned Metric to only
-// create the new Metric but leave it at its start value (e.g. a Summary or
-// Histogram without any observations). See also the SummaryVec example.
-//
-// Keeping the Metric for later use is possible (and should be considered if
-// performance is critical), but keep in mind that Reset, DeleteLabelValues and
-// Delete can be used to delete the Metric from the MetricVec. In that case, the
-// Metric will still exist, but it will not be exported anymore, even if a
-// Metric with the same label values is created later. See also the CounterVec
-// example.
-//
-// An error is returned if the number of label values is not the same as the
-// number of VariableLabels in Desc.
-//
-// Note that for more than one label value, this method is prone to mistakes
-// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
-// an alternative to avoid that type of mistake. For higher label numbers, the
-// latter has a much more readable (albeit more verbose) syntax, but it comes
-// with a performance overhead (for creating and processing the Labels map).
-// See also the GaugeVec example.
-func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) {
-	h, err := m.hashLabelValues(lvs)
-	if err != nil {
-		return nil, err
-	}
-
-	return m.getOrCreateMetricWithLabelValues(h, lvs), nil
-}
-
-// GetMetricWith returns the Metric for the given Labels map (the label names
-// must match those of the VariableLabels in Desc). If that label map is
-// accessed for the first time, a new Metric is created. Implications of
-// creating a Metric without using it and keeping the Metric for later use are
-// the same as for GetMetricWithLabelValues.
-//
-// An error is returned if the number and names of the Labels are inconsistent
-// with those of the VariableLabels in Desc.
-//
-// This method is used for the same purpose as
-// GetMetricWithLabelValues(...string). See there for pros and cons of the two
-// methods.
-func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) {
-	h, err := m.hashLabels(labels)
-	if err != nil {
-		return nil, err
-	}
-
-	return m.getOrCreateMetricWithLabels(h, labels), nil
-}
-
-// WithLabelValues works as GetMetricWithLabelValues, but panics if an error
-// occurs. The method allows neat syntax like:
-//     httpReqs.WithLabelValues("404", "POST").Inc()
-func (m *MetricVec) WithLabelValues(lvs ...string) Metric {
-	metric, err := m.GetMetricWithLabelValues(lvs...)
-	if err != nil {
-		panic(err)
-	}
-	return metric
-}
-
-// With works as GetMetricWith, but panics if an error occurs. The method allows
-// neat syntax like:
-//     httpReqs.With(Labels{"status":"404", "method":"POST"}).Inc()
-func (m *MetricVec) With(labels Labels) Metric {
-	metric, err := m.GetMetricWith(labels)
-	if err != nil {
-		panic(err)
-	}
-	return metric
-}
-
-// DeleteLabelValues removes the metric where the variable labels are the same
-// as those passed in as labels (same order as the VariableLabels in Desc). It
-// returns true if a metric was deleted.
-//
-// It is not an error if the number of label values is not the same as the
-// number of VariableLabels in Desc.  However, such inconsistent label count can
-// never match an actual Metric, so the method will always return false in that
-// case.
-//
-// Note that for more than one label value, this method is prone to mistakes
-// caused by an incorrect order of arguments. Consider Delete(Labels) as an
-// alternative to avoid that type of mistake. For higher label numbers, the
-// latter has a much more readable (albeit more verbose) syntax, but it comes
-// with a performance overhead (for creating and processing the Labels map).
-// See also the CounterVec example.
-func (m *MetricVec) DeleteLabelValues(lvs ...string) bool {
+// Reset deletes all metrics in this vector.
+func (m *metricMap) Reset() {
 	m.mtx.Lock()
 	defer m.mtx.Unlock()
 
-	h, err := m.hashLabelValues(lvs)
-	if err != nil {
-		return false
+	for h := range m.metrics {
+		delete(m.metrics, h)
 	}
-	return m.deleteByHashWithLabelValues(h, lvs)
-}
-
-// Delete deletes the metric where the variable labels are the same as those
-// passed in as labels. It returns true if a metric was deleted.
-//
-// It is not an error if the number and names of the Labels are inconsistent
-// with those of the VariableLabels in the Desc of the MetricVec. However, such
-// inconsistent Labels can never match an actual Metric, so the method will
-// always return false in that case.
-//
-// This method is used for the same purpose as DeleteLabelValues(...string). See
-// there for pros and cons of the two methods.
-func (m *MetricVec) Delete(labels Labels) bool {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	h, err := m.hashLabels(labels)
-	if err != nil {
-		return false
-	}
-
-	return m.deleteByHashWithLabels(h, labels)
 }
 
 // deleteByHashWithLabelValues removes the metric from the hash bucket h. If
 // there are multiple matches in the bucket, use lvs to select a metric and
 // remove only that metric.
-func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool {
-	metrics, ok := m.children[h]
+func (m *metricMap) deleteByHashWithLabelValues(
+	h uint64, lvs []string, curry []curriedLabelValue,
+) bool {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	metrics, ok := m.metrics[h]
 	if !ok {
 		return false
 	}
 
-	i := m.findMetricWithLabelValues(metrics, lvs)
+	i := findMetricWithLabelValues(metrics, lvs, curry)
 	if i >= len(metrics) {
 		return false
 	}
 
 	if len(metrics) > 1 {
-		m.children[h] = append(metrics[:i], metrics[i+1:]...)
+		m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
 	} else {
-		delete(m.children, h)
+		delete(m.metrics, h)
 	}
 	return true
 }
@@ -221,69 +274,35 @@ func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool {
 // deleteByHashWithLabels removes the metric from the hash bucket h. If there
 // are multiple matches in the bucket, use lvs to select a metric and remove
 // only that metric.
-func (m *MetricVec) deleteByHashWithLabels(h uint64, labels Labels) bool {
-	metrics, ok := m.children[h]
+func (m *metricMap) deleteByHashWithLabels(
+	h uint64, labels Labels, curry []curriedLabelValue,
+) bool {
+	metrics, ok := m.metrics[h]
 	if !ok {
 		return false
 	}
-	i := m.findMetricWithLabels(metrics, labels)
+	i := findMetricWithLabels(m.desc, metrics, labels, curry)
 	if i >= len(metrics) {
 		return false
 	}
 
 	if len(metrics) > 1 {
-		m.children[h] = append(metrics[:i], metrics[i+1:]...)
+		m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
 	} else {
-		delete(m.children, h)
+		delete(m.metrics, h)
 	}
 	return true
 }
 
-// Reset deletes all metrics in this vector.
-func (m *MetricVec) Reset() {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	for h := range m.children {
-		delete(m.children, h)
-	}
-}
-
-func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) {
-	if len(vals) != len(m.desc.variableLabels) {
-		return 0, errInconsistentCardinality
-	}
-	h := hashNew()
-	for _, val := range vals {
-		h = m.hashAdd(h, val)
-		h = m.hashAddByte(h, model.SeparatorByte)
-	}
-	return h, nil
-}
-
-func (m *MetricVec) hashLabels(labels Labels) (uint64, error) {
-	if len(labels) != len(m.desc.variableLabels) {
-		return 0, errInconsistentCardinality
-	}
-	h := hashNew()
-	for _, label := range m.desc.variableLabels {
-		val, ok := labels[label]
-		if !ok {
-			return 0, fmt.Errorf("label name %q missing in label map", label)
-		}
-		h = m.hashAdd(h, val)
-		h = m.hashAddByte(h, model.SeparatorByte)
-	}
-	return h, nil
-}
-
 // getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
 // or creates it and returns the new one.
 //
 // This function holds the mutex.
-func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) Metric {
+func (m *metricMap) getOrCreateMetricWithLabelValues(
+	hash uint64, lvs []string, curry []curriedLabelValue,
+) Metric {
 	m.mtx.RLock()
-	metric, ok := m.getMetricWithLabelValues(hash, lvs)
+	metric, ok := m.getMetricWithHashAndLabelValues(hash, lvs, curry)
 	m.mtx.RUnlock()
 	if ok {
 		return metric
@@ -291,13 +310,11 @@ func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string)
 
 	m.mtx.Lock()
 	defer m.mtx.Unlock()
-	metric, ok = m.getMetricWithLabelValues(hash, lvs)
+	metric, ok = m.getMetricWithHashAndLabelValues(hash, lvs, curry)
 	if !ok {
-		// Copy to avoid allocation in case wo don't go down this code path.
-		copiedLVs := make([]string, len(lvs))
-		copy(copiedLVs, lvs)
-		metric = m.newMetric(copiedLVs...)
-		m.children[hash] = append(m.children[hash], metricWithLabelValues{values: copiedLVs, metric: metric})
+		inlinedLVs := inlineLabelValues(lvs, curry)
+		metric = m.newMetric(inlinedLVs...)
+		m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: inlinedLVs, metric: metric})
 	}
 	return metric
 }
@@ -306,9 +323,11 @@ func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string)
 // or creates it and returns the new one.
 //
 // This function holds the mutex.
-func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metric {
+func (m *metricMap) getOrCreateMetricWithLabels(
+	hash uint64, labels Labels, curry []curriedLabelValue,
+) Metric {
 	m.mtx.RLock()
-	metric, ok := m.getMetricWithLabels(hash, labels)
+	metric, ok := m.getMetricWithHashAndLabels(hash, labels, curry)
 	m.mtx.RUnlock()
 	if ok {
 		return metric
@@ -316,33 +335,37 @@ func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metr
 
 	m.mtx.Lock()
 	defer m.mtx.Unlock()
-	metric, ok = m.getMetricWithLabels(hash, labels)
+	metric, ok = m.getMetricWithHashAndLabels(hash, labels, curry)
 	if !ok {
-		lvs := m.extractLabelValues(labels)
+		lvs := extractLabelValues(m.desc, labels, curry)
 		metric = m.newMetric(lvs...)
-		m.children[hash] = append(m.children[hash], metricWithLabelValues{values: lvs, metric: metric})
+		m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: lvs, metric: metric})
 	}
 	return metric
 }
 
-// getMetricWithLabelValues gets a metric while handling possible collisions in
-// the hash space. Must be called while holding read mutex.
-func (m *MetricVec) getMetricWithLabelValues(h uint64, lvs []string) (Metric, bool) {
-	metrics, ok := m.children[h]
+// getMetricWithHashAndLabelValues gets a metric while handling possible
+// collisions in the hash space. Must be called while holding the read mutex.
+func (m *metricMap) getMetricWithHashAndLabelValues(
+	h uint64, lvs []string, curry []curriedLabelValue,
+) (Metric, bool) {
+	metrics, ok := m.metrics[h]
 	if ok {
-		if i := m.findMetricWithLabelValues(metrics, lvs); i < len(metrics) {
+		if i := findMetricWithLabelValues(metrics, lvs, curry); i < len(metrics) {
 			return metrics[i].metric, true
 		}
 	}
 	return nil, false
 }
 
-// getMetricWithLabels gets a metric while handling possible collisions in
+// getMetricWithHashAndLabels gets a metric while handling possible collisions in
 // the hash space. Must be called while holding read mutex.
-func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool) {
-	metrics, ok := m.children[h]
+func (m *metricMap) getMetricWithHashAndLabels(
+	h uint64, labels Labels, curry []curriedLabelValue,
+) (Metric, bool) {
+	metrics, ok := m.metrics[h]
 	if ok {
-		if i := m.findMetricWithLabels(metrics, labels); i < len(metrics) {
+		if i := findMetricWithLabels(m.desc, metrics, labels, curry); i < len(metrics) {
 			return metrics[i].metric, true
 		}
 	}
@@ -351,9 +374,11 @@ func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool)
 
 // findMetricWithLabelValues returns the index of the matching metric or
 // len(metrics) if not found.
-func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, lvs []string) int {
+func findMetricWithLabelValues(
+	metrics []metricWithLabelValues, lvs []string, curry []curriedLabelValue,
+) int {
 	for i, metric := range metrics {
-		if m.matchLabelValues(metric.values, lvs) {
+		if matchLabelValues(metric.values, lvs, curry) {
 			return i
 		}
 	}
@@ -362,32 +387,51 @@ func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, l
 
 // findMetricWithLabels returns the index of the matching metric or len(metrics)
 // if not found.
-func (m *MetricVec) findMetricWithLabels(metrics []metricWithLabelValues, labels Labels) int {
+func findMetricWithLabels(
+	desc *Desc, metrics []metricWithLabelValues, labels Labels, curry []curriedLabelValue,
+) int {
 	for i, metric := range metrics {
-		if m.matchLabels(metric.values, labels) {
+		if matchLabels(desc, metric.values, labels, curry) {
 			return i
 		}
 	}
 	return len(metrics)
 }
 
-func (m *MetricVec) matchLabelValues(values []string, lvs []string) bool {
-	if len(values) != len(lvs) {
+func matchLabelValues(values []string, lvs []string, curry []curriedLabelValue) bool {
+	if len(values) != len(lvs)+len(curry) {
 		return false
 	}
+	var iLVs, iCurry int
 	for i, v := range values {
-		if v != lvs[i] {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			if v != curry[iCurry].value {
+				return false
+			}
+			iCurry++
+			continue
+		}
+		if v != lvs[iLVs] {
 			return false
 		}
+		iLVs++
 	}
 	return true
 }
 
-func (m *MetricVec) matchLabels(values []string, labels Labels) bool {
-	if len(labels) != len(values) {
+func matchLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool {
+	if len(values) != len(labels)+len(curry) {
 		return false
 	}
-	for i, k := range m.desc.variableLabels {
+	iCurry := 0
+	for i, k := range desc.variableLabels {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			if values[i] != curry[iCurry].value {
+				return false
+			}
+			iCurry++
+			continue
+		}
 		if values[i] != labels[k] {
 			return false
 		}
@@ -395,10 +439,31 @@ func (m *MetricVec) matchLabels(values []string, labels Labels) bool {
 	return true
 }
 
-func (m *MetricVec) extractLabelValues(labels Labels) []string {
-	labelValues := make([]string, len(labels))
-	for i, k := range m.desc.variableLabels {
+func extractLabelValues(desc *Desc, labels Labels, curry []curriedLabelValue) []string {
+	labelValues := make([]string, len(labels)+len(curry))
+	iCurry := 0
+	for i, k := range desc.variableLabels {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			labelValues[i] = curry[iCurry].value
+			iCurry++
+			continue
+		}
 		labelValues[i] = labels[k]
 	}
 	return labelValues
 }
+
+func inlineLabelValues(lvs []string, curry []curriedLabelValue) []string {
+	labelValues := make([]string, len(lvs)+len(curry))
+	var iCurry, iLVs int
+	for i := range labelValues {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			labelValues[i] = curry[iCurry].value
+			iCurry++
+			continue
+		}
+		labelValues[i] = lvs[iLVs]
+		iLVs++
+	}
+	return labelValues
+}

vendor/github.com/prometheus/client_golang/prometheus/vec_test.go

@@ -21,8 +21,8 @@ import (
 )
 
 func TestDelete(t *testing.T) {
-	vec := NewUntypedVec(
-		UntypedOpts{
+	vec := NewGaugeVec(
+		GaugeOpts{
 			Name: "test",
 			Help: "helpless",
 		},
@@ -32,8 +32,8 @@ func TestDelete(t *testing.T) {
 }
 
 func TestDeleteWithCollisions(t *testing.T) {
-	vec := NewUntypedVec(
-		UntypedOpts{
+	vec := NewGaugeVec(
+		GaugeOpts{
 			Name: "test",
 			Help: "helpless",
 		},
@@ -44,12 +44,12 @@ func TestDeleteWithCollisions(t *testing.T) {
 	testDelete(t, vec)
 }
 
-func testDelete(t *testing.T, vec *UntypedVec) {
+func testDelete(t *testing.T, vec *GaugeVec) {
 	if got, want := vec.Delete(Labels{"l1": "v1", "l2": "v2"}), false; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 
-	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Untyped).Set(42)
+	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
 	if got, want := vec.Delete(Labels{"l1": "v1", "l2": "v2"}), true; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
@@ -57,7 +57,7 @@ func testDelete(t *testing.T, vec *UntypedVec) {
 		t.Errorf("got %v, want %v", got, want)
 	}
 
-	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Untyped).Set(42)
+	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
 	if got, want := vec.Delete(Labels{"l2": "v2", "l1": "v1"}), true; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
@@ -65,7 +65,7 @@ func testDelete(t *testing.T, vec *UntypedVec) {
 		t.Errorf("got %v, want %v", got, want)
 	}
 
-	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Untyped).Set(42)
+	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
 	if got, want := vec.Delete(Labels{"l2": "v1", "l1": "v2"}), false; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
@@ -75,8 +75,8 @@ func testDelete(t *testing.T, vec *UntypedVec) {
 }
 
 func TestDeleteLabelValues(t *testing.T) {
-	vec := NewUntypedVec(
-		UntypedOpts{
+	vec := NewGaugeVec(
+		GaugeOpts{
 			Name: "test",
 			Help: "helpless",
 		},
@@ -86,8 +86,8 @@ func TestDeleteLabelValues(t *testing.T) {
 }
 
 func TestDeleteLabelValuesWithCollisions(t *testing.T) {
-	vec := NewUntypedVec(
-		UntypedOpts{
+	vec := NewGaugeVec(
+		GaugeOpts{
 			Name: "test",
 			Help: "helpless",
 		},
@@ -98,13 +98,13 @@ func TestDeleteLabelValuesWithCollisions(t *testing.T) {
 	testDeleteLabelValues(t, vec)
 }
 
-func testDeleteLabelValues(t *testing.T, vec *UntypedVec) {
+func testDeleteLabelValues(t *testing.T, vec *GaugeVec) {
 	if got, want := vec.DeleteLabelValues("v1", "v2"), false; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 
-	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Untyped).Set(42)
-	vec.With(Labels{"l1": "v1", "l2": "v3"}).(Untyped).Set(42) // Add junk data for collision.
+	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
+	vec.With(Labels{"l1": "v1", "l2": "v3"}).(Gauge).Set(42) // Add junk data for collision.
 	if got, want := vec.DeleteLabelValues("v1", "v2"), true; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
@@ -115,7 +115,7 @@ func testDeleteLabelValues(t *testing.T, vec *UntypedVec) {
 		t.Errorf("got %v, want %v", got, want)
 	}
 
-	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Untyped).Set(42)
+	vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
 	// Delete out of order.
 	if got, want := vec.DeleteLabelValues("v2", "v1"), false; got != want {
 		t.Errorf("got %v, want %v", got, want)
@@ -126,8 +126,8 @@ func testDeleteLabelValues(t *testing.T, vec *UntypedVec) {
 }
 
 func TestMetricVec(t *testing.T) {
-	vec := NewUntypedVec(
-		UntypedOpts{
+	vec := NewGaugeVec(
+		GaugeOpts{
 			Name: "test",
 			Help: "helpless",
 		},
@@ -137,8 +137,8 @@ func TestMetricVec(t *testing.T) {
 }
 
 func TestMetricVecWithCollisions(t *testing.T) {
-	vec := NewUntypedVec(
-		UntypedOpts{
+	vec := NewGaugeVec(
+		GaugeOpts{
 			Name: "test",
 			Help: "helpless",
 		},
@@ -149,7 +149,7 @@ func TestMetricVecWithCollisions(t *testing.T) {
 	testMetricVec(t, vec)
 }
 
-func testMetricVec(t *testing.T, vec *UntypedVec) {
+func testMetricVec(t *testing.T, vec *GaugeVec) {
 	vec.Reset() // Actually test Reset now!
 
 	var pair [2]string
@@ -162,11 +162,11 @@ func testMetricVec(t *testing.T, vec *UntypedVec) {
 		vec.WithLabelValues(pair[0], pair[1]).Inc()
 
 		expected[[2]string{"v1", "v2"}]++
-		vec.WithLabelValues("v1", "v2").(Untyped).Inc()
+		vec.WithLabelValues("v1", "v2").(Gauge).Inc()
 	}
 
 	var total int
-	for _, metrics := range vec.children {
+	for _, metrics := range vec.metricMap.metrics {
 		for _, metric := range metrics {
 			total++
 			copy(pair[:], metric.values)
@@ -175,7 +175,7 @@ func testMetricVec(t *testing.T, vec *UntypedVec) {
 			if err := metric.metric.Write(&metricOut); err != nil {
 				t.Fatal(err)
 			}
-			actual := *metricOut.Untyped.Value
+			actual := *metricOut.Gauge.Value
 
 			var actualPair [2]string
 			for i, label := range metricOut.Label {
@@ -201,7 +201,7 @@ func testMetricVec(t *testing.T, vec *UntypedVec) {
 
 	vec.Reset()
 
-	if len(vec.children) > 0 {
+	if len(vec.metricMap.metrics) > 0 {
 		t.Fatalf("reset failed")
 	}
 }
@@ -239,10 +239,233 @@ func TestCounterVecEndToEndWithCollision(t *testing.T) {
 	}
 }
 
+func TestCurryVec(t *testing.T) {
+	vec := NewCounterVec(
+		CounterOpts{
+			Name: "test",
+			Help: "helpless",
+		},
+		[]string{"one", "two", "three"},
+	)
+	testCurryVec(t, vec)
+}
+
+func TestCurryVecWithCollisions(t *testing.T) {
+	vec := NewCounterVec(
+		CounterOpts{
+			Name: "test",
+			Help: "helpless",
+		},
+		[]string{"one", "two", "three"},
+	)
+	vec.hashAdd = func(h uint64, s string) uint64 { return 1 }
+	vec.hashAddByte = func(h uint64, b byte) uint64 { return 1 }
+	testCurryVec(t, vec)
+}
+
+func testCurryVec(t *testing.T, vec *CounterVec) {
+
+	assertMetrics := func(t *testing.T) {
+		n := 0
+		for _, m := range vec.metricMap.metrics {
+			n += len(m)
+		}
+		if n != 2 {
+			t.Error("expected two metrics, got", n)
+		}
+		m := &dto.Metric{}
+		c1, err := vec.GetMetricWithLabelValues("1", "2", "3")
+		if err != nil {
+			t.Fatal("unexpected error getting metric:", err)
+		}
+		c1.Write(m)
+		if want, got := 1., m.GetCounter().GetValue(); want != got {
+			t.Errorf("want %f as counter value, got %f", want, got)
+		}
+		m.Reset()
+		c2, err := vec.GetMetricWithLabelValues("11", "22", "33")
+		if err != nil {
+			t.Fatal("unexpected error getting metric:", err)
+		}
+		c2.Write(m)
+		if want, got := 1., m.GetCounter().GetValue(); want != got {
+			t.Errorf("want %f as counter value, got %f", want, got)
+		}
+	}
+
+	assertNoMetric := func(t *testing.T) {
+		if n := len(vec.metricMap.metrics); n != 0 {
+			t.Error("expected no metrics, got", n)
+		}
+	}
+
+	t.Run("zero labels", func(t *testing.T) {
+		c1 := vec.MustCurryWith(nil)
+		c2 := vec.MustCurryWith(nil)
+		c1.WithLabelValues("1", "2", "3").Inc()
+		c2.With(Labels{"one": "11", "two": "22", "three": "33"}).Inc()
+		assertMetrics(t)
+		if !c1.Delete(Labels{"one": "1", "two": "2", "three": "3"}) {
+			t.Error("deletion failed")
+		}
+		if !c2.DeleteLabelValues("11", "22", "33") {
+			t.Error("deletion failed")
+		}
+		assertNoMetric(t)
+	})
+	t.Run("first label", func(t *testing.T) {
+		c1 := vec.MustCurryWith(Labels{"one": "1"})
+		c2 := vec.MustCurryWith(Labels{"one": "11"})
+		c1.WithLabelValues("2", "3").Inc()
+		c2.With(Labels{"two": "22", "three": "33"}).Inc()
+		assertMetrics(t)
+		if c1.Delete(Labels{"two": "22", "three": "33"}) {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if c2.DeleteLabelValues("2", "3") {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if !c1.Delete(Labels{"two": "2", "three": "3"}) {
+			t.Error("deletion failed")
+		}
+		if !c2.DeleteLabelValues("22", "33") {
+			t.Error("deletion failed")
+		}
+		assertNoMetric(t)
+	})
+	t.Run("middle label", func(t *testing.T) {
+		c1 := vec.MustCurryWith(Labels{"two": "2"})
+		c2 := vec.MustCurryWith(Labels{"two": "22"})
+		c1.WithLabelValues("1", "3").Inc()
+		c2.With(Labels{"one": "11", "three": "33"}).Inc()
+		assertMetrics(t)
+		if c1.Delete(Labels{"one": "11", "three": "33"}) {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if c2.DeleteLabelValues("1", "3") {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if !c1.Delete(Labels{"one": "1", "three": "3"}) {
+			t.Error("deletion failed")
+		}
+		if !c2.DeleteLabelValues("11", "33") {
+			t.Error("deletion failed")
+		}
+		assertNoMetric(t)
+	})
+	t.Run("last label", func(t *testing.T) {
+		c1 := vec.MustCurryWith(Labels{"three": "3"})
+		c2 := vec.MustCurryWith(Labels{"three": "33"})
+		c1.WithLabelValues("1", "2").Inc()
+		c2.With(Labels{"one": "11", "two": "22"}).Inc()
+		assertMetrics(t)
+		if c1.Delete(Labels{"two": "22", "one": "11"}) {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if c2.DeleteLabelValues("1", "2") {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if !c1.Delete(Labels{"two": "2", "one": "1"}) {
+			t.Error("deletion failed")
+		}
+		if !c2.DeleteLabelValues("11", "22") {
+			t.Error("deletion failed")
+		}
+		assertNoMetric(t)
+	})
+	t.Run("two labels", func(t *testing.T) {
+		c1 := vec.MustCurryWith(Labels{"three": "3", "one": "1"})
+		c2 := vec.MustCurryWith(Labels{"three": "33", "one": "11"})
+		c1.WithLabelValues("2").Inc()
+		c2.With(Labels{"two": "22"}).Inc()
+		assertMetrics(t)
+		if c1.Delete(Labels{"two": "22"}) {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if c2.DeleteLabelValues("2") {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if !c1.Delete(Labels{"two": "2"}) {
+			t.Error("deletion failed")
+		}
+		if !c2.DeleteLabelValues("22") {
+			t.Error("deletion failed")
+		}
+		assertNoMetric(t)
+	})
+	t.Run("all labels", func(t *testing.T) {
+		c1 := vec.MustCurryWith(Labels{"three": "3", "two": "2", "one": "1"})
+		c2 := vec.MustCurryWith(Labels{"three": "33", "one": "11", "two": "22"})
+		c1.WithLabelValues().Inc()
+		c2.With(nil).Inc()
+		assertMetrics(t)
+		if !c1.Delete(Labels{}) {
+			t.Error("deletion failed")
+		}
+		if !c2.DeleteLabelValues() {
+			t.Error("deletion failed")
+		}
+		assertNoMetric(t)
+	})
+	t.Run("double curry", func(t *testing.T) {
+		c1 := vec.MustCurryWith(Labels{"three": "3"}).MustCurryWith(Labels{"one": "1"})
+		c2 := vec.MustCurryWith(Labels{"three": "33"}).MustCurryWith(Labels{"one": "11"})
+		c1.WithLabelValues("2").Inc()
+		c2.With(Labels{"two": "22"}).Inc()
+		assertMetrics(t)
+		if c1.Delete(Labels{"two": "22"}) {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if c2.DeleteLabelValues("2") {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if !c1.Delete(Labels{"two": "2"}) {
+			t.Error("deletion failed")
+		}
+		if !c2.DeleteLabelValues("22") {
+			t.Error("deletion failed")
+		}
+		assertNoMetric(t)
+	})
+	t.Run("use already curried label", func(t *testing.T) {
+		c1 := vec.MustCurryWith(Labels{"three": "3"})
+		if _, err := c1.GetMetricWithLabelValues("1", "2", "3"); err == nil {
+			t.Error("expected error when using already curried label")
+		}
+		if _, err := c1.GetMetricWith(Labels{"one": "1", "two": "2", "three": "3"}); err == nil {
+			t.Error("expected error when using already curried label")
+		}
+		assertNoMetric(t)
+		c1.WithLabelValues("1", "2").Inc()
+		if c1.Delete(Labels{"one": "1", "two": "2", "three": "3"}) {
+			t.Error("deletion unexpectedly succeeded")
+		}
+		if !c1.Delete(Labels{"one": "1", "two": "2"}) {
+			t.Error("deletion failed")
+		}
+		assertNoMetric(t)
+	})
+	t.Run("curry already curried label", func(t *testing.T) {
+		if _, err := vec.MustCurryWith(Labels{"three": "3"}).CurryWith(Labels{"three": "33"}); err == nil {
+			t.Error("currying unexpectedly succeeded")
+		} else if err.Error() != `label name "three" is already curried` {
+			t.Error("currying returned unexpected error:", err)
+		}
+
+	})
+	t.Run("unknown label", func(t *testing.T) {
+		if _, err := vec.CurryWith(Labels{"foo": "bar"}); err == nil {
+			t.Error("currying unexpectedly succeeded")
+		} else if err.Error() != "1 unknown label(s) found during currying" {
+			t.Error("currying returned unexpected error:", err)
+		}
+	})
+}
+
 func BenchmarkMetricVecWithLabelValuesBasic(b *testing.B) {
 	benchmarkMetricVecWithLabelValues(b, map[string][]string{
-		"l1": []string{"onevalue"},
-		"l2": []string{"twovalue"},
+		"l1": {"onevalue"},
+		"l2": {"twovalue"},
 	})
 }
 
@@ -290,8 +513,8 @@ func benchmarkMetricVecWithLabelValues(b *testing.B, labels map[string][]string)
 	}
 
 	values := make([]string, len(labels)) // Value cache for permutations.
-	vec := NewUntypedVec(
-		UntypedOpts{
+	vec := NewGaugeVec(
+		GaugeOpts{
 			Name: "test",
 			Help: "helpless",
 		},