MM-28859 Add feature flag managment system using split.io and remove viper. (#15954)

* Add feature flag managment system using split.io and remove viper.

* Fixing tests.

* Attempt to fix postgres tests.

* Fix watch filepath for advanced logging.

* Review fixes.

* Some error wrapping.

* Remove unessisary store interface.

* Desanitize SplitKey

* Simplify.

* Review feedback.

* Rename split mlog adatper to split logger.

* fsInner

* Style.

* Restore oldcfg test.

* Downgrading non-actionable feature flag errors to warnings.

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

vendor/github.com/splitio/go-toolkit/v3/LICENSE

@@ -0,0 +1,13 @@
+Copyright © 2020 Split Software, Inc.
+
+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.

vendor/github.com/splitio/go-toolkit/v3/asynctask/asynctasks.go

@@ -0,0 +1,179 @@
+package asynctask
+
+import (
+	"fmt"
+	"sync/atomic"
+	"time"
+
+	"github.com/splitio/go-toolkit/v3/logging"
+)
+
+// AsyncTask is a struct that wraps tasks that should run periodically and can be remotely stopped & started,
+// as well as making it's status (running/stopped) available.
+type AsyncTask struct {
+	task       func(l logging.LoggerInterface) error
+	name       string
+	running    atomic.Value
+	incoming   chan int
+	period     int
+	onInit     func(l logging.LoggerInterface) error
+	onStop     func(l logging.LoggerInterface)
+	logger     logging.LoggerInterface
+	finished   atomic.Value
+	finishChan chan struct{}
+}
+
+const (
+	taskMessageStop = iota
+	taskMessageWakeup
+)
+
+func (t *AsyncTask) _running() bool {
+	res, ok := t.running.Load().(bool)
+	if !ok {
+		t.logger.Error("Error parsing async task status flag")
+		return false
+	}
+	return res
+}
+
+// Start initiates the task. It wraps the execution in a closure guarded by a call to recover() in order
+// to prevent the main application from crashin if something goes wrong while the sdk interacts with the backend.
+func (t *AsyncTask) Start() {
+
+	if t._running() {
+		if t.logger != nil {
+			t.logger.Warning("Task %s is already running. Aborting new execution.", t.name)
+		}
+		return
+	}
+	t.running.Store(true)
+
+	go func() {
+		defer func() {
+			t.finished.Store(true)
+			t.finishChan <- struct{}{}
+		}()
+		defer func() {
+			if r := recover(); r != nil {
+				t.running.Store(false)
+				if t.logger != nil {
+					t.logger.Error(fmt.Sprintf(
+						"AsyncTask %s is panicking! Delaying execution for %d seconds (1 period)",
+						t.name,
+						t.period,
+					))
+					t.logger.Error(r)
+				}
+				time.Sleep(time.Duration(t.period) * time.Second)
+			}
+		}()
+
+		// If there's an initialization function, execute it
+		if t.onInit != nil {
+			err := t.onInit(t.logger)
+			if err != nil {
+				// If something goes wrong during initialization, abort.
+				if t.logger != nil {
+					t.logger.Error(err.Error())
+				}
+				return
+			}
+		}
+
+		// Create timeout timer
+		idleDuration := time.Second * time.Duration(t.period)
+		taskTimer := time.NewTimer(idleDuration)
+		defer taskTimer.Stop()
+
+		// Task execution
+		for t._running() {
+			// Run the wrapped task and handle the returned error if any.
+			err := t.task(t.logger)
+			if err != nil && t.logger != nil {
+				t.logger.Error(err.Error())
+			}
+
+			// Resetting timer
+			taskTimer.Reset(idleDuration)
+
+			// Wait for either a timeout or an interruption (can be a stop signal or a wake up)
+			select {
+			case msg := <-t.incoming:
+				switch msg {
+				case taskMessageStop:
+					t.running.Store(false)
+				case taskMessageWakeup:
+				}
+			case <-taskTimer.C: // Timedout
+			}
+		}
+
+		// Post-execution cleanup
+		if t.onStop != nil {
+			t.onStop(t.logger)
+		}
+	}()
+}
+
+func (t *AsyncTask) sendSignal(signal int) error {
+	select {
+	case t.incoming <- signal:
+		return nil
+	default:
+		return fmt.Errorf("Couldn't send message to task %s", t.name)
+	}
+}
+
+// Stop executes onStop hook if any, blocks until its done (if blocking = true) and prevents future executions of the task.
+func (t *AsyncTask) Stop(blocking bool) error {
+
+	if !t._running() || t.finished.Load().(bool) {
+		// Task already stopped
+		return nil
+	}
+	if err := t.sendSignal(taskMessageStop); err != nil {
+		// If the signal couldnt be sent, return error!
+		return err
+	}
+
+	if blocking {
+		// If blocking was set to true, wait until an empty strcut is pushed into the channel
+		<-t.finishChan
+	}
+	return nil
+}
+
+// WakeUp interrupts the task's sleep period and resumes execution
+func (t *AsyncTask) WakeUp() error {
+	return t.sendSignal(taskMessageWakeup)
+}
+
+// IsRunning returns true if the task is currently running
+func (t *AsyncTask) IsRunning() bool {
+	return t._running()
+}
+
+// NewAsyncTask creates a new task and returns a pointer to it
+func NewAsyncTask(
+	name string,
+	task func(l logging.LoggerInterface) error,
+	period int,
+	onInit func(l logging.LoggerInterface) error,
+	onStop func(l logging.LoggerInterface),
+	logger logging.LoggerInterface,
+) *AsyncTask {
+	t := AsyncTask{
+		name:       name,
+		task:       task,
+		period:     period,
+		onInit:     onInit,
+		onStop:     onStop,
+		logger:     logger,
+		incoming:   make(chan int, 10),
+		finishChan: make(chan struct{}, 1),
+	}
+	t.running.Store(false)
+	t.finished.Store(false)
+	return &t
+}

vendor/github.com/splitio/go-toolkit/v3/common/iterutil.go

@@ -0,0 +1,67 @@
+package common
+
+import (
+	"errors"
+	"math"
+	"time"
+)
+
+// WithAttempts executes a function N times or until no error is returned
+func WithAttempts(attempts int, main func() error) error {
+	err := errors.New("")
+	remaining := attempts
+	for err != nil && remaining > 0 {
+		remaining--
+		err = main()
+	}
+	return err
+}
+
+// WithBackoff wraps the function to add Exponential backoff
+func WithBackoff(duration time.Duration, main func() error) func() error {
+	var count time.Duration = 1
+	return func() error {
+		err := main()
+		if err != nil {
+			time.Sleep(count * duration)
+			count++
+		} else {
+			count = 0
+		}
+		return main()
+	}
+}
+
+// WithBackoffCancelling wraps the function to add Exponential backoff
+func WithBackoffCancelling(unit time.Duration, max time.Duration, main func() bool) func() {
+	cancel := make(chan struct{})
+	go func() {
+		attempts := 0
+		isDone := main()
+
+		// Create timeout timer for backoff
+		backoffTimer := time.NewTimer(MinDuration(time.Duration(math.Pow(2, float64(attempts)))*unit, max))
+		defer backoffTimer.Stop()
+
+		for !isDone {
+			attempts++
+
+			// Setting timer considerint attempts
+			backoffTimer.Reset(MinDuration(time.Duration(math.Pow(2, float64(attempts)))*unit, max))
+
+			select {
+			case <-cancel:
+				return
+			case <-backoffTimer.C: // Timedout
+				isDone = main()
+			}
+		}
+	}()
+	return func() {
+		select {
+		case cancel <- struct{}{}:
+			return
+		default:
+		}
+	}
+}

vendor/github.com/splitio/go-toolkit/v3/common/refutil.go

@@ -0,0 +1,105 @@
+package common
+
+// StringRef returns ref
+func StringRef(str string) *string {
+	return &str
+}
+
+// IntRef returns ref
+func IntRef(number int) *int {
+	return &number
+}
+
+// Int64Ref returns ref
+func Int64Ref(number int64) *int64 {
+	return &number
+}
+
+// Float64Ref returns ref
+func Float64Ref(number float64) *float64 {
+	return &number
+}
+
+// Int64Value returns value
+func Int64Value(number *int64) int64 {
+	if number == nil {
+		return 0
+	}
+	return *number
+}
+
+// IntRefOrNil returns ref
+func IntRefOrNil(number int) *int {
+	if number == 0 {
+		return nil
+	}
+	return IntRef(number)
+}
+
+// Int64RefOrNil returns ref
+func Int64RefOrNil(number int64) *int64 {
+	if number == 0 {
+		return nil
+	}
+	return Int64Ref(number)
+}
+
+// StringRefOrNil returns ref
+func StringRefOrNil(str string) *string {
+	if str == "" {
+		return nil
+	}
+	return StringRef(str)
+}
+
+// AsIntOrNil returns ref
+func AsIntOrNil(data interface{}) *int {
+	if data == nil {
+		return nil
+	}
+
+	number, ok := data.(int)
+	if !ok {
+		return nil
+	}
+	return IntRef(number)
+}
+
+// AsInt64OrNil returns ref
+func AsInt64OrNil(data interface{}) *int64 {
+	if data == nil {
+		return nil
+	}
+
+	number, ok := data.(int64)
+	if !ok {
+		return nil
+	}
+	return Int64Ref(number)
+}
+
+// AsFloat64OrNil return ref
+func AsFloat64OrNil(data interface{}) *float64 {
+	if data == nil {
+		return nil
+	}
+
+	number, ok := data.(float64)
+	if !ok {
+		return nil
+	}
+	return Float64Ref(number)
+}
+
+// AsStringOrNil returns ref
+func AsStringOrNil(data interface{}) *string {
+	if data == nil {
+		return nil
+	}
+
+	str, ok := data.(string)
+	if !ok {
+		return nil
+	}
+	return StringRef(str)
+}

vendor/github.com/splitio/go-toolkit/v3/common/sliceutil.go

@@ -0,0 +1,18 @@
+package common
+
+// Partition create partitions considering the passed amount
+func Partition(items []string, maxItems int) [][]string {
+	var splitted [][]string
+
+	for i := 0; i < len(items); i += maxItems {
+		end := i + maxItems
+
+		if end > len(items) {
+			end = len(items)
+		}
+
+		splitted = append(splitted, items[i:end])
+	}
+
+	return splitted
+}

vendor/github.com/splitio/go-toolkit/v3/common/strutil.go

@@ -0,0 +1,9 @@
+package common
+
+// StringValueOrDefault returns original value if not empty. Default otherwise.
+func StringValueOrDefault(str string, def string) string {
+	if str != "" {
+		return str
+	}
+	return def
+}

vendor/github.com/splitio/go-toolkit/v3/common/timeutil.go

@@ -0,0 +1,25 @@
+package common
+
+import "time"
+
+// MinDuration returns the min duration among them
+func MinDuration(d1, d2 time.Duration, ds ...time.Duration) time.Duration {
+	min := d1
+	for _, d := range append(ds, d2) {
+		if d < min {
+			min = d
+		}
+	}
+	return min
+}
+
+// MaxDuration returns the max duration among them
+func MaxDuration(d1, d2 time.Duration, ds ...time.Duration) time.Duration {
+	max := d1
+	for _, d := range append(ds, d2) {
+		if d > max {
+			max = d
+		}
+	}
+	return max
+}

vendor/github.com/splitio/go-toolkit/v3/datastructures/set/functions.go

@@ -0,0 +1,56 @@
+package set
+
+// Union calculates the union of two or more sets
+func Union(set1, set2 Set, sets ...Set) Set {
+	u := set1.Copy()
+	set2.Each(func(item interface{}) bool {
+		u.Add(item)
+		return true
+	})
+
+	for _, set := range sets {
+		set.Each(func(item interface{}) bool {
+			u.Add(item)
+			return true
+		})
+	}
+
+	return u
+}
+
+// Intersection calculates the intersection of two or more sets
+func Intersection(set1, set2 Set, sets ...Set) Set {
+	all := Union(set1, set2, sets...)
+	result := Union(set1, set2, sets...)
+
+	all.Each(func(item interface{}) bool {
+		if !set1.Has(item) || !set2.Has(item) {
+			result.Remove(item)
+		}
+
+		for _, set := range sets {
+			if !set.Has(item) {
+				result.Remove(item)
+			}
+		}
+		return true
+	})
+	return result
+}
+
+// Difference calculates the difference of two or more sets
+func Difference(set1, set2 Set, sets ...Set) Set {
+	s := set1.Copy()
+	s.Separate(set2)
+	for _, set := range sets {
+		s.Separate(set) // seperate is thread safe
+	}
+	return s
+}
+
+// SymmetricDifference calculates the symmetric difference of two or more sets
+func SymmetricDifference(s Set, t Set) Set {
+	u := Difference(s, t)
+	v := Difference(t, s)
+	return Union(u, v)
+}

vendor/github.com/splitio/go-toolkit/v3/datastructures/set/implementations.go

@@ -0,0 +1,355 @@
+package set
+
+import (
+	"sync"
+)
+
+var keyExists = struct{}{} // Value that indicates existance in the set for the key element
+
+// ThreadUnsafeSet structure. Container of unique items with O(1) access time. NOT THREAD SAFE
+type ThreadUnsafeSet struct {
+	set
+}
+
+// NewSet Constructs a new set from an optinal slice of items
+func NewSet(items ...interface{}) *ThreadUnsafeSet {
+	s := &ThreadUnsafeSet{}
+	s.m = make(map[interface{}]struct{})
+	s.Add(items...)
+	return s
+}
+
+// Add adds new items to the set
+func (s *ThreadUnsafeSet) Add(items ...interface{}) {
+	if len(items) == 0 {
+		return
+	}
+
+	for _, item := range items {
+		s.m[item] = keyExists
+
+	}
+}
+
+// Remove removes items from the set
+func (s *ThreadUnsafeSet) Remove(items ...interface{}) {
+	if len(items) == 0 {
+		return
+	}
+
+	for _, item := range items {
+		delete(s.m, item)
+	}
+}
+
+// Pop removes an item from the set and returns it.
+func (s *set) Pop() interface{} {
+	for item := range s.m {
+		delete(s.m, item)
+		return item
+	}
+	return nil
+}
+
+// Has returns true if the items passed are present in the set
+func (s *ThreadUnsafeSet) Has(items ...interface{}) bool {
+	// assume checked for empty item, which not exist
+	if len(items) == 0 {
+		return false
+	}
+
+	has := true
+	for _, item := range items {
+		if _, has = s.m[item]; !has {
+			break
+		}
+	}
+	return has
+}
+
+// Size returns the size of the set
+func (s *ThreadUnsafeSet) Size() int {
+	return len(s.m)
+}
+
+// Clear removes all elements from the set
+func (s *ThreadUnsafeSet) Clear() {
+	s.m = make(map[interface{}]struct{})
+}
+
+// IsEqual returns true if the received set is equal to this one
+func (s *ThreadUnsafeSet) IsEqual(t Set) bool {
+	// Force locking only if given set is threadsafe.
+	if conv, ok := t.(*ThreadSafeSet); ok {
+		conv.l.RLock()
+		defer conv.l.RUnlock()
+	}
+
+	// return false if they are no the same size
+	if sameSize := len(s.m) == t.Size(); !sameSize {
+		return false
+	}
+
+	equal := true
+	t.Each(func(item interface{}) bool {
+		_, equal = s.m[item]
+		return equal // if false, Each() will end
+	})
+
+	return equal
+}
+
+// IsSubset returns true if the passed set is a subset of this one
+func (s *ThreadUnsafeSet) IsSubset(t Set) (subset bool) {
+	subset = true
+
+	t.Each(func(item interface{}) bool {
+		_, subset = s.m[item]
+		return subset
+	})
+
+	return subset
+}
+
+// Each executes a passed function on each of the items passed.
+func (s *ThreadUnsafeSet) Each(f func(item interface{}) bool) {
+	for item := range s.m {
+		if !f(item) {
+			break
+		}
+	}
+}
+
+// List returns a slice of the items in th set
+func (s *ThreadUnsafeSet) List() []interface{} {
+	list := make([]interface{}, 0, len(s.m))
+
+	for item := range s.m {
+		list = append(list, item)
+	}
+
+	return list
+}
+
+// Copy returns a new set with a copy of the elements
+func (s *ThreadUnsafeSet) Copy() Set {
+	return NewSet(s.List()...)
+}
+
+// Merge adds all the elefements in the passed set to this one.
+func (s *ThreadUnsafeSet) Merge(t Set) {
+	t.Each(func(item interface{}) bool {
+		s.m[item] = keyExists
+		return true
+	})
+}
+
+// Separate removes all the items that are present in the passed set from this set
+func (s *ThreadUnsafeSet) Separate(t Set) {
+	s.Remove(t.List()...)
+}
+
+// IsEmpty returns true if the set has no elements
+func (s *ThreadUnsafeSet) IsEmpty() bool {
+	return s.Size() == 0
+}
+
+// IsSuperset returns true if the passed set is a supertset of this one
+func (s *ThreadUnsafeSet) IsSuperset(t Set) bool {
+	return t.IsSubset(s)
+}
+
+// ** Thread safe implementation
+
+// ThreadSafeSet is a thread safe implementation of the set data structure
+type ThreadSafeSet struct {
+	set
+	l sync.RWMutex
+}
+
+// NewThreadSafeSet instantiates a new ThreadSafeSet
+func NewThreadSafeSet(items ...interface{}) *ThreadSafeSet {
+	s := &ThreadSafeSet{}
+	s.m = make(map[interface{}]struct{})
+
+	// Ensure interface compliance
+	var _ Set = s
+
+	s.Add(items...)
+	return s
+}
+
+// Add adds a new element to the set
+func (s *ThreadSafeSet) Add(items ...interface{}) {
+	if len(items) == 0 {
+		return
+	}
+
+	s.l.Lock()
+	defer s.l.Unlock()
+
+	for _, item := range items {
+		s.m[item] = keyExists
+	}
+}
+
+// Remove deletes an elemenet from the set.
+func (s *ThreadSafeSet) Remove(items ...interface{}) {
+	if len(items) == 0 {
+		return
+	}
+
+	s.l.Lock()
+	defer s.l.Unlock()
+
+	for _, item := range items {
+		delete(s.m, item)
+	}
+}
+
+// Pop removes an element from the set and returns it
+func (s *ThreadSafeSet) Pop() interface{} {
+	s.l.RLock()
+	for item := range s.m {
+		s.l.RUnlock()
+		s.l.Lock()
+		delete(s.m, item)
+		s.l.Unlock()
+		return item
+	}
+	s.l.RUnlock()
+	return nil
+}
+
+// Has returns true if the element passed is in the set
+func (s *ThreadSafeSet) Has(items ...interface{}) bool {
+	// assume checked for empty item, which not exist
+	if len(items) == 0 {
+		return false
+	}
+
+	s.l.RLock()
+	defer s.l.RUnlock()
+
+	has := true
+	for _, item := range items {
+		if _, has = s.m[item]; !has {
+			break
+		}
+	}
+	return has
+}
+
+// Size returns the number of elements in the set
+func (s *ThreadSafeSet) Size() int {
+	s.l.RLock()
+	defer s.l.RUnlock()
+
+	l := len(s.m)
+	return l
+}
+
+// Clear removes all the elements in the set
+func (s *ThreadSafeSet) Clear() {
+	s.l.Lock()
+	defer s.l.Unlock()
+
+	s.m = make(map[interface{}]struct{})
+}
+
+// IsEqual returns true if the set contains the same elements as the passed one
+func (s *ThreadSafeSet) IsEqual(t Set) bool {
+	s.l.RLock()
+	defer s.l.RUnlock()
+
+	// Force locking only if given set is threadsafe.
+	if conv, ok := t.(*ThreadSafeSet); ok {
+		conv.l.RLock()
+		defer conv.l.RUnlock()
+	}
+
+	// return false if they are no the same size
+	if sameSize := len(s.m) == t.Size(); !sameSize {
+		return false
+	}
+
+	equal := true
+	t.Each(func(item interface{}) bool {
+		_, equal = s.m[item]
+		return equal // if false, Each() will end
+	})
+
+	return equal
+}
+
+// IsSubset returns true if the passed set is a subset of this one
+func (s *ThreadSafeSet) IsSubset(t Set) (subset bool) {
+	s.l.RLock()
+	defer s.l.RUnlock()
+
+	subset = true
+
+	t.Each(func(item interface{}) bool {
+		_, subset = s.m[item]
+		return subset
+	})
+
+	return
+}
+
+// Each executes the passed function on each item from the set
+func (s *ThreadSafeSet) Each(f func(item interface{}) bool) {
+	s.l.RLock()
+	defer s.l.RUnlock()
+
+	for item := range s.m {
+		if !f(item) {
+			break
+		}
+	}
+}
+
+// List returns a list with all the elements of the set
+func (s *ThreadSafeSet) List() []interface{} {
+	s.l.RLock()
+	defer s.l.RUnlock()
+
+	list := make([]interface{}, 0, len(s.m))
+
+	for item := range s.m {
+		list = append(list, item)
+	}
+
+	return list
+}
+
+// Merge adds all the elements of the passed set into this one
+func (s *ThreadSafeSet) Merge(t Set) {
+	s.l.Lock()
+	defer s.l.Unlock()
+
+	t.Each(func(item interface{}) bool {
+		s.m[item] = keyExists
+		return true
+	})
+}
+
+// Copy returns a copy of the this thread
+func (s *ThreadSafeSet) Copy() Set {
+	return NewThreadSafeSet(s.List()...)
+}
+
+// Separate removes all the items that are present in the passed set from this set
+func (s *ThreadSafeSet) Separate(t Set) {
+	s.Remove(t.List()...)
+}
+
+// IsEmpty returns true if the set has no elements
+func (s *ThreadSafeSet) IsEmpty() bool {
+	return s.Size() == 0
+}
+
+// IsSuperset returns true if the passed set is a supertset of this one
+func (s *ThreadSafeSet) IsSuperset(t Set) bool {
+	return t.IsSubset(s)
+}

vendor/github.com/splitio/go-toolkit/v3/datastructures/set/set.go

@@ -0,0 +1,24 @@
+package set
+
+// Set interface shared between Thread-Safe and Thread-Unsafe implementations
+type Set interface {
+	Add(items ...interface{})
+	Remove(items ...interface{})
+	Pop() interface{}
+	Has(items ...interface{}) bool
+	Size() int
+	Clear()
+	IsEmpty() bool
+	IsEqual(s Set) bool
+	IsSubset(s Set) bool
+	IsSuperset(s Set) bool
+	Each(func(interface{}) bool)
+	List() []interface{}
+	Copy() Set
+	Merge(s Set)
+	Separate(t Set)
+}
+
+type set struct {
+	m map[interface{}]struct{}
+}

vendor/github.com/splitio/go-toolkit/v3/injection/container.go

@@ -0,0 +1,47 @@
+package injection
+
+import (
+	"reflect"
+	"sync"
+)
+
+// NewContext return an instance of Context
+func NewContext() *Context {
+	return &Context{container: make(map[string]interface{})}
+}
+
+// Context of dependencies to be injected as context
+type Context struct {
+	container map[string]interface{}
+	mx        sync.Mutex
+}
+
+// AddDependency adds a dependency to the container
+func (c *Context) AddDependency(key string, d interface{}) {
+	c.mx.Lock()
+	c.container[key] = d
+	c.mx.Unlock()
+
+}
+
+// Dependency returns an object given a key
+func (c *Context) Dependency(key string) interface{} {
+	c.mx.Lock()
+	defer c.mx.Unlock()
+
+	return c.container[key]
+}
+
+// Inject add the Context instance as dependency
+func (c *Context) Inject(o interface{}) {
+	rv := reflect.ValueOf(c)
+	reflectedContext := reflect.ValueOf(o).Elem()
+	typeOfT := rv.Type()
+
+	for i := 0; i < reflectedContext.NumField(); i++ {
+		f := reflectedContext.Field(i)
+		if f.Type().String() == typeOfT.String() {
+			reflectedContext.Field(i).Set(rv)
+		}
+	}
+}

vendor/github.com/splitio/go-toolkit/v3/logging/functions.go

@@ -0,0 +1,33 @@
+package logging
+
+import (
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+)
+
+// ObfuscateAPIKey obfucate part of api key
+func ObfuscateAPIKey(apikey string) string {
+	obfuscationIndex := 80
+
+	total := len(apikey)
+	charsToObfuscate := obfuscationIndex * total / 100
+	toShow := (total - charsToObfuscate) / 2
+
+	return strings.Join([]string{apikey[:toShow], apikey[len(apikey)-toShow:]}, "...")
+}
+
+// ObfuscateHTTPHeader obfuscates sensitive data into headers
+func ObfuscateHTTPHeader(headers http.Header) string {
+	var re = regexp.MustCompile(`Authorization:\[Bearer ([0-9|a-z|A-Z|\s]*)\]`)
+	var str = fmt.Sprint(headers)
+	match := re.FindStringSubmatch(str)
+
+	if len(match) == 2 {
+		str = strings.Replace(str, match[1], ObfuscateAPIKey(match[1]), 1)
+		return fmt.Sprint("[REQUEST_HEADERS]", str, "[END_REQUEST_HEADERS]")
+	}
+
+	return str
+}

vendor/github.com/splitio/go-toolkit/v3/logging/interface.go

@@ -0,0 +1,12 @@
+package logging
+
+// LoggerInterface ...
+// If a custom logger object is to be used, it should comply with the following
+// interface. (Standard go-lang library log.Logger.Println method signature)
+type LoggerInterface interface {
+	Error(msg ...interface{})
+	Warning(msg ...interface{})
+	Info(msg ...interface{})
+	Debug(msg ...interface{})
+	Verbose(msg ...interface{})
+}

vendor/github.com/splitio/go-toolkit/v3/logging/levels.go

@@ -0,0 +1,93 @@
+package logging
+
+import (
+	"math"
+)
+
+// Standard values
+const (
+	// Discard 0 value, so when can use it as "the lack of a logging level"
+	_ = iota
+
+	// LevelError log level
+	LevelError
+
+	// LevelWarning log level
+	LevelWarning
+
+	// LevelInfo log level
+	LevelInfo
+
+	// LevelDebug log level
+	LevelDebug
+
+	// LevelVerbose log level
+	LevelVerbose
+)
+
+// Special values
+const (
+	// LevelNone implies that NOTHING will be logged, not even errors
+	LevelNone = math.MinInt32
+
+	// LevelAll implies that All logging levels will be recorded
+	LevelAll = math.MaxInt32
+)
+
+// LevelFilteredLoggerWrapper forwards log message to delegate if level is set higher than incoming message
+type LevelFilteredLoggerWrapper struct {
+	level    int
+	delegate LoggerInterface
+}
+
+// Error forwards error logging messages
+func (l *LevelFilteredLoggerWrapper) Error(is ...interface{}) {
+	if l.level >= LevelError {
+		l.delegate.Error(is...)
+	}
+}
+
+// Warning forwards warning logging messages
+func (l *LevelFilteredLoggerWrapper) Warning(is ...interface{}) {
+	if l.level >= LevelWarning {
+		l.delegate.Warning(is...)
+	}
+}
+
+// Info forwards info logging messages
+func (l *LevelFilteredLoggerWrapper) Info(is ...interface{}) {
+	if l.level >= LevelInfo {
+		l.delegate.Info(is...)
+	}
+}
+
+// Debug forwards debug logging messages
+func (l *LevelFilteredLoggerWrapper) Debug(is ...interface{}) {
+	if l.level >= LevelDebug {
+		l.delegate.Debug(is...)
+	}
+}
+
+// Verbose forwards verbose logging messages
+func (l *LevelFilteredLoggerWrapper) Verbose(is ...interface{}) {
+	if l.level >= LevelVerbose {
+		l.delegate.Verbose(is...)
+	}
+}
+
+var levels map[string]int = map[string]int{
+	"ERROR":   LevelError,
+	"WARNING": LevelWarning,
+	"INFO":    LevelInfo,
+	"DEBUG":   LevelDebug,
+	"VERBOSE": LevelVerbose,
+}
+
+// Level gets current level
+func Level(level string) int {
+	l, ok := levels[level]
+	if !ok {
+		panic("Invalid log level " + level)
+	}
+	return l
+}

vendor/github.com/splitio/go-toolkit/v3/logging/logging.go

@@ -0,0 +1,129 @@
+// Package logging ...
+// Handles logging within the SDK
+package logging
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"os"
+)
+
+const (
+	skipStackFrameBase = 3 // How many stack frames to skip when logging filename
+)
+
+// LoggerOptions ...
+// Struct that must be passed to the NewLogger constructor to setup a logger
+// CommonWriter and ErrorWriter can be <nil>. In that case they'll default to os.Stdout
+type LoggerOptions struct {
+	LogLevel            int
+	ErrorWriter         io.Writer
+	WarningWriter       io.Writer
+	InfoWriter          io.Writer
+	DebugWriter         io.Writer
+	VerboseWriter       io.Writer
+	StandardLoggerFlags int
+	Prefix              string
+	ExtraFramesToSkip   int
+}
+
+// Logger struct. Encapsulates four different loggers, each for a different "level",
+// and provides Error, Debug, Warning and Info functions, that will forward a message
+// to the appropriate logger.
+type Logger struct {
+	debugLogger   log.Logger
+	infoLogger    log.Logger
+	warningLogger log.Logger
+	errorLogger   log.Logger
+	verboseLogger log.Logger
+	framesToSkip  int
+}
+
+// Verbose logs a message with Debug level
+func (l *Logger) Verbose(msg ...interface{}) {
+	l.verboseLogger.Output(l.framesToSkip, fmt.Sprintln(msg...))
+}
+
+// Debug logs a message with Debug level
+func (l *Logger) Debug(msg ...interface{}) {
+	l.debugLogger.Output(l.framesToSkip, fmt.Sprintln(msg...))
+}
+
+// Info logs a message with Info level
+func (l *Logger) Info(msg ...interface{}) {
+	l.infoLogger.Output(l.framesToSkip, fmt.Sprintln(msg...))
+}
+
+// Warning logs a message with Warning level
+func (l *Logger) Warning(msg ...interface{}) {
+	l.warningLogger.Output(l.framesToSkip, fmt.Sprintln(msg...))
+}
+
+// Error logs a message with Error level
+func (l *Logger) Error(msg ...interface{}) {
+	l.errorLogger.Output(l.framesToSkip, fmt.Sprintln(msg...))
+}
+
+func normalizeOptions(options *LoggerOptions) *LoggerOptions {
+	var toRet *LoggerOptions
+	if options == nil {
+		toRet = &LoggerOptions{}
+	} else {
+		toRet = options
+	}
+
+	if toRet.DebugWriter == nil {
+		toRet.DebugWriter = os.Stdout
+	}
+
+	if toRet.ErrorWriter == nil {
+		toRet.ErrorWriter = os.Stdout
+	}
+
+	if toRet.InfoWriter == nil {
+		toRet.InfoWriter = os.Stdout
+	}
+
+	if toRet.VerboseWriter == nil {
+		toRet.VerboseWriter = os.Stdout
+	}
+
+	if toRet.WarningWriter == nil {
+		toRet.WarningWriter = os.Stdout
+	}
+
+	if toRet.StandardLoggerFlags == 0 {
+		toRet.StandardLoggerFlags = log.Ldate | log.Ltime
+	}
+
+	switch toRet.LogLevel {
+	case LevelAll, LevelDebug, LevelError, LevelInfo, LevelNone, LevelVerbose, LevelWarning:
+	default:
+		toRet.LogLevel = LevelError
+	}
+	return toRet
+}
+
+// NewLogger instantiates a new Logger instance. Requires a pointer to a LoggerOptions struct to be passed.
+func NewLogger(options *LoggerOptions) LoggerInterface {
+
+	options = normalizeOptions(options)
+	prefix := ""
+	if options.Prefix != "" {
+		prefix = fmt.Sprintf("%s - ", options.Prefix)
+	}
+	logger := &Logger{
+		debugLogger:   *log.New(options.DebugWriter, fmt.Sprintf("%sDEBUG - ", prefix), options.StandardLoggerFlags),
+		infoLogger:    *log.New(options.InfoWriter, fmt.Sprintf("%sINFO - ", prefix), options.StandardLoggerFlags),
+		warningLogger: *log.New(options.WarningWriter, fmt.Sprintf("%sWARNING - ", prefix), options.StandardLoggerFlags),
+		errorLogger:   *log.New(options.ErrorWriter, fmt.Sprintf("%sERROR - ", prefix), options.StandardLoggerFlags),
+		verboseLogger: *log.New(options.VerboseWriter, fmt.Sprintf("%sVERBOSE - ", prefix), options.StandardLoggerFlags),
+		framesToSkip:  3 + options.ExtraFramesToSkip,
+	}
+
+	return &LevelFilteredLoggerWrapper{
+		delegate: logger,
+		level:    options.LogLevel,
+	}
+}

vendor/github.com/splitio/go-toolkit/v3/logging/rotate.go

@@ -0,0 +1,106 @@
+package logging
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"sync"
+)
+
+// FileRotateOptions struct to configure FileRotate
+type FileRotateOptions struct {
+	MaxBytes    int64
+	BackupCount int
+	Path        string
+}
+
+// FileRotate rotates a log file at MaxBytes
+type FileRotate struct {
+	fl      *os.File
+	fm      *sync.Mutex
+	options *FileRotateOptions
+}
+
+// NewFileRotate returns a pointer to a FileRotate instance
+func NewFileRotate(opt *FileRotateOptions) (*FileRotate, error) {
+
+	fileWriter, err := os.OpenFile(opt.Path, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
+	if err != nil {
+		return nil, err
+	}
+
+	fl := &FileRotate{fl: fileWriter, fm: &sync.Mutex{}, options: opt}
+	return fl, nil
+}
+
+func (f *FileRotate) shouldRotate(bytesToAdd int64) bool {
+	fi, err := f.fl.Stat()
+	if err != nil {
+		fmt.Println("Error getting stats of file")
+		return false
+	}
+
+	if fi.Size()+bytesToAdd >= f.options.MaxBytes {
+		return true
+	}
+
+	return false
+}
+
+func (f *FileRotate) rotate() error {
+
+	f.fl.Close()
+
+	for i := f.options.BackupCount - 1; i >= 0; i-- {
+		var currentLog string
+		if i == 0 {
+			currentLog = f.options.Path
+		} else {
+			currentLog = f.options.Path + "." + strconv.Itoa(i)
+		}
+
+		if _, err := os.Stat(currentLog); err == nil {
+			rotateLog := f.options.Path + "." + strconv.Itoa(i+1)
+			err := os.Rename(currentLog, rotateLog)
+			if err != nil {
+				fmt.Printf("Error rotating log file: %s \n", err.Error())
+				return err
+			}
+		}
+
+	}
+
+	var err error
+	f.fl, err = os.OpenFile(f.options.Path, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
+	if err != nil {
+		fmt.Printf("Error reopening log file: %s \n", err.Error())
+		return err
+	}
+
+	return nil
+}
+
+func (f *FileRotate) write(p []byte) (n int, err error) {
+	f.fm.Lock()
+	if f.shouldRotate(int64(len(p))) {
+		f.rotate()
+	}
+
+	n, err = f.fl.Write(p)
+	f.fm.Unlock()
+
+	if err != nil {
+		fmt.Println("Error writing in rotated log file", f.options.Path)
+		return n, err
+	}
+
+	return n, nil
+}
+
+// Write writes async the log message
+func (f *FileRotate) Write(p []byte) (n int, err error) {
+	dst := make([]byte, len(p))
+	copy(dst, p)
+	go f.write(dst)
+	return len(p), nil
+}

vendor/github.com/splitio/go-toolkit/v3/nethelpers/ip.go

@@ -0,0 +1,44 @@
+package nethelpers
+
+import (
+	"errors"
+	"net"
+)
+
+// ExternalIP returns the IP address of the host
+func ExternalIP() (string, error) {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return "", err
+	}
+	for _, iface := range ifaces {
+		if iface.Flags&net.FlagUp == 0 {
+			continue // interface down
+		}
+		if iface.Flags&net.FlagLoopback != 0 {
+			continue // loopback interface
+		}
+		addrs, err := iface.Addrs()
+		if err != nil {
+			return "", err
+		}
+		for _, addr := range addrs {
+			var ip net.IP
+			switch v := addr.(type) {
+			case *net.IPNet:
+				ip = v.IP
+			case *net.IPAddr:
+				ip = v.IP
+			}
+			if ip == nil || ip.IsLoopback() {
+				continue
+			}
+			ip = ip.To4()
+			if ip == nil {
+				continue // not an ipv4 address
+			}
+			return ip.String(), nil
+		}
+	}
+	return "", errors.New("Could not determine IP Address")
+}

vendor/github.com/splitio/go-toolkit/v3/provisional/hashing/murmur128.go

@@ -0,0 +1,231 @@
+package hashing
+
+// Implementation borrowed from https://github.com/spaolacci/murmur3,
+// distributed under BSD-3 license.
+
+import (
+	//"encoding/binary"
+	"hash"
+	"math/bits"
+	"unsafe"
+)
+
+const (
+	c1_128 = 0x87c37b91114253d5
+	c2_128 = 0x4cf5ad432745937f
+)
+
+// Hash128 represents a 128-bit hasher
+// Hack: the standard api doesn't define any Hash128 interface.
+type Hash128 interface {
+	hash.Hash
+	Sum128() (uint64, uint64)
+}
+
+// digest128 represents a partial evaluation of a 128 bites hash.
+type digest128 struct {
+	clen int      // Digested input cumulative length.
+	tail []byte   // 0 to Size()-1 bytes view of `buf'.
+	buf  [16]byte // Expected (but not required) to be Size() large.
+	seed uint32   // Seed for initializing the hash.
+	h1   uint64   // Unfinalized running hash part 1.
+	h2   uint64   // Unfinalized running hash part 2.
+}
+
+// New128 returns a 128-bit hasher
+func New128() Hash128 { return New128WithSeed(0) }
+
+// New128WithSeed returns a 128-bit hasher set with explicit seed value
+func New128WithSeed(seed uint32) Hash128 {
+	d := new(digest128)
+	d.seed = seed
+	d.Reset()
+	return d
+}
+
+func (d *digest128) BlockSize() int { return 1 }
+
+func (d *digest128) Write(p []byte) (n int, err error) {
+	n = len(p)
+	d.clen += n
+
+	if len(d.tail) > 0 {
+		// Stick back pending bytes.
+		nfree := d.Size() - len(d.tail) // nfree ∈ [1, d.Size()-1].
+		if nfree < len(p) {
+			// One full block can be formed.
+			block := append(d.tail, p[:nfree]...)
+			p = p[nfree:]
+			_ = d.bmix(block) // No tail.
+		} else {
+			// Tail's buf is large enough to prevent reallocs.
+			p = append(d.tail, p...)
+		}
+	}
+
+	d.tail = d.bmix(p)
+
+	// Keep own copy of the 0 to Size()-1 pending bytes.
+	nn := copy(d.buf[:], d.tail)
+	d.tail = d.buf[:nn]
+
+	return n, nil
+}
+
+func (d *digest128) Reset() {
+	d.clen = 0
+	d.tail = nil
+	d.reset()
+}
+
+func (d *digest128) Size() int { return 16 }
+
+func (d *digest128) reset() { d.h1, d.h2 = uint64(d.seed), uint64(d.seed) }
+
+func (d *digest128) Sum(b []byte) []byte {
+	h1, h2 := d.Sum128()
+	return append(b,
+		byte(h1>>56), byte(h1>>48), byte(h1>>40), byte(h1>>32),
+		byte(h1>>24), byte(h1>>16), byte(h1>>8), byte(h1),
+
+		byte(h2>>56), byte(h2>>48), byte(h2>>40), byte(h2>>32),
+		byte(h2>>24), byte(h2>>16), byte(h2>>8), byte(h2),
+	)
+}
+
+func (d *digest128) bmix(p []byte) (tail []byte) {
+	h1, h2 := d.h1, d.h2
+
+	nblocks := len(p) / 16
+	for i := 0; i < nblocks; i++ {
+		t := (*[2]uint64)(unsafe.Pointer(&p[i*16]))
+		k1, k2 := t[0], t[1]
+
+		k1 *= c1_128
+		k1 = bits.RotateLeft64(k1, 31)
+		k1 *= c2_128
+		h1 ^= k1
+
+		h1 = bits.RotateLeft64(h1, 27)
+		h1 += h2
+		h1 = h1*5 + 0x52dce729
+
+		k2 *= c2_128
+		k2 = bits.RotateLeft64(k2, 33)
+		k2 *= c1_128
+		h2 ^= k2
+
+		h2 = bits.RotateLeft64(h2, 31)
+		h2 += h1
+		h2 = h2*5 + 0x38495ab5
+	}
+	d.h1, d.h2 = h1, h2
+	return p[nblocks*d.Size():]
+}
+
+func (d *digest128) Sum128() (h1, h2 uint64) {
+
+	h1, h2 = d.h1, d.h2
+
+	var k1, k2 uint64
+	switch len(d.tail) & 15 {
+	case 15:
+		k2 ^= uint64(d.tail[14]) << 48
+		fallthrough
+	case 14:
+		k2 ^= uint64(d.tail[13]) << 40
+		fallthrough
+	case 13:
+		k2 ^= uint64(d.tail[12]) << 32
+		fallthrough
+	case 12:
+		k2 ^= uint64(d.tail[11]) << 24
+		fallthrough
+	case 11:
+		k2 ^= uint64(d.tail[10]) << 16
+		fallthrough
+	case 10:
+		k2 ^= uint64(d.tail[9]) << 8
+		fallthrough
+	case 9:
+		k2 ^= uint64(d.tail[8]) << 0
+
+		k2 *= c2_128
+		k2 = bits.RotateLeft64(k2, 33)
+		k2 *= c1_128
+		h2 ^= k2
+
+		fallthrough
+
+	case 8:
+		k1 ^= uint64(d.tail[7]) << 56
+		fallthrough
+	case 7:
+		k1 ^= uint64(d.tail[6]) << 48
+		fallthrough
+	case 6:
+		k1 ^= uint64(d.tail[5]) << 40
+		fallthrough
+	case 5:
+		k1 ^= uint64(d.tail[4]) << 32
+		fallthrough
+	case 4:
+		k1 ^= uint64(d.tail[3]) << 24
+		fallthrough
+	case 3:
+		k1 ^= uint64(d.tail[2]) << 16
+		fallthrough
+	case 2:
+		k1 ^= uint64(d.tail[1]) << 8
+		fallthrough
+	case 1:
+		k1 ^= uint64(d.tail[0]) << 0
+		k1 *= c1_128
+		k1 = bits.RotateLeft64(k1, 31)
+		k1 *= c2_128
+		h1 ^= k1
+	}
+
+	h1 ^= uint64(d.clen)
+	h2 ^= uint64(d.clen)
+
+	h1 += h2
+	h2 += h1
+
+	h1 = fmix64(h1)
+	h2 = fmix64(h2)
+
+	h1 += h2
+	h2 += h1
+
+	return h1, h2
+}
+
+func fmix64(k uint64) uint64 {
+	k ^= k >> 33
+	k *= 0xff51afd7ed558ccd
+	k ^= k >> 33
+	k *= 0xc4ceb9fe1a85ec53
+	k ^= k >> 33
+	return k
+}
+
+// Sum128 returns the MurmurHash3 sum of data. It is equivalent to the
+// following sequence (without the extra burden and the extra allocation):
+//     hasher := New128()
+//     hasher.Write(data)
+//     return hasher.Sum128()
+func Sum128(data []byte) (h1 uint64, h2 uint64) { return Sum128WithSeed(data, 0) }
+
+// Sum128WithSeed returns the MurmurHash3 sum of data. It is equivalent to the
+// following sequence (without the extra burden and the extra allocation):
+//     hasher := New128WithSeed(seed)
+//     hasher.Write(data)
+//     return hasher.Sum128()
+func Sum128WithSeed(data []byte, seed uint32) (h1 uint64, h2 uint64) {
+	d := digest128{h1: uint64(seed), h2: uint64(seed)}
+	d.seed = seed
+	d.tail = d.bmix(data)
+	d.clen = len(data)
+	return d.Sum128()
+}

vendor/github.com/splitio/go-toolkit/v3/provisional/int64cache/cache.go

@@ -0,0 +1,91 @@
+package int64cache
+
+import (
+	"container/list"
+	"fmt"
+	"sync"
+)
+
+// Int64Cache is an in-memory TTL & LRU cache
+type Int64Cache interface {
+	Get(key int64) (int64, error)
+	Set(key int64, value int64) error
+}
+
+// Impl implements the LocalCache interface
+type Impl struct {
+	maxLen int
+	items  map[int64]*list.Element
+	lru    *list.List
+	mutex  sync.Mutex
+}
+
+type entry struct {
+	key   int64
+	value int64
+}
+
+// Get retrieves an item if exist, nil + an error otherwise
+func (c *Impl) Get(key int64) (int64, error) {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+	node, ok := c.items[key]
+	if !ok {
+		return 0, &Miss{}
+	}
+
+	entry, ok := node.Value.(entry)
+	if !ok {
+		return 0, fmt.Errorf("Invalid data in cache for key %d", key)
+	}
+
+	c.lru.MoveToFront(node)
+	return entry.value, nil
+}
+
+// Set adds a new item. Since the cache being full results in removing the LRU element, this method never fails.
+func (c *Impl) Set(key int64, value int64) error {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+	if node, ok := c.items[key]; ok {
+		c.lru.MoveToFront(node)
+		node.Value = entry{key: key, value: value}
+	} else {
+		// Drop the LRU item on the list before adding a new one.
+		if c.lru.Len() == c.maxLen {
+			entry, ok := c.lru.Back().Value.(entry)
+			if !ok {
+				return fmt.Errorf("Invalid data in list for key %d", key)
+			}
+			key := entry.key
+			delete(c.items, key)
+			c.lru.Remove(c.lru.Back())
+		}
+
+		ptr := c.lru.PushFront(entry{key: key, value: value})
+		c.items[key] = ptr
+	}
+	return nil
+}
+
+// NewInt64Cache returns a new LocalCache instance of the specified size and TTL
+func NewInt64Cache(maxSize int) (*Impl, error) {
+	if maxSize <= 0 {
+		return nil, fmt.Errorf("Cache size should be > 0. Is: %d", maxSize)
+	}
+
+	return &Impl{
+		maxLen: maxSize,
+		lru:    new(list.List),
+		items:  make(map[int64]*list.Element, maxSize),
+	}, nil
+}
+
+// Miss is a special error indicating the key was not found in the cache
+type Miss struct {
+	Key int64
+}
+
+func (m *Miss) Error() string {
+	return fmt.Sprintf("key %d not found in cache", m.Key)
+}

vendor/github.com/splitio/go-toolkit/v3/queuecache/cache.go

@@ -0,0 +1,127 @@
+package queuecache
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"sync"
+)
+
+// RefillError struct to be returned when the refill function panics
+type RefillError struct {
+	OriginalPanic interface{}
+}
+
+func (e *RefillError) Error() string {
+	return "Supplied refilling function panicked. See `.OriginalPanic` property to get panicked content"
+}
+
+// MessagesDroppedError is the Error to be returned when messages fail to be added to the queue.
+type MessagesDroppedError struct {
+	MessagesDropped int
+}
+
+func (e *MessagesDroppedError) Error() string {
+	return fmt.Sprintf(
+		"%d messages were dropped. Please report this error as it's most likely a bug in the library",
+		e.MessagesDropped,
+	)
+}
+
+// InMemoryQueueCacheOverlay offers an in-memory queue that gets re-populated whenever it runs out of items
+type InMemoryQueueCacheOverlay struct {
+	maxSize      int
+	writeCursor  int
+	readCursor   int
+	queue        []interface{}
+	lock         sync.Mutex
+	refillCustom func(count int) ([]interface{}, error)
+}
+
+// New creates a new InMemoryQueueCacheOverlay
+func New(maxSize int, refillFunc func(count int) ([]interface{}, error)) *InMemoryQueueCacheOverlay {
+	return &InMemoryQueueCacheOverlay{
+		queue:        make([]interface{}, maxSize),
+		maxSize:      maxSize,
+		writeCursor:  0,
+		readCursor:   0,
+		refillCustom: refillFunc,
+	}
+}
+
+// Count returns the number of cached items
+func (i *InMemoryQueueCacheOverlay) Count() int {
+	if i.writeCursor == i.readCursor {
+		return 0
+	} else if i.writeCursor > i.readCursor {
+		return i.writeCursor - i.readCursor
+	}
+	return i.maxSize - (i.readCursor - i.writeCursor)
+}
+
+func (i *InMemoryQueueCacheOverlay) write(elem interface{}) error {
+	if ((i.writeCursor + 1) % i.maxSize) == i.readCursor {
+		return errors.New("QUEUE_FULL")
+	}
+
+	i.queue[i.writeCursor] = elem
+	i.writeCursor = (i.writeCursor + 1) % i.maxSize
+	return nil
+}
+
+func (i *InMemoryQueueCacheOverlay) read() (interface{}, error) {
+	if i.readCursor == i.writeCursor {
+		return nil, errors.New("QUEUE_EMPTY")
+	}
+
+	toReturn := i.queue[i.readCursor]
+	i.readCursor = (i.readCursor + 1) % i.maxSize
+	return toReturn, nil
+}
+
+func (i *InMemoryQueueCacheOverlay) refillWrapper(count int) (result []interface{}, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			result = nil
+			err = &RefillError{OriginalPanic: r}
+		}
+	}()
+
+	return i.refillCustom(count)
+
+}
+
+// Fetch items (will re-populate if necessary)
+func (i *InMemoryQueueCacheOverlay) Fetch(requestedCount int) ([]interface{}, error) {
+	defer i.lock.Unlock()
+	i.lock.Lock()
+
+	dropped := 0
+	if i.Count() < requestedCount {
+		toAdd, err := i.refillWrapper(i.maxSize - i.Count() - 1)
+		if err != nil {
+			return nil, err
+		}
+		for _, item := range toAdd {
+			err = i.write(item)
+			if err != nil {
+				dropped++
+			}
+		}
+	}
+
+	toReturn := make([]interface{}, int(math.Min(float64(requestedCount), float64(i.Count()))))
+	for index := 0; index < len(toReturn); index++ {
+		elem, err := i.read()
+		if err != nil {
+			return toReturn[0:index], nil
+		}
+		toReturn[index] = elem
+	}
+
+	if dropped > 0 {
+		return toReturn, &MessagesDroppedError{MessagesDropped: dropped}
+	}
+	return toReturn, nil
+
+}

vendor/github.com/splitio/go-toolkit/v3/redis/helpers/helpers.go

@@ -0,0 +1,23 @@
+package helpers
+
+import (
+	"fmt"
+
+	"github.com/splitio/go-toolkit/v3/redis"
+)
+
+const (
+	pong = "PONG"
+)
+
+// EnsureConnected pings redis
+func EnsureConnected(client redis.Client) {
+	res := client.Ping()
+	if res.Err() != nil {
+		panic(fmt.Sprintf("Couldn't connect to redis: %s", res.Err()))
+	}
+
+	if res.String() != pong {
+		panic(fmt.Sprintf("Invalid redis ping response when connecting: %s", res.String()))
+	}
+}

vendor/github.com/splitio/go-toolkit/v3/redis/prefixedclient.go

@@ -0,0 +1,160 @@
+package redis
+
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+// PrefixedRedisClient struct
+type PrefixedRedisClient struct {
+	Prefix string
+	Client Client
+}
+
+// withPrefix adds a prefix to the key if the prefix supplied has a length greater than 0
+func (p *PrefixedRedisClient) withPrefix(key string) string {
+	if len(p.Prefix) > 0 {
+		return fmt.Sprintf("%s.%s", p.Prefix, key)
+	}
+	return key
+}
+
+// withoutPrefix removes the prefix from a key if the prefix has a length greater than 0
+func (p *PrefixedRedisClient) withoutPrefix(key string) string {
+	if len(p.Prefix) > 0 {
+		return strings.Replace(key, fmt.Sprintf("%s.", p.Prefix), "", 1)
+	}
+	return key
+}
+
+// Get wraps around redis get method by adding prefix and returning string and error directly
+func (p *PrefixedRedisClient) Get(key string) (string, error) {
+	return p.Client.Get(p.withPrefix(key)).ResultString()
+}
+
+// Set wraps around redis get method by adding prefix and returning error directly
+func (p *PrefixedRedisClient) Set(key string, value interface{}, expiration time.Duration) error {
+	return p.Client.Set(p.withPrefix(key), value, expiration).Err()
+}
+
+// Keys wraps around redis keys method by adding prefix and returning []string and error directly
+func (p *PrefixedRedisClient) Keys(pattern string) ([]string, error) {
+	keys, err := p.Client.Keys(p.withPrefix(pattern)).Multi()
+	if err != nil {
+		return nil, err
+	}
+
+	woPrefix := make([]string, len(keys))
+	for index, key := range keys {
+		woPrefix[index] = p.withoutPrefix(key)
+	}
+	return woPrefix, nil
+
+}
+
+// Del wraps around redis del method by adding prefix and returning int64 and error directly
+func (p *PrefixedRedisClient) Del(keys ...string) (int64, error) {
+	prefixedKeys := make([]string, len(keys))
+	for i, k := range keys {
+		prefixedKeys[i] = p.withPrefix(k)
+	}
+	return p.Client.Del(prefixedKeys...).Result()
+}
+
+// SMembers returns a slice with all the members of a set
+func (p *PrefixedRedisClient) SMembers(key string) ([]string, error) {
+	return p.Client.SMembers(p.withPrefix(key)).Multi()
+}
+
+// SIsMember returns true if members is in the set
+func (p *PrefixedRedisClient) SIsMember(key string, member interface{}) bool {
+	return p.Client.SIsMember(p.withPrefix(key), member).Bool()
+}
+
+// SAdd adds new members to a set
+func (p *PrefixedRedisClient) SAdd(key string, members ...interface{}) (int64, error) {
+	return p.Client.SAdd(p.withPrefix(key), members...).Result()
+}
+
+// SRem removes members from a set
+func (p *PrefixedRedisClient) SRem(key string, members ...interface{}) (int64, error) {
+	return p.Client.SRem(p.withPrefix(key), members...).Result()
+}
+
+// Exists returns true if a key exists in redis
+func (p *PrefixedRedisClient) Exists(keys ...string) (int64, error) {
+	prefixedKeys := make([]string, len(keys))
+	for i, k := range keys {
+		prefixedKeys[i] = p.withPrefix(k)
+	}
+	val, err := p.Client.Exists(prefixedKeys...).Result()
+	return val, err
+}
+
+// Incr increments a key. Sets it in one if it doesn't exist
+func (p *PrefixedRedisClient) Incr(key string) (int64, error) {
+	return p.Client.Incr(p.withPrefix(key)).Result()
+}
+
+// Decr increments a key. Sets it in one if it doesn't exist
+func (p *PrefixedRedisClient) Decr(key string) (int64, error) {
+	return p.Client.Decr(p.withPrefix(key)).Result()
+}
+
+// RPush insert all the specified values at the tail of the list stored at key
+func (p *PrefixedRedisClient) RPush(key string, values ...interface{}) (int64, error) {
+	return p.Client.RPush(p.withPrefix(key), values...).Result()
+}
+
+// LRange Returns the specified elements of the list stored at key
+func (p *PrefixedRedisClient) LRange(key string, start, stop int64) ([]string, error) {
+	return p.Client.LRange(p.withPrefix(key), start, stop).Multi()
+}
+
+// LTrim Trim an existing list so that it will contain only the specified range of elements specified
+func (p *PrefixedRedisClient) LTrim(key string, start, stop int64) error {
+	return p.Client.LTrim(p.withPrefix(key), start, stop).Err()
+}
+
+// LLen Returns the length of the list stored at key
+func (p *PrefixedRedisClient) LLen(key string) (int64, error) {
+	return p.Client.LLen(p.withPrefix(key)).Result()
+}
+
+// Expire set expiration time for particular key
+func (p *PrefixedRedisClient) Expire(key string, value time.Duration) bool {
+	return p.Client.Expire(p.withPrefix(key), value).Bool()
+}
+
+// TTL for particular key
+func (p *PrefixedRedisClient) TTL(key string) time.Duration {
+	return p.Client.TTL(p.withPrefix(key)).Duration()
+}
+
+// MGet fetchs multiple results
+func (p *PrefixedRedisClient) MGet(keys []string) ([]interface{}, error) {
+	keysWithPrefix := make([]string, 0)
+	for _, key := range keys {
+		keysWithPrefix = append(keysWithPrefix, p.withPrefix(key))
+	}
+	return p.Client.MGet(keysWithPrefix).MultiInterface()
+}
+
+// SCard implements SCard wrapper for redis
+func (p *PrefixedRedisClient) SCard(key string) (int64, error) {
+	return p.Client.SCard(p.withPrefix(key)).Result()
+}
+
+// Eval implements Eval wrapper for redis
+func (p *PrefixedRedisClient) Eval(script string, keys []string, args ...interface{}) error {
+	return p.Client.Eval(script, keys, args...).Err()
+}
+
+// NewPrefixedRedisClient returns a new Prefixed Redis Client
+func NewPrefixedRedisClient(redisClient Client, prefix string) (*PrefixedRedisClient, error) {
+	return &PrefixedRedisClient{
+		Client: redisClient,
+		Prefix: prefix,
+	}, nil
+}

vendor/github.com/splitio/go-toolkit/v3/redis/types.go

@@ -0,0 +1,8 @@
+package redis
+
+import (
+	wredis "github.com/go-redis/redis/v8"
+)
+
+// UniversalOptions type used for redis package
+type UniversalOptions = wredis.UniversalOptions

vendor/github.com/splitio/go-toolkit/v3/redis/wrapper.go

@@ -0,0 +1,293 @@
+package redis
+
+import (
+	"context"
+	"time"
+
+	"github.com/go-redis/redis/v8"
+)
+
+// ===== Command output / return value types
+
+// Result generic interface
+type Result interface {
+	Int() int64
+	String() string
+	Bool() bool
+	Duration() time.Duration
+	Result() (int64, error)
+	ResultString() (string, error)
+	Multi() ([]string, error)
+	MultiInterface() ([]interface{}, error)
+	Err() error
+}
+
+// ResultImpl generic interface
+type ResultImpl struct {
+	value          int64
+	valueString    string
+	valueBool      bool
+	valueDuration  time.Duration
+	err            error
+	multi          []string
+	multiInterface []interface{}
+}
+
+// Int implementation
+func (r *ResultImpl) Int() int64 {
+	return r.value
+}
+
+// String implementation
+func (r *ResultImpl) String() string {
+	return r.valueString
+}
+
+// Bool implementation
+func (r *ResultImpl) Bool() bool {
+	return r.valueBool
+}
+
+// Duration implementation
+func (r *ResultImpl) Duration() time.Duration {
+	return r.valueDuration
+}
+
+// Err implementation
+func (r *ResultImpl) Err() error {
+	return r.err
+}
+
+// Result implementation
+func (r *ResultImpl) Result() (int64, error) {
+	return r.value, r.err
+}
+
+// ResultString implementation
+func (r *ResultImpl) ResultString() (string, error) {
+	return r.valueString, r.err
+}
+
+// Multi implementation
+func (r *ResultImpl) Multi() ([]string, error) {
+	return r.multi, r.err
+}
+
+// MultiInterface implementation
+func (r *ResultImpl) MultiInterface() ([]interface{}, error) {
+	return r.multiInterface, r.err
+}
+
+// ====== Client
+
+// Client interface which specifies the currently used subset of redis operations
+type Client interface {
+	Del(keys ...string) Result
+	Exists(keys ...string) Result
+	Get(key string) Result
+	Set(key string, value interface{}, expiration time.Duration) Result
+	Ping() Result
+	Keys(pattern string) Result
+	SMembers(key string) Result
+	SIsMember(key string, member interface{}) Result
+	SAdd(key string, members ...interface{}) Result
+	SRem(key string, members ...interface{}) Result
+	Incr(key string) Result
+	Decr(key string) Result
+	RPush(key string, values ...interface{}) Result
+	LRange(key string, start, stop int64) Result
+	LTrim(key string, start, stop int64) Result
+	LLen(key string) Result
+	Expire(key string, value time.Duration) Result
+	TTL(key string) Result
+	MGet(keys []string) Result
+	SCard(key string) Result
+	Eval(script string, keys []string, args ...interface{}) Result
+}
+
+// ClientImpl wrapps redis client
+type ClientImpl struct {
+	wrapped redis.UniversalClient
+}
+
+func (c *ClientImpl) wrapResult(result interface{}) Result {
+	if result == nil {
+		return nil
+	}
+	switch v := result.(type) {
+	case *redis.StatusCmd:
+		return &ResultImpl{
+			valueString: v.Val(),
+			err:         v.Err(),
+		}
+	case *redis.IntCmd:
+		return &ResultImpl{
+			value: v.Val(),
+			err:   v.Err(),
+		}
+	case *redis.StringCmd:
+		return &ResultImpl{
+			valueString: v.Val(),
+			err:         v.Err(),
+		}
+	case *redis.StringSliceCmd:
+		return &ResultImpl{
+			err:   v.Err(),
+			multi: v.Val(),
+		}
+	case *redis.BoolCmd:
+		return &ResultImpl{
+			valueBool: v.Val(),
+			err:       v.Err(),
+		}
+	case *redis.DurationCmd:
+		return &ResultImpl{
+			valueDuration: v.Val(),
+			err:           v.Err(),
+		}
+	case *redis.SliceCmd:
+		return &ResultImpl{
+			err:            v.Err(),
+			multiInterface: v.Val(),
+		}
+	case *redis.Cmd:
+		return &ResultImpl{
+			err: v.Err(),
+		}
+	default:
+		return nil
+	}
+}
+
+// Del implements Del wrapper for redis
+func (c *ClientImpl) Del(keys ...string) Result {
+	res := c.wrapped.Del(context.TODO(), keys...)
+	return c.wrapResult(res)
+}
+
+// Exists implements Exists wrapper for redis
+func (c *ClientImpl) Exists(keys ...string) Result {
+	res := c.wrapped.Exists(context.TODO(), keys...)
+	return c.wrapResult(res)
+}
+
+// Get implements Get wrapper for redis
+func (c *ClientImpl) Get(key string) Result {
+	res := c.wrapped.Get(context.TODO(), key)
+	return c.wrapResult(res)
+}
+
+// Set implements Set wrapper for redis
+func (c *ClientImpl) Set(key string, value interface{}, expiration time.Duration) Result {
+	res := c.wrapped.Set(context.TODO(), key, value, expiration)
+	return c.wrapResult(res)
+}
+
+// Ping implements Ping wrapper for redis
+func (c *ClientImpl) Ping() Result {
+	res := c.wrapped.Ping(context.TODO())
+	return c.wrapResult(res)
+}
+
+// Keys implements Keys wrapper for redis
+func (c *ClientImpl) Keys(pattern string) Result {
+	res := c.wrapped.Keys(context.TODO(), pattern)
+	return c.wrapResult(res)
+}
+
+// SMembers implements SMembers wrapper for redis
+func (c *ClientImpl) SMembers(key string) Result {
+	res := c.wrapped.SMembers(context.TODO(), key)
+	return c.wrapResult(res)
+}
+
+// SIsMember implements SIsMember wrapper for redis
+func (c *ClientImpl) SIsMember(key string, member interface{}) Result {
+	res := c.wrapped.SIsMember(context.TODO(), key, member)
+	return c.wrapResult(res)
+}
+
+// SAdd implements SAdd wrapper for redis
+func (c *ClientImpl) SAdd(key string, members ...interface{}) Result {
+	res := c.wrapped.SAdd(context.TODO(), key, members...)
+	return c.wrapResult(res)
+}
+
+// SRem implements SRem wrapper for redis
+func (c *ClientImpl) SRem(key string, members ...interface{}) Result {
+	res := c.wrapped.SRem(context.TODO(), key, members...)
+	return c.wrapResult(res)
+}
+
+// Incr implements Incr wrapper for redis
+func (c *ClientImpl) Incr(key string) Result {
+	res := c.wrapped.Incr(context.TODO(), key)
+	return c.wrapResult(res)
+}
+
+// Decr implements Decr wrapper for redis
+func (c *ClientImpl) Decr(key string) Result {
+	res := c.wrapped.Decr(context.TODO(), key)
+	return c.wrapResult(res)
+}
+
+// RPush implements RPush wrapper for redis
+func (c *ClientImpl) RPush(key string, values ...interface{}) Result {
+	res := c.wrapped.RPush(context.TODO(), key, values...)
+	return c.wrapResult(res)
+}
+
+// LRange implements LRange wrapper for redis
+func (c *ClientImpl) LRange(key string, start, stop int64) Result {
+	res := c.wrapped.LRange(context.TODO(), key, start, stop)
+	return c.wrapResult(res)
+}
+
+// LTrim implements LTrim wrapper for redis
+func (c *ClientImpl) LTrim(key string, start, stop int64) Result {
+	res := c.wrapped.LTrim(context.TODO(), key, start, stop)
+	return c.wrapResult(res)
+}
+
+// LLen implements LLen wrapper for redis
+func (c *ClientImpl) LLen(key string) Result {
+	res := c.wrapped.LLen(context.TODO(), key)
+	return c.wrapResult(res)
+}
+
+// Expire implements Expire wrapper for redis
+func (c *ClientImpl) Expire(key string, value time.Duration) Result {
+	res := c.wrapped.Expire(context.TODO(), key, value)
+	return c.wrapResult(res)
+}
+
+// TTL implements TTL wrapper for redis
+func (c *ClientImpl) TTL(key string) Result {
+	res := c.wrapped.TTL(context.TODO(), key)
+	return c.wrapResult(res)
+}
+
+// MGet implements MGet wrapper for redis
+func (c *ClientImpl) MGet(keys []string) Result {
+	res := c.wrapped.MGet(context.TODO(), keys...)
+	return c.wrapResult(res)
+}
+
+// SCard implements SCard wrapper for redis
+func (c *ClientImpl) SCard(key string) Result {
+	res := c.wrapped.SCard(context.TODO(), key)
+	return c.wrapResult(res)
+}
+
+// Eval implements Eval wrapper for redis
+func (c *ClientImpl) Eval(script string, keys []string, args ...interface{}) Result {
+	res := c.wrapped.Eval(context.TODO(), script, keys, args...)
+	return c.wrapResult(res)
+}
+
+// NewClient returns new client implementation
+func NewClient(options *UniversalOptions) (Client, error) {
+	return &ClientImpl{
+		wrapped: redis.NewUniversalClient(options),
+	}, nil
+}

vendor/github.com/splitio/go-toolkit/v3/sse/sse.go

@@ -0,0 +1,214 @@
+package sse
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/splitio/go-toolkit/v3/logging"
+)
+
+const (
+	// OK It could connect streaming
+	OK = iota
+	// ErrorOnClientCreation Could not create client
+	ErrorOnClientCreation
+	// ErrorRequestPerformed Could not perform request
+	ErrorRequestPerformed
+	// ErrorConnectToStreaming Could not connect to streaming
+	ErrorConnectToStreaming
+	// ErrorReadingStream Error in streaming
+	ErrorReadingStream
+	// ErrorKeepAlive timedout
+	ErrorKeepAlive
+	// ErrorInternal Internal error for streaming
+	ErrorInternal
+	// ErrorUnexpected unexpected error occures
+	ErrorUnexpected
+)
+
+var sseDelimiter [2]byte = [...]byte{':', ' '}
+var sseData [4]byte = [...]byte{'d', 'a', 't', 'a'}
+var sseKeepAlive [10]byte = [...]byte{':', 'k', 'e', 'e', 'p', 'a', 'l', 'i', 'v', 'e'}
+
+// SSEClient struct
+type SSEClient struct {
+	url      string
+	client   http.Client
+	status   chan int
+	shutdown chan struct{}
+	timeout  int
+	logger   logging.LoggerInterface
+}
+
+// NewSSEClient creates new SSEClient
+func NewSSEClient(url string, status chan int, timeout int, logger logging.LoggerInterface) (*SSEClient, error) {
+	if cap(status) < 1 {
+		return nil, errors.New("Status channel should have length")
+	}
+	if timeout < 1 {
+		return nil, errors.New("Timeout should be higher than 0")
+	}
+	return &SSEClient{
+		url:      url,
+		client:   http.Client{},
+		status:   status,
+		shutdown: make(chan struct{}, 1),
+		timeout:  timeout,
+		logger:   logger,
+	}, nil
+}
+
+// Shutdown stops SSE
+func (l *SSEClient) Shutdown() {
+	select {
+	case l.shutdown <- struct{}{}:
+	default:
+		l.logger.Error("Awaited unexpected event")
+	}
+}
+
+func parseData(raw []byte) (map[string]interface{}, error) {
+	data := make(map[string]interface{})
+	err := json.Unmarshal(raw, &data)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing json: %w", err)
+	}
+	return data, nil
+}
+
+func (l *SSEClient) readEvent(reader *bufio.Reader) (map[string]interface{}, error) {
+	line, err := reader.ReadBytes('\n')
+	if err != nil {
+		return nil, err
+	}
+
+	if len(line) < 2 {
+		return nil, nil
+	}
+
+	splitted := bytes.Split(line, sseDelimiter[:])
+
+	if bytes.Compare(splitted[0], sseData[:]) != 0 {
+		return nil, nil
+	}
+
+	raw := bytes.TrimSpace(splitted[1])
+	l.logger.Debug("LINE:", string(line))
+	data, err := parseData(raw)
+	if err != nil {
+		l.logger.Error("Error parsing event: ", err)
+		return nil, nil
+	}
+
+	return data, nil
+}
+
+func parseHTTPError(resp *http.Response) int {
+	if resp.StatusCode >= http.StatusInternalServerError {
+		return ErrorInternal
+	}
+	return ErrorConnectToStreaming
+}
+
+// Do starts streaming
+func (l *SSEClient) Do(params map[string]string, callback func(e map[string]interface{})) {
+	select {
+	case <-l.shutdown:
+		// Skipping previous shutdown
+	default:
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	shouldRun := atomic.Value{}
+	shouldRun.Store(false)
+	activeGoroutines := sync.WaitGroup{}
+	defer func() {
+		l.logger.Info("SSE streaming exiting")
+		cancel()
+		shouldRun.Store(false)
+		activeGoroutines.Wait()
+	}()
+
+	req, err := http.NewRequest("GET", l.url, nil)
+	if err != nil {
+		l.logger.Error(err)
+		l.status <- ErrorOnClientCreation
+		return
+	}
+	req = req.WithContext(ctx)
+	query := req.URL.Query()
+
+	for key, value := range params {
+		query.Add(key, value)
+	}
+	req.URL.RawQuery = query.Encode()
+	req.Header.Set("Accept", "text/event-stream")
+
+	resp, err := l.client.Do(req)
+	if err != nil {
+		l.logger.Error(err)
+		l.status <- ErrorRequestPerformed
+		return
+	}
+
+	if resp.StatusCode != 200 {
+		l.status <- parseHTTPError(resp)
+		return
+	}
+	defer resp.Body.Close()
+
+	l.status <- OK
+	reader := bufio.NewReader(resp.Body)
+
+	eventChannel := make(chan map[string]interface{}, 1000)
+	shouldRun.Store(true)
+	go func() {
+		for shouldRun.Load().(bool) {
+			event, err := l.readEvent(reader)
+			if err != nil {
+				l.logger.Error(err)
+				close(eventChannel)
+				return
+			}
+			eventChannel <- event
+		}
+	}()
+
+	// Create timeout timer in case SSE dont receive notifications or keepalive messages
+	idleDuration := time.Duration(l.timeout) * time.Second
+	keepAliveTimer := time.NewTimer(idleDuration)
+	defer keepAliveTimer.Stop()
+
+	for {
+		//  Resetting timer
+		keepAliveTimer.Reset(idleDuration)
+
+		select {
+		case <-l.shutdown:
+			l.logger.Info("Shutting down listener")
+			return
+		case event, ok := <-eventChannel:
+			if !ok {
+				l.status <- ErrorReadingStream
+				return
+			}
+			if event != nil {
+				activeGoroutines.Add(1)
+				go func() {
+					defer activeGoroutines.Done()
+					callback(event)
+				}()
+			}
+		case <-keepAliveTimer.C: // Timedout
+			l.status <- ErrorKeepAlive
+			return
+		}
+	}
+}

vendor/github.com/splitio/go-toolkit/v3/workerpool/workerpool.go

@@ -0,0 +1,166 @@
+package workerpool
+
+import (
+	"fmt"
+	"github.com/splitio/go-toolkit/v3/logging"
+	"sync"
+	"time"
+)
+
+const (
+	workerSignalStop = iota
+)
+
+// WorkerAdmin struct handles multiple worker execution, popping jobs from a single queue
+type WorkerAdmin struct {
+	queue        chan interface{}
+	signalsMutex sync.RWMutex
+	signals      map[string]chan int
+	logger       logging.LoggerInterface
+	wg           sync.WaitGroup
+}
+
+// Worker interface should be implemented by concrete workers that will perform the actual job
+type Worker interface {
+	// Name should return a unique identifier for a particular worker
+	Name() string
+	// DoWork should receive a message, and perform the actual work, only an error should be returned
+	DoWork(message interface{}) error
+	// OnError will be called if DoWork returns an error != nil
+	OnError(e error)
+	// Cleanup will be called when the worker is shutting down
+	Cleanup() error
+	// FailureTime should return the amount of time the worker should wait after resuming work if an error occurs
+	FailureTime() int64
+}
+
+func (a *WorkerAdmin) workerWrapper(w Worker) {
+	a.signalsMutex.Lock()
+	a.signals[w.Name()] = make(chan int, 10)
+	a.signalsMutex.Unlock()
+	defer a.wg.Done()
+	defer func() {
+		if r := recover(); r != nil {
+			a.logger.Error(fmt.Sprintf(
+				"Worker %s is panicking with the following error \"%s\" and will be shutted down.",
+				w.Name(),
+				r,
+			))
+		}
+		if a.signals != nil { // This should ALWAYS be the case, but just in case... we don't want to panic here.
+			a.signalsMutex.Lock()
+			delete(a.signals, w.Name())
+			a.signalsMutex.Unlock()
+		}
+	}()
+	defer w.Cleanup()
+	for {
+		a.signalsMutex.RLock()
+		signal := a.signals[w.Name()]
+		a.signalsMutex.RUnlock()
+		select {
+		case msg := <-signal:
+			switch msg {
+			case workerSignalStop:
+				return
+			}
+		case msg := <-a.queue:
+			if err := w.DoWork(msg); err != nil {
+				w.OnError(err)
+				time.Sleep(time.Duration(w.FailureTime()) * time.Millisecond)
+			}
+		}
+	}
+}
+
+// AddWorker registers a new worker in the admin
+func (a *WorkerAdmin) AddWorker(w Worker) {
+	if w == nil {
+		a.logger.Error("AddWorker called with nil")
+		return
+	}
+	a.wg.Add(1)
+	go a.workerWrapper(w)
+}
+
+// QueueMessage adds a new message that will be popped by a worker and processed
+func (a *WorkerAdmin) QueueMessage(m interface{}) bool {
+	if m == nil {
+		a.logger.Warning("Nil message not added to queue")
+		return false
+	}
+	select {
+	case a.queue <- m:
+		return true
+	default:
+		return false
+	}
+}
+
+// StopWorker ends the worker's event loop, preventing it from picking further jobs
+func (a *WorkerAdmin) StopWorker(name string) error {
+	a.signalsMutex.RLock()
+	c, ok := a.signals[name]
+	a.signalsMutex.RUnlock()
+	if !ok {
+		return fmt.Errorf("Worker %s doesn't exist, hence it cannot be stopped", name)
+	}
+	select {
+	case c <- workerSignalStop:
+	default:
+		return fmt.Errorf("Couldn't send stop signal to worker %s", name)
+	}
+	return nil
+}
+
+// StopAll ends all worker's event loops
+func (a *WorkerAdmin) StopAll(blocking bool) error {
+	failed := make([]string, 0)
+	workerNames := make([]string, 0)
+
+	// Get worker names safely
+	a.signalsMutex.RLock()
+	for workerName := range a.signals {
+		workerNames = append(workerNames, workerName)
+	}
+	a.signalsMutex.RUnlock()
+
+	for _, workerName := range workerNames {
+		err := a.StopWorker(workerName)
+		if err != nil {
+			a.logger.Error(err)
+			failed = append(failed, workerName)
+		}
+	}
+	if len(failed) > 0 {
+		return fmt.Errorf("Workers %v failed to shutdown", failed)
+	}
+
+	if blocking {
+		a.wg.Wait()
+	}
+
+	return nil
+}
+
+// QueueSize returns the current queue size
+func (a *WorkerAdmin) QueueSize() int {
+	return len(a.queue)
+}
+
+// IsWorkerRunning returns true if the worker exists and is currently running
+func (a *WorkerAdmin) IsWorkerRunning(name string) bool {
+	a.signalsMutex.RLock()
+	_, ok := a.signals[name]
+	a.signalsMutex.RUnlock()
+	return ok // We consider a worker to be running if it exists in the list of valid signal channels
+}
+
+// NewWorkerAdmin instantiates a new WorkerAdmin and returns a pointer to it.
+func NewWorkerAdmin(queueSize int, logger logging.LoggerInterface) *WorkerAdmin {
+	return &WorkerAdmin{
+		signals: make(map[string]chan int, 0),
+		logger:  logger,
+		queue:   make(chan interface{}, queueSize),
+	}
+}