From 2dba5dbf86866a327b1dec3a8ee3d83a68daeef5 Mon Sep 17 00:00:00 2001
From: Agniva De Sarker <agnivade@yahoo.co.in>
Date: Thu, 9 Jan 2020 21:14:01 +0530
Subject: [PATCH] MM-21368: Optimize MapStringsToQueryParams (#13601)
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- Use strings.Builder which minimizes allocations.
- Avoid fmt.Sprintf which is slower than simple string concat.

Results:

name                                      old time/op    new time/op    delta
MapStringsToQueryParams/one_item-8           512ns ± 2%     377ns ± 1%  -26.27%  (p=0.000 n=10+9)
MapStringsToQueryParams/multiple_items-8     858ns ± 5%     748ns ± 2%  -12.82%  (p=0.000 n=10+9)

name                                      old alloc/op   new alloc/op   delta
MapStringsToQueryParams/one_item-8            456B ± 0%      384B ± 0%  -15.79%  (p=0.000 n=10+9)
MapStringsToQueryParams/multiple_items-8      608B ± 0%      592B ± 0%   -2.63%  (p=0.000 n=10+10)

name                                      old allocs/op  new allocs/op  delta
MapStringsToQueryParams/one_item-8            8.00 ± 0%      6.00 ± 0%  -25.00%  (p=0.000 n=10+10)
MapStringsToQueryParams/multiple_items-8      12.0 ± 0%      12.0 ± 0%     ~     (all equal)
---
 store/sqlstore/utils.go      |  6 ++----
 store/sqlstore/utils_test.go | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/store/sqlstore/utils.go b/store/sqlstore/utils.go
index 4018a17a65..1ca8f1fe70 100644
--- a/store/sqlstore/utils.go
+++ b/store/sqlstore/utils.go
@@ -4,9 +4,7 @@
 package sqlstore
 
 import (
-	"bytes"
 	"database/sql"
-	"fmt"
 	"strconv"
 	"strings"
 
@@ -32,7 +30,7 @@ func sanitizeSearchTerm(term string, escapeChar string) string {
 // Converts a list of strings into a list of query parameters and a named parameter map that can
 // be used as part of a SQL query.
 func MapStringsToQueryParams(list []string, paramPrefix string) (string, map[string]interface{}) {
-	keys := bytes.Buffer{}
+	var keys strings.Builder
 	params := make(map[string]interface{}, len(list))
 	for i, entry := range list {
 		if keys.Len() > 0 {
@@ -44,7 +42,7 @@ func MapStringsToQueryParams(list []string, paramPrefix string) (string, map[str
 		params[key] = entry
 	}
 
-	return fmt.Sprintf("(%v)", keys.String()), params
+	return "(" + keys.String() + ")", params
 }
 
 // finalizeTransaction ensures a transaction is closed after use, rolling back if not already committed.
diff --git a/store/sqlstore/utils_test.go b/store/sqlstore/utils_test.go
index e7c6bdce2d..7db47c61ac 100644
--- a/store/sqlstore/utils_test.go
+++ b/store/sqlstore/utils_test.go
@@ -33,6 +33,24 @@ func TestMapStringsToQueryParams(t *testing.T) {
 	})
 }
 
+var keys string
+var params map[string]interface{}
+
+func BenchmarkMapStringsToQueryParams(b *testing.B) {
+	b.Run("one item", func(b *testing.B) {
+		input := []string{"apple"}
+		for i := 0; i < b.N; i++ {
+			keys, params = MapStringsToQueryParams(input, "Fruit")
+		}
+	})
+	b.Run("multiple items", func(b *testing.B) {
+		input := []string{"carrot", "tomato", "potato"}
+		for i := 0; i < b.N; i++ {
+			keys, params = MapStringsToQueryParams(input, "Vegetable")
+		}
+	})
+}
+
 func TestSanitizeSearchTerm(t *testing.T) {
 	term := "test"
 	result := sanitizeSearchTerm(term, "\\")