From e7336cc3bfcf60eb775c60509d521e92a5a3b6fe Mon Sep 17 00:00:00 2001
From: Mohammed Al Sahaf <msaa1990@gmail.com>
Date: Thu, 21 Mar 2024 21:15:18 +0300
Subject: [PATCH] replacer: use RWMutex to protect static provider (#6184)

---
 replacer.go      | 17 ++++++++++++++---
 replacer_test.go |  4 ++++
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/replacer.go b/replacer.go
index 046be867a..2ad5b8bcb 100644
--- a/replacer.go
+++ b/replacer.go
@@ -22,13 +22,15 @@ import (
 	"runtime"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
 // NewReplacer returns a new Replacer.
 func NewReplacer() *Replacer {
 	rep := &Replacer{
-		static: make(map[string]any),
+		static:   make(map[string]any),
+		mapMutex: &sync.RWMutex{},
 	}
 	rep.providers = []ReplacerFunc{
 		globalDefaultReplacements,
@@ -41,7 +43,8 @@ func NewReplacer() *Replacer {
 // without the global default replacements.
 func NewEmptyReplacer() *Replacer {
 	rep := &Replacer{
-		static: make(map[string]any),
+		static:   make(map[string]any),
+		mapMutex: &sync.RWMutex{},
 	}
 	rep.providers = []ReplacerFunc{
 		rep.fromStatic,
@@ -54,7 +57,9 @@ func NewEmptyReplacer() *Replacer {
 // use NewReplacer to make one.
 type Replacer struct {
 	providers []ReplacerFunc
-	static    map[string]any
+
+	static   map[string]any
+	mapMutex *sync.RWMutex
 }
 
 // Map adds mapFunc to the list of value providers.
@@ -65,7 +70,9 @@ func (r *Replacer) Map(mapFunc ReplacerFunc) {
 
 // Set sets a custom variable to a static value.
 func (r *Replacer) Set(variable string, value any) {
+	r.mapMutex.Lock()
 	r.static[variable] = value
+	r.mapMutex.Unlock()
 }
 
 // Get gets a value from the replacer. It returns
@@ -89,11 +96,15 @@ func (r *Replacer) GetString(variable string) (string, bool) {
 // Delete removes a variable with a static value
 // that was created using Set.
 func (r *Replacer) Delete(variable string) {
+	r.mapMutex.Lock()
 	delete(r.static, variable)
+	r.mapMutex.Unlock()
 }
 
 // fromStatic provides values from r.static.
 func (r *Replacer) fromStatic(key string) (any, bool) {
+	r.mapMutex.RLock()
+	defer r.mapMutex.RUnlock()
 	val, ok := r.static[key]
 	return val, ok
 }
diff --git a/replacer_test.go b/replacer_test.go
index c88683947..d18ec8eea 100644
--- a/replacer_test.go
+++ b/replacer_test.go
@@ -19,6 +19,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"sync"
 	"testing"
 )
 
@@ -238,6 +239,7 @@ func TestReplacerSet(t *testing.T) {
 
 func TestReplacerReplaceKnown(t *testing.T) {
 	rep := Replacer{
+		mapMutex: &sync.RWMutex{},
 		providers: []ReplacerFunc{
 			// split our possible vars to two functions (to test if both functions are called)
 			func(key string) (val any, ok bool) {
@@ -310,6 +312,7 @@ func TestReplacerReplaceKnown(t *testing.T) {
 
 func TestReplacerDelete(t *testing.T) {
 	rep := Replacer{
+		mapMutex: &sync.RWMutex{},
 		static: map[string]any{
 			"key1": "val1",
 			"key2": "val2",
@@ -463,5 +466,6 @@ func testReplacer() Replacer {
 	return Replacer{
 		providers: make([]ReplacerFunc, 0),
 		static:    make(map[string]any),
+		mapMutex:  &sync.RWMutex{},
 	}
 }