Add sync.map and optimise

Author: soujanyanmbri

Diff for: internal/corazawaf/rule.go

@@ -5,7 +5,9 @@ package corazawaf
 
 import (
 	"fmt"
+	"hash/fnv"
 	"regexp"
+	"strconv"
 	"strings"
 	"sync"
 	"unsafe"
@@ -585,23 +587,14 @@ func (r *Rule) AddVariableNegation(v variables.RuleVariable, key string) error {
 	return nil
 }
 
-var transformationIDToName = []string{""}
-var transformationNameToID = map[string]int{"": 0}
-var transformationIDsLock = sync.Mutex{}
+var transformationNameToID sync.Map
 
 func transformationID(currentID int, transformationName string) int {
-	transformationIDsLock.Lock()
-	defer transformationIDsLock.Unlock()
-
-	currName := transformationIDToName[currentID]
-	nextName := fmt.Sprintf("%s+%s", currName, transformationName)
-	if id, ok := transformationNameToID[nextName]; ok {
-		return id
-	}
-
-	id := len(transformationIDToName)
-	transformationIDToName = append(transformationIDToName, nextName)
-	transformationNameToID[nextName] = id
+	nextName := strconv.Itoa(currentID) + "+" + transformationName
+	hasher := fnv.New64a()
+	hasher.Write([]byte(nextName))
+	id := int(hasher.Sum64())
+	transformationNameToID.LoadOrStore(id, nextName)
 	return id
 }
 

Diff for: internal/corazawaf/rule_test.go

@@ -384,6 +384,23 @@ func TestAddTransformation(t *testing.T) {
 	}
 }
 
+func BenchmarkAddTransformationUnique(b *testing.B) {
+	transformation := func(input string) (string, bool, error) {
+		return "Test", true, nil
+	}
+	b.ResetTimer()
+	b.RunParallel(func(p *testing.PB) {
+		rule := NewRule()
+		for p.Next() {
+			transformationName := "transformation" + b.Name()
+			err := rule.AddTransformation(transformationName, transformation)
+			if err != nil {
+				b.Fatalf("Failed to add a transformation: %s", err.Error())
+			}
+		}
+	})
+}
+
 func TestAddTransformationEmpty(t *testing.T) {
 	rule := NewRule()
 	transformationName := ""