fnv

collections/generics/concurrent_map_test.go

@@ -5,7 +5,9 @@ import (
 	"runtime"
 	"testing"
 
+	"github.com/charlienet/go-mixed/bytesconv"
 	"github.com/charlienet/go-mixed/collections/generics"
+	"github.com/charlienet/go-mixed/hash"
 )
 
 func TestConcurrentMap(t *testing.T) {
@@ -81,3 +83,86 @@ func BenchmarkRWLockMap(b *testing.B) {
 		}
 	})
 }
+
+func BenchmarkGetIndex(b *testing.B) {
+
+	b.Run("字符串-Sprintf", func(b *testing.B) {
+		v := "abc"
+		for i := 0; i < b.N; i++ {
+			bytes := []byte(fmt.Sprintf("%v", v))
+			hash.XXHashUint64(bytes)
+		}
+	})
+
+	b.Run("字符串", func(b *testing.B) {
+		v := "abc"
+		for i := 0; i < b.N; i++ {
+			getTag(v)
+		}
+	})
+
+	b.Run("数字", func(b *testing.B) {
+		v := 124
+		for i := 0; i < b.N; i++ {
+			getTag(v)
+		}
+	})
+}
+
+func getTag[T comparable](v T) uint64 {
+	var vv any = v
+
+	switch vv.(type) {
+	case string:
+		return getStringIndex([]byte(vv.(string)))
+	case int8:
+		return uint64(vv.(int8))
+	case uint8:
+		return uint64(vv.(uint8))
+	case int:
+		return uint64(vv.(int))
+	case int32:
+		return uint64(vv.(int32))
+	case uint32:
+		return uint64(vv.(uint32))
+	case int64:
+		return uint64(vv.(int64))
+	case uint64:
+		return vv.(uint64)
+	default:
+		return getStringIndex([]byte(fmt.Sprintf("%v", v)))
+	}
+}
+
+func getStringIndex(v []byte) uint64 {
+	if len(v) > 4 {
+		v = v[:4]
+	}
+
+	// return hash.XXHashUint64(v)
+	i, _ := bytesconv.BigEndian.BytesToUInt64(v)
+	return i
+}
+
+func TestFnv64(t *testing.T) {
+	t.Log(fnv64("a"))
+	t.Log(fnv64("b"))
+	t.Log(fnv64("c"))
+	t.Log(fnv64("d"))
+	t.Log(fnv64("e"))
+}
+
+const (
+	prime32 = uint64(16777619)
+)
+
+func fnv64(k string) uint64 {
+	var hash = uint64(2166136261)
+	l := len(k)
+	for i := 0; i < l; i++ {
+		hash *= prime32
+		hash ^= uint64(k[i])
+	}
+
+	return hash
+}