From 68ceacfde1ee53610403eec3868c88f5c9db29be Mon Sep 17 00:00:00 2001
From: yunlongn <yunlongn@outlook.com>
Date: Fri, 29 Jul 2022 22:10:34 +0800
Subject: [PATCH] [type:feat] cache caller.

---
 logfactory/caller.go  | 49 +++++++++++++++++++++++++++++++++++++++++++
 logfactory/logging.go |  2 +-
 2 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 logfactory/caller.go

diff --git a/logfactory/caller.go b/logfactory/caller.go
new file mode 100644
index 0000000..6125ef2
--- /dev/null
+++ b/logfactory/caller.go
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2022, AcmeStack
+ * All rights reserved.
+ *
+ * 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.
+ */
+
+package logfactory
+
+import (
+	"runtime"
+	"sync"
+)
+
+// frameMap 用于缓存调用点，基准测试表明使用缓存大约有 50% 的性能提升。
+var frameMap sync.Map
+
+// Caller 获取调用点的文件及行号信息，fast 为 true 时使用缓存进行加速。
+func Caller(skip int, fast bool) (pc uintptr, file string, line int, ok bool) {
+
+	if !fast {
+		pc, file, line, ok = runtime.Caller(skip + 1)
+		return
+	}
+
+	rpc := make([]uintptr, 1)
+	n := runtime.Callers(skip+2, rpc[:])
+	if n < 1 {
+		return
+	}
+	pc2 := rpc[0]
+	if v, ok := frameMap.Load(pc2); ok {
+		e := v.(*runtime.Frame)
+		return pc2, e.File, e.Line, true
+	}
+	frame, _ := runtime.CallersFrames(rpc).Next()
+	frameMap.Store(pc2, &frame)
+	return pc2, frame.File, frame.Line, true
+}
diff --git a/logfactory/logging.go b/logfactory/logging.go
index 79d2cdb..019d30d 100644
--- a/logfactory/logging.go
+++ b/logfactory/logging.go
@@ -236,7 +236,7 @@ func NewLogging(opts ...LoggingOpt) Logging {
 
 func (l *logging) getCaller(depth int) string {
 	if l.fileFlag != CallerNone {
-		pc, file, line, ok := runtime.Caller(depth + 3)
+		pc, file, line, ok := Caller(depth+3, true)
 		if !ok {
 			return "???"
 		}