From 7721e540e2c016c95611341ec97ae04a84c78587 Mon Sep 17 00:00:00 2001
From: Changxin Miao <miaochangxin@step.ai>
Date: Tue, 26 Nov 2024 21:33:00 +0800
Subject: [PATCH] Output method name in log (#5322)

Signed-off-by: Changxin Miao <miaochangxin@step.ai>
---
 pkg/utils/logger.go      | 31 ++++++++++++++++++++++++++++++-
 pkg/utils/logger_test.go | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/pkg/utils/logger.go b/pkg/utils/logger.go
index 5d6a5cd50110..2a686c4f7142 100644
--- a/pkg/utils/logger.go
+++ b/pkg/utils/logger.go
@@ -61,13 +61,14 @@ func (l *logHandle) Format(e *logrus.Entry) ([]byte, error) {
 	}
 	const timeFormat = "2006/01/02 15:04:05.000000"
 	timestamp := e.Time.Format(timeFormat)
-	str := fmt.Sprintf("%s%v %s[%d] <%v>: %v [%s:%d]",
+	str := fmt.Sprintf("%s%v %s[%d] <%v>: %v [%s@%s:%d]",
 		l.logid,
 		timestamp,
 		l.name,
 		os.Getpid(),
 		lvlStr,
 		strings.TrimRight(e.Message, "\n"),
+		methodName(e.Caller.Function),
 		path.Base(e.Caller.File),
 		e.Caller.Line)
 
@@ -80,6 +81,34 @@ func (l *logHandle) Format(e *logrus.Entry) ([]byte, error) {
 	return []byte(str), nil
 }
 
+// Returns a human-readable method name, removing internal markers added by Go
+func methodName(fullFuncName string) string {
+	firstSlash := strings.Index(fullFuncName, "/")
+	if firstSlash != -1 && firstSlash < len(fullFuncName)-1 {
+		fullFuncName = fullFuncName[firstSlash+1:]
+	}
+	lastDot := strings.LastIndex(fullFuncName, ".")
+	if lastDot == -1 || lastDot == len(fullFuncName)-1 {
+		return fullFuncName
+	}
+	method := fullFuncName[lastDot+1:]
+	// avoid func1
+	if strings.HasPrefix(method, "func") && method[4] >= '0' && method[4] <= '9' {
+		candidate := methodName(fullFuncName[:lastDot])
+		if candidate != "" {
+			method = candidate
+		}
+	}
+	// aoid init.3
+	if len(method) == 1 && method[0] >= '0' && method[0] <= '9' {
+		candidate := methodName(fullFuncName[:lastDot])
+		if candidate != "" {
+			method = candidate
+		}
+	}
+	return method
+}
+
 // for aws.Logger
 func (l *logHandle) Log(args ...interface{}) {
 	l.Debugln(args...)
diff --git a/pkg/utils/logger_test.go b/pkg/utils/logger_test.go
index 87439a6a2a42..4d4e1d025809 100644
--- a/pkg/utils/logger_test.go
+++ b/pkg/utils/logger_test.go
@@ -58,3 +58,39 @@ func TestLogger(t *testing.T) {
 		t.Fatalf("logid \"testid\" should be logged: %s", s)
 	}
 }
+
+func TestMethodName(t *testing.T) {
+	type args struct {
+		fullFuncName string
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{{
+		name: "main",
+		args: args{
+			fullFuncName: "cmd.Main",
+		},
+		want: "Main",
+	}, {
+		name: "nested method",
+		args: args{
+			fullFuncName: "github.com/juicedata/juicefs/cmd.watchdog.func1",
+		},
+		want: "watchdog",
+	}, {
+		name: "multiple inits",
+		args: args{
+			fullFuncName: "github.com/juicedata/juicefs/pkg/utils.init.3.func1",
+		},
+		want: "init",
+	}}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := methodName(tt.args.fullFuncName); got != tt.want {
+				t.Errorf("methodName() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}