首次提交：初始化项目代码

internal/pkg/logger/logger.go

@@ -0,0 +1,131 @@
+package logger
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// Level represents log level.
+type Level int
+
+const (
+	LevelDebug Level = iota
+	LevelInfo
+	LevelWarn
+	LevelError
+)
+
+func (l Level) String() string {
+	switch l {
+	case LevelDebug:
+		return "DEBUG"
+	case LevelInfo:
+		return "INFO"
+	case LevelWarn:
+		return "WARN"
+	case LevelError:
+		return "ERROR"
+	default:
+		return "INFO"
+	}
+}
+
+// Logger is a simple JSON logger compatible with Go 1.20.
+type Logger struct {
+	level  Level
+	writer io.Writer
+	mu     sync.Mutex
+}
+
+// Default is the global default logger.
+var Default atomic.Value
+
+func init() {
+	Default.Store(&Logger{level: LevelInfo, writer: os.Stderr})
+}
+
+func getDefault() *Logger {
+	if l, ok := Default.Load().(*Logger); ok && l != nil {
+		return l
+	}
+	return &Logger{level: LevelInfo, writer: os.Stderr}
+}
+
+// Init initializes the logger with the specified log level.
+func Init(level string) {
+	InitWithWriter(level, os.Stdout)
+}
+
+// InitWithWriter initializes the logger with the specified log level and writer.
+func InitWithWriter(level string, writer io.Writer) {
+	var lvl Level
+	switch level {
+	case "debug":
+		lvl = LevelDebug
+	case "info":
+		lvl = LevelInfo
+	case "warn":
+		lvl = LevelWarn
+	case "error":
+		lvl = LevelError
+	default:
+		lvl = LevelInfo
+	}
+	if writer == nil {
+		writer = os.Stdout
+	}
+	Default.Store(&Logger{level: lvl, writer: writer})
+}
+
+func (l *Logger) log(level Level, msg string, args ...any) {
+	if level < l.level {
+		return
+	}
+	record := map[string]any{
+		"time":  time.Now().Format(time.RFC3339Nano),
+		"level": level.String(),
+		"msg":   msg,
+	}
+	for i := 0; i < len(args)-1; i += 2 {
+		key, ok := args[i].(string)
+		if !ok {
+			continue
+		}
+		record[key] = args[i+1]
+	}
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	data, _ := json.Marshal(record)
+	fmt.Fprintln(l.writer, string(data))
+}
+
+// Debug logs a message at Debug level.
+func Debug(msg string, args ...any) {
+	getDefault().log(LevelDebug, msg, args...)
+}
+
+// Info logs a message at Info level.
+func Info(msg string, args ...any) {
+	getDefault().log(LevelInfo, msg, args...)
+}
+
+// Warn logs a message at Warn level.
+func Warn(msg string, args ...any) {
+	getDefault().log(LevelWarn, msg, args...)
+}
+
+// Error logs a message at Error level.
+func Error(msg string, args ...any) {
+	getDefault().log(LevelError, msg, args...)
+}
+
+// Fatal logs a message at Error level and exits.
+func Fatal(msg string, args ...any) {
+	getDefault().log(LevelError, msg, args...)
+	os.Exit(1)
+}