add log

examples/log/log_ex.go

@@ -0,0 +1,12 @@
+package main
+
+import "github.com/sunvim/utils/log"
+
+func main() {
+	log.SetPrefix("Hello")
+
+	log.Info("info hello log")
+
+	log.Error("error log")
+
+}

log/log.go

@@ -0,0 +1,198 @@
+// Copyright (c) 2021 mobus [email protected]
+//
+// 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 log
+
+import (
+	"fmt"
+	stdlog "log"
+	"os"
+)
+
+// Logger is a generic logging interface
+type Logger interface {
+	Log(v ...interface{})
+	Logf(format string, v ...interface{})
+}
+
+// Level is a log level
+type Level int
+
+const (
+	// LevelFatal fatal level
+	LevelFatal Level = iota + 1
+	// LevelError error level
+	LevelError
+	// LevelInfo info level
+	LevelInfo
+	// LevelDebug debug level
+	LevelDebug
+)
+
+func (l Level) String() string {
+	switch l {
+	default:
+		return ""
+	case LevelDebug:
+		return "[DBG]"
+	case LevelError:
+		return "[ERR]"
+	case LevelInfo:
+		return "[INF]"
+	case LevelFatal:
+		return "[FTL]"
+	}
+}
+
+var (
+	// the local logger
+	logger Logger = &defaultLogLogger{}
+
+	// default log level is info
+	level = LevelInfo
+
+	prefix = "[Slog]"
+)
+
+type defaultLogLogger struct{}
+
+func (t *defaultLogLogger) Log(v ...interface{}) {
+	stdlog.Print(v...)
+}
+
+func (t *defaultLogLogger) Logf(format string, v ...interface{}) {
+	stdlog.Printf(format, v...)
+}
+
+func init() {
+	switch os.Getenv("SLOG_LOG_LEVEL") {
+	case "debug":
+		level = LevelDebug
+	case "info":
+		level = LevelInfo
+	case "error":
+		level = LevelError
+	case "fatal":
+		level = LevelFatal
+	}
+}
+
+func SetLogPrefix(logName string) {
+	prefix = logName
+}
+
+// Log makes use of Logger
+func Log(v ...interface{}) {
+	if len(prefix) > 0 {
+		logger.Log(append([]interface{}{prefix, " "}, v...)...)
+		return
+	}
+	logger.Log(v...)
+}
+
+// Logf makes use of Logger
+func Logf(format string, v ...interface{}) {
+	if len(prefix) > 0 {
+		format = prefix + " " + format
+	}
+	logger.Logf(format, v...)
+}
+
+// WithLevel logs with the level specified
+func WithLevel(l Level, v ...interface{}) {
+	if l > level {
+		return
+	}
+	Log(v...)
+}
+
+// WithLevelf logs with the level specified
+func WithLevelf(l Level, format string, v ...interface{}) {
+	if l > level {
+		return
+	}
+	Logf(format, v...)
+}
+
+// Debug provides debug level logging
+func Debug(v ...interface{}) {
+	WithLevel(LevelDebug, v...)
+}
+
+// Debugf provides debug level logging
+func Debugf(format string, v ...interface{}) {
+	WithLevelf(LevelDebug, format, v...)
+}
+
+// Info provides info level logging
+func Info(v ...interface{}) {
+	WithLevel(LevelInfo, v...)
+}
+
+// Infof provides info level logging
+func Infof(format string, v ...interface{}) {
+	WithLevelf(LevelInfo, format, v...)
+}
+
+// Error provides warn level logging
+func Error(v ...interface{}) {
+	WithLevel(LevelError, v...)
+}
+
+// Errorf provides warn level logging
+func Errorf(format string, v ...interface{}) {
+	WithLevelf(LevelError, format, v...)
+}
+
+// Fatal logs with Log and then exits with os.Exit(1)
+func Fatal(v ...interface{}) {
+	WithLevel(LevelFatal, v...)
+	os.Exit(1)
+}
+
+// Fatalf logs with Logf and then exits with os.Exit(1)
+func Fatalf(format string, v ...interface{}) {
+	WithLevelf(LevelFatal, format, v...)
+	os.Exit(1)
+}
+
+// SetLogger sets the local logger
+func SetLogger(l Logger) {
+	logger = l
+}
+
+// GetLogger returns the local logger
+func GetLogger() Logger {
+	return logger
+}
+
+// SetLevel sets the log level
+func SetLevel(l Level) {
+	level = l
+}
+
+// GetLevel returns the current level
+func GetLevel() Level {
+	return level
+}
+
+// SetPrefix sets a prefix for the logger
+func SetPrefix(p string) {
+	prefix = p
+}
+
+// Name sets service name
+func Name(name string) {
+	prefix = fmt.Sprintf("[%s]", name)
+}