【原创】go语言学习（十七）接口应用实战--日志库

目前

• 日志库需求分析
• 日志库接口设计
• 文件日志库开发
• Console日志开发
• 日志使用以及测试

日志库需求分析

1、日志库需求分析

A. 程序运行是个黑盒
B. 而日志是程序运行的外在表现
C. 通过日志，可以知道程序的健康状态

2、日志库需求分析

A. Debug级别：用来调试程序，日志最详细。对程序性能影响比较大。
B. Trace级别：用来追踪问题。
C. Info级别：打印程序运行过程中比较重要的信息，比如访问日志
D. Warn级别：警告日志，说明程序运行出现了潜在的问题
E. Error级别：错误日志，程序运行发生错误，但不影响程序运行。
F. Fatal级别：严重错误日志，发生的错误会导致程序退出

3、日志库需求分析

A. 直接输出到控制台
B. 打印到文件里
C. 直接打印到网络中，比如kafka

日志库接口设计

1、为什么使用接口?

A. 定义日志库的规范或者标准
B. 易于可扩展性
C. 利于程序的可维护性

2、 日志库设计

A. 打印各个level的日志
B. 设置级别
C. 构造函数

文件日志库开发

1、关键代码

package logger

import (
	"fmt"
	"os"
	"strconv"
	"time"
)

type FileLogger struct {
	level    int
	logPath  string
	logName  string
	file     *os.File
	warnFile *os.File
	// 异步通道
	LogDataChan chan *LogData
	// 日志切分
	logSplitType  int
	logSplitSize  int64
	lastSplitHour int
}

func NewFileLogger(config map[string]string) (log LogInterface, err error) {
	logPath, ok := config["log_path"]
	if !ok {
		err = fmt.Errorf("not found log_path")
		return
	}
	logName, ok := config["log_name"]
	if !ok {
		err = fmt.Errorf("not found log_name")
		return
	}
	logLevel, ok := config["log_level"]
	if !ok {
		err = fmt.Errorf("not found log_level")
		return
	}
	level := getLogLevel(logLevel)

	// 异步管道初始化
	logChanSize, ok := config["log_chan_size"]
	if !ok {
		logChanSize = "50000"
	}
	//检查logChanSize转数字
	chanSize, err := strconv.Atoi(logChanSize)
	if err != nil {
		chanSize = 50000
	}

	//日志切片
	var logSplitType int = LogSplitTypeHour
	var logSplitSize int64
	logSplitStr, ok := config["log_plit_type"]
	if !ok {
		logSplitStr = "hour"
	} else {
		if logSplitStr == "size" {
			logSplitSizeStr, ok := config["log_split_size"]
			if !ok {
				logSplitSizeStr = "104857600"
			}

			logSplitSize, err = strconv.ParseInt(logSplitSizeStr, 10, 64)
			if err != nil {
				logSplitSize = 104857600
			}

			logSplitType = LogSplitTypeSize
		} else {
			logSplitType = LogSplitTypeHour
		}
	}

	log = &FileLogger{
		level:   level,
		logPath: logPath,
		logName: logName,
		// 异步写日志
		LogDataChan: make(chan *LogData, chanSize),
		// 日志切分
		logSplitSize:  logSplitSize,
		logSplitType:  logSplitType,
		lastSplitHour: time.Now().Hour(),
	}

	// 调试日志分割
	// fmt.Println(logSplitSize, logSplitType, logSplitStr)

	log.Init()
	return
}

func (f *FileLogger) SetLevel(level int) {
	if level < LogLevelDebug || level > LogLevelFatal {
		level = LogLevelDebug
	}
	f.level = level
}

func (f *FileLogger) Init() {
	filename := fmt.Sprintf("%s/%s.log", f.logPath, f.logName)
	file, err := os.OpenFile(filename, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0755)
	if err != nil {
		panic(fmt.Sprintf("open faile %s failed, err:%v", filename, err))
	}

	f.file = file

	// 写错误日志和fatal日志文件
	filename = fmt.Sprintf("%s/%s.log.wf", f.logPath, f.logName)
	file, err = os.OpenFile(filename, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0755)
	if err != nil {
		panic(fmt.Sprintf("open faile %s failed, err:%v", filename, err))
	}
	f.warnFile = file
	go f.writeLogBackground()
}

func (f *FileLogger) splitFileHour(warnFile bool) {
	now := time.Now()
	hour := now.Hour()
	if hour == f.lastSplitHour {
		return
	}

	f.lastSplitHour = hour
	var backupFilename string
	var filename string

	if warnFile {
		backupFilename = fmt.Sprintf("%s/%s.log.wf_%4d%02d%02d%02d",
			f.logPath, f.logName, now.Year(), now.Month(), now.Day(), f.lastSplitHour)

		filename = fmt.Sprintf("%s/%s.log.wf", f.logPath, f.logName)
	} else {
		backupFilename = fmt.Sprintf("%s/%s.log_%4d%02d%02d%02d",
			f.logPath, f.logName, now.Year(), now.Month(), now.Day(), f.lastSplitHour)
		filename = fmt.Sprintf("%s/%s.log", f.logPath, f.logName)
	}

	file := f.file
	if warnFile {
		file = f.warnFile
	}

	file.Close()
	os.Rename(filename, backupFilename)

	file, err := os.OpenFile(filename, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0755)
	if err != nil {
		return
	}

	if warnFile {
		f.warnFile = file
	} else {
		f.file = file
	}
}

func (f *FileLogger) splitFileSize(warnFile bool) {

	file := f.file
	if warnFile {
		file = f.warnFile
	}

	statInfo, err := file.Stat()
	if err != nil {
		return
	}

	fileSize := statInfo.Size()
	if fileSize <= f.logSplitSize {
		return
	}

	var backupFilename string
	var filename string

	now := time.Now()
	if warnFile {
		backupFilename = fmt.Sprintf("%s/%s.log.wf_%4d%02d%02d%02d%02d%02d",
			f.logPath, f.logName, now.Year(), now.Month(), now.Day(), now.Hour(), now.Minute(), now.Second())

		filename = fmt.Sprintf("%s/%s.log.wf", f.logPath, f.logName)
	} else {
		backupFilename = fmt.Sprintf("%s/%s.log_%4d%02d%02d%02d",
			f.logPath, f.logName, now.Year(), now.Month(), now.Day(), now.Hour(), now.Minute(), now.Second())
		filename = fmt.Sprintf("%s/%s.log", f.logPath, f.logName)
	}

	file.Close()
	os.Rename(filename, backupFilename)

	file, err = os.OpenFile(filename, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0755)
	if err != nil {
		return
	}

	if warnFile {
		f.warnFile = file
	} else {
		f.file = file
	}
}

func (f *FileLogger) checkSplitFile(warnFile bool) {
	if f.logSplitType == LogSplitTypeHour {
		f.splitFileHour(warnFile)
		return
	}

	f.splitFileSize(warnFile)
}

func (f *FileLogger) writeLogBackground() {
	for data := range f.LogDataChan {
		var file *os.File = f.file
		if data.WarnAndFatal {
			file = f.warnFile
		}

		f.checkSplitFile(data.WarnAndFatal)

		fmt.Fprintf(file, "%s %s (%s:%s:%d) %s
",
			data.LevelStr, data.FileName, data.FuncName, data.LineNo,
			data.Message)
	}
}

func (f *FileLogger) Debug(format string, args ...interface{}) {
	if f.level > LogLevelDebug {
		return
	}
	logData := writeLog(LogLevelDebug, format, args...)
	// 判断队列有没有满
	select {
	case f.LogDataChan <- logData:
	default:
	}
}

func (f *FileLogger) Trace(format string, args ...interface{}) {
	if f.level > LogLevelTrace {
		return
	}
	logData := writeLog(LogLevelTrace, format, args...)
	// 判断队列有没有满
	select {
	case f.LogDataChan <- logData:
	default:
	}

}

func (f *FileLogger) Info(format string, args ...interface{}) {
	if f.level > LogLevelInfo {
		return
	}
	logData := writeLog(LogLevelInfo, format, args...)
	// 判断队列有没有满
	select {
	case f.LogDataChan <- logData:
	default:
	}

}

func (f *FileLogger) Warn(format string, args ...interface{}) {
	if f.level > LogLevelWarn {
		return
	}
	logData := writeLog(LogLevelWarn, format, args...)
	// 判断队列有没有满
	select {
	case f.LogDataChan <- logData:
	default:
	}
}

func (f *FileLogger) Fatal(format string, args ...interface{}) {
	if f.level > LogLevelFatal {
		return
	}
	logData := writeLog(LogLevelFatal, format, args...)
	// 判断队列有没有满
	select {
	case f.LogDataChan <- logData:
	default:
	}

}

func (f *FileLogger) Error(format string, args ...interface{}) {
	if f.level > LogLevelError {
		return
	}
	logData := writeLog(LogLevelError, format, args...)
	// 判断队列有没有满
	select {
	case f.LogDataChan <- logData:
	default:
	}

}

func (f *FileLogger) Close() {
	f.file.Close()
	f.warnFile.Close()
}

Console日志开发

1、关键代码

package logger

import (
	"fmt"
	"os"
)

type ConsoleLogger struct {
	level int
}

func NewConsoleLogger(config map[string]string) (log LogInterface, err error) {
	logLevel, ok := config["log_level"]
	if !ok {
		err = fmt.Errorf("not found log_level")
		return
	}
	level := getLogLevel(logLevel)
	log = &ConsoleLogger{
		level: level,
	}
	return
}

func (c *ConsoleLogger) Init() {

}

func (c *ConsoleLogger) SetLevel(level int) {
	if level < LogLevelDebug || level > LogLevelFatal {
		level = LogLevelDebug
	}
	c.level = level
}

func (c *ConsoleLogger) Debug(format string, args ...interface{}) {
	if c.level > LogLevelDebug {
		return
	}
	logData := writeLog(LogLevelDebug, format, args...)
	fmt.Fprintf(os.Stdout, "%s %s (%s:%s:%d) %s
",
		logData.LevelStr, logData.FileName, logData.FuncName, logData.LineNo,
		logData.Message)
}

func (c *ConsoleLogger) Trace(format string, args ...interface{}) {
	if c.level > LogLevelTrace {
		return
	}
	logData := writeLog(LogLevelTrace, format, args...)
	fmt.Fprintf(os.Stdout, "%s %s (%s:%s:%d) %s
",
		logData.LevelStr, logData.FileName, logData.FuncName, logData.LineNo,
		logData.Message)

}

func (c *ConsoleLogger) Info(format string, args ...interface{}) {
	if c.level > LogLevelInfo {
		return
	}
	logData := writeLog(LogLevelInfo, format, args...)
	fmt.Fprintf(os.Stdout, "%s %s (%s:%s:%d) %s
",
		logData.LevelStr, logData.FileName, logData.FuncName, logData.LineNo,
		logData.Message)

}

func (c *ConsoleLogger) Warn(format string, args ...interface{}) {
	if c.level > LogLevelWarn {
		return
	}
	logData := writeLog(LogLevelWarn, format, args...)
	fmt.Fprintf(os.Stdout, "%s %s (%s:%s:%d) %s
",
		logData.LevelStr, logData.FileName, logData.FuncName, logData.LineNo,
		logData.Message)

}

func (c *ConsoleLogger) Fatal(format string, args ...interface{}) {
	if c.level > LogLevelFatal {
		return
	}
	logData := writeLog(LogLevelFatal, format, args...)
	fmt.Fprintf(os.Stdout, "%s %s (%s:%s:%d) %s
",
		logData.LevelStr, logData.FileName, logData.FuncName, logData.LineNo,
		logData.Message)

}

func (c *ConsoleLogger) Error(format string, args ...interface{}) {
	if c.level > LogLevelError {
		return
	}
	logData := writeLog(LogLevelError, format, args...)
	fmt.Fprintf(os.Stdout, "%s %s (%s:%s:%d) %s
",
		logData.LevelStr, logData.FileName, logData.FuncName, logData.LineNo,
		logData.Message)

}

func (c *ConsoleLogger) Close() {
}

　　

日志使用以及测试

1、关键代码

package logger

import "testing"

// run test| debug test
func TestFileLogger(t *testing.T) {
	logger := NewFileLogger(LogLevelDebug, "d:/logs/", "test")
	logger.Debug("user id[%d] is come from chaina", 3242342)
	logger.Warn("test warn log")
	logger.Fatal("test fatal log")
	logger.Close()
}

// run test| debug test
func TestConsoleLogger(t *testing.T) {
	logger := NewConsoleLogger(LogLevelDebug)
	logger.Debug("user id[%d] is come from chaina", 3242342)
	logger.Warn("test warn log")
	logger.Fatal("test fatal log")
	logger.Close()
}