重复造轮子,编写一个轻量级的异步写日志的实用工具类(LogAsyncWriter)

一说到写日志,大家可能推荐一堆的开源日志框架,如:Log4Net、NLog,这些日志框架确实也不错,比较强大也比较灵活,但也正因为又强大又灵活,导致我们使用他们时需要引用一些DLL,同时还要学习各种用法及配置文件,这对于有些小工具、小程序、小网站来说,有点“杀鸡焉俺用牛刀”的感觉,而且如果对这些日志框架不了解,可能输出来的日志性能或效果未毕是与自己所想的,鉴于这几个原因,我自己重复造轮子,编写了一个轻量级的异步写日志的实用工具类(LogAsyncWriter),这个类还是比较简单的,实现思路也很简单,就是把消息日志先入内存队列,然后由异步监听线程从队列中取出日志并批量输出到本地文件中,同时参照各大日志框架,对单个文件过大采取分割生成多个日志文件。

经测试发现性能非常不错,先看示例使用代码:(采取并发多线程同时写入1000000万条日志)

 

            Task.Factory.StartNew(() =>
            {
                DateTime startTime = DateTime.Now;
                int logCount = 1000000;
                Parallel.For(1, logCount, (i) =>
                {
                    if (i % 2 == 0)
                    {
                        LogAsyncWriter.Default.Error("测试并发写错误日志-" + i.ToString(), "TestClass.TestLog", i.ToString());
                    }
                    else
                    {
                        LogAsyncWriter.Default.Info("测试并发写普通日志-" + i.ToString(), "TestClass.TestLog", i.ToString());
                    }
                });

                this.Invoke(new MethodInvoker(() =>
                {
                    MessageBox.Show(DateTime.Now.ToString() + "," + logCount + "条日志写完了!,耗时:" + (DateTime.Now - startTime).TotalMilliseconds + "ms");
                }));
            });

            MessageBox.Show(DateTime.Now.ToString() + ",同步方法已结束");
        }

 执行效果如下图示:

因为采用异步,故方法先走到结尾,输出了同步的MsgBox,随后弹出的是100W日志输出到文件后的耗时MsgBox,从截图可以看出,不足1S(当然这里的1S不是真实的输出到本地方件,而是把所有的日志推到了Queue中而矣,但不影响不阻塞业务处理),而本地日志文件的大小达到了263MB(设置最大值的MaxSizeBackup,使其不滚动备份),由此看性能是不错的;

因为是异步延迟输出到本地日志文件,故大家在代码中任意地方,比如:循环中都可以使用它,不用担心会影响你的正常的业务逻辑的执行效率;

如果采取滚动备份(设置MaxSizeBackup为一个合理值,默认为10MB),则生成的日志文件形式如下:(超过最大容量则生成同名文件+2位序号),超过一个月则会自动清除

打开日志文件会看到所有的日志内容:

有些人可能要问,输出格式是固定的吗?能否自定义布局,告诉你是可以的,我考虑到每个人对日志输出的格式都有严格的要求,故可以通过设置:LineLayoutRenderFormat属性来设置每条日志输出的格式内容

 好了,介绍了使用功能及效果、性能,下面贴出源代码:

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Text.RegularExpressions;

namespace Zuowj.Common
{
    /// <summary>
    /// 日志异步生成器
    /// Author:Zuowenjun(http://www.zuowenjun.cn)
    /// Date:2018-6-14
    /// </summary>
    public class LogAsyncWriter
    {
        public const string InfoLevel = "INFO";
        public const string WarnLevel = "WARN";
        public const string ErrorLevel = "ERROR";

        private readonly ConcurrentQueue<string[]> logMsgQueue = new ConcurrentQueue<string[]>();
        private readonly CancellationTokenSource cts = null;
        private string lineLayoutRenderFormat = "[{0:yyyy-MM-dd HH:mm:ss}]\t{1}\t{2}\t{3}:{4},Trace:{5};Other1:{6},Other2:{7},Other3:{8}";
        private long maxSizeBackup = 10485760L;//默认10MB
        private string todayLogName = null;

        private static readonly LogAsyncWriter instance = new LogAsyncWriter();


        private LogAsyncWriter()
        {
            cts = new CancellationTokenSource();
            ListenSaveLogAsync(cts.Token);
        }

        private void ListenSaveLogAsync(CancellationToken cancellationToken)
        {
            Task.Factory.StartNew(() =>
            {
                DateTime lastSaveLogTime = DateTime.Now;
                while (!cancellationToken.IsCancellationRequested)//如果没有取消线程,则一直监听执行写LOG
                {
                    if (logMsgQueue.Count >= 10 || (logMsgQueue.Count > 0 && (DateTime.Now - lastSaveLogTime).TotalSeconds > 30))//如是待写日志消息累计>=10条或上一次距离现在写日志时间超过30s则需要批量提交日志
                    {
                        List<string[]> logMsgList = new List<string[]>();
                        string[] logMsgItems = null;

                        while (logMsgList.Count < 10 && logMsgQueue.TryDequeue(out logMsgItems))
                        {
                            logMsgList.Add(logMsgItems);
                        }

                        WriteLog(logMsgList);

                        lastSaveLogTime = DateTime.Now;
                    }
                    else
                    {
                        SpinWait.SpinUntil(() => logMsgQueue.Count >= 10, 5000);//自旋等待直到日志队列有>=10的记录或超时5S后再进入下一轮的判断
                    }
                }
            }, cancellationToken);
        }

        private string GetLogFilePath()
        {
            string logFileDir = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Logs");
            if (!Directory.Exists(logFileDir))
            {
                Directory.CreateDirectory(logFileDir);
            }

            string logDateStr = DateTime.Now.ToString("yyyyMMdd");
            string logName = logDateStr;
            if (!string.IsNullOrEmpty(todayLogName) && todayLogName.StartsWith(logName))
            {
                logName = todayLogName;
            }
            else
            {
                todayLogName = logName;
            }

            string logFilePath = Path.Combine(logFileDir, logName + ".log");

            if (File.Exists(logFilePath))
            {
                File.SetAttributes(logFilePath, FileAttributes.Normal);
                if (File.GetLastWriteTime(logFilePath).Month != DateTime.Today.Month) //30天滚动(删除旧的文件),防止日志文件过多
                {
                    File.Delete(logFilePath);
                    string[] oldLogFiles = Directory.GetFiles(logFileDir, string.Format("{0}-##.log", logDateStr), SearchOption.TopDirectoryOnly);
                    foreach (string fileName in oldLogFiles)
                    {
                        File.SetAttributes(fileName, FileAttributes.Normal);
                        File.Delete(fileName);
                    }
                }
                else if (new FileInfo(logFilePath).Length > MaxSizeBackup)
                {
                    Regex rgx = new Regex(@"^\d{8}-(?<fnum>\d{2})$");
                    int fnum = 2;
                    if (rgx.IsMatch(logName))
                    {
                        fnum = int.Parse(rgx.Match(logName).Groups["fnum"].Value) + 1;
                    }

                    logName = string.Format("{0}-{1:D2}", logDateStr, fnum);
                    todayLogName = logName;
                    logFilePath = Path.Combine(logFileDir, logName + ".log");
                }
            }

            return logFilePath;
        }

        private void WriteLog(IEnumerable<string[]> logMsgs)
        {
            try
            {
                List<string> logMsgLines = new List<string>();
                foreach (var logMsgItems in logMsgs)
                {
                    var logMsgLineFields = (new object[] { DateTime.Now }).Concat(logMsgItems).ToArray();
                    string logMsgLineText = string.Format(LineLayoutRenderFormat, logMsgLineFields);
                    logMsgLines.Add(logMsgLineText);
                }

                string logFilePath = GetLogFilePath();
                File.AppendAllLines(logFilePath, logMsgLines);
            }
            catch
            { }
        }



        public static LogAsyncWriter Default
        {
            get
            {
                return instance;
            }
        }

        public string LineLayoutRenderFormat
        {
            get { return lineLayoutRenderFormat; }
            set
            {
                if (string.IsNullOrWhiteSpace(value))
                {
                    throw new ArgumentException("无效的LineLayoutRenderFormat属性值");
                }

                lineLayoutRenderFormat = value;
            }
        }

        public long MaxSizeBackup
        {
            get { return maxSizeBackup; }
            set
            {
                if (value <= 0)
                {
                    throw new ArgumentException("无效的MaxSizeBackup属性值");
                }

                maxSizeBackup = value;
            }
        }

        public void SaveLog(string logLevel, string msg, string source, string detailTrace = null, string other1 = null, string other2 = null, string other3 = null)
        {
            logMsgQueue.Enqueue(new[] { logLevel, Thread.CurrentThread.ManagedThreadId.ToString(), source, msg, detailTrace ?? string.Empty, other1 ?? string.Empty, other2 ?? string.Empty, other3 ?? string.Empty });
        }

        public void Info(string msg, string source, string detailTrace = null, string other1 = null, string other2 = null, string other3 = null)
        {
            SaveLog(InfoLevel, msg, source, detailTrace, other1, other2, other3);
        }

        public void Warn(string msg, string source, string detailTrace = null, string other1 = null, string other2 = null, string other3 = null)
        {
            SaveLog(WarnLevel, msg, source, detailTrace, other1, other2, other3);
        }

        public void Error(string msg, string source, string detailTrace = null, string other1 = null, string other2 = null, string other3 = null)
        {
            SaveLog(ErrorLevel, msg, source, detailTrace, other1, other2, other3);
        }

        public void Error(Exception ex, string source, string other1 = null, string other2 = null, string other3 = null)
        {
            SaveLog(ErrorLevel, ex.Message, source, ex.StackTrace, other1, other2, other3);
        }

        ~LogAsyncWriter()
        {
            cts.Cancel();
        }

    }
}

 代码重点说明:

1.各种日志方法入参解释:

i. Msg:日志消息(一般是指简要消息)
ii. Source:日志产生源(一般是指该日志是由哪个位置产生的,可以定义为:类.方法名)
iii. detailTrace:日志详情(一般是指堆栈信息或日志更具体的信息)
iv. other1, other2, other3:备用日志字段,可根据实际情况记录相关信息,比如:入参、返参,执行耗时等;
v. log Level:日志消息级别一般有很多级别,但常用的只有3类,即:Info=普通日志消息,Warn=警告日志消息,Error=错误日志消息;

2.核心异步批量写日志的方法:(采用后台线程监听日志消息队列,当达到10条日志消息或写日志的时间间隔超过1分钟,则会批量提交1次日志,解决了普通的同步写日志方法造成写压力过大,且存在阻塞业务逻辑的情况)

3.采用单例模式,当第一次使用该类时,则会启动异步监听线程,当该类释放时(一般指应用进程关闭时,会发送通知线程取消监听,避免一切可能的线程驻留问题)

 

好了就介绍到这里,大家若想试用或想改造,可以直接复制上述代码,不足之处可以指出,谢谢!

 

posted @ 2018-06-14 16:07 梦在旅途 阅读(...) 评论(...) 编辑 收藏