概述
項目中要在操作數據庫的異常處理中加入寫Log日志,對於商業上有要求,寫log時對其它操作盡可能影響小,不能因為加入log導致耗時太多。
設計思想
在寫入日志時利用Queue來管理,寫日志有一個專門的backgroud線程來處理,如果沒有日志要寫,這個線程處於wait狀態,這就有了線程的異步處理。
簡單的實現方式
- //<summary>
- //Write Log
- //<summary>
- public static void WriteLog(string logFile, string msg)
- {
- try
- {
- System.IO.StreamWriter sw = System.IO.File.AppendText(
- logPath + LogFilePrefix +" "+ logFile + " " +
- DateTime.Now.ToString("yyyyMMdd") + ".Log"
- );
- sw.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss: ") + msg);
- sw.Close();
- }
- catch (Exception)
- {
- throw;
- }
- }
我們的設計圖
而後我們在AddLogMessage時semaphore.Release()就能喚醒wait中的log 線程。
代碼設計
- /// <summary>
- /// Author: spring yang
- /// Create time:2012/3/30
- /// Log Help class
- /// </summary>
- /// <remarks>High performance log class</remarks>
- public class Log : IDisposable
- {
- //Log Message queue
- private static Queue<LogMessage> _logMessages;
- //log save directory
- private static string _logDirectory;
- //log write file state
- private static bool _state;
- //log type
- private static LogType _logType;
- //log life time sign
- private static DateTime _timeSign;
- //log file stream writer
- private static StreamWriter _writer;
- /// <summary>
- /// Wait enqueue wirte log message semaphore will release
- /// </summary>
- private Semaphore _semaphore;
- /// <summary>
- /// Single instance
- /// </summary>
- private static Log _log;
- /// <summary>
- /// Gets a single instance
- /// </summary>
- public static Log LogInstance
- {
- get { return _log ?? (_log = new Log()); }
- }
- private object _lockObjeck;
- /// <summary>
- /// Initialize Log instance
- /// </summary>
- private void Initialize()
- {
- if (_logMessages == null)
- { _state = true;
- string logPath = System.Configuration.ConfigurationManager.APPSettings["LogDirectory"];
- _logDirectory = string.IsNullOrEmpty(logPath) ? ".\\log\\" : logPath;
- if (!Directory.Exists(_logDirectory)) Directory.CreateDirectory(_logDirectory);
- _logType = LogType.Daily;
- _lockObjeck=new object();
- _semaphore = new Semaphore(0, int.MaxValue, Constants.LogSemaphoreName);
- _logMessages = new Queue<LogMessage>();
- var thread = new Thread(Work) {IsBackground = true};
- thread.Start();
- }
- }
- /// <summary>
- /// Create a log instance
- /// </summary>
- private Log()
- {
- Initialize();
- }
- /// <summary>
- /// Log save name type,default is daily
- /// </summary>
- public LogType LogType
- {
- get { return _logType; }
- set { _logType = value; }
- }
- /// <summary>
- /// Write Log file work method
- /// </summary>
- private void Work()
- {
- while (true)
- {
- //Determine log queue have record need wirte
- if (_logMessages.Count > 0)
- {
- FileWriteMessage();
- }
- else
- if (WaitLogMessage()) break;
- }
- }
- /// <summary>
- /// Write message to log file
- /// </summary>
- private void FileWriteMessage()
- {
- LogMessage logMessage=null;
- lock (_lockObjeck)
- {
- if(_logMessages.Count>0)
- logMessage = _logMessages.Dequeue();
- }
- if (logMessage != null)
- {
- FileWrite(logMessage);
- }
- }
- /// <summary>
- /// The thread wait a log message
- /// </summary>
- /// <returns>is close or not</returns>
- private bool WaitLogMessage()
- {
- //determine log life time is true or false
- if (_state)
- {
- WaitHandle.WaitAny(new WaitHandle[] { _semaphore }, -1, false);
- return false;
- }
- FileClose();
- return true;
- }
- /// <summary>
- /// Gets file name by log type
- /// </summary>
- /// <returns>log file name</returns>
- private string GetFilename()
- {
- DateTime now = DateTime.Now;
- string format = "";
- switch (_logType)
- {
- case LogType.Daily:
- _timeSign = new DateTime(now.Year, now.Month, now.Day);
- _timeSign = _timeSign.AddDays(1);
- format = "yyyyMMdd'.log'";
- break;
- case LogType.Weekly:
- _timeSign = new DateTime(now.Year, now.Month, now.Day);
- _timeSign = _timeSign.AddDays(7);
- format = "yyyyMMdd'.log'";
- break;
- case LogType.Monthly:
- _timeSign = new DateTime(now.Year, now.Month, 1);
- _timeSign = _timeSign.AddMonths(1);
- format = "yyyyMM'.log'";
- break;
- case LogType.Annually:
- _timeSign = new DateTime(now.Year, 1, 1);
- _timeSign = _timeSign.AddYears(1);
- format = "yyyy'.log'";
- break;
- }
- return now.ToString(format);
- }
- /// <summary>
- /// Write log file message
- /// </summary>
- /// <param name="msg"></param>
- private void FileWrite(LogMessage msg)
- {
- try
- {
- if (_writer == null)
- {
- FileOpen();
- }
- else
- {
- //determine the log file is time sign
- if (DateTime.Now >= _timeSign)
- {
- FileClose();
- FileOpen();
- }
- _writer.WriteLine(Constants.LogMessageTime+msg.Datetime);
- _writer.WriteLine(Constants.LogMessageType+msg.Type);
- _writer.WriteLine(Constants.LogMessageContent+msg.Text);
- _writer.Flush();
- }
- }
- catch (Exception e)
- {
- Console.Out.Write(e);
- }
- }
- /// <summary>
- /// Open log file write log message
- /// </summary>
- private void FileOpen()
- {
- _writer = new StreamWriter(Path.Combine(_logDirectory, GetFilename()), true, Encoding.UTF8);
- }
- /// <summary>
- /// Close log file
- /// </summary>
- private void FileClose()
- {
- if (_writer != null)
- {
- _writer.Flush();
- _writer.Close();
- _writer.Dispose();
- _writer = null;
- }
- }
- /// <summary>
- /// Enqueue a new log message and release a semaphore
- /// </summary>
- /// <param name="msg">Log message</param>
- public void Write(LogMessage msg)
- {
- if (msg != null)
- {
- lock (_lockObjeck)
- {
- _logMessages.Enqueue(msg);
- _semaphore.Release();
- }
- }
- }
- /// <summary>
- /// Write message by message content and type
- /// </summary>
- /// <param name="text">log message</param>
- /// <param name="type">message type</param>
- public void Write(string text, MessageType type)
- {
- Write(new LogMessage(text, type));
- }
- /// <summary>
- /// Write Message by datetime and message content and type
- /// </summary>
- /// <param name="dateTime">datetime</param>
- /// <param name="text">message content</param>
- /// <param name="type">message type</param>
- public void Write(DateTime dateTime, string text, MessageType type)
- {
- Write(new LogMessage(dateTime, text, type));
- }
- /// <summary>
- /// Write message ty exception and message type
- /// </summary>
- /// <param name="e">exception</param>
- /// <param name="type">message type</param>
- public void Write(Exception e, MessageType type)
- {
- Write(new LogMessage(e.Message, type));
- }
- #region IDisposable member
- /// <summary>
- /// Dispose log
- /// </summary>
- public void Dispose()
- {
- _state = false;
- }
- #endregion
- }
- /// <summary>
- /// Log Type
- /// </summary>
- /// <remarks>Create log by daily or weekly or monthly or annually</remarks>
- public enum LogType
- {
- /// <summary>
- /// Create log by daily
- /// </summary>
- Daily,
- /// <summary>
- /// Create log by weekly
- /// </summary>
- Weekly,
- /// <summary>
- /// Create log by monthly
- /// </summary>
- Monthly,
- /// <summary>
- /// Create log by annually
- /// </summary>
- Annually
- }
- /// <summary>
- /// Log Message Class
- /// </summary>
- public class LogMessage
- {
- /// <summary>
- /// Create Log message instance
- /// </summary>
- public LogMessage()
- : this("", MessageType.Unknown)
- {
- }
- /// <summary>
- /// Crete log message by message content and message type
- /// </summary>
- /// <param name="text">message content</param>
- /// <param name="messageType">message type</param>
- public LogMessage(string text, MessageType messageType)
- : this(DateTime.Now, text, messageType)
- {
- }
- /// <summary>
- /// Create log message by datetime and message content and message type
- /// </summary>
- /// <param name="dateTime">date time </param>
- /// <param name="text">message content</param>
- /// <param name="messageType">message type</param>
- public LogMessage(DateTime dateTime, string text, MessageType messageType)
- {
- Datetime = dateTime;
- Type = messageType;
- Text = text;
- }
- /// <summary>
- /// Gets or sets datetime
- /// </summary>
- public DateTime Datetime { get; set; }
- /// <summary>
- /// Gets or sets message content
- /// </summary>
- public string Text { get; set; }
- /// <summary>
- /// Gets or sets message type
- /// </summary>
- public MessageType Type { get; set; }
- /// <summary>
- /// Get Message to string
- /// </summary>
- /// <returns></returns>
- public new string ToString()
- {
- return Datetime.ToString(CultureInfo.InvariantCulture) + "\t" + Text + "\n";
- }
- }
- /// <summary>
- /// Log Message Type enum
- /// </summary>
- public enum MessageType
- {
- /// <summary>
- /// unknown type
- /// </summary>
- Unknown,
- /// <summary>
- /// information type
- /// </summary>
- Information,
- /// <summary>
- /// warning type
- /// </summary>
- Warning,
- /// <summary>
- /// error type
- /// </summary>
- Error,
- /// <summary>
- /// success type
- /// </summary>
- Success
- }
Test Case:
- public static void TestLog()
- {
- Log.LogInstance.Write( "Test Message",MessageType.Information);
- Log.LogInstance.Write("one",MessageType.Error);
- Log.LogInstance.Write("two", MessageType.Success);
- Log.LogInstance.Write("three", MessageType.Warning);
- }
運行結果:
接受Mainz的建議,改了部分代碼。
Mainz:http://www.cnblogs.com/Mainz/
原文鏈接:http://www.cnblogs.com/springyangwc/archive/2012/03/30/2425822.Html
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