概述
项目中要在操作数据库的异常处理中加入写Log日志,对于商业上有要求,写log时对其它操作尽可能影响小,不能因为加入log导致耗时太多。
设计思想
在写入日志时利用Queue来管理,写日志有一个专门的backgroud线程来处理,如果没有日志要写,这个线程处于wait状态,这就有了线程的异步处理。
简单的实现方式
复制
//<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; } }
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
我们的设计图
而后我们在AddLogMessage时semaphore.Release()就能唤醒wait中的log 线程。
代码设计
复制
/// <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 }
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
99.
100.
101.
102.
103.
104.
105.
106.
107.
108.
109.
110.
111.
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.
130.
131.
132.
133.
134.
135.
136.
137.
138.
139.
140.
141.
142.
143.
144.
145.
146.
147.
148.
149.
150.
151.
152.
153.
154.
155.
156.
157.
158.
159.
160.
161.
162.
163.
164.
165.
166.
167.
168.
169.
170.
171.
172.
173.
174.
175.
176.
177.
178.
179.
180.
181.
182.
183.
184.
185.
186.
187.
188.
189.
190.
191.
192.
193.
194.
195.
196.
197.
198.
199.
200.
201.
202.
203.
204.
205.
206.
207.
208.
209.
210.
211.
212.
213.
214.
215.
216.
217.
218.
219.
220.
221.
222.
223.
224.
225.
226.
227.
228.
229.
230.
231.
232.
233.
234.
235.
236.
237.
238.
239.
240.
241.
242.
243.
244.
245.
246.
247.
248.
249.
250.
251.
252.
253.
254.
255.
256.
257.
258.
259.
260.
261.
262.
263.
264.
265.
266.
267.
268.
269.
270.
271.
272.
273.
274.
275.
276.
277.
278.
279.
280.
281.
282.
283.
284.
285.
286.
287.
288.
289.
290.
291.
292.
293.
294.
295.
296.
297.
298.
299.
300.
301.
302.
303.
304.
305.
306.
307.
308.
309.
310.
311.
312.
313.
314.
315.
316.
317.
318.
319.
320.
321.
322.
323.
324.
325.
326.
327.
328.
329.
330.
331.
332.
333.
334.
335.
336.
337.
338.
339.
340.
341.
342.
343.
344.
345.
346.
347.
348.
349.
350.
351.
352.
353.
354.
355.
356.
357.
358.
359.
360.
361.
362.
363.
364.
365.
366.
367.
368.
369.
370.
371.
372.
373.
374.
375.
376.
377.
378.
379.
380.
381.
382.
383.
384.
385.
386.
387.
388.
389.
390.
391.
392.
393.
394.
395.
396.
397.
398.
399.
Test Case：
复制
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); }
1.
2.
3.
4.
5.
6.
7.
运行结果：
接受Mainz的建议，改了部分代码。
Mainz：http://www.cnblogs.com/Mainz/
原文链接：http://www.cnblogs.com/springyangwc/archive/2012/03/30/2425822.html
【编辑推荐】