使用变长参数实现简单的日志类

做项目时候经常需要打印日志来输出一些重要的信息，自己实现了一个简单的日志类，记录下。

Log.h

 1 #pragma once
 2 
 3 class CVxILog
 4 {
 5 private:
 6     CVxILog();
 7     ~CVxILog();
 8 public:
 9     static    CVxILog*        Instance()
10     {
11         static CVxILog    log;
12         return &log;
13     }
14 
15     void    AddLog(const char* msg);
16 
17     void    AddLogEx(const char* format, ...);
18 private:
19     static const    char* m_pFileName;
20 
21     static CRITICAL_SECTION    s_cs;
22 };
23 
24 #define WRITE_LOG(msg)                    CVxILog::Instance()->AddLog(msg)
25 #define WRITE_LOG_EX(format,...)    CVxILog::Instance()->AddLogEx(format,__VA_ARGS__)

Log.cpp

 1 #include "stdafx.h"
 2 #include "Log.h"
 3 #include <fstream>
 4 
 5 CRITICAL_SECTION    CVxILog::s_cs;
 6 
 7 const char* CVxILog::m_pFileName = _T("Test.log");
 8 
 9 #define MAX_LOG_LENGTH        1024        //最大Log长度
10 
11 static void    WriteHeadStr(std::ofstream& out)
12 {
13     SYSTEMTIME st = {0};
14     GetLocalTime(&st);
15     char timeStr[MAX_LOG_LENGTH] = {0};
16     sprintf_s(timeStr,"[%d-%02d-%02d %02d:%02d:%02d] ",st.wYear,st.wMonth,st.wDay,st.wHour,st.wMinute,st.wSecond);
17     out << timeStr;
18 }
19 
20 CVxILog::CVxILog()
21 {
22     ::InitializeCriticalSection(&s_cs);
23 }
24 CVxILog::~CVxILog()
25 {
26     ::DeleteCriticalSection(&s_cs);
27 }
28 
29 void    CVxILog::AddLog(const char* msg)
30 {
31     ::EnterCriticalSection(&s_cs);
32     std::ofstream    out;
33     out.open(m_pFileName,std::ios_base::app|std::ios_base::out);
34     if(out.is_open())
35     {
36         WriteHeadStr(out);
37         out << msg << std::endl;
38         out.close();
39     }
40     ::LeaveCriticalSection(&s_cs);
41 }
42 
43 void    CVxILog::AddLogEx(const char* format, ...)
44 {
45     ::EnterCriticalSection(&s_cs);
46     std::ofstream    out;
47     out.open(m_pFileName,std::ios_base::app|std::ios_base::out);
48     if(out.is_open())
49     {
50         WriteHeadStr(out);
51 
52         va_list ap;
53         va_start(ap,format);
54         char msg[MAX_LOG_LENGTH];
55         int size = vsnprintf_s(msg,MAX_LOG_LENGTH-1,format,ap);
56         if(size > 0)
57         {
58             out << msg << std::endl;
59         }
60         va_end(ap);
61         
62         out.close();
63     }
64     ::LeaveCriticalSection(&s_cs);
65 }

使用时可以

1 WRITE_LOG("log test");
2 WRITE_LOG_EX("[%s],log test",__FUNCTION__);

基本满足使用，但是还有很多不足，欢迎大家批评指正