C++实现简单的日志记录

//dlogger.h

#ifndef DLOGGER_H

#define DLOGGER_H

#include <iostream>

#include <Mutex>

#include <ctime>

#include <string>

extern std::mutex mt;

//用于获取运行时间

class Duration

{

public:

    explicit Duration() : m_start(clock()){}

    inline double duration();

private:

    clock_t m_start;

};

double Duration::duration()

{

    return (double)(clock() - m_start) / CLOCKS_PER_SEC;

}

class DLogger

{

public:

    enum LogLevel

    {

        Log_Info = 0,

        Log_Debug,

        Log_Warning,

        Log_Error,

        Log_Fatal,

        Level_Num

    };

public:

    explicit DLogger(const std::string &dir = "");

    void log(const char* msg, const char* fileName, int line, LogLevel level = Log_Info);

private:

    std::string m_fileName;

    static const std::string m_levelMsg[Level_Num];

};

extern std::mutex mt;

#endif

//dlogger.cpp

#include "dlogger.h"

#include <cstring>

std::mutex mt;

const std::string DLogger::m_levelMsg[Level_Num] =

{

    "Info",

    "Debug",

    "Warning",

    "Error",

    "Fatal"

};

/**

 * 为日志文件提供一个目录，不提供目录则表示当前工作目录

 */

DLogger::DLogger(const std::string &dir)

{

    char buf[64];

    time_t now = time(0);

    tm* ltm = localtime(&now);

    sprintf(buf, "%d-%d-%d.log", ltm->tm_year + 1900, ltm->tm_mon + 1, ltm->tm_mday);

    if(dir.empty())

    {

        m_fileName = buf;

    }

    else

    {

        m_fileName = dir + "\\" + buf;

    }

}

/**

 * 记录日志

 * @param msg      [日志信息]

 * @param fileName [日志信息文件名]

 * @param line     [日志信息所在行]

 * @param level    [日志信息等级]

 */

void DLogger::log(const char* msg, const char* fileName, int line, LogLevel level)

{

    mt.lock();

    FILE* fp = ::fopen(m_fileName.data(), "a+");

    if(!fp)

    {

        mt.unlock();

        return;

    }

    char buf[1024];

    time_t now = time(0);

    tm *ltm = localtime(&now);

    ::sprintf(buf, "%d/%d/%d %d:%d:%d, %s, %d, %s, %s\n",

              1900+ltm->tm_year, ltm->tm_mon, ltm->tm_mday,

              ltm->tm_hour, ltm->tm_min, ltm->tm_sec,

              fileName, line, msg, m_levelMsg[level].data());

    ::fwrite(buf, sizeof(char),strlen(buf), fp);

    ::fclose(fp);

    mt.unlock();

}