新写的一个日志接口

主要是为了记录宏中使用可变参数。如果没有可变参数，也不会有逗号的影响。 主要是##grgs的使用，至于具体gnu gcc版本对可变参数的支持程度，尚未进行充分测试。

头文件

#pragma once

#include <string>

typedef void (*LogCallBack)(unsigned short logType, const char* log);

void set_log_callback(LogCallBack callback);

void set_log_type_of_info(unsigned short logType);
void set_log_type_of_trace(unsigned short logType);
void set_log_type_of_debug(unsigned short logType);
void set_log_type_of_error(unsigned short logType);

void log_write(const char* file, const char* function, int line, unsigned short logType, const char* fmt, ...);
void log_info(const char* file, const char* function, int line, const char* fmt, ...);
void log_trace(const char* file, const char* function, int line, const char* fmt, ...);
void log_debug(const char* file, const char* function, int line, const char* fmt, ...);
void log_error(const char* file, const char* function, int line, const char* fmt, ...);

#define log_WRITE(logType, format, args...) 
    log_write(__FILE__,__FUNCTION__, __LINE__, logType, format, ##args)

#define log_INFO(format, args...) 
    log_info(__FILE__,__FUNCTION__, __LINE__, format, ##args)

#define log_TRACE(format, args...) 
    log_trace(__FILE__,__FUNCTION__, __LINE__, format, ##args)

#define log_DEBUG(format, args...) 
    log_debug(__FILE__,__FUNCTION__, __LINE__, format, ##args)

#define log_ERROR(format, args...) 
    log_error(__FILE__,__FUNCTION__, __LINE__, format, ##args)

源文件：

#include "Log.h"

#include <stdarg.h>
#include <sstream>
#include <stdio.h>
#include "string.h"

using namespace std;

static LogCallBack callback_function = NULL;

static unsigned short log_info     = 0;
static unsigned short log_trace    = 0;
static unsigned short log_debug    = 0;
static unsigned short log_error    = 0;

static void write_log(unsigned short logType, const char* file,
                const char* function, int line, const char* fmt, va_list args);

void log_write(const char* file, const char* function, int line, unsigned short logType, const char* fmt, ...)
{    
    if (NULL == callback_function)
    {
        return;
    }
    
    va_list arguments;
    va_start(arguments, fmt);
    write_log(logType, file, function, line, fmt, arguments);    
    va_end(arguments);
}

void log_info(const char* file, const char* function, int line, const char* fmt, ...)
{    
    if (NULL == callback_function)
    {
        return;
    }
    
    va_list arguments;
    va_start(arguments, fmt);
    write_log(log_info, file, function, line, fmt, arguments);    
    va_end(arguments);
}

void log_trace(const char* file, const char* function, int line, const char* fmt, ...)
{    
    if (NULL == callback_function)
    {
        return;
    }
    
    va_list arguments;
    va_start(arguments, fmt);
    write_log(log_trace, file, function, line, fmt, arguments);    
    va_end(arguments);
}

void log_debug(const char* file, const char* function, int line, const char* fmt, ...)
{    
    if (NULL == callback_function)
    {
        return;
    }
    
    va_list arguments;
    va_start(arguments, fmt);
    write_log(log_debug, file, function, line, fmt, arguments);    
    va_end(arguments);
}

void log_error(const char* file, const char* function, int line, const char* fmt, ...)
{    
    if (NULL == callback_function)
    {
        return;
    }
    
    va_list arguments;
    va_start(arguments, fmt);
    write_log(log_error, file, function, line, fmt, arguments);    
    va_end(arguments);
}

void set_log_callback(LogCallBack callback)
{
    callback_function = callback;
}

void set_log_type_of_info(unsigned short logType)
{
    log_info = logType;
}

void set_log_type_of_debug(unsigned short logType)
{
    log_debug = logType;
}

void set_log_type_of_trace(unsigned short logType)
{
    log_trace = logType;
}

void set_log_type_of_error(unsigned short logType)
{
    log_error = logType;
}

static void write_log(unsigned short logType, const char* file,
                const char* function, int line, const char* fmt, va_list args)
{
    char chArr[2048];
    memset(chArr, 0 , sizeof(chArr));
    
    vsnprintf(chArr, 2047, fmt, args); 
    
    stringstream oss;
    oss<<file<<"::"<<function<<"::"<<line<<"::"<<chArr<<"
"<<endl;
        
    callback_function(logType, oss.str().c_str()); 
}