log4cplus server client模式、log4cplus、log4cplus库（三）(将日志写入到文件)

转载地址1：http://blog.csdn.net/dds_dev_group/article/details/6973847

转载地址2：http://blog.csdn.net/guang11cheng/article/details/7400134

转载地址3：http://www.cppblog.com/API/archive/2011/04/02/143281.html

一、log4cplus server client模式

在多进程使用log4cplus同时向一个日志文件写的时候，官方的FAQ建议使用SoskcetAppender, 即以server client模式来写日志，保证写日志同步。

写了一个小程序，fork出一个server进程，和5个client进程来写日志，当日志大小到达4G的时候做切割。

 /*
  * =====================================================================================
  *
  *       Filename:  multiprocesslog.cpp
  *
  *    Description:
  *
  *        Version:  1.0
  *        Created:  11/15/2011 02:48:44 PM
  *       Revision:  none
  *       Compiler:  gcc
  *
  *         Author:  Xu Zhe Ming,
  *        Company:
  *
  * =====================================================================================
  */

 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include

 using namespace log4cplus;
 using namespace std;
 using namespace log4cplus::helpers;

 //server端
 int log_server(int port)
 {
     //创建一个socket，绑定端口
     helpers::ServerSocket serverSocket(port);
     Logger debug_logger;
     Logger info_logger;

     //注意int会溢出
     long log_size = long(1024) * 1024 * 1024 * 4;

     //初始化一个debug logger，并绑定到一个文件
     {
     SharedAppenderPtr pFileAppender_normal(new RollingFileAppender(("log_file_debug") , log_size, 10));
     debug_logger = Logger::getInstance("debug_logger");
     debug_logger.addAppender(pFileAppender_normal);
     }

     //初始化一个info logger，并绑定到一个文件
     {
     SharedAppenderPtr pFileAppender_normal(new RollingFileAppender(("log_file_info") , log_size, 10));
     info_logger = Logger::getInstance("info_logger");
     info_logger.addAppender(pFileAppender_normal);
     }

     //初始化其他的logger，如warn, error, fatal
     //...

     while(1)
     {
     //accept
     helpers::Socket clientsock = serverSocket.accept();
     SocketBuffer msgSizeBuffer(sizeof(unsigned int));
     if(!clientsock.read(msgSizeBuffer))
     {
         return 0;
     }
     unsigned int msgSize = msgSizeBuffer.readInt();
     SocketBuffer buffer(msgSize);
     //读取日志消息到buffer
     if(!clientsock.read(buffer))
     {
         return 0;
     }

     //转化成event
     spi::InternalLoggingEvent event = readFromBuffer(buffer);
     int level = event.getLogLevel();
     //判断日志的level
     if(level == DEBUG_LOG_LEVEL)
     {
         debug_logger.callAppenders(event);
     }
     else if(level == INFO_LOG_LEVEL)
     {
         info_logger.callAppenders(event);
     }
     //...
     }

     return 0;
 }

 //client端
 int log_client(string server_ip, int server_port)
 {
     SharedAppenderPtr _append(new SocketAppender(server_ip, server_port, "ServerName"));
     Logger::getRoot().addAppender(_append);
     while(1)
     {
     int rand_num = rand();
     int remainder = rand_num % 2;
     if (remainder == 0)
         LOG4CPLUS_INFO(Logger::getRoot(), "client logging event number ... ");
     else
         LOG4CPLUS_DEBUG(Logger::getRoot(), "client logging odd number... ");
     //sleep(1);
     }
 }


 int main()
 {

     pid_t pid = fork();

     //child, let's run a log server process
     if(pid == 0)
     {
     log_server(20000);
     }
     //parent, let's fork some more processes to write logs
     else
     {
     for(int i = 0; i < 5; i++)
     {
         pid = fork();
         //child, let's run a log client process
         if(pid == 0)
         {
         log_client("localhost", 20000);
         }
     }
     }

     while(1)
     {
     sleep(1);
     }

     return 0;
 }