C++类设计：一个比较复杂的日志类支持多线程、文件切换、信息缓存（源码）

初级代码游戏的专栏介绍与文章目录-CSDN博客

github位置：codetoys/ctfc.git src/env/myLog.h和.cpp

这个类功能细节比较多，因为是长期使用的版本，累积了各种功能。之前介绍的两个是我的测试代码用的版本，非常简单，那两个在这里：

C++类设计：设计一个日志类（源码）_初级代码游戏的博客-CSDN博客

C++类设计：一个不同版本的日志类（完整源码）_初级代码游戏的博客-CSDN博客

其实这个版本跟上面两个很不一样，这个版本是基于unix/linux的（64位），控制台程序，支持多线程（需要链接pthread），支持日志文件切换，统计各种信息的条数，能缓存信息，可用于如果一段代码正确结束就不输出、出错才输出。

一、完整源码

二、详解

2.1 关于endi、ende、endr

2.2 多线程支持

2.3 缓存支持

2.4 日志切换

一、完整源码

头文件：

	//输出信息所在位置的日志宏------g_pEnv->GetLog()返回Log，可以直接定义为全局变量
#define thelog ((g_pEnv->GetLog()).LogPos(__FILE__,__LINE__,__func__))
#define theLog (g_pEnv->GetLog())  //不带文件名行号函数名//输出调试信息的宏，G_DEBUG G_TRANCE可以直接定义为全局变量
#define DEBUG_LOG if(G_DEBUG)thelog
#define TRANCE_LOG if(G_TRANCE)thelog////日至struct LogEnd{enum { fENDE = 1, fENDW, fENDI, fENDF, fENDD };char end;LogEnd(int ,int n):end(n){}};ostream & operator<<(ostream & s, LogEnd const & end);//这个好像没啥用，但是我暂时没验证，不敢删LogEnd const ende(0, LogEnd::fENDE); // errorLogEnd const endw(0, LogEnd::fENDW); // warningLogEnd const endi(0, LogEnd::fENDI); // informationLogEnd const endf(0, LogEnd::fENDF); // fatalLogEnd const endd(0, LogEnd::fENDD); // debugclass Log{private://线程数据struct _ThreadSpec{long m_thread_id;stringstream m_buf;string m_strSource;bool m_bOutputThis;//仅控制当前一行输出string m__file;long m__line;string m__func;_ThreadSpec() :m_thread_id(0), m_bOutputThis(true), m__line(0) {}};static void _CloseThreadSpec(void * _p){_ThreadSpec * p=(_ThreadSpec *)_p;delete p;}_ThreadSpec * _getThreadSpec(){_ThreadSpec * p = (_ThreadSpec *)pthread_getspecific(tsd_key);if (p)return p;else{p = new _ThreadSpec;if (!p){throw "new _ThreadSpec return NULL";}m_mutex.lock();p->m_thread_id = m_thread_count;++m_thread_count;m_mutex.unlock();if (0 == pthread_setspecific(tsd_key, p)){return p;}else{throw "pthread_setspecific error";}}}private:long m_thread_count;//线程计数pthread_key_t tsd_key;//线程存储key	CPThreadMutex m_mutex;string m_appname;//用来构造m_filename，用于定时切换文件，若未设置则直接使用m_filenamestring m_appname_old;//切换日志时用来保存原来的，以便切换换回来string m_filename;//当前的日志文件名ofstream m_ofs;bool m_bOutput;//控制所有输出bool m_bCache;//当!m_bOutput时缓存输出结果string::size_type m_maxcache;//最大缓存的数目string m_cache;//缓存的输出void(*m_pUD)(const string& strLog);//用户定义的函数，输出的时候会执行一次，一般也不用//错误和警告统计long countw;long counte;long countall;//正常记录统计long countn;public://设置用户定义的函数，输出的时候会执行一次，一般也不用void SetUserFunction(void(*pUD)(const string& strLog)) { m_pUD = pUD; }public:Log(){m_thread_count = 0;pthread_key_create(&tsd_key, _CloseThreadSpec);m_mutex.init();SetSource("应用");m_bOutput = true;m_bCache = false;m_maxcache = 0;m_pUD = NULL;countw = 0;counte = 0;countn = 0;countall = 0;}void GetCount(long & c_w, long & c_e, long & c_all)const { c_w = countw; c_e = counte; c_all = countall; }string const &GetFileName()const { return m_filename; }Log& LogPos(char const * file, long line,char const * func){string tmp = file;string::size_type pos = tmp.find_last_of("/");if (pos != tmp.npos)_getThreadSpec()->m__file = tmp.substr(pos + 1);else _getThreadSpec()->m__file = file;_getThreadSpec()->m__line = line;_getThreadSpec()->m__func = func;return *this;}string const & _makesource(string const & source, string & ret);template <typename T>Log& operator<<(T const& t){_getThreadSpec()->m_buf << (t);return *this;}Log& operator<<(stringstream const& ss){_getThreadSpec()->m_buf << ss.str();return *this;}Log & operator<<(ostream &(*p)(ostream &)){_getThreadSpec()->m_buf <<(p);return *this;}Log & operator<<(LogEnd const & end){m_mutex.lock();_ThreadSpec * ThreadSpec = _getThreadSpec();char nCh = end.end;bool isImportant = false;string strType;switch (nCh){case LogEnd::fENDI:strType = "[信息]";++countn;break;case LogEnd::fENDW:strType = "[警告]";isImportant = true;++countw;break;case LogEnd::fENDE:strType = "[出错]";isImportant = true;++counte;break;case LogEnd::fENDF:strType = "[致命]";isImportant = true;break;case LogEnd::fENDD:strType = "[调试]";break;}if (isImportant)++countall;time_t t;tm const * t2;char buf[2048];time(&t);t2 = localtime(&t);sprintf(buf, "%02d-%02d %02d:%02d:%02d", t2->tm_mon + 1, t2->tm_mday, t2->tm_hour, t2->tm_min, t2->tm_sec);string strTime = buf;strTime = "[" + strTime + "]";//若未设置则不输出文件名和行号if (0 != ThreadSpec->m__file.size()){sprintf(buf, "[%-24s:%4ld(%s)][%6.2f]", ThreadSpec->m__file.c_str(), ThreadSpec->m__line, ThreadSpec->m__func.c_str(), (clock() / (float)CLOCKS_PER_SEC));}else buf[0] = '\0';string tmpSource;string strMsg;strMsg = strTime + _makesource(ThreadSpec->m_strSource, tmpSource) + strType + buf + ThreadSpec->m_buf.str();if (LogEnd::fENDE == nCh){if (G_ERROR_MESSAGE().str().size() > 1024 * 1024)G_ERROR_MESSAGE().str(G_ERROR_MESSAGE().str().substr(512 * 1024));G_ERROR_MESSAGE() << strMsg << endl;}if (!m_bCache && m_filename.size() != 0){string newfile = makelogfilename();if (m_filename != newfile){m_ofs.close();_Open(newfile);cout << "文件切换，原文件 " << m_filename << " 新文件 " << newfile << endl;m_ofs << "文件切换，原文件 " << m_filename << " 新文件 " << newfile << endl;}m_ofs << strMsg.c_str() << endl;m_ofs.flush();if (m_ofs.bad()){m_ofs.close();_Open(newfile);cout << "写文件错误，关闭后重新打开文件" << endl;m_ofs << "写文件错误，关闭后重新打开文件" << endl;m_ofs << strMsg.c_str() << endl;m_ofs.flush();}}if (m_bOutput && ThreadSpec->m_bOutputThis){cout << strMsg.c_str() << endl;}else{if (m_bCache){if (m_cache.size() > m_maxcache){m_cache.erase(0, m_cache.size() / 2);//超长时删去前半部分}m_cache += strMsg + "\n";}}ThreadSpec->m_bOutputThis = true;if (m_pUD) (*m_pUD)(strMsg); // 用户定义功能ThreadSpec->m__file = "";ThreadSpec->m__line = 0;ThreadSpec->m_buf.str("");m_mutex.unlock();return *this;}Log& SetSource(const string& strSource){_getThreadSpec()->m_strSource = "[" + strSource + "]";return *this;}void setMaxFileSize(long){cout << "theLog.setMaxFileSize(maxsize) 此功能已取消" << endl;}void setCache(string::size_type maxcache){m_maxcache = maxcache;m_bCache = (maxcache > 0);}bool getCache()const { return m_bCache; }string & GetCachedLog(string & ret)//获得缓存的日志并清理缓存{ret = m_cache;m_cache.clear();return ret;}void ClearCache()//结束缓存，丢弃缓存的东西{m_cache.clear();setCache(0);}void setOutput(bool bEnable = true) { m_bOutput = bEnable; }bool getOutput() { return m_bOutput; }Log & setOutputThis(bool bEnable = false) { _getThreadSpec()->m_bOutputThis = bEnable; return *this; }
#ifdef _LINUXOSint _Open(const string& strFile, std::_Ios_Openmode nMode = ios::out | ios::app)
#elseint _Open(const string& strFile, int nMode = ios::out | ios::app)
#endif{m_ofs.close();m_ofs.clear();m_ofs.open(strFile.c_str(), nMode);if (!m_ofs.good()){cout << "打开文件出错 " << strFile << " " << strerror(errno) << endl;return -1;}m_filename = strFile;return 1;}//以固定文件方式打开日志，不会根据日期切换int Open(char const * filename){cout << "theLog.Open(filename) 此操作将取消按日期生成日志文件的功能，若要使用按日期分文件请取消此调用" << endl;m_appname_old = m_appname;m_appname = "";return _Open(filename);}int ReturnToOldFile(){return ActiveOpen(m_appname_old.c_str());}//根据当前年月日构造日志文件名，若未设置m_appname则为m_filenamestring makelogfilename(){if (0 == m_appname.size())return m_filename;time_t t;tm const * t2;char buf[256];time(&t);t2 = localtime(&t);sprintf(buf, "%s.%04d%02d%02d.log", m_appname.c_str(), t2->tm_year + 1900, t2->tm_mon + 1, t2->tm_mday);return buf;}//按日期打开日志，日期改变日志文件自动切换，格式为“appname.YYYYMMDD.log”int ActiveOpen(char const * appname){m_appname = appname;return _Open(makelogfilename());}//获得当前日志位置long tellEndP(){m_ofs.seekp(0, ios::end);return m_ofs.tellp();}//返回当前日志记录数long getCountN(){return countn;}long getCountW(){return countw;}long getCountE(){return counte;}};//日志接口
#define LOG (thelog)
#define ENDI (endi)
#define ENDW (endw)
#define ENDE (ende)

源文件：

    //这个好像没啥用，但是我暂时没验证，不敢删ostream & operator<<(ostream & s, LogEnd const & end){switch (end.end){case LogEnd::fENDI:s << "[信息]";break;case LogEnd::fENDW:s << "[警告]";break;case LogEnd::fENDE:s << "[出错]";break;case LogEnd::fENDF:s << "[致命]";break;case LogEnd::fENDD:s << "[调试]";break;}s << endl;return s;}string const & Log::_makesource(string const & source, string & ret){if (m_thread_count < 2)return source;_ThreadSpec * ThreadSpec = _getThreadSpec();char buf[256];if (0 == ThreadSpec->m_thread_id){sprintf(buf, "[%lu]", (unsigned long)getpid());}else{sprintf(buf, "[%lu-%2ld]", (unsigned long)getpid(), ThreadSpec->m_thread_id);}return ret = source + buf;}

代码里面用到了一个互斥对象，代码是这样的，简单包装而已：

	//线程同步对象class CPThreadMutex{private:pthread_mutex_t m_mutex;//互斥对象pthread_cond_t m_cond;//条件变量public:void init(){pthread_mutex_init(&m_mutex, NULL);pthread_cond_init(&m_cond, NULL);}void destory(){pthread_cond_destroy(&m_cond);pthread_mutex_destroy(&m_mutex);}int lock()const { return pthread_mutex_lock((pthread_mutex_t*)&m_mutex); }int unlock()const { return pthread_mutex_unlock((pthread_mutex_t*)&m_mutex); }int wait()const { return pthread_cond_wait((pthread_cond_t*)&m_cond, (pthread_mutex_t*)&m_mutex); }int reltimedwait()const{timespec to;to.tv_sec = time(NULL) + 1;to.tv_nsec = 0;int ret;ret = pthread_cond_timedwait((pthread_cond_t*)&m_cond, (pthread_mutex_t*)&m_mutex, &to);if (0 == ret)return true;else if (ETIMEDOUT == ret)return false;else throw ret;return false;}int signal()const { return pthread_cond_signal((pthread_cond_t*)&m_cond); }};

二、详解

2.1 关于endi、ende、endr

这一套是传统留下来的，在结束输出的时候表明这是什么性质的日志。含义很简单：

endi 信息

endd 调试

ende 出错

endr 报告——由于endr和某些版本的oracle客户端冲突，再说也没有实际使用，所以就删掉了

这个东西可以根据需要扩展。

2.2 多线程支持

由于日志对象是个全局对象，为了支持多线程使用，需要在内部实现多线程支持。具体办法是将临时缓存的数据放在线程存储里面。这里用的是POSIX线程库：

		//线程数据struct _ThreadSpec{long m_thread_id;stringstream m_buf;string m_strSource;bool m_bOutputThis;//仅控制当前一行输出string m__file;long m__line;string m__func;_ThreadSpec() :m_thread_id(0), m_bOutputThis(true), m__line(0) {}};static void _CloseThreadSpec(void * _p){_ThreadSpec * p=(_ThreadSpec *)_p;delete p;}_ThreadSpec * _getThreadSpec(){_ThreadSpec * p = (_ThreadSpec *)pthread_getspecific(tsd_key);if (p)return p;else{p = new _ThreadSpec;if (!p){throw "new _ThreadSpec return NULL";}m_mutex.lock();p->m_thread_id = m_thread_count;++m_thread_count;m_mutex.unlock();if (0 == pthread_setspecific(tsd_key, p)){return p;}else{throw "pthread_setspecific error";}}}

_getThreadSpec()用于获取线程数据，日志类的其他部分只用这个函数来操作数据。

为了保证输出文件不混乱，在输出的时候使用了互斥锁。