log.h

/* Copyright (C) 2014-2019 J.F.Dockes
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation; either version 2.1 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the
 *  Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#ifndef _LOG_H_X_INCLUDED_
#define _LOG_H_X_INCLUDED_
 
#include <string.h>  // for strerror
#include <fstream> 
#include <iostream>
#include <string>
 
#ifndef LOGGER_THREADSAFE
#define LOGGER_THREADSAFE 1
#endif
 
#if LOGGER_THREADSAFE
#include <mutex>
#endif
 
// Can't use the symbolic Logger::LLXX names in preproc. 6 is LLDEB1
// STATICVERBOSITY is the level above which logging statements are
// preproc'ed out (can't be dynamically turned on).
#ifndef LOGGER_STATICVERBOSITY
#define LOGGER_STATICVERBOSITY 5
#endif
 
#define LOGGER_DATESIZE 100
 
class Logger {
public:
    Logger(const Logger&) = delete;
    Logger& operator=(const Logger&) = delete;
 
    static Logger *getTheLog(const std::string& fn = std::string());
    static void cleanup();
 
    bool reopen(const std::string& fn);
 
    std::ostream& getstream() {
        return m_tocerr ? std::cerr : m_stream;
    }
 
    enum LogLevel {LLNON=0, LLFAT=1, LLERR=2, LLINF=3, LLDEB=4,
                   LLDEB0=5, LLDEB1=6, LLDEB2=7};
 
    void setLogLevel(LogLevel level) {
        m_loglevel = level;
    }
    void setloglevel(LogLevel level) {
        m_loglevel = level;
    }
 
    int getloglevel() const {
        return m_loglevel;
    }
    const std::string& getlogfilename() const {
        return m_fn;
    }
    bool logisstderr() const {
        return m_tocerr;
    }
 
    void logthedate(bool onoff) {
        m_logdate = onoff;
    }
 
    bool loggingdate() const {
        return m_logdate;
    }
    
    void setdateformat(const std::string fmt) {
        m_datefmt = fmt;
    }
 
    const char *datestring();
    
#if LOGGER_THREADSAFE
    std::recursive_mutex& getmutex() {
        return m_mutex;
    }
#endif
    
private:
    bool m_tocerr{false};
    bool m_logdate{false};
    int m_loglevel{LLERR};
    std::string m_datefmt{"%Y%m%d-%H%M%S"};
    std::string m_fn;
    std::ofstream m_stream;
#if LOGGER_THREADSAFE
    std::recursive_mutex m_mutex;
#endif
    char m_datebuf[LOGGER_DATESIZE];
    Logger(const std::string& fn);
    ~Logger();
};
 
#define LOGGER_PRT (Logger::getTheLog()->getstream())
 
#if LOGGER_THREADSAFE
#define LOGGER_LOCK                                                     \
    std::unique_lock<std::recursive_mutex> lock(Logger::getTheLog()->getmutex())
#else
#define LOGGER_LOCK
#endif
 
#ifndef LOGGER_LOCAL_LOGINC
#define LOGGER_LOCAL_LOGINC 0
#endif
 
#define LOGGER_LEVEL (Logger::getTheLog()->getloglevel() +    \
                      LOGGER_LOCAL_LOGINC)
 
#define LOGGER_DATE (Logger::getTheLog()->loggingdate() ? \
                     Logger::getTheLog()->datestring() : "")
 
#define LOGGER_DOLOG(L,X) LOGGER_PRT << LOGGER_DATE << ":" << L << ":" << \
                             __FILE__ << ":" << __LINE__ << "::" << X \
    << std::flush
 
 
#if LOGGER_STATICVERBOSITY >= 7
#define LOGDEB2(X) {                            \
        if (LOGGER_LEVEL >= Logger::LLDEB2) {   \
            LOGGER_LOCK;                        \
            LOGGER_DOLOG(Logger::LLDEB2, X);    \
        }                                       \
    }
#else
#define LOGDEB2(X)
#endif
 
#if LOGGER_STATICVERBOSITY >= 6
#define LOGDEB1(X) {                            \
        if (LOGGER_LEVEL >= Logger::LLDEB1) {   \
            LOGGER_LOCK;                        \
            LOGGER_DOLOG(Logger::LLDEB1, X);    \
        }                                       \
    }
#else
#define LOGDEB1(X)
#endif
 
#if LOGGER_STATICVERBOSITY >= 5
#define LOGDEB0(X) {                            \
        if (LOGGER_LEVEL >= Logger::LLDEB0) {   \
            LOGGER_LOCK;                        \
            LOGGER_DOLOG(Logger::LLDEB0, X);    \
        }                                       \
    }
#else
#define LOGDEB0(X)
#endif
 
#if LOGGER_STATICVERBOSITY >= 4
#define LOGDEB(X) {                             \
        if (LOGGER_LEVEL >= Logger::LLDEB) {    \
            LOGGER_LOCK;                        \
            LOGGER_DOLOG(Logger::LLDEB, X);     \
        }                                       \
    }
#else
#define LOGDEB(X)
#endif
 
#if LOGGER_STATICVERBOSITY >= 3
#define LOGINF(X) {                             \
        if (LOGGER_LEVEL >= Logger::LLINF) {    \
            LOGGER_LOCK;                        \
            LOGGER_DOLOG(Logger::LLINF, X);     \
        }                                       \
    }
#else
#define LOGINF(X)
#endif
#define LOGINFO LOGINF
 
#if LOGGER_STATICVERBOSITY >= 2
#define LOGERR(X) {                             \
        if (LOGGER_LEVEL >= Logger::LLERR) {    \
            LOGGER_LOCK;                        \
            LOGGER_DOLOG(Logger::LLERR, X);     \
        }                                       \
    }
#else
#define LOGERR(X)
#endif
 
#if LOGGER_STATICVERBOSITY >= 1
#define LOGFAT(X) {                             \
        if (LOGGER_LEVEL >= Logger::LLFAT) {    \
            LOGGER_LOCK;                        \
            LOGGER_DOLOG(Logger::LLFAT, X);     \
        }                                       \
    }
#else
#define LOGFAT(X)
#endif
#define LOGFATAL LOGFAT
 
#if defined(sun) || defined(_WIN32)
#define LOGSYSERR(who, what, arg) {                                     \
        LOGERR(who << ": " << what << "("  << arg << "): errno " << errno << \
               ": " << strerror(errno) << '\n');                        \
    }
#else // not WINDOWS or sun
 
inline char *_log_check_strerror_r(int, char *errbuf) {return errbuf;}
inline char *_log_check_strerror_r(char *cp, char *){return cp;}
 
#define LOGSYSERR(who, what, arg) {                                     \
        char buf[200]; buf[0] = 0;                                      \
        LOGERR(who << ": " << what << "("  << arg << "): errno " << errno << ": " << \
               _log_check_strerror_r(strerror_r(errno, buf, 200), buf) << '\n'); \
    }
 
#endif // not windows
 
#endif /* _LOG_H_X_INCLUDED_ */