logger.h

00001 /***********************************************************************
00002  * Software License Agreement (BSD License)
00003  *
00004  * Copyright 2008-2009  Marius Muja (mariusm@cs.ubc.ca). All rights reserved.
00005  * Copyright 2008-2009  David G. Lowe (lowe@cs.ubc.ca). All rights reserved.
00006  *
00007  * THE BSD LICENSE
00008  *
00009  * Redistribution and use in source and binary forms, with or without
00010  * modification, are permitted provided that the following conditions
00011  * are met:
00012  *
00013  * 1. Redistributions of source code must retain the above copyright
00014  *    notice, this list of conditions and the following disclaimer.
00015  * 2. Redistributions in binary form must reproduce the above copyright
00016  *    notice, this list of conditions and the following disclaimer in the
00017  *    documentation and/or other materials provided with the distribution.
00018  *
00019  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
00020  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00021  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
00022  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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00024  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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00028  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00029  *************************************************************************/
00030 
00031 #ifndef OPENCV_FLANN_LOGGER_H
00032 #define OPENCV_FLANN_LOGGER_H
00033 
00034 #include <stdio.h>
00035 #include <stdarg.h>
00036 
00037 #include "defines.h"
00038 
00039 
00040 namespace cvflann
00041 {
00042 
00043 class Logger
00044 {
00045     Logger() : stream(stdout), logLevel(FLANN_LOG_WARN) {}
00046 
00047     ~Logger()
00048     {
00049         if ((stream!=NULL)&&(stream!=stdout)) {
00050             fclose(stream);
00051         }
00052     }
00053 
00054     static Logger& instance()
00055     {
00056         static Logger logger;
00057         return logger;
00058     }
00059 
00060     void _setDestination(const char* name)
00061     {
00062         if (name==NULL) {
00063             stream = stdout;
00064         }
00065         else {
00066             stream = fopen(name,"w");
00067             if (stream == NULL) {
00068                 stream = stdout;
00069             }
00070         }
00071     }
00072 
00073     int _log(int level, const char* fmt, va_list arglist)
00074     {
00075         if (level > logLevel ) return -1;
00076         int ret = vfprintf(stream, fmt, arglist);
00077         return ret;
00078     }
00079 
00080 public:
00081     /**
00082      * Sets the logging level. All messages with lower priority will be ignored.
00083      * @param level Logging level
00084      */
00085     static void setLevel(int level) { instance().logLevel = level; }
00086 
00087     /**
00088      * Sets the logging destination
00089      * @param name Filename or NULL for console
00090      */
00091     static void setDestination(const char* name) { instance()._setDestination(name); }
00092 
00093     /**
00094      * Print log message
00095      * @param level Log level
00096      * @param fmt Message format
00097      * @return
00098      */
00099     static int log(int level, const char* fmt, ...)
00100     {
00101         va_list arglist;
00102         va_start(arglist, fmt);
00103         int ret = instance()._log(level,fmt,arglist);
00104         va_end(arglist);
00105         return ret;
00106     }
00107 
00108 #define LOG_METHOD(NAME,LEVEL) \
00109     static int NAME(const char* fmt, ...) \
00110     { \
00111         va_list ap; \
00112         va_start(ap, fmt); \
00113         int ret = instance()._log(LEVEL, fmt, ap); \
00114         va_end(ap); \
00115         return ret; \
00116     }
00117 
00118     LOG_METHOD(fatal, FLANN_LOG_FATAL)
00119     LOG_METHOD(error, FLANN_LOG_ERROR)
00120     LOG_METHOD(warn, FLANN_LOG_WARN)
00121     LOG_METHOD(info, FLANN_LOG_INFO)
00122 
00123 private:
00124     FILE* stream;
00125     int logLevel;
00126 };
00127 
00128 }
00129 
00130 #endif //OPENCV_FLANN_LOGGER_H
00131