juce/source/src/core/juce_FileLogger.h

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library - "Jules' Utility Class Extensions"
   5    Copyright 2004-11 by Raw Material Software Ltd.
   6
   7   ------------------------------------------------------------------------------
   8
   9    JUCE can be redistributed and/or modified under the terms of the GNU General
  10    Public License (Version 2), as published by the Free Software Foundation.
  11    A copy of the license is included in the JUCE distribution, or can be found
  12    online at www.gnu.org/licenses.
  13
  14    JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
  15    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  16    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  17
  18   ------------------------------------------------------------------------------
  19
  20    To release a closed-source product which uses JUCE, commercial licenses are
  21    available: visit www.rawmaterialsoftware.com/juce for more information.
  22
  23   ==============================================================================
  24 */
  25
  26 #ifndef __JUCE_FILELOGGER_JUCEHEADER__
  27 #define __JUCE_FILELOGGER_JUCEHEADER__
  28
  29 #include "juce_Logger.h"
  30 #include "../io/files/juce_File.h"
  31 #include "../memory/juce_ScopedPointer.h"
  32
  33
  34 //==============================================================================
  35 /**
  36     A simple implemenation of a Logger that writes to a file.
  37
  38     @see Logger
  39 */
  40 class JUCE_API  FileLogger  : public Logger
  41 {
  42 public:
  43     //==============================================================================
  44     /** Creates a FileLogger for a given file.
  45
  46         @param fileToWriteTo    the file that to use - new messages will be appended
  47                                 to the file. If the file doesn't exist, it will be created,
  48                                 along with any parent directories that are needed.
  49         @param welcomeMessage   when opened, the logger will write a header to the log, along
  50                                 with the current date and time, and this welcome message
  51         @param maxInitialFileSizeBytes  if this is zero or greater, then if the file already exists
  52                                 but is larger than this number of bytes, then the start of the
  53                                 file will be truncated to keep the size down. This prevents a log
  54                                 file getting ridiculously large over time. The file will be truncated
  55                                 at a new-line boundary. If this value is less than zero, no size limit
  56                                 will be imposed; if it's zero, the file will always be deleted. Note that
  57                                 the size is only checked once when this object is created - any logging
  58                                 that is done later will be appended without any checking
  59     */
  60     FileLogger (const File& fileToWriteTo,
  61                 const String& welcomeMessage,
  62                 const int maxInitialFileSizeBytes = 128 * 1024);
  63
  64     /** Destructor. */
  65     ~FileLogger();
  66
  67     //==============================================================================
  68     void logMessage (const String& message);
  69
  70     File getLogFile() const               { return logFile; }
  71
  72     //==============================================================================
  73     /** Helper function to create a log file in the correct place for this platform.
  74
  75         On Windows this will return a logger with a path such as:
  76         c:\\Documents and Settings\\username\\Application Data\\[logFileSubDirectoryName]\\[logFileName]
  77
  78         On the Mac it'll create something like:
  79         ~/Library/Logs/[logFileName]
  80
  81         The method might return 0 if the file can't be created for some reason.
  82
  83         @param logFileSubDirectoryName      if a subdirectory is needed, this is what it will be called -
  84                                             it's best to use the something like the name of your application here.
  85         @param logFileName                  the name of the file to create, e.g. "MyAppLog.txt". Don't just
  86                                             call it "log.txt" because if it goes in a directory with logs
  87                                             from other applications (as it will do on the Mac) then no-one
  88                                             will know which one is yours!
  89         @param welcomeMessage               a message that will be written to the log when it's opened.
  90         @param maxInitialFileSizeBytes      (see the FileLogger constructor for more info on this)
  91     */
  92     static FileLogger* createDefaultAppLogger (const String& logFileSubDirectoryName,
  93                                                const String& logFileName,
  94                                                const String& welcomeMessage,
  95                                                const int maxInitialFileSizeBytes = 128 * 1024);
  96
  97 private:
  98     //==============================================================================
  99     File logFile;
 100     CriticalSection logLock;
 101
 102     void trimFileSize (int maxFileSizeBytes) const;
 103
 104     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (FileLogger);
 105 };
 106
 107
 108 #endif   // __JUCE_FILELOGGER_JUCEHEADER__