JUCE/modules/juce_core/logging/juce_FileLogger.cpp

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2016 - ROLI Ltd.

   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.

   -----------------------------------------------------------------------------

   To release a closed-source product which uses other parts of JUCE not
   licensed under the ISC terms, commercial licenses are available: visit
   www.juce.com for more information.

  ==============================================================================
*/

FileLogger::FileLogger (const File& file,
                        const String& welcomeMessage,
                        const int64 maxInitialFileSizeBytes)
    : logFile (file)
{
    if (maxInitialFileSizeBytes >= 0)
        trimFileSize (logFile, maxInitialFileSizeBytes);

    if (! file.exists())
        file.create();  // (to create the parent directories)

    String welcome;
    welcome << newLine
            << "**********************************************************" << newLine
            << welcomeMessage << newLine
            << "Log started: " << Time::getCurrentTime().toString (true, true) << newLine;

    FileLogger::logMessage (welcome);
}

FileLogger::~FileLogger() {}

//==============================================================================
void FileLogger::logMessage (const String& message)
{
    const ScopedLock sl (logLock);
    DBG (message);
    FileOutputStream out (logFile, 256);
    out << message << newLine;
}

void FileLogger::trimFileSize (const File& file, int64 maxFileSizeBytes)
{
    if (maxFileSizeBytes <= 0)
    {
        file.deleteFile();
    }
    else
    {
        const int64 fileSize = file.getSize();

        if (fileSize > maxFileSizeBytes)
        {
            TemporaryFile tempFile (file);

            {
                FileOutputStream out (tempFile.getFile());
                FileInputStream in (file);

                if (! (out.openedOk() && in.openedOk()))
                    return;

                in.setPosition (fileSize - maxFileSizeBytes);

                for (;;)
                {
                    const char c = in.readByte();
                    if (c == 0)
                        return;

                    if (c == '\n' || c == '\r')
                    {
                        out << c;
                        break;
                    }
                }

                out.writeFromInputStream (in, -1);
            }

            tempFile.overwriteTargetFileWithTemporary();
        }
    }
}

//==============================================================================
File FileLogger::getSystemLogFileFolder()
{
   #if JUCE_MAC
    return File ("~/Library/Logs");
   #else
    return File::getSpecialLocation (File::userApplicationDataDirectory);
   #endif
}

FileLogger* FileLogger::createDefaultAppLogger (const String& logFileSubDirectoryName,
                                                const String& logFileName,
                                                const String& welcomeMessage,
                                                const int64 maxInitialFileSizeBytes)
{
    return new FileLogger (getSystemLogFileFolder().getChildFile (logFileSubDirectoryName)
                                                   .getChildFile (logFileName),
                           welcomeMessage, maxInitialFileSizeBytes);
}

FileLogger* FileLogger::createDateStampedLogger (const String& logFileSubDirectoryName,
                                                 const String& logFileNameRoot,
                                                 const String& logFileNameSuffix,
                                                 const String& welcomeMessage)
{
    return new FileLogger (getSystemLogFileFolder().getChildFile (logFileSubDirectoryName)
                                                   .getChildFile (logFileNameRoot + Time::getCurrentTime().formatted ("%Y-%m-%d_%H-%M-%S"))
                                                   .withFileExtension (logFileNameSuffix)
                                                   .getNonexistentSibling(),
                           welcomeMessage, 0);
}