JUCE/modules/juce_core/logging/juce_FileLogger.cpp

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

   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited

   JUCE is an open source library subject to commercial or open-source
   licensing.

   The code included in this file is provided 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.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

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

namespace juce
{

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);
}

} // namespace juce