/*MT*
    
    MediaTomb - http://www.mediatomb.cc/
    
    io_handler_buffer_helper.h - this file is part of MediaTomb.
    
    Copyright (C) 2005 Gena Batyan <bgeradz@mediatomb.cc>,
                       Sergey 'Jin' Bostandzhyan <jin@mediatomb.cc>
    
    Copyright (C) 2006-2010 Gena Batyan <bgeradz@mediatomb.cc>,
                            Sergey 'Jin' Bostandzhyan <jin@mediatomb.cc>,
                            Leonhard Wimmer <leo@mediatomb.cc>
    
    MediaTomb is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License version 2
    as published by the Free Software Foundation.
    
    MediaTomb 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 General Public License for more details.
    
    You should have received a copy of the GNU General Public License
    version 2 along with MediaTomb; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
    
    $Id$
*/

/// \file io_handler_buffer_helper.h

#ifndef __IO_HANDLER_BUFFER_HELPER_H__
#define __IO_HANDLER_BUFFER_HELPER_H__

#include <pthread.h>
#include <upnp.h>
#include <mutex>
#include <condition_variable>

#include "common.h"
#include "io_handler.h"

/// \brief a IOHandler with buffer support
/// the buffer is only for read(). write() is not supported
/// the public functions of this class are *not* thread safe!
class IOHandlerBufferHelper : public IOHandler
{
public:
    
    /// \brief get an instance of a IOHandlerBufferHelper
    /// \param bufSize the size of the buffer in bytes
    /// \param maxChunkSize the maximum size of the chunks which are read by the buffer
    /// \param initialFillSize the number of bytes which have to be in the buffer
    /// before the first read at the very beginning or after a seek returns;
    /// 0 disables the delay
    IOHandlerBufferHelper(size_t bufSize, size_t initialFillSize);
    virtual ~IOHandlerBufferHelper();
    
    // inherited from IOHandler
    virtual void open(enum UpnpOpenFileMode mode);
    virtual int read(char *buf, size_t length);
    virtual void seek(off_t offset, int whence);
    virtual void close();
    
protected:
    size_t bufSize;
    size_t initialFillSize;
    char* buffer;
    bool isOpen;
    bool eof;
    bool readError;
    bool waitForInitialFillSize;
    bool signalAfterEveryRead;
    bool checkSocket;
    
    // buffer stuff..
    bool empty;
    size_t a;
    size_t b;
    off_t posRead;
    
    // seek stuff...
    bool seekEnabled;
    bool doSeek;
    off_t seekOffset;
    int seekWhence;
    
    // thread stuff..
    void startBufferThread();
    void stopBufferThread();
    static void *staticThreadProc(void *arg);
    virtual void threadProc() = 0;
    
    pthread_t bufferThread;
    bool threadShutdown;

    std::condition_variable cond;
    std::mutex mutex;
};

#endif // __IO_HANDLER_BUFFER_HELPER_H__
