non/Timeline/Disk_Stream.H

/*******************************************************************************/
/* Copyright (C) 2008 Jonathan Moore Liles                                     */
/*                                                                             */
/* This program is free software; you can redistribute it and/or modify it     */
/* under the terms of the GNU General Public License as published by the       */
/* Free Software Foundation; either version 2 of the License, or (at your      */
/* option) any later version.                                                  */
/*                                                                             */
/* This program 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 along     */
/* with This program; see the file COPYING.  If not,write to the Free Software */
/* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
/*******************************************************************************/

#pragma once

#include "types.h"

#include <jack/ringbuffer.h>
#include <semaphore.h>
#include <errno.h>

#include <pthread.h>

#include "Mutex.H"

#include <vector>
using std::vector;

class Track;
class Audio_Sequence;

class Disk_Stream : public Mutex
{

protected:

    pthread_t _thread;                                 /* io thread */

    Track *_th;                               /* Track we belong to */

    nframes_t _nframes;                              /* buffer size */

    nframes_t _frame;                      /* location of disk read */

    vector < jack_ringbuffer_t * >_rb; /* one ringbuffer for each channel */

    sem_t _blocks;          /* semaphore to wake the IO thread with */

    int _total_blocks; /* total number of blocks that we can  buffer */
    int _disk_io_blocks; /* the number of blocks to read/write to/from disk at once */

    volatile nframes_t _pending_seek; /* absolute transport position to seek to */
    volatile int _terminate;

    int channels ( void ) const { return _rb.size(); }

    Audio_Sequence * track ( void );

    static void *disk_thread ( void *arg );

protected:

    void block_processed ( void ) { sem_post( &_blocks ); }
    bool wait_for_block ( void )
        {
            if ( _terminate )
                return false;
            else
            {
                while ( sem_wait( &_blocks ) == EINTR );
                return true;
            }
        }

    virtual void disk_thread ( void ) = 0;

public:

    /* must be set before any Disk_Streams are created */
    static float seconds_to_buffer;
    static size_t disk_io_kbytes;

    Disk_Stream ( Track *th, float frame_rate, nframes_t nframes, int channels );

    virtual ~Disk_Stream ( );

    void resize ( nframes_t nframes );

/*     void seek ( nframes_t frame ); */
/*     bool seek_pending ( void ); */

    void run ( void );
    void shutdown ( void );

    virtual nframes_t process ( nframes_t nframes ) = 0;

    int buffer_percent ( void );

};