/*****************************************************************************

 * fifo.c: FIFO management functions

 *****************************************************************************

 * Copyright (C) 2003-2004 VLC authors and VideoLAN

 * Copyright (C) 2007-2015 Rémi Denis-Courmont

 *

 * Authors: Laurent Aimar <fenrir@videolan.org>

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU Lesser General Public License as published by

 * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.

 *****************************************************************************/

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#include <assert.h>

#include <stdlib.h>

#include <vlc_common.h>

#include <vlc_block.h>

#include "../libvlc.h"

/**

 * Internal state for block queues

 */

struct vlc_fifo_t

{

    vlc_queue_t         q;

    size_t              i_depth;

    size_t              i_size;

};

static_assert (offsetof (block_fifo_t, q) == 0, "Problems in <vlc_block.h>");

bool vlc_fifo_Held(const block_fifo_t *fifo)

{

    return vlc_mutex_held(&fifo->q.lock);

}

size_t vlc_fifo_GetCount(const block_fifo_t *fifo)

{

    vlc_mutex_assert(&fifo->q.lock);

    return fifo->i_depth;

}

size_t vlc_fifo_GetBytes(const block_fifo_t *fifo)

{

    vlc_mutex_assert(&fifo->q.lock);

    return fifo->i_size;

}

void vlc_fifo_QueueUnlocked(block_fifo_t *fifo, block_t *block)

{

    for (block_t *b = block; b != NULL; b = b->p_next) {

        fifo->i_depth++;

        fifo->i_size += b->i_buffer;

    }

    vlc_queue_EnqueueUnlocked(&fifo->q, block);

}

block_t *vlc_fifo_DequeueUnlocked(block_fifo_t *fifo)

{

    block_t *block = vlc_queue_DequeueUnlocked(&fifo->q);

    if (block != NULL) {

        assert(fifo->i_depth > 0);

        assert(fifo->i_size >= block->i_buffer);

        fifo->i_depth--;

        fifo->i_size -= block->i_buffer;

    }

    return block;

}

block_t *vlc_fifo_DequeueAllUnlocked(block_fifo_t *fifo)

{

    fifo->i_depth = 0;

    fifo->i_size = 0;

    return vlc_queue_DequeueAllUnlocked(&fifo->q);

}

block_fifo_t *vlc_fifo_New( void )

{

    block_fifo_t *p_fifo = malloc( sizeof( block_fifo_t ) );

    if (likely(p_fifo != NULL)) {

        vlc_queue_Init(&p_fifo->q, offsetof (block_t, p_next));

        p_fifo->i_depth = 0;

        p_fifo->i_size = 0;

    }

    return p_fifo;

}

void vlc_fifo_Delete( block_fifo_t *p_fifo )

{

    vlc_fifo_Empty(p_fifo);

    free( p_fifo );

}

block_t *vlc_fifo_Get(block_fifo_t *fifo)

{

    block_t *block;

    vlc_testcancel();

    vlc_fifo_Lock(fifo);

    while (vlc_fifo_IsEmpty(fifo))

    {

        vlc_fifo_CleanupPush(fifo);

        vlc_fifo_Wait(fifo);

        vlc_cleanup_pop();

    }

    block = vlc_fifo_DequeueUnlocked(fifo);

    vlc_fifo_Unlock(fifo);

    return block;

}

block_t *vlc_fifo_Show( block_fifo_t *p_fifo )

{

    block_t *b;

    vlc_fifo_Lock(p_fifo);

    assert(p_fifo->q.first != NULL);

    b = (block_t *)p_fifo->q.first;

    vlc_fifo_Unlock(p_fifo);

    return b;

}