/*

  * This file is part of FFmpeg.

  *

  * FFmpeg 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.
  *

  * FFmpeg 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 FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #ifndef AVUTIL_BUFFER_INTERNAL_H
 #define AVUTIL_BUFFER_INTERNAL_H
 
 #include <stdint.h>
 
 #include "buffer.h"

 #include "thread.h"

 
 /**
  * The buffer is always treated as read-only.
  */
 #define BUFFER_FLAG_READONLY      (1 << 0)
 /**
  * The buffer was av_realloc()ed, so it is reallocatable.
  */
 #define BUFFER_FLAG_REALLOCATABLE (1 << 1)
 
 struct AVBuffer {
     uint8_t *data; /**< data described by this buffer */
     int      size; /**< size of data in bytes */
 
     /**
      *  number of existing AVBufferRef instances referring to this buffer
      */
     volatile int refcount;
 
     /**
      * a callback for freeing the data
      */
     void (*free)(void *opaque, uint8_t *data);
 
     /**
      * an opaque pointer, to be used by the freeing callback
      */
     void *opaque;
 
     /**
      * A combination of BUFFER_FLAG_*
      */
     int flags;
 };
 

 typedef struct BufferPoolEntry {
     uint8_t *data;
 
     /*
      * Backups of the original opaque/free of the AVBuffer corresponding to
      * data. They will be used to free the buffer when the pool is freed.
      */
     void *opaque;
     void (*free)(void *opaque, uint8_t *data);
 
     AVBufferPool *pool;

     struct BufferPoolEntry * volatile next;

 } BufferPoolEntry;
 
 struct AVBufferPool {

     AVMutex mutex;

     BufferPoolEntry * volatile pool;

 
     /*
      * This is used to track when the pool is to be freed.
      * The pointer to the pool itself held by the caller is considered to
      * be one reference. Each buffer requested by the caller increases refcount
      * by one, returning the buffer to the pool decreases it by one.
      * refcount reaches zero when the buffer has been uninited AND all the
      * buffers have been released, then it's safe to free the pool and all
      * the buffers in it.
      */
     volatile int refcount;
 

     volatile int nb_allocated;
 

     int size;
     AVBufferRef* (*alloc)(int size);
 };
 

 #endif /* AVUTIL_BUFFER_INTERNAL_H */