src/buffer.h

   1 /*
   2  * Copyright (C) 2003-2010 The Music Player Daemon Project
   3  * http://www.musicpd.org
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #ifndef MPD_MUSIC_BUFFER_H
  21 #define MPD_MUSIC_BUFFER_H
  22
  23 /**
  24  * An allocator for #music_chunk objects.
  25  */
  26 struct music_buffer;
  27
  28 /**
  29  * Creates a new #music_buffer object.
  30  *
  31  * @param num_chunks the number of #music_chunk reserved in this
  32  * buffer
  33  */
  34 struct music_buffer *
  35 music_buffer_new(unsigned num_chunks);
  36
  37 /**
  38  * Frees the #music_buffer object
  39  */
  40 void
  41 music_buffer_free(struct music_buffer *buffer);
  42
  43 /**
  44  * Returns the total number of reserved chunks in this buffer.  This
  45  * is the same value which was passed to the constructor
  46  * music_buffer_new().
  47  */
  48 unsigned
  49 music_buffer_size(const struct music_buffer *buffer);
  50
  51 /**
  52  * Allocates a chunk from the buffer.  When it is not used anymore,
  53  * call music_buffer_return().
  54  *
  55  * @return an empty chunk or NULL if there are no chunks available
  56  */
  57 struct music_chunk *
  58 music_buffer_allocate(struct music_buffer *buffer);
  59
  60 /**
  61  * Returns a chunk to the buffer.  It can be reused by
  62  * music_buffer_allocate() then.
  63  */
  64 void
  65 music_buffer_return(struct music_buffer *buffer, struct music_chunk *chunk);
  66
  67 #endif