apps/gui/skin_engine/skin_buffer.h

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2002 by Linus Nielsen Feltzing
  11  * Copyright (C) 2009 Jonathan Gordon
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License
  15  * as published by the Free Software Foundation; either version 2
  16  * of the License, or (at your option) any later version.
  17  *
  18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19  * KIND, either express or implied.
  20  *
  21  ****************************************************************************/
  22
  23 #ifndef _SKIN_BUFFER_H_
  24 #define _SKIN_BUFFER_H_
  25
  26
  27 #include <stdio.h>
  28 #include <string.h>
  29 #include <stdlib.h>
  30
  31 /* int the global buffer */
  32 void skin_buffer_init(void);
  33
  34 /* get the number of bytes currently being used */
  35 size_t skin_buffer_usage(void);
  36 size_t skin_buffer_freespace(void);
  37
  38 /* Allocate size bytes from the buffer */
  39 void* skin_buffer_alloc(size_t size);
  40
  41
  42 /* Get a pointer to the skin buffer and the count of how much is free
  43  * used to do your own buffer management.
  44  * Any memory used will be overwritten next time wps_buffer_alloc()
  45  * is called unless skin_buffer_increment() is called first
  46  *
  47  * This is from the start of the buffer, it is YOUR responsility to make
  48  * sure you dont ever use more then *freespace, and bear in mind this will only
  49  * be valid untill skin_buffer_alloc() is next called...
  50  * so call skin_buffer_increment() and skin_buffer_freespace() regularly
  51  */
  52 void* skin_buffer_grab(size_t *freespace);
  53
  54 /* Use after skin_buffer_grab() to specify how much buffer was used.
  55  * align should always be true unless there is a possibility that you will need
  56  * more space *immediatly* after the previous allocation. (i.e in an array).
  57  * NEVER leave the buffer unaligned */
  58 void skin_buffer_increment(size_t used, bool align);
  59
  60 /* free previously skin_buffer_increment()'ed space. This just moves the pointer
  61  * back 'used' bytes so make sure you actually want to do this */
  62 void skin_buffer_free_from_front(size_t used);
  63
  64 #endif /* _SKIN_BUFFER_H_ */