src/pulsecore/memchunk.h

   1 #ifndef foomemchunkhfoo
   2 #define foomemchunkhfoo
   3
   4 /***
   5   This file is part of PulseAudio.
   6
   7   Copyright 2004-2006 Lennart Poettering
   8
   9   PulseAudio is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU Lesser General Public License as
  11   published by the Free Software Foundation; either version 2.1 of the
  12   License, or (at your option) any later version.
  13
  14   PulseAudio is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public
  20   License along with PulseAudio; if not, write to the Free Software
  21   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  22   USA.
  23 ***/
  24
  25 #include <pulsecore/memblock.h>
  26
  27 /* A memchunk describes a part of a memblock. In contrast to the memblock, a
  28  * memchunk is not allocated dynamically or reference counted, instead
  29  * it is usually stored on the stack and copied around */
  30
  31 typedef struct pa_memchunk {
  32     pa_memblock *memblock;
  33     size_t index, length;
  34 } pa_memchunk;
  35
  36 /* Make a memchunk writable, i.e. make sure that the caller may have
  37  * exclusive access to the memblock and it is not read_only. If needed
  38  * the memblock in the structure is replaced by a copy. If min is not
  39  * 0 it is made sure that the returned memblock is at least of the
  40  * specified size, i.e. is enlarged if necessary. */
  41 pa_memchunk* pa_memchunk_make_writable(pa_memchunk *c, size_t min);
  42
  43 /* Invalidate a memchunk. This does not free the cotaining memblock,
  44  * but sets all members to zero. */
  45 pa_memchunk* pa_memchunk_reset(pa_memchunk *c);
  46
  47 /* Map a memory chunk back into memory if it was swapped out */
  48 pa_memchunk *pa_memchunk_will_need(const pa_memchunk *c);
  49
  50 /* Copy the data in the src memchunk to the dst memchunk */
  51 pa_memchunk* pa_memchunk_memcpy(pa_memchunk *dst, pa_memchunk *src);
  52
  53 /* Return TRUE if any field is set != 0 */
  54 pa_bool_t pa_memchunk_isset(pa_memchunk *c);
  55
  56 #endif