code.delx.au - pulseaudio/blob - polyp/memchunk.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published
   8   by the Free Software Foundation; either version 2 of the License,
   9   or (at your option) any later version.
  10
  11   polypaudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with polypaudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <assert.h>
  29 #include <string.h>
  30
  31 #include "memchunk.h"
  32
  33 void pa_memchunk_make_writable(struct pa_memchunk *c) {
  34     struct pa_memblock *n;
  35     assert(c && c->memblock && c->memblock->ref >= 1);
  36
  37     if (c->memblock->ref == 1)
  38         return;
  39
  40     n = pa_memblock_new(c->length);
  41     assert(n);
  42     memcpy(n->data, c->memblock->data+c->index, c->length);
  43     pa_memblock_unref(c->memblock);
  44     c->memblock = n;
  45     c->index = 0;
  46 }
  47
  48
  49 struct pa_mcalign {
  50     size_t base;
  51     struct pa_memchunk chunk;
  52     uint8_t *buffer;
  53     size_t buffer_fill;
  54 };
  55
  56 struct pa_mcalign *pa_mcalign_new(size_t base) {
  57     struct pa_mcalign *m;
  58     assert(base);
  59
  60     m = malloc(sizeof(struct pa_mcalign));
  61     assert(m);
  62     m->base = base;
  63     m->chunk.memblock = NULL;
  64     m->chunk.length = m->chunk.index = 0;
  65     m->buffer = NULL;
  66     m->buffer_fill = 0;
  67     return m;
  68 }
  69
  70 void pa_mcalign_free(struct pa_mcalign *m) {
  71     assert(m);
  72
  73     free(m->buffer);
  74
  75     if (m->chunk.memblock)
  76         pa_memblock_unref(m->chunk.memblock);
  77
  78     free(m);
  79 }
  80
  81 void pa_mcalign_push(struct pa_mcalign *m, const struct pa_memchunk *c) {
  82     assert(m && c && !m->chunk.memblock && c->memblock && c->length);
  83
  84     m->chunk = *c;
  85     pa_memblock_ref(m->chunk.memblock);
  86 }
  87
  88 int pa_mcalign_pop(struct pa_mcalign *m, struct pa_memchunk *c) {
  89     assert(m && c && m->base > m->buffer_fill);
  90     int ret;
  91
  92     if (!m->chunk.memblock)
  93         return -1;
  94
  95     if (m->buffer_fill) {
  96         size_t l = m->base - m->buffer_fill;
  97         if (l > m->chunk.length)
  98             l = m->chunk.length;
  99         assert(m->buffer && l);
 100
 101         memcpy(m->buffer + m->buffer_fill, m->chunk.memblock->data + m->chunk.index, l);
 102         m->buffer_fill += l;
 103         m->chunk.index += l;
 104         m->chunk.length -= l;
 105
 106         if (m->chunk.length == 0) {
 107             m->chunk.length = m->chunk.index = 0;
 108             pa_memblock_unref(m->chunk.memblock);
 109             m->chunk.memblock = NULL;
 110         }
 111
 112         assert(m->buffer_fill <= m->base);
 113         if (m->buffer_fill == m->base) {
 114             c->memblock = pa_memblock_new_dynamic(m->buffer, m->base);
 115             assert(c->memblock);
 116             c->index = 0;
 117             c->length = m->base;
 118             m->buffer = NULL;
 119             m->buffer_fill = 0;
 120
 121             return 0;
 122         }
 123
 124         return -1;
 125     }
 126
 127     m->buffer_fill = m->chunk.length % m->base;
 128
 129     if (m->buffer_fill) {
 130         assert(!m->buffer);
 131         m->buffer = malloc(m->base);
 132         assert(m->buffer);
 133         m->chunk.length -= m->buffer_fill;
 134         memcpy(m->buffer, m->chunk.memblock->data + m->chunk.index + m->chunk.length, m->buffer_fill);
 135     }
 136
 137     if (m->chunk.length) {
 138         *c = m->chunk;
 139         pa_memblock_ref(c->memblock);
 140         ret = 0;
 141     } else
 142         ret = -1;
 143
 144     m->chunk.length = m->chunk.index = 0;
 145     pa_memblock_unref(m->chunk.memblock);
 146     m->chunk.memblock = NULL;
 147
 148     return ret;
 149 }