4 This file is part of PulseAudio.
6 Copyright 2004-2006 Lennart Poettering
8 PulseAudio is free software; you can redistribute it and/or modify
9 it under the terms of the GNU Lesser General Public License as
10 published by the Free Software Foundation; either version 2.1 of the
11 License, or (at your option) any later version.
13 PulseAudio is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public
19 License along with PulseAudio; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
33 #include <pulse/xmalloc.h>
39 pa_memchunk leftover, current;
42 pa_mcalign *pa_mcalign_new(size_t base) {
46 m = pa_xnew(pa_mcalign, 1);
49 pa_memchunk_reset(&m->leftover);
50 pa_memchunk_reset(&m->current);
55 void pa_mcalign_free(pa_mcalign *m) {
58 if (m->leftover.memblock)
59 pa_memblock_unref(m->leftover.memblock);
61 if (m->current.memblock)
62 pa_memblock_unref(m->current.memblock);
67 void pa_mcalign_push(pa_mcalign *m, const pa_memchunk *c) {
72 assert(c->length > 0);
74 assert(!m->current.memblock);
76 /* Append to the leftover memory block */
77 if (m->leftover.memblock) {
80 if (m->leftover.memblock == c->memblock &&
81 m->leftover.index + m->leftover.length == c->index) {
84 m->leftover.length += c->length;
86 /* If the new chunk is larger than m->base, move it to current */
87 if (m->leftover.length >= m->base) {
88 m->current = m->leftover;
89 pa_memchunk_reset(&m->leftover);
96 assert(m->leftover.length < m->base);
97 l = m->base - m->leftover.length;
102 /* Can we use the current block? */
103 pa_memchunk_make_writable(&m->leftover, m->base);
105 memcpy((uint8_t*) m->leftover.memblock->data + m->leftover.index + m->leftover.length, (uint8_t*) c->memblock->data + c->index, l);
106 m->leftover.length += l;
108 assert(m->leftover.length <= m->base && m->leftover.length <= m->leftover.memblock->length);
111 /* Save the remainder of the memory block */
113 m->current.index += l;
114 m->current.length -= l;
115 pa_memblock_ref(m->current.memblock);
119 /* Nothing to merge or copy, just store it */
121 if (c->length >= m->base)
126 pa_memblock_ref(c->memblock);
130 int pa_mcalign_pop(pa_mcalign *m, pa_memchunk *c) {
134 /* First test if there's a leftover memory block available */
135 if (m->leftover.memblock) {
136 assert(m->leftover.length > 0 && m->leftover.length <= m->base);
138 /* The leftover memory block is not yet complete */
139 if (m->leftover.length < m->base)
142 /* Return the leftover memory block */
144 pa_memchunk_reset(&m->leftover);
146 /* If the current memblock is too small move it the leftover */
147 if (m->current.memblock && m->current.length < m->base) {
148 m->leftover = m->current;
149 pa_memchunk_reset(&m->current);
155 /* Now let's see if there is other data available */
156 if (m->current.memblock) {
158 assert(m->current.length >= m->base);
160 /* The length of the returned memory block */
161 l = m->current.length;
166 /* Prepare the returned block */
168 pa_memblock_ref(c->memblock);
171 /* Drop that from the current memory block */
172 assert(l <= m->current.length);
173 m->current.index += l;
174 m->current.length -= l;
176 /* In case the whole block was dropped ... */
177 if (m->current.length == 0)
178 pa_memblock_unref(m->current.memblock);
180 /* Move the raimainder to leftover */
181 assert(m->current.length < m->base && !m->leftover.memblock);
183 m->leftover = m->current;
186 pa_memchunk_reset(&m->current);
191 /* There's simply nothing */
196 size_t pa_mcalign_csize(pa_mcalign *m, size_t l) {
200 assert(!m->current.memblock);
202 if (m->leftover.memblock)
203 l += m->leftover.length;
205 return (l/m->base)*m->base;