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-rw-r--r--src/pulsecore/mcalign.c206
1 files changed, 206 insertions, 0 deletions
diff --git a/src/pulsecore/mcalign.c b/src/pulsecore/mcalign.c
new file mode 100644
index 00000000..8283a7a0
--- /dev/null
+++ b/src/pulsecore/mcalign.c
@@ -0,0 +1,206 @@
+/* $Id$ */
+
+/***
+ This file is part of PulseAudio.
+
+ PulseAudio is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ PulseAudio is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with PulseAudio; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+
+#include <pulse/xmalloc.h>
+
+#include "mcalign.h"
+
+struct pa_mcalign {
+ size_t base;
+ pa_memchunk leftover, current;
+ pa_memblock_stat *memblock_stat;
+};
+
+pa_mcalign *pa_mcalign_new(size_t base, pa_memblock_stat *s) {
+ pa_mcalign *m;
+ assert(base);
+
+ m = pa_xnew(pa_mcalign, 1);
+
+ m->base = base;
+ pa_memchunk_reset(&m->leftover);
+ pa_memchunk_reset(&m->current);
+ m->memblock_stat = s;
+
+ return m;
+}
+
+void pa_mcalign_free(pa_mcalign *m) {
+ assert(m);
+
+ if (m->leftover.memblock)
+ pa_memblock_unref(m->leftover.memblock);
+
+ if (m->current.memblock)
+ pa_memblock_unref(m->current.memblock);
+
+ pa_xfree(m);
+}
+
+void pa_mcalign_push(pa_mcalign *m, const pa_memchunk *c) {
+ assert(m);
+ assert(c);
+
+ assert(c->memblock);
+ assert(c->length > 0);
+
+ assert(!m->current.memblock);
+
+ /* Append to the leftover memory block */
+ if (m->leftover.memblock) {
+
+ /* Try to merge */
+ if (m->leftover.memblock == c->memblock &&
+ m->leftover.index + m->leftover.length == c->index) {
+
+ /* Merge */
+ m->leftover.length += c->length;
+
+ /* If the new chunk is larger than m->base, move it to current */
+ if (m->leftover.length >= m->base) {
+ m->current = m->leftover;
+ pa_memchunk_reset(&m->leftover);
+ }
+
+ } else {
+ size_t l;
+
+ /* We have to copy */
+ assert(m->leftover.length < m->base);
+ l = m->base - m->leftover.length;
+
+ if (l > c->length)
+ l = c->length;
+
+ /* Can we use the current block? */
+ pa_memchunk_make_writable(&m->leftover, m->memblock_stat, m->base);
+
+ memcpy((uint8_t*) m->leftover.memblock->data + m->leftover.index + m->leftover.length, (uint8_t*) c->memblock->data + c->index, l);
+ m->leftover.length += l;
+
+ assert(m->leftover.length <= m->base && m->leftover.length <= m->leftover.memblock->length);
+
+ if (c->length > l) {
+ /* Save the remainder of the memory block */
+ m->current = *c;
+ m->current.index += l;
+ m->current.length -= l;
+ pa_memblock_ref(m->current.memblock);
+ }
+ }
+ } else {
+ /* Nothing to merge or copy, just store it */
+
+ if (c->length >= m->base)
+ m->current = *c;
+ else
+ m->leftover = *c;
+
+ pa_memblock_ref(c->memblock);
+ }
+}
+
+int pa_mcalign_pop(pa_mcalign *m, pa_memchunk *c) {
+ assert(m);
+ assert(c);
+
+ /* First test if there's a leftover memory block available */
+ if (m->leftover.memblock) {
+ assert(m->leftover.length > 0 && m->leftover.length <= m->base);
+
+ /* The leftover memory block is not yet complete */
+ if (m->leftover.length < m->base)
+ return -1;
+
+ /* Return the leftover memory block */
+ *c = m->leftover;
+ pa_memchunk_reset(&m->leftover);
+
+ /* If the current memblock is too small move it the leftover */
+ if (m->current.memblock && m->current.length < m->base) {
+ m->leftover = m->current;
+ pa_memchunk_reset(&m->current);
+ }
+
+ return 0;
+ }
+
+ /* Now let's see if there is other data available */
+ if (m->current.memblock) {
+ size_t l;
+ assert(m->current.length >= m->base);
+
+ /* The length of the returned memory block */
+ l = m->current.length;
+ l /= m->base;
+ l *= m->base;
+ assert(l > 0);
+
+ /* Prepare the returned block */
+ *c = m->current;
+ pa_memblock_ref(c->memblock);
+ c->length = l;
+
+ /* Drop that from the current memory block */
+ assert(l <= m->current.length);
+ m->current.index += l;
+ m->current.length -= l;
+
+ /* In case the whole block was dropped ... */
+ if (m->current.length == 0)
+ pa_memblock_unref(m->current.memblock);
+ else {
+ /* Move the raimainder to leftover */
+ assert(m->current.length < m->base && !m->leftover.memblock);
+
+ m->leftover = m->current;
+ }
+
+ pa_memchunk_reset(&m->current);
+
+ return 0;
+ }
+
+ /* There's simply nothing */
+ return -1;
+
+}
+
+size_t pa_mcalign_csize(pa_mcalign *m, size_t l) {
+ assert(m);
+ assert(l > 0);
+
+ assert(!m->current.memblock);
+
+ if (m->leftover.memblock)
+ l += m->leftover.length;
+
+ return (l/m->base)*m->base;
+}