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/* $Id$ */
/***
This file is part of PulseAudio.
Copyright 2004-2006 Lennart Poettering
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_mcalign *pa_mcalign_new(size_t base) {
pa_mcalign *m;
assert(base);
m = pa_xnew(pa_mcalign, 1);
m->base = base;
pa_memchunk_reset(&m->leftover);
pa_memchunk_reset(&m->current);
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->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;
}
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