sox_ng/src/fifo.c
2025-12-10 02:21:30 +01:00

103 lines
2.4 KiB
C

/* Addressable FIFO buffer Copyright (c) 2007 robs@users.sourceforge.net
*
* This library 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.
*
* This library 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 this library; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "sox_i.h"
#include "fifo.h"
#define FIFO_MIN 0x4000
void lsx_fifo_clear(fifo_t * f)
{
f->end = f->begin = 0;
free(f->data);
f->data = NULL;
f->allocation = 0;
}
void * lsx_fifo_reserve(fifo_t * f, size_t n)
{
n *= f->item_size;
if (f->begin == f->end)
lsx_fifo_clear(f);
while (1) {
if (f->end + n <= f->allocation) {
void *p = f->data + f->end;
f->end += n;
return p;
}
if (f->begin > FIFO_MIN) {
memmove(f->data, f->data + f->begin, f->end - f->begin);
f->end -= f->begin;
f->begin = 0;
continue;
}
if (f->allocation == 0) f->allocation = FIFO_MIN;
while (f->allocation < f->end + n) f->allocation *= 2;
f->data = lsx_realloc(f->data, f->allocation);
}
}
void * lsx_fifo_write(fifo_t * f, size_t n, void const * data)
{
void * s = lsx_fifo_reserve(f, n);
if (data)
memcpy(s, data, n * f->item_size);
return s;
}
void lsx_fifo_trim_to(fifo_t * f, size_t n)
{
n *= f->item_size;
f->end = f->begin + n;
}
void lsx_fifo_trim_by(fifo_t * f, size_t n)
{
n *= f->item_size;
f->end -= n;
}
size_t lsx_fifo_occupancy(fifo_t * f)
{
return (f->end - f->begin) / f->item_size;
}
void * lsx_fifo_read(fifo_t * f, size_t n, void * data)
{
char * ret = f->data + f->begin;
n *= f->item_size;
if (n > (size_t)(f->end - f->begin))
return NULL;
if (data)
memcpy(data, ret, (size_t)n);
f->begin += n;
return ret;
}
void lsx_fifo_delete(fifo_t * f)
{
free(f->data);
}
void lsx_fifo_create(fifo_t * f, size_t item_size)
{
f->item_size = item_size;
lsx_fifo_clear(f);
}