mirror of
https://github.com/ericonr/sndio.git
synced 2024-02-18 04:45:21 -06:00
139 lines
3.0 KiB
C
139 lines
3.0 KiB
C
/* $OpenBSD$ */
|
|
/*
|
|
* Copyright (c) 2008-2012 Alexandre Ratchov <alex@caoua.org>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
/*
|
|
* Simple byte fifo.
|
|
*
|
|
* The abuf data is split in two parts: (1) valid data available to the reader
|
|
* (2) space available to the writer, which is not necessarily unused. It works
|
|
* as follows: the write starts filling at offset (start + used), once the data
|
|
* is ready, the writer adds to used the count of bytes available.
|
|
*/
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include "abuf.h"
|
|
#include "utils.h"
|
|
|
|
#ifdef DEBUG
|
|
void
|
|
abuf_log(struct abuf *buf)
|
|
{
|
|
log_putu(buf->start);
|
|
log_puts("+");
|
|
log_putu(buf->used);
|
|
log_puts("/");
|
|
log_putu(buf->len);
|
|
}
|
|
#endif
|
|
|
|
void
|
|
abuf_init(struct abuf *buf, unsigned int len)
|
|
{
|
|
buf->data = xmalloc(len);
|
|
buf->len = len;
|
|
buf->used = 0;
|
|
buf->start = 0;
|
|
}
|
|
|
|
void
|
|
abuf_done(struct abuf *buf)
|
|
{
|
|
#ifdef DEBUG
|
|
if (buf->used > 0) {
|
|
if (log_level >= 3) {
|
|
log_puts("deleting non-empty buffer, used = ");
|
|
log_putu(buf->used);
|
|
log_puts("\n");
|
|
}
|
|
}
|
|
#endif
|
|
xfree(buf->data);
|
|
buf->data = (void *)0xdeadbeef;
|
|
}
|
|
|
|
/*
|
|
* return the reader pointer and the number of bytes available
|
|
*/
|
|
unsigned char *
|
|
abuf_rgetblk(struct abuf *buf, int *rsize)
|
|
{
|
|
int count;
|
|
|
|
count = buf->len - buf->start;
|
|
if (count > buf->used)
|
|
count = buf->used;
|
|
*rsize = count;
|
|
return buf->data + buf->start;
|
|
}
|
|
|
|
/*
|
|
* discard "count" bytes at the start postion.
|
|
*/
|
|
void
|
|
abuf_rdiscard(struct abuf *buf, int count)
|
|
{
|
|
#ifdef DEBUG
|
|
if (count < 0 || count > buf->used) {
|
|
log_puts("abuf_rdiscard: bad count = ");
|
|
log_putu(count);
|
|
log_puts("\n");
|
|
panic();
|
|
}
|
|
#endif
|
|
buf->used -= count;
|
|
buf->start += count;
|
|
if (buf->start >= buf->len)
|
|
buf->start -= buf->len;
|
|
}
|
|
|
|
/*
|
|
* advance the writer pointer by "count" bytes
|
|
*/
|
|
void
|
|
abuf_wcommit(struct abuf *buf, int count)
|
|
{
|
|
#ifdef DEBUG
|
|
if (count < 0 || count > (buf->len - buf->used)) {
|
|
log_puts("abuf_wcommit: bad count = ");
|
|
log_putu(count);
|
|
log_puts("\n");
|
|
panic();
|
|
}
|
|
#endif
|
|
buf->used += count;
|
|
}
|
|
|
|
/*
|
|
* get writer pointer and the number of bytes writable
|
|
*/
|
|
unsigned char *
|
|
abuf_wgetblk(struct abuf *buf, int *rsize)
|
|
{
|
|
int end, avail, count;
|
|
|
|
end = buf->start + buf->used;
|
|
if (end >= buf->len)
|
|
end -= buf->len;
|
|
avail = buf->len - buf->used;
|
|
count = buf->len - end;
|
|
if (count > avail)
|
|
count = avail;
|
|
*rsize = count;
|
|
return buf->data + end;
|
|
}
|