tvheadend/src/htsbuf.c

332 lines
5.9 KiB
C

/*
* Buffer management functions
* Copyright (C) 2008 Andreas Öman
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include "htsbuf.h"
#include "tvheadend.h"
#ifndef MIN
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#endif
#ifndef MAX
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#endif
/**
*
*/
void
htsbuf_queue_init(htsbuf_queue_t *hq, unsigned int maxsize)
{
if(maxsize == 0)
maxsize = INT32_MAX;
TAILQ_INIT(&hq->hq_q);
hq->hq_size = 0;
hq->hq_maxsize = maxsize;
}
/**
*
*/
htsbuf_queue_t *
htsbuf_queue_alloc(unsigned int maxsize)
{
htsbuf_queue_t *hq = malloc(sizeof(htsbuf_queue_t));
htsbuf_queue_init(hq, maxsize);
return hq;
}
/**
*
*/
void
htsbuf_data_free(htsbuf_queue_t *hq, htsbuf_data_t *hd)
{
TAILQ_REMOVE(&hq->hq_q, hd, hd_link);
free(hd->hd_data);
free(hd);
}
/**
*
*/
void
htsbuf_queue_flush(htsbuf_queue_t *hq)
{
htsbuf_data_t *hd;
hq->hq_size = 0;
while((hd = TAILQ_FIRST(&hq->hq_q)) != NULL)
htsbuf_data_free(hq, hd);
}
/**
*
*/
void
htsbuf_append(htsbuf_queue_t *hq, const void *buf, size_t len)
{
htsbuf_data_t *hd = TAILQ_LAST(&hq->hq_q, htsbuf_data_queue);
int c;
hq->hq_size += len;
if(hd != NULL) {
/* Fill out any previous buffer */
c = MIN(hd->hd_data_size - hd->hd_data_len, len);
memcpy(hd->hd_data + hd->hd_data_len, buf, c);
hd->hd_data_len += c;
buf += c;
len -= c;
}
if(len == 0)
return;
hd = malloc(sizeof(htsbuf_data_t));
TAILQ_INSERT_TAIL(&hq->hq_q, hd, hd_link);
c = MAX(len, 1000); /* Allocate 1000 bytes to support lots of small writes */
hd->hd_data = malloc(c);
hd->hd_data_size = c;
hd->hd_data_len = len;
hd->hd_data_off = 0;
memcpy(hd->hd_data, buf, len);
}
/**
*
*/
void
htsbuf_append_prealloc(htsbuf_queue_t *hq, const void *buf, size_t len)
{
htsbuf_data_t *hd;
hq->hq_size += len;
hd = malloc(sizeof(htsbuf_data_t));
TAILQ_INSERT_TAIL(&hq->hq_q, hd, hd_link);
hd->hd_data = (void *)buf;
hd->hd_data_size = len;
hd->hd_data_len = len;
hd->hd_data_off = 0;
}
/**
*
*/
size_t
htsbuf_read(htsbuf_queue_t *hq, void *buf, size_t len)
{
size_t r = 0;
int c;
htsbuf_data_t *hd;
while(len > 0) {
hd = TAILQ_FIRST(&hq->hq_q);
if(hd == NULL)
break;
c = MIN(hd->hd_data_len - hd->hd_data_off, len);
memcpy(buf, hd->hd_data + hd->hd_data_off, c);
r += c;
buf += c;
len -= c;
hd->hd_data_off += c;
hq->hq_size -= c;
if(hd->hd_data_off == hd->hd_data_len)
htsbuf_data_free(hq, hd);
}
return r;
}
/**
*
*/
size_t
htsbuf_find(htsbuf_queue_t *hq, uint8_t v)
{
htsbuf_data_t *hd;
int i, o = 0;
TAILQ_FOREACH(hd, &hq->hq_q, hd_link) {
for(i = hd->hd_data_off; i < hd->hd_data_len; i++) {
if(hd->hd_data[i] == v)
return o + i - hd->hd_data_off;
}
o += hd->hd_data_len - hd->hd_data_off;
}
return -1;
}
/**
*
*/
size_t
htsbuf_peek(htsbuf_queue_t *hq, void *buf, size_t len)
{
size_t r = 0;
int c;
htsbuf_data_t *hd = TAILQ_FIRST(&hq->hq_q);
while(len > 0 && hd != NULL) {
c = MIN(hd->hd_data_len - hd->hd_data_off, len);
memcpy(buf, hd->hd_data + hd->hd_data_off, c);
buf += c;
len -= c;
hd = TAILQ_NEXT(hd, hd_link);
}
return r;
}
/**
*
*/
size_t
htsbuf_drop(htsbuf_queue_t *hq, size_t len)
{
size_t r = 0;
int c;
htsbuf_data_t *hd;
while(len > 0) {
hd = TAILQ_FIRST(&hq->hq_q);
if(hd == NULL)
break;
c = MIN(hd->hd_data_len - hd->hd_data_off, len);
len -= c;
hd->hd_data_off += c;
hq->hq_size -= c;
if(hd->hd_data_off == hd->hd_data_len)
htsbuf_data_free(hq, hd);
}
return r;
}
/**
* Inspired by vsnprintf man page
*/
void
htsbuf_vqprintf(htsbuf_queue_t *hq, const char *fmt, va_list ap0)
{
// First try to format it on-stack
va_list ap;
int n, size;
char buf[100], *p, *np;
va_copy(ap, ap0);
n = vsnprintf(buf, sizeof(buf), fmt, ap);
if(n > -1 && n < sizeof(buf)) {
htsbuf_append(hq, buf, n);
return;
}
// Else, do allocations
size = sizeof(buf) * 2;
p = malloc(size);
while (1) {
/* Try to print in the allocated space. */
va_copy(ap, ap0);
n = vsnprintf(p, size, fmt, ap);
if(n > -1 && n < size) {
htsbuf_append_prealloc(hq, p, n);
return;
}
/* Else try again with more space. */
if (n > -1) /* glibc 2.1 */
size = n+1; /* precisely what is needed */
else /* glibc 2.0 */
size *= 2; /* twice the old size */
if ((np = realloc (p, size)) == NULL) {
free(p);
abort();
} else {
p = np;
}
}
}
/**
*
*/
void
htsbuf_qprintf(htsbuf_queue_t *hq, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
htsbuf_vqprintf(hq, fmt, ap);
va_end(ap);
}
void
htsbuf_appendq(htsbuf_queue_t *hq, htsbuf_queue_t *src)
{
htsbuf_data_t *hd;
hq->hq_size += src->hq_size;
src->hq_size = 0;
while((hd = TAILQ_FIRST(&src->hq_q)) != NULL) {
TAILQ_REMOVE(&src->hq_q, hd, hd_link);
TAILQ_INSERT_TAIL(&hq->hq_q, hd, hd_link);
}
}
/**
*
*/
uint32_t
htsbuf_crc32(htsbuf_queue_t *hq, uint32_t crc)
{
htsbuf_data_t *hd;
TAILQ_FOREACH(hd, &hq->hq_q, hd_link)
crc = crc32(hd->hd_data + hd->hd_data_off,
hd->hd_data_len - hd->hd_data_off,
crc);
return crc;
}