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/*C
(c) 2005 bl0rg.net
**/
#include "conf.h"
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "rtp.h"
/*M
\emph{Maximal number of elements in the ring buffer.}
**/
unsigned int rtp_rb_size = 0;
/*M
\emph{Index of first valid element in ring buffer.}
**/
static unsigned int rtp_rb_start = 0;
/*M
\emph{Index of first invalid element in ring buffer.}
**/
static unsigned int rtp_rb_end = 0;
/*M
\emph{Number of elements in the ring buffer.}
**/
unsigned int rtp_rb_cnt = 0;
/*M
\emph{Ring buffer array.}
**/
rtp_pkt_t *rtp_rb = NULL;
void rtp_rb_clear(void) {
rtp_rb_start = 0;
rtp_rb_end = 0;
rtp_rb_cnt = 0;
int i;
for (i = 0; i < rtp_rb_size; i++) {
rtp_pkt_init(rtp_rb + i);
rtp_rb[i].length = 0;
}
}
void rtp_rb_destroy(void) {
if (rtp_rb != NULL) {
free(rtp_rb);
rtp_rb = NULL;
}
rtp_rb_size = 0;
rtp_rb_clear();
}
void rtp_rb_init(unsigned int size) {
rtp_rb_destroy();
rtp_rb = malloc(sizeof(rtp_pkt_t) * size);
assert(rtp_rb != NULL);
rtp_rb_size = size;
rtp_rb_clear();
}
unsigned int rtp_rb_length(void) {
assert(rtp_rb != NULL);
if (rtp_rb_end >= rtp_rb_start)
return rtp_rb_end - rtp_rb_start;
else
return rtp_rb_end + (rtp_rb_size - rtp_rb_start);
}
void rtp_rb_pop(void) {
assert(rtp_rb != NULL);
assert(rtp_rb_end != rtp_rb_start);
rtp_rb[rtp_rb_start].length = 0;
rtp_rb_start = (rtp_rb_start + 1) % rtp_rb_size;
rtp_rb_cnt--;
}
int rtp_rb_insert_pkt(rtp_pkt_t *pkt, int idx) {
assert(pkt != NULL);
assert(rtp_rb != NULL);
#ifdef DEBUG
fprintf(stderr, "insert packet at idx %d\n", idx);
#endif
if (idx < 0) {
/* try to grow the buffer downwards */
if ((rtp_rb_length() - idx) <= rtp_rb_size) {
rtp_rb_start = (rtp_rb_start + idx) % rtp_rb_size;
idx = 0;
} else
/* drop the packet silently */
return 0;
} else if (idx >= rtp_rb_size - 1) {
/* not enough place left in ring buffer */
return 0;
}
rtp_pkt_t *dstpkt = rtp_rb + ((idx + rtp_rb_start) % rtp_rb_size);
assert(dstpkt->length == 0);
memcpy(dstpkt, pkt, sizeof(rtp_pkt_t));
rtp_rb_cnt++;
#ifdef DEBUG
fprintf(stderr, "packet inserted at %d, end: %d\n",
(idx + rtp_rb_start) % rtp_rb_size,
rtp_rb_end);
#endif
/* adjust the end pointer */
if (idx >= rtp_rb_length())
rtp_rb_end = ((idx + rtp_rb_start + 1)% rtp_rb_size);
assert(rtp_rb_start != rtp_rb_end);
assert(rtp_rb[rtp_rb_end].length == 0);
return 1;
}
void rtp_rb_print(void) {
assert(rtp_rb != NULL);
fprintf(stderr, "start: %.3u, end: %.3u, len: %.3u\n",
rtp_rb_start, rtp_rb_end, rtp_rb_length());
}
void rtp_rb_print_rb(void) {
unsigned int i;
for (i = rtp_rb_start; i != rtp_rb_end; i = (i + 1) % rtp_rb_size) {
if (rtp_rb[i].length != 0)
fprintf(stderr, "%.3u: seq %.3u\n", i, rtp_rb[i].b.seq);
}
}
rtp_pkt_t *rtp_rb_first(void) {
assert(rtp_rb != NULL);
if (rtp_rb_start == rtp_rb_end)
return NULL;
/* first should always be the first in buffer */
return rtp_rb + rtp_rb_start;
}
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