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Diffstat (limited to 'serve_image.c')
-rw-r--r--serve_image.c114
1 files changed, 63 insertions, 51 deletions
diff --git a/serve_image.c b/serve_image.c
index 57d2bd9..30ceaeb 100644
--- a/serve_image.c
+++ b/serve_image.c
@@ -36,36 +36,26 @@ int main(int argc, char **argv)
struct stat st;
int writeerrors = 0;
uint32_t erasesize;
- unsigned char *image, *blockptr;
+ unsigned char *image, *blockptr = NULL;
uint32_t block_nr, pkt_nr;
int nr_blocks;
struct timeval then, now, nextpkt;
long time_msecs;
- int pkts_extra = 6;
int pkts_per_block;
struct fec_parms *fec;
unsigned char *last_block;
uint32_t *block_crcs;
- int crcs_checked = 0;
long tosleep;
+ uint32_t sequence = 0;
- if (argc == 7) {
- tx_rate = atol(argv[6]) * 1024;
+ if (argc == 6) {
+ tx_rate = atol(argv[5]) * 1024;
if (tx_rate < PKT_SIZE || tx_rate > 20000000) {
fprintf(stderr, "Bogus TX rate %d KiB/s\n", tx_rate);
exit(1);
}
- argc = 6;
- }
- if (argc == 6) {
- pkts_extra = atol(argv[5]);
- if (pkts_extra < 0 || pkts_extra > 200) {
- fprintf(stderr, "Bogus redundancy %d packets\n", pkts_extra);
- exit(1);
- }
argc = 5;
}
-
if (argc != 5) {
fprintf(stderr, "usage: %s <host> <port> <image> <erasesize> [<redundancy>] [<tx_rate>]\n",
(strrchr(argv[0], '/')?:argv[0]-1)+1);
@@ -90,7 +80,7 @@ int main(int argc, char **argv)
exit(1);
}
- fec = fec_new(pkts_per_block, pkts_per_block + pkts_extra);
+ fec = fec_new(pkts_per_block, pkts_per_block * 2);
if (!fec) {
fprintf(stderr, "Error initialising FEC\n");
exit(1);
@@ -162,16 +152,23 @@ int main(int argc, char **argv)
pktbuf.hdr.nr_blocks = htonl(nr_blocks);
pktbuf.hdr.blocksize = htonl(erasesize);
pktbuf.hdr.thislen = htonl(PKT_SIZE);
- pktbuf.hdr.nr_pkts = htons(pkts_per_block + pkts_extra);
+ pktbuf.hdr.nr_pkts = htons(pkts_per_block * 2);
printf("%08x\n", ntohl(pktbuf.hdr.totcrc));
-
- again:
- printf("Image size %ld KiB (%08lx). %d redundant packets per block (%d total)\n"
- "Data to send %d KiB. Estimated transmit time: %ds\n",
- (long)st.st_size / 1024, (long) st.st_size, pkts_extra, pkts_extra+pkts_per_block,
- nr_blocks * PKT_SIZE * (pkts_per_block+pkts_extra) / 1024,
- nr_blocks * (pkts_per_block+pkts_extra) * pkt_delay / 1000000);
+ printf("Checking block CRCs....");
+ fflush(stdout);
+ for (block_nr=0; block_nr < nr_blocks; block_nr++) {
+ printf("\rChecking block CRCS.... %d/%d",
+ block_nr + 1, nr_blocks);
+ fflush(stdout);
+ block_crcs[block_nr] = crc32(-1, image + (block_nr * erasesize), erasesize);
+ }
+
+ printf("\nImage size %ld KiB (0x%08lx). %d blocks at %d pkts/block\n"
+ "Estimated transmit time per cycle: %ds\n",
+ (long)st.st_size / 1024, (long) st.st_size,
+ nr_blocks, pkts_per_block,
+ nr_blocks * pkts_per_block * pkt_delay / 1000000);
gettimeofday(&then, NULL);
nextpkt = then;
@@ -179,47 +176,69 @@ int main(int argc, char **argv)
srand((unsigned)then.tv_usec);
printf("Random seed %u\n", (unsigned)then.tv_usec);
#endif
- blockptr = image;
+ while (1) for (pkt_nr=0; pkt_nr < pkts_per_block * 2; pkt_nr++) {
+
+ if (blockptr && pkt_nr == 0) {
+ unsigned long amt_sent = pkts_per_block * nr_blocks * sizeof(pktbuf) * 2;
+ gettimeofday(&now, NULL);
- for (block_nr = 0; block_nr < nr_blocks; block_nr++) {
+ time_msecs = (now.tv_sec - then.tv_sec) * 1000;
+ time_msecs += ((int)(now.tv_usec - then.tv_usec)) / 1000;
+ printf("\n%ld KiB sent in %ldms (%ld KiB/s)\n",
+ amt_sent / 1024, time_msecs,
+ amt_sent / 1024 * 1000 / time_msecs);
+ then = now;
+ }
+
+ for (block_nr = 0; block_nr < nr_blocks; block_nr++) {
+
+ int actualpkt;
- for (pkt_nr=0; pkt_nr < pkts_per_block + pkts_extra; pkt_nr++) {
+ /* Calculating the redundant FEC blocks is expensive;
+ the first $pkts_per_block are cheap enough though
+ because they're just copies. So alternate between
+ simple and complex stuff, so that we don't start
+ to choke and fail to keep up with the expected
+ bitrate in the second half of the sequence */
+ if (block_nr & 1)
+ actualpkt = pkt_nr;
+ else if (pkt_nr >= pkts_per_block)
+ actualpkt = pkt_nr - pkts_per_block;
+ else
+ actualpkt = pkt_nr + pkts_per_block;
blockptr = image + (erasesize * block_nr);
if (block_nr == nr_blocks - 1)
blockptr = last_block;
- /* Calculate the block CRCs first time around */
- if (block_nr >= crcs_checked) {
- block_crcs[block_nr] = crc32(-1, blockptr, erasesize);
- crcs_checked = block_nr + 1;
- }
+ fec_encode_linear(fec, blockptr, pktbuf.data, actualpkt, PKT_SIZE);
+ pktbuf.hdr.thiscrc = htonl(crc32(-1, pktbuf.data, PKT_SIZE));
pktbuf.hdr.block_crc = htonl(block_crcs[block_nr]);
pktbuf.hdr.block_nr = htonl(block_nr);
+ pktbuf.hdr.pkt_nr = htons(actualpkt);
+ pktbuf.hdr.pkt_sequence = htonl(sequence++);
- fec_encode_linear(fec, blockptr, pktbuf.data, pkt_nr, PKT_SIZE);
-
printf("\rSending data block %08x packet %3d/%d",
- block_nr * erasesize, pkt_nr, pkts_per_block + pkts_extra);
+ block_nr * erasesize,
+ pkt_nr, pkts_per_block * 2);
+
+ if (pkt_nr && !block_nr) {
+ unsigned long amt_sent = pkt_nr * nr_blocks * sizeof(pktbuf);
- if (block_nr && !pkt_nr) {
gettimeofday(&now, NULL);
time_msecs = (now.tv_sec - then.tv_sec) * 1000;
time_msecs += ((int)(now.tv_usec - then.tv_usec)) / 1000;
printf(" (%ld KiB/s) ",
- (block_nr * sizeof(pktbuf) * (pkts_per_block+pkts_extra))
- / 1024 * 1000 / time_msecs);
+ amt_sent / 1024 * 1000 / time_msecs);
}
fflush(stdout);
- pktbuf.hdr.pkt_nr = htons(pkt_nr);
- pktbuf.hdr.thiscrc = htonl(crc32(-1, pktbuf.data, PKT_SIZE));
#ifdef RANDOMDROP
if ((rand() % 1000) < 20) {
- printf("\nDropping packet %d\n", pkt_nr+1);
+ printf("\nDropping packet %d of block %08x\n", pkt_nr+1, block_nr * erasesize);
continue;
}
#endif
@@ -251,9 +270,10 @@ int main(int argc, char **argv)
}
/* If the time for the next packet has already
- passed, then we've lost time. Adjust our expected
- timings accordingly. */
- if (now.tv_usec > (now.tv_usec +
+ passed (by some margin), then we've lost time
+ Adjust our expected timings accordingly. If
+ we're only a little way behind, don't slip yet */
+ if (now.tv_usec > (now.tv_usec + (5 * pkt_delay) +
1000000 * (nextpkt.tv_sec - now.tv_sec))) {
nextpkt = now;
}
@@ -272,14 +292,6 @@ int main(int argc, char **argv)
}
}
- gettimeofday(&now, NULL);
-
- time_msecs = (now.tv_sec - then.tv_sec) * 1000;
- time_msecs += ((int)(now.tv_usec - then.tv_usec)) / 1000;
- printf("\n%d KiB sent in %ldms (%ld KiB/s)\n",
- nr_blocks * sizeof(pktbuf) * (pkts_per_block+pkts_extra) / 1024, time_msecs,
- nr_blocks * sizeof(pktbuf) * (pkts_per_block+pkts_extra) / 1024 * 1000 / time_msecs);
-
munmap(image, st.st_size);
close(rfd);
close(sock);
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-13 16:51:30 +0000