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New API calls burn_write_opts_set_dvd_obs(), burn_write_opts_set_stdio_fsync()

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This commit is contained in:
Thomas Schmitt
2009-11-15 15:30:26 +00:00
parent 738b83ac03
commit 79a33ca2ac
5 changed files with 210 additions and 7 deletions
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148
libburn/write.c
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@ -1246,6 +1246,126 @@ int burn_disc_close_track_dvd_plus_r(struct burn_write_opts *o,
}
/* <<<
#define Libburn_simplified_dvd_chunk_transactioN 1
*/
#ifdef Libburn_simplified_dvd_chunk_transactioN
/* ts A91114 : EXPERIMENTAL, NOT COMPLETELY IMPLEMENTED
Simplified data transmission for DVD. libburn via Linux USB is 30 % slower
than growisofs or cdrecord when transmitting 32 KB chunks.
With 64 KB chunks it is 20% faster than the competitors.
No heavy CPU load is visible but there might be subtle race conditions in
the USB driver which work better with shorter time gaps between WRITE
commands.
Insight: It is actually about the interference of track source reading
with SCSI writing via USB. growisofs reads with O_DIRECT into a
mmap()ed buffer. When doing the same, libburn with 32 KB chunks
reaches similar write speed.
On the other hand, 64 KB chunks are 20% faster than that and
are not improved by reading O_DIRECT.
O_DIRECT is a property of the input fd of struct burn_source.
It can only be done with properly aligned memory and with aligned
read size. Alignment size is file system system specific.
System call
mmap(NULL, (size_t) buffer_size, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, (off_t) 0);
is supposed to allocate a properly aligned buffer.
64 KB is supposed to be a safe size.
@return 1= ok, go on , 2= no input with track->open_ended = nothing written
<= 0 = error
*/
static int transact_dvd_chunk(struct burn_write_opts *opts,
struct burn_track *track)
{
int curr = 0, valid, err;
struct burn_drive *d = opts->drive;
struct buffer *out = d->buffer;
unsigned char *data = out->data;
#ifdef Libburn_log_in_and_out_streaM
/* <<< ts A61031 */
static int tee_fd= -1;
if(tee_fd==-1)
tee_fd= open("/tmp/libburn_sg_readin",
O_WRONLY|O_CREAT|O_TRUNC,S_IRUSR|S_IWUSR);
#endif /* Libburn_log_in_and_out_streaM */
/* Read a chunk full of data */
/* ??? Do we have offset padding ? >>> First produce offset padding */;
/* <<<< */
if (0 && !track->eos) {
for (curr = 0; curr < opts->obs; curr += 2048) {
if (track->source->read != NULL)
valid = track->source->read(track->source,
data + curr, 2048);
else
valid = track->source->read_xt(track->source,
data + curr, 2048);
if (valid <= 0) {
track->eos = 1;
break;
}
track->sourcecount += valid;
#ifdef Libburn_log_in_and_out_streaM
if(tee_fd!=-1 && valid>0) {
write(tee_fd, data + curr, valid);
}
#endif /* Libburn_log_in_and_out_streaM */
}
} else if (!track->eos){
valid = track->source->read(track->source, data, opts->obs);
if (valid <= 0) {
track->eos = 1;
} else {
track->sourcecount += valid;
curr = valid;
#ifdef Libburn_log_in_and_out_streaM
if(tee_fd!=-1 && valid>0) {
write(tee_fd, data, valid);
}
#endif /* Libburn_log_in_and_out_streaM */
}
}
if (curr == 0 && track->open_ended) {
/* >>> allow tail padding */;
return 2;
}
if (curr < opts->obs)
memset(data + curr , 0, opts->obs - curr);
/* Write chunk */
out->bytes = opts->obs;
out->sectors = out->bytes / 2048;
err = d->write(d, d->nwa, out);
if (err == BE_CANCELLED)
return 0;
track->writecount += out->bytes;
track->written_sectors += out->sectors;
d->progress.buffered_bytes += out->bytes;
d->nwa += out->sectors;
out->bytes = 0;
out->sectors = 0;
return 1;
}
#endif /* Libburn_simplified_dvd_chunk_transactioN */
/* ts A61218 - A81208 */
int burn_dvd_write_track(struct burn_write_opts *o,
struct burn_session *s, int tnum, int is_last_track)
@ -1322,9 +1442,18 @@ int burn_dvd_write_track(struct burn_write_opts *o,
d->progress.buffer_capacity / 2048 + 128;
}
#ifdef Libburn_simplified_dvd_chunk_transactioN
ret = transact_dvd_chunk(o, t);
if (ret <= 0)
{ret = 0; goto ex;}
i += o->obs / 2048 - 1;
d->progress.sector += o->obs / 2048 - 1;
#else
/* transact a (CD sized) sector */
if (!sector_data(o, t, 0))
{ ret = 0; goto ex; }
#endif
if (open_ended) {
d->progress.sectors = sectors = i;
@ -1789,11 +1918,22 @@ int burn_dvd_write_sync(struct burn_write_opts *o,
/* <<< test only : Does this increase effective speed with USB ?
ts A90801 : 64kB: speed with 16x DVD-R is 12 rather than 8
128kB: glibc complains about double free
BURN_OS_TRANSPORT_BUFFER_SIZE would need to
be enlarged anyway.
With BURN_OS_TRANSPORT_BUFFER_SIZE
enlarged to 128 MB, the first WRITE fails
with an i/o error.
o->obs = 64 * 1024;
*/
if (o->dvd_obs_override >= 32 * 1024)
o->obs = o->dvd_obs_override;
if (o->obs > BUFFER_SIZE) {
sprintf(msg, "Chosen write chunk size %d exceeds system dependent buffer size", o->obs);
libdax_msgs_submit(libdax_messenger, d->global_index,
0x00000002, LIBDAX_MSGS_SEV_DEBUG,
LIBDAX_MSGS_PRIO_ZERO, msg, 0, 0);
o->obs = BUFFER_SIZE;
}
sprintf(msg, "dvd/bd Profile= %2.2Xh , obs= %d , obs_pad= %d",
d->current_profile, o->obs, o->obs_pad);
@ -2043,8 +2183,6 @@ int burn_stdio_slowdown(struct burn_drive *d, struct timeval *prev_time,
return 1;
}
/* Flush write buffer after each 16 MB */
#define Libburn_stdio_flush_limiT 8192
/* ts A70904 */
int burn_stdio_write_track(struct burn_write_opts *o, struct burn_session *s,
@ -2085,7 +2223,7 @@ int burn_stdio_write_track(struct burn_write_opts *o, struct burn_session *s,
d->progress.sector++;
/* Flush to disk from time to time */
if (d->progress.sector - prev_sync_sector >=
Libburn_stdio_flush_limiT) {
o->stdio_fsync_size && o->stdio_fsync_size > 0) {
prev_sync_sector = d->progress.sector;
if (!o->simulate)
burn_stdio_sync_cache(d->stdio_fd, d, 1);