busybox/archival/bzip2.c
2007-10-14 00:43:01 +00:00

183 lines
4.2 KiB
C

/*
* Copyright (C) 2007 Denys Vlasenko <vda.linux@googlemail.com>
*
* This file uses bzip2 library code which is written
* by Julian Seward <jseward@bzip.org>.
* See README and LICENSE files in bz/ directory for more information
* about bzip2 library code.
*/
#include "libbb.h"
#define CONFIG_BZIP2_FEATURE_SPEED 1
/* Speed test:
* Compiled with gcc 4.2.1, run on Athlon 64 1800 MHz (512K L2 cache).
* Stock bzip2 is 26.4% slower than bbox bzip2 at SPEED 1
* (time to compress gcc-4.2.1.tar is 126.4% compared to bbox).
* At SPEED 5 difference is 32.7%.
*
* Test run of all CONFIG_BZIP2_FEATURE_SPEED values on a 11Mb text file:
* Size Time (3 runs)
* 0: 10828 4.145 4.146 4.148
* 1: 11097 3.845 3.860 3.861
* 2: 11392 3.763 3.767 3.768
* 3: 11892 3.722 3.724 3.727
* 4: 12740 3.637 3.640 3.644
* 5: 17273 3.497 3.509 3.509
*/
#define BZ_DEBUG 0
/* Takes ~300 bytes, detects corruption caused by bad RAM etc */
#define BZ_LIGHT_DEBUG 0
#include "bz/bzlib.h"
#include "bz/bzlib_private.h"
#include "bz/blocksort.c"
#include "bz/bzlib.c"
#include "bz/compress.c"
#include "bz/huffman.c"
/* No point in being shy and having very small buffer here.
* bzip2 internal buffers are much bigger anyway, hundreds of kbytes.
* If iobuf is several pages long, malloc() may use mmap,
* making iobuf is page aligned and thus (maybe) have one memcpy less
* if kernel is clever enough.
*/
enum {
IOBUF_SIZE = 8 * 1024
};
/* Returns:
* <0 on write errors (examine errno),
* >0 on short writes (errno == 0)
* 0 no error (entire input consumed, gimme more)
* on "impossible" errors (internal bzip2 compressor bug) dies
*/
static
ssize_t bz_write(bz_stream *strm, void* rbuf, ssize_t rlen, void *wbuf)
{
int n, n2, ret;
strm->avail_in = rlen;
strm->next_in = rbuf;
while (1) {
strm->avail_out = IOBUF_SIZE;
strm->next_out = wbuf;
ret = BZ2_bzCompress(strm, BZ_RUN);
if (ret != BZ_RUN_OK)
bb_error_msg_and_die("internal error %d", ret);
n = IOBUF_SIZE - strm->avail_out;
if (n) {
/* short reads must have errno == 0 */
errno = 0;
n2 = full_write(STDOUT_FILENO, wbuf, n);
if (n2 != n)
return n2 ? n2 : 1;
}
if (strm->avail_in == 0)
return 0;
}
}
/*---------------------------------------------------*/
static
USE_DESKTOP(long long) int bz_write_tail(bz_stream *strm, void *wbuf)
{
int n, n2, ret;
USE_DESKTOP(long long) int total;
total = -1;
while (1) {
strm->avail_out = IOBUF_SIZE;
strm->next_out = wbuf;
ret = BZ2_bzCompress(strm, BZ_FINISH);
if (ret != BZ_FINISH_OK && ret != BZ_STREAM_END)
bb_error_msg_and_die("internal error %d", ret);
n = IOBUF_SIZE - strm->avail_out;
if (n) {
n2 = full_write(STDOUT_FILENO, wbuf, n);
if (n2 != n)
goto err;
}
if (ret == BZ_STREAM_END)
break;
}
total = 0 USE_DESKTOP( + strm->total_out );
err:
BZ2_bzCompressEnd(strm);
return total;
}
static
USE_DESKTOP(long long) int compressStream(void)
{
USE_DESKTOP(long long) int total;
ssize_t count;
bz_stream bzs; /* it's small */
#define strm (&bzs)
char *iobuf;
#define rbuf iobuf
#define wbuf (iobuf + IOBUF_SIZE)
iobuf = xmalloc(2 * IOBUF_SIZE);
BZ2_bzCompressInit(strm, 9 /*blockSize100k*/);
while (1) {
count = full_read(STDIN_FILENO, rbuf, IOBUF_SIZE);
if (count < 0)
bb_perror_msg("read error");
if (count <= 0)
break;
count = bz_write(strm, rbuf, count, wbuf);
if (count) {
bb_perror_msg(count < 0 ? "write error" : "short write");
break;
}
}
total = bz_write_tail(strm, wbuf);
free(iobuf);
/* we had no error _only_ if count == 0 */
return count == 0 ? total : -1;
}
static
char* make_new_name_bzip2(char *filename)
{
return xasprintf("%s.bz2", filename);
}
int bzip2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int bzip2_main(int argc, char **argv)
{
unsigned opt;
/* Must match bbunzip's constants OPT_STDOUT, OPT_FORCE! */
opt = getopt32(argv, "cfv" USE_BUNZIP2("d") "q123456789" );
#if ENABLE_BUNZIP2 /* bunzip2_main may not be visible... */
if (opt & 0x8) // -d
return bunzip2_main(argc, argv);
#endif
option_mask32 &= 0x7; /* ignore -q, -0..9 */
//if (opt & 0x1) // -c
//if (opt & 0x2) // -f
//if (opt & 0x4) // -v
argv += optind;
return bbunpack(argv, make_new_name_bzip2, compressStream);
}