aboutsummaryrefslogtreecommitdiff
path: root/archival/bzip2.c
blob: ac5db0880cea46301486a25c8dde8eeff7eac111 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
/*
 * 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.
 */
//config:config BZIP2
//config:	bool "bzip2 (16 kb)"
//config:	default y
//config:	help
//config:	bzip2 is a compression utility using the Burrows-Wheeler block
//config:	sorting text compression algorithm, and Huffman coding. Compression
//config:	is generally considerably better than that achieved by more
//config:	conventional LZ77/LZ78-based compressors, and approaches the
//config:	performance of the PPM family of statistical compressors.
//config:
//config:	Unless you have a specific application which requires bzip2, you
//config:	should probably say N here.
//config:
//config:config BZIP2_SMALL
//config:	int "Trade bytes for speed (0:fast, 9:small)"
//config:	default 8  # all "fast or small" options default to small
//config:	range 0 9
//config:	depends on BZIP2
//config:	help
//config:	Trade code size versus speed.
//config:	Approximate values with gcc-6.3.0 "bzip -9" compressing
//config:	linux-4.15.tar were:
//config:	value         time (sec)  code size (386)
//config:	9 (smallest)       70.11             7687
//config:	8                  67.93             8091
//config:	7                  67.88             8405
//config:	6                  67.78             8624
//config:	5                  67.05             9427
//config:	4-0 (fastest)      64.14            12083
//config:
//config:config FEATURE_BZIP2_DECOMPRESS
//config:	bool "Enable decompression"
//config:	default y
//config:	depends on BZIP2 || BUNZIP2 || BZCAT
//config:	help
//config:	Enable -d (--decompress) and -t (--test) options for bzip2.
//config:	This will be automatically selected if bunzip2 or bzcat is
//config:	enabled.

//applet:IF_BZIP2(APPLET(bzip2, BB_DIR_USR_BIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_BZIP2) += bzip2.o

//usage:#define bzip2_trivial_usage
//usage:       "[-cfk" IF_FEATURE_BZIP2_DECOMPRESS("dt") "123456789] [FILE]..."
//usage:#define bzip2_full_usage "\n\n"
//usage:       "Compress FILEs (or stdin) with bzip2 algorithm\n"
//usage:     "\n	-1..9	Compression level"
//usage:	IF_FEATURE_BZIP2_DECOMPRESS(
//usage:     "\n	-d	Decompress"
//usage:     "\n	-t	Test file integrity"
//usage:	)
//usage:     "\n	-c	Write to stdout"
//usage:     "\n	-f	Force"
//usage:     "\n	-k	Keep input files"

#include "libbb.h"
#include "bb_archive.h"

#if CONFIG_BZIP2_SMALL >= 4
#define BZIP2_SPEED (9 - CONFIG_BZIP2_SMALL)
#else
#define BZIP2_SPEED 5
#endif

/* 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 BZIP2_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 "libarchive/bz/bzlib.h"

#include "libarchive/bz/bzlib_private.h"

#include "libarchive/bz/blocksort.c"
#include "libarchive/bz/bzlib.c"
#include "libarchive/bz/compress.c"
#include "libarchive/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 page aligned and thus (maybe) have one memcpy less
 * if kernel is clever enough.
 */
enum {
	IOBUF_SIZE = 8 * 1024
};

/* NB: compressStream() has to return -1 on errors, not die.
 * bbunpack() will correctly clean up in this case
 * (delete incomplete .bz2 file)
 */

/* Returns:
 * -1 on errors
 * total written bytes so far otherwise
 */
static
IF_DESKTOP(long long) int 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, rlen ? BZ_RUN : BZ_FINISH);
		if (ret != BZ_RUN_OK /* BZ_RUNning */
		 && ret != BZ_FINISH_OK /* BZ_FINISHing, but not done yet */
		 && ret != BZ_STREAM_END /* BZ_FINISHed */
		) {
			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) {
				if (n2 >= 0)
					errno = 0; /* prevent bogus error message */
				bb_simple_perror_msg(n2 >= 0 ? "short write" : bb_msg_write_error);
				return -1;
			}
		}

		if (ret == BZ_STREAM_END)
			break;
		if (rlen && strm->avail_in == 0)
			break;
	}
	return 0 IF_DESKTOP( + strm->total_out );
}

static
IF_DESKTOP(long long) int FAST_FUNC compressStream(transformer_state_t *xstate UNUSED_PARAM)
{
	IF_DESKTOP(long long) int total;
	unsigned opt, level;
	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);

	opt = option_mask32 >> (BBUNPK_OPTSTRLEN IF_FEATURE_BZIP2_DECOMPRESS(+ 2) + 2);
	/* skipped BBUNPK_OPTSTR, "dt" and "zs" bits */
	opt |= 0x100; /* if nothing else, assume -9 */
	level = 0;
	for (;;) {
		level++;
		if (opt & 1) break;
		opt >>= 1;
	}

	BZ2_bzCompressInit(strm, level);

	while (1) {
		count = full_read(STDIN_FILENO, rbuf, IOBUF_SIZE);
		if (count < 0) {
			bb_simple_perror_msg(bb_msg_read_error);
			total = -1;
			break;
		}
		/* if count == 0, bz_write finalizes compression */
		total = bz_write(strm, rbuf, count, wbuf);
		if (count == 0 || total < 0)
			break;
	}

	/* Can't be conditional on ENABLE_FEATURE_CLEAN_UP -
	 * we are called repeatedly
	 */
	BZ2_bzCompressEnd(strm);
	free(iobuf);

	return total;
}

int bzip2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int bzip2_main(int argc UNUSED_PARAM, char **argv)
{
	unsigned opt;

	/* standard bzip2 flags
	 * -d --decompress force decompression
	 * -z --compress force compression
	 * -k --keep     keep (don't delete) input files
	 * -f --force    overwrite existing output files
	 * -t --test     test compressed file integrity
	 * -c --stdout   output to standard out
	 * -q --quiet    suppress noncritical error messages
	 * -v --verbose  be verbose (a 2nd -v gives more)
	 * -s --small    use less memory (at most 2500k)
	 * -1 .. -9      set block size to 100k .. 900k
	 * --fast        alias for -1
	 * --best        alias for -9
	 */

	opt = getopt32(argv, "^"
		/* Must match BBUNPK_foo constants! */
		BBUNPK_OPTSTR IF_FEATURE_BZIP2_DECOMPRESS("dt") "zs123456789"
		"\0" "s2" /* -s means -2 (compatibility) */
	);
#if ENABLE_FEATURE_BZIP2_DECOMPRESS /* bunzip2_main may not be visible... */
	if (opt & (BBUNPK_OPT_DECOMPRESS|BBUNPK_OPT_TEST)) /* -d and/or -t */
		return bunzip2_main(argc, argv);
#else
	/* clear "decompress" and "test" bits (or bbunpack() can get confused) */
	/* in !BZIP2_DECOMPRESS config, these bits are -zs and are unused */
	option_mask32 = opt & ~(BBUNPK_OPT_DECOMPRESS|BBUNPK_OPT_TEST);
#endif

	argv += optind;
	return bbunpack(argv, compressStream, append_ext, "bz2");
}