1 /* ----------------------------------------------------------------------- *
3 * Copyright 2009 Intel Corporation; author: H. Peter Anvin
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
8 * Boston MA 02110-1301, USA; either version 2 of the License, or
9 * (at your option) any later version; incorporated herein by reference.
11 * ----------------------------------------------------------------------- */
14 This file is based in part on:
16 precomp2.c -- example program: how to generate pre-compressed data
18 This file is part of the LZO real-time data compression library.
20 Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
21 Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
22 Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
23 Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
24 Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
25 Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
26 Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
27 Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
28 Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
29 Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
30 Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
31 Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
32 Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer
35 The LZO library is free software; you can redistribute it and/or
36 modify it under the terms of the GNU General Public License as
37 published by the Free Software Foundation; either version 2 of
38 the License, or (at your option) any later version.
40 The LZO library is distributed in the hope that it will be useful,
41 but WITHOUT ANY WARRANTY; without even the implied warranty of
42 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
43 GNU General Public License for more details.
45 You should have received a copy of the GNU General Public License
46 along with the LZO library; see the file COPYING.
47 If not, write to the Free Software Foundation, Inc.,
48 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
50 Markus F.X.J. Oberhumer
51 <markus@oberhumer.com>
52 http://www.oberhumer.com/opensource/lzo/
55 #include "lzo/lzoconf.h"
56 #include "lzo/lzo1x.h"
59 lzo1x_999_compress_internal(const lzo_bytep in, lzo_uint in_len,
60 lzo_bytep out, lzo_uintp out_len,
62 const lzo_bytep dict, lzo_uint dict_len,
68 lzo_uint max_chain, lzo_uint32 flags);
71 lzo1y_999_compress_internal(const lzo_bytep in, lzo_uint in_len,
72 lzo_bytep out, lzo_uintp out_len,
74 const lzo_bytep dict, lzo_uint dict_len,
80 lzo_uint max_chain, lzo_uint32 flags);
96 # define noreturn void __attribute__((noreturn))
98 # define noreturn void
103 uint32_t pfx_compressed;
104 uint32_t pfx_cdatalen;
105 uint32_t pfx_checksum;
109 static inline uint32_t get_32(const uint32_t * p)
111 #if defined(__i386__) || defined(__x86_64__)
112 /* Littleendian and unaligned-capable */
115 const uint8_t *pp = (const uint8_t *)p;
116 return (uint32_t) pp[0] + ((uint32_t) pp[1] << 8) +
117 ((uint32_t) pp[2] << 16) + ((uint32_t) pp[3] << 24);
121 static inline void set_32(uint32_t * p, uint32_t v)
123 #if defined(__i386__) || defined(__x86_64__)
124 /* Littleendian and unaligned-capable */
127 uint8_t *pp = (uint8_t *) p;
129 pp[1] = ((v >> 8) & 0xff);
130 pp[2] = ((v >> 16) & 0xff);
131 pp[3] = ((v >> 24) & 0xff);
135 const char *progname = NULL;
136 const char *in_name = NULL;
137 const char *out_name = NULL;
139 static noreturn error(const char *fmt, ...)
144 fprintf(stderr, "%s: ", progname);
146 fprintf(stderr, "%s: ", in_name);
147 vfprintf(stderr, fmt, ap);
153 static void *xzalloc(size_t n)
155 void *p = calloc(n, 1);
157 error("out of memory");
161 /*************************************************************************
163 **************************************************************************/
165 int main(int argc, char *argv[])
169 const int max_try_lazy = 5;
170 const lzo_uint big = 65536L; /* can result in very slow compression */
171 const lzo_uint32 flags = 0x1;
175 lzo_uint in_len, infile_len, start, offset, soff;
178 lzo_uint out_bufsize;
179 lzo_uint out_len = 0;
180 lzo_uint outfile_len;
184 lzo_byte wrkmem[LZO1X_999_MEM_COMPRESS];
190 lzo_uint32 uncompressed_checksum;
191 lzo_uint32 compressed_checksum;
196 struct prefix *prefix;
200 printf("Usage: %s file output-file\n", progname);
208 * Step 1: initialize the LZO library
210 if (lzo_init() != LZO_E_OK)
211 error("internal error - lzo_init() failed!\n");
214 * Step 3: open the input file
216 f = fopen(in_name, "rb");
218 error("cannot open file: %s\n", strerror(errno));
220 fseek(f, 0, SEEK_END);
222 fseek(f, 0, SEEK_SET);
224 error("empty file\n", progname, in_name);
228 infile_len = (lzo_uint) l;
229 out_bufsize = infile_len + infile_len / 16 + 64 + 3 + 2048;
232 * Step 4: allocate compression buffers and read the file
234 infile = xzalloc(infile_len);
235 out = xzalloc(out_bufsize);
236 infile_len = fread(infile, 1, infile_len, f);
240 * Select the portion which is for compression...
242 prefix = (struct prefix *)infile;
243 start = get_32(&prefix->pfx_start);
244 offset = get_32(&prefix->pfx_compressed);
245 in = infile + offset;
246 in_len = infile_len - offset;
250 * Step 5: compute a checksum of the uncompressed data
252 uncompressed_checksum = lzo_adler32(0, NULL, 0);
253 uncompressed_checksum = lzo_adler32(uncompressed_checksum, in, in_len);
256 * Step 6a: compress from `in' to `out' with LZO1X-999
258 for (lazy = 0; lazy <= max_try_lazy; lazy++) {
259 out_len = out_bufsize;
260 r = lzo1x_999_compress_internal(in, in_len, out, &out_len, wrkmem,
262 lazy, big, big, big, big, flags);
264 /* this should NEVER happen */
265 error("internal error - compression failed: %d\n", r);
267 if (out_len < best_len) {
274 * Step 7: check if compressible
276 if (best_len >= in_len) {
277 fprintf(stderr, "%s: %s: this file contains incompressible data.\n",
283 * Step 8: compress data again using the best compressor found
285 out_len = out_bufsize;
286 r = lzo1x_999_compress_internal(in, in_len, out, &out_len, wrkmem,
288 best_lazy, big, big, big, big, flags);
289 assert(r == LZO_E_OK);
290 assert(out_len == best_len);
293 * Step 9: optimize compressed data (compressed data is in `out' buffer)
296 /* Optimization does not require any data in the buffer that will
297 * hold the uncompressed data. To prove this, we clear the buffer.
299 memset(in, 0, in_len);
303 r = lzo1x_optimize(out, out_len, in, &orig_len, NULL);
304 if (r != LZO_E_OK || orig_len != in_len) {
305 /* this should NEVER happen */
306 error("internal error - optimization failed: %d\n", r);
310 * Step 10: compute a checksum of the compressed data
312 compressed_checksum = lzo_adler32(0, NULL, 0);
313 compressed_checksum = lzo_adler32(compressed_checksum, out, out_len);
316 * Step 11: write compressed data to a file
318 /* Make sure we have up to 2048 bytes of zero after the output */
319 memset(out + out_len, 0, 2048);
321 outfile_len = out_len;
323 soff = get_32(&prefix->pfx_cdatalen);
324 set_32((uint32_t *) (infile + soff), out_len);
326 soff = get_32(&prefix->pfx_checksum);
328 /* ISOLINUX padding and checksumming */
332 ((offset - start + out_len + 2047) & ~2047) - (offset - start);
333 for (ptr = 64; ptr < offset; ptr += 4)
334 csum += get_32((uint32_t *) (infile + ptr));
335 for (ptr = 0; ptr < outfile_len; ptr += 4)
336 csum += get_32((uint32_t *) (out + ptr));
338 set_32((uint32_t *) (infile + soff), offset - start + outfile_len);
339 set_32((uint32_t *) (infile + soff + 4), csum);
342 if (offset+outfile_len > get_32(&prefix->pfx_maxlma))
343 error("output too big (%lu, max %lu)\n",
344 (unsigned long)offset+outfile_len,
345 (unsigned long)get_32(&prefix->pfx_maxlma));
347 f = fopen(out_name, "wb");
349 error("cannot open output file %s: %s\n", out_name, strerror(errno));
351 if (fwrite(infile + start, 1, offset - start, f) != offset - start ||
352 fwrite(out, 1, outfile_len, f) != outfile_len || fclose(f))
353 error("write error\n");
356 * Step 12: verify decompression
359 orig_len = in_len * 2;
360 test = xzalloc(orig_len);
361 r = lzo1x_decompress_safe(out, out_len, test, &orig_len, NULL);
363 if (r != LZO_E_OK || orig_len != in_len) {
364 /* this should NEVER happen */
365 error("internal error - decompression failed: %d\n", r);
368 if (memcmp(test, in, in_len)) {
369 /* this should NEVER happen */
370 error("internal error - decompression data error\n");
373 /* Now you could also verify decompression under similar conditions as in
374 * your application, e.g. overlapping assembler decompression etc.