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1 /* ----------------------------------------------------------------------- *
2  *
3  *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
4  *
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.
10  *
11  * ----------------------------------------------------------------------- */
12 
13 /*
14    This file is based in part on:
15 
16    precomp2.c -- example program: how to generate pre-compressed data
17 
18    This file is part of the LZO real-time data compression library.
19 
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
33    All Rights Reserved.
34 
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.
39 
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.
44 
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.
49 
50    Markus F.X.J. Oberhumer
51    <markus@oberhumer.com>
52    http://www.oberhumer.com/opensource/lzo/
53  */
54 
55 #include "lzo/lzoconf.h"
56 #include "lzo/lzo1x.h"
57 
58 LZO_EXTERN(int)
59 lzo1x_999_compress_internal(const lzo_bytep in, lzo_uint in_len,
60 			    lzo_bytep out, lzo_uintp out_len,
61 			    lzo_voidp wrkmem,
62 			    const lzo_bytep dict, lzo_uint dict_len,
63 			    lzo_callback_p cb,
64 			    int try_lazy,
65 			    lzo_uint good_length,
66 			    lzo_uint max_lazy,
67 			    lzo_uint nice_length,
68 			    lzo_uint max_chain, lzo_uint32 flags);
69 
70 LZO_EXTERN(int)
71 lzo1y_999_compress_internal(const lzo_bytep in, lzo_uint in_len,
72 			    lzo_bytep out, lzo_uintp out_len,
73 			    lzo_voidp wrkmem,
74 			    const lzo_bytep dict, lzo_uint dict_len,
75 			    lzo_callback_p cb,
76 			    int try_lazy,
77 			    lzo_uint good_length,
78 			    lzo_uint max_lazy,
79 			    lzo_uint nice_length,
80 			    lzo_uint max_chain, lzo_uint32 flags);
81 
82 #define PARANOID 1
83 
84 #include <assert.h>
85 #include <ctype.h>
86 #include <errno.h>
87 #include <inttypes.h>
88 #include <stdarg.h>
89 #include <stddef.h>
90 #include <stdlib.h>
91 #include <stdio.h>
92 #include <string.h>
93 #include <time.h>
94 
95 #ifdef __GNUC__
96 # define noreturn void __attribute__((noreturn))
97 #else
98 # define noreturn void
99 #endif
100 
101 struct prefix {
102     uint32_t pfx_start;
103     uint32_t pfx_compressed;
104     uint32_t pfx_cdatalen;
105     uint32_t pfx_checksum;
106     uint32_t pfx_maxlma;
107 };
108 
get_32(const uint32_t * p)109 static inline uint32_t get_32(const uint32_t * p)
110 {
111 #if defined(__i386__) || defined(__x86_64__)
112     /* Littleendian and unaligned-capable */
113     return *p;
114 #else
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);
118 #endif
119 }
120 
set_32(uint32_t * p,uint32_t v)121 static inline void set_32(uint32_t * p, uint32_t v)
122 {
123 #if defined(__i386__) || defined(__x86_64__)
124     /* Littleendian and unaligned-capable */
125     *p = v;
126 #else
127     uint8_t *pp = (uint8_t *) p;
128     pp[0] = (v & 0xff);
129     pp[1] = ((v >> 8) & 0xff);
130     pp[2] = ((v >> 16) & 0xff);
131     pp[3] = ((v >> 24) & 0xff);
132 #endif
133 }
134 
135 const char *progname = NULL;
136 const char *in_name  = NULL;
137 const char *out_name = NULL;
138 
error(const char * fmt,...)139 static noreturn error(const char *fmt, ...)
140 {
141     va_list ap;
142 
143     va_start(ap, fmt);
144     fprintf(stderr, "%s: ", progname);
145     if (in_name)
146 	fprintf(stderr, "%s: ", in_name);
147     vfprintf(stderr, fmt, ap);
148     fputc('\n', stderr);
149     va_end(ap);
150 
151     exit(1);
152 }
153 
xzalloc(size_t n)154 static void *xzalloc(size_t n)
155 {
156     void *p = calloc(n, 1);
157     if (!p)
158 	error("out of memory");
159     return p;
160 }
161 
162 /*************************************************************************
163 //
164 **************************************************************************/
165 
main(int argc,char * argv[])166 int main(int argc, char *argv[])
167 {
168     int r;
169     int lazy;
170     const int max_try_lazy = 5;
171     const lzo_uint big = 65536L;	/* can result in very slow compression */
172     const lzo_uint32 flags = 0x1;
173 
174     lzo_bytep in;
175     lzo_bytep infile;
176     lzo_uint in_len, infile_len, start, offset, soff;
177 
178     lzo_bytep out;
179     lzo_uint out_bufsize;
180     lzo_uint out_len = 0;
181     lzo_uint outfile_len;
182 
183     lzo_bytep test;
184 
185     lzo_byte wrkmem[LZO1X_999_MEM_COMPRESS];
186 
187     lzo_uint best_len;
188     int best_lazy = -1;
189 
190     lzo_uint orig_len;
191     lzo_uint32 uncompressed_checksum;
192     lzo_uint32 compressed_checksum;
193 
194     FILE *f;
195     long l;
196 
197     struct prefix *prefix;
198 
199     progname = argv[0];
200     if (argc != 3) {
201 	fprintf(stderr, "Usage: %s file output-file\n", progname);
202 	exit(1);
203     }
204     in_name = argv[1];
205     if (argc > 2)
206 	out_name = argv[2];
207 
208 /*
209  * Step 1: initialize the LZO library
210  */
211     if (lzo_init() != LZO_E_OK)
212 	error("internal error - lzo_init() failed!");
213 
214 /*
215  * Step 3: open the input file
216  */
217     f = fopen(in_name, "rb");
218     if (!f)
219 	error("cannot open file: %s", strerror(errno));
220 
221     fseek(f, 0, SEEK_END);
222     l = ftell(f);
223     fseek(f, 0, SEEK_SET);
224     if (l <= 0) {
225 	error("empty file", progname, in_name);
226 	fclose(f);
227 	exit(1);
228     }
229     infile_len = (lzo_uint) l;
230     out_bufsize = infile_len + infile_len / 16 + 64 + 3 + 2048;
231 
232 /*
233  * Step 4: allocate compression buffers and read the file
234  */
235     infile = xzalloc(infile_len);
236     out = xzalloc(out_bufsize);
237     infile_len = fread(infile, 1, infile_len, f);
238     fclose(f);
239 
240 /*
241  * Select the portion which is for compression...
242  */
243     prefix = (struct prefix *)infile;
244     start = get_32(&prefix->pfx_start);
245     offset = get_32(&prefix->pfx_compressed);
246     in = infile + offset;
247     in_len = infile_len - offset;
248     best_len = in_len;
249 
250 /*
251  * Step 5: compute a checksum of the uncompressed data
252  */
253     uncompressed_checksum = lzo_adler32(0, NULL, 0);
254     uncompressed_checksum = lzo_adler32(uncompressed_checksum, in, in_len);
255 
256 /*
257  * Step 6a: compress from `in' to `out' with LZO1X-999
258  */
259     for (lazy = 0; lazy <= max_try_lazy; lazy++) {
260 	out_len = out_bufsize;
261 	r = lzo1x_999_compress_internal(in, in_len, out, &out_len, wrkmem,
262 					NULL, 0, 0,
263 					lazy, big, big, big, big, flags);
264 	if (r != LZO_E_OK)
265 	    /* this should NEVER happen */
266 	    error("internal error - compression failed: %d", r);
267 
268 	if (out_len < best_len) {
269 	    best_len = out_len;
270 	    best_lazy = lazy;
271 	}
272     }
273 
274 /*
275  * Step 7: check if compressible
276  */
277     if (best_len >= in_len) {
278 	fprintf(stderr, "%s: %s: this file contains incompressible data.",
279 		progname, in_name);
280 	/* do it anyway */
281     }
282 
283 /*
284  * Step 8: compress data again using the best compressor found
285  */
286     out_len = out_bufsize;
287     r = lzo1x_999_compress_internal(in, in_len, out, &out_len, wrkmem,
288 				    NULL, 0, 0,
289 				    best_lazy, big, big, big, big, flags);
290     assert(r == LZO_E_OK);
291     assert(out_len == best_len);
292 
293 /*
294  * Step 9: optimize compressed data (compressed data is in `out' buffer)
295  */
296 #if 1
297     /* Optimization does not require any data in the buffer that will
298      * hold the uncompressed data. To prove this, we clear the buffer.
299      */
300     memset(in, 0, in_len);
301 #endif
302 
303     orig_len = in_len;
304     r = lzo1x_optimize(out, out_len, in, &orig_len, NULL);
305     if (r != LZO_E_OK || orig_len != in_len) {
306 	/* this should NEVER happen */
307 	error("internal error - optimization failed: %d", r);
308     }
309 
310 /*
311  * Step 10: compute a checksum of the compressed data
312  */
313     compressed_checksum = lzo_adler32(0, NULL, 0);
314     compressed_checksum = lzo_adler32(compressed_checksum, out, out_len);
315 
316 /*
317  * Step 11: write compressed data to a file
318  */
319     /* Make sure we have up to 2048 bytes of zero after the output */
320     memset(out + out_len, 0, 2048);
321 
322     outfile_len = out_len;
323 
324     soff = get_32(&prefix->pfx_cdatalen);
325     set_32((uint32_t *) (infile + soff), out_len);
326 
327     soff = get_32(&prefix->pfx_checksum);
328     if (soff) {
329 	/* ISOLINUX padding and checksumming */
330 	uint32_t csum = 0;
331 	unsigned int ptr;
332 	outfile_len =
333 	    ((offset - start + out_len + 2047) & ~2047) - (offset - start);
334 	for (ptr = 64; ptr < offset; ptr += 4)
335 	    csum += get_32((uint32_t *) (infile + ptr));
336 	for (ptr = 0; ptr < outfile_len; ptr += 4)
337 	    csum += get_32((uint32_t *) (out + ptr));
338 
339 	set_32((uint32_t *) (infile + soff), offset - start + outfile_len);
340 	set_32((uint32_t *) (infile + soff + 4), csum);
341     }
342 
343 	/*
344     if (offset+outfile_len > get_32(&prefix->pfx_maxlma))
345 	error("output too big (%lu, max %lu)",
346 	      (unsigned long)offset+outfile_len,
347 	      (unsigned long)get_32(&prefix->pfx_maxlma));
348 	      */
349 
350     f = fopen(out_name, "wb");
351     if (!f)
352 	error("cannot open output file %s: %s", out_name, strerror(errno));
353 
354     if (fwrite(infile + start, 1, offset - start, f) != offset - start ||
355 	fwrite(out, 1, outfile_len, f) != outfile_len || fclose(f))
356 	error("write error");
357 
358 /*
359  * Step 12: verify decompression
360  */
361 #ifdef PARANOID
362     orig_len = in_len * 2;
363     test = xzalloc(orig_len);
364     r = lzo1x_decompress_safe(out, out_len, test, &orig_len, NULL);
365 
366     if (r != LZO_E_OK || orig_len != in_len) {
367 	/* this should NEVER happen */
368 	error("internal error - decompression failed: %d", r);
369     }
370 
371     if (memcmp(test, in, in_len)) {
372 	/* this should NEVER happen */
373 	error("internal error - decompression data error");
374     }
375 
376     /* Now you could also verify decompression under similar conditions as in
377      * your application, e.g. overlapping assembler decompression etc.
378      */
379 
380     free(test);
381 #endif
382 
383     free(infile);
384     free(out);
385 
386     return 0;
387 }
388