1/* precomp2.c -- example program: how to generate pre-compressed data 2 3 This file is part of the LZO real-time data compression library. 4 5 Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer 6 Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer 7 Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer 8 Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer 9 Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer 10 Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer 11 Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer 12 Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer 13 Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer 14 Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer 15 Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer 16 Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer 17 Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer 18 All Rights Reserved. 19 20 The LZO library is free software; you can redistribute it and/or 21 modify it under the terms of the GNU General Public License as 22 published by the Free Software Foundation; either version 2 of 23 the License, or (at your option) any later version. 24 25 The LZO library is distributed in the hope that it will be useful, 26 but WITHOUT ANY WARRANTY; without even the implied warranty of 27 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 28 GNU General Public License for more details. 29 30 You should have received a copy of the GNU General Public License 31 along with the LZO library; see the file COPYING. 32 If not, write to the Free Software Foundation, Inc., 33 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 34 35 Markus F.X.J. Oberhumer 36 <markus@oberhumer.com> 37 http://www.oberhumer.com/opensource/lzo/ 38 */ 39 40 41/************************************************************************* 42// This program shows how to generate pre-compressed data. 43// 44// Please study precomp.c first. 45// 46// We will be trying LZO1X-999 and LZO1Y-999, and we will be trying 47// various parameters using the internal interface to squeeze out 48// a little bit of extra compression. 49// 50// NOTE: this program can be quite slow for highly redundant files 51**************************************************************************/ 52 53#include "lzo/lzoconf.h" 54#include "lzo/lzo1x.h" 55#include "lzo/lzo1y.h" 56 57LZO_EXTERN(int) 58lzo1x_999_compress_internal ( const lzo_bytep in , lzo_uint in_len, 59 lzo_bytep out, lzo_uintp out_len, 60 lzo_voidp wrkmem, 61 const lzo_bytep dict, lzo_uint dict_len, 62 lzo_callback_p cb, 63 int try_lazy, 64 lzo_uint good_length, 65 lzo_uint max_lazy, 66 lzo_uint nice_length, 67 lzo_uint max_chain, 68 lzo_uint32 flags ); 69 70LZO_EXTERN(int) 71lzo1y_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, 81 lzo_uint32 flags ); 82 83#define USE_LZO1X 1 84#define USE_LZO1Y 1 85 86#define PARANOID 1 87 88 89/* portability layer */ 90#define WANT_LZO_MALLOC 1 91#define WANT_LZO_FREAD 1 92#define WANT_LZO_WILDARGV 1 93#include "examples/portab.h" 94 95 96/************************************************************************* 97// 98**************************************************************************/ 99 100int __lzo_cdecl_main main(int argc, char *argv[]) 101{ 102 int r; 103 int lazy; 104 const int max_try_lazy = 5; 105 const lzo_uint big = 65536L; /* can result in very slow compression */ 106 const lzo_uint32 flags = 0x1; 107 108 lzo_bytep in; 109 lzo_uint in_len; 110 111 lzo_bytep out; 112 lzo_uint out_bufsize; 113 lzo_uint out_len = 0; 114 115 lzo_bytep wrkmem; 116 lzo_uint wrk_len; 117 118 lzo_uint best_len; 119 int best_compress = -1; 120 int best_lazy = -1; 121 122 lzo_uint orig_len; 123 lzo_uint32 uncompressed_checksum; 124 lzo_uint32 compressed_checksum; 125 126 FILE *f; 127 const char *progname = NULL; 128 const char *in_name = NULL; 129 const char *out_name = NULL; 130 long l; 131 132 133 lzo_wildargv(&argc, &argv); 134 135 printf("\nLZO real-time data compression library (v%s, %s).\n", 136 lzo_version_string(), lzo_version_date()); 137 printf("Copyright (C) 1996-2008 Markus Franz Xaver Johannes Oberhumer\nAll Rights Reserved.\n\n"); 138 139 progname = argv[0]; 140 if (argc < 2 || argc > 3) 141 { 142 printf("usage: %s file [output-file]\n", progname); 143 exit(1); 144 } 145 in_name = argv[1]; 146 if (argc > 2) out_name = argv[2]; 147 148/* 149 * Step 1: initialize the LZO library 150 */ 151 if (lzo_init() != LZO_E_OK) 152 { 153 printf("internal error - lzo_init() failed !!!\n"); 154 printf("(this usually indicates a compiler bug - try recompiling\nwithout optimizations, and enable `-DLZO_DEBUG' for diagnostics)\n"); 155 exit(1); 156 } 157 158/* 159 * Step 2: allocate the work-memory 160 */ 161 wrk_len = 1; 162#ifdef USE_LZO1X 163 if (wrk_len < LZO1X_999_MEM_COMPRESS) 164 wrk_len = LZO1X_999_MEM_COMPRESS; 165#endif 166#ifdef USE_LZO1Y 167 if (wrk_len < LZO1Y_999_MEM_COMPRESS) 168 wrk_len = LZO1Y_999_MEM_COMPRESS; 169#endif 170 wrkmem = (lzo_bytep) lzo_malloc(wrk_len); 171 if (wrkmem == NULL) 172 { 173 printf("%s: out of memory\n", progname); 174 exit(1); 175 } 176 177/* 178 * Step 3: open the input file 179 */ 180 f = fopen(in_name,"rb"); 181 if (f == NULL) 182 { 183 printf("%s: cannot open file %s\n", progname, in_name); 184 exit(1); 185 } 186 fseek(f,0,SEEK_END); 187 l = ftell(f); 188 fseek(f,0,SEEK_SET); 189 if (l <= 0) 190 { 191 printf("%s: %s: empty file\n", progname, in_name); 192 fclose(f); 193 exit(1); 194 } 195 in_len = (lzo_uint) l; 196 out_bufsize = in_len + in_len / 16 + 64 + 3; 197 best_len = in_len; 198 199/* 200 * Step 4: allocate compression buffers and read the file 201 */ 202 in = (lzo_bytep) lzo_malloc(in_len); 203 out = (lzo_bytep) lzo_malloc(out_bufsize); 204 if (in == NULL || out == NULL) 205 { 206 printf("%s: out of memory\n", progname); 207 exit(1); 208 } 209 in_len = (lzo_uint) lzo_fread(f,in,in_len); 210 printf("%s: loaded file %s: %ld bytes\n", progname, in_name, (long) in_len); 211 fclose(f); 212 213/* 214 * Step 5: compute a checksum of the uncompressed data 215 */ 216 uncompressed_checksum = lzo_adler32(0,NULL,0); 217 uncompressed_checksum = lzo_adler32(uncompressed_checksum,in,in_len); 218 219/* 220 * Step 6a: compress from `in' to `out' with LZO1X-999 221 */ 222#ifdef USE_LZO1X 223 for (lazy = 0; lazy <= max_try_lazy; lazy++) 224 { 225 out_len = out_bufsize; 226 r = lzo1x_999_compress_internal(in,in_len,out,&out_len,wrkmem, 227 NULL, 0, 0, 228 lazy, big, big, big, big, flags); 229 if (r != LZO_E_OK) 230 { 231 /* this should NEVER happen */ 232 printf("internal error - compression failed: %d\n", r); 233 exit(1); 234 } 235 printf("LZO1X-999: lazy =%2d: %8lu -> %8lu\n", 236 lazy, (unsigned long) in_len, (unsigned long) out_len); 237 if (out_len < best_len) 238 { 239 best_len = out_len; 240 best_lazy = lazy; 241 best_compress = 1; /* LZO1X-999 */ 242 } 243 } 244#endif /* USE_LZO1X */ 245 246/* 247 * Step 6b: compress from `in' to `out' with LZO1Y-999 248 */ 249#ifdef USE_LZO1Y 250 for (lazy = 0; lazy <= max_try_lazy; lazy++) 251 { 252 out_len = out_bufsize; 253 r = lzo1y_999_compress_internal(in,in_len,out,&out_len,wrkmem, 254 NULL, 0, 0, 255 lazy, big, big, big, big, flags); 256 if (r != LZO_E_OK) 257 { 258 /* this should NEVER happen */ 259 printf("internal error - compression failed: %d\n", r); 260 exit(1); 261 } 262 printf("LZO1Y-999: lazy =%2d: %8lu -> %8lu\n", 263 lazy, (unsigned long) in_len, (unsigned long) out_len); 264 if (out_len < best_len) 265 { 266 best_len = out_len; 267 best_lazy = lazy; 268 best_compress = 2; /* LZO1Y-999 */ 269 } 270 } 271#endif /* USE_LZO1Y */ 272 273/* 274 * Step 7: check if compressible 275 */ 276 if (best_len >= in_len) 277 { 278 printf("This file contains incompressible data.\n"); 279 return 0; 280 } 281 282/* 283 * Step 8: compress data again using the best compressor found 284 */ 285 out_len = out_bufsize; 286 if (best_compress == 1) 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 else if (best_compress == 2) 291 r = lzo1y_999_compress_internal(in,in_len,out,&out_len,wrkmem, 292 NULL, 0, 0, 293 best_lazy, big, big, big, big, flags); 294 else 295 r = -100; 296 assert(r == LZO_E_OK); 297 assert(out_len == best_len); 298 299/* 300 * Step 9: optimize compressed data (compressed data is in `out' buffer) 301 */ 302#if 1 303 /* Optimization does not require any data in the buffer that will 304 * hold the uncompressed data. To prove this, we clear the buffer. 305 */ 306 lzo_memset(in,0,in_len); 307#endif 308 309 orig_len = in_len; 310 r = -100; 311#ifdef USE_LZO1X 312 if (best_compress == 1) 313 r = lzo1x_optimize(out,out_len,in,&orig_len,NULL); 314#endif 315#ifdef USE_LZO1Y 316 if (best_compress == 2) 317 r = lzo1y_optimize(out,out_len,in,&orig_len,NULL); 318#endif 319 if (r != LZO_E_OK || orig_len != in_len) 320 { 321 /* this should NEVER happen */ 322 printf("internal error - optimization failed: %d\n", r); 323 exit(1); 324 } 325 326/* 327 * Step 10: compute a checksum of the compressed data 328 */ 329 compressed_checksum = lzo_adler32(0,NULL,0); 330 compressed_checksum = lzo_adler32(compressed_checksum,out,out_len); 331 332/* 333 * Step 11: write compressed data to a file 334 */ 335 printf("%s: %s: %ld -> %ld, checksum 0x%08lx 0x%08lx\n", 336 progname, in_name, (long) in_len, (long) out_len, 337 (long) uncompressed_checksum, (long) compressed_checksum); 338 339 if (out_name && out_name[0]) 340 { 341 printf("%s: writing to file %s\n", progname, out_name); 342 f = fopen(out_name,"wb"); 343 if (f == NULL) 344 { 345 printf("%s: cannot open output file %s\n", progname, out_name); 346 exit(1); 347 } 348 if (lzo_fwrite(f,out,out_len) != out_len || fclose(f) != 0) 349 { 350 printf("%s: write error !!\n", progname); 351 exit(1); 352 } 353 } 354 355/* 356 * Step 12: verify decompression 357 */ 358#ifdef PARANOID 359 lzo_memset(in,0,in_len); /* paranoia - clear output buffer */ 360 orig_len = in_len; 361 r = -100; 362#ifdef USE_LZO1X 363 if (best_compress == 1) 364 r = lzo1x_decompress_safe(out,out_len,in,&orig_len,NULL); 365#endif 366#ifdef USE_LZO1Y 367 if (best_compress == 2) 368 r = lzo1y_decompress_safe(out,out_len,in,&orig_len,NULL); 369#endif 370 if (r != LZO_E_OK || orig_len != in_len) 371 { 372 /* this should NEVER happen */ 373 printf("internal error - decompression failed: %d\n", r); 374 exit(1); 375 } 376 if (uncompressed_checksum != lzo_adler32(lzo_adler32(0,NULL,0),in,in_len)) 377 { 378 /* this should NEVER happen */ 379 printf("internal error - decompression data error\n"); 380 exit(1); 381 } 382 /* Now you could also verify decompression under similar conditions as in 383 * your application, e.g. overlapping assembler decompression etc. 384 */ 385#endif 386 387 lzo_free(in); 388 lzo_free(out); 389 lzo_free(wrkmem); 390 391 return 0; 392} 393 394/* 395vi:ts=4:et 396*/ 397 398