1 /*- 2 * Copyright (c) 2008 Joerg Sonnenberger 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 /*- 27 * Copyright (c) 1985, 1986, 1992, 1993 28 * The Regents of the University of California. All rights reserved. 29 * 30 * This code is derived from software contributed to Berkeley by 31 * Diomidis Spinellis and James A. Woods, derived from original 32 * work by Spencer Thomas and Joseph Orost. 33 * 34 * Redistribution and use in source and binary forms, with or without 35 * modification, are permitted provided that the following conditions 36 * are met: 37 * 1. Redistributions of source code must retain the above copyright 38 * notice, this list of conditions and the following disclaimer. 39 * 2. Redistributions in binary form must reproduce the above copyright 40 * notice, this list of conditions and the following disclaimer in the 41 * documentation and/or other materials provided with the distribution. 42 * 3. Neither the name of the University nor the names of its contributors 43 * may be used to endorse or promote products derived from this software 44 * without specific prior written permission. 45 * 46 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 47 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 48 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 49 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 50 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 51 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 52 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 53 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 54 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 55 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 56 * SUCH DAMAGE. 57 */ 58 59 #include "archive_platform.h" 60 61 __FBSDID("$FreeBSD: head/lib/libarchive/archive_write_set_compression_compress.c 201111 2009-12-28 03:33:05Z kientzle $"); 62 63 #ifdef HAVE_ERRNO_H 64 #include <errno.h> 65 #endif 66 #ifdef HAVE_STDLIB_H 67 #include <stdlib.h> 68 #endif 69 #ifdef HAVE_STRING_H 70 #include <string.h> 71 #endif 72 73 #include "archive.h" 74 #include "archive_private.h" 75 #include "archive_write_private.h" 76 77 #define HSIZE 69001 /* 95% occupancy */ 78 #define HSHIFT 8 /* 8 - trunc(log2(HSIZE / 65536)) */ 79 #define CHECK_GAP 10000 /* Ratio check interval. */ 80 81 #define MAXCODE(bits) ((1 << (bits)) - 1) 82 83 /* 84 * the next two codes should not be changed lightly, as they must not 85 * lie within the contiguous general code space. 86 */ 87 #define FIRST 257 /* First free entry. */ 88 #define CLEAR 256 /* Table clear output code. */ 89 90 struct private_data { 91 int64_t in_count, out_count, checkpoint; 92 93 int code_len; /* Number of bits/code. */ 94 int cur_maxcode; /* Maximum code, given n_bits. */ 95 int max_maxcode; /* Should NEVER generate this code. */ 96 int hashtab [HSIZE]; 97 unsigned short codetab [HSIZE]; 98 int first_free; /* First unused entry. */ 99 int compress_ratio; 100 101 int cur_code, cur_fcode; 102 103 int bit_offset; 104 unsigned char bit_buf; 105 106 unsigned char *compressed; 107 size_t compressed_buffer_size; 108 size_t compressed_offset; 109 }; 110 111 static int archive_compressor_compress_open(struct archive_write_filter *); 112 static int archive_compressor_compress_write(struct archive_write_filter *, 113 const void *, size_t); 114 static int archive_compressor_compress_close(struct archive_write_filter *); 115 static int archive_compressor_compress_free(struct archive_write_filter *); 116 117 #if ARCHIVE_VERSION_NUMBER < 4000000 118 int 119 archive_write_set_compression_compress(struct archive *a) 120 { 121 __archive_write_filters_free(a); 122 return (archive_write_add_filter_compress(a)); 123 } 124 #endif 125 126 /* 127 * Add a compress filter to this write handle. 128 */ 129 int 130 archive_write_add_filter_compress(struct archive *_a) 131 { 132 struct archive_write *a = (struct archive_write *)_a; 133 struct archive_write_filter *f = __archive_write_allocate_filter(_a); 134 135 archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC, 136 ARCHIVE_STATE_NEW, "archive_write_add_filter_compress"); 137 f->open = &archive_compressor_compress_open; 138 f->code = ARCHIVE_COMPRESSION_COMPRESS; 139 f->name = "compress"; 140 return (ARCHIVE_OK); 141 } 142 143 /* 144 * Setup callback. 145 */ 146 static int 147 archive_compressor_compress_open(struct archive_write_filter *f) 148 { 149 int ret; 150 struct private_data *state; 151 152 f->code = ARCHIVE_COMPRESSION_COMPRESS; 153 f->name = "compress"; 154 155 ret = __archive_write_open_filter(f->next_filter); 156 if (ret != ARCHIVE_OK) 157 return (ret); 158 159 state = (struct private_data *)calloc(1, sizeof(*state)); 160 if (state == NULL) { 161 archive_set_error(f->archive, ENOMEM, 162 "Can't allocate data for compression"); 163 return (ARCHIVE_FATAL); 164 } 165 166 state->compressed_buffer_size = 65536; 167 state->compressed = malloc(state->compressed_buffer_size); 168 169 if (state->compressed == NULL) { 170 archive_set_error(f->archive, ENOMEM, 171 "Can't allocate data for compression buffer"); 172 free(state); 173 return (ARCHIVE_FATAL); 174 } 175 176 f->write = archive_compressor_compress_write; 177 f->close = archive_compressor_compress_close; 178 f->free = archive_compressor_compress_free; 179 180 state->max_maxcode = 0x10000; /* Should NEVER generate this code. */ 181 state->in_count = 0; /* Length of input. */ 182 state->bit_buf = 0; 183 state->bit_offset = 0; 184 state->out_count = 3; /* Includes 3-byte header mojo. */ 185 state->compress_ratio = 0; 186 state->checkpoint = CHECK_GAP; 187 state->code_len = 9; 188 state->cur_maxcode = MAXCODE(state->code_len); 189 state->first_free = FIRST; 190 191 memset(state->hashtab, 0xff, sizeof(state->hashtab)); 192 193 /* Prime output buffer with a gzip header. */ 194 state->compressed[0] = 0x1f; /* Compress */ 195 state->compressed[1] = 0x9d; 196 state->compressed[2] = 0x90; /* Block mode, 16bit max */ 197 state->compressed_offset = 3; 198 199 f->data = state; 200 return (0); 201 } 202 203 /*- 204 * Output the given code. 205 * Inputs: 206 * code: A n_bits-bit integer. If == -1, then EOF. This assumes 207 * that n_bits <= (long)wordsize - 1. 208 * Outputs: 209 * Outputs code to the file. 210 * Assumptions: 211 * Chars are 8 bits long. 212 * Algorithm: 213 * Maintain a BITS character long buffer (so that 8 codes will 214 * fit in it exactly). Use the VAX insv instruction to insert each 215 * code in turn. When the buffer fills up empty it and start over. 216 */ 217 218 static const unsigned char rmask[9] = 219 {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff}; 220 221 static int 222 output_byte(struct archive_write_filter *f, unsigned char c) 223 { 224 struct private_data *state = f->data; 225 226 state->compressed[state->compressed_offset++] = c; 227 ++state->out_count; 228 229 if (state->compressed_buffer_size == state->compressed_offset) { 230 int ret = __archive_write_filter(f->next_filter, 231 state->compressed, state->compressed_buffer_size); 232 if (ret != ARCHIVE_OK) 233 return ARCHIVE_FATAL; 234 state->compressed_offset = 0; 235 } 236 237 return ARCHIVE_OK; 238 } 239 240 static int 241 output_code(struct archive_write_filter *f, int ocode) 242 { 243 struct private_data *state = f->data; 244 int bits, ret, clear_flg, bit_offset; 245 246 clear_flg = ocode == CLEAR; 247 248 /* 249 * Since ocode is always >= 8 bits, only need to mask the first 250 * hunk on the left. 251 */ 252 bit_offset = state->bit_offset % 8; 253 state->bit_buf |= (ocode << bit_offset) & 0xff; 254 output_byte(f, state->bit_buf); 255 256 bits = state->code_len - (8 - bit_offset); 257 ocode >>= 8 - bit_offset; 258 /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */ 259 if (bits >= 8) { 260 output_byte(f, ocode & 0xff); 261 ocode >>= 8; 262 bits -= 8; 263 } 264 /* Last bits. */ 265 state->bit_offset += state->code_len; 266 state->bit_buf = ocode & rmask[bits]; 267 if (state->bit_offset == state->code_len * 8) 268 state->bit_offset = 0; 269 270 /* 271 * If the next entry is going to be too big for the ocode size, 272 * then increase it, if possible. 273 */ 274 if (clear_flg || state->first_free > state->cur_maxcode) { 275 /* 276 * Write the whole buffer, because the input side won't 277 * discover the size increase until after it has read it. 278 */ 279 if (state->bit_offset > 0) { 280 while (state->bit_offset < state->code_len * 8) { 281 ret = output_byte(f, state->bit_buf); 282 if (ret != ARCHIVE_OK) 283 return ret; 284 state->bit_offset += 8; 285 state->bit_buf = 0; 286 } 287 } 288 state->bit_buf = 0; 289 state->bit_offset = 0; 290 291 if (clear_flg) { 292 state->code_len = 9; 293 state->cur_maxcode = MAXCODE(state->code_len); 294 } else { 295 state->code_len++; 296 if (state->code_len == 16) 297 state->cur_maxcode = state->max_maxcode; 298 else 299 state->cur_maxcode = MAXCODE(state->code_len); 300 } 301 } 302 303 return (ARCHIVE_OK); 304 } 305 306 static int 307 output_flush(struct archive_write_filter *f) 308 { 309 struct private_data *state = f->data; 310 int ret; 311 312 /* At EOF, write the rest of the buffer. */ 313 if (state->bit_offset % 8) { 314 state->code_len = (state->bit_offset % 8 + 7) / 8; 315 ret = output_byte(f, state->bit_buf); 316 if (ret != ARCHIVE_OK) 317 return ret; 318 } 319 320 return (ARCHIVE_OK); 321 } 322 323 /* 324 * Write data to the compressed stream. 325 */ 326 static int 327 archive_compressor_compress_write(struct archive_write_filter *f, 328 const void *buff, size_t length) 329 { 330 struct private_data *state = (struct private_data *)f->data; 331 int i; 332 int ratio; 333 int c, disp, ret; 334 const unsigned char *bp; 335 336 if (length == 0) 337 return ARCHIVE_OK; 338 339 bp = buff; 340 341 if (state->in_count == 0) { 342 state->cur_code = *bp++; 343 ++state->in_count; 344 --length; 345 } 346 347 while (length--) { 348 c = *bp++; 349 state->in_count++; 350 state->cur_fcode = (c << 16) + state->cur_code; 351 i = ((c << HSHIFT) ^ state->cur_code); /* Xor hashing. */ 352 353 if (state->hashtab[i] == state->cur_fcode) { 354 state->cur_code = state->codetab[i]; 355 continue; 356 } 357 if (state->hashtab[i] < 0) /* Empty slot. */ 358 goto nomatch; 359 /* Secondary hash (after G. Knott). */ 360 if (i == 0) 361 disp = 1; 362 else 363 disp = HSIZE - i; 364 probe: 365 if ((i -= disp) < 0) 366 i += HSIZE; 367 368 if (state->hashtab[i] == state->cur_fcode) { 369 state->cur_code = state->codetab[i]; 370 continue; 371 } 372 if (state->hashtab[i] >= 0) 373 goto probe; 374 nomatch: 375 ret = output_code(f, state->cur_code); 376 if (ret != ARCHIVE_OK) 377 return ret; 378 state->cur_code = c; 379 if (state->first_free < state->max_maxcode) { 380 state->codetab[i] = state->first_free++; /* code -> hashtable */ 381 state->hashtab[i] = state->cur_fcode; 382 continue; 383 } 384 if (state->in_count < state->checkpoint) 385 continue; 386 387 state->checkpoint = state->in_count + CHECK_GAP; 388 389 if (state->in_count <= 0x007fffff) 390 ratio = state->in_count * 256 / state->out_count; 391 else if ((ratio = state->out_count / 256) == 0) 392 ratio = 0x7fffffff; 393 else 394 ratio = state->in_count / ratio; 395 396 if (ratio > state->compress_ratio) 397 state->compress_ratio = ratio; 398 else { 399 state->compress_ratio = 0; 400 memset(state->hashtab, 0xff, sizeof(state->hashtab)); 401 state->first_free = FIRST; 402 ret = output_code(f, CLEAR); 403 if (ret != ARCHIVE_OK) 404 return ret; 405 } 406 } 407 408 return (ARCHIVE_OK); 409 } 410 411 412 /* 413 * Finish the compression... 414 */ 415 static int 416 archive_compressor_compress_close(struct archive_write_filter *f) 417 { 418 struct private_data *state = (struct private_data *)f->data; 419 int ret, ret2; 420 421 ret = output_code(f, state->cur_code); 422 if (ret != ARCHIVE_OK) 423 goto cleanup; 424 ret = output_flush(f); 425 if (ret != ARCHIVE_OK) 426 goto cleanup; 427 428 /* Write the last block */ 429 ret = __archive_write_filter(f->next_filter, 430 state->compressed, state->compressed_offset); 431 cleanup: 432 ret2 = __archive_write_close_filter(f->next_filter); 433 if (ret > ret2) 434 ret = ret2; 435 free(state->compressed); 436 free(state); 437 return (ret); 438 } 439 440 static int 441 archive_compressor_compress_free(struct archive_write_filter *f) 442 { 443 (void)f; /* UNUSED */ 444 return (ARCHIVE_OK); 445 } 446