1 /** 2 * \file lzma/base.h 3 * \brief Data types and functions used in many places in liblzma API 4 */ 5 6 /* 7 * Author: Lasse Collin 8 * 9 * This file has been put into the public domain. 10 * You can do whatever you want with this file. 11 * 12 * See ../lzma.h for information about liblzma as a whole. 13 */ 14 15 #ifndef LZMA_H_INTERNAL 16 # error Never include this file directly. Use <lzma.h> instead. 17 #endif 18 19 20 /** 21 * \brief Boolean 22 * 23 * This is here because C89 doesn't have stdbool.h. To set a value for 24 * variables having type lzma_bool, you can use 25 * - C99's `true' and `false' from stdbool.h; 26 * - C++'s internal `true' and `false'; or 27 * - integers one (true) and zero (false). 28 */ 29 typedef unsigned char lzma_bool; 30 31 32 /** 33 * \brief Type of reserved enumeration variable in structures 34 * 35 * To avoid breaking library ABI when new features are added, several 36 * structures contain extra variables that may be used in future. Since 37 * sizeof(enum) can be different than sizeof(int), and sizeof(enum) may 38 * even vary depending on the range of enumeration constants, we specify 39 * a separate type to be used for reserved enumeration variables. All 40 * enumeration constants in liblzma API will be non-negative and less 41 * than 128, which should guarantee that the ABI won't break even when 42 * new constants are added to existing enumerations. 43 */ 44 typedef enum { 45 LZMA_RESERVED_ENUM = 0 46 } lzma_reserved_enum; 47 48 49 /** 50 * \brief Return values used by several functions in liblzma 51 * 52 * Check the descriptions of specific functions to find out which return 53 * values they can return. With some functions the return values may have 54 * more specific meanings than described here; those differences are 55 * described per-function basis. 56 */ 57 typedef enum { 58 LZMA_OK = 0, 59 /**< 60 * \brief Operation completed successfully 61 */ 62 63 LZMA_STREAM_END = 1, 64 /**< 65 * \brief End of stream was reached 66 * 67 * In encoder, LZMA_SYNC_FLUSH, LZMA_FULL_FLUSH, or 68 * LZMA_FINISH was finished. In decoder, this indicates 69 * that all the data was successfully decoded. 70 * 71 * In all cases, when LZMA_STREAM_END is returned, the last 72 * output bytes should be picked from strm->next_out. 73 */ 74 75 LZMA_NO_CHECK = 2, 76 /**< 77 * \brief Input stream has no integrity check 78 * 79 * This return value can be returned only if the 80 * LZMA_TELL_NO_CHECK flag was used when initializing 81 * the decoder. LZMA_NO_CHECK is just a warning, and 82 * the decoding can be continued normally. 83 * 84 * It is possible to call lzma_get_check() immediately after 85 * lzma_code has returned LZMA_NO_CHECK. The result will 86 * naturally be LZMA_CHECK_NONE, but the possibility to call 87 * lzma_get_check() may be convenient in some applications. 88 */ 89 90 LZMA_UNSUPPORTED_CHECK = 3, 91 /**< 92 * \brief Cannot calculate the integrity check 93 * 94 * The usage of this return value is different in encoders 95 * and decoders. 96 * 97 * Encoders can return this value only from the initialization 98 * function. If initialization fails with this value, the 99 * encoding cannot be done, because there's no way to produce 100 * output with the correct integrity check. 101 * 102 * Decoders can return this value only from lzma_code() and 103 * only if the LZMA_TELL_UNSUPPORTED_CHECK flag was used when 104 * initializing the decoder. The decoding can still be 105 * continued normally even if the check type is unsupported, 106 * but naturally the check will not be validated, and possible 107 * errors may go undetected. 108 * 109 * With decoder, it is possible to call lzma_get_check() 110 * immediately after lzma_code() has returned 111 * LZMA_UNSUPPORTED_CHECK. This way it is possible to find 112 * out what the unsupported Check ID was. 113 */ 114 115 LZMA_GET_CHECK = 4, 116 /**< 117 * \brief Integrity check type is now available 118 * 119 * This value can be returned only by the lzma_code() function 120 * and only if the decoder was initialized with the 121 * LZMA_TELL_ANY_CHECK flag. LZMA_GET_CHECK tells the 122 * application that it may now call lzma_get_check() to find 123 * out the Check ID. This can be used, for example, to 124 * implement a decoder that accepts only files that have 125 * strong enough integrity check. 126 */ 127 128 LZMA_MEM_ERROR = 5, 129 /**< 130 * \brief Cannot allocate memory 131 * 132 * Memory allocation failed, or the size of the allocation 133 * would be greater than SIZE_MAX. 134 * 135 * Due to internal implementation reasons, the coding cannot 136 * be continued even if more memory were made available after 137 * LZMA_MEM_ERROR. 138 */ 139 140 LZMA_MEMLIMIT_ERROR = 6, 141 /** 142 * \brief Memory usage limit was reached 143 * 144 * Decoder would need more memory than allowed by the 145 * specified memory usage limit. To continue decoding, 146 * the memory usage limit has to be increased with 147 * lzma_memlimit_set(). 148 */ 149 150 LZMA_FORMAT_ERROR = 7, 151 /**< 152 * \brief File format not recognized 153 * 154 * The decoder did not recognize the input as supported file 155 * format. This error can occur, for example, when trying to 156 * decode .lzma format file with lzma_stream_decoder, 157 * because lzma_stream_decoder accepts only the .xz format. 158 */ 159 160 LZMA_OPTIONS_ERROR = 8, 161 /**< 162 * \brief Invalid or unsupported options 163 * 164 * Invalid or unsupported options, for example 165 * - unsupported filter(s) or filter options; or 166 * - reserved bits set in headers (decoder only). 167 * 168 * Rebuilding liblzma with more features enabled, or 169 * upgrading to a newer version of liblzma may help. 170 */ 171 172 LZMA_DATA_ERROR = 9, 173 /**< 174 * \brief Data is corrupt 175 * 176 * The usage of this return value is different in encoders 177 * and decoders. In both encoder and decoder, the coding 178 * cannot continue after this error. 179 * 180 * Encoders return this if size limits of the target file 181 * format would be exceeded. These limits are huge, thus 182 * getting this error from an encoder is mostly theoretical. 183 * For example, the maximum compressed and uncompressed 184 * size of a .xz Stream is roughly 8 EiB (2^63 bytes). 185 * 186 * Decoders return this error if the input data is corrupt. 187 * This can mean, for example, invalid CRC32 in headers 188 * or invalid check of uncompressed data. 189 */ 190 191 LZMA_BUF_ERROR = 10, 192 /**< 193 * \brief No progress is possible 194 * 195 * This error code is returned when the coder cannot consume 196 * any new input and produce any new output. The most common 197 * reason for this error is that the input stream being 198 * decoded is truncated or corrupt. 199 * 200 * This error is not fatal. Coding can be continued normally 201 * by providing more input and/or more output space, if 202 * possible. 203 * 204 * Typically the first call to lzma_code() that can do no 205 * progress returns LZMA_OK instead of LZMA_BUF_ERROR. Only 206 * the second consecutive call doing no progress will return 207 * LZMA_BUF_ERROR. This is intentional. 208 * 209 * With zlib, Z_BUF_ERROR may be returned even if the 210 * application is doing nothing wrong, so apps will need 211 * to handle Z_BUF_ERROR specially. The above hack 212 * guarantees that liblzma never returns LZMA_BUF_ERROR 213 * to properly written applications unless the input file 214 * is truncated or corrupt. This should simplify the 215 * applications a little. 216 */ 217 218 LZMA_PROG_ERROR = 11, 219 /**< 220 * \brief Programming error 221 * 222 * This indicates that the arguments given to the function are 223 * invalid or the internal state of the decoder is corrupt. 224 * - Function arguments are invalid or the structures 225 * pointed by the argument pointers are invalid 226 * e.g. if strm->next_out has been set to NULL and 227 * strm->avail_out > 0 when calling lzma_code(). 228 * - lzma_* functions have been called in wrong order 229 * e.g. lzma_code() was called right after lzma_end(). 230 * - If errors occur randomly, the reason might be flaky 231 * hardware. 232 * 233 * If you think that your code is correct, this error code 234 * can be a sign of a bug in liblzma. See the documentation 235 * how to report bugs. 236 */ 237 } lzma_ret; 238 239 240 /** 241 * \brief The `action' argument for lzma_code() 242 * 243 * After the first use of LZMA_SYNC_FLUSH, LZMA_FULL_FLUSH, or LZMA_FINISH, 244 * the same `action' must is used until lzma_code() returns LZMA_STREAM_END. 245 * Also, the amount of input (that is, strm->avail_in) must not be modified 246 * by the application until lzma_code() returns LZMA_STREAM_END. Changing the 247 * `action' or modifying the amount of input will make lzma_code() return 248 * LZMA_PROG_ERROR. 249 */ 250 typedef enum { 251 LZMA_RUN = 0, 252 /**< 253 * \brief Continue coding 254 * 255 * Encoder: Encode as much input as possible. Some internal 256 * buffering will probably be done (depends on the filter 257 * chain in use), which causes latency: the input used won't 258 * usually be decodeable from the output of the same 259 * lzma_code() call. 260 * 261 * Decoder: Decode as much input as possible and produce as 262 * much output as possible. 263 */ 264 265 LZMA_SYNC_FLUSH = 1, 266 /**< 267 * \brief Make all the input available at output 268 * 269 * Normally the encoder introduces some latency. 270 * LZMA_SYNC_FLUSH forces all the buffered data to be 271 * available at output without resetting the internal 272 * state of the encoder. This way it is possible to use 273 * compressed stream for example for communication over 274 * network. 275 * 276 * Only some filters support LZMA_SYNC_FLUSH. Trying to use 277 * LZMA_SYNC_FLUSH with filters that don't support it will 278 * make lzma_code() return LZMA_OPTIONS_ERROR. For example, 279 * LZMA1 doesn't support LZMA_SYNC_FLUSH but LZMA2 does. 280 * 281 * Using LZMA_SYNC_FLUSH very often can dramatically reduce 282 * the compression ratio. With some filters (for example, 283 * LZMA2), fine-tuning the compression options may help 284 * mitigate this problem significantly. 285 * 286 * Decoders don't support LZMA_SYNC_FLUSH. 287 */ 288 289 LZMA_FULL_FLUSH = 2, 290 /**< 291 * \brief Make all the input available at output 292 * 293 * Finish encoding of the current Block. All the input 294 * data going to the current Block must have been given 295 * to the encoder (the last bytes can still be pending in 296 * next_in). Call lzma_code() with LZMA_FULL_FLUSH until 297 * it returns LZMA_STREAM_END. Then continue normally with 298 * LZMA_RUN or finish the Stream with LZMA_FINISH. 299 * 300 * This action is currently supported only by Stream encoder 301 * and easy encoder (which uses Stream encoder). If there is 302 * no unfinished Block, no empty Block is created. 303 */ 304 305 LZMA_FINISH = 3 306 /**< 307 * \brief Finish the coding operation 308 * 309 * Finishes the coding operation. All the input data must 310 * have been given to the encoder (the last bytes can still 311 * be pending in next_in). Call lzma_code() with LZMA_FINISH 312 * until it returns LZMA_STREAM_END. Once LZMA_FINISH has 313 * been used, the amount of input must no longer be changed 314 * by the application. 315 * 316 * When decoding, using LZMA_FINISH is optional unless the 317 * LZMA_CONCATENATED flag was used when the decoder was 318 * initialized. When LZMA_CONCATENATED was not used, the only 319 * effect of LZMA_FINISH is that the amount of input must not 320 * be changed just like in the encoder. 321 */ 322 } lzma_action; 323 324 325 /** 326 * \brief Custom functions for memory handling 327 * 328 * A pointer to lzma_allocator may be passed via lzma_stream structure 329 * to liblzma, and some advanced functions take a pointer to lzma_allocator 330 * as a separate function argument. The library will use the functions 331 * specified in lzma_allocator for memory handling instead of the default 332 * malloc() and free(). C++ users should note that the custom memory 333 * handling functions must not throw exceptions. 334 * 335 * liblzma doesn't make an internal copy of lzma_allocator. Thus, it is 336 * OK to change these function pointers in the middle of the coding 337 * process, but obviously it must be done carefully to make sure that the 338 * replacement `free' can deallocate memory allocated by the earlier 339 * `alloc' function(s). 340 */ 341 typedef struct { 342 /** 343 * \brief Pointer to a custom memory allocation function 344 * 345 * If you don't want a custom allocator, but still want 346 * custom free(), set this to NULL and liblzma will use 347 * the standard malloc(). 348 * 349 * \param opaque lzma_allocator.opaque (see below) 350 * \param nmemb Number of elements like in calloc(). liblzma 351 * will always set nmemb to 1, so it is safe to 352 * ignore nmemb in a custom allocator if you like. 353 * The nmemb argument exists only for 354 * compatibility with zlib and libbzip2. 355 * \param size Size of an element in bytes. 356 * liblzma never sets this to zero. 357 * 358 * \return Pointer to the beginning of a memory block of 359 * `size' bytes, or NULL if allocation fails 360 * for some reason. When allocation fails, functions 361 * of liblzma return LZMA_MEM_ERROR. 362 * 363 * The allocator should not waste time zeroing the allocated buffers. 364 * This is not only about speed, but also memory usage, since the 365 * operating system kernel doesn't necessarily allocate the requested 366 * memory in physical memory until it is actually used. With small 367 * input files, liblzma may actually need only a fraction of the 368 * memory that it requested for allocation. 369 * 370 * \note LZMA_MEM_ERROR is also used when the size of the 371 * allocation would be greater than SIZE_MAX. Thus, 372 * don't assume that the custom allocator must have 373 * returned NULL if some function from liblzma 374 * returns LZMA_MEM_ERROR. 375 */ 376 void *(LZMA_API_CALL *alloc)(void *opaque, size_t nmemb, size_t size); 377 378 /** 379 * \brief Pointer to a custom memory freeing function 380 * 381 * If you don't want a custom freeing function, but still 382 * want a custom allocator, set this to NULL and liblzma 383 * will use the standard free(). 384 * 385 * \param opaque lzma_allocator.opaque (see below) 386 * \param ptr Pointer returned by lzma_allocator.alloc(), 387 * or when it is set to NULL, a pointer returned 388 * by the standard malloc(). 389 */ 390 void (LZMA_API_CALL *free)(void *opaque, void *ptr); 391 392 /** 393 * \brief Pointer passed to .alloc() and .free() 394 * 395 * opaque is passed as the first argument to lzma_allocator.alloc() 396 * and lzma_allocator.free(). This intended to ease implementing 397 * custom memory allocation functions for use with liblzma. 398 * 399 * If you don't need this, you should set this to NULL. 400 */ 401 void *opaque; 402 403 } lzma_allocator; 404 405 406 /** 407 * \brief Internal data structure 408 * 409 * The contents of this structure is not visible outside the library. 410 */ 411 typedef struct lzma_internal_s lzma_internal; 412 413 414 /** 415 * \brief Passing data to and from liblzma 416 * 417 * The lzma_stream structure is used for 418 * - passing pointers to input and output buffers to liblzma; 419 * - defining custom memory hander functions; and 420 * - holding a pointer to coder-specific internal data structures. 421 * 422 * Typical usage: 423 * 424 * - After allocating lzma_stream (on stack or with malloc()), it must be 425 * initialized to LZMA_STREAM_INIT (see LZMA_STREAM_INIT for details). 426 * 427 * - Initialize a coder to the lzma_stream, for example by using 428 * lzma_easy_encoder() or lzma_auto_decoder(). Some notes: 429 * - In contrast to zlib, strm->next_in and strm->next_out are 430 * ignored by all initialization functions, thus it is safe 431 * to not initialize them yet. 432 * - The initialization functions always set strm->total_in and 433 * strm->total_out to zero. 434 * - If the initialization function fails, no memory is left allocated 435 * that would require freeing with lzma_end() even if some memory was 436 * associated with the lzma_stream structure when the initialization 437 * function was called. 438 * 439 * - Use lzma_code() to do the actual work. 440 * 441 * - Once the coding has been finished, the existing lzma_stream can be 442 * reused. It is OK to reuse lzma_stream with different initialization 443 * function without calling lzma_end() first. Old allocations are 444 * automatically freed. 445 * 446 * - Finally, use lzma_end() to free the allocated memory. lzma_end() never 447 * frees the lzma_stream structure itself. 448 * 449 * Application may modify the values of total_in and total_out as it wants. 450 * They are updated by liblzma to match the amount of data read and 451 * written, but aren't used for anything else. 452 */ 453 typedef struct { 454 const uint8_t *next_in; /**< Pointer to the next input byte. */ 455 size_t avail_in; /**< Number of available input bytes in next_in. */ 456 uint64_t total_in; /**< Total number of bytes read by liblzma. */ 457 458 uint8_t *next_out; /**< Pointer to the next output position. */ 459 size_t avail_out; /**< Amount of free space in next_out. */ 460 uint64_t total_out; /**< Total number of bytes written by liblzma. */ 461 462 /** 463 * \brief Custom memory allocation functions 464 * 465 * In most cases this is NULL which makes liblzma use 466 * the standard malloc() and free(). 467 */ 468 lzma_allocator *allocator; 469 470 /** Internal state is not visible to applications. */ 471 lzma_internal *internal; 472 473 /* 474 * Reserved space to allow possible future extensions without 475 * breaking the ABI. Excluding the initialization of this structure, 476 * you should not touch these, because the names of these variables 477 * may change. 478 */ 479 void *reserved_ptr1; 480 void *reserved_ptr2; 481 uint64_t reserved_int1; 482 uint64_t reserved_int2; 483 lzma_reserved_enum reserved_enum1; 484 lzma_reserved_enum reserved_enum2; 485 486 } lzma_stream; 487 488 489 /** 490 * \brief Initialization for lzma_stream 491 * 492 * When you declare an instance of lzma_stream, you can immediately 493 * initialize it so that initialization functions know that no memory 494 * has been allocated yet: 495 * 496 * lzma_stream strm = LZMA_STREAM_INIT; 497 * 498 * If you need to initialize a dynamically allocated lzma_stream, you can use 499 * memset(strm_pointer, 0, sizeof(lzma_stream)). Strictly speaking, this 500 * violates the C standard since NULL may have different internal 501 * representation than zero, but it should be portable enough in practice. 502 * Anyway, for maximum portability, you can use something like this: 503 * 504 * lzma_stream tmp = LZMA_STREAM_INIT; 505 * *strm = tmp; 506 */ 507 #define LZMA_STREAM_INIT \ 508 { NULL, 0, 0, NULL, 0, 0, NULL, NULL, \ 509 NULL, NULL, 0, 0, LZMA_RESERVED_ENUM, LZMA_RESERVED_ENUM } 510 511 512 /** 513 * \brief Encode or decode data 514 * 515 * Once the lzma_stream has been successfully initialized (e.g. with 516 * lzma_stream_encoder()), the actual encoding or decoding is done 517 * using this function. The application has to update strm->next_in, 518 * strm->avail_in, strm->next_out, and strm->avail_out to pass input 519 * to and get output from liblzma. 520 * 521 * See the description of the coder-specific initialization function to find 522 * out what `action' values are supported by the coder. 523 */ 524 extern LZMA_API(lzma_ret) lzma_code(lzma_stream *strm, lzma_action action) 525 lzma_nothrow lzma_attr_warn_unused_result; 526 527 528 /** 529 * \brief Free memory allocated for the coder data structures 530 * 531 * \param strm Pointer to lzma_stream that is at least initialized 532 * with LZMA_STREAM_INIT. 533 * 534 * After lzma_end(strm), strm->internal is guaranteed to be NULL. No other 535 * members of the lzma_stream structure are touched. 536 * 537 * \note zlib indicates an error if application end()s unfinished 538 * stream structure. liblzma doesn't do this, and assumes that 539 * application knows what it is doing. 540 */ 541 extern LZMA_API(void) lzma_end(lzma_stream *strm) lzma_nothrow; 542 543 544 /** 545 * \brief Get the memory usage of decoder filter chain 546 * 547 * This function is currently supported only when *strm has been initialized 548 * with a function that takes a memlimit argument. With other functions, you 549 * should use e.g. lzma_raw_encoder_memusage() or lzma_raw_decoder_memusage() 550 * to estimate the memory requirements. 551 * 552 * This function is useful e.g. after LZMA_MEMLIMIT_ERROR to find out how big 553 * the memory usage limit should have been to decode the input. Note that 554 * this may give misleading information if decoding .xz Streams that have 555 * multiple Blocks, because each Block can have different memory requirements. 556 * 557 * \return Rough estimate of how much memory is currently allocated 558 * for the filter decoders. If no filter chain is currently 559 * allocated, some non-zero value is still returned, which is 560 * less than or equal to what any filter chain would indicate 561 * as its memory requirement. 562 * 563 * If this function isn't supported by *strm or some other error 564 * occurs, zero is returned. 565 */ 566 extern LZMA_API(uint64_t) lzma_memusage(const lzma_stream *strm) 567 lzma_nothrow lzma_attr_pure; 568 569 570 /** 571 * \brief Get the current memory usage limit 572 * 573 * This function is supported only when *strm has been initialized with 574 * a function that takes a memlimit argument. 575 * 576 * \return On success, the current memory usage limit is returned 577 * (always non-zero). On error, zero is returned. 578 */ 579 extern LZMA_API(uint64_t) lzma_memlimit_get(const lzma_stream *strm) 580 lzma_nothrow lzma_attr_pure; 581 582 583 /** 584 * \brief Set the memory usage limit 585 * 586 * This function is supported only when *strm has been initialized with 587 * a function that takes a memlimit argument. 588 * 589 * \return - LZMA_OK: New memory usage limit successfully set. 590 * - LZMA_MEMLIMIT_ERROR: The new limit is too small. 591 * The limit was not changed. 592 * - LZMA_PROG_ERROR: Invalid arguments, e.g. *strm doesn't 593 * support memory usage limit or memlimit was zero. 594 */ 595 extern LZMA_API(lzma_ret) lzma_memlimit_set( 596 lzma_stream *strm, uint64_t memlimit) lzma_nothrow; 597