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| -rw-r--r-- | src/liblzma/api/lzma/info.h | 315 |
1 files changed, 315 insertions, 0 deletions
diff --git a/src/liblzma/api/lzma/info.h b/src/liblzma/api/lzma/info.h new file mode 100644 index 00000000..3a91850f --- /dev/null +++ b/src/liblzma/api/lzma/info.h @@ -0,0 +1,315 @@ +/** + * \file lzma/info.h + * \brief Handling of Stream size information + * + * \author Copyright (C) 1999-2006 Igor Pavlov + * \author Copyright (C) 2007 Lasse Collin + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + */ + +#ifndef LZMA_H_INTERNAL +# error Never include this file directly. Use <lzma.h> instead. +#endif + + +/********** + * Basics * + **********/ + +/** + * \brief Opaque data type to hold the size information + */ +typedef struct lzma_info_s lzma_info; + + +typedef struct { + /** + * \brief Total Size of this Block + * + * This can be LZMA_VLI_VALUE_UNKNOWN. + */ + lzma_vli total_size; + + /** + * \brief Uncompressed Size of this Block + * + * This can be LZMA_VLI_VALUE_UNKNOWN. + */ + lzma_vli uncompressed_size; + + /** + * \brief Offset of the first byte of the Block + * + * In encoder, this is useful to find out the alignment of the Block. + * + * In decoder, this is useful when doing random-access reading + * with help from lzma_info_data_locate(). + */ + lzma_vli stream_offset; + + /** + * \brief Uncompressed offset of the Block + * + * Offset of the first uncompressed byte of the Block relative to + * all uncompressed data in the Block. + * FIXME desc + */ + lzma_vli uncompressed_offset; + + /** + * \brief Pointers to internal data structures + * + * Applications must not touch these. + */ + void *internal[4]; + +} lzma_info_iter; + + +typedef enum { + LZMA_INFO_STREAM_START, + LZMA_INFO_HEADER_METADATA, + LZMA_INFO_TOTAL, + LZMA_INFO_UNCOMPRESSED, + LZMA_INFO_FOOTER_METADATA +} lzma_info_size; + + +/** + * \brief Allocates and initializes a new lzma_info structure + * + * If info is NULL, a new lzma_info structure is allocated, initialized, and + * a pointer to it returned. If allocation fails, NULL is returned. + * + * If info is non-NULL, it is reinitialized and the same pointer returned. + * (In this case, return value cannot be NULL or a different pointer than + * the info given as argument.) + */ +extern lzma_info *lzma_info_init(lzma_info *info, lzma_allocator *allocator); + + +/** + * \brief Resets lzma_info + * + * This is like calling lzma_info_end() and lzma_info_create(), but + * re-uses the existing base structure. + */ +extern void lzma_info_reset( + lzma_info *info, lzma_allocator *allocator); + + +/** + * \brief Frees memory allocated for a lzma_info structure + */ +extern void lzma_info_free(lzma_info *info, lzma_allocator *allocator); + + +/************************ + * Setting known values * + ************************/ + +/** + * \brief Set a known size value + * + * \param info Pointer returned by lzma_info_create() + * \param type Any value from lzma_info_size + * \param size Value to set or verify + * + * \return LZMA_OK on success, LZMA_DATA_ERROR if the size doesn't + * match the existing information, or LZMA_PROG_ERROR + * if type is invalid or size is not a valid VLI. + */ +extern lzma_ret lzma_info_size_set( + lzma_info *info, lzma_info_size type, lzma_vli size); + + +/** + * \brief Sets the Index + * + * The given lzma_index list is "absorbed" by this function. The application + * must not access it after this function call, even if this function returns + * an error. + * + * \note The given lzma_index will at some point get freed by the + * lzma_info_* functions. If you use a custom lzma_allocator, + * make sure that it can free the lzma_index. + */ +extern lzma_ret lzma_info_index_set( + lzma_info *info, lzma_allocator *allocator, + lzma_index *index, lzma_bool eat_index); + + +/** + * \brief Sets information from a known Metadata Block + * + * This is a shortcut for calling lzma_info_size_set() with different type + * arguments, lzma_info_index_set() with metadata->index. + */ +extern lzma_ret lzma_info_metadata_set(lzma_info *info, + lzma_allocator *allocator, lzma_metadata *metadata, + lzma_bool is_header_metadata, lzma_bool eat_index); + + +/*************** + * Incremental * + ***************/ + +/** + * \brief Prepares an iterator to be used with given lzma_info structure + * + * + */ +extern void lzma_info_iter_begin(lzma_info *info, lzma_info_iter *iter); + + +/** + * \brief Moves to the next Index Record + * + * + */ +extern lzma_ret lzma_info_iter_next( + lzma_info_iter *iter, lzma_allocator *allocator); + + +/** + * \brief Sets or verifies the sizes in the Index Record + * + * \param iter Pointer to iterator to be set or verified + * \param total_size + * Total Size in bytes or LZMA_VLI_VALUE_UNKNOWN + * \param uncompressed_size + * Uncompressed Size or LZMA_VLI_VALUE_UNKNOWN + * + * \return - LZMA_OK: All OK. + * - LZMA_DATA_ERROR: Given sizes don't match with the already + * known sizes. + * - LZMA_PROG_ERROR: Internal error, possibly integer + * overflow (e.g. the sum of all the known sizes is too big) + */ +extern lzma_ret lzma_info_iter_set(lzma_info_iter *iter, + lzma_vli total_size, lzma_vli uncompressed_size); + + +/** + * \brief Locates a Data Block + * + * \param iter Properly initialized iterator + * \param allocator Pointer to lzma_allocator or NULL + * \param uncompressed_offset + * Target offset to locate. The final offset + * will be equal or smaller than this. + * \param allow_alloc True if this function is allowed to call + * lzma_info_iter_next() to allocate a new Record + * if the requested offset reached end of Index + * Record list. Note that if Index has been marked + * final, lzma_info_iter_next() is never called. + * + * \return - LZMA_OK: All OK, *iter updated accordingly. + * - LZMA_DATA_ERROR: Trying to search past the end of the Index + * Record list, and allocating a new Record was not allowed + * either because allow_alloc was false or Index was final. + * - LZMA_PROG_ERROR: Internal error (probably integer + * overflow causing some lzma_vli getting too big). + */ +extern lzma_ret lzma_info_iter_locate(lzma_info_iter *iter, + lzma_allocator *allocator, lzma_vli uncompressed_offset, + lzma_bool allow_alloc); + + +/** + * \brief Finishes incrementally constructed Index + * + * This sets the known Total Size and Uncompressed of the Data Blocks + * based on the information collected from the Index Records, and marks + * the Index as final. + */ +extern lzma_ret lzma_info_index_finish(lzma_info *info); + + +/*************************** + * Reading the information * + ***************************/ + +/** + * \brief Gets a known size + * + * + */ +extern lzma_vli lzma_info_size_get( + const lzma_info *info, lzma_info_size type); + +extern lzma_vli lzma_info_metadata_locate( + const lzma_info *info, lzma_bool is_header_metadata); + +/** + * \brief Gets a pointer to the beginning of the Index list + * + * If detach is true, the Index will be detached from the lzma_info + * structure, and thus not be modified or freed by lzma_info_end(). + * + * If detach is false, the application must not modify the Index in any way. + * Also, the Index list is guaranteed to be valid only till the next call + * to any lzma_info_* function. + */ +extern lzma_index *lzma_info_index_get(lzma_info *info, lzma_bool detach); + + +extern size_t lzma_info_index_count_get(const lzma_info *info); + + +extern uint32_t lzma_info_metadata_alignment_get( + const lzma_info *info, lzma_bool is_header_metadata); + + + +/** + * \brief Locate a Block containing the given uncompressed offset + * + * This function is useful when you need to do random-access reading in + * a Multi-Block Stream. + * + * \param info Pointer to lzma_info that has at least one + * Index Record. The Index doesn't need to be finished. + * \param uncompressed_target + * Uncompressed target offset which the caller would + * like to locate from the Stream. + * \param stream_offset + * Starting offset (relative to the beginning the Stream) + * of the Block containing the requested location. + * \param uncompressed_offset + * The actual uncompressed offset of the beginning of + * the Block. uncompressed_offset <= uncompressed_target + * is always true; the application needs to uncompress + * uncompressed_target - uncompressed_offset bytes to + * reach the requested target offset. + * \param total_size + * Total Size of the Block. If the Index is incomplete, + * this may be LZMA_VLI_VALUE_UNKNOWN indicating unknown + * size. + * \param uncompressed_size + * Uncompressed Size of the Block. If the Index is + * incomplete, this may be LZMA_VLI_VALUE_UNKNOWN + * indicating unknown size. The application must pass + * this value to the Block decoder to verify FIXME + * + * \return + * + * \note This function is currently implemented as a linear search. + * If there are many Index Records, this can be really slow. + * This can be improved in newer liblzma versions if needed. + */ +extern lzma_bool lzma_info_data_locate(const lzma_info *info, + lzma_vli uncompressed_target, + lzma_vli *lzma_restrict stream_offset, + lzma_vli *lzma_restrict uncompressed_offset, + lzma_vli *lzma_restrict total_size, + lzma_vli *lzma_restrict uncompressed_size); |