/** * \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 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);