1 /** 2 * \file lzma/index_hash.h 3 * \brief Validate Index by using a hash function 4 * \note Never include this file directly. Use <lzma.h> instead. 5 * 6 * Hashing makes it possible to use constant amount of memory to validate 7 * Index of arbitrary size. 8 */ 9 10 /* 11 * Author: Lasse Collin 12 * 13 * This file has been put into the public domain. 14 * You can do whatever you want with this file. 15 */ 16 17 #ifndef LZMA_H_INTERNAL 18 # error Never include this file directly. Use <lzma.h> instead. 19 #endif 20 21 /** 22 * \brief Opaque data type to hold the Index hash 23 */ 24 typedef struct lzma_index_hash_s lzma_index_hash; 25 26 27 /** 28 * \brief Allocate and initialize a new lzma_index_hash structure 29 * 30 * If index_hash is NULL, this function allocates and initializes a new 31 * lzma_index_hash structure and returns a pointer to it. If allocation 32 * fails, NULL is returned. 33 * 34 * If index_hash is non-NULL, this function reinitializes the lzma_index_hash 35 * structure and returns the same pointer. In this case, return value cannot 36 * be NULL or a different pointer than the index_hash that was given as 37 * an argument. 38 * 39 * \param index_hash Pointer to a lzma_index_hash structure or NULL. 40 * \param allocator lzma_allocator for custom allocator functions. 41 * Set to NULL to use malloc() and free(). 42 * 43 * \return Initialized lzma_index_hash structure on success or 44 * NULL on failure. 45 */ 46 extern LZMA_API(lzma_index_hash *) lzma_index_hash_init( 47 lzma_index_hash *index_hash, const lzma_allocator *allocator) 48 lzma_nothrow lzma_attr_warn_unused_result; 49 50 51 /** 52 * \brief Deallocate lzma_index_hash structure 53 * 54 * \param index_hash Pointer to a lzma_index_hash structure to free. 55 * \param allocator lzma_allocator for custom allocator functions. 56 * Set to NULL to use malloc() and free(). 57 */ 58 extern LZMA_API(void) lzma_index_hash_end( 59 lzma_index_hash *index_hash, const lzma_allocator *allocator) 60 lzma_nothrow; 61 62 63 /** 64 * \brief Add a new Record to an Index hash 65 * 66 * \param index_hash Pointer to a lzma_index_hash structure 67 * \param unpadded_size Unpadded Size of a Block 68 * \param uncompressed_size Uncompressed Size of a Block 69 * 70 * \return Possible lzma_ret values: 71 * - LZMA_OK 72 * - LZMA_DATA_ERROR: Compressed or uncompressed size of the 73 * Stream or size of the Index field would grow too big. 74 * - LZMA_PROG_ERROR: Invalid arguments or this function is being 75 * used when lzma_index_hash_decode() has already been used. 76 */ 77 extern LZMA_API(lzma_ret) lzma_index_hash_append(lzma_index_hash *index_hash, 78 lzma_vli unpadded_size, lzma_vli uncompressed_size) 79 lzma_nothrow lzma_attr_warn_unused_result; 80 81 82 /** 83 * \brief Decode and validate the Index field 84 * 85 * After telling the sizes of all Blocks with lzma_index_hash_append(), 86 * the actual Index field is decoded with this function. Specifically, 87 * once decoding of the Index field has been started, no more Records 88 * can be added using lzma_index_hash_append(). 89 * 90 * This function doesn't use lzma_stream structure to pass the input data. 91 * Instead, the input buffer is specified using three arguments. This is 92 * because it matches better the internal APIs of liblzma. 93 * 94 * \param index_hash Pointer to a lzma_index_hash structure 95 * \param in Pointer to the beginning of the input buffer 96 * \param[out] in_pos in[*in_pos] is the next byte to process 97 * \param in_size in[in_size] is the first byte not to process 98 * 99 * \return Possible lzma_ret values: 100 * - LZMA_OK: So far good, but more input is needed. 101 * - LZMA_STREAM_END: Index decoded successfully and it matches 102 * the Records given with lzma_index_hash_append(). 103 * - LZMA_DATA_ERROR: Index is corrupt or doesn't match the 104 * information given with lzma_index_hash_append(). 105 * - LZMA_BUF_ERROR: Cannot progress because *in_pos >= in_size. 106 * - LZMA_PROG_ERROR 107 */ 108 extern LZMA_API(lzma_ret) lzma_index_hash_decode(lzma_index_hash *index_hash, 109 const uint8_t *in, size_t *in_pos, size_t in_size) 110 lzma_nothrow lzma_attr_warn_unused_result; 111 112 113 /** 114 * \brief Get the size of the Index field as bytes 115 * 116 * This is needed to verify the Backward Size field in the Stream Footer. 117 * 118 * \param index_hash Pointer to a lzma_index_hash structure 119 * 120 * \return Size of the Index field in bytes. 121 */ 122 extern LZMA_API(lzma_vli) lzma_index_hash_size( 123 const lzma_index_hash *index_hash) 124 lzma_nothrow lzma_attr_pure; 125