diff options
Diffstat (limited to 'contrib/xz/src/liblzma/api/lzma/index_hash.h')
-rw-r--r-- | contrib/xz/src/liblzma/api/lzma/index_hash.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/contrib/xz/src/liblzma/api/lzma/index_hash.h b/contrib/xz/src/liblzma/api/lzma/index_hash.h new file mode 100644 index 0000000..94726e7 --- /dev/null +++ b/contrib/xz/src/liblzma/api/lzma/index_hash.h @@ -0,0 +1,107 @@ +/** + * \file lzma/index_hash.h + * \brief Validates Index by using a hash function + * + * Hashing makes it possible to use constant amount of memory to validate + * Index of arbitrary size. + */ + +/* + * Author: Lasse Collin + * + * This file has been put into the public domain. + * You can do whatever you want with this file. + * + * See ../lzma.h for information about liblzma as a whole. + */ + +#ifndef LZMA_H_INTERNAL +# error Never include this file directly. Use <lzma.h> instead. +#endif + +/** + * \brief Opaque data type to hold the Index hash + */ +typedef struct lzma_index_hash_s lzma_index_hash; + + +/** + * \brief Allocate and initialize a new lzma_index_hash structure + * + * If index_hash is NULL, a new lzma_index_hash structure is allocated, + * initialized, and a pointer to it returned. If allocation fails, NULL + * is returned. + * + * If index_hash 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 index_hash that was given as an argument. + */ +extern LZMA_API(lzma_index_hash *) lzma_index_hash_init( + lzma_index_hash *index_hash, lzma_allocator *allocator) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Deallocate lzma_index_hash structure + */ +extern LZMA_API(void) lzma_index_hash_end( + lzma_index_hash *index_hash, lzma_allocator *allocator) + lzma_nothrow; + + +/** + * \brief Add a new Record to an Index hash + * + * \param index Pointer to a lzma_index_hash structure + * \param unpadded_size Unpadded Size of a Block + * \param uncompressed_size Uncompressed Size of a Block + * + * \return - LZMA_OK + * - LZMA_DATA_ERROR: Compressed or uncompressed size of the + * Stream or size of the Index field would grow too big. + * - LZMA_PROG_ERROR: Invalid arguments or this function is being + * used when lzma_index_hash_decode() has already been used. + */ +extern LZMA_API(lzma_ret) lzma_index_hash_append(lzma_index_hash *index_hash, + lzma_vli unpadded_size, lzma_vli uncompressed_size) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Decode and validate the Index field + * + * After telling the sizes of all Blocks with lzma_index_hash_append(), + * the actual Index field is decoded with this function. Specifically, + * once decoding of the Index field has been started, no more Records + * can be added using lzma_index_hash_append(). + * + * This function doesn't use lzma_stream structure to pass the input data. + * Instead, the input buffer is specified using three arguments. This is + * because it matches better the internal APIs of liblzma. + * + * \param index_hash Pointer to a lzma_index_hash structure + * \param in Pointer to the beginning of the input buffer + * \param in_pos in[*in_pos] is the next byte to process + * \param in_size in[in_size] is the first byte not to process + * + * \return - LZMA_OK: So far good, but more input is needed. + * - LZMA_STREAM_END: Index decoded successfully and it matches + * the Records given with lzma_index_hash_append(). + * - LZMA_DATA_ERROR: Index is corrupt or doesn't match the + * information given with lzma_index_hash_append(). + * - LZMA_BUF_ERROR: Cannot progress because *in_pos >= in_size. + * - LZMA_PROG_ERROR + */ +extern LZMA_API(lzma_ret) lzma_index_hash_decode(lzma_index_hash *index_hash, + const uint8_t *in, size_t *in_pos, size_t in_size) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Get the size of the Index field as bytes + * + * This is needed to verify the Backward Size field in the Stream Footer. + */ +extern LZMA_API(lzma_vli) lzma_index_hash_size( + const lzma_index_hash *index_hash) + lzma_nothrow lzma_attr_pure; |