LCOM1920-T02G10

/**

 * \file        lzma/index_hash.h

 * \brief       Validate 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, const 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, const 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;