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      1 /* SPDX-License-Identifier: 0BSD */
      2 
      3 /**
      4  * \file        lzma/index_hash.h
      5  * \brief       Validate Index by using a hash function
      6  * \note        Never include this file directly. Use <lzma.h> instead.
      7  *
      8  * Hashing makes it possible to use constant amount of memory to validate
      9  * Index of arbitrary size.
     10  */
     11 
     12 /*
     13  * Author: Lasse Collin
     14  */
     15 
     16 #ifndef LZMA_H_INTERNAL
     17 #	error Never include this file directly. Use <lzma.h> instead.
     18 #endif
     19 
     20 /**
     21  * \brief       Opaque data type to hold the Index hash
     22  */
     23 typedef struct lzma_index_hash_s lzma_index_hash;
     24 
     25 
     26 /**
     27  * \brief       Allocate and initialize a new lzma_index_hash structure
     28  *
     29  * If index_hash is NULL, this function allocates and initializes a new
     30  * lzma_index_hash structure and returns a pointer to it. If allocation
     31  * fails, NULL is returned.
     32  *
     33  * If index_hash is non-NULL, this function reinitializes the lzma_index_hash
     34  * structure and returns the same pointer. In this case, return value cannot
     35  * be NULL or a different pointer than the index_hash that was given as
     36  * an argument.
     37  *
     38  * \param       index_hash  Pointer to a lzma_index_hash structure or NULL.
     39  * \param       allocator   lzma_allocator for custom allocator functions.
     40  *                          Set to NULL to use malloc() and free().
     41  *
     42  * \return      Initialized lzma_index_hash structure on success or
     43  *              NULL on failure.
     44  */
     45 extern LZMA_API(lzma_index_hash *) lzma_index_hash_init(
     46 		lzma_index_hash *index_hash, const lzma_allocator *allocator)
     47 		lzma_nothrow lzma_attr_warn_unused_result;
     48 
     49 
     50 /**
     51  * \brief       Deallocate lzma_index_hash structure
     52  *
     53  * \param       index_hash  Pointer to a lzma_index_hash structure to free.
     54  * \param       allocator   lzma_allocator for custom allocator functions.
     55  *                          Set to NULL to use malloc() and free().
     56  */
     57 extern LZMA_API(void) lzma_index_hash_end(
     58 		lzma_index_hash *index_hash, const lzma_allocator *allocator)
     59 		lzma_nothrow;
     60 
     61 
     62 /**
     63  * \brief       Add a new Record to an Index hash
     64  *
     65  * \param       index_hash        Pointer to a lzma_index_hash structure
     66  * \param       unpadded_size     Unpadded Size of a Block
     67  * \param       uncompressed_size Uncompressed Size of a Block
     68  *
     69  * \return      Possible lzma_ret values:
     70  *              - LZMA_OK
     71  *              - LZMA_DATA_ERROR: Compressed or uncompressed size of the
     72  *                Stream or size of the Index field would grow too big.
     73  *              - LZMA_PROG_ERROR: Invalid arguments or this function is being
     74  *                used when lzma_index_hash_decode() has already been used.
     75  */
     76 extern LZMA_API(lzma_ret) lzma_index_hash_append(lzma_index_hash *index_hash,
     77 		lzma_vli unpadded_size, lzma_vli uncompressed_size)
     78 		lzma_nothrow lzma_attr_warn_unused_result;
     79 
     80 
     81 /**
     82  * \brief       Decode and validate the Index field
     83  *
     84  * After telling the sizes of all Blocks with lzma_index_hash_append(),
     85  * the actual Index field is decoded with this function. Specifically,
     86  * once decoding of the Index field has been started, no more Records
     87  * can be added using lzma_index_hash_append().
     88  *
     89  * This function doesn't use lzma_stream structure to pass the input data.
     90  * Instead, the input buffer is specified using three arguments. This is
     91  * because it matches better the internal APIs of liblzma.
     92  *
     93  * \param       index_hash      Pointer to a lzma_index_hash structure
     94  * \param       in              Pointer to the beginning of the input buffer
     95  * \param[out]  in_pos          in[*in_pos] is the next byte to process
     96  * \param       in_size         in[in_size] is the first byte not to process
     97  *
     98  * \return      Possible lzma_ret values:
     99  *              - LZMA_OK: So far good, but more input is needed.
    100  *              - LZMA_STREAM_END: Index decoded successfully and it matches
    101  *                the Records given with lzma_index_hash_append().
    102  *              - LZMA_DATA_ERROR: Index is corrupt or doesn't match the
    103  *                information given with lzma_index_hash_append().
    104  *              - LZMA_BUF_ERROR: Cannot progress because *in_pos >= in_size.
    105  *              - LZMA_PROG_ERROR
    106  */
    107 extern LZMA_API(lzma_ret) lzma_index_hash_decode(lzma_index_hash *index_hash,
    108 		const uint8_t *in, size_t *in_pos, size_t in_size)
    109 		lzma_nothrow lzma_attr_warn_unused_result;
    110 
    111 
    112 /**
    113  * \brief       Get the size of the Index field as bytes
    114  *
    115  * This is needed to verify the Backward Size field in the Stream Footer.
    116  *
    117  * \param       index_hash      Pointer to a lzma_index_hash structure
    118  *
    119  * \return      Size of the Index field in bytes.
    120  */
    121 extern LZMA_API(lzma_vli) lzma_index_hash_size(
    122 		const lzma_index_hash *index_hash)
    123 		lzma_nothrow lzma_attr_pure;
    124