/**
* \file lzma/block.h
* \brief .lzma Block handling
*
* \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 <lzma.h> instead.
#endif
/**
* \brief Options for the Block Header encoder and decoder
*
* Different things use different parts of this structure. Some read
* some members, other functions write, and some do both. Only the
* members listed for reading need to be initialized when the specified
* functions are called. The members marked for writing will be assigned
* new values at some point either by calling the given function or by
* later calls to lzma_code().
*/
typedef struct {
/**
* \brief Size of the Block Header
*
* Read by:
* - lzma_block_header_encode()
* - lzma_block_header_decode()
* - lzma_block_decoder()
*
* Written by:
* - lzma_block_header_size()
*/
uint32_t header_size;
# define LZMA_BLOCK_HEADER_SIZE_MIN 8
# define LZMA_BLOCK_HEADER_SIZE_MAX 1024
/**
* \brief Type of integrity Check
*
* The type of the integrity Check is not stored into the Block
* Header, thus its value must be provided also when decoding.
*
* Read by:
* - lzma_block_header_encode()
* - lzma_block_header_decode()
* - lzma_block_encoder()
* - lzma_block_decoder()
*/
lzma_check check;
/**
* \brief Size of the Compressed Data in bytes
*
* Usually you don't know this value when encoding in streamed mode.
* In non-streamed mode you can reserve space for this field when
* encoding the Block Header the first time, and then re-encode the
* Block Header and copy it over the original one after the encoding
* of the Block has been finished.
*
* Read by:
* - lzma_block_header_size()
* - lzma_block_header_encode()
* - lzma_block_decoder()
*
* Written by:
* - lzma_block_header_decode()
* - lzma_block_encoder()
* - lzma_block_decoder()
*/
lzma_vli compressed_size;
/**
* \brief Uncompressed Size in bytes
*
* Encoder: If this value is not LZMA_VLI_VALUE_UNKNOWN, it is stored
* to the Uncompressed Size field in the Block Header. The real
* uncompressed size of the data being compressed must match
* the Uncompressed Size or LZMA_HEADER_ERROR is returned.
*
* If Uncompressed Size is unknown, End of Payload Marker must
* be used. If uncompressed_size == LZMA_VLI_VALUE_UNKNOWN and
* has_eopm == 0, LZMA_HEADER_ERROR will be returned.
*
* Decoder: If this value is not LZMA_VLI_VALUE_UNKNOWN, it is
* compared to the real Uncompressed Size. If they do not match,
* LZMA_HEADER_ERROR is returned.
*
* Read by:
* - lzma_block_header_size()
* - lzma_block_header_encode()
* - lzma_block_decoder()
*
* Written by:
* - lzma_block_header_decode()
* - lzma_block_encoder()
* - lzma_block_decoder()
*/
lzma_vli uncompressed_size;
/**
* \brief Array of filters
*
* There can be 1-4 filters. The end of the array is marked with
* .id = LZMA_VLI_VALUE_UNKNOWN.
*
* Read by:
* - lzma_block_header_size()
* - lzma_block_header_encode()
* - lzma_block_encoder()
* - lzma_block_decoder()
*
* Written by:
* - lzma_block_header_decode(): Note that this does NOT free()
* the old filter options structures. All unused filters[] will
* have .id == LZMA_VLI_VALUE_UNKNOWN and .options == NULL. If
* decoding fails, all filters[] are guaranteed to be
* LZMA_VLI_VALUE_UNKNOWN and NULL.
*
* \note Because of the array is terminated with
* .id = LZMA_VLI_VALUE_UNKNOWN, the actual array must
* have LZMA_BLOCK_FILTERS_MAX + 1 members or the Block
* Header decoder will overflow the buffer.
*/
lzma_filter *filters;
# define LZMA_BLOCK_FILTERS_MAX 4
} lzma_block;
/**
* \brief Decodes the Block Header Size field
*
* To decode Block Header using lzma_block_header_decode(), the size of the
* Block Header has to be known and stored into lzma_block.header_size.
* The size can be calculated from the first byte of a Block using this macro.
* Note that if the first byte is 0x00, it indicates beginning of Index; use
* this macro only when the byte is not 0x00.
*/
#define lzma_block_header_size_decode(b) (((uint32_t)(b) + 1) * 4)
/**
* \brief Calculates the size of Block Header
*
* \return - LZMA_OK: Size calculated successfully and stored to
* options->header_size.
* - LZMA_HEADER_ERROR: Unsupported filters or filter options.
* - LZMA_PROG_ERROR: Invalid options
*
* \note This doesn't check that all the options are valid i.e. this
* may return LZMA_OK even if lzma_block_header_encode() or
* lzma_block_encoder() would fail.
*/
extern lzma_ret lzma_block_header_size(lzma_block *options)
lzma_attr_warn_unused_result;
/**
* \brief Encodes Block Header
*
* Encoding of the Block options is done with a single call instead of
* first initializing and then doing the actual work with lzma_code().
*
* \param out Beginning of the output buffer. This must be
* at least options->header_size bytes.
* \param options Block options to be encoded.
*
* \return - LZMA_OK: Encoding was successful. options->header_size
* bytes were written to output buffer.
* - LZMA_HEADER_ERROR: Invalid or unsupported options.
* - LZMA_PROG_ERROR
*/
extern lzma_ret lzma_block_header_encode(
const lzma_block *options, uint8_t *out)
lzma_attr_warn_unused_result;
/**
* \brief Decodes Block Header
*
* Decoding of the Block options is done with a single call instead of
* first initializing and then doing the actual work with lzma_code().
*
* \param options Destination for block options
* \param allocator lzma_allocator for custom allocator functions.
* Set to NULL to use malloc().
* \param in Beginning of the input buffer. This must be
* at least options->header_size bytes.
*
* \return - LZMA_OK: Decoding was successful. options->header_size
* bytes were written to output buffer.
* - LZMA_HEADER_ERROR: Invalid or unsupported options.
* - LZMA_PROG_ERROR
*/
extern lzma_ret lzma_block_header_decode(lzma_block *options,
lzma_allocator *allocator, const uint8_t *in)
lzma_attr_warn_unused_result;
/**
* \brief Sets Compressed Size according to Total Size
*
* Block Header stores Compressed Size, but Index has Total Size. If the
* application has already parsed the Index and is now decoding Blocks,
* it can calculate Compressed Size from Total Size. This function does
* exactly that with error checking, so application doesn't need to check,
* for example, if the value in Index is too small to contain even the
* Block Header. Note that you need to call this function after decoding
* the Block Header field.
*
* \return - LZMA_OK: options->compressed_size was set successfully.
* - LZMA_DATA_ERROR: total_size is too small compared to
* options->header_size and lzma_check_sizes[options->check].
* - LZMA_PROG_ERROR: Some values are invalid. For example,
* total_size and options->header_size must be multiples
* of four, total_size must be at least 12, and
* options->header_size between 8 and 1024 inclusive.
*/
extern lzma_ret lzma_block_total_size_set(
lzma_block *options, lzma_vli total_size)
lzma_attr_warn_unused_result;
/**
* \brief Calculates Total Size
*
* This function can be useful after decoding a Block to get Total Size
* that is stored in Index.
*
* \return Total Size on success, or zero on error.
*/
extern lzma_vli lzma_block_total_size_get(const lzma_block *options)
lzma_attr_pure;
/**
* \brief Initializes .lzma Block encoder
*
* This function is required for multi-thread encoding. It may also be
* useful when implementing custom file formats.
*
* \return - LZMA_OK: All good, continue with lzma_code().
* - LZMA_MEM_ERROR
* - LZMA_HEADER_ERROR
* - LZMA_DATA_ERROR: Limits (total_limit and uncompressed_limit)
* have been reached already.
* - LZMA_UNSUPPORTED_CHECK: options->check specfies a Check
* that is not supported by this buid of liblzma. Initializing
* the encoder failed.
* - LZMA_PROG_ERROR
*
* lzma_code() can return FIXME
*/
extern lzma_ret lzma_block_encoder(lzma_stream *strm, lzma_block *options)
lzma_attr_warn_unused_result;
/**
* \brief Initializes decoder for .lzma Block
*
* \return - LZMA_OK: All good, continue with lzma_code().
* - LZMA_UNSUPPORTED_CHECK: Initialization was successful, but
* the given Check type is not supported, thus Check will be
* ignored.
* - LZMA_PROG_ERROR
* - LZMA_MEM_ERROR
*/
extern lzma_ret lzma_block_decoder(lzma_stream *strm, lzma_block *options)
lzma_attr_warn_unused_result;
