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///////////////////////////////////////////////////////////////////////////////
//
/// \file block_header.c
/// \brief Utility functions to handle lzma_block
//
// Author: Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#include "common.h"
#include "index.h"
extern LZMA_API(lzma_ret)
lzma_block_compressed_size(lzma_block *block, lzma_vli unpadded_size)
{
// Validate everything but Uncompressed Size and filters.
if (lzma_block_unpadded_size(block) == 0)
return LZMA_PROG_ERROR;
const uint32_t container_size = block->header_size
+ lzma_check_size(block->check);
// Validate that Compressed Size will be greater than zero.
if (unpadded_size <= container_size)
return LZMA_DATA_ERROR;
// Calculate what Compressed Size is supposed to be.
// If Compressed Size was present in Block Header,
// compare that the new value matches it.
const lzma_vli compressed_size = unpadded_size - container_size;
if (block->compressed_size != LZMA_VLI_UNKNOWN
&& block->compressed_size != compressed_size)
return LZMA_DATA_ERROR;
block->compressed_size = compressed_size;
return LZMA_OK;
}
extern LZMA_API(lzma_vli)
lzma_block_unpadded_size(const lzma_block *block)
{
// Validate the values that we are interested in i.e. all but
// Uncompressed Size and the filters.
//
// NOTE: This function is used for validation too, so it is
// essential that these checks are always done even if
// Compressed Size is unknown.
if (block == NULL || block->version > 1
|| block->header_size < LZMA_BLOCK_HEADER_SIZE_MIN
|| block->header_size > LZMA_BLOCK_HEADER_SIZE_MAX
|| (block->header_size & 3)
|| !lzma_vli_is_valid(block->compressed_size)
|| block->compressed_size == 0
|| (unsigned int)(block->check) > LZMA_CHECK_ID_MAX)
return 0;
// If Compressed Size is unknown, return that we cannot know
// size of the Block either.
if (block->compressed_size == LZMA_VLI_UNKNOWN)
return LZMA_VLI_UNKNOWN;
// Calculate Unpadded Size and validate it.
const lzma_vli unpadded_size = block->compressed_size
+ block->header_size
+ lzma_check_size(block->check);
assert(unpadded_size >= UNPADDED_SIZE_MIN);
if (unpadded_size > UNPADDED_SIZE_MAX)
return 0;
return unpadded_size;
}
extern LZMA_API(lzma_vli)
lzma_block_total_size(const lzma_block *block)
{
lzma_vli unpadded_size = lzma_block_unpadded_size(block);
if (unpadded_size != LZMA_VLI_UNKNOWN)
unpadded_size = vli_ceil4(unpadded_size);
return unpadded_size;
}
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