/tmp/buildd/xz-utils-5.0.0/src/liblzma/common/block_header_encoder.c File Reference

Encodes Block Header for .xz files. More...

#include "common.h"
#include "check.h"

Functions
lzma_ret	lzma_block_header_size (lzma_block *block)
	Calculate Block Header Size.
lzma_ret	lzma_block_header_encode (const lzma_block *block, uint8_t *out)
	Encode Block Header.

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Detailed Description

Encodes Block Header for .xz files.

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Function Documentation

lzma_ret lzma_block_header_size

(

lzma_block *

block

)

Calculate Block Header Size.

Calculate the minimum size needed for the Block Header field using the settings specified in the lzma_block structure. Note that it is OK to increase the calculated header_size value as long as it is a multiple of four and doesn't exceed LZMA_BLOCK_HEADER_SIZE_MAX. Increasing header_size just means that lzma_block_header_encode() will add Header Padding.

Returns:

- LZMA_OK: Size calculated successfully and stored to block->header_size.

• LZMA_OPTIONS_ERROR: Unsupported version, filters or filter options.
• LZMA_PROG_ERROR: Invalid values like compressed_size == 0.

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. If you want to validate the filter chain, consider using lzma_memlimit_encoder() which as a side-effect validates the filter chain.

References lzma_filter_flags_size(), LZMA_FILTERS_MAX, lzma_vli_size(), LZMA_VLI_UNKNOWN, and return_if_error.

lzma_ret lzma_block_header_encode	(	const lzma_block *	block,
		uint8_t *	out
	)

Encode Block Header.

The caller must have calculated the size of the Block Header already with lzma_block_header_size(). If a value larger than the one calculated by lzma_block_header_size() is used, the Block Header will be padded to the specified size.

Parameters:

	out	Beginning of the output buffer. This must be at least block->header_size bytes.
	block	Block options to be encoded.

Returns:

- LZMA_OK: Encoding was successful. block->header_size bytes were written to output buffer.

• LZMA_OPTIONS_ERROR: Invalid or unsupported options.
• LZMA_PROG_ERROR: Invalid arguments, for example block->header_size is invalid or block->filters is NULL.

References lzma_block_unpadded_size(), lzma_crc32(), lzma_filter_flags_encode(), LZMA_FILTERS_MAX, lzma_vli_encode(), lzma_vli_is_valid, LZMA_VLI_UNKNOWN, and return_if_error.