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https://github.com/cuberite/libdeflate.git
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f2c3a5b4e9
* Bring in common headers and program code from xpack project * Move program code to programs/ * Move library code to lib/ * GNU89 and MSVC2010 compatibility * Other changes
67 lines
2.2 KiB
C
67 lines
2.2 KiB
C
/*
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* deflate_constants.h - constants for the DEFLATE compression format
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*/
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#ifndef _LIB_DEFLATE_CONSTANTS_H
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#define _LIB_DEFLATE_CONSTANTS_H
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/* Valid block types */
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#define DEFLATE_BLOCKTYPE_UNCOMPRESSED 0
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#define DEFLATE_BLOCKTYPE_STATIC_HUFFMAN 1
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#define DEFLATE_BLOCKTYPE_DYNAMIC_HUFFMAN 2
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/* Minimum and maximum supported match lengths (in bytes) */
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#define DEFLATE_MIN_MATCH_LEN 3
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#define DEFLATE_MAX_MATCH_LEN 258
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/* Minimum and maximum supported match offsets (in bytes) */
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#define DEFLATE_MIN_MATCH_OFFSET 1
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#define DEFLATE_MAX_MATCH_OFFSET 32768
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#define DEFLATE_MAX_WINDOW_SIZE 32768
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/* Number of symbols in each Huffman code. Note: for the literal/length
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* and offset codes, these are actually the maximum values; a given block
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* might use fewer symbols. */
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#define DEFLATE_NUM_PRECODE_SYMS 19
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#define DEFLATE_NUM_LITLEN_SYMS 288
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#define DEFLATE_NUM_OFFSET_SYMS 32
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/* The maximum number of symbols across all codes */
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#define DEFLATE_MAX_NUM_SYMS 288
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/* Division of symbols in the literal/length code */
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#define DEFLATE_NUM_LITERALS 256
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#define DEFLATE_END_OF_BLOCK 256
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#define DEFLATE_NUM_LEN_SYMS 31
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/* Maximum codeword length, in bits, within each Huffman code */
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#define DEFLATE_MAX_PRE_CODEWORD_LEN 7
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#define DEFLATE_MAX_LITLEN_CODEWORD_LEN 15
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#define DEFLATE_MAX_OFFSET_CODEWORD_LEN 15
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/* The maximum codeword length across all codes */
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#define DEFLATE_MAX_CODEWORD_LEN 15
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/* Maximum possible overrun when decoding codeword lengths */
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#define DEFLATE_MAX_LENS_OVERRUN 137
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/*
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* Maximum number of extra bits that may be required to represent a match
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* length or offset.
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*
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* TODO: are we going to have full DEFLATE64 support? If so, up to 16
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* length bits must be supported.
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*/
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#define DEFLATE_MAX_EXTRA_LENGTH_BITS 5
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#define DEFLATE_MAX_EXTRA_OFFSET_BITS 14
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/* The maximum number of bits in which a match can be represented. This
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* is the absolute worst case, which assumes the longest possible Huffman
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* codewords and the maximum numbers of extra bits. */
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#define DEFLATE_MAX_MATCH_BITS \
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(DEFLATE_MAX_LITLEN_CODEWORD_LEN + DEFLATE_MAX_EXTRA_LENGTH_BITS + \
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DEFLATE_MAX_OFFSET_CODEWORD_LEN + DEFLATE_MAX_EXTRA_OFFSET_BITS)
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#endif /* _LIB_DEFLATE_CONSTANTS_H */
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