78 lines
2.6 KiB
C
78 lines
2.6 KiB
C
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/*
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* nghttp2 - HTTP/2 C Library
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*
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* Copyright (c) 2013 Tatsuhiro Tsujikawa
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#ifndef NGHTTP2_HD_HUFFMAN_H
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#define NGHTTP2_HD_HUFFMAN_H
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif /* HAVE_CONFIG_H */
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#include <nghttp2/nghttp2.h>
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typedef enum {
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/* FSA accepts this state as the end of huffman encoding
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sequence. */
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NGHTTP2_HUFF_ACCEPTED = 1,
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/* This state emits symbol */
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NGHTTP2_HUFF_SYM = (1 << 1),
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/* If state machine reaches this state, decoding fails. */
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NGHTTP2_HUFF_FAIL = (1 << 2)
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} nghttp2_huff_decode_flag;
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typedef struct {
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/* huffman decoding state, which is actually the node ID of internal
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huffman tree. We have 257 leaf nodes, but they are identical to
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root node other than emitting a symbol, so we have 256 internal
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nodes [1..255], inclusive. */
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uint8_t state;
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/* bitwise OR of zero or more of the nghttp2_huff_decode_flag */
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uint8_t flags;
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/* symbol if NGHTTP2_HUFF_SYM flag set */
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uint8_t sym;
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} nghttp2_huff_decode;
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typedef nghttp2_huff_decode huff_decode_table_type[16];
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typedef struct {
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/* Current huffman decoding state. We stripped leaf nodes, so the
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value range is [0..255], inclusive. */
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uint8_t state;
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/* nonzero if we can say that the decoding process succeeds at this
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state */
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uint8_t accept;
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} nghttp2_hd_huff_decode_context;
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typedef struct {
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/* The number of bits in this code */
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uint32_t nbits;
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/* Huffman code aligned to LSB */
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uint32_t code;
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} nghttp2_huff_sym;
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extern const nghttp2_huff_sym huff_sym_table[];
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extern const nghttp2_huff_decode huff_decode_table[][16];
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#endif /* NGHTTP2_HD_HUFFMAN_H */
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