73 lines
2.5 KiB
C
73 lines
2.5 KiB
C
/*
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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 << 14,
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/* This state emits symbol */
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NGHTTP2_HUFF_SYM = 1 << 15,
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} nghttp2_huff_decode_flag;
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typedef struct {
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/* fstate is the current huffman decoding state, which is actually
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the node ID of internal huffman tree with
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nghttp2_huff_decode_flag OR-ed. We have 257 leaf nodes, but they
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are identical to root node other than emitting a symbol, so we
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have 256 internal nodes [1..255], inclusive. The node ID 256 is
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a special node and it is a terminal state that means decoding
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failed. */
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uint16_t fstate;
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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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/* fstate is the current huffman decoding state. */
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uint16_t fstate;
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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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