452 lines
21 KiB
Python
Executable File
452 lines
21 KiB
Python
Executable File
#!/usr/bin/env python
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# -*- coding: utf-8 -*-
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# This script reads Huffman Code table [1] and generates symbol table
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# and decoding tables in C language. The resulting code is used in
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# lib/nghttp2_hd_huffman.h and lib/nghttp2_hd_huffman_data.c
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#
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# [1] http://http2.github.io/http2-spec/compression.html
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from __future__ import unicode_literals
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import re
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import sys
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import StringIO
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# From [1]
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HUFFMAN_CODE_TABLE = """\
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( 0) |11111111|11000 1ff8 [13]
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( 1) |11111111|11111111|1011000 7fffd8 [23]
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( 2) |11111111|11111111|11111110|0010 fffffe2 [28]
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( 3) |11111111|11111111|11111110|0011 fffffe3 [28]
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( 4) |11111111|11111111|11111110|0100 fffffe4 [28]
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( 5) |11111111|11111111|11111110|0101 fffffe5 [28]
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( 6) |11111111|11111111|11111110|0110 fffffe6 [28]
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( 7) |11111111|11111111|11111110|0111 fffffe7 [28]
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( 8) |11111111|11111111|11111110|1000 fffffe8 [28]
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( 9) |11111111|11111111|11101010 ffffea [24]
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( 10) |11111111|11111111|11111111|111100 3ffffffc [30]
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( 11) |11111111|11111111|11111110|1001 fffffe9 [28]
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( 12) |11111111|11111111|11111110|1010 fffffea [28]
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( 13) |11111111|11111111|11111111|111101 3ffffffd [30]
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( 14) |11111111|11111111|11111110|1011 fffffeb [28]
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( 15) |11111111|11111111|11111110|1100 fffffec [28]
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( 16) |11111111|11111111|11111110|1101 fffffed [28]
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( 17) |11111111|11111111|11111110|1110 fffffee [28]
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( 18) |11111111|11111111|11111110|1111 fffffef [28]
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( 19) |11111111|11111111|11111111|0000 ffffff0 [28]
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( 20) |11111111|11111111|11111111|0001 ffffff1 [28]
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( 21) |11111111|11111111|11111111|0010 ffffff2 [28]
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( 22) |11111111|11111111|11111111|111110 3ffffffe [30]
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( 23) |11111111|11111111|11111111|0011 ffffff3 [28]
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( 24) |11111111|11111111|11111111|0100 ffffff4 [28]
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( 25) |11111111|11111111|11111111|0101 ffffff5 [28]
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( 26) |11111111|11111111|11111111|0110 ffffff6 [28]
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( 27) |11111111|11111111|11111111|0111 ffffff7 [28]
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( 28) |11111111|11111111|11111111|1000 ffffff8 [28]
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( 29) |11111111|11111111|11111111|1001 ffffff9 [28]
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( 30) |11111111|11111111|11111111|1010 ffffffa [28]
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( 31) |11111111|11111111|11111111|1011 ffffffb [28]
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' ' ( 32) |010100 14 [ 6]
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'!' ( 33) |11111110|00 3f8 [10]
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'"' ( 34) |11111110|01 3f9 [10]
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'#' ( 35) |11111111|1010 ffa [12]
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'$' ( 36) |11111111|11001 1ff9 [13]
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'%' ( 37) |010101 15 [ 6]
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'&' ( 38) |11111000 f8 [ 8]
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''' ( 39) |11111111|010 7fa [11]
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'(' ( 40) |11111110|10 3fa [10]
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')' ( 41) |11111110|11 3fb [10]
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'*' ( 42) |11111001 f9 [ 8]
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'+' ( 43) |11111111|011 7fb [11]
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',' ( 44) |11111010 fa [ 8]
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'-' ( 45) |010110 16 [ 6]
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'.' ( 46) |010111 17 [ 6]
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'/' ( 47) |011000 18 [ 6]
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'0' ( 48) |00000 0 [ 5]
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'1' ( 49) |00001 1 [ 5]
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'2' ( 50) |00010 2 [ 5]
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'3' ( 51) |011001 19 [ 6]
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'4' ( 52) |011010 1a [ 6]
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'5' ( 53) |011011 1b [ 6]
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'6' ( 54) |011100 1c [ 6]
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'7' ( 55) |011101 1d [ 6]
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'8' ( 56) |011110 1e [ 6]
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'9' ( 57) |011111 1f [ 6]
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':' ( 58) |1011100 5c [ 7]
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';' ( 59) |11111011 fb [ 8]
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'<' ( 60) |11111111|1111100 7ffc [15]
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'=' ( 61) |100000 20 [ 6]
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'>' ( 62) |11111111|1011 ffb [12]
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'?' ( 63) |11111111|00 3fc [10]
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'@' ( 64) |11111111|11010 1ffa [13]
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'A' ( 65) |100001 21 [ 6]
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'B' ( 66) |1011101 5d [ 7]
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'C' ( 67) |1011110 5e [ 7]
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'D' ( 68) |1011111 5f [ 7]
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'E' ( 69) |1100000 60 [ 7]
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'F' ( 70) |1100001 61 [ 7]
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'G' ( 71) |1100010 62 [ 7]
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'H' ( 72) |1100011 63 [ 7]
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'I' ( 73) |1100100 64 [ 7]
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'J' ( 74) |1100101 65 [ 7]
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'K' ( 75) |1100110 66 [ 7]
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'L' ( 76) |1100111 67 [ 7]
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'M' ( 77) |1101000 68 [ 7]
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'N' ( 78) |1101001 69 [ 7]
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'O' ( 79) |1101010 6a [ 7]
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'P' ( 80) |1101011 6b [ 7]
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'Q' ( 81) |1101100 6c [ 7]
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'R' ( 82) |1101101 6d [ 7]
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'S' ( 83) |1101110 6e [ 7]
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'T' ( 84) |1101111 6f [ 7]
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'U' ( 85) |1110000 70 [ 7]
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'V' ( 86) |1110001 71 [ 7]
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'W' ( 87) |1110010 72 [ 7]
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'X' ( 88) |11111100 fc [ 8]
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'Y' ( 89) |1110011 73 [ 7]
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'Z' ( 90) |11111101 fd [ 8]
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'[' ( 91) |11111111|11011 1ffb [13]
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'\' ( 92) |11111111|11111110|000 7fff0 [19]
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']' ( 93) |11111111|11100 1ffc [13]
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'^' ( 94) |11111111|111100 3ffc [14]
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'_' ( 95) |100010 22 [ 6]
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'`' ( 96) |11111111|1111101 7ffd [15]
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'a' ( 97) |00011 3 [ 5]
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'b' ( 98) |100011 23 [ 6]
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'c' ( 99) |00100 4 [ 5]
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'd' (100) |100100 24 [ 6]
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'e' (101) |00101 5 [ 5]
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'f' (102) |100101 25 [ 6]
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'g' (103) |100110 26 [ 6]
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'h' (104) |100111 27 [ 6]
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'i' (105) |00110 6 [ 5]
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'j' (106) |1110100 74 [ 7]
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'k' (107) |1110101 75 [ 7]
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'l' (108) |101000 28 [ 6]
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'm' (109) |101001 29 [ 6]
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'n' (110) |101010 2a [ 6]
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'o' (111) |00111 7 [ 5]
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'p' (112) |101011 2b [ 6]
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'q' (113) |1110110 76 [ 7]
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'r' (114) |101100 2c [ 6]
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's' (115) |01000 8 [ 5]
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't' (116) |01001 9 [ 5]
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'u' (117) |101101 2d [ 6]
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'v' (118) |1110111 77 [ 7]
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'w' (119) |1111000 78 [ 7]
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'x' (120) |1111001 79 [ 7]
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'y' (121) |1111010 7a [ 7]
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'z' (122) |1111011 7b [ 7]
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'{' (123) |11111111|1111110 7ffe [15]
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'|' (124) |11111111|100 7fc [11]
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'}' (125) |11111111|111101 3ffd [14]
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'~' (126) |11111111|11101 1ffd [13]
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(127) |11111111|11111111|11111111|1100 ffffffc [28]
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(128) |11111111|11111110|0110 fffe6 [20]
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(129) |11111111|11111111|010010 3fffd2 [22]
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(130) |11111111|11111110|0111 fffe7 [20]
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(131) |11111111|11111110|1000 fffe8 [20]
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(132) |11111111|11111111|010011 3fffd3 [22]
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(133) |11111111|11111111|010100 3fffd4 [22]
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(134) |11111111|11111111|010101 3fffd5 [22]
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(135) |11111111|11111111|1011001 7fffd9 [23]
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(136) |11111111|11111111|010110 3fffd6 [22]
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(137) |11111111|11111111|1011010 7fffda [23]
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(138) |11111111|11111111|1011011 7fffdb [23]
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(139) |11111111|11111111|1011100 7fffdc [23]
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(140) |11111111|11111111|1011101 7fffdd [23]
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(141) |11111111|11111111|1011110 7fffde [23]
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(142) |11111111|11111111|11101011 ffffeb [24]
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(143) |11111111|11111111|1011111 7fffdf [23]
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(144) |11111111|11111111|11101100 ffffec [24]
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(145) |11111111|11111111|11101101 ffffed [24]
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(146) |11111111|11111111|010111 3fffd7 [22]
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(147) |11111111|11111111|1100000 7fffe0 [23]
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(148) |11111111|11111111|11101110 ffffee [24]
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(149) |11111111|11111111|1100001 7fffe1 [23]
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(150) |11111111|11111111|1100010 7fffe2 [23]
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(151) |11111111|11111111|1100011 7fffe3 [23]
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(152) |11111111|11111111|1100100 7fffe4 [23]
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(153) |11111111|11111110|11100 1fffdc [21]
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(154) |11111111|11111111|011000 3fffd8 [22]
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(155) |11111111|11111111|1100101 7fffe5 [23]
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(156) |11111111|11111111|011001 3fffd9 [22]
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(157) |11111111|11111111|1100110 7fffe6 [23]
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(158) |11111111|11111111|1100111 7fffe7 [23]
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(159) |11111111|11111111|11101111 ffffef [24]
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(160) |11111111|11111111|011010 3fffda [22]
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(161) |11111111|11111110|11101 1fffdd [21]
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(162) |11111111|11111110|1001 fffe9 [20]
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(163) |11111111|11111111|011011 3fffdb [22]
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(164) |11111111|11111111|011100 3fffdc [22]
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(165) |11111111|11111111|1101000 7fffe8 [23]
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(166) |11111111|11111111|1101001 7fffe9 [23]
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(167) |11111111|11111110|11110 1fffde [21]
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(168) |11111111|11111111|1101010 7fffea [23]
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(169) |11111111|11111111|011101 3fffdd [22]
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(170) |11111111|11111111|011110 3fffde [22]
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(171) |11111111|11111111|11110000 fffff0 [24]
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(172) |11111111|11111110|11111 1fffdf [21]
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(173) |11111111|11111111|011111 3fffdf [22]
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(174) |11111111|11111111|1101011 7fffeb [23]
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(175) |11111111|11111111|1101100 7fffec [23]
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(176) |11111111|11111111|00000 1fffe0 [21]
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(177) |11111111|11111111|00001 1fffe1 [21]
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(178) |11111111|11111111|100000 3fffe0 [22]
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(179) |11111111|11111111|00010 1fffe2 [21]
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(180) |11111111|11111111|1101101 7fffed [23]
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(181) |11111111|11111111|100001 3fffe1 [22]
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(182) |11111111|11111111|1101110 7fffee [23]
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(183) |11111111|11111111|1101111 7fffef [23]
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(184) |11111111|11111110|1010 fffea [20]
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(185) |11111111|11111111|100010 3fffe2 [22]
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(186) |11111111|11111111|100011 3fffe3 [22]
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(187) |11111111|11111111|100100 3fffe4 [22]
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(188) |11111111|11111111|1110000 7ffff0 [23]
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(189) |11111111|11111111|100101 3fffe5 [22]
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(190) |11111111|11111111|100110 3fffe6 [22]
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(191) |11111111|11111111|1110001 7ffff1 [23]
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(192) |11111111|11111111|11111000|00 3ffffe0 [26]
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(193) |11111111|11111111|11111000|01 3ffffe1 [26]
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(194) |11111111|11111110|1011 fffeb [20]
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(195) |11111111|11111110|001 7fff1 [19]
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(196) |11111111|11111111|100111 3fffe7 [22]
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(197) |11111111|11111111|1110010 7ffff2 [23]
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(198) |11111111|11111111|101000 3fffe8 [22]
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(199) |11111111|11111111|11110110|0 1ffffec [25]
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(200) |11111111|11111111|11111000|10 3ffffe2 [26]
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(201) |11111111|11111111|11111000|11 3ffffe3 [26]
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(202) |11111111|11111111|11111001|00 3ffffe4 [26]
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(203) |11111111|11111111|11111011|110 7ffffde [27]
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(204) |11111111|11111111|11111011|111 7ffffdf [27]
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(205) |11111111|11111111|11111001|01 3ffffe5 [26]
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(206) |11111111|11111111|11110001 fffff1 [24]
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(207) |11111111|11111111|11110110|1 1ffffed [25]
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(208) |11111111|11111110|010 7fff2 [19]
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(209) |11111111|11111111|00011 1fffe3 [21]
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(210) |11111111|11111111|11111001|10 3ffffe6 [26]
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(211) |11111111|11111111|11111100|000 7ffffe0 [27]
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(212) |11111111|11111111|11111100|001 7ffffe1 [27]
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(213) |11111111|11111111|11111001|11 3ffffe7 [26]
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(214) |11111111|11111111|11111100|010 7ffffe2 [27]
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(215) |11111111|11111111|11110010 fffff2 [24]
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(216) |11111111|11111111|00100 1fffe4 [21]
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(217) |11111111|11111111|00101 1fffe5 [21]
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(218) |11111111|11111111|11111010|00 3ffffe8 [26]
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(219) |11111111|11111111|11111010|01 3ffffe9 [26]
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(220) |11111111|11111111|11111111|1101 ffffffd [28]
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(221) |11111111|11111111|11111100|011 7ffffe3 [27]
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(222) |11111111|11111111|11111100|100 7ffffe4 [27]
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(223) |11111111|11111111|11111100|101 7ffffe5 [27]
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(224) |11111111|11111110|1100 fffec [20]
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(225) |11111111|11111111|11110011 fffff3 [24]
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(226) |11111111|11111110|1101 fffed [20]
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(227) |11111111|11111111|00110 1fffe6 [21]
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(228) |11111111|11111111|101001 3fffe9 [22]
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(229) |11111111|11111111|00111 1fffe7 [21]
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(230) |11111111|11111111|01000 1fffe8 [21]
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(231) |11111111|11111111|1110011 7ffff3 [23]
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(232) |11111111|11111111|101010 3fffea [22]
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(233) |11111111|11111111|101011 3fffeb [22]
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(234) |11111111|11111111|11110111|0 1ffffee [25]
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(235) |11111111|11111111|11110111|1 1ffffef [25]
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(236) |11111111|11111111|11110100 fffff4 [24]
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(237) |11111111|11111111|11110101 fffff5 [24]
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(238) |11111111|11111111|11111010|10 3ffffea [26]
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(239) |11111111|11111111|1110100 7ffff4 [23]
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(240) |11111111|11111111|11111010|11 3ffffeb [26]
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(241) |11111111|11111111|11111100|110 7ffffe6 [27]
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(242) |11111111|11111111|11111011|00 3ffffec [26]
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(243) |11111111|11111111|11111011|01 3ffffed [26]
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(244) |11111111|11111111|11111100|111 7ffffe7 [27]
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(245) |11111111|11111111|11111101|000 7ffffe8 [27]
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(246) |11111111|11111111|11111101|001 7ffffe9 [27]
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(247) |11111111|11111111|11111101|010 7ffffea [27]
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(248) |11111111|11111111|11111101|011 7ffffeb [27]
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(249) |11111111|11111111|11111111|1110 ffffffe [28]
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(250) |11111111|11111111|11111101|100 7ffffec [27]
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(251) |11111111|11111111|11111101|101 7ffffed [27]
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(252) |11111111|11111111|11111101|110 7ffffee [27]
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(253) |11111111|11111111|11111101|111 7ffffef [27]
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(254) |11111111|11111111|11111110|000 7fffff0 [27]
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(255) |11111111|11111111|11111011|10 3ffffee [26]
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EOS (256) |11111111|11111111|11111111|111111 3fffffff [30]
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"""
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class Node:
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def __init__(self, term = None):
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self.term = term
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self.left = None
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self.right = None
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self.trans = []
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self.id = None
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self.accept = False
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class Context:
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def __init__(self):
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self.next_id_ = 0
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self.root = Node()
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def next_id(self):
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id = self.next_id_
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self.next_id_ += 1
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return id
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def _add(node, sym, bits):
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if len(bits) == 0:
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node.term = sym
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return
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else:
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if bits[0] == '0':
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if node.left is None:
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node.left = Node()
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child = node.left
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else:
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if node.right is None:
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node.right = Node()
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child = node.right
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_add(child, sym, bits[1:])
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def huffman_tree_add(ctx, sym, bits):
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_add(ctx.root, sym, bits)
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def _set_node_id(ctx, node, prefix):
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if node.term is not None:
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return
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if len(prefix) <= 7 and [1] * len(prefix) == prefix:
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node.accept = True
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node.id = ctx.next_id()
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_set_node_id(ctx, node.left, prefix + [0])
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_set_node_id(ctx, node.right, prefix + [1])
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def huffman_tree_set_node_id(ctx):
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_set_node_id(ctx, ctx.root, [])
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def _traverse(node, sym, start_node, root, left):
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if left == 0:
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if sym == 256:
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sym = None
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node = None
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start_node.trans.append((node, sym))
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return
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if node.term is not None:
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node = root
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def go(node):
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if node.term is not None:
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assert sym is None
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nsym = node.term
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else:
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nsym = sym
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_traverse(node, nsym, start_node, root, left - 1)
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go(node.left)
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go(node.right)
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def _build_transition_table(ctx, node):
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if node is None:
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return
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_traverse(node, None, node, ctx.root, 4)
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_build_transition_table(ctx, node.left)
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_build_transition_table(ctx, node.right)
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def huffman_tree_build_transition_table(ctx):
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_build_transition_table(ctx, ctx.root)
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NGHTTP2_HUFF_ACCEPTED = 1
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NGHTTP2_HUFF_SYM = 1 << 1
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NGHTTP2_HUFF_FAIL = 1 << 2
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def _print_transition_table(node):
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if node.term is not None:
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return
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print '/* {} */'.format(node.id)
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print '{'
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for nd, sym in node.trans:
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flags = 0
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if sym is None:
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out = 0
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else:
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out = sym
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flags |= NGHTTP2_HUFF_SYM
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if nd is None:
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id = 0
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flags |= NGHTTP2_HUFF_FAIL
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else:
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id = nd.id
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if id is None:
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# if nd.id is None, it is a leaf node
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id = 0
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flags |= NGHTTP2_HUFF_ACCEPTED
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elif nd.accept:
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flags |= NGHTTP2_HUFF_ACCEPTED
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print ' {{{}, 0x{:02x}, {}}},'.format(id, flags, out)
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print '},'
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_print_transition_table(node.left)
|
|
_print_transition_table(node.right)
|
|
|
|
def huffman_tree_print_transition_table(ctx):
|
|
_print_transition_table(ctx.root)
|
|
|
|
if __name__ == '__main__':
|
|
ctx = Context()
|
|
symbol_tbl = [(None, 0) for i in range(257)]
|
|
|
|
for line in StringIO.StringIO(HUFFMAN_CODE_TABLE):
|
|
m = re.match(
|
|
r'.*\(\s*(\d+)\)\s+([|01]+)\s+(\S+)\s+\[\s*(\d+)\].*', line)
|
|
if m:
|
|
sym = int(m.group(1))
|
|
bits = re.sub(r'\|', '', m.group(2))
|
|
code = m.group(3)
|
|
nbits = int(m.group(4))
|
|
if len(code) > 8:
|
|
raise Error('Code is more than 4 bytes long')
|
|
assert(len(bits) == nbits)
|
|
symbol_tbl[sym] = (nbits, code)
|
|
huffman_tree_add(ctx, sym, bits)
|
|
|
|
huffman_tree_set_node_id(ctx)
|
|
huffman_tree_build_transition_table(ctx)
|
|
|
|
print '''\
|
|
typedef struct {
|
|
uint32_t nbits;
|
|
uint32_t code;
|
|
} nghttp2_huff_sym;
|
|
'''
|
|
|
|
print '''\
|
|
const nghttp2_huff_sym huff_sym_table[] = {'''
|
|
for i in range(257):
|
|
print '''\
|
|
{{ {}, 0x{}u }}{}\
|
|
'''.format(symbol_tbl[i][0], symbol_tbl[i][1], ',' if i < 256 else '')
|
|
print '};'
|
|
print ''
|
|
|
|
print '''\
|
|
enum {{
|
|
NGHTTP2_HUFF_ACCEPTED = {},
|
|
NGHTTP2_HUFF_SYM = {},
|
|
NGHTTP2_HUFF_FAIL = {},
|
|
}} nghttp2_huff_decode_flag;
|
|
'''.format(NGHTTP2_HUFF_ACCEPTED, NGHTTP2_HUFF_SYM, NGHTTP2_HUFF_FAIL)
|
|
|
|
print '''\
|
|
typedef struct {
|
|
uint8_t state;
|
|
uint8_t flags;
|
|
uint8_t sym;
|
|
} nghttp2_huff_decode;
|
|
'''
|
|
|
|
print '''\
|
|
const nghttp2_huff_decode huff_decode_table[][16] = {'''
|
|
huffman_tree_print_transition_table(ctx)
|
|
print '};'
|