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nghttp2/mkhufftbl.py

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Add auto-generation tools
2013-10-15 18:23:10 +02:00
#!/usr/bin/env python
mkhufftbl.py: Update doc
2014-10-24 18:08:57 +02:00
# -*- coding: utf-8 -*-
# This script reads Huffman Code table [1] and generates symbol table
# and decoding tables in C language. The resulting code is used in
# lib/nghttp2_hd_huffman.h and lib/nghttp2_hd_huffman_data.c
#
# [1] http://http2.github.io/http2-spec/compression.html
from __future__ import unicode_literals
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import re
import sys
mkhufftbl.py: Refactor
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import StringIO
# From [1]
HUFFMAN_CODE_TABLE = """\
( 0) |11111111|11000 1ff8 [13]
( 1) |11111111|11111111|1011000 7fffd8 [23]
( 2) |11111111|11111111|11111110|0010 fffffe2 [28]
( 3) |11111111|11111111|11111110|0011 fffffe3 [28]
( 4) |11111111|11111111|11111110|0100 fffffe4 [28]
( 5) |11111111|11111111|11111110|0101 fffffe5 [28]
( 6) |11111111|11111111|11111110|0110 fffffe6 [28]
( 7) |11111111|11111111|11111110|0111 fffffe7 [28]
( 8) |11111111|11111111|11111110|1000 fffffe8 [28]
( 9) |11111111|11111111|11101010 ffffea [24]
( 10) |11111111|11111111|11111111|111100 3ffffffc [30]
( 11) |11111111|11111111|11111110|1001 fffffe9 [28]
( 12) |11111111|11111111|11111110|1010 fffffea [28]
( 13) |11111111|11111111|11111111|111101 3ffffffd [30]
( 14) |11111111|11111111|11111110|1011 fffffeb [28]
( 15) |11111111|11111111|11111110|1100 fffffec [28]
( 16) |11111111|11111111|11111110|1101 fffffed [28]
( 17) |11111111|11111111|11111110|1110 fffffee [28]
( 18) |11111111|11111111|11111110|1111 fffffef [28]
( 19) |11111111|11111111|11111111|0000 ffffff0 [28]
( 20) |11111111|11111111|11111111|0001 ffffff1 [28]
( 21) |11111111|11111111|11111111|0010 ffffff2 [28]
( 22) |11111111|11111111|11111111|111110 3ffffffe [30]
( 23) |11111111|11111111|11111111|0011 ffffff3 [28]
( 24) |11111111|11111111|11111111|0100 ffffff4 [28]
( 25) |11111111|11111111|11111111|0101 ffffff5 [28]
( 26) |11111111|11111111|11111111|0110 ffffff6 [28]
( 27) |11111111|11111111|11111111|0111 ffffff7 [28]
( 28) |11111111|11111111|11111111|1000 ffffff8 [28]
( 29) |11111111|11111111|11111111|1001 ffffff9 [28]
( 30) |11111111|11111111|11111111|1010 ffffffa [28]
( 31) |11111111|11111111|11111111|1011 ffffffb [28]
' ' ( 32) |010100 14 [ 6]
'!' ( 33) |11111110|00 3f8 [10]
'"' ( 34) |11111110|01 3f9 [10]
'#' ( 35) |11111111|1010 ffa [12]
'$' ( 36) |11111111|11001 1ff9 [13]
'%' ( 37) |010101 15 [ 6]
'&' ( 38) |11111000 f8 [ 8]
''' ( 39) |11111111|010 7fa [11]
'(' ( 40) |11111110|10 3fa [10]
')' ( 41) |11111110|11 3fb [10]
'*' ( 42) |11111001 f9 [ 8]
'+' ( 43) |11111111|011 7fb [11]
',' ( 44) |11111010 fa [ 8]
'-' ( 45) |010110 16 [ 6]
'.' ( 46) |010111 17 [ 6]
'/' ( 47) |011000 18 [ 6]
'0' ( 48) |00000 0 [ 5]
'1' ( 49) |00001 1 [ 5]
'2' ( 50) |00010 2 [ 5]
'3' ( 51) |011001 19 [ 6]
'4' ( 52) |011010 1a [ 6]
'5' ( 53) |011011 1b [ 6]
'6' ( 54) |011100 1c [ 6]
'7' ( 55) |011101 1d [ 6]
'8' ( 56) |011110 1e [ 6]
'9' ( 57) |011111 1f [ 6]
':' ( 58) |1011100 5c [ 7]
';' ( 59) |11111011 fb [ 8]
'<' ( 60) |11111111|1111100 7ffc [15]
'=' ( 61) |100000 20 [ 6]
'>' ( 62) |11111111|1011 ffb [12]
'?' ( 63) |11111111|00 3fc [10]
'@' ( 64) |11111111|11010 1ffa [13]
'A' ( 65) |100001 21 [ 6]
'B' ( 66) |1011101 5d [ 7]
'C' ( 67) |1011110 5e [ 7]
'D' ( 68) |1011111 5f [ 7]
'E' ( 69) |1100000 60 [ 7]
'F' ( 70) |1100001 61 [ 7]
'G' ( 71) |1100010 62 [ 7]
'H' ( 72) |1100011 63 [ 7]
'I' ( 73) |1100100 64 [ 7]
'J' ( 74) |1100101 65 [ 7]
'K' ( 75) |1100110 66 [ 7]
'L' ( 76) |1100111 67 [ 7]
'M' ( 77) |1101000 68 [ 7]
'N' ( 78) |1101001 69 [ 7]
'O' ( 79) |1101010 6a [ 7]
'P' ( 80) |1101011 6b [ 7]
'Q' ( 81) |1101100 6c [ 7]
'R' ( 82) |1101101 6d [ 7]
'S' ( 83) |1101110 6e [ 7]
'T' ( 84) |1101111 6f [ 7]
'U' ( 85) |1110000 70 [ 7]
'V' ( 86) |1110001 71 [ 7]
'W' ( 87) |1110010 72 [ 7]
'X' ( 88) |11111100 fc [ 8]
'Y' ( 89) |1110011 73 [ 7]
'Z' ( 90) |11111101 fd [ 8]
'[' ( 91) |11111111|11011 1ffb [13]
'\' ( 92) |11111111|11111110|000 7fff0 [19]
']' ( 93) |11111111|11100 1ffc [13]
'^' ( 94) |11111111|111100 3ffc [14]
'_' ( 95) |100010 22 [ 6]
'`' ( 96) |11111111|1111101 7ffd [15]
'a' ( 97) |00011 3 [ 5]
'b' ( 98) |100011 23 [ 6]
'c' ( 99) |00100 4 [ 5]
'd' (100) |100100 24 [ 6]
'e' (101) |00101 5 [ 5]
'f' (102) |100101 25 [ 6]
'g' (103) |100110 26 [ 6]
'h' (104) |100111 27 [ 6]
'i' (105) |00110 6 [ 5]
'j' (106) |1110100 74 [ 7]
'k' (107) |1110101 75 [ 7]
'l' (108) |101000 28 [ 6]
'm' (109) |101001 29 [ 6]
'n' (110) |101010 2a [ 6]
'o' (111) |00111 7 [ 5]
'p' (112) |101011 2b [ 6]
'q' (113) |1110110 76 [ 7]
'r' (114) |101100 2c [ 6]
's' (115) |01000 8 [ 5]
't' (116) |01001 9 [ 5]
'u' (117) |101101 2d [ 6]
'v' (118) |1110111 77 [ 7]
'w' (119) |1111000 78 [ 7]
'x' (120) |1111001 79 [ 7]
'y' (121) |1111010 7a [ 7]
'z' (122) |1111011 7b [ 7]
'{' (123) |11111111|1111110 7ffe [15]
'|' (124) |11111111|100 7fc [11]
'}' (125) |11111111|111101 3ffd [14]
'~' (126) |11111111|11101 1ffd [13]
(127) |11111111|11111111|11111111|1100 ffffffc [28]
(128) |11111111|11111110|0110 fffe6 [20]
(129) |11111111|11111111|010010 3fffd2 [22]
(130) |11111111|11111110|0111 fffe7 [20]
(131) |11111111|11111110|1000 fffe8 [20]
(132) |11111111|11111111|010011 3fffd3 [22]
(133) |11111111|11111111|010100 3fffd4 [22]
(134) |11111111|11111111|010101 3fffd5 [22]
(135) |11111111|11111111|1011001 7fffd9 [23]
(136) |11111111|11111111|010110 3fffd6 [22]
(137) |11111111|11111111|1011010 7fffda [23]
(138) |11111111|11111111|1011011 7fffdb [23]
(139) |11111111|11111111|1011100 7fffdc [23]
(140) |11111111|11111111|1011101 7fffdd [23]
(141) |11111111|11111111|1011110 7fffde [23]
(142) |11111111|11111111|11101011 ffffeb [24]
(143) |11111111|11111111|1011111 7fffdf [23]
(144) |11111111|11111111|11101100 ffffec [24]
(145) |11111111|11111111|11101101 ffffed [24]
(146) |11111111|11111111|010111 3fffd7 [22]
(147) |11111111|11111111|1100000 7fffe0 [23]
(148) |11111111|11111111|11101110 ffffee [24]
(149) |11111111|11111111|1100001 7fffe1 [23]
(150) |11111111|11111111|1100010 7fffe2 [23]
(151) |11111111|11111111|1100011 7fffe3 [23]
(152) |11111111|11111111|1100100 7fffe4 [23]
(153) |11111111|11111110|11100 1fffdc [21]
(154) |11111111|11111111|011000 3fffd8 [22]
(155) |11111111|11111111|1100101 7fffe5 [23]
(156) |11111111|11111111|011001 3fffd9 [22]
(157) |11111111|11111111|1100110 7fffe6 [23]
(158) |11111111|11111111|1100111 7fffe7 [23]
(159) |11111111|11111111|11101111 ffffef [24]
(160) |11111111|11111111|011010 3fffda [22]
(161) |11111111|11111110|11101 1fffdd [21]
(162) |11111111|11111110|1001 fffe9 [20]
(163) |11111111|11111111|011011 3fffdb [22]
(164) |11111111|11111111|011100 3fffdc [22]
(165) |11111111|11111111|1101000 7fffe8 [23]
(166) |11111111|11111111|1101001 7fffe9 [23]
(167) |11111111|11111110|11110 1fffde [21]
(168) |11111111|11111111|1101010 7fffea [23]
(169) |11111111|11111111|011101 3fffdd [22]
(170) |11111111|11111111|011110 3fffde [22]
(171) |11111111|11111111|11110000 fffff0 [24]
(172) |11111111|11111110|11111 1fffdf [21]
(173) |11111111|11111111|011111 3fffdf [22]
(174) |11111111|11111111|1101011 7fffeb [23]
(175) |11111111|11111111|1101100 7fffec [23]
(176) |11111111|11111111|00000 1fffe0 [21]
(177) |11111111|11111111|00001 1fffe1 [21]
(178) |11111111|11111111|100000 3fffe0 [22]
(179) |11111111|11111111|00010 1fffe2 [21]
(180) |11111111|11111111|1101101 7fffed [23]
(181) |11111111|11111111|100001 3fffe1 [22]
(182) |11111111|11111111|1101110 7fffee [23]
(183) |11111111|11111111|1101111 7fffef [23]
(184) |11111111|11111110|1010 fffea [20]
(185) |11111111|11111111|100010 3fffe2 [22]
(186) |11111111|11111111|100011 3fffe3 [22]
(187) |11111111|11111111|100100 3fffe4 [22]
(188) |11111111|11111111|1110000 7ffff0 [23]
(189) |11111111|11111111|100101 3fffe5 [22]
(190) |11111111|11111111|100110 3fffe6 [22]
(191) |11111111|11111111|1110001 7ffff1 [23]
(192) |11111111|11111111|11111000|00 3ffffe0 [26]
(193) |11111111|11111111|11111000|01 3ffffe1 [26]
(194) |11111111|11111110|1011 fffeb [20]
(195) |11111111|11111110|001 7fff1 [19]
(196) |11111111|11111111|100111 3fffe7 [22]
(197) |11111111|11111111|1110010 7ffff2 [23]
(198) |11111111|11111111|101000 3fffe8 [22]
(199) |11111111|11111111|11110110|0 1ffffec [25]
(200) |11111111|11111111|11111000|10 3ffffe2 [26]
(201) |11111111|11111111|11111000|11 3ffffe3 [26]
(202) |11111111|11111111|11111001|00 3ffffe4 [26]
(203) |11111111|11111111|11111011|110 7ffffde [27]
(204) |11111111|11111111|11111011|111 7ffffdf [27]
(205) |11111111|11111111|11111001|01 3ffffe5 [26]
(206) |11111111|11111111|11110001 fffff1 [24]
(207) |11111111|11111111|11110110|1 1ffffed [25]
(208) |11111111|11111110|010 7fff2 [19]
(209) |11111111|11111111|00011 1fffe3 [21]
(210) |11111111|11111111|11111001|10 3ffffe6 [26]
(211) |11111111|11111111|11111100|000 7ffffe0 [27]
(212) |11111111|11111111|11111100|001 7ffffe1 [27]
(213) |11111111|11111111|11111001|11 3ffffe7 [26]
(214) |11111111|11111111|11111100|010 7ffffe2 [27]
(215) |11111111|11111111|11110010 fffff2 [24]
(216) |11111111|11111111|00100 1fffe4 [21]
(217) |11111111|11111111|00101 1fffe5 [21]
(218) |11111111|11111111|11111010|00 3ffffe8 [26]
(219) |11111111|11111111|11111010|01 3ffffe9 [26]
(220) |11111111|11111111|11111111|1101 ffffffd [28]
(221) |11111111|11111111|11111100|011 7ffffe3 [27]
(222) |11111111|11111111|11111100|100 7ffffe4 [27]
(223) |11111111|11111111|11111100|101 7ffffe5 [27]
(224) |11111111|11111110|1100 fffec [20]
(225) |11111111|11111111|11110011 fffff3 [24]
(226) |11111111|11111110|1101 fffed [20]
(227) |11111111|11111111|00110 1fffe6 [21]
(228) |11111111|11111111|101001 3fffe9 [22]
(229) |11111111|11111111|00111 1fffe7 [21]
(230) |11111111|11111111|01000 1fffe8 [21]
(231) |11111111|11111111|1110011 7ffff3 [23]
(232) |11111111|11111111|101010 3fffea [22]
(233) |11111111|11111111|101011 3fffeb [22]
(234) |11111111|11111111|11110111|0 1ffffee [25]
(235) |11111111|11111111|11110111|1 1ffffef [25]
(236) |11111111|11111111|11110100 fffff4 [24]
(237) |11111111|11111111|11110101 fffff5 [24]
(238) |11111111|11111111|11111010|10 3ffffea [26]
(239) |11111111|11111111|1110100 7ffff4 [23]
(240) |11111111|11111111|11111010|11 3ffffeb [26]
(241) |11111111|11111111|11111100|110 7ffffe6 [27]
(242) |11111111|11111111|11111011|00 3ffffec [26]
(243) |11111111|11111111|11111011|01 3ffffed [26]
(244) |11111111|11111111|11111100|111 7ffffe7 [27]
(245) |11111111|11111111|11111101|000 7ffffe8 [27]
(246) |11111111|11111111|11111101|001 7ffffe9 [27]
(247) |11111111|11111111|11111101|010 7ffffea [27]
(248) |11111111|11111111|11111101|011 7ffffeb [27]
(249) |11111111|11111111|11111111|1110 ffffffe [28]
(250) |11111111|11111111|11111101|100 7ffffec [27]
(251) |11111111|11111111|11111101|101 7ffffed [27]
(252) |11111111|11111111|11111101|110 7ffffee [27]
(253) |11111111|11111111|11111101|111 7ffffef [27]
(254) |11111111|11111111|11111110|000 7fffff0 [27]
(255) |11111111|11111111|11111011|10 3ffffee [26]
EOS (256) |11111111|11111111|11111111|111111 3fffffff [30]
"""
Add auto-generation tools
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class Node:
mkhufftbl.py: Refactor
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nghttp2_hd: Rewrite huffman decoding
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def __init__(self, term = None):
self.term = term
self.left = None
self.right = None
self.trans = []
self.id = None
self.accept = False
Add auto-generation tools
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mkhufftbl.py: Refactor
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class Context:
def __init__(self):
self.next_id_ = 0
self.root = Node()
def next_id(self):
id = self.next_id_
self.next_id_ += 1
return id
def _add(node, sym, bits):
nghttp2_hd: Rewrite huffman decoding
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if len(bits) == 0:
node.term = sym
return
Add auto-generation tools
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else:
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if bits[0] == '0':
if node.left is None:
node.left = Node()
child = node.left
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else:
nghttp2_hd: Rewrite huffman decoding
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if node.right is None:
node.right = Node()
child = node.right
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_add(child, sym, bits[1:])
def huffman_tree_add(ctx, sym, bits):
_add(ctx.root, sym, bits)
nghttp2_hd: Rewrite huffman decoding
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mkhufftbl.py: Refactor
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def _set_node_id(ctx, node, prefix):
if node.term is not None:
return
if len(prefix) <= 7 and [1] * len(prefix) == prefix:
node.accept = True
node.id = ctx.next_id()
_set_node_id(ctx, node.left, prefix + [0])
_set_node_id(ctx, node.right, prefix + [1])
def huffman_tree_set_node_id(ctx):
_set_node_id(ctx, ctx.root, [])
def _traverse(node, sym, start_node, root, left):
if left == 0:
if sym == 256:
sym = None
nghttp2_hd: Rewrite huffman decoding
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node = None
mkhufftbl.py: Refactor
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start_node.trans.append((node, sym))
nghttp2_hd: Rewrite huffman decoding
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return
if node.term is not None:
node = root
mkhufftbl.py: Refactor
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def go(node):
nghttp2_hd: Rewrite huffman decoding
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if node.term is not None:
mkhufftbl.py: Refactor
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assert sym is None
nsym = node.term
else:
nsym = sym
nghttp2_hd: Rewrite huffman decoding
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mkhufftbl.py: Refactor
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_traverse(node, nsym, start_node, root, left - 1)
nghttp2_hd: Rewrite huffman decoding
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mkhufftbl.py: Refactor
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go(node.left)
go(node.right)
nghttp2_hd: Rewrite huffman decoding
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mkhufftbl.py: Refactor
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def _build_transition_table(ctx, node):
nghttp2_hd: Rewrite huffman decoding
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if node is None:
return
mkhufftbl.py: Refactor
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_traverse(node, None, node, ctx.root, 4)
_build_transition_table(ctx, node.left)
_build_transition_table(ctx, node.right)
def huffman_tree_build_transition_table(ctx):
_build_transition_table(ctx, ctx.root)
nghttp2_hd: Rewrite huffman decoding
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Faster huffman decoding
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NGHTTP2_HUFF_ACCEPTED = 1 << 14
NGHTTP2_HUFF_SYM = 1 << 15
nghttp2_hd: Rewrite huffman decoding
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mkhufftbl.py: Refactor
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def _print_transition_table(node):
nghttp2_hd: Rewrite huffman decoding
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if node.term is not None:
return
print '/* {} */'.format(node.id)
print '{'
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for nd, sym in node.trans:
nghttp2_hd: Rewrite huffman decoding
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flags = 0
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if sym is None:
nghttp2_hd: Rewrite huffman decoding
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out = 0
else:
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out = sym
nghttp2_hd: Rewrite huffman decoding
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flags |= NGHTTP2_HUFF_SYM
if nd is None:
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id = 256
nghttp2_hd: Rewrite huffman decoding
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else:
id = nd.id
if id is None:
# if nd.id is None, it is a leaf node
id = 0
flags |= NGHTTP2_HUFF_ACCEPTED
elif nd.accept:
flags |= NGHTTP2_HUFF_ACCEPTED
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print ' {{0x{:02x}, {}}},'.format(id | flags, out)
nghttp2_hd: Rewrite huffman decoding
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print '},'
mkhufftbl.py: Refactor
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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)
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print '/* 256 */'
print '{'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print ' {0x100, 0},'
print '},'
mkhufftbl.py: Refactor
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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 '''\
Add auto-generation tools
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typedef struct {
nghttp2_hd: Simplify huffman encode
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uint32_t nbits;
uint32_t code;
Add auto-generation tools
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} nghttp2_huff_sym;
'''
print '''\
mkhufftbl.py: Refactor
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const nghttp2_huff_sym huff_sym_table[] = {'''
for i in range(257):
Faster huffman encoding
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nbits = symbol_tbl[i][0]
k = int(symbol_tbl[i][1], 16)
k = k << (32 - nbits)
mkhufftbl.py: Refactor
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print '''\
nghttp2_hd: Simplify huffman encode
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{{ {}, 0x{}u }}{}\
Faster huffman encoding
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'''.format(symbol_tbl[i][0], hex(k)[2:], ',' if i < 256 else '')
mkhufftbl.py: Refactor
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print '};'
print ''
Add auto-generation tools
2013-10-15 18:23:10 +02:00
mkhufftbl.py: Refactor
2015-04-21 16:48:45 +02:00
print '''\
nghttp2_hd: Rewrite huffman decoding
2014-01-24 13:56:19 +01:00
enum {{
NGHTTP2_HUFF_ACCEPTED = {},
Reduce huffman decoding table Previously we have uint16_t as state member variable in nghttp2_huff_decode structure to express -1 as failure. This is because we have 256 valid states. However, we can express failed state using flags member variable and make state uint8_t. This commit does this and as a result the size of decoding table is reduced.
2014-05-30 17:19:30 +02:00
NGHTTP2_HUFF_SYM = {},
nghttp2_hd: Rewrite huffman decoding
2014-01-24 13:56:19 +01:00
}} nghttp2_huff_decode_flag;
Faster huffman decoding
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'''.format(NGHTTP2_HUFF_ACCEPTED, NGHTTP2_HUFF_SYM)
nghttp2_hd: Rewrite huffman decoding
2014-01-24 13:56:19 +01:00
mkhufftbl.py: Refactor
2015-04-21 16:48:45 +02:00
print '''\
nghttp2_hd: Rewrite huffman decoding
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typedef struct {
Faster huffman decoding
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uint16_t fstate;
nghttp2_hd: Rewrite huffman decoding
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uint8_t sym;
} nghttp2_huff_decode;
'''
mkhufftbl.py: Refactor
2015-04-21 16:48:45 +02:00
print '''\
nghttp2_hd: Rewrite huffman decoding
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const nghttp2_huff_decode huff_decode_table[][16] = {'''
mkhufftbl.py: Refactor
2015-04-21 16:48:45 +02:00
huffman_tree_print_transition_table(ctx)
print '};'