The Tor Browser: netwerk/protocol/http/make_incoming

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 # This script exists to auto-generate Http2HuffmanIncoming.h from the table

     2 # contained in the HPACK spec. It's pretty simple to run:

     3 #   python make_incoming_tables.py < http2_huffman_table.txt > Http2HuffmanIncoming.h

     4 # where huff_incoming.txt is copy/pasted text from the latest version of the

     5 # HPACK spec, with all non-relevant lines removed (the most recent version

     6 # of huff_incoming.txt also lives in this directory as an example).

     7 import sys

     9 def char_cmp(x, y):

    10     rv = cmp(x['nbits'], y['nbits'])

    11     if not rv:

    12         rv = cmp(x['bpat'], y['bpat'])

    13     if not rv:

    14         rv = cmp(x['ascii'], y['ascii'])

    15     return rv

    17 characters = []

    19 for line in sys.stdin:

    20     line = line.rstrip()

    21     obracket = line.rfind('[')

    22     nbits = int(line[obracket + 1:-1])

    24     ascii = int(line[10:13].strip())

    26     bar = line.find('|', 9)

    27     obracket = line.find('[', bar)

    28     bpat = line[bar + 1:obracket - 1].strip().rstrip('|')

    30     characters.append({'ascii': ascii, 'nbits': nbits, 'bpat': bpat})

    32 characters.sort(cmp=char_cmp)

    33 raw_entries = []

    34 for c in characters:

    35     raw_entries.append((c['ascii'], c['bpat']))

    37 class DefaultList(list):

    38     def __init__(self, default=None):

    39         self.__default = default

    41     def __ensure_size(self, sz):

    42         while sz > len(self):

    43             self.append(self.__default)

    45     def __getitem__(self, idx):

    46         self.__ensure_size(idx + 1)

    47         rv = super(DefaultList, self).__getitem__(idx)

    48         return rv

    50     def __setitem__(self, idx, val):

    51         self.__ensure_size(idx + 1)

    52         super(DefaultList, self).__setitem__(idx, val)

    54 def expand_to_8bit(bstr):

    55     while len(bstr) < 8:

    56         bstr += '0'

    57     return int(bstr, 2)

    59 table = DefaultList()

    60 for r in raw_entries:

    61     ascii, bpat = r

    62     ascii = int(ascii)

    63     bstrs = bpat.split('|')

    64     curr_table = table

    65     while len(bstrs) > 1:

    66         idx = expand_to_8bit(bstrs[0])

    67         if curr_table[idx] is None:

    68             curr_table[idx] = DefaultList()

    69         curr_table = curr_table[idx]

    70         bstrs.pop(0)

    72     idx = expand_to_8bit(bstrs[0])

    73     curr_table[idx] = {'prefix_len': len(bstrs[0]),

    74                         'mask': int(bstrs[0], 2),

    75                         'value': ascii}

    78 def output_table(table, name_suffix=''):

    79     max_prefix_len = 0

    80     for i, t in enumerate(table):

    81         if isinstance(t, dict):

    82             if t['prefix_len'] > max_prefix_len:

    83                 max_prefix_len = t['prefix_len']

    84         elif t is not None:

    85             output_table(t, '%s_%s' % (name_suffix, i))

    87     tablename = 'HuffmanIncoming%s' % (name_suffix if name_suffix else 'Root',)

    88     entriestable = tablename.replace('HuffmanIncoming', 'HuffmanIncomingEntries')

    89     sys.stdout.write('static HuffmanIncomingEntry %s[] = {\n' % (entriestable,))

    90     prefix_len = 0

    91     value = 0

    92     ptr = 'nullptr'

    93     for i in range(256):

    94         t = table[i]

    95         if isinstance(t, dict):

    96             prefix_len = t['prefix_len']

    97             value = t['value']

    98             ptr = 'nullptr'

    99         elif t is not None:

   100             prefix_len = 0

   101             value = 0

   102             subtable = '%s_%s' % (name_suffix, i)

   103             ptr = '&HuffmanIncoming%s' % (subtable,)

   104         sys.stdout.write('  { %s, %s, %s }' %

   105                          (ptr, value, prefix_len))

   106         if i < 255:

   107             sys.stdout.write(',')

   108         sys.stdout.write('\n')

   109     sys.stdout.write('};\n')

   110     sys.stdout.write('\n')

   111     sys.stdout.write('static HuffmanIncomingTable %s = {\n' % (tablename,))

   112     sys.stdout.write('  %s,\n' % (entriestable,))

   113     sys.stdout.write('  %s\n' % (max_prefix_len,))

   114     sys.stdout.write('};\n')

   115     sys.stdout.write('\n')

   117 sys.stdout.write('''/*

   118  * THIS FILE IS AUTO-GENERATED. DO NOT EDIT!

   119  */

   120 #ifndef mozilla__net__Http2HuffmanIncoming_h

   121 #define mozilla__net__Http2HuffmanIncoming_h

   123 namespace mozilla {

   124 namespace net {

   126 struct HuffmanIncomingTable;

   128 struct HuffmanIncomingEntry {

   129   HuffmanIncomingTable *mPtr;

   130   uint16_t mValue;

   131   uint8_t mPrefixLen;

   132 };

   134 struct HuffmanIncomingTable {

   135   HuffmanIncomingEntry *mEntries;

   136   uint8_t mPrefixLen;

   137 };

   139 ''')

   141 output_table(table)

   143 sys.stdout.write('''} // namespace net

   144 } // namespace mozilla

   146 #endif // mozilla__net__Http2HuffmanIncoming_h

   147 ''')

The Tor Browser / file revision