Mercurial > public > mercurial-scm > hg-stable

annotate mercurial/utils/cborutil.py @ 39440:babad5ebaf0a

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
cborutil: add a buffering decoder The sansiodecoder leaves it up to the callers to feed in data that wasn't fully consumed last time. This commit implements a decoder that performs buffering of leftover chunks from the previous invocation. It otherwise behaves identically to sansiodecoder. Differential Revision: https://phab.mercurial-scm.org/D4434
author Gregory Szorc <gregory.szorc@gmail.com>
date Wed, 29 Aug 2018 14:29:01 -0700
parents a40d3da89b7d
children 8d858fbf2759
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
37711
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
1 # cborutil.py - CBOR extensions
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
2 #
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
3 # Copyright 2018 Gregory Szorc <gregory.szorc@gmail.com>
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
4 #
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
5 # This software may be used and distributed according to the terms of the
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
6 # GNU General Public License version 2 or any later version.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
7
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
8 from __future__ import absolute_import
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
9
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
10 import struct
39438
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
11 import sys
37711
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
12
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
13 # Very short very of RFC 7049...
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
14 #
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
15 # Each item begins with a byte. The 3 high bits of that byte denote the
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
16 # "major type." The lower 5 bits denote the "subtype." Each major type
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
17 # has its own encoding mechanism.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
18 #
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
19 # Most types have lengths. However, bytestring, string, array, and map
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
20 # can be indefinite length. These are denotes by a subtype with value 31.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
21 # Sub-components of those types then come afterwards and are terminated
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
22 # by a "break" byte.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
23
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
24 MAJOR_TYPE_UINT = 0
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
25 MAJOR_TYPE_NEGINT = 1
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
26 MAJOR_TYPE_BYTESTRING = 2
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
27 MAJOR_TYPE_STRING = 3
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
28 MAJOR_TYPE_ARRAY = 4
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
29 MAJOR_TYPE_MAP = 5
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
30 MAJOR_TYPE_SEMANTIC = 6
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
31 MAJOR_TYPE_SPECIAL = 7
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
32
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
33 SUBTYPE_MASK = 0b00011111
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
34
39438
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
35 SUBTYPE_FALSE = 20
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
36 SUBTYPE_TRUE = 21
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
37 SUBTYPE_NULL = 22
37711
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
38 SUBTYPE_HALF_FLOAT = 25
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
39 SUBTYPE_SINGLE_FLOAT = 26
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
40 SUBTYPE_DOUBLE_FLOAT = 27
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
41 SUBTYPE_INDEFINITE = 31
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
42
39438
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
43 SEMANTIC_TAG_FINITE_SET = 258
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
44
37711
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
45 # Indefinite types begin with their major type ORd with information value 31.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
46 BEGIN_INDEFINITE_BYTESTRING = struct.pack(
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
47 r'>B', MAJOR_TYPE_BYTESTRING << 5 | SUBTYPE_INDEFINITE)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
48 BEGIN_INDEFINITE_ARRAY = struct.pack(
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
49 r'>B', MAJOR_TYPE_ARRAY << 5 | SUBTYPE_INDEFINITE)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
50 BEGIN_INDEFINITE_MAP = struct.pack(
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
51 r'>B', MAJOR_TYPE_MAP << 5 | SUBTYPE_INDEFINITE)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
52
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
53 ENCODED_LENGTH_1 = struct.Struct(r'>B')
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
54 ENCODED_LENGTH_2 = struct.Struct(r'>BB')
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
55 ENCODED_LENGTH_3 = struct.Struct(r'>BH')
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
56 ENCODED_LENGTH_4 = struct.Struct(r'>BL')
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
57 ENCODED_LENGTH_5 = struct.Struct(r'>BQ')
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
58
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
59 # The break ends an indefinite length item.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
60 BREAK = b'\xff'
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
61 BREAK_INT = 255
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
62
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
63 def encodelength(majortype, length):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
64 """Obtain a value encoding the major type and its length."""
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
65 if length < 24:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
66 return ENCODED_LENGTH_1.pack(majortype << 5 | length)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
67 elif length < 256:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
68 return ENCODED_LENGTH_2.pack(majortype << 5 | 24, length)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
69 elif length < 65536:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
70 return ENCODED_LENGTH_3.pack(majortype << 5 | 25, length)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
71 elif length < 4294967296:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
72 return ENCODED_LENGTH_4.pack(majortype << 5 | 26, length)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
73 else:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
74 return ENCODED_LENGTH_5.pack(majortype << 5 | 27, length)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
75
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
76 def streamencodebytestring(v):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
77 yield encodelength(MAJOR_TYPE_BYTESTRING, len(v))
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
78 yield v
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
79
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
80 def streamencodebytestringfromiter(it):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
81 """Convert an iterator of chunks to an indefinite bytestring.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
82
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
83 Given an input that is iterable and each element in the iterator is
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
84 representable as bytes, emit an indefinite length bytestring.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
85 """
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
86 yield BEGIN_INDEFINITE_BYTESTRING
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
87
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
88 for chunk in it:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
89 yield encodelength(MAJOR_TYPE_BYTESTRING, len(chunk))
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
90 yield chunk
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
91
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
92 yield BREAK
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
93
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
94 def streamencodeindefinitebytestring(source, chunksize=65536):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
95 """Given a large source buffer, emit as an indefinite length bytestring.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
96
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
97 This is a generator of chunks constituting the encoded CBOR data.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
98 """
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
99 yield BEGIN_INDEFINITE_BYTESTRING
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
100
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
101 i = 0
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
102 l = len(source)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
103
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
104 while True:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
105 chunk = source[i:i + chunksize]
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
106 i += len(chunk)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
107
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
108 yield encodelength(MAJOR_TYPE_BYTESTRING, len(chunk))
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
109 yield chunk
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
110
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
111 if i >= l:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
112 break
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
113
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
114 yield BREAK
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
115
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
116 def streamencodeint(v):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
117 if v >= 18446744073709551616 or v < -18446744073709551616:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
118 raise ValueError('big integers not supported')
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
119
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
120 if v >= 0:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
121 yield encodelength(MAJOR_TYPE_UINT, v)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
122 else:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
123 yield encodelength(MAJOR_TYPE_NEGINT, abs(v) - 1)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
124
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
125 def streamencodearray(l):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
126 """Encode a known size iterable to an array."""
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
127
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
128 yield encodelength(MAJOR_TYPE_ARRAY, len(l))
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
129
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
130 for i in l:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
131 for chunk in streamencode(i):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
132 yield chunk
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
133
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
134 def streamencodearrayfromiter(it):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
135 """Encode an iterator of items to an indefinite length array."""
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
136
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
137 yield BEGIN_INDEFINITE_ARRAY
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
138
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
139 for i in it:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
140 for chunk in streamencode(i):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
141 yield chunk
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
142
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
143 yield BREAK
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
144
37942
2ae6a3134362 cborutil: port to Python 3
Augie Fackler <augie@google.com>
parents: 37711
diff changeset
145 def _mixedtypesortkey(v):
2ae6a3134362 cborutil: port to Python 3
Augie Fackler <augie@google.com>
parents: 37711
diff changeset
146 return type(v).__name__, v
2ae6a3134362 cborutil: port to Python 3
Augie Fackler <augie@google.com>
parents: 37711
diff changeset
147
37711
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
148 def streamencodeset(s):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
149 # https://www.iana.org/assignments/cbor-tags/cbor-tags.xhtml defines
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
150 # semantic tag 258 for finite sets.
39438
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
151 yield encodelength(MAJOR_TYPE_SEMANTIC, SEMANTIC_TAG_FINITE_SET)
37711
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
152
37942
2ae6a3134362 cborutil: port to Python 3
Augie Fackler <augie@google.com>
parents: 37711
diff changeset
153 for chunk in streamencodearray(sorted(s, key=_mixedtypesortkey)):
37711
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
154 yield chunk
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
155
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
156 def streamencodemap(d):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
157 """Encode dictionary to a generator.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
158
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
159 Does not supporting indefinite length dictionaries.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
160 """
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
161 yield encodelength(MAJOR_TYPE_MAP, len(d))
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
162
37942
2ae6a3134362 cborutil: port to Python 3
Augie Fackler <augie@google.com>
parents: 37711
diff changeset
163 for key, value in sorted(d.iteritems(),
2ae6a3134362 cborutil: port to Python 3
Augie Fackler <augie@google.com>
parents: 37711
diff changeset
164 key=lambda x: _mixedtypesortkey(x[0])):
37711
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
165 for chunk in streamencode(key):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
166 yield chunk
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
167 for chunk in streamencode(value):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
168 yield chunk
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
169
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
170 def streamencodemapfromiter(it):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
171 """Given an iterable of (key, value), encode to an indefinite length map."""
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
172 yield BEGIN_INDEFINITE_MAP
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
173
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
174 for key, value in it:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
175 for chunk in streamencode(key):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
176 yield chunk
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
177 for chunk in streamencode(value):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
178 yield chunk
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
179
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
180 yield BREAK
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
181
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
182 def streamencodebool(b):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
183 # major type 7, simple value 20 and 21.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
184 yield b'\xf5' if b else b'\xf4'
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
185
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
186 def streamencodenone(v):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
187 # major type 7, simple value 22.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
188 yield b'\xf6'
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
189
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
190 STREAM_ENCODERS = {
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
191 bytes: streamencodebytestring,
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
192 int: streamencodeint,
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
193 list: streamencodearray,
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
194 tuple: streamencodearray,
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
195 dict: streamencodemap,
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
196 set: streamencodeset,
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
197 bool: streamencodebool,
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
198 type(None): streamencodenone,
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
199 }
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
200
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
201 def streamencode(v):
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
202 """Encode a value in a streaming manner.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
203
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
204 Given an input object, encode it to CBOR recursively.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
205
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
206 Returns a generator of CBOR encoded bytes. There is no guarantee
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
207 that each emitted chunk fully decodes to a value or sub-value.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
208
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
209 Encoding is deterministic - unordered collections are sorted.
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
210 """
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
211 fn = STREAM_ENCODERS.get(v.__class__)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
212
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
213 if not fn:
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
214 raise ValueError('do not know how to encode %s' % type(v))
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
215
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
216 return fn(v)
65a23cc8e75b cborutil: implement support for streaming encoding, bytestring decoding
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff changeset
217
39438
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
218 class CBORDecodeError(Exception):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
219 """Represents an error decoding CBOR."""
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
220
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
221 if sys.version_info.major >= 3:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
222 def _elementtointeger(b, i):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
223 return b[i]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
224 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
225 def _elementtointeger(b, i):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
226 return ord(b[i])
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
227
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
228 STRUCT_BIG_UBYTE = struct.Struct(r'>B')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
229 STRUCT_BIG_USHORT = struct.Struct('>H')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
230 STRUCT_BIG_ULONG = struct.Struct('>L')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
231 STRUCT_BIG_ULONGLONG = struct.Struct('>Q')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
232
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
233 SPECIAL_NONE = 0
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
234 SPECIAL_START_INDEFINITE_BYTESTRING = 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
235 SPECIAL_START_ARRAY = 2
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
236 SPECIAL_START_MAP = 3
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
237 SPECIAL_START_SET = 4
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
238 SPECIAL_INDEFINITE_BREAK = 5
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
239
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
240 def decodeitem(b, offset=0):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
241 """Decode a new CBOR value from a buffer at offset.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
242
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
243 This function attempts to decode up to one complete CBOR value
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
244 from ``b`` starting at offset ``offset``.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
245
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
246 The beginning of a collection (such as an array, map, set, or
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
247 indefinite length bytestring) counts as a single value. For these
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
248 special cases, a state flag will indicate that a special value was seen.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
249
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
250 When called, the function either returns a decoded value or gives
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
251 a hint as to how many more bytes are needed to do so. By calling
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
252 the function repeatedly given a stream of bytes, the caller can
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
253 build up the original values.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
254
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
255 Returns a tuple with the following elements:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
256
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
257 * Bool indicating whether a complete value was decoded.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
258 * A decoded value if first value is True otherwise None
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
259 * Integer number of bytes. If positive, the number of bytes
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
260 read. If negative, the number of bytes we need to read to
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
261 decode this value or the next chunk in this value.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
262 * One of the ``SPECIAL_*`` constants indicating special treatment
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
263 for this value. ``SPECIAL_NONE`` means this is a fully decoded
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
264 simple value (such as an integer or bool).
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
265 """
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
266
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
267 initial = _elementtointeger(b, offset)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
268 offset += 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
269
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
270 majortype = initial >> 5
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
271 subtype = initial & SUBTYPE_MASK
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
272
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
273 if majortype == MAJOR_TYPE_UINT:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
274 complete, value, readcount = decodeuint(subtype, b, offset)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
275
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
276 if complete:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
277 return True, value, readcount + 1, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
278 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
279 return False, None, readcount, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
280
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
281 elif majortype == MAJOR_TYPE_NEGINT:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
282 # Negative integers are the same as UINT except inverted minus 1.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
283 complete, value, readcount = decodeuint(subtype, b, offset)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
284
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
285 if complete:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
286 return True, -value - 1, readcount + 1, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
287 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
288 return False, None, readcount, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
289
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
290 elif majortype == MAJOR_TYPE_BYTESTRING:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
291 # Beginning of bytestrings are treated as uints in order to
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
292 # decode their length, which may be indefinite.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
293 complete, size, readcount = decodeuint(subtype, b, offset,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
294 allowindefinite=True)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
295
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
296 # We don't know the size of the bytestring. It must be a definitive
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
297 # length since the indefinite subtype would be encoded in the initial
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
298 # byte.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
299 if not complete:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
300 return False, None, readcount, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
301
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
302 # We know the length of the bytestring.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
303 if size is not None:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
304 # And the data is available in the buffer.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
305 if offset + readcount + size <= len(b):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
306 value = b[offset + readcount:offset + readcount + size]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
307 return True, value, readcount + size + 1, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
308
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
309 # And we need more data in order to return the bytestring.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
310 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
311 wanted = len(b) - offset - readcount - size
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
312 return False, None, wanted, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
313
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
314 # It is an indefinite length bytestring.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
315 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
316 return True, None, 1, SPECIAL_START_INDEFINITE_BYTESTRING
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
317
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
318 elif majortype == MAJOR_TYPE_STRING:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
319 raise CBORDecodeError('string major type not supported')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
320
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
321 elif majortype == MAJOR_TYPE_ARRAY:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
322 # Beginning of arrays are treated as uints in order to decode their
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
323 # length. We don't allow indefinite length arrays.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
324 complete, size, readcount = decodeuint(subtype, b, offset)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
325
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
326 if complete:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
327 return True, size, readcount + 1, SPECIAL_START_ARRAY
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
328 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
329 return False, None, readcount, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
330
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
331 elif majortype == MAJOR_TYPE_MAP:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
332 # Beginning of maps are treated as uints in order to decode their
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
333 # number of elements. We don't allow indefinite length arrays.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
334 complete, size, readcount = decodeuint(subtype, b, offset)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
335
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
336 if complete:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
337 return True, size, readcount + 1, SPECIAL_START_MAP
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
338 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
339 return False, None, readcount, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
340
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
341 elif majortype == MAJOR_TYPE_SEMANTIC:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
342 # Semantic tag value is read the same as a uint.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
343 complete, tagvalue, readcount = decodeuint(subtype, b, offset)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
344
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
345 if not complete:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
346 return False, None, readcount, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
347
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
348 # This behavior here is a little wonky. The main type being "decorated"
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
349 # by this semantic tag follows. A more robust parser would probably emit
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
350 # a special flag indicating this as a semantic tag and let the caller
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
351 # deal with the types that follow. But since we don't support many
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
352 # semantic tags, it is easier to deal with the special cases here and
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
353 # hide complexity from the caller. If we add support for more semantic
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
354 # tags, we should probably move semantic tag handling into the caller.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
355 if tagvalue == SEMANTIC_TAG_FINITE_SET:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
356 if offset + readcount >= len(b):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
357 return False, None, -1, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
358
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
359 complete, size, readcount2, special = decodeitem(b,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
360 offset + readcount)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
361
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
362 if not complete:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
363 return False, None, readcount2, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
364
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
365 if special != SPECIAL_START_ARRAY:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
366 raise CBORDecodeError('expected array after finite set '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
367 'semantic tag')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
368
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
369 return True, size, readcount + readcount2 + 1, SPECIAL_START_SET
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
370
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
371 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
372 raise CBORDecodeError('semantic tag %d not allowed' % tagvalue)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
373
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
374 elif majortype == MAJOR_TYPE_SPECIAL:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
375 # Only specific values for the information field are allowed.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
376 if subtype == SUBTYPE_FALSE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
377 return True, False, 1, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
378 elif subtype == SUBTYPE_TRUE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
379 return True, True, 1, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
380 elif subtype == SUBTYPE_NULL:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
381 return True, None, 1, SPECIAL_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
382 elif subtype == SUBTYPE_INDEFINITE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
383 return True, None, 1, SPECIAL_INDEFINITE_BREAK
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
384 # If value is 24, subtype is in next byte.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
385 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
386 raise CBORDecodeError('special type %d not allowed' % subtype)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
387 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
388 assert False
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
389
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
390 def decodeuint(subtype, b, offset=0, allowindefinite=False):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
391 """Decode an unsigned integer.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
392
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
393 ``subtype`` is the lower 5 bits from the initial byte CBOR item
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
394 "header." ``b`` is a buffer containing bytes. ``offset`` points to
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
395 the index of the first byte after the byte that ``subtype`` was
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
396 derived from.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
397
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
398 ``allowindefinite`` allows the special indefinite length value
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
399 indicator.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
400
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
401 Returns a 3-tuple of (successful, value, count).
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
402
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
403 The first element is a bool indicating if decoding completed. The 2nd
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
404 is the decoded integer value or None if not fully decoded or the subtype
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
405 is 31 and ``allowindefinite`` is True. The 3rd value is the count of bytes.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
406 If positive, it is the number of additional bytes decoded. If negative,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
407 it is the number of additional bytes needed to decode this value.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
408 """
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
409
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
410 # Small values are inline.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
411 if subtype < 24:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
412 return True, subtype, 0
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
413 # Indefinite length specifier.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
414 elif subtype == 31:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
415 if allowindefinite:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
416 return True, None, 0
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
417 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
418 raise CBORDecodeError('indefinite length uint not allowed here')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
419 elif subtype >= 28:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
420 raise CBORDecodeError('unsupported subtype on integer type: %d' %
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
421 subtype)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
422
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
423 if subtype == 24:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
424 s = STRUCT_BIG_UBYTE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
425 elif subtype == 25:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
426 s = STRUCT_BIG_USHORT
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
427 elif subtype == 26:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
428 s = STRUCT_BIG_ULONG
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
429 elif subtype == 27:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
430 s = STRUCT_BIG_ULONGLONG
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
431 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
432 raise CBORDecodeError('bounds condition checking violation')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
433
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
434 if len(b) - offset >= s.size:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
435 return True, s.unpack_from(b, offset)[0], s.size
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
436 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
437 return False, None, len(b) - offset - s.size
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
438
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
439 class bytestringchunk(bytes):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
440 """Represents a chunk/segment in an indefinite length bytestring.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
441
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
442 This behaves like a ``bytes`` but in addition has the ``isfirst``
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
443 and ``islast`` attributes indicating whether this chunk is the first
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
444 or last in an indefinite length bytestring.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
445 """
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
446
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
447 def __new__(cls, v, first=False, last=False):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
448 self = bytes.__new__(cls, v)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
449 self.isfirst = first
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
450 self.islast = last
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
451
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
452 return self
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
453
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
454 class sansiodecoder(object):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
455 """A CBOR decoder that doesn't perform its own I/O.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
456
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
457 To use, construct an instance and feed it segments containing
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
458 CBOR-encoded bytes via ``decode()``. The return value from ``decode()``
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
459 indicates whether a fully-decoded value is available, how many bytes
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
460 were consumed, and offers a hint as to how many bytes should be fed
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
461 in next time to decode the next value.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
462
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
463 The decoder assumes it will decode N discrete CBOR values, not just
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
464 a single value. i.e. if the bytestream contains uints packed one after
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
465 the other, the decoder will decode them all, rather than just the initial
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
466 one.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
467
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
468 When ``decode()`` indicates a value is available, call ``getavailable()``
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
469 to return all fully decoded values.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
470
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
471 ``decode()`` can partially decode input. It is up to the caller to keep
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
472 track of what data was consumed and to pass unconsumed data in on the
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
473 next invocation.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
474
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
475 The decoder decodes atomically at the *item* level. See ``decodeitem()``.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
476 If an *item* cannot be fully decoded, the decoder won't record it as
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
477 partially consumed. Instead, the caller will be instructed to pass in
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
478 the initial bytes of this item on the next invocation. This does result
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
479 in some redundant parsing. But the overhead should be minimal.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
480
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
481 This decoder only supports a subset of CBOR as required by Mercurial.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
482 It lacks support for:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
483
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
484 * Indefinite length arrays
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
485 * Indefinite length maps
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
486 * Use of indefinite length bytestrings as keys or values within
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
487 arrays, maps, or sets.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
488 * Nested arrays, maps, or sets within sets
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
489 * Any semantic tag that isn't a mathematical finite set
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
490 * Floating point numbers
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
491 * Undefined special value
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
492
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
493 CBOR types are decoded to Python types as follows:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
494
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
495 uint -> int
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
496 negint -> int
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
497 bytestring -> bytes
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
498 map -> dict
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
499 array -> list
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
500 True -> bool
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
501 False -> bool
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
502 null -> None
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
503 indefinite length bytestring chunk -> [bytestringchunk]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
504
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
505 The only non-obvious mapping here is an indefinite length bytestring
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
506 to the ``bytestringchunk`` type. This is to facilitate streaming
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
507 indefinite length bytestrings out of the decoder and to differentiate
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
508 a regular bytestring from an indefinite length bytestring.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
509 """
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
510
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
511 _STATE_NONE = 0
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
512 _STATE_WANT_MAP_KEY = 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
513 _STATE_WANT_MAP_VALUE = 2
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
514 _STATE_WANT_ARRAY_VALUE = 3
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
515 _STATE_WANT_SET_VALUE = 4
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
516 _STATE_WANT_BYTESTRING_CHUNK_FIRST = 5
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
517 _STATE_WANT_BYTESTRING_CHUNK_SUBSEQUENT = 6
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
518
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
519 def __init__(self):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
520 # TODO add support for limiting size of bytestrings
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
521 # TODO add support for limiting number of keys / values in collections
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
522 # TODO add support for limiting size of buffered partial values
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
523
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
524 self.decodedbytecount = 0
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
525
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
526 self._state = self._STATE_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
527
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
528 # Stack of active nested collections. Each entry is a dict describing
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
529 # the collection.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
530 self._collectionstack = []
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
531
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
532 # Fully decoded key to use for the current map.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
533 self._currentmapkey = None
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
534
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
535 # Fully decoded values available for retrieval.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
536 self._decodedvalues = []
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
537
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
538 @property
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
539 def inprogress(self):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
540 """Whether the decoder has partially decoded a value."""
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
541 return self._state != self._STATE_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
542
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
543 def decode(self, b, offset=0):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
544 """Attempt to decode bytes from an input buffer.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
545
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
546 ``b`` is a collection of bytes and ``offset`` is the byte
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
547 offset within that buffer from which to begin reading data.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
548
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
549 ``b`` must support ``len()`` and accessing bytes slices via
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
550 ``__slice__``. Typically ``bytes`` instances are used.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
551
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
552 Returns a tuple with the following fields:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
553
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
554 * Bool indicating whether values are available for retrieval.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
555 * Integer indicating the number of bytes that were fully consumed,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
556 starting from ``offset``.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
557 * Integer indicating the number of bytes that are desired for the
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
558 next call in order to decode an item.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
559 """
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
560 if not b:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
561 return bool(self._decodedvalues), 0, 0
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
562
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
563 initialoffset = offset
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
564
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
565 # We could easily split the body of this loop into a function. But
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
566 # Python performance is sensitive to function calls and collections
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
567 # are composed of many items. So leaving as a while loop could help
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
568 # with performance. One thing that may not help is the use of
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
569 # if..elif versus a lookup/dispatch table. There may be value
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
570 # in switching that.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
571 while offset < len(b):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
572 # Attempt to decode an item. This could be a whole value or a
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
573 # special value indicating an event, such as start or end of a
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
574 # collection or indefinite length type.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
575 complete, value, readcount, special = decodeitem(b, offset)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
576
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
577 if readcount > 0:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
578 self.decodedbytecount += readcount
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
579
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
580 if not complete:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
581 assert readcount < 0
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
582 return (
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
583 bool(self._decodedvalues),
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
584 offset - initialoffset,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
585 -readcount,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
586 )
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
587
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
588 offset += readcount
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
589
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
590 # No nested state. We either have a full value or beginning of a
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
591 # complex value to deal with.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
592 if self._state == self._STATE_NONE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
593 # A normal value.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
594 if special == SPECIAL_NONE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
595 self._decodedvalues.append(value)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
596
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
597 elif special == SPECIAL_START_ARRAY:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
598 self._collectionstack.append({
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
599 'remaining': value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
600 'v': [],
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
601 })
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
602 self._state = self._STATE_WANT_ARRAY_VALUE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
603
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
604 elif special == SPECIAL_START_MAP:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
605 self._collectionstack.append({
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
606 'remaining': value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
607 'v': {},
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
608 })
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
609 self._state = self._STATE_WANT_MAP_KEY
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
610
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
611 elif special == SPECIAL_START_SET:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
612 self._collectionstack.append({
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
613 'remaining': value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
614 'v': set(),
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
615 })
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
616 self._state = self._STATE_WANT_SET_VALUE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
617
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
618 elif special == SPECIAL_START_INDEFINITE_BYTESTRING:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
619 self._state = self._STATE_WANT_BYTESTRING_CHUNK_FIRST
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
620
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
621 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
622 raise CBORDecodeError('unhandled special state: %d' %
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
623 special)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
624
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
625 # This value becomes an element of the current array.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
626 elif self._state == self._STATE_WANT_ARRAY_VALUE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
627 # Simple values get appended.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
628 if special == SPECIAL_NONE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
629 c = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
630 c['v'].append(value)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
631 c['remaining'] -= 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
632
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
633 # self._state doesn't need changed.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
634
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
635 # An array nested within an array.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
636 elif special == SPECIAL_START_ARRAY:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
637 lastc = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
638 newvalue = []
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
639
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
640 lastc['v'].append(newvalue)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
641 lastc['remaining'] -= 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
642
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
643 self._collectionstack.append({
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
644 'remaining': value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
645 'v': newvalue,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
646 })
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
647
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
648 # self._state doesn't need changed.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
649
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
650 # A map nested within an array.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
651 elif special == SPECIAL_START_MAP:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
652 lastc = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
653 newvalue = {}
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
654
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
655 lastc['v'].append(newvalue)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
656 lastc['remaining'] -= 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
657
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
658 self._collectionstack.append({
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
659 'remaining': value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
660 'v': newvalue
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
661 })
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
662
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
663 self._state = self._STATE_WANT_MAP_KEY
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
664
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
665 elif special == SPECIAL_START_SET:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
666 lastc = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
667 newvalue = set()
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
668
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
669 lastc['v'].append(newvalue)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
670 lastc['remaining'] -= 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
671
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
672 self._collectionstack.append({
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
673 'remaining': value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
674 'v': newvalue,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
675 })
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
676
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
677 self._state = self._STATE_WANT_SET_VALUE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
678
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
679 elif special == SPECIAL_START_INDEFINITE_BYTESTRING:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
680 raise CBORDecodeError('indefinite length bytestrings '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
681 'not allowed as array values')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
682
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
683 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
684 raise CBORDecodeError('unhandled special item when '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
685 'expecting array value: %d' % special)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
686
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
687 # This value becomes the key of the current map instance.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
688 elif self._state == self._STATE_WANT_MAP_KEY:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
689 if special == SPECIAL_NONE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
690 self._currentmapkey = value
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
691 self._state = self._STATE_WANT_MAP_VALUE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
692
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
693 elif special == SPECIAL_START_INDEFINITE_BYTESTRING:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
694 raise CBORDecodeError('indefinite length bytestrings '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
695 'not allowed as map keys')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
696
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
697 elif special in (SPECIAL_START_ARRAY, SPECIAL_START_MAP,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
698 SPECIAL_START_SET):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
699 raise CBORDecodeError('collections not supported as map '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
700 'keys')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
701
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
702 # We do not allow special values to be used as map keys.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
703 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
704 raise CBORDecodeError('unhandled special item when '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
705 'expecting map key: %d' % special)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
706
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
707 # This value becomes the value of the current map key.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
708 elif self._state == self._STATE_WANT_MAP_VALUE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
709 # Simple values simply get inserted into the map.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
710 if special == SPECIAL_NONE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
711 lastc = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
712 lastc['v'][self._currentmapkey] = value
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
713 lastc['remaining'] -= 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
714
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
715 self._state = self._STATE_WANT_MAP_KEY
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
716
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
717 # A new array is used as the map value.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
718 elif special == SPECIAL_START_ARRAY:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
719 lastc = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
720 newvalue = []
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
721
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
722 lastc['v'][self._currentmapkey] = newvalue
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
723 lastc['remaining'] -= 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
724
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
725 self._collectionstack.append({
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
726 'remaining': value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
727 'v': newvalue,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
728 })
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
729
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
730 self._state = self._STATE_WANT_ARRAY_VALUE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
731
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
732 # A new map is used as the map value.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
733 elif special == SPECIAL_START_MAP:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
734 lastc = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
735 newvalue = {}
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
736
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
737 lastc['v'][self._currentmapkey] = newvalue
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
738 lastc['remaining'] -= 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
739
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
740 self._collectionstack.append({
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
741 'remaining': value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
742 'v': newvalue,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
743 })
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
744
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
745 self._state = self._STATE_WANT_MAP_KEY
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
746
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
747 # A new set is used as the map value.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
748 elif special == SPECIAL_START_SET:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
749 lastc = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
750 newvalue = set()
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
751
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
752 lastc['v'][self._currentmapkey] = newvalue
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
753 lastc['remaining'] -= 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
754
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
755 self._collectionstack.append({
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
756 'remaining': value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
757 'v': newvalue,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
758 })
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
759
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
760 self._state = self._STATE_WANT_SET_VALUE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
761
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
762 elif special == SPECIAL_START_INDEFINITE_BYTESTRING:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
763 raise CBORDecodeError('indefinite length bytestrings not '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
764 'allowed as map values')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
765
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
766 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
767 raise CBORDecodeError('unhandled special item when '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
768 'expecting map value: %d' % special)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
769
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
770 self._currentmapkey = None
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
771
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
772 # This value is added to the current set.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
773 elif self._state == self._STATE_WANT_SET_VALUE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
774 if special == SPECIAL_NONE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
775 lastc = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
776 lastc['v'].add(value)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
777 lastc['remaining'] -= 1
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
778
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
779 elif special == SPECIAL_START_INDEFINITE_BYTESTRING:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
780 raise CBORDecodeError('indefinite length bytestrings not '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
781 'allowed as set values')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
782
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
783 elif special in (SPECIAL_START_ARRAY,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
784 SPECIAL_START_MAP,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
785 SPECIAL_START_SET):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
786 raise CBORDecodeError('collections not allowed as set '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
787 'values')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
788
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
789 # We don't allow non-trivial types to exist as set values.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
790 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
791 raise CBORDecodeError('unhandled special item when '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
792 'expecting set value: %d' % special)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
793
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
794 # This value represents the first chunk in an indefinite length
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
795 # bytestring.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
796 elif self._state == self._STATE_WANT_BYTESTRING_CHUNK_FIRST:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
797 # We received a full chunk.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
798 if special == SPECIAL_NONE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
799 self._decodedvalues.append(bytestringchunk(value,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
800 first=True))
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
801
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
802 self._state = self._STATE_WANT_BYTESTRING_CHUNK_SUBSEQUENT
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
803
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
804 # The end of stream marker. This means it is an empty
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
805 # indefinite length bytestring.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
806 elif special == SPECIAL_INDEFINITE_BREAK:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
807 # We /could/ convert this to a b''. But we want to preserve
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
808 # the nature of the underlying data so consumers expecting
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
809 # an indefinite length bytestring get one.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
810 self._decodedvalues.append(bytestringchunk(b'',
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
811 first=True,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
812 last=True))
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
813
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
814 # Since indefinite length bytestrings can't be used in
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
815 # collections, we must be at the root level.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
816 assert not self._collectionstack
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
817 self._state = self._STATE_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
818
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
819 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
820 raise CBORDecodeError('unexpected special value when '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
821 'expecting bytestring chunk: %d' %
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
822 special)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
823
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
824 # This value represents the non-initial chunk in an indefinite
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
825 # length bytestring.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
826 elif self._state == self._STATE_WANT_BYTESTRING_CHUNK_SUBSEQUENT:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
827 # We received a full chunk.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
828 if special == SPECIAL_NONE:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
829 self._decodedvalues.append(bytestringchunk(value))
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
830
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
831 # The end of stream marker.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
832 elif special == SPECIAL_INDEFINITE_BREAK:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
833 self._decodedvalues.append(bytestringchunk(b'', last=True))
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
834
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
835 # Since indefinite length bytestrings can't be used in
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
836 # collections, we must be at the root level.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
837 assert not self._collectionstack
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
838 self._state = self._STATE_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
839
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
840 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
841 raise CBORDecodeError('unexpected special value when '
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
842 'expecting bytestring chunk: %d' %
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
843 special)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
844
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
845 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
846 raise CBORDecodeError('unhandled decoder state: %d' %
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
847 self._state)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
848
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
849 # We could have just added the final value in a collection. End
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
850 # all complete collections at the top of the stack.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
851 while True:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
852 # Bail if we're not waiting on a new collection item.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
853 if self._state not in (self._STATE_WANT_ARRAY_VALUE,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
854 self._STATE_WANT_MAP_KEY,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
855 self._STATE_WANT_SET_VALUE):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
856 break
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
857
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
858 # Or we are expecting more items for this collection.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
859 lastc = self._collectionstack[-1]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
860
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
861 if lastc['remaining']:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
862 break
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
863
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
864 # The collection at the top of the stack is complete.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
865
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
866 # Discard it, as it isn't needed for future items.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
867 self._collectionstack.pop()
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
868
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
869 # If this is a nested collection, we don't emit it, since it
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
870 # will be emitted by its parent collection. But we do need to
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
871 # update state to reflect what the new top-most collection
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
872 # on the stack is.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
873 if self._collectionstack:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
874 self._state = {
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
875 list: self._STATE_WANT_ARRAY_VALUE,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
876 dict: self._STATE_WANT_MAP_KEY,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
877 set: self._STATE_WANT_SET_VALUE,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
878 }[type(self._collectionstack[-1]['v'])]
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
879
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
880 # If this is the root collection, emit it.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
881 else:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
882 self._decodedvalues.append(lastc['v'])
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
883 self._state = self._STATE_NONE
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
884
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
885 return (
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
886 bool(self._decodedvalues),
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
887 offset - initialoffset,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
888 0,
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
889 )
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
890
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
891 def getavailable(self):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
892 """Returns an iterator over fully decoded values.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
893
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
894 Once values are retrieved, they won't be available on the next call.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
895 """
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
896
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
897 l = list(self._decodedvalues)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
898 self._decodedvalues = []
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
899 return l
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
900
39440
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
901 class bufferingdecoder(object):
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
902 """A CBOR decoder that buffers undecoded input.
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
903
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
904 This is a glorified wrapper around ``sansiodecoder`` that adds a buffering
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
905 layer. All input that isn't consumed by ``sansiodecoder`` will be buffered
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
906 and concatenated with any new input that arrives later.
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
907
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
908 TODO consider adding limits as to the maximum amount of data that can
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
909 be buffered.
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
910 """
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
911 def __init__(self):
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
912 self._decoder = sansiodecoder()
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
913 self._leftover = None
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
914
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
915 def decode(self, b):
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
916 """Attempt to decode bytes to CBOR values.
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
917
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
918 Returns a tuple with the following fields:
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
919
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
920 * Bool indicating whether new values are available for retrieval.
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
921 * Integer number of bytes decoded from the new input.
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
922 * Integer number of bytes wanted to decode the next value.
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
923 """
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
924
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
925 if self._leftover:
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
926 oldlen = len(self._leftover)
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
927 b = self._leftover + b
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
928 self._leftover = None
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
929 else:
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
930 b = b
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
931 oldlen = 0
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
932
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
933 available, readcount, wanted = self._decoder.decode(b)
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
934
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
935 if readcount < len(b):
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
936 self._leftover = b[readcount:]
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
937
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
938 return available, readcount - oldlen, wanted
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
939
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
940 def getavailable(self):
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
941 return self._decoder.getavailable()
babad5ebaf0a cborutil: add a buffering decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 39439
diff changeset
942
39438
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
943 def decodeall(b):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
944 """Decode all CBOR items present in an iterable of bytes.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
945
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
946 In addition to regular decode errors, raises CBORDecodeError if the
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
947 entirety of the passed buffer does not fully decode to complete CBOR
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
948 values. This includes failure to decode any value, incomplete collection
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
949 types, incomplete indefinite length items, and extra data at the end of
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
950 the buffer.
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
951 """
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
952 if not b:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
953 return []
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
954
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
955 decoder = sansiodecoder()
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
956
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
957 havevalues, readcount, wantbytes = decoder.decode(b)
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
958
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
959 if readcount != len(b):
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
960 raise CBORDecodeError('input data not fully consumed')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
961
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
962 if decoder.inprogress:
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
963 raise CBORDecodeError('input data not complete')
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
964
aeb551a3bb8a cborutil: implement sans I/O decoder
Gregory Szorc <gregory.szorc@gmail.com>
parents: 37942
diff changeset
965 return decoder.getavailable()