Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/google/protobuf/internal/wire_format.py: 53%

1# Protocol Buffers - Google's data interchange format 

2# Copyright 2008 Google Inc. All rights reserved. 

3# 

4# Use of this source code is governed by a BSD-style 

5# license that can be found in the LICENSE file or at 

6# https://developers.google.com/open-source/licenses/bsd 

7 

8"""Constants and static functions to support protocol buffer wire format.""" 

9 

10__author__ = 'robinson@google.com (Will Robinson)' 

11 

12import struct 

13from google.protobuf import descriptor 

14from google.protobuf import message 

15 

16 

17TAG_TYPE_BITS = 3 # Number of bits used to hold type info in a proto tag. 

18TAG_TYPE_MASK = (1 << TAG_TYPE_BITS) - 1 # 0x7 

19 

20# These numbers identify the wire type of a protocol buffer value. 

21# We use the least-significant TAG_TYPE_BITS bits of the varint-encoded 

22# tag-and-type to store one of these WIRETYPE_* constants. 

23# These values must match WireType enum in //google/protobuf/wire_format.h. 

24WIRETYPE_VARINT = 0 

25WIRETYPE_FIXED64 = 1 

26WIRETYPE_LENGTH_DELIMITED = 2 

27WIRETYPE_START_GROUP = 3 

28WIRETYPE_END_GROUP = 4 

29WIRETYPE_FIXED32 = 5 

30_WIRETYPE_MAX = 5 

31 

32 

33# Bounds for various integer types. 

34INT32_MAX = int((1 << 31) - 1) 

35INT32_MIN = int(-(1 << 31)) 

36UINT32_MAX = (1 << 32) - 1 

37 

38INT64_MAX = (1 << 63) - 1 

39INT64_MIN = -(1 << 63) 

40UINT64_MAX = (1 << 64) - 1 

41 

42# "struct" format strings that will encode/decode the specified formats. 

43FORMAT_UINT32_LITTLE_ENDIAN = '<I' 

44FORMAT_UINT64_LITTLE_ENDIAN = '<Q' 

45FORMAT_FLOAT_LITTLE_ENDIAN = '<f' 

46FORMAT_DOUBLE_LITTLE_ENDIAN = '<d' 

47 

48 

49# We'll have to provide alternate implementations of AppendLittleEndian*() on 

50# any architectures where these checks fail. 

51if struct.calcsize(FORMAT_UINT32_LITTLE_ENDIAN) != 4: 

52 raise AssertionError('Format "I" is not a 32-bit number.') 

53if struct.calcsize(FORMAT_UINT64_LITTLE_ENDIAN) != 8: 

54 raise AssertionError('Format "Q" is not a 64-bit number.') 

55 

56 

57def PackTag(field_number, wire_type): 

58 """Returns an unsigned 32-bit integer that encodes the field number and 

59 wire type information in standard protocol message wire format. 

60 

61 Args: 

62 field_number: Expected to be an integer in the range [1, 1 << 29) 

63 wire_type: One of the WIRETYPE_* constants. 

64 """ 

65 if not 0 <= wire_type <= _WIRETYPE_MAX: 

66 raise message.EncodeError('Unknown wire type: %d' % wire_type) 

67 return (field_number << TAG_TYPE_BITS) | wire_type 

68 

69 

70def UnpackTag(tag): 

71 """The inverse of PackTag(). Given an unsigned 32-bit number, 

72 returns a (field_number, wire_type) tuple. 

73 """ 

74 return (tag >> TAG_TYPE_BITS), (tag & TAG_TYPE_MASK) 

75 

76 

77def ZigZagEncode(value): 

78 """ZigZag Transform: Encodes signed integers so that they can be 

79 effectively used with varint encoding. See wire_format.h for 

80 more details. 

81 """ 

82 if value >= 0: 

83 return value << 1 

84 return (value << 1) ^ (~0) 

85 

86 

87def ZigZagDecode(value): 

88 """Inverse of ZigZagEncode().""" 

89 if not value & 0x1: 

90 return value >> 1 

91 return (value >> 1) ^ (~0) 

92 

93 

94 

95# The *ByteSize() functions below return the number of bytes required to 

96# serialize "field number + type" information and then serialize the value. 

97 

98 

99def Int32ByteSize(field_number, int32): 

100 return Int64ByteSize(field_number, int32) 

101 

102 

103def Int32ByteSizeNoTag(int32): 

104 return _VarUInt64ByteSizeNoTag(0xffffffffffffffff & int32) 

105 

106 

107def Int64ByteSize(field_number, int64): 

108 # Have to convert to uint before calling UInt64ByteSize(). 

109 return UInt64ByteSize(field_number, 0xffffffffffffffff & int64) 

110 

111 

112def UInt32ByteSize(field_number, uint32): 

113 return UInt64ByteSize(field_number, uint32) 

114 

115 

116def UInt64ByteSize(field_number, uint64): 

117 return TagByteSize(field_number) + _VarUInt64ByteSizeNoTag(uint64) 

118 

119 

120def SInt32ByteSize(field_number, int32): 

121 return UInt32ByteSize(field_number, ZigZagEncode(int32)) 

122 

123 

124def SInt64ByteSize(field_number, int64): 

125 return UInt64ByteSize(field_number, ZigZagEncode(int64)) 

126 

127 

128def Fixed32ByteSize(field_number, fixed32): 

129 return TagByteSize(field_number) + 4 

130 

131 

132def Fixed64ByteSize(field_number, fixed64): 

133 return TagByteSize(field_number) + 8 

134 

135 

136def SFixed32ByteSize(field_number, sfixed32): 

137 return TagByteSize(field_number) + 4 

138 

139 

140def SFixed64ByteSize(field_number, sfixed64): 

141 return TagByteSize(field_number) + 8 

142 

143 

144def FloatByteSize(field_number, flt): 

145 return TagByteSize(field_number) + 4 

146 

147 

148def DoubleByteSize(field_number, double): 

149 return TagByteSize(field_number) + 8 

150 

151 

152def BoolByteSize(field_number, b): 

153 return TagByteSize(field_number) + 1 

154 

155 

156def EnumByteSize(field_number, enum): 

157 return UInt32ByteSize(field_number, enum) 

158 

159 

160def StringByteSize(field_number, string): 

161 return BytesByteSize(field_number, string.encode('utf-8')) 

162 

163 

164def BytesByteSize(field_number, b): 

165 return (TagByteSize(field_number) 

166 + _VarUInt64ByteSizeNoTag(len(b)) 

167 + len(b)) 

168 

169 

170def GroupByteSize(field_number, message): 

171 return (2 * TagByteSize(field_number) # START and END group. 

172 + message.ByteSize()) 

173 

174 

175def MessageByteSize(field_number, message): 

176 return (TagByteSize(field_number) 

177 + _VarUInt64ByteSizeNoTag(message.ByteSize()) 

178 + message.ByteSize()) 

179 

180 

181def MessageSetItemByteSize(field_number, msg): 

182 # First compute the sizes of the tags. 

183 # There are 2 tags for the beginning and ending of the repeated group, that 

184 # is field number 1, one with field number 2 (type_id) and one with field 

185 # number 3 (message). 

186 total_size = (2 * TagByteSize(1) + TagByteSize(2) + TagByteSize(3)) 

187 

188 # Add the number of bytes for type_id. 

189 total_size += _VarUInt64ByteSizeNoTag(field_number) 

190 

191 message_size = msg.ByteSize() 

192 

193 # The number of bytes for encoding the length of the message. 

194 total_size += _VarUInt64ByteSizeNoTag(message_size) 

195 

196 # The size of the message. 

197 total_size += message_size 

198 return total_size 

199 

200 

201def TagByteSize(field_number): 

202 """Returns the bytes required to serialize a tag with this field number.""" 

203 # Just pass in type 0, since the type won't affect the tag+type size. 

204 return _VarUInt64ByteSizeNoTag(PackTag(field_number, 0)) 

205 

206 

207# Private helper function for the *ByteSize() functions above. 

208 

209def _VarUInt64ByteSizeNoTag(uint64): 

210 """Returns the number of bytes required to serialize a single varint 

211 using boundary value comparisons. (unrolled loop optimization -WPierce) 

212 uint64 must be unsigned. 

213 """ 

214 if uint64 <= 0x7f: return 1 

215 if uint64 <= 0x3fff: return 2 

216 if uint64 <= 0x1fffff: return 3 

217 if uint64 <= 0xfffffff: return 4 

218 if uint64 <= 0x7ffffffff: return 5 

219 if uint64 <= 0x3ffffffffff: return 6 

220 if uint64 <= 0x1ffffffffffff: return 7 

221 if uint64 <= 0xffffffffffffff: return 8 

222 if uint64 <= 0x7fffffffffffffff: return 9 

223 if uint64 > UINT64_MAX: 

224 raise message.EncodeError('Value out of range: %d' % uint64) 

225 return 10 

226 

227 

228NON_PACKABLE_TYPES = ( 

229 descriptor.FieldDescriptor.TYPE_STRING, 

230 descriptor.FieldDescriptor.TYPE_GROUP, 

231 descriptor.FieldDescriptor.TYPE_MESSAGE, 

232 descriptor.FieldDescriptor.TYPE_BYTES 

233) 

234 

235 

236def IsTypePackable(field_type): 

237 """Return true iff packable = true is valid for fields of this type. 

238 

239 Args: 

240 field_type: a FieldDescriptor::Type value. 

241 

242 Returns: 

243 True iff fields of this type are packable. 

244 """ 

245 return field_type not in NON_PACKABLE_TYPES