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| 1 # Protocol Buffers - Google's data interchange format |
| 2 # Copyright 2008 Google Inc. All rights reserved. |
| 3 # http://code.google.com/p/protobuf/ |
| 4 # |
| 5 # Redistribution and use in source and binary forms, with or without |
| 6 # modification, are permitted provided that the following conditions are |
| 7 # met: |
| 8 # |
| 9 # * Redistributions of source code must retain the above copyright |
| 10 # notice, this list of conditions and the following disclaimer. |
| 11 # * Redistributions in binary form must reproduce the above |
| 12 # copyright notice, this list of conditions and the following disclaimer |
| 13 # in the documentation and/or other materials provided with the |
| 14 # distribution. |
| 15 # * Neither the name of Google Inc. nor the names of its |
| 16 # contributors may be used to endorse or promote products derived from |
| 17 # this software without specific prior written permission. |
| 18 # |
| 19 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 20 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 21 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 22 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 23 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 24 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 25 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 26 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 27 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 28 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 29 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 30 |
| 31 #PY25 compatible for GAE. |
| 32 # |
| 33 # Copyright 2009 Google Inc. All Rights Reserved. |
| 34 |
| 35 """Code for encoding protocol message primitives. |
| 36 |
| 37 Contains the logic for encoding every logical protocol field type |
| 38 into one of the 5 physical wire types. |
| 39 |
| 40 This code is designed to push the Python interpreter's performance to the |
| 41 limits. |
| 42 |
| 43 The basic idea is that at startup time, for every field (i.e. every |
| 44 FieldDescriptor) we construct two functions: a "sizer" and an "encoder". The |
| 45 sizer takes a value of this field's type and computes its byte size. The |
| 46 encoder takes a writer function and a value. It encodes the value into byte |
| 47 strings and invokes the writer function to write those strings. Typically the |
| 48 writer function is the write() method of a cStringIO. |
| 49 |
| 50 We try to do as much work as possible when constructing the writer and the |
| 51 sizer rather than when calling them. In particular: |
| 52 * We copy any needed global functions to local variables, so that we do not need |
| 53 to do costly global table lookups at runtime. |
| 54 * Similarly, we try to do any attribute lookups at startup time if possible. |
| 55 * Every field's tag is encoded to bytes at startup, since it can't change at |
| 56 runtime. |
| 57 * Whatever component of the field size we can compute at startup, we do. |
| 58 * We *avoid* sharing code if doing so would make the code slower and not sharing |
| 59 does not burden us too much. For example, encoders for repeated fields do |
| 60 not just call the encoders for singular fields in a loop because this would |
| 61 add an extra function call overhead for every loop iteration; instead, we |
| 62 manually inline the single-value encoder into the loop. |
| 63 * If a Python function lacks a return statement, Python actually generates |
| 64 instructions to pop the result of the last statement off the stack, push |
| 65 None onto the stack, and then return that. If we really don't care what |
| 66 value is returned, then we can save two instructions by returning the |
| 67 result of the last statement. It looks funny but it helps. |
| 68 * We assume that type and bounds checking has happened at a higher level. |
| 69 """ |
| 70 |
| 71 __author__ = 'kenton@google.com (Kenton Varda)' |
| 72 |
| 73 import struct |
| 74 import sys ##PY25 |
| 75 _PY2 = sys.version_info[0] < 3 ##PY25 |
| 76 from google.protobuf.internal import wire_format |
| 77 |
| 78 |
| 79 # This will overflow and thus become IEEE-754 "infinity". We would use |
| 80 # "float('inf')" but it doesn't work on Windows pre-Python-2.6. |
| 81 _POS_INF = 1e10000 |
| 82 _NEG_INF = -_POS_INF |
| 83 |
| 84 |
| 85 def _VarintSize(value): |
| 86 """Compute the size of a varint value.""" |
| 87 if value <= 0x7f: return 1 |
| 88 if value <= 0x3fff: return 2 |
| 89 if value <= 0x1fffff: return 3 |
| 90 if value <= 0xfffffff: return 4 |
| 91 if value <= 0x7ffffffff: return 5 |
| 92 if value <= 0x3ffffffffff: return 6 |
| 93 if value <= 0x1ffffffffffff: return 7 |
| 94 if value <= 0xffffffffffffff: return 8 |
| 95 if value <= 0x7fffffffffffffff: return 9 |
| 96 return 10 |
| 97 |
| 98 |
| 99 def _SignedVarintSize(value): |
| 100 """Compute the size of a signed varint value.""" |
| 101 if value < 0: return 10 |
| 102 if value <= 0x7f: return 1 |
| 103 if value <= 0x3fff: return 2 |
| 104 if value <= 0x1fffff: return 3 |
| 105 if value <= 0xfffffff: return 4 |
| 106 if value <= 0x7ffffffff: return 5 |
| 107 if value <= 0x3ffffffffff: return 6 |
| 108 if value <= 0x1ffffffffffff: return 7 |
| 109 if value <= 0xffffffffffffff: return 8 |
| 110 if value <= 0x7fffffffffffffff: return 9 |
| 111 return 10 |
| 112 |
| 113 |
| 114 def _TagSize(field_number): |
| 115 """Returns the number of bytes required to serialize a tag with this field |
| 116 number.""" |
| 117 # Just pass in type 0, since the type won't affect the tag+type size. |
| 118 return _VarintSize(wire_format.PackTag(field_number, 0)) |
| 119 |
| 120 |
| 121 # -------------------------------------------------------------------- |
| 122 # In this section we define some generic sizers. Each of these functions |
| 123 # takes parameters specific to a particular field type, e.g. int32 or fixed64. |
| 124 # It returns another function which in turn takes parameters specific to a |
| 125 # particular field, e.g. the field number and whether it is repeated or packed. |
| 126 # Look at the next section to see how these are used. |
| 127 |
| 128 |
| 129 def _SimpleSizer(compute_value_size): |
| 130 """A sizer which uses the function compute_value_size to compute the size of |
| 131 each value. Typically compute_value_size is _VarintSize.""" |
| 132 |
| 133 def SpecificSizer(field_number, is_repeated, is_packed): |
| 134 tag_size = _TagSize(field_number) |
| 135 if is_packed: |
| 136 local_VarintSize = _VarintSize |
| 137 def PackedFieldSize(value): |
| 138 result = 0 |
| 139 for element in value: |
| 140 result += compute_value_size(element) |
| 141 return result + local_VarintSize(result) + tag_size |
| 142 return PackedFieldSize |
| 143 elif is_repeated: |
| 144 def RepeatedFieldSize(value): |
| 145 result = tag_size * len(value) |
| 146 for element in value: |
| 147 result += compute_value_size(element) |
| 148 return result |
| 149 return RepeatedFieldSize |
| 150 else: |
| 151 def FieldSize(value): |
| 152 return tag_size + compute_value_size(value) |
| 153 return FieldSize |
| 154 |
| 155 return SpecificSizer |
| 156 |
| 157 |
| 158 def _ModifiedSizer(compute_value_size, modify_value): |
| 159 """Like SimpleSizer, but modify_value is invoked on each value before it is |
| 160 passed to compute_value_size. modify_value is typically ZigZagEncode.""" |
| 161 |
| 162 def SpecificSizer(field_number, is_repeated, is_packed): |
| 163 tag_size = _TagSize(field_number) |
| 164 if is_packed: |
| 165 local_VarintSize = _VarintSize |
| 166 def PackedFieldSize(value): |
| 167 result = 0 |
| 168 for element in value: |
| 169 result += compute_value_size(modify_value(element)) |
| 170 return result + local_VarintSize(result) + tag_size |
| 171 return PackedFieldSize |
| 172 elif is_repeated: |
| 173 def RepeatedFieldSize(value): |
| 174 result = tag_size * len(value) |
| 175 for element in value: |
| 176 result += compute_value_size(modify_value(element)) |
| 177 return result |
| 178 return RepeatedFieldSize |
| 179 else: |
| 180 def FieldSize(value): |
| 181 return tag_size + compute_value_size(modify_value(value)) |
| 182 return FieldSize |
| 183 |
| 184 return SpecificSizer |
| 185 |
| 186 |
| 187 def _FixedSizer(value_size): |
| 188 """Like _SimpleSizer except for a fixed-size field. The input is the size |
| 189 of one value.""" |
| 190 |
| 191 def SpecificSizer(field_number, is_repeated, is_packed): |
| 192 tag_size = _TagSize(field_number) |
| 193 if is_packed: |
| 194 local_VarintSize = _VarintSize |
| 195 def PackedFieldSize(value): |
| 196 result = len(value) * value_size |
| 197 return result + local_VarintSize(result) + tag_size |
| 198 return PackedFieldSize |
| 199 elif is_repeated: |
| 200 element_size = value_size + tag_size |
| 201 def RepeatedFieldSize(value): |
| 202 return len(value) * element_size |
| 203 return RepeatedFieldSize |
| 204 else: |
| 205 field_size = value_size + tag_size |
| 206 def FieldSize(value): |
| 207 return field_size |
| 208 return FieldSize |
| 209 |
| 210 return SpecificSizer |
| 211 |
| 212 |
| 213 # ==================================================================== |
| 214 # Here we declare a sizer constructor for each field type. Each "sizer |
| 215 # constructor" is a function that takes (field_number, is_repeated, is_packed) |
| 216 # as parameters and returns a sizer, which in turn takes a field value as |
| 217 # a parameter and returns its encoded size. |
| 218 |
| 219 |
| 220 Int32Sizer = Int64Sizer = EnumSizer = _SimpleSizer(_SignedVarintSize) |
| 221 |
| 222 UInt32Sizer = UInt64Sizer = _SimpleSizer(_VarintSize) |
| 223 |
| 224 SInt32Sizer = SInt64Sizer = _ModifiedSizer( |
| 225 _SignedVarintSize, wire_format.ZigZagEncode) |
| 226 |
| 227 Fixed32Sizer = SFixed32Sizer = FloatSizer = _FixedSizer(4) |
| 228 Fixed64Sizer = SFixed64Sizer = DoubleSizer = _FixedSizer(8) |
| 229 |
| 230 BoolSizer = _FixedSizer(1) |
| 231 |
| 232 |
| 233 def StringSizer(field_number, is_repeated, is_packed): |
| 234 """Returns a sizer for a string field.""" |
| 235 |
| 236 tag_size = _TagSize(field_number) |
| 237 local_VarintSize = _VarintSize |
| 238 local_len = len |
| 239 assert not is_packed |
| 240 if is_repeated: |
| 241 def RepeatedFieldSize(value): |
| 242 result = tag_size * len(value) |
| 243 for element in value: |
| 244 l = local_len(element.encode('utf-8')) |
| 245 result += local_VarintSize(l) + l |
| 246 return result |
| 247 return RepeatedFieldSize |
| 248 else: |
| 249 def FieldSize(value): |
| 250 l = local_len(value.encode('utf-8')) |
| 251 return tag_size + local_VarintSize(l) + l |
| 252 return FieldSize |
| 253 |
| 254 |
| 255 def BytesSizer(field_number, is_repeated, is_packed): |
| 256 """Returns a sizer for a bytes field.""" |
| 257 |
| 258 tag_size = _TagSize(field_number) |
| 259 local_VarintSize = _VarintSize |
| 260 local_len = len |
| 261 assert not is_packed |
| 262 if is_repeated: |
| 263 def RepeatedFieldSize(value): |
| 264 result = tag_size * len(value) |
| 265 for element in value: |
| 266 l = local_len(element) |
| 267 result += local_VarintSize(l) + l |
| 268 return result |
| 269 return RepeatedFieldSize |
| 270 else: |
| 271 def FieldSize(value): |
| 272 l = local_len(value) |
| 273 return tag_size + local_VarintSize(l) + l |
| 274 return FieldSize |
| 275 |
| 276 |
| 277 def GroupSizer(field_number, is_repeated, is_packed): |
| 278 """Returns a sizer for a group field.""" |
| 279 |
| 280 tag_size = _TagSize(field_number) * 2 |
| 281 assert not is_packed |
| 282 if is_repeated: |
| 283 def RepeatedFieldSize(value): |
| 284 result = tag_size * len(value) |
| 285 for element in value: |
| 286 result += element.ByteSize() |
| 287 return result |
| 288 return RepeatedFieldSize |
| 289 else: |
| 290 def FieldSize(value): |
| 291 return tag_size + value.ByteSize() |
| 292 return FieldSize |
| 293 |
| 294 |
| 295 def MessageSizer(field_number, is_repeated, is_packed): |
| 296 """Returns a sizer for a message field.""" |
| 297 |
| 298 tag_size = _TagSize(field_number) |
| 299 local_VarintSize = _VarintSize |
| 300 assert not is_packed |
| 301 if is_repeated: |
| 302 def RepeatedFieldSize(value): |
| 303 result = tag_size * len(value) |
| 304 for element in value: |
| 305 l = element.ByteSize() |
| 306 result += local_VarintSize(l) + l |
| 307 return result |
| 308 return RepeatedFieldSize |
| 309 else: |
| 310 def FieldSize(value): |
| 311 l = value.ByteSize() |
| 312 return tag_size + local_VarintSize(l) + l |
| 313 return FieldSize |
| 314 |
| 315 |
| 316 # -------------------------------------------------------------------- |
| 317 # MessageSet is special. |
| 318 |
| 319 |
| 320 def MessageSetItemSizer(field_number): |
| 321 """Returns a sizer for extensions of MessageSet. |
| 322 |
| 323 The message set message looks like this: |
| 324 message MessageSet { |
| 325 repeated group Item = 1 { |
| 326 required int32 type_id = 2; |
| 327 required string message = 3; |
| 328 } |
| 329 } |
| 330 """ |
| 331 static_size = (_TagSize(1) * 2 + _TagSize(2) + _VarintSize(field_number) + |
| 332 _TagSize(3)) |
| 333 local_VarintSize = _VarintSize |
| 334 |
| 335 def FieldSize(value): |
| 336 l = value.ByteSize() |
| 337 return static_size + local_VarintSize(l) + l |
| 338 |
| 339 return FieldSize |
| 340 |
| 341 |
| 342 # ==================================================================== |
| 343 # Encoders! |
| 344 |
| 345 |
| 346 def _VarintEncoder(): |
| 347 """Return an encoder for a basic varint value (does not include tag).""" |
| 348 |
| 349 local_chr = _PY2 and chr or (lambda x: bytes((x,))) ##PY25 |
| 350 ##!PY25 local_chr = chr if bytes is str else lambda x: bytes((x,)) |
| 351 def EncodeVarint(write, value): |
| 352 bits = value & 0x7f |
| 353 value >>= 7 |
| 354 while value: |
| 355 write(local_chr(0x80|bits)) |
| 356 bits = value & 0x7f |
| 357 value >>= 7 |
| 358 return write(local_chr(bits)) |
| 359 |
| 360 return EncodeVarint |
| 361 |
| 362 |
| 363 def _SignedVarintEncoder(): |
| 364 """Return an encoder for a basic signed varint value (does not include |
| 365 tag).""" |
| 366 |
| 367 local_chr = _PY2 and chr or (lambda x: bytes((x,))) ##PY25 |
| 368 ##!PY25 local_chr = chr if bytes is str else lambda x: bytes((x,)) |
| 369 def EncodeSignedVarint(write, value): |
| 370 if value < 0: |
| 371 value += (1 << 64) |
| 372 bits = value & 0x7f |
| 373 value >>= 7 |
| 374 while value: |
| 375 write(local_chr(0x80|bits)) |
| 376 bits = value & 0x7f |
| 377 value >>= 7 |
| 378 return write(local_chr(bits)) |
| 379 |
| 380 return EncodeSignedVarint |
| 381 |
| 382 |
| 383 _EncodeVarint = _VarintEncoder() |
| 384 _EncodeSignedVarint = _SignedVarintEncoder() |
| 385 |
| 386 |
| 387 def _VarintBytes(value): |
| 388 """Encode the given integer as a varint and return the bytes. This is only |
| 389 called at startup time so it doesn't need to be fast.""" |
| 390 |
| 391 pieces = [] |
| 392 _EncodeVarint(pieces.append, value) |
| 393 return "".encode("latin1").join(pieces) ##PY25 |
| 394 ##!PY25 return b"".join(pieces) |
| 395 |
| 396 |
| 397 def TagBytes(field_number, wire_type): |
| 398 """Encode the given tag and return the bytes. Only called at startup.""" |
| 399 |
| 400 return _VarintBytes(wire_format.PackTag(field_number, wire_type)) |
| 401 |
| 402 # -------------------------------------------------------------------- |
| 403 # As with sizers (see above), we have a number of common encoder |
| 404 # implementations. |
| 405 |
| 406 |
| 407 def _SimpleEncoder(wire_type, encode_value, compute_value_size): |
| 408 """Return a constructor for an encoder for fields of a particular type. |
| 409 |
| 410 Args: |
| 411 wire_type: The field's wire type, for encoding tags. |
| 412 encode_value: A function which encodes an individual value, e.g. |
| 413 _EncodeVarint(). |
| 414 compute_value_size: A function which computes the size of an individual |
| 415 value, e.g. _VarintSize(). |
| 416 """ |
| 417 |
| 418 def SpecificEncoder(field_number, is_repeated, is_packed): |
| 419 if is_packed: |
| 420 tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED) |
| 421 local_EncodeVarint = _EncodeVarint |
| 422 def EncodePackedField(write, value): |
| 423 write(tag_bytes) |
| 424 size = 0 |
| 425 for element in value: |
| 426 size += compute_value_size(element) |
| 427 local_EncodeVarint(write, size) |
| 428 for element in value: |
| 429 encode_value(write, element) |
| 430 return EncodePackedField |
| 431 elif is_repeated: |
| 432 tag_bytes = TagBytes(field_number, wire_type) |
| 433 def EncodeRepeatedField(write, value): |
| 434 for element in value: |
| 435 write(tag_bytes) |
| 436 encode_value(write, element) |
| 437 return EncodeRepeatedField |
| 438 else: |
| 439 tag_bytes = TagBytes(field_number, wire_type) |
| 440 def EncodeField(write, value): |
| 441 write(tag_bytes) |
| 442 return encode_value(write, value) |
| 443 return EncodeField |
| 444 |
| 445 return SpecificEncoder |
| 446 |
| 447 |
| 448 def _ModifiedEncoder(wire_type, encode_value, compute_value_size, modify_value): |
| 449 """Like SimpleEncoder but additionally invokes modify_value on every value |
| 450 before passing it to encode_value. Usually modify_value is ZigZagEncode.""" |
| 451 |
| 452 def SpecificEncoder(field_number, is_repeated, is_packed): |
| 453 if is_packed: |
| 454 tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED) |
| 455 local_EncodeVarint = _EncodeVarint |
| 456 def EncodePackedField(write, value): |
| 457 write(tag_bytes) |
| 458 size = 0 |
| 459 for element in value: |
| 460 size += compute_value_size(modify_value(element)) |
| 461 local_EncodeVarint(write, size) |
| 462 for element in value: |
| 463 encode_value(write, modify_value(element)) |
| 464 return EncodePackedField |
| 465 elif is_repeated: |
| 466 tag_bytes = TagBytes(field_number, wire_type) |
| 467 def EncodeRepeatedField(write, value): |
| 468 for element in value: |
| 469 write(tag_bytes) |
| 470 encode_value(write, modify_value(element)) |
| 471 return EncodeRepeatedField |
| 472 else: |
| 473 tag_bytes = TagBytes(field_number, wire_type) |
| 474 def EncodeField(write, value): |
| 475 write(tag_bytes) |
| 476 return encode_value(write, modify_value(value)) |
| 477 return EncodeField |
| 478 |
| 479 return SpecificEncoder |
| 480 |
| 481 |
| 482 def _StructPackEncoder(wire_type, format): |
| 483 """Return a constructor for an encoder for a fixed-width field. |
| 484 |
| 485 Args: |
| 486 wire_type: The field's wire type, for encoding tags. |
| 487 format: The format string to pass to struct.pack(). |
| 488 """ |
| 489 |
| 490 value_size = struct.calcsize(format) |
| 491 |
| 492 def SpecificEncoder(field_number, is_repeated, is_packed): |
| 493 local_struct_pack = struct.pack |
| 494 if is_packed: |
| 495 tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED) |
| 496 local_EncodeVarint = _EncodeVarint |
| 497 def EncodePackedField(write, value): |
| 498 write(tag_bytes) |
| 499 local_EncodeVarint(write, len(value) * value_size) |
| 500 for element in value: |
| 501 write(local_struct_pack(format, element)) |
| 502 return EncodePackedField |
| 503 elif is_repeated: |
| 504 tag_bytes = TagBytes(field_number, wire_type) |
| 505 def EncodeRepeatedField(write, value): |
| 506 for element in value: |
| 507 write(tag_bytes) |
| 508 write(local_struct_pack(format, element)) |
| 509 return EncodeRepeatedField |
| 510 else: |
| 511 tag_bytes = TagBytes(field_number, wire_type) |
| 512 def EncodeField(write, value): |
| 513 write(tag_bytes) |
| 514 return write(local_struct_pack(format, value)) |
| 515 return EncodeField |
| 516 |
| 517 return SpecificEncoder |
| 518 |
| 519 |
| 520 def _FloatingPointEncoder(wire_type, format): |
| 521 """Return a constructor for an encoder for float fields. |
| 522 |
| 523 This is like StructPackEncoder, but catches errors that may be due to |
| 524 passing non-finite floating-point values to struct.pack, and makes a |
| 525 second attempt to encode those values. |
| 526 |
| 527 Args: |
| 528 wire_type: The field's wire type, for encoding tags. |
| 529 format: The format string to pass to struct.pack(). |
| 530 """ |
| 531 |
| 532 b = _PY2 and (lambda x:x) or (lambda x:x.encode('latin1')) ##PY25 |
| 533 value_size = struct.calcsize(format) |
| 534 if value_size == 4: |
| 535 def EncodeNonFiniteOrRaise(write, value): |
| 536 # Remember that the serialized form uses little-endian byte order. |
| 537 if value == _POS_INF: |
| 538 write(b('\x00\x00\x80\x7F')) ##PY25 |
| 539 ##!PY25 write(b'\x00\x00\x80\x7F') |
| 540 elif value == _NEG_INF: |
| 541 write(b('\x00\x00\x80\xFF')) ##PY25 |
| 542 ##!PY25 write(b'\x00\x00\x80\xFF') |
| 543 elif value != value: # NaN |
| 544 write(b('\x00\x00\xC0\x7F')) ##PY25 |
| 545 ##!PY25 write(b'\x00\x00\xC0\x7F') |
| 546 else: |
| 547 raise |
| 548 elif value_size == 8: |
| 549 def EncodeNonFiniteOrRaise(write, value): |
| 550 if value == _POS_INF: |
| 551 write(b('\x00\x00\x00\x00\x00\x00\xF0\x7F')) ##PY25 |
| 552 ##!PY25 write(b'\x00\x00\x00\x00\x00\x00\xF0\x7F') |
| 553 elif value == _NEG_INF: |
| 554 write(b('\x00\x00\x00\x00\x00\x00\xF0\xFF')) ##PY25 |
| 555 ##!PY25 write(b'\x00\x00\x00\x00\x00\x00\xF0\xFF') |
| 556 elif value != value: # NaN |
| 557 write(b('\x00\x00\x00\x00\x00\x00\xF8\x7F')) ##PY25 |
| 558 ##!PY25 write(b'\x00\x00\x00\x00\x00\x00\xF8\x7F') |
| 559 else: |
| 560 raise |
| 561 else: |
| 562 raise ValueError('Can\'t encode floating-point values that are ' |
| 563 '%d bytes long (only 4 or 8)' % value_size) |
| 564 |
| 565 def SpecificEncoder(field_number, is_repeated, is_packed): |
| 566 local_struct_pack = struct.pack |
| 567 if is_packed: |
| 568 tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED) |
| 569 local_EncodeVarint = _EncodeVarint |
| 570 def EncodePackedField(write, value): |
| 571 write(tag_bytes) |
| 572 local_EncodeVarint(write, len(value) * value_size) |
| 573 for element in value: |
| 574 # This try/except block is going to be faster than any code that |
| 575 # we could write to check whether element is finite. |
| 576 try: |
| 577 write(local_struct_pack(format, element)) |
| 578 except SystemError: |
| 579 EncodeNonFiniteOrRaise(write, element) |
| 580 return EncodePackedField |
| 581 elif is_repeated: |
| 582 tag_bytes = TagBytes(field_number, wire_type) |
| 583 def EncodeRepeatedField(write, value): |
| 584 for element in value: |
| 585 write(tag_bytes) |
| 586 try: |
| 587 write(local_struct_pack(format, element)) |
| 588 except SystemError: |
| 589 EncodeNonFiniteOrRaise(write, element) |
| 590 return EncodeRepeatedField |
| 591 else: |
| 592 tag_bytes = TagBytes(field_number, wire_type) |
| 593 def EncodeField(write, value): |
| 594 write(tag_bytes) |
| 595 try: |
| 596 write(local_struct_pack(format, value)) |
| 597 except SystemError: |
| 598 EncodeNonFiniteOrRaise(write, value) |
| 599 return EncodeField |
| 600 |
| 601 return SpecificEncoder |
| 602 |
| 603 |
| 604 # ==================================================================== |
| 605 # Here we declare an encoder constructor for each field type. These work |
| 606 # very similarly to sizer constructors, described earlier. |
| 607 |
| 608 |
| 609 Int32Encoder = Int64Encoder = EnumEncoder = _SimpleEncoder( |
| 610 wire_format.WIRETYPE_VARINT, _EncodeSignedVarint, _SignedVarintSize) |
| 611 |
| 612 UInt32Encoder = UInt64Encoder = _SimpleEncoder( |
| 613 wire_format.WIRETYPE_VARINT, _EncodeVarint, _VarintSize) |
| 614 |
| 615 SInt32Encoder = SInt64Encoder = _ModifiedEncoder( |
| 616 wire_format.WIRETYPE_VARINT, _EncodeVarint, _VarintSize, |
| 617 wire_format.ZigZagEncode) |
| 618 |
| 619 # Note that Python conveniently guarantees that when using the '<' prefix on |
| 620 # formats, they will also have the same size across all platforms (as opposed |
| 621 # to without the prefix, where their sizes depend on the C compiler's basic |
| 622 # type sizes). |
| 623 Fixed32Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, '<I') |
| 624 Fixed64Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, '<Q') |
| 625 SFixed32Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, '<i') |
| 626 SFixed64Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, '<q') |
| 627 FloatEncoder = _FloatingPointEncoder(wire_format.WIRETYPE_FIXED32, '<f') |
| 628 DoubleEncoder = _FloatingPointEncoder(wire_format.WIRETYPE_FIXED64, '<d') |
| 629 |
| 630 |
| 631 def BoolEncoder(field_number, is_repeated, is_packed): |
| 632 """Returns an encoder for a boolean field.""" |
| 633 |
| 634 ##!PY25 false_byte = b'\x00' |
| 635 ##!PY25 true_byte = b'\x01' |
| 636 false_byte = '\x00'.encode('latin1') ##PY25 |
| 637 true_byte = '\x01'.encode('latin1') ##PY25 |
| 638 if is_packed: |
| 639 tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED) |
| 640 local_EncodeVarint = _EncodeVarint |
| 641 def EncodePackedField(write, value): |
| 642 write(tag_bytes) |
| 643 local_EncodeVarint(write, len(value)) |
| 644 for element in value: |
| 645 if element: |
| 646 write(true_byte) |
| 647 else: |
| 648 write(false_byte) |
| 649 return EncodePackedField |
| 650 elif is_repeated: |
| 651 tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_VARINT) |
| 652 def EncodeRepeatedField(write, value): |
| 653 for element in value: |
| 654 write(tag_bytes) |
| 655 if element: |
| 656 write(true_byte) |
| 657 else: |
| 658 write(false_byte) |
| 659 return EncodeRepeatedField |
| 660 else: |
| 661 tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_VARINT) |
| 662 def EncodeField(write, value): |
| 663 write(tag_bytes) |
| 664 if value: |
| 665 return write(true_byte) |
| 666 return write(false_byte) |
| 667 return EncodeField |
| 668 |
| 669 |
| 670 def StringEncoder(field_number, is_repeated, is_packed): |
| 671 """Returns an encoder for a string field.""" |
| 672 |
| 673 tag = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED) |
| 674 local_EncodeVarint = _EncodeVarint |
| 675 local_len = len |
| 676 assert not is_packed |
| 677 if is_repeated: |
| 678 def EncodeRepeatedField(write, value): |
| 679 for element in value: |
| 680 encoded = element.encode('utf-8') |
| 681 write(tag) |
| 682 local_EncodeVarint(write, local_len(encoded)) |
| 683 write(encoded) |
| 684 return EncodeRepeatedField |
| 685 else: |
| 686 def EncodeField(write, value): |
| 687 encoded = value.encode('utf-8') |
| 688 write(tag) |
| 689 local_EncodeVarint(write, local_len(encoded)) |
| 690 return write(encoded) |
| 691 return EncodeField |
| 692 |
| 693 |
| 694 def BytesEncoder(field_number, is_repeated, is_packed): |
| 695 """Returns an encoder for a bytes field.""" |
| 696 |
| 697 tag = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED) |
| 698 local_EncodeVarint = _EncodeVarint |
| 699 local_len = len |
| 700 assert not is_packed |
| 701 if is_repeated: |
| 702 def EncodeRepeatedField(write, value): |
| 703 for element in value: |
| 704 write(tag) |
| 705 local_EncodeVarint(write, local_len(element)) |
| 706 write(element) |
| 707 return EncodeRepeatedField |
| 708 else: |
| 709 def EncodeField(write, value): |
| 710 write(tag) |
| 711 local_EncodeVarint(write, local_len(value)) |
| 712 return write(value) |
| 713 return EncodeField |
| 714 |
| 715 |
| 716 def GroupEncoder(field_number, is_repeated, is_packed): |
| 717 """Returns an encoder for a group field.""" |
| 718 |
| 719 start_tag = TagBytes(field_number, wire_format.WIRETYPE_START_GROUP) |
| 720 end_tag = TagBytes(field_number, wire_format.WIRETYPE_END_GROUP) |
| 721 assert not is_packed |
| 722 if is_repeated: |
| 723 def EncodeRepeatedField(write, value): |
| 724 for element in value: |
| 725 write(start_tag) |
| 726 element._InternalSerialize(write) |
| 727 write(end_tag) |
| 728 return EncodeRepeatedField |
| 729 else: |
| 730 def EncodeField(write, value): |
| 731 write(start_tag) |
| 732 value._InternalSerialize(write) |
| 733 return write(end_tag) |
| 734 return EncodeField |
| 735 |
| 736 |
| 737 def MessageEncoder(field_number, is_repeated, is_packed): |
| 738 """Returns an encoder for a message field.""" |
| 739 |
| 740 tag = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED) |
| 741 local_EncodeVarint = _EncodeVarint |
| 742 assert not is_packed |
| 743 if is_repeated: |
| 744 def EncodeRepeatedField(write, value): |
| 745 for element in value: |
| 746 write(tag) |
| 747 local_EncodeVarint(write, element.ByteSize()) |
| 748 element._InternalSerialize(write) |
| 749 return EncodeRepeatedField |
| 750 else: |
| 751 def EncodeField(write, value): |
| 752 write(tag) |
| 753 local_EncodeVarint(write, value.ByteSize()) |
| 754 return value._InternalSerialize(write) |
| 755 return EncodeField |
| 756 |
| 757 |
| 758 # -------------------------------------------------------------------- |
| 759 # As before, MessageSet is special. |
| 760 |
| 761 |
| 762 def MessageSetItemEncoder(field_number): |
| 763 """Encoder for extensions of MessageSet. |
| 764 |
| 765 The message set message looks like this: |
| 766 message MessageSet { |
| 767 repeated group Item = 1 { |
| 768 required int32 type_id = 2; |
| 769 required string message = 3; |
| 770 } |
| 771 } |
| 772 """ |
| 773 start_bytes = "".encode("latin1").join([ ##PY25 |
| 774 ##!PY25 start_bytes = b"".join([ |
| 775 TagBytes(1, wire_format.WIRETYPE_START_GROUP), |
| 776 TagBytes(2, wire_format.WIRETYPE_VARINT), |
| 777 _VarintBytes(field_number), |
| 778 TagBytes(3, wire_format.WIRETYPE_LENGTH_DELIMITED)]) |
| 779 end_bytes = TagBytes(1, wire_format.WIRETYPE_END_GROUP) |
| 780 local_EncodeVarint = _EncodeVarint |
| 781 |
| 782 def EncodeField(write, value): |
| 783 write(start_bytes) |
| 784 local_EncodeVarint(write, value.ByteSize()) |
| 785 value._InternalSerialize(write) |
| 786 return write(end_bytes) |
| 787 |
| 788 return EncodeField |
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