Spaces:
Running
Running
File size: 38,596 Bytes
375a1cf |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 |
# Protocol Buffers - Google's data interchange format
# Copyright 2008 Google Inc. All rights reserved.
# https://developers.google.com/protocol-buffers/
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
# * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""Code for decoding protocol buffer primitives.
This code is very similar to encoder.py -- read the docs for that module first.
A "decoder" is a function with the signature:
Decode(buffer, pos, end, message, field_dict)
The arguments are:
buffer: The string containing the encoded message.
pos: The current position in the string.
end: The position in the string where the current message ends. May be
less than len(buffer) if we're reading a sub-message.
message: The message object into which we're parsing.
field_dict: message._fields (avoids a hashtable lookup).
The decoder reads the field and stores it into field_dict, returning the new
buffer position. A decoder for a repeated field may proactively decode all of
the elements of that field, if they appear consecutively.
Note that decoders may throw any of the following:
IndexError: Indicates a truncated message.
struct.error: Unpacking of a fixed-width field failed.
message.DecodeError: Other errors.
Decoders are expected to raise an exception if they are called with pos > end.
This allows callers to be lax about bounds checking: it's fineto read past
"end" as long as you are sure that someone else will notice and throw an
exception later on.
Something up the call stack is expected to catch IndexError and struct.error
and convert them to message.DecodeError.
Decoders are constructed using decoder constructors with the signature:
MakeDecoder(field_number, is_repeated, is_packed, key, new_default)
The arguments are:
field_number: The field number of the field we want to decode.
is_repeated: Is the field a repeated field? (bool)
is_packed: Is the field a packed field? (bool)
key: The key to use when looking up the field within field_dict.
(This is actually the FieldDescriptor but nothing in this
file should depend on that.)
new_default: A function which takes a message object as a parameter and
returns a new instance of the default value for this field.
(This is called for repeated fields and sub-messages, when an
instance does not already exist.)
As with encoders, we define a decoder constructor for every type of field.
Then, for every field of every message class we construct an actual decoder.
That decoder goes into a dict indexed by tag, so when we decode a message
we repeatedly read a tag, look up the corresponding decoder, and invoke it.
"""
__author__ = '[email protected] (Kenton Varda)'
import math
import struct
from google.protobuf.internal import containers
from google.protobuf.internal import encoder
from google.protobuf.internal import wire_format
from google.protobuf import message
# This is not for optimization, but rather to avoid conflicts with local
# variables named "message".
_DecodeError = message.DecodeError
def _VarintDecoder(mask, result_type):
"""Return an encoder for a basic varint value (does not include tag).
Decoded values will be bitwise-anded with the given mask before being
returned, e.g. to limit them to 32 bits. The returned decoder does not
take the usual "end" parameter -- the caller is expected to do bounds checking
after the fact (often the caller can defer such checking until later). The
decoder returns a (value, new_pos) pair.
"""
def DecodeVarint(buffer, pos):
result = 0
shift = 0
while 1:
b = buffer[pos]
result |= ((b & 0x7f) << shift)
pos += 1
if not (b & 0x80):
result &= mask
result = result_type(result)
return (result, pos)
shift += 7
if shift >= 64:
raise _DecodeError('Too many bytes when decoding varint.')
return DecodeVarint
def _SignedVarintDecoder(bits, result_type):
"""Like _VarintDecoder() but decodes signed values."""
signbit = 1 << (bits - 1)
mask = (1 << bits) - 1
def DecodeVarint(buffer, pos):
result = 0
shift = 0
while 1:
b = buffer[pos]
result |= ((b & 0x7f) << shift)
pos += 1
if not (b & 0x80):
result &= mask
result = (result ^ signbit) - signbit
result = result_type(result)
return (result, pos)
shift += 7
if shift >= 64:
raise _DecodeError('Too many bytes when decoding varint.')
return DecodeVarint
# All 32-bit and 64-bit values are represented as int.
_DecodeVarint = _VarintDecoder((1 << 64) - 1, int)
_DecodeSignedVarint = _SignedVarintDecoder(64, int)
# Use these versions for values which must be limited to 32 bits.
_DecodeVarint32 = _VarintDecoder((1 << 32) - 1, int)
_DecodeSignedVarint32 = _SignedVarintDecoder(32, int)
def ReadTag(buffer, pos):
"""Read a tag from the memoryview, and return a (tag_bytes, new_pos) tuple.
We return the raw bytes of the tag rather than decoding them. The raw
bytes can then be used to look up the proper decoder. This effectively allows
us to trade some work that would be done in pure-python (decoding a varint)
for work that is done in C (searching for a byte string in a hash table).
In a low-level language it would be much cheaper to decode the varint and
use that, but not in Python.
Args:
buffer: memoryview object of the encoded bytes
pos: int of the current position to start from
Returns:
Tuple[bytes, int] of the tag data and new position.
"""
start = pos
while buffer[pos] & 0x80:
pos += 1
pos += 1
tag_bytes = buffer[start:pos].tobytes()
return tag_bytes, pos
# --------------------------------------------------------------------
def _SimpleDecoder(wire_type, decode_value):
"""Return a constructor for a decoder for fields of a particular type.
Args:
wire_type: The field's wire type.
decode_value: A function which decodes an individual value, e.g.
_DecodeVarint()
"""
def SpecificDecoder(field_number, is_repeated, is_packed, key, new_default,
clear_if_default=False):
if is_packed:
local_DecodeVarint = _DecodeVarint
def DecodePackedField(buffer, pos, end, message, field_dict):
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
(endpoint, pos) = local_DecodeVarint(buffer, pos)
endpoint += pos
if endpoint > end:
raise _DecodeError('Truncated message.')
while pos < endpoint:
(element, pos) = decode_value(buffer, pos)
value.append(element)
if pos > endpoint:
del value[-1] # Discard corrupt value.
raise _DecodeError('Packed element was truncated.')
return pos
return DecodePackedField
elif is_repeated:
tag_bytes = encoder.TagBytes(field_number, wire_type)
tag_len = len(tag_bytes)
def DecodeRepeatedField(buffer, pos, end, message, field_dict):
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
while 1:
(element, new_pos) = decode_value(buffer, pos)
value.append(element)
# Predict that the next tag is another copy of the same repeated
# field.
pos = new_pos + tag_len
if buffer[new_pos:pos] != tag_bytes or new_pos >= end:
# Prediction failed. Return.
if new_pos > end:
raise _DecodeError('Truncated message.')
return new_pos
return DecodeRepeatedField
else:
def DecodeField(buffer, pos, end, message, field_dict):
(new_value, pos) = decode_value(buffer, pos)
if pos > end:
raise _DecodeError('Truncated message.')
if clear_if_default and not new_value:
field_dict.pop(key, None)
else:
field_dict[key] = new_value
return pos
return DecodeField
return SpecificDecoder
def _ModifiedDecoder(wire_type, decode_value, modify_value):
"""Like SimpleDecoder but additionally invokes modify_value on every value
before storing it. Usually modify_value is ZigZagDecode.
"""
# Reusing _SimpleDecoder is slightly slower than copying a bunch of code, but
# not enough to make a significant difference.
def InnerDecode(buffer, pos):
(result, new_pos) = decode_value(buffer, pos)
return (modify_value(result), new_pos)
return _SimpleDecoder(wire_type, InnerDecode)
def _StructPackDecoder(wire_type, format):
"""Return a constructor for a decoder for a fixed-width field.
Args:
wire_type: The field's wire type.
format: The format string to pass to struct.unpack().
"""
value_size = struct.calcsize(format)
local_unpack = struct.unpack
# Reusing _SimpleDecoder is slightly slower than copying a bunch of code, but
# not enough to make a significant difference.
# Note that we expect someone up-stack to catch struct.error and convert
# it to _DecodeError -- this way we don't have to set up exception-
# handling blocks every time we parse one value.
def InnerDecode(buffer, pos):
new_pos = pos + value_size
result = local_unpack(format, buffer[pos:new_pos])[0]
return (result, new_pos)
return _SimpleDecoder(wire_type, InnerDecode)
def _FloatDecoder():
"""Returns a decoder for a float field.
This code works around a bug in struct.unpack for non-finite 32-bit
floating-point values.
"""
local_unpack = struct.unpack
def InnerDecode(buffer, pos):
"""Decode serialized float to a float and new position.
Args:
buffer: memoryview of the serialized bytes
pos: int, position in the memory view to start at.
Returns:
Tuple[float, int] of the deserialized float value and new position
in the serialized data.
"""
# We expect a 32-bit value in little-endian byte order. Bit 1 is the sign
# bit, bits 2-9 represent the exponent, and bits 10-32 are the significand.
new_pos = pos + 4
float_bytes = buffer[pos:new_pos].tobytes()
# If this value has all its exponent bits set, then it's non-finite.
# In Python 2.4, struct.unpack will convert it to a finite 64-bit value.
# To avoid that, we parse it specially.
if (float_bytes[3:4] in b'\x7F\xFF' and float_bytes[2:3] >= b'\x80'):
# If at least one significand bit is set...
if float_bytes[0:3] != b'\x00\x00\x80':
return (math.nan, new_pos)
# If sign bit is set...
if float_bytes[3:4] == b'\xFF':
return (-math.inf, new_pos)
return (math.inf, new_pos)
# Note that we expect someone up-stack to catch struct.error and convert
# it to _DecodeError -- this way we don't have to set up exception-
# handling blocks every time we parse one value.
result = local_unpack('<f', float_bytes)[0]
return (result, new_pos)
return _SimpleDecoder(wire_format.WIRETYPE_FIXED32, InnerDecode)
def _DoubleDecoder():
"""Returns a decoder for a double field.
This code works around a bug in struct.unpack for not-a-number.
"""
local_unpack = struct.unpack
def InnerDecode(buffer, pos):
"""Decode serialized double to a double and new position.
Args:
buffer: memoryview of the serialized bytes.
pos: int, position in the memory view to start at.
Returns:
Tuple[float, int] of the decoded double value and new position
in the serialized data.
"""
# We expect a 64-bit value in little-endian byte order. Bit 1 is the sign
# bit, bits 2-12 represent the exponent, and bits 13-64 are the significand.
new_pos = pos + 8
double_bytes = buffer[pos:new_pos].tobytes()
# If this value has all its exponent bits set and at least one significand
# bit set, it's not a number. In Python 2.4, struct.unpack will treat it
# as inf or -inf. To avoid that, we treat it specially.
if ((double_bytes[7:8] in b'\x7F\xFF')
and (double_bytes[6:7] >= b'\xF0')
and (double_bytes[0:7] != b'\x00\x00\x00\x00\x00\x00\xF0')):
return (math.nan, new_pos)
# Note that we expect someone up-stack to catch struct.error and convert
# it to _DecodeError -- this way we don't have to set up exception-
# handling blocks every time we parse one value.
result = local_unpack('<d', double_bytes)[0]
return (result, new_pos)
return _SimpleDecoder(wire_format.WIRETYPE_FIXED64, InnerDecode)
def EnumDecoder(field_number, is_repeated, is_packed, key, new_default,
clear_if_default=False):
"""Returns a decoder for enum field."""
enum_type = key.enum_type
if is_packed:
local_DecodeVarint = _DecodeVarint
def DecodePackedField(buffer, pos, end, message, field_dict):
"""Decode serialized packed enum to its value and a new position.
Args:
buffer: memoryview of the serialized bytes.
pos: int, position in the memory view to start at.
end: int, end position of serialized data
message: Message object to store unknown fields in
field_dict: Map[Descriptor, Any] to store decoded values in.
Returns:
int, new position in serialized data.
"""
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
(endpoint, pos) = local_DecodeVarint(buffer, pos)
endpoint += pos
if endpoint > end:
raise _DecodeError('Truncated message.')
while pos < endpoint:
value_start_pos = pos
(element, pos) = _DecodeSignedVarint32(buffer, pos)
# pylint: disable=protected-access
if element in enum_type.values_by_number:
value.append(element)
else:
if not message._unknown_fields:
message._unknown_fields = []
tag_bytes = encoder.TagBytes(field_number,
wire_format.WIRETYPE_VARINT)
message._unknown_fields.append(
(tag_bytes, buffer[value_start_pos:pos].tobytes()))
if message._unknown_field_set is None:
message._unknown_field_set = containers.UnknownFieldSet()
message._unknown_field_set._add(
field_number, wire_format.WIRETYPE_VARINT, element)
# pylint: enable=protected-access
if pos > endpoint:
if element in enum_type.values_by_number:
del value[-1] # Discard corrupt value.
else:
del message._unknown_fields[-1]
# pylint: disable=protected-access
del message._unknown_field_set._values[-1]
# pylint: enable=protected-access
raise _DecodeError('Packed element was truncated.')
return pos
return DecodePackedField
elif is_repeated:
tag_bytes = encoder.TagBytes(field_number, wire_format.WIRETYPE_VARINT)
tag_len = len(tag_bytes)
def DecodeRepeatedField(buffer, pos, end, message, field_dict):
"""Decode serialized repeated enum to its value and a new position.
Args:
buffer: memoryview of the serialized bytes.
pos: int, position in the memory view to start at.
end: int, end position of serialized data
message: Message object to store unknown fields in
field_dict: Map[Descriptor, Any] to store decoded values in.
Returns:
int, new position in serialized data.
"""
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
while 1:
(element, new_pos) = _DecodeSignedVarint32(buffer, pos)
# pylint: disable=protected-access
if element in enum_type.values_by_number:
value.append(element)
else:
if not message._unknown_fields:
message._unknown_fields = []
message._unknown_fields.append(
(tag_bytes, buffer[pos:new_pos].tobytes()))
if message._unknown_field_set is None:
message._unknown_field_set = containers.UnknownFieldSet()
message._unknown_field_set._add(
field_number, wire_format.WIRETYPE_VARINT, element)
# pylint: enable=protected-access
# Predict that the next tag is another copy of the same repeated
# field.
pos = new_pos + tag_len
if buffer[new_pos:pos] != tag_bytes or new_pos >= end:
# Prediction failed. Return.
if new_pos > end:
raise _DecodeError('Truncated message.')
return new_pos
return DecodeRepeatedField
else:
def DecodeField(buffer, pos, end, message, field_dict):
"""Decode serialized repeated enum to its value and a new position.
Args:
buffer: memoryview of the serialized bytes.
pos: int, position in the memory view to start at.
end: int, end position of serialized data
message: Message object to store unknown fields in
field_dict: Map[Descriptor, Any] to store decoded values in.
Returns:
int, new position in serialized data.
"""
value_start_pos = pos
(enum_value, pos) = _DecodeSignedVarint32(buffer, pos)
if pos > end:
raise _DecodeError('Truncated message.')
if clear_if_default and not enum_value:
field_dict.pop(key, None)
return pos
# pylint: disable=protected-access
if enum_value in enum_type.values_by_number:
field_dict[key] = enum_value
else:
if not message._unknown_fields:
message._unknown_fields = []
tag_bytes = encoder.TagBytes(field_number,
wire_format.WIRETYPE_VARINT)
message._unknown_fields.append(
(tag_bytes, buffer[value_start_pos:pos].tobytes()))
if message._unknown_field_set is None:
message._unknown_field_set = containers.UnknownFieldSet()
message._unknown_field_set._add(
field_number, wire_format.WIRETYPE_VARINT, enum_value)
# pylint: enable=protected-access
return pos
return DecodeField
# --------------------------------------------------------------------
Int32Decoder = _SimpleDecoder(
wire_format.WIRETYPE_VARINT, _DecodeSignedVarint32)
Int64Decoder = _SimpleDecoder(
wire_format.WIRETYPE_VARINT, _DecodeSignedVarint)
UInt32Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint32)
UInt64Decoder = _SimpleDecoder(wire_format.WIRETYPE_VARINT, _DecodeVarint)
SInt32Decoder = _ModifiedDecoder(
wire_format.WIRETYPE_VARINT, _DecodeVarint32, wire_format.ZigZagDecode)
SInt64Decoder = _ModifiedDecoder(
wire_format.WIRETYPE_VARINT, _DecodeVarint, wire_format.ZigZagDecode)
# Note that Python conveniently guarantees that when using the '<' prefix on
# formats, they will also have the same size across all platforms (as opposed
# to without the prefix, where their sizes depend on the C compiler's basic
# type sizes).
Fixed32Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, '<I')
Fixed64Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, '<Q')
SFixed32Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, '<i')
SFixed64Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, '<q')
FloatDecoder = _FloatDecoder()
DoubleDecoder = _DoubleDecoder()
BoolDecoder = _ModifiedDecoder(
wire_format.WIRETYPE_VARINT, _DecodeVarint, bool)
def StringDecoder(field_number, is_repeated, is_packed, key, new_default,
clear_if_default=False):
"""Returns a decoder for a string field."""
local_DecodeVarint = _DecodeVarint
def _ConvertToUnicode(memview):
"""Convert byte to unicode."""
byte_str = memview.tobytes()
try:
value = str(byte_str, 'utf-8')
except UnicodeDecodeError as e:
# add more information to the error message and re-raise it.
e.reason = '%s in field: %s' % (e, key.full_name)
raise
return value
assert not is_packed
if is_repeated:
tag_bytes = encoder.TagBytes(field_number,
wire_format.WIRETYPE_LENGTH_DELIMITED)
tag_len = len(tag_bytes)
def DecodeRepeatedField(buffer, pos, end, message, field_dict):
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
while 1:
(size, pos) = local_DecodeVarint(buffer, pos)
new_pos = pos + size
if new_pos > end:
raise _DecodeError('Truncated string.')
value.append(_ConvertToUnicode(buffer[pos:new_pos]))
# Predict that the next tag is another copy of the same repeated field.
pos = new_pos + tag_len
if buffer[new_pos:pos] != tag_bytes or new_pos == end:
# Prediction failed. Return.
return new_pos
return DecodeRepeatedField
else:
def DecodeField(buffer, pos, end, message, field_dict):
(size, pos) = local_DecodeVarint(buffer, pos)
new_pos = pos + size
if new_pos > end:
raise _DecodeError('Truncated string.')
if clear_if_default and not size:
field_dict.pop(key, None)
else:
field_dict[key] = _ConvertToUnicode(buffer[pos:new_pos])
return new_pos
return DecodeField
def BytesDecoder(field_number, is_repeated, is_packed, key, new_default,
clear_if_default=False):
"""Returns a decoder for a bytes field."""
local_DecodeVarint = _DecodeVarint
assert not is_packed
if is_repeated:
tag_bytes = encoder.TagBytes(field_number,
wire_format.WIRETYPE_LENGTH_DELIMITED)
tag_len = len(tag_bytes)
def DecodeRepeatedField(buffer, pos, end, message, field_dict):
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
while 1:
(size, pos) = local_DecodeVarint(buffer, pos)
new_pos = pos + size
if new_pos > end:
raise _DecodeError('Truncated string.')
value.append(buffer[pos:new_pos].tobytes())
# Predict that the next tag is another copy of the same repeated field.
pos = new_pos + tag_len
if buffer[new_pos:pos] != tag_bytes or new_pos == end:
# Prediction failed. Return.
return new_pos
return DecodeRepeatedField
else:
def DecodeField(buffer, pos, end, message, field_dict):
(size, pos) = local_DecodeVarint(buffer, pos)
new_pos = pos + size
if new_pos > end:
raise _DecodeError('Truncated string.')
if clear_if_default and not size:
field_dict.pop(key, None)
else:
field_dict[key] = buffer[pos:new_pos].tobytes()
return new_pos
return DecodeField
def GroupDecoder(field_number, is_repeated, is_packed, key, new_default):
"""Returns a decoder for a group field."""
end_tag_bytes = encoder.TagBytes(field_number,
wire_format.WIRETYPE_END_GROUP)
end_tag_len = len(end_tag_bytes)
assert not is_packed
if is_repeated:
tag_bytes = encoder.TagBytes(field_number,
wire_format.WIRETYPE_START_GROUP)
tag_len = len(tag_bytes)
def DecodeRepeatedField(buffer, pos, end, message, field_dict):
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
while 1:
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
# Read sub-message.
pos = value.add()._InternalParse(buffer, pos, end)
# Read end tag.
new_pos = pos+end_tag_len
if buffer[pos:new_pos] != end_tag_bytes or new_pos > end:
raise _DecodeError('Missing group end tag.')
# Predict that the next tag is another copy of the same repeated field.
pos = new_pos + tag_len
if buffer[new_pos:pos] != tag_bytes or new_pos == end:
# Prediction failed. Return.
return new_pos
return DecodeRepeatedField
else:
def DecodeField(buffer, pos, end, message, field_dict):
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
# Read sub-message.
pos = value._InternalParse(buffer, pos, end)
# Read end tag.
new_pos = pos+end_tag_len
if buffer[pos:new_pos] != end_tag_bytes or new_pos > end:
raise _DecodeError('Missing group end tag.')
return new_pos
return DecodeField
def MessageDecoder(field_number, is_repeated, is_packed, key, new_default):
"""Returns a decoder for a message field."""
local_DecodeVarint = _DecodeVarint
assert not is_packed
if is_repeated:
tag_bytes = encoder.TagBytes(field_number,
wire_format.WIRETYPE_LENGTH_DELIMITED)
tag_len = len(tag_bytes)
def DecodeRepeatedField(buffer, pos, end, message, field_dict):
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
while 1:
# Read length.
(size, pos) = local_DecodeVarint(buffer, pos)
new_pos = pos + size
if new_pos > end:
raise _DecodeError('Truncated message.')
# Read sub-message.
if value.add()._InternalParse(buffer, pos, new_pos) != new_pos:
# The only reason _InternalParse would return early is if it
# encountered an end-group tag.
raise _DecodeError('Unexpected end-group tag.')
# Predict that the next tag is another copy of the same repeated field.
pos = new_pos + tag_len
if buffer[new_pos:pos] != tag_bytes or new_pos == end:
# Prediction failed. Return.
return new_pos
return DecodeRepeatedField
else:
def DecodeField(buffer, pos, end, message, field_dict):
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
# Read length.
(size, pos) = local_DecodeVarint(buffer, pos)
new_pos = pos + size
if new_pos > end:
raise _DecodeError('Truncated message.')
# Read sub-message.
if value._InternalParse(buffer, pos, new_pos) != new_pos:
# The only reason _InternalParse would return early is if it encountered
# an end-group tag.
raise _DecodeError('Unexpected end-group tag.')
return new_pos
return DecodeField
# --------------------------------------------------------------------
MESSAGE_SET_ITEM_TAG = encoder.TagBytes(1, wire_format.WIRETYPE_START_GROUP)
def MessageSetItemDecoder(descriptor):
"""Returns a decoder for a MessageSet item.
The parameter is the message Descriptor.
The message set message looks like this:
message MessageSet {
repeated group Item = 1 {
required int32 type_id = 2;
required string message = 3;
}
}
"""
type_id_tag_bytes = encoder.TagBytes(2, wire_format.WIRETYPE_VARINT)
message_tag_bytes = encoder.TagBytes(3, wire_format.WIRETYPE_LENGTH_DELIMITED)
item_end_tag_bytes = encoder.TagBytes(1, wire_format.WIRETYPE_END_GROUP)
local_ReadTag = ReadTag
local_DecodeVarint = _DecodeVarint
local_SkipField = SkipField
def DecodeItem(buffer, pos, end, message, field_dict):
"""Decode serialized message set to its value and new position.
Args:
buffer: memoryview of the serialized bytes.
pos: int, position in the memory view to start at.
end: int, end position of serialized data
message: Message object to store unknown fields in
field_dict: Map[Descriptor, Any] to store decoded values in.
Returns:
int, new position in serialized data.
"""
message_set_item_start = pos
type_id = -1
message_start = -1
message_end = -1
# Technically, type_id and message can appear in any order, so we need
# a little loop here.
while 1:
(tag_bytes, pos) = local_ReadTag(buffer, pos)
if tag_bytes == type_id_tag_bytes:
(type_id, pos) = local_DecodeVarint(buffer, pos)
elif tag_bytes == message_tag_bytes:
(size, message_start) = local_DecodeVarint(buffer, pos)
pos = message_end = message_start + size
elif tag_bytes == item_end_tag_bytes:
break
else:
pos = SkipField(buffer, pos, end, tag_bytes)
if pos == -1:
raise _DecodeError('Missing group end tag.')
if pos > end:
raise _DecodeError('Truncated message.')
if type_id == -1:
raise _DecodeError('MessageSet item missing type_id.')
if message_start == -1:
raise _DecodeError('MessageSet item missing message.')
extension = message.Extensions._FindExtensionByNumber(type_id)
# pylint: disable=protected-access
if extension is not None:
value = field_dict.get(extension)
if value is None:
message_type = extension.message_type
if not hasattr(message_type, '_concrete_class'):
# pylint: disable=protected-access
message._FACTORY.GetPrototype(message_type)
value = field_dict.setdefault(
extension, message_type._concrete_class())
if value._InternalParse(buffer, message_start,message_end) != message_end:
# The only reason _InternalParse would return early is if it encountered
# an end-group tag.
raise _DecodeError('Unexpected end-group tag.')
else:
if not message._unknown_fields:
message._unknown_fields = []
message._unknown_fields.append(
(MESSAGE_SET_ITEM_TAG, buffer[message_set_item_start:pos].tobytes()))
if message._unknown_field_set is None:
message._unknown_field_set = containers.UnknownFieldSet()
message._unknown_field_set._add(
type_id,
wire_format.WIRETYPE_LENGTH_DELIMITED,
buffer[message_start:message_end].tobytes())
# pylint: enable=protected-access
return pos
return DecodeItem
# --------------------------------------------------------------------
def MapDecoder(field_descriptor, new_default, is_message_map):
"""Returns a decoder for a map field."""
key = field_descriptor
tag_bytes = encoder.TagBytes(field_descriptor.number,
wire_format.WIRETYPE_LENGTH_DELIMITED)
tag_len = len(tag_bytes)
local_DecodeVarint = _DecodeVarint
# Can't read _concrete_class yet; might not be initialized.
message_type = field_descriptor.message_type
def DecodeMap(buffer, pos, end, message, field_dict):
submsg = message_type._concrete_class()
value = field_dict.get(key)
if value is None:
value = field_dict.setdefault(key, new_default(message))
while 1:
# Read length.
(size, pos) = local_DecodeVarint(buffer, pos)
new_pos = pos + size
if new_pos > end:
raise _DecodeError('Truncated message.')
# Read sub-message.
submsg.Clear()
if submsg._InternalParse(buffer, pos, new_pos) != new_pos:
# The only reason _InternalParse would return early is if it
# encountered an end-group tag.
raise _DecodeError('Unexpected end-group tag.')
if is_message_map:
value[submsg.key].CopyFrom(submsg.value)
else:
value[submsg.key] = submsg.value
# Predict that the next tag is another copy of the same repeated field.
pos = new_pos + tag_len
if buffer[new_pos:pos] != tag_bytes or new_pos == end:
# Prediction failed. Return.
return new_pos
return DecodeMap
# --------------------------------------------------------------------
# Optimization is not as heavy here because calls to SkipField() are rare,
# except for handling end-group tags.
def _SkipVarint(buffer, pos, end):
"""Skip a varint value. Returns the new position."""
# Previously ord(buffer[pos]) raised IndexError when pos is out of range.
# With this code, ord(b'') raises TypeError. Both are handled in
# python_message.py to generate a 'Truncated message' error.
while ord(buffer[pos:pos+1].tobytes()) & 0x80:
pos += 1
pos += 1
if pos > end:
raise _DecodeError('Truncated message.')
return pos
def _SkipFixed64(buffer, pos, end):
"""Skip a fixed64 value. Returns the new position."""
pos += 8
if pos > end:
raise _DecodeError('Truncated message.')
return pos
def _DecodeFixed64(buffer, pos):
"""Decode a fixed64."""
new_pos = pos + 8
return (struct.unpack('<Q', buffer[pos:new_pos])[0], new_pos)
def _SkipLengthDelimited(buffer, pos, end):
"""Skip a length-delimited value. Returns the new position."""
(size, pos) = _DecodeVarint(buffer, pos)
pos += size
if pos > end:
raise _DecodeError('Truncated message.')
return pos
def _SkipGroup(buffer, pos, end):
"""Skip sub-group. Returns the new position."""
while 1:
(tag_bytes, pos) = ReadTag(buffer, pos)
new_pos = SkipField(buffer, pos, end, tag_bytes)
if new_pos == -1:
return pos
pos = new_pos
def _DecodeUnknownFieldSet(buffer, pos, end_pos=None):
"""Decode UnknownFieldSet. Returns the UnknownFieldSet and new position."""
unknown_field_set = containers.UnknownFieldSet()
while end_pos is None or pos < end_pos:
(tag_bytes, pos) = ReadTag(buffer, pos)
(tag, _) = _DecodeVarint(tag_bytes, 0)
field_number, wire_type = wire_format.UnpackTag(tag)
if wire_type == wire_format.WIRETYPE_END_GROUP:
break
(data, pos) = _DecodeUnknownField(buffer, pos, wire_type)
# pylint: disable=protected-access
unknown_field_set._add(field_number, wire_type, data)
return (unknown_field_set, pos)
def _DecodeUnknownField(buffer, pos, wire_type):
"""Decode a unknown field. Returns the UnknownField and new position."""
if wire_type == wire_format.WIRETYPE_VARINT:
(data, pos) = _DecodeVarint(buffer, pos)
elif wire_type == wire_format.WIRETYPE_FIXED64:
(data, pos) = _DecodeFixed64(buffer, pos)
elif wire_type == wire_format.WIRETYPE_FIXED32:
(data, pos) = _DecodeFixed32(buffer, pos)
elif wire_type == wire_format.WIRETYPE_LENGTH_DELIMITED:
(size, pos) = _DecodeVarint(buffer, pos)
data = buffer[pos:pos+size].tobytes()
pos += size
elif wire_type == wire_format.WIRETYPE_START_GROUP:
(data, pos) = _DecodeUnknownFieldSet(buffer, pos)
elif wire_type == wire_format.WIRETYPE_END_GROUP:
return (0, -1)
else:
raise _DecodeError('Wrong wire type in tag.')
return (data, pos)
def _EndGroup(buffer, pos, end):
"""Skipping an END_GROUP tag returns -1 to tell the parent loop to break."""
return -1
def _SkipFixed32(buffer, pos, end):
"""Skip a fixed32 value. Returns the new position."""
pos += 4
if pos > end:
raise _DecodeError('Truncated message.')
return pos
def _DecodeFixed32(buffer, pos):
"""Decode a fixed32."""
new_pos = pos + 4
return (struct.unpack('<I', buffer[pos:new_pos])[0], new_pos)
def _RaiseInvalidWireType(buffer, pos, end):
"""Skip function for unknown wire types. Raises an exception."""
raise _DecodeError('Tag had invalid wire type.')
def _FieldSkipper():
"""Constructs the SkipField function."""
WIRETYPE_TO_SKIPPER = [
_SkipVarint,
_SkipFixed64,
_SkipLengthDelimited,
_SkipGroup,
_EndGroup,
_SkipFixed32,
_RaiseInvalidWireType,
_RaiseInvalidWireType,
]
wiretype_mask = wire_format.TAG_TYPE_MASK
def SkipField(buffer, pos, end, tag_bytes):
"""Skips a field with the specified tag.
|pos| should point to the byte immediately after the tag.
Returns:
The new position (after the tag value), or -1 if the tag is an end-group
tag (in which case the calling loop should break).
"""
# The wire type is always in the first byte since varints are little-endian.
wire_type = ord(tag_bytes[0:1]) & wiretype_mask
return WIRETYPE_TO_SKIPPER[wire_type](buffer, pos, end)
return SkipField
SkipField = _FieldSkipper()
|