Renamed google.protobuf to protobuf26

third_party/google/protobuf/internal/decoder.py

Index: third_party/google/protobuf/internal/decoder.py
diff --git a/third_party/google/protobuf/internal/decoder.py b/third_party/google/protobuf/internal/decoder.py
deleted file mode 100644
index 651ee0d4ad469ccf92044242266d188c00d0c6ef..0000000000000000000000000000000000000000
--- a/third_party/google/protobuf/internal/decoder.py
+++ /dev/null
@@ -1,831 +0,0 @@
-# Protocol Buffers - Google's data interchange format
-# Copyright 2008 Google Inc.  All rights reserved.
-# http://code.google.com/p/protobuf/
-#
-# 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.
-
-#PY25 compatible for GAE.
-#
-# Copyright 2009 Google Inc. All Rights Reserved.
-
-"""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__ = 'kenton@google.com (Kenton Varda)'
-
-import struct
-import sys  ##PY25
-_PY2 = sys.version_info[0] < 3  ##PY25
-from google.protobuf.internal import encoder
-from google.protobuf.internal import wire_format
-from google.protobuf import message
-
-
-# This will overflow and thus become IEEE-754 "infinity".  We would use
-# "float('inf')" but it doesn't work on Windows pre-Python-2.6.
-_POS_INF = 1e10000
-_NEG_INF = -_POS_INF
-_NAN = _POS_INF * 0
-
-
-# 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.
-  """
-
-  local_ord = ord
-  py2 = _PY2  ##PY25
-##!PY25  py2 = str is bytes
-  def DecodeVarint(buffer, pos):
-    result = 0
-    shift = 0
-    while 1:
-      b = local_ord(buffer[pos]) if py2 else 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(mask, result_type):
-  """Like _VarintDecoder() but decodes signed values."""
-
-  local_ord = ord
-  py2 = _PY2  ##PY25
-##!PY25  py2 = str is bytes
-  def DecodeVarint(buffer, pos):
-    result = 0
-    shift = 0
-    while 1:
-      b = local_ord(buffer[pos]) if py2 else buffer[pos]
-      result |= ((b & 0x7f) << shift)
-      pos += 1
-      if not (b & 0x80):
-        if result > 0x7fffffffffffffff:
-          result -= (1 << 64)
-          result |= ~mask
-        else:
-          result &= mask
-        result = result_type(result)
-        return (result, pos)
-      shift += 7
-      if shift >= 64:
-        raise _DecodeError('Too many bytes when decoding varint.')
-  return DecodeVarint
-
-# We force 32-bit values to int and 64-bit values to long to make
-# alternate implementations where the distinction is more significant
-# (e.g. the C++ implementation) simpler.
-
-_DecodeVarint = _VarintDecoder((1 << 64) - 1, long)
-_DecodeSignedVarint = _SignedVarintDecoder((1 << 64) - 1, long)
-
-# Use these versions for values which must be limited to 32 bits.
-_DecodeVarint32 = _VarintDecoder((1 << 32) - 1, int)
-_DecodeSignedVarint32 = _SignedVarintDecoder((1 << 32) - 1, int)
-
-
-def ReadTag(buffer, pos):
-  """Read a tag from the buffer, 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.
-  """
-
-  py2 = _PY2  ##PY25
-##!PY25  py2 = str is bytes
-  start = pos
-  while (ord(buffer[pos]) if py2 else buffer[pos]) & 0x80:
-    pos += 1
-  pos += 1
-  return (buffer[start:pos], 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):
-    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):
-        (field_dict[key], pos) = decode_value(buffer, pos)
-        if pos > end:
-          del field_dict[key]  # Discard corrupt value.
-          raise _DecodeError('Truncated message.')
-        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
-  b = (lambda x:x) if _PY2 else lambda x:x.encode('latin1')  ##PY25
-
-  def InnerDecode(buffer, pos):
-    # 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]
-
-    # 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'))  ##PY25
-##!PY25    if ((float_bytes[3:4] in b'\x7F\xFF')
-        and (float_bytes[2:3] >= b('\x80'))):  ##PY25
-##!PY25        and (float_bytes[2:3] >= b'\x80')):
-      # If at least one significand bit is set...
-      if float_bytes[0:3] != b('\x00\x00\x80'):  ##PY25
-##!PY25      if float_bytes[0:3] != b'\x00\x00\x80':
-        return (_NAN, new_pos)
-      # If sign bit is set...
-      if float_bytes[3:4] == b('\xFF'):  ##PY25
-##!PY25      if float_bytes[3:4] == b'\xFF':
-        return (_NEG_INF, new_pos)
-      return (_POS_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
-  b = (lambda x:x) if _PY2 else lambda x:x.encode('latin1')  ##PY25
-
-  def InnerDecode(buffer, pos):
-    # 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]
-
-    # 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.
-##!PY25    if ((double_bytes[7:8] in b'\x7F\xFF')
-##!PY25        and (double_bytes[6:7] >= b'\xF0')
-##!PY25        and (double_bytes[0:7] != b'\x00\x00\x00\x00\x00\x00\xF0')):
-    if ((double_bytes[7:8] in b('\x7F\xFF'))  ##PY25
-        and (double_bytes[6:7] >= b('\xF0'))  ##PY25
-        and (double_bytes[0:7] != b('\x00\x00\x00\x00\x00\x00\xF0'))):  ##PY25
-      return (_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):
-  enum_type = key.enum_type
-  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:
-        value_start_pos = pos
-        (element, pos) = _DecodeSignedVarint32(buffer, pos)
-        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]))
-      if pos > endpoint:
-        if element in enum_type.values_by_number:
-          del value[-1]   # Discard corrupt value.
-        else:
-          del message._unknown_fields[-1]
-        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):
-      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)
-        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]))
-        # 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):
-      value_start_pos = pos
-      (enum_value, pos) = _DecodeSignedVarint32(buffer, pos)
-      if pos > end:
-        raise _DecodeError('Truncated message.')
-      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]))
-      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):
-  """Returns a decoder for a string field."""
-
-  local_DecodeVarint = _DecodeVarint
-  local_unicode = unicode
-
-  def _ConvertToUnicode(byte_str):
-    try:
-      return local_unicode(byte_str, 'utf-8')
-    except UnicodeDecodeError, e:
-      # add more information to the error message and re-raise it.
-      e.reason = '%s in field: %s' % (e, key.full_name)
-      raise
-
-  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.')
-      field_dict[key] = _ConvertToUnicode(buffer[pos:new_pos])
-      return new_pos
-    return DecodeField
-
-
-def BytesDecoder(field_number, is_repeated, is_packed, key, new_default):
-  """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])
-        # 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.')
-      field_dict[key] = buffer[pos:new_pos]
-      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:
-        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.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(extensions_by_number):
-  """Returns a decoder for a MessageSet item.
-
-  The parameter is the _extensions_by_number map for the message class.
-
-  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):
-    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 = extensions_by_number.get(type_id)
-    if extension is not None:
-      value = field_dict.get(extension)
-      if value is None:
-        value = field_dict.setdefault(
-            extension, 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]))
-
-    return pos
-
-  return DecodeItem
-
-# --------------------------------------------------------------------
-# 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]) & 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 _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 _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 _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()