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
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
def StringDecoder(field_number, is_repeated, is_packed, key, new_default):
"""Returns a decoder for a string field."""
local_DecodeVarint = _DecodeVarint
local_unicode = unicode
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(local_unicode(buffer[pos:new_pos], 'utf-8'))
# 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] = local_unicode(buffer[pos:new_pos], 'utf-8')
return new_pos
return DecodeField
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
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;
}
}
"""
def AddDecoder(wiretype, is_packed):
tag_bytes = encoder.TagBytes(field_descriptor.number, wiretype)
cls._decoders_by_tag[tag_bytes] = (
type_checkers.TYPE_TO_DECODER[field_descriptor.type](
field_descriptor.number, is_repeated, is_packed,
field_descriptor, field_descriptor._default_constructor))