Source code for pyflink.common.serializer

################################################################################
#  Licensed to the Apache Software Foundation (ASF) under one
#  or more contributor license agreements.  See the NOTICE file
#  distributed with this work for additional information
#  regarding copyright ownership.  The ASF licenses this file
#  to you under the Apache License, Version 2.0 (the
#  "License"); you may not use this file except in compliance
#  with the License.  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
# limitations under the License.
################################################################################

from abc import abstractmethod, ABC
from io import BytesIO
from typing import TypeVar, Generic

T = TypeVar('T')

__all__ = ['TypeSerializer']


[docs]class TypeSerializer(ABC, Generic[T]): """ This interface describes the methods that are required for a data type to be handled by the Flink runtime. Specifically, this interface contains the serialization and deserialization methods. """ def __eq__(self, other): return isinstance(other, self.__class__) and self.__dict__ == other.__dict__ def __ne__(self, other): return not self.__eq__(other) def __repr__(self): return "%s()" % self.__class__.__name__ def __hash__(self): return hash(str(self))
[docs] @abstractmethod def serialize(self, element: T, stream: BytesIO) -> None: """ Serializes an element to the output stream. """ pass
[docs] @abstractmethod def deserialize(self, stream: BytesIO) -> T: """ Returns a deserialized element from the input stream. """ pass
def _get_coder(self): serialize_func = self.serialize deserialize_func = self.deserialize class CoderAdapter(object): def get_impl(self): return CoderAdapterIml() class CoderAdapterIml(object): def encode_nested(self, element): bytes_io = BytesIO() serialize_func(element, bytes_io) return bytes_io.getvalue() def decode_nested(self, bytes_data): bytes_io = BytesIO(bytes_data) return deserialize_func(bytes_io) return CoderAdapter()
void = b'' class VoidNamespaceSerializer(TypeSerializer[bytes]): def serialize(self, element: bytes, stream: BytesIO) -> None: pass def deserialize(self, stream: BytesIO) -> bytes: return void