codekingpro/portable-devtools

1# Copyright 2015 gRPC authors.
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#     http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14"""Interfaces related to streams of values or objects."""
15
16import abc
17
18
19class Consumer(abc.ABC):
20    """Interface for consumers of finite streams of values or objects."""
21
22    @abc.abstractmethod
23    def consume(self, value):
24        """Accepts a value.
25
26        Args:
27          value: Any value accepted by this Consumer.
28        """
29        raise NotImplementedError()
30
31    @abc.abstractmethod
32    def terminate(self):
33        """Indicates to this Consumer that no more values will be supplied."""
34        raise NotImplementedError()
35
36    @abc.abstractmethod
37    def consume_and_terminate(self, value):
38        """Supplies a value and signals that no more values will be supplied.
39
40        Args:
41          value: Any value accepted by this Consumer.
42        """
43        raise NotImplementedError()
44