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