| # 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. |
| |
| |
| class RoundRobin: |
| """ |
| Round-robin generator for use with `Client.connect()`. Cycles a node |
| list until a maximum number of reconnects is reached (if set). |
| """ |
| |
| def __init__(self, nodes: list, max_reconnects: int=None): |
| """ |
| :param nodes: list of two-tuples of (host, port) format, |
| :param max_reconnects: (optional) maximum number of reconnect attempts. |
| defaults to None (cycle nodes infinitely). |
| """ |
| self.nodes = nodes |
| self.max_reconnects = max_reconnects |
| self.node_index = 0 |
| self.reconnects = 0 |
| |
| def __iter__(self) -> 'RoundRobin': |
| return self |
| |
| def __next__(self) -> tuple: |
| if self.max_reconnects is not None: |
| if self.reconnects >= self.max_reconnects: |
| raise StopIteration |
| else: |
| self.reconnects += 1 |
| |
| if self.node_index >= len(self.nodes): |
| self.node_index = 0 |
| node = self.nodes[self.node_index] |
| self.node_index += 1 |
| return node |
