| // 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. |
| |
| package pulsar |
| |
| import "sync" |
| |
| func NewSinglePartitionRouter() func(*ProducerMessage, TopicMetadata) int { |
| var ( |
| singlePartition *int |
| once sync.Once |
| ) |
| return func(message *ProducerMessage, metadata TopicMetadata) int { |
| numPartitions := metadata.NumPartitions() |
| if len(message.Key) != 0 { |
| // When a key is specified, use the hash of that key |
| return int(getHashingFunction(JavaStringHash)(message.Key) % numPartitions) |
| } |
| once.Do(func() { |
| partition := r.R.Intn(int(numPartitions)) |
| singlePartition = &partition |
| }) |
| |
| return *singlePartition |
| |
| } |
| |
| } |