blob: cc2562bf947d1b6c299c1c8ff826f398c81d7eb6 [file] [log] [blame]
/*
* Licensed 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.
*/
namespace DotPulsar
{
using Abstractions;
using HashDepot;
using System;
/// <summary>
/// The single partition messages router.
/// If a key is provided, the producer will hash the key and publish the message to a particular partition.
/// If a key is not provided, the producer will randomly pick one single partition and publish all messages to that partition.
/// </summary>
public sealed class SinglePartitionRouter : IMessageRouter
{
private int _partitionIndex;
/// <summary>
/// Initializes a new instance of the single partition router that will randomly select a partition
/// </summary>
public SinglePartitionRouter()
{
_partitionIndex = -1;
}
/// <summary>
/// Initializes a new instance of the single partition router that will publish all messages to the given partition
/// </summary>
public SinglePartitionRouter(int partitionIndex)
{
_partitionIndex = partitionIndex;
}
/// <summary>
/// Choose a partition in single partition routing mode
/// </summary>
public int ChoosePartition(MessageMetadata messageMetadata, int numberOfPartitions)
{
var keyBytes = messageMetadata.KeyBytes;
if (keyBytes is not null)
return (int) MurmurHash3.Hash32(keyBytes, 0) % numberOfPartitions;
if (_partitionIndex == -1)
_partitionIndex = new Random().Next(0, numberOfPartitions);
return _partitionIndex;
}
}
}