DigitalFactory/Admin.NET/Admin.NET.Core/EventBus/RabbitMQEventSourceStore.cs

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2024-03-18 01:36:19 +00:00
// 大名科技(天津)有限公司版权所有 电话18020030720 QQ515096995
//
// 此源代码遵循位于源代码树根目录中的 LICENSE 文件的许可证
using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using System.Threading.Channels;
namespace Admin.NET.Core;
/// <summary>
/// RabbitMQ自定义事件源存储器
/// </summary>
public class RabbitMQEventSourceStore : IEventSourceStorer
{
/// <summary>
/// 内存通道事件源存储器
/// </summary>
private readonly Channel<IEventSource> _channel;
/// <summary>
/// 通道对象
/// </summary>
private readonly IModel _model;
/// <summary>
/// 连接对象
/// </summary>
private readonly IConnection _connection;
/// <summary>
/// 路由键
/// </summary>
private readonly string _routeKey;
/// <summary>
/// 构造函数
/// </summary>
/// <param name="factory">连接工厂</param>
/// <param name="routeKey">路由键</param>
/// <param name="capacity">存储器最多能够处理多少消息,超过该容量进入等待写入</param>
public RabbitMQEventSourceStore(ConnectionFactory factory, string routeKey, int capacity)
{
// 配置通道,设置超出默认容量后进入等待
var boundedChannelOptions = new BoundedChannelOptions(capacity)
{
FullMode = BoundedChannelFullMode.Wait
};
// 创建有限容量通道
_channel = Channel.CreateBounded<IEventSource>(boundedChannelOptions);
// 创建连接
_connection = factory.CreateConnection();
_routeKey = routeKey;
// 创建通道
_model = _connection.CreateModel();
// 声明路由队列
_model.QueueDeclare(routeKey, false, false, false, null);
// 创建消息订阅者
var consumer = new EventingBasicConsumer(_model);
// 订阅消息并写入内存 Channel
consumer.Received += (ch, ea) =>
{
// 读取原始消息
var stringEventSource = Encoding.UTF8.GetString(ea.Body.ToArray());
// 转换为 IEventSource如果自定义了 EventSource注意属性是可读可写
var eventSource = JSON.Deserialize<ChannelEventSource>(stringEventSource);
// 写入内存管道存储器
_channel.Writer.WriteAsync(eventSource);
// 确认该消息已被消费
_model.BasicAck(ea.DeliveryTag, false);
};
// 启动消费者且设置为手动应答消息
_model.BasicConsume(routeKey, false, consumer);
}
/// <summary>
/// 将事件源写入存储器
/// </summary>
/// <param name="eventSource">事件源对象</param>
/// <param name="cancellationToken">取消任务 Token</param>
/// <returns><see cref="ValueTask"/></returns>
public async ValueTask WriteAsync(IEventSource eventSource, CancellationToken cancellationToken)
{
if (eventSource == default)
throw new ArgumentNullException(nameof(eventSource));
// 判断是否是 ChannelEventSource 或自定义的 EventSource
if (eventSource is ChannelEventSource source)
{
// 序列化及发布
var data = Encoding.UTF8.GetBytes(JSON.Serialize(source));
_model.BasicPublish("", _routeKey, null, data);
}
else
{
// 处理动态订阅
await _channel.Writer.WriteAsync(eventSource, cancellationToken);
}
}
/// <summary>
/// 从存储器中读取一条事件源
/// </summary>
/// <param name="cancellationToken">取消任务 Token</param>
/// <returns>事件源对象</returns>
public async ValueTask<IEventSource> ReadAsync(CancellationToken cancellationToken)
{
var eventSource = await _channel.Reader.ReadAsync(cancellationToken);
return eventSource;
}
/// <summary>
/// 释放非托管资源
/// </summary>
public void Dispose()
{
_model.Dispose();
_connection.Dispose();
}
}