private async Task EnqueueMessageWithCapacity(MessageArgs <TMessage> msg)
{
if (m_messageCollection.TryAdd(msg) || FullBehaviour == QueueFullBehaviour.AbandonNew)
{
return;
}
if (FullBehaviour == QueueFullBehaviour.BlockPublisher)
{
await m_messageCollection.AddAsync(msg);
return;
}
#if DEBUG
System.Diagnostics.Contracts.Contract.Assert(FullBehaviour == QueueFullBehaviour.RemoveOldest,
"FullBehaviour should be QueueFullBehaviour.RemoveOldest");
#endif
// 尝试获取空位, 不成功时进入循环体
while (!(m_messageCollection.TryAdd(msg)))
{
// 获取空位失败, 尝试移除队首元素
m_messageCollection.TryTake(out _);
}
}
/// <summary>
/// 向使用指定路由键<paramref name="key"/>注册的订阅者发布消息
/// </summary>
/// <param name="key">路由key</param>
/// <param name="message">消息对象</param>
/// <exception cref="ArgumentNullException"><paramref name="message"/>为空</exception>
public async Task <MessagePublishResult> PublishMessageAsync(string key, TMessage message)
{
if (message == null)
{
throw new ArgumentNullException(nameof(message));
}
if (key == null)
{
throw new ArgumentNullException(nameof(key));
}
if (!m_subscribers.TryGetValue(key, out var handlers) ||
handlers.Count == 0)
{
return(MessagePublishResult.None);
}
var result = new MessagePublishResult
{
ReceiverCount = (uint)handlers.Count
};
var bindings = new[] { key };
try
{
var subscribers = handlers
.Select(func =>
{
var msgArgs = new MessageArgs <TMessage>(
this, key,
new ReadOnlyCollection <string>(bindings),
message);
return(Task.Run(() => func(msgArgs)));
})
.ToArray();
await Task.WhenAll(subscribers);
}
catch (Exception e)
{
result.Exception = e;
}
return(result);
}
/// <summary>
/// 向使用指定路由键<paramref name="key"/>注册的订阅者发布消息
/// </summary>
/// <param name="key">路由key</param>
/// <param name="message">消息对象</param>
/// <exception cref="ArgumentNullException"><paramref name="message"/>为空</exception>
public async Task <MessagePublishResult> PublishMessageAsync(string key, TMessage message)
{
if (message == null)
{
throw new ArgumentNullException(nameof(message));
}
if (key == null)
{
throw new ArgumentNullException(nameof(key));
}
var handlers = m_handlers
.ToArray();
if (handlers.Length == 0)
{
return(MessagePublishResult.None);
}
var result = new MessagePublishResult();
try
{
var subscribers = handlers
.Where(pair => pair.Value.Count > 0)
.Select(pair =>
{
var msgArgs = new MessageArgs <TMessage>(
this, key,
pair.Value,
message);
return(Task.Run(() => pair.Key(msgArgs)));
})
.ToArray();
result.ReceiverCount = (uint)subscribers.Length;
await Task.WhenAll(subscribers);
}
catch (Exception e)
{
result.Exception = e;
}
return(result);
}
/// <summary>
/// 尝试获取队列中的消息, 如果队列中没有消息, 则立即返回false
/// </summary>
/// <param name="message"></param>
/// <returns></returns>
public bool TryTakeMessage(out MessageArgs <TMessage> message)
{
return(m_messageCollection.TryTake(out message));
}