Class MessageBrokerListener

Namespace

LfrlAnvil.MessageBroker.Client

Assembly

LfrlAnvil.MessageBroker.Client.dll

Represents a message broker listener, which allows the client to react to messages published to the related channel.

public sealed class MessageBrokerListener

Inheritance

object

MessageBrokerListener

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

Properties

AreAcksEnabled

Specifies whether the Client is expected to send ACK or negative ACK to the server in order to confirm message notification.

public bool AreAcksEnabled { get; }

Property Value

bool

Callback

Callback invoked when this listener receives a message from the server.

public MessageBrokerListenerCallback Callback { get; }

Property Value

MessageBrokerListenerCallback

ChannelId

Unique id of the channel to which this listener is related.

public int ChannelId { get; }

Property Value

int

ChannelName

Unique name of the channel to which this listener is related.

public string ChannelName { get; }

Property Value

string

Client

MessageBrokerClient instance that owns this listener.

public MessageBrokerClient Client { get; }

Property Value

MessageBrokerClient

DeadLetterCapacityHint

Specifies how many messages will be stored at most by the dead letter.

public int DeadLetterCapacityHint { get; }

Property Value

int

Remarks

This is a min value. Actual value is dependant on all listeners attached to the queue and the state of the queue's dead letter.

FilterExpression

Specifies server-side message filter expression.

public string? FilterExpression { get; }

Property Value

string

IsEphemeral

Specifies whether the listener is ephemeral.

public bool IsEphemeral { get; }

Property Value

bool

Remarks

Ephemeral listeners will be removed by the server when client disconnects.

MaxRedeliveries

Specifies how many times the server will attempt to automatically send a message notification redelivery when the Client fails to respond with either an ACK or a negative ACK in time (see MinAckTimeout), before giving up.

public int MaxRedeliveries { get; }

Property Value

int

Remarks

Redelivery are disabled when value is equal 0.

MaxRetries

Specifies how many times the server will attempt to automatically send a message notification retry when the Client responds with a negative ACK, before giving up.

public int MaxRetries { get; }

Property Value

int

Remarks

Retries are disabled when value is equal 0.

MinAckTimeout

Specifies the minimum amount of time that the server will wait for the Client to send either an ACK or a negative ACK before attempting a message notification redelivery. Actual ACK timeout may be different due to the state of the queue and other listeners bound to it.

public Duration MinAckTimeout { get; }

Property Value

Duration

MinDeadLetterRetention

Specifies retention period for messages stored in the dead letter.

public Duration MinDeadLetterRetention { get; }

Property Value

Duration

Remarks

This is a min value. Actual value is dependant on all listeners attached to the queue and the state of the queue's dead letter.

PrefetchHint

Specifies how many messages intended for this listener can be sent by the server to the Client at the same time.

public short PrefetchHint { get; }

Property Value

short

Remarks

This is a max potential value. Actual value is dependant on all listeners attached to the queue and all of its currently pending messages.

QueueId

Unique id of the queue to which this listener is related.

public int QueueId { get; }

Property Value

int

QueueName

Unique name of the queue to which this listener is related.

public string QueueName { get; }

Property Value

string

RetryDelay

Specifies the delay between the server successfully processing negative ACK sent by the Client and the server sending a message notification retry.

public Duration RetryDelay { get; }

Property Value

Duration

State

Current listener's state.

public MessageBrokerListenerState State { get; }

Property Value

MessageBrokerListenerState

Remarks

See MessageBrokerListenerState for more information.

Methods

SendMessageAckAsync(int, int, ulong, int, int)

Attempts to send a message notification ACK.

public ValueTask<Result<bool>> SendMessageAckAsync(int ackId, int streamId, ulong messageId, int retry, int redelivery)

Parameters

ackId int

Id of the pending ACK associated with the message.

streamId int

Unique id of the server-side stream that handled the message.

messageId ulong

Unique message id.

retry int

Retry attempt of the message.

redelivery int

Redelivery number of the message.

Returns

ValueTask<Result<bool>>

A task that represents the operation, which returns a Result<T> instance, with underlying bool result. If the result is equal to true, then ACK sending was successful, otherwise the listener was no longer bound to the channel.

Remarks

Unexpected errors encountered during ACK sending attempt will cause the client to be automatically disposed. Returned Result<T> will only be valid when either the client has successfully sent the ACK to the server, or the listener is already locally ubound from the channel, which will cancel the request to the server.

Exceptions

ArgumentOutOfRangeException

When ackId is less than or equal to 0 or when streamId is less than or equal to 0 or when retry is less than 0 or greater than the listener's MaxRetries or when redelivery is less than 0 or greater than the listener's MaxRedeliveries.

MessageBrokerClientDisposedException

When client has already been disposed.

MessageBrokerClientMessageException

When ACKs are not enabled for this listener.

SendNegativeMessageAckAsync(int, int, ulong, int, int, MessageBrokerNegativeAck)

Attempts to send a negative message notification ACK.

public ValueTask<Result<bool>> SendNegativeMessageAckAsync(int ackId, int streamId, ulong messageId, int retry, int redelivery, MessageBrokerNegativeAck nack = default)

Parameters

ackId int

Id of the pending ACK associated with the message.

streamId int

Unique id of the server-side stream that handled the message.

messageId ulong

Unique message id.

retry int

Retry attempt of the message.

redelivery int

Redelivery attempt of the message.

nack MessageBrokerNegativeAck

Optional MessageBrokerNegativeAck instance that allows to modify the ACK. Equal to Default by default.

Returns

ValueTask<Result<bool>>

A task that represents the operation, which returns a Result<T> instance, with underlying bool result. If the result is equal to true, then ACK sending was successful, otherwise the listener was no longer bound to the channel.

Remarks

Unexpected errors encountered during ACK sending attempt will cause the client to be automatically disposed. Returned Result<T> will only be valid when either the client has successfully sent the ACK to the server, or the listener is already locally ubound from the channel, which will cancel the request to the server.

Exceptions

ArgumentOutOfRangeException

When ackId is less than or equal to 0 or when streamId is less than or equal to 0 or when retry is less than 0 or greater than the listener's MaxRetries or when redelivery is less than 0 or greater than the listener's MaxRedeliveries.

MessageBrokerClientDisposedException

When client has already been disposed.

MessageBrokerClientMessageException

When ACKs are not enabled for this listener.

ToString()

Returns a string representation of this MessageBrokerListener instance.

[Pure]
public override string ToString()

Returns

string

String representation.

UnbindAsync()

Attempts to unbind this listener from the channel.

public ValueTask<Result<MessageBrokerUnbindListenerResult>> UnbindAsync()

Returns

ValueTask<Result<MessageBrokerUnbindListenerResult>>

A task that represents the operation, which returns a Result<T> instance, with underlying MessageBrokerUnbindListenerResult instance.

Remarks

This operation will cause all pending messages for this listener to be discarded. Unexpected errors encountered during listener unbinding will cause the client to be automatically disposed. Returned Result<T> will only be valid when either the listener has been successfully unbound from the channel on the server side, or the listener is already locally unbound from the channel, which will cancel the request to the server.

Exceptions

MessageBrokerClientDisposedException

When client has already been disposed.