Class ReceiverLink

The ReceiverLink class represents a link that accepts incoming messages.

Inheritance

System.Object

AmqpObject

Link

ReceiverLink

Implements

IReceiverLink

ILink

IAmqpObject

Inherited Members

Link.DetachAsync(Error)

Link.Name

Link.Handle

Link.Session

Link.LinkState

Link.Detach(Error)

AmqpObject.Closed

AmqpObject.Error

AmqpObject.IsClosed

AmqpObject.AddClosedCallback(ClosedCallback)

AmqpObject.Close()

AmqpObject.Close(TimeSpan, Error)

AmqpObject.CloseAsync()

AmqpObject.CloseAsync(TimeSpan, Error)

System.Object.ToString()

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

Namespace: Amqp

Assembly: Amqp.Net.dll

Syntax

public class ReceiverLink : Link, IReceiverLink, ILink, IAmqpObject

Constructors

ReceiverLink(Session, String, Attach, OnAttached)

Initializes a receiver link.

Declaration

public ReceiverLink(Session session, string name, Attach attach, OnAttached onAttached)

Parameters

Type	Name	Description
Session	session	The session within which to create the link.
System.String	name	The link name.
Attach	attach	The attach frame to send for this link.
OnAttached	onAttached	The callback to invoke when an attach is received from peer.

ReceiverLink(Session, String, Source, OnAttached)

Initializes a receiver link.

Declaration

public ReceiverLink(Session session, string name, Source source, OnAttached onAttached)

Parameters

Type	Name	Description
Session	session	The session within which to create the link.
System.String	name	The link name.
Source	source	The source on attach that specifies the message source.
OnAttached	onAttached	The callback to invoke when an attach is received from peer.

ReceiverLink(Session, String, String)

Initializes a receiver link.

Declaration

public ReceiverLink(Session session, string name, string address)

Parameters

Type	Name	Description
Session	session	The session within which to create the link.
System.String	name	The link name.
System.String	address	The node address.

Methods

Accept(Message)

Accepts a message. It sends an accepted outcome to the peer.

Declaration

public void Accept(Message message)

Parameters

Type	Name	Description
Message	message	The message to accept.

Complete(Message, DeliveryState)

Completes a received message. It settles the delivery and sends a disposition with the delivery state to the remote peer.

Declaration

public void Complete(Message message, DeliveryState deliveryState)

Parameters

Type	Name	Description
Message	message	The message to complete.
DeliveryState	deliveryState	An Outcome or a TransactionalState.

Remarks

This method is not transaction aware. It should be used to bypass transaction context look up when transactions are not used at all, or to manage AMQP transactions directly by providing a TransactionalState to deliveryState.

Modify(Message, Boolean, Boolean, Fields)

Modifies a message. It sends a modified outcome to the peer.

Declaration

public void Modify(Message message, bool deliveryFailed, bool undeliverableHere = false, Fields messageAnnotations = null)

Parameters

Type	Name	Description
Message	message	The message to modify.
System.Boolean	deliveryFailed	If set, the message's delivery-count is incremented.
System.Boolean	undeliverableHere	Indicates if the message should not be redelivered to this endpoint.
Fields	messageAnnotations	Annotations to be combined with the current message annotations.

OnAbort(Error)

Aborts the receiver link.

Declaration

protected override void OnAbort(Error error)

Parameters

Type	Name	Description
Error	error	The error for the abort.

Overrides

Link.OnAbort(Error)

OnClose(Error)

Closes the receiver link.

Declaration

protected override bool OnClose(Error error)

Parameters

Type	Name	Description
Error	error	The error for the closure.

Returns

Type	Description
System.Boolean

Overrides

Link.OnClose(Error)

Receive()

Receives a message. The call is blocked until a message is available or after a default wait time.

Declaration

public Message Receive()

Returns

Type	Description
Message	A Message object if available; otherwise a null value.

Receive(TimeSpan)

Receives a message. The call is blocked until a message is available or the timeout duration expires.

Declaration

public Message Receive(TimeSpan timeout)

Parameters

Type	Name	Description
System.TimeSpan	timeout	The time to wait for a message.

Returns

Type	Description
Message	A Message object if available; otherwise a null value.

Remarks

Use TimeSpan.MaxValue or Timeout.InfiniteTimeSpan to wait infinitely. If TimeSpan.Zero is supplied, the call returns immediately.

ReceiveAsync()

Receives a message asynchronously.

Declaration

public Task<Message> ReceiveAsync()

Returns

Type	Description
System.Threading.Tasks.Task<Message>	A Task for the asynchronous receive operation. The result is a Message object if available within a default timeout; otherwise a null value.

ReceiveAsync(TimeSpan)

Receives a message asynchronously.

Declaration

public Task<Message> ReceiveAsync(TimeSpan timeout)

Parameters

Type	Name	Description
System.TimeSpan	timeout	The time to wait for a message.

Returns

Type	Description
System.Threading.Tasks.Task<Message>	A Task for the asynchronous receive operation. The result is a Message object if available within the specified timeout; otherwise a null value.

Remarks

Use TimeSpan.MaxValue or Timeout.InfiniteTimeSpan to wait infinitely. If TimeSpan.Zero is supplied, the task completes immediately.

Reject(Message, Error)

Rejects a message. It sends a rejected outcome to the peer.

Declaration

public void Reject(Message message, Error error = null)

Parameters

Type	Name	Description
Message	message	The message to reject.
Error	error	The error, if any, for the rejection.

Release(Message)

Releases a message. It sends a released outcome to the peer.

Declaration

public void Release(Message message)

Parameters

Type	Name	Description
Message	message	The message to release.

SetCredit(Int32, CreditMode, Int32)

Sets a credit on the link and the credit management mode.

Declaration

public void SetCredit(int credit, CreditMode creditMode, int flowThreshold = -1)

Parameters

Type	Name	Description
System.Int32	credit	The new link credit.
CreditMode	creditMode	The credit management mode.
System.Int32	flowThreshold	If credit mode is Auto, it is the threshold of restored credits that trigers a flow; ignored otherwise.

Remarks

The receiver link has a default link credit (200). If the default value is not optimal, application should call this method once after the receiver link is created. In Auto credit mode, the credit parameter defines the total credits of the link which is also the total number messages the remote peer can send. The link keeps track of acknowledged messages and triggers a flow when a threshold is reached. The default threshold is half of Amqp.ReceiverLink.credit. Application acknowledges a message by calling Accept(Message), Reject(Message, Error), Release(Message) or Modify(Message, Boolean, Boolean, Fields) method. In Manual credit mode, the credit parameter defines the extra credits of the link which is the additional messages the remote peer can send. Please note the following.

1. In Auto mode, calling this method multiple times with different credits is allowed but not recommended. Application may do this if, for example, it needs to control local queue depth based on resource usage. If credit is reduced, the link maintains a buffer so incoming messages are still allowed.
2. The creditMode should not be changed after it is initially set.
3. To stop a receiver link, set credit to 0. However application should expect in-flight messages to come as a result of the previous credit. It is recommended to use the Drain mode if the application wishes to stop the messages after a given credit is used.
4. In drain credit mode, if a drain cycle is still in progress, the call simply returns without sending a flow. Application is expected to keep calling Receive() in a loop until all messages are received or a null message is returned.
5. In manual credit mode, application is responsible for keeping track of processed messages and issue more credits when certain conditions are met.

SetCredit(Int32, Boolean)

Sets a credit on the link. The credit controls how many messages the peer can send.

Declaration

public void SetCredit(int credit, bool autoRestore = true)

Parameters

Type	Name	Description
System.Int32	credit	The new link credit.
System.Boolean	autoRestore	If true, this method is the same as SetCredit(credit, CreditMode.Auto); if false, it is the same as SetCredit(credit, CreditMode.Manual).

Start(Int32, MessageCallback)

Starts the message pump.

Declaration

public void Start(int credit, MessageCallback onMessage = null)

Parameters

Type	Name	Description
System.Int32	credit	The link credit to issue. See SetCredit(Int32, Boolean) for more details.
MessageCallback	onMessage	If specified, the callback to invoke when messages are received. If not specified, call Receive method to get the messages.

Implements

IReceiverLink

ILink

IAmqpObject