Package org.apache.qpid.proton.engine

Interface Receiver

All Superinterfaces:

Endpoint, Extendable, Link

All Known Implementing Classes:

ReceiverImpl

public interface Receiver
extends Link

Receiver

Method Summary

Modifier and Type	Method	Description
boolean	advance()	Attempts to advance the current delivery.
void	drain(int credit)
boolean	draining()
void	flow(int credits)	Adds the specified number of credits.
ReadableBuffer	recv()	Receive message data for the current delivery returning the data in a Readable buffer.
int	recv(byte[] bytes, int offset, int size)	Receive message data for the current delivery.
int	recv(WritableBuffer buffer)	Receive message data for the current delivery.
void	setDrain(boolean drain)

Methods inherited from interface org.apache.qpid.proton.engine.Endpoint

close, free, getCondition, getContext, getLocalState, getRemoteCondition, getRemoteState, open, setCondition, setContext

Methods inherited from interface org.apache.qpid.proton.engine.Extendable

attachments

Methods inherited from interface org.apache.qpid.proton.engine.Link

current, delivery, delivery, detach, detached, drained, getCredit, getDesiredCapabilities, getDrain, getMaxMessageSize, getName, getOfferedCapabilities, getProperties, getQueued, getReceiverSettleMode, getRemoteCredit, getRemoteDesiredCapabilities, getRemoteMaxMessageSize, getRemoteOfferedCapabilities, getRemoteProperties, getRemoteReceiverSettleMode, getRemoteSenderSettleMode, getRemoteSource, getRemoteTarget, getSenderSettleMode, getSession, getSource, getTarget, getUnsettled, head, next, setDesiredCapabilities, setMaxMessageSize, setOfferedCapabilities, setProperties, setReceiverSettleMode, setRemoteSenderSettleMode, setSenderSettleMode, setSource, setTarget

Method Detail

flow

void flow(int credits)

Adds the specified number of credits. The number of link credits initialises to zero. It is the application's responsibility to call this method to allow the receiver to receive credits more deliveries.

recv

int recv(byte[] bytes,
         int offset,
         int size)

Receive message data for the current delivery. If the caller takes all the bytes the Receiver currently has for this delivery then it is removed from the Connection's work list. Before considering a delivery to be complete, the caller should examine Delivery.isPartial(). If the delivery is partial, the caller should call recv(byte[], int, int) again to receive the additional bytes once the Delivery appears again on the Connection work-list. TODO might the flags other than IO_WORK in DeliveryImpl also prevent the work list being pruned? e.g. what if a slow JMS consumer receives a disposition frame containing state=RELEASED? This is not IO_WORK.

Parameters:

bytes - the destination array where the message data is written

offset - index in the array to start writing data at

size - the maximum number of bytes to write

Returns:

number of bytes written. -1 if there are no more bytes for the current delivery.

See Also:

Link.current()

recv

int recv(WritableBuffer buffer)

Receive message data for the current delivery.

Parameters:

buffer - the buffer to write the message data.

Returns:

number of bytes written. -1 if there are no more bytes for the current delivery.

recv

ReadableBuffer recv()

Receive message data for the current delivery returning the data in a Readable buffer. The delivery will return an empty buffer if there is no pending data to be read or if all data has been read either by a previous call to this method or by a call to one of the other receive methods.

Returns:

a ReadableBuffer that contains the currently available data for the current delivery.

drain

void drain(int credit)

advance

boolean advance()

Attempts to advance the current delivery. Advances it to the next delivery if one exists, else null. The behaviour of this method is different for senders and receivers. TODO document what this method conceptually does and when you should use it.

Specified by:

advance in interface Link

Returns:

true if it can advance, false if it cannot TODO document the meaning of the return value more fully. Currently Senderimpl only returns false if there is no current delivery

draining

boolean draining()

setDrain

void setDrain(boolean drain)