freenet.node

Interface PacketFormat

All Known Implementing Classes:

NewPacketFormat

public interface PacketFormat

Method Summary

Modifier and Type	Method and Description
boolean	canSend(SessionKey key) Returns false if the packet format can't send new messages because it must wait for some internal event.
void	checkForLostPackets()
boolean	fullPacketQueued(int maxPacketSize) Is there enough data queued to justify sending a packet immediately? Ideally this should take into account transport level headers.
boolean	handleReceivedPacket(byte[] buf, int offset, int length, long now, Peer replyTo)
boolean	maybeSendPacket(long now, boolean ackOnly) Maybe send something.
java.util.List<MessageItem>	onDisconnect() Called when the peer has been disconnected.
long	timeCheckForLostPackets()
long	timeNextUrgent(boolean canSend, long now)
long	timeSendAcks()

Method Detail

handleReceivedPacket

boolean handleReceivedPacket(byte[] buf,
                             int offset,
                             int length,
                             long now,
                             Peer replyTo)

maybeSendPacket

boolean maybeSendPacket(long now,
                        boolean ackOnly)
                 throws BlockedTooLongException

Maybe send something. A SINGLE PACKET. Don't send everything at once, for two reasons:

1. It is possible for a node to have a very long backlog.
2. Sometimes sending a packet can take a long time.
3. In the near future PacketSender will be responsible for output bandwidth throttling. So it makes sense to send a single packet and round-robin.

Parameters:

ackOnly -

Throws:

BlockedTooLongException

onDisconnect

java.util.List<MessageItem> onDisconnect()

Called when the peer has been disconnected. THE CALLER SHOULD STOP USING THE PACKET FORMAT OBJECT AFTER CALLING THIS FUNCTION!

canSend

boolean canSend(SessionKey key)

Returns false if the packet format can't send new messages because it must wait for some internal event. For example, if a packet sequence number can not be allocated this method should return false, but if nothing can be sent because there is no (external) data to send it should not. Note that this only applies to packets being created from messages on the @see PeerMessageQueue. Note also that there may already be messages in flight, but it may return false in that case, so you need to check timeNextUrgent() as well.

Returns:

false if the packet format can't send packets

timeNextUrgent

long timeNextUrgent(boolean canSend,
                    long now)

Parameters:

canSend - If false, canSend() has returned false. Some transports will want to send a packet anyway e.g. an ack, a resend in some cases.

Returns:

The time at which the packet format will want to send an ack, finish sending a message, retransmit a packet, or similar. Long.MAX_VALUE if not supported or if there is nothing to ack and nothing in flight.

timeSendAcks

long timeSendAcks()

Returns:

The time at which the packet format will want to send an ack. Resends etc don't count, only acks. The reason acks are special is they are needed for the other side to recognise that their packets have been received and thus avoid retransmission.

fullPacketQueued

boolean fullPacketQueued(int maxPacketSize)

Is there enough data queued to justify sending a packet immediately? Ideally this should take into account transport level headers.

checkForLostPackets

void checkForLostPackets()

timeCheckForLostPackets

long timeCheckForLostPackets()