Package net.i2p.client.streaming.impl

Class ConnectionDataReceiver

java.lang.Object

net.i2p.client.streaming.impl.ConnectionDataReceiver

All Implemented Interfaces:

MessageOutputStream.DataReceiver

class ConnectionDataReceiver
extends Object
implements MessageOutputStream.DataReceiver

Receive data from the MessageOutputStream, build a packet, and send it through a connection. The write calls on this do NOT block, but they also do not necessary imply immediate delivery, or even the generation of a new packet. This class is the only one that builds useful outbound Packet objects.

MessageOutputStream -> ConnectionDataReceiver -> Connection -> PacketQueue -> I2PSession

There's one of these per MessageOutputStream. It stores no state. It sends everything to the Connection unless the Connection is closed,

Constructor Summary

Constructors

Constructor	Description
ConnectionDataReceiver(I2PAppContext ctx, Connection con)

Method Summary

Modifier and Type	Method	Description
(package private) void	destroy()
PacketLocal	send(byte[] buf, int off, int size)	Send some data through the connection, attaching any appropriate flags onto the packet.
PacketLocal	send(byte[] buf, int off, int size, boolean forceIncrement)	Called externally from Connection with args (null, 0, 0, true) to send an empty data packet
MessageOutputStream.WriteStatus	writeData(byte[] buf, int off, int size)	Send some data through the connection, or if there is no new data, this may generate a packet with a plain ACK/NACK or CLOSE, or nothing whatsoever if there's nothing new to send.
boolean	writeInProcess()	This tells the flusher in MessageOutputStream whether to flush.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConnectionDataReceiver

public ConnectionDataReceiver(I2PAppContext ctx,
                              Connection con)

Parameters:

con - non-null

Method Detail

writeInProcess

public boolean writeInProcess()

This tells the flusher in MessageOutputStream whether to flush. It won't flush if this returns true. It was: return con.getUnackedPacketsSent() > 0 (i.e. Nagle) But then, for data that fills more than one packet, the last part of the data isn't sent until all the previous packets are acked. Which is very slow. The poor interaction of Nagle and Delayed Acknowledgements is well-documented. So let's send data along unless the outbound window is full. (i.e. no-Nagle or TCP_NODELAY) Probably should have a configuration option for this.

Specified by:

writeInProcess in interface MessageOutputStream.DataReceiver

Returns:

!flush

writeData

public MessageOutputStream.WriteStatus writeData(byte[] buf,
                                                 int off,
                                                 int size)

Send some data through the connection, or if there is no new data, this may generate a packet with a plain ACK/NACK or CLOSE, or nothing whatsoever if there's nothing new to send. This is called from MessageOutputStream, i.e. data from the client.

Specified by:

writeData in interface MessageOutputStream.DataReceiver

Parameters:

buf - data to be sent - may be null

off - offset into the buffer to start writing from

size - how many bytes of the buffer to write (may be 0)

Returns:

an object to allow optional blocking for data acceptance or delivery.

send

public PacketLocal send(byte[] buf,
                        int off,
                        int size)

Send some data through the connection, attaching any appropriate flags onto the packet. Called externally from Connection with args (null, 0, 0) to send an ack

Parameters:

buf - data to be sent - may be null

off - offset into the buffer to start writing from

size - how many bytes of the buffer to write (may be 0)

Returns:

the packet sent

send

public PacketLocal send(byte[] buf,
                        int off,
                        int size,
                        boolean forceIncrement)

Called externally from Connection with args (null, 0, 0, true) to send an empty data packet

Parameters:

buf - data to be sent - may be null

off - offset into the buffer to start writing from

size - how many bytes of the buffer to write (may be 0)

forceIncrement - even if the buffer is empty, increment the packetId so we get an ACK back

Returns:

the packet sent

destroy

void destroy()