siena.comm

Class KAPacketReceiver

java.lang.Object

siena.comm.KAPacketReceiver

All Implemented Interfaces:

PacketReceiver

Direct Known Subclasses:

KAZipPacketReceiver, SSLPacketReceiver

public class KAPacketReceiver
extends java.lang.Object
implements PacketReceiver

receives packets through a TCP port. Uses persistent TCP connections to receive one or more packets.

Field Summary

Fields

Modifier and Type	Field and Description
static int	AcceptPollingInterval controls the accept-close workaround.
static int	DefaultMaxActiveConnections default limit for active connections.
static int	DefaultPort
static int	DefaultReceiveTimeout default value for the receive timeout.
int	receive_timeout limits the duration of blocking input when receiving packets.
static java.lang.String	Schema

Constructor Summary

Constructors

Constructor and Description
KAPacketReceiver() creates a receiver listening to the a random port.
KAPacketReceiver(int port_number) creates a receiver listening to the given port.
KAPacketReceiver(int port_number, int qsize) creates a receiver listening to the given port with a given maximum queue for TCP connections.
KAPacketReceiver(java.net.ServerSocket s) creates a receiver listening to the given port.

Method Summary

Methods

Modifier and Type	Method and Description
byte[]	address() external address of this packet receiver.
protected static java.net.InetAddress	guessMyIPAddress()
protected static java.net.InetAddress	guessMyIPAddress(java.net.DatagramSocket s)
protected static java.net.InetAddress	guessMyIPAddress(java.net.ServerSocket s)
int	receive(byte[] buf) receives a packet in the given buffer.
int	receive(byte[] buf, long timeout) not yet implemented.
static int	receive(java.net.Socket sock, byte[] buf)
void	setHostName(java.lang.String hostname) explicitly sets the address of this packet receiver.
void	setMaxActiveConnections(int m) limits the number of active connections.
void	shutdown() closes the receiver.

Methods inherited from class java.lang.Object

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

Methods inherited from interface siena.comm.PacketReceiver

address

Field Detail

Schema

public static final java.lang.String Schema

See Also:

Constant Field Values

DefaultPort

public static final int DefaultPort

See Also:

Constant Field Values

AcceptPollingInterval

public static int AcceptPollingInterval

controls the accept-close workaround. See TCPPacketReceiver.AcceptPollingInterval for an explanation of this parameter.

DefaultReceiveTimeout

public static int DefaultReceiveTimeout

default value for the receive timeout.

See Also:

receive_timeout

receive_timeout

public int receive_timeout

limits the duration of blocking input when receiving packets. A positive value defines a timeout for receive operations for this receiver. This parameter affects new connections only. A value <=0 means infinite timeout.

DefaultMaxActiveConnections

public static int DefaultMaxActiveConnections

default limit for active connections.

See Also:

setMaxActiveConnections(int)

Constructor Detail

KAPacketReceiver

public KAPacketReceiver()
                 throws java.io.IOException

creates a receiver listening to the a random port.

Throws:

java.io.IOException - if an I/O error occurs when opening the socket port.

KAPacketReceiver

public KAPacketReceiver(int port_number)
                 throws java.io.IOException

creates a receiver listening to the given port.

Parameters:

port_number - must be a valid TCP port number, or it can be 0 in which case a random port is used

Throws:

java.io.IOException - if an I/O error occurs when opening the socket. typically, when the given port is already in use.

KAPacketReceiver

public KAPacketReceiver(int port_number,
                int qsize)
                 throws java.io.IOException

creates a receiver listening to the given port with a given maximum queue for TCP connections.

Parameters:

port_number - must be a valid TCP port number, or it can be 0 in which case a random port is used

Throws:

java.io.IOException - if an I/O error occurs when opening the socket. typically, when the given port is already in use.

KAPacketReceiver

public KAPacketReceiver(java.net.ServerSocket s)
                 throws java.io.IOException

creates a receiver listening to the given port.

Parameters:

s - server socket used to accept connections.

Throws:

java.net.UnknownHostException - if an error occurrs while resolving the hostname for this host.

java.io.IOException

Method Detail

setMaxActiveConnections

public void setMaxActiveConnections(int m)

limits the number of active connections. This receiver will maintain at most m active connections. If a new connection is accepted when m connections are active, the new accepted connections will replace the oldest active connection.

When the limit is lowered and x > m connections are active, the oldest x - m connections are closed.

setHostName

public void setHostName(java.lang.String hostname)

explicitly sets the address of this packet receiver. This method allows users to set the host name or IP address that this receiver advertises as its externally-visible address. This might be necessary in the cases in which the Java VM can not reliably figure out such an address by itself.

receive

public int receive(byte[] buf)
            throws PacketReceiverException

Description copied from interface: PacketReceiver

receives a packet in the given buffer. This method must be reentrant. Siena clients and servers must be able to use several threads to receive packets from the same receiver.

Specified by:

receive in interface PacketReceiver

Returns:

the number of bytes read into the buffer. The return value must not be negative. On error conditions, this method must throw an exception.

Throws:

PacketReceiverException - in case an error occurrs while reading.

receive

public int receive(byte[] buf,
          long timeout)

not yet implemented.

Specified by:

receive in interface PacketReceiver

Returns:

the number of bytes read into the buffer. The return value must not be negative. On error conditions, this method must throw an exception.

shutdown

public void shutdown()
              throws PacketReceiverException

Description copied from interface: PacketReceiver

closes the receiver.

Specified by:

shutdown in interface PacketReceiver

Throws:

PacketReceiverException

receive

public static int receive(java.net.Socket sock,
          byte[] buf)
                   throws java.lang.InterruptedException,
                          java.io.IOException

Throws:

java.lang.InterruptedException

java.io.IOException

address

public byte[] address()

external address of this packet receiver. Uses the following schema syntax:
schema:host:port

See Also:

PacketReceiver.address()

guessMyIPAddress

protected static java.net.InetAddress guessMyIPAddress()
                                                throws java.net.UnknownHostException

Throws:

java.net.UnknownHostException

guessMyIPAddress

protected static java.net.InetAddress guessMyIPAddress(java.net.ServerSocket s)
                                                throws java.net.UnknownHostException

Throws:

java.net.UnknownHostException

guessMyIPAddress

protected static java.net.InetAddress guessMyIPAddress(java.net.DatagramSocket s)
                                                throws java.net.UnknownHostException

Throws:

java.net.UnknownHostException