ecologylab.services.distributed.impl
Class NIOServerBackend

java.lang.Object
  ecologylab.generic.Debug
      ecologylab.services.distributed.impl.NIOCore
          ecologylab.services.distributed.impl.NIONetworking
              ecologylab.services.distributed.impl.NIOServerBackend

All Implemented Interfaces:

StartAndStoppable, NetworkingConstants, ServerConstants, java.lang.Runnable

public class NIOServerBackend
extends NIONetworking
implements ServerConstants

The backend portion of the NIO Server, which handles low-level communication with clients. Re-written based on the Rox Java NIO Tutorial (http://rox-xmlrpc.sourceforge.net/niotut/index.html).

Author:

Zachary O. Toups (toupsz@cs.tamu.edu)

Field Summary

protected java.net.ServerSocket[]

incomingConnectionSockets

Fields inherited from class ecologylab.services.distributed.impl.NIONetworking

byteBufferPool, connectionCount, objectRegistry, shuttingDown, translationSpace

Fields inherited from class ecologylab.services.distributed.impl.NIOCore

portNumber, selector

Fields inherited from interface ecologylab.services.distributed.common.ServerConstants

GARBAGE_CONNECTION_CLEANUP_TIMEOUT, MAX_CONNECTIONS, MAXIMUM_TRANSMISSION_ERRORS

Fields inherited from interface ecologylab.services.distributed.common.NetworkingConstants

CHARACTER_ENCODING, CONTENT_LENGTH_STRING, CONTENT_LENGTH_STRING_LENGTH, DECODER, ENCODER, HTTP_HEADER_LINE_DELIMITER, HTTP_HEADER_TERMINATOR, MAX_HTTP_HEADER_LENGTH, MAX_PACKET_SIZE_BYTES, MAX_PACKET_SIZE_CHARACTERS, UNIQUE_IDENTIFIER_STRING

Constructor Summary

protected

NIOServerBackend(int portNumber, java.net.InetAddress[] hostAddresses, NIOServerFrontend sAP, TranslationSpace requestTranslationSpace, Scope<?> objectRegistry, int idleSocketTimeout)

Method Summary

void	acceptFinished(java.nio.channels.SelectionKey key) Queues a request to change key's interest operations back to READ.
protected void	acceptKey(java.nio.channels.SelectionKey key) Optional operation.
protected void	acceptReady(java.nio.channels.SelectionKey key)
protected void	checkAndDropIdleKeys() Checks all of the current keys to see if they have been idle for too long and drops them if they have.
protected void	close()
protected void	connectReady(java.nio.channels.SelectionKey key)
protected java.lang.String	generateSessionToken(java.net.Socket incomingSocket) Generates a unique identifier String for the given socket, based upon actual ports used and ip addresses with a hash.
java.net.InetAddress[]	getHostAddresses() Gets all host addresses associated with this server.
protected void	invalidateKey(java.nio.channels.SelectionKey key, boolean permanent)
protected void	processReadData(java.lang.Object sessionId, java.nio.channels.SelectionKey sk, java.nio.ByteBuffer bytes, int bytesRead) This method is called whenever bytes have been read from a socket.
protected void	readFinished(java.nio.channels.SelectionKey key)
protected void	removeBadConnections(java.nio.channels.SelectionKey key)
void	setPendingInvalidate(java.nio.channels.SocketChannel socket, boolean permanent)

Methods inherited from class ecologylab.services.distributed.impl.NIONetworking

acquireByteBufferFromPool, connectionTerminated, enqueueBytesForWriting, readReady, terminationAction, writeKey, writeReady

Methods inherited from class ecologylab.services.distributed.impl.NIOCore

connectFinished, getPortNumber, invalidateKey, queueForAccept, queueForConnect, queueForRead, queueForWrite, run, setPendingInvalidate, start, stop, writeFinished

Methods inherited from class ecologylab.generic.Debug

classSimpleName, closeLoggingFile, debug, debug, debug, debug, debugA, debugA, debugA, debugI, debugI, debugI, error, error, getClassName, getClassName, getInteractive, getPackageName, getPackageName, getPackageName, initialize, level, level, level, logToFile, print, print, println, println, println, println, println, println, printlnA, printlnA, printlnA, printlnI, printlnI, printlnI, printlnI, setLoggingFile, show, show, superString, toggleInteractive, toString, toString, warning, warning, weird, weird

Methods inherited from class java.lang.Object

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

Field Detail

incomingConnectionSockets

protected java.net.ServerSocket[] incomingConnectionSockets

Constructor Detail

NIOServerBackend

protected NIOServerBackend(int portNumber,
                           java.net.InetAddress[] hostAddresses,
                           NIOServerFrontend sAP,
                           TranslationSpace requestTranslationSpace,
                           Scope<?> objectRegistry,
                           int idleSocketTimeout)
                    throws java.io.IOException,
                           java.net.BindException

Throws:

java.io.IOException

java.net.BindException

Method Detail

getHostAddresses

public java.net.InetAddress[] getHostAddresses()

Gets all host addresses associated with this server.

Returns:

checkAndDropIdleKeys

protected void checkAndDropIdleKeys()

Checks all of the current keys to see if they have been idle for too long and drops them if they have.

Specified by:

checkAndDropIdleKeys in class NIOCore

acceptKey

protected final void acceptKey(java.nio.channels.SelectionKey key)

Description copied from class: NIONetworking

Optional operation. Called when a key has been marked for accepting. This method should be implemented by servers, but clients should leave this blank, unless they are also acting as servers (accepting incoming connections).

Specified by:

acceptKey in class NIONetworking

removeBadConnections

protected void removeBadConnections(java.nio.channels.SelectionKey key)

Specified by:

removeBadConnections in class NIOCore

See Also:

ecologylab.services.distributed.impl.NIONetworking#removeBadConnections()

invalidateKey

protected void invalidateKey(java.nio.channels.SelectionKey key,
                             boolean permanent)

Specified by:

invalidateKey in class NIOCore

See Also:

ecologylab.services.distributed.impl.NIONetworking#invalidateKey(java.nio.channels.SocketChannel, boolean)

generateSessionToken

protected java.lang.String generateSessionToken(java.net.Socket incomingSocket)

Generates a unique identifier String for the given socket, based upon actual ports used and ip addresses with a hash.

Parameters:

incomingSocket -

Returns:

close

protected void close()

Overrides:

close in class NIOCore

processReadData

protected void processReadData(java.lang.Object sessionId,
                               java.nio.channels.SelectionKey sk,
                               java.nio.ByteBuffer bytes,
                               int bytesRead)
                        throws BadClientException

Description copied from class: NIONetworking

This method is called whenever bytes have been read from a socket. There is no guaranty that the bytes will be a valid or complete message, nor is there a guaranty about what said bytes encode. Implementations should be prepared to handle incomplete messages, multiple messages, or malformed messages in this method.

Specified by:

processReadData in class NIONetworking

Parameters:

sessionId - the id being use for this session.

bytes - the bytes read from the SocketChannel.

bytesRead - the number of bytes in the bytes array.

Throws:

BadClientException - if the client from which the bytes were read has transmitted something inappropriate, such as data too large for a buffer or a possibly malicious message.

acceptReady

protected void acceptReady(java.nio.channels.SelectionKey key)

Specified by:

acceptReady in class NIOCore

See Also:

NIOCore.acceptReady(java.nio.channels.SelectionKey)

connectReady

protected void connectReady(java.nio.channels.SelectionKey key)

Specified by:

connectReady in class NIOCore

See Also:

NIOCore.connectReady(java.nio.channels.SelectionKey)

readFinished

protected void readFinished(java.nio.channels.SelectionKey key)

Specified by:

readFinished in class NIOCore

See Also:

NIOCore.readFinished(java.nio.channels.SelectionKey)

setPendingInvalidate

public void setPendingInvalidate(java.nio.channels.SocketChannel socket,
                                 boolean permanent)

Parameters:

socket -

permanent -

acceptFinished

public void acceptFinished(java.nio.channels.SelectionKey key)

Description copied from class: NIOCore

Queues a request to change key's interest operations back to READ. This method is automatically called after acceptReady(SelectionKey) in the main operating loop.

Specified by:

acceptFinished in class NIOCore

See Also:

NIOCore.acceptFinished(java.nio.channels.SelectionKey)