CADI.Server.Core
Class Worker

java.lang.Object
  java.lang.Thread
      CADI.Server.Core.Worker

All Implemented Interfaces:

StatusCodes, EORCodes, java.lang.Runnable

public class Worker
extends java.lang.Thread
implements StatusCodes, EORCodes

This class performs the client request processing and it sends the server response to the client. It does the following tasks: manages the client sessions, manages logical targets, check restrictions, sends the response (data or errors), etc.

This thread is launched and it will be waiting for a task. Tasks are passed to this worker through a TaskQueue queue (the Scheduler puts the task into the queue and the Worker get them).

This thread is always running or waiting for a task. Therefore, it only can be finished if the finish is set to true.

Usage example:
construct
setParameters
run
....
finish


Version:

1.1.2 2009/08/15

Author:

Group on Interactive Coding of Images (GICI)

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

private boolean	busy Indicates if the thread is carrying out a task.
private java.lang.String	cachePath Is the path directory that will be used to save the temporary files used to cache client data.
private static java.lang.String	channelFieldPath
private int	deliveryProgressionOrder Is the progression order which will be used to delivery the data.
private boolean	finish Indicates whether the thread has to finish when it is working with a request with the keep-alive mode set.
private HTTPRequest	httpRequest Definition in HTTPRequest.
private HTTPResponse	httpResponse
private HTTPResponseSender	httpResponseSender
private boolean	independentMessageHeaders Definition in JPIPMessageEncoder.independentForm.
private boolean	initializeCache This attribute is used in the logicalTargetsManager(String, String) and the cacheManager() methods to indicate if the cache must be created.
private long	initStageTime Used for verbose information (time for stage).
private long	initTime Used for verbose information (total time).
private boolean	isStatelessRequest Indicates whether the actual request is a stateles request or a request with a session.
private JPIPRequestFields	jpipRequestFields Definition in JPIPRequestFields.
private JPIPResponseFields	jpipResponseFields
private int	keepAliveTimeout Definition in Scheduler.keepAliveTimeout.
private ClientSessions	listOfClientSessions Definition in Scheduler.clientSessions.
private CADILog	log Definition in Scheduler.log.
private ServerLogicalTarget	logicalTarget Contains a pointer to the parameters of the logical target which is being requested.
private LogicalTargetList	logicalTargetList Definition in Scheduler.logicalTargetList.
private float	maxTxRate Definition in Scheduler.maxTxRate.
private java.io.OutputStream	os Is an output stream that will be used to send the server response to the client.
private int	rateDistortionMethod Definition in JP2LogicalTarget.rateDistortionMethod.
private int	RDSubType Indicates a type within the rate distortion method.
private boolean	sendLogicalTargetData
private ServerCache	serverCache
private ServerLogicalTargetManager	serverLogicalTargetManager
private Session	session Contains the session object where is data about the actual session is saved.
private java.lang.String	sessionID It is the session identifier of the request which is being processed.
private boolean	setTID
private java.net.Socket	socket Contains the client socket of which request is being processed.
private java.lang.String	targetsPath Is the path directory where the logical targets are stored.
private TasksQueue	tasksQueue Definition in Scheduler.tasksQueue

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Fields inherited from interface CADI.Common.Network.HTTP.StatusCodes

ACCEPTED, BAD_REQUEST, NOT_FOUND, NOT_IMPLEMENTED, OK, SERVICE_UNAVAILABLE, UNSUPPORTED_MEDIA_TYPE

Fields inherited from interface CADI.Common.Network.JPIP.EORCodes

BYTE_LIMIT_REACHED, IMAGE_CHANGE, IMAGE_DONE, NON_ESPECIFIED_REASON, QUALITY_LIMIT_REACHED, RESPONSE_LIMIT_REACHED, SESSION_LIMIT_REACHED, WINDOW_DONE

Constructor Summary

Worker(java.lang.String threadName, TasksQueue tasksQueue, LogicalTargetList logicalTargetList, ClientSessions clientSessions, CADILog log)
Constructor.

Method Summary

private java.lang.String[]	availableReturnTypes() Gets the available image return types.
private void	cacheManager() This method is used to manage the caches when a session is created or when a cache needs to be update with data received from the client.
private void	checkJPIPParameters() This method tests several JPIP restrictions of the parameters
private void	closeChannels(java.lang.String cid, java.lang.String[] cclose) This method is used to close session channels.
private void	encodeJPIPResponseFields() JPIP HEADERS (See ISO/IEC 15444-9 Annex D)
void	finish() This method is used to indicate that the thread has to finish.
java.lang.Thread.State	getState()
boolean	isBusy() This method is used to indicate if the thread is or no busy processing a task.
private void	listenNewRequest() This method will be used to read a HTTP client request.
private void	logicalTargetsManager(java.lang.String target, java.lang.String tid) This method is used to manage the list of loaded targets.
private void	processRequest() This method performs the core to process the client requests.
private void	resetTime() Set the time attributes to 0.
void	run() This method implements the control of the thread.
private void	sendHTTPResponseError(int statusCode, java.lang.String reasonPhrase) This method will be used to send an HTTP error response to the client.
private void	sendHTTPResponseHeader(HTTPResponse httpResponse)
void	sessionsManager() This method is used to manage the client sessions.
void	setCachePath(java.lang.String cachePath) Sets the cachePath attribute.
void	setDeliveryProgressionOrder(int deliveryProgressionOrder) Sets the deliveryProgressionOrder attribute.
void	setIndependentMessageHeaders(boolean independentMessageHeaders) Sets the #independentMesssageHeaders attribute.
void	setKeepAliveTimeout(int keepAliveTimeout) Sets the keepAliveTimeout attribute.
void	setMaxTxRate(float maxTxRate) Sets the maxTxRate attribute.
void	setRateDistortionMethod(int rateDistortionMethod, int RDSubType) Sets the rate-distortion method and the subrate-distortion method.
void	setTargetsPath(java.lang.String targetsPath) Sets the targetsPath attribute.
private java.lang.String	showTimeMemory(java.lang.String stage) Show some time and memory usage statisticals.
private void	updateCache(java.util.ArrayList jpipMessageData) This method is used to update the cache with the data that has been sent to the client.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

tasksQueue

private TasksQueue tasksQueue

Definition in Scheduler.tasksQueue

logicalTargetList

private LogicalTargetList logicalTargetList

Definition in Scheduler.logicalTargetList.

listOfClientSessions

private ClientSessions listOfClientSessions

Definition in Scheduler.clientSessions.

log

private CADILog log

Definition in Scheduler.log.

targetsPath

private java.lang.String targetsPath

Is the path directory where the logical targets are stored.

cachePath

private java.lang.String cachePath

Is the path directory that will be used to save the temporary files used to cache client data.

rateDistortionMethod

private int rateDistortionMethod

Definition in JP2LogicalTarget.rateDistortionMethod.

RDSubType

private int RDSubType

Indicates a type within the rate distortion method.

deliveryProgressionOrder

private int deliveryProgressionOrder

Is the progression order which will be used to delivery the data. If this parameters is not set, the default file codestream order will be used.

keepAliveTimeout

private int keepAliveTimeout

Definition in Scheduler.keepAliveTimeout.

maxTxRate

private float maxTxRate

Definition in Scheduler.maxTxRate.

independentMessageHeaders

private boolean independentMessageHeaders

Definition in JPIPMessageEncoder.independentForm.

socket

private java.net.Socket socket

Contains the client socket of which request is being processed.

httpRequest

private HTTPRequest httpRequest

Definition in HTTPRequest.

jpipRequestFields

private JPIPRequestFields jpipRequestFields

Definition in JPIPRequestFields.

finish

private boolean finish

Indicates whether the thread has to finish when it is working with a request with the keep-alive mode set.

See Also:

finish()

busy

private boolean busy

Indicates if the thread is carrying out a task. If the thread is waiting for a new task, the busy attribute is false.

os

private java.io.OutputStream os

Is an output stream that will be used to send the server response to the client.

httpResponseSender

private HTTPResponseSender httpResponseSender

httpResponse

private HTTPResponse httpResponse

jpipResponseFields

private JPIPResponseFields jpipResponseFields

logicalTarget

private ServerLogicalTarget logicalTarget

Contains a pointer to the parameters of the logical target which is being requested.

serverLogicalTargetManager

private ServerLogicalTargetManager serverLogicalTargetManager

serverCache

private ServerCache serverCache

initializeCache

private boolean initializeCache

This attribute is used in the logicalTargetsManager(String, String) and the cacheManager() methods to indicate if the cache must be created.

isStatelessRequest

private boolean isStatelessRequest

Indicates whether the actual request is a stateles request or a request with a session.

session

private Session session

Contains the session object where is data about the actual session is saved.

sessionID

private java.lang.String sessionID

It is the session identifier of the request which is being processed.

setTID

private boolean setTID

sendLogicalTargetData

private boolean sendLogicalTargetData

channelFieldPath

private static java.lang.String channelFieldPath

initStageTime

private long initStageTime

Used for verbose information (time for stage).

0 is initial time.

initTime

private long initTime

Used for verbose information (total time).

0 is initial time.

Constructor Detail

Worker

public Worker(java.lang.String threadName,
              TasksQueue tasksQueue,
              LogicalTargetList logicalTargetList,
              ClientSessions clientSessions,
              CADILog log)

Constructor.

Parameters:

threadName - is a string with the name of the thread.

tasksQueue - definition in tasksQueue.

logicalTargetList - definition in logicalTargetList.

clientSessions - definition in listOfClientSessions.

log - definition in log.

Method Detail

setTargetsPath

public void setTargetsPath(java.lang.String targetsPath)

Sets the targetsPath attribute.

Parameters:

targetsPath - definition in targetsPath.

setCachePath

public void setCachePath(java.lang.String cachePath)

Sets the cachePath attribute.

Parameters:

cachePath - definition in cachePath.

setRateDistortionMethod

public void setRateDistortionMethod(int rateDistortionMethod,
                                    int RDSubType)

Sets the rate-distortion method and the subrate-distortion method.

Parameters:

rateDistortionMethod - definition in rateDistortionMethod.

RDSubType - definition in RDSubType.

setDeliveryProgressionOrder

public void setDeliveryProgressionOrder(int deliveryProgressionOrder)

Sets the deliveryProgressionOrder attribute.

Parameters:

deliveryProgressionOrder - definition in deliveryProgressionOrder.

setKeepAliveTimeout

public void setKeepAliveTimeout(int keepAliveTimeout)

Sets the keepAliveTimeout attribute.

Parameters:

keepAliveTimeout - definition in keepAliveTimeout.

setMaxTxRate

public void setMaxTxRate(float maxTxRate)

Sets the maxTxRate attribute.

Parameters:

maxTxRate - definition in maxTxRate attribute.

setIndependentMessageHeaders

public void setIndependentMessageHeaders(boolean independentMessageHeaders)

Sets the #independentMesssageHeaders attribute.

Parameters:

independentMesssageHeaders - definition in #independentMesssageHeaders attribute.

run

public void run()

This method implements the control of the thread.

When the Scheduler assigns a task, it will be awake. The task may be:

• Process a client request.
• Sends a message error to the client.

Moreover, when the keep-alive mode of a client request is set, the thread is dedicated to wait for a new request until the timeout value is reached.

The thread will be running until the finish attribute is false.

Specified by:

run in interface java.lang.Runnable

Overrides:

run in class java.lang.Thread

finish

public void finish()

This method is used to indicate that the thread has to finish.

isBusy

public boolean isBusy()

This method is used to indicate if the thread is or no busy processing a task.

Returns:

true if the thread is processing a task. Otherwise, it returns false.

getState

public java.lang.Thread.State getState()

Overrides:

getState in class java.lang.Thread

processRequest

private void processRequest()
                     throws WarningException

This method performs the core to process the client requests. It is a manager that uses several auxiliary classess and methods to process the client request and to make the server response.

Throws:

WarningException

sessionsManager

public void sessionsManager()
                     throws WarningException

This method is used to manage the client sessions.

Tests if it is a stateless request, if it is a request which belongs to a previous session, or it is a request for a new session. When a stateless request is used, a temporary session is created and it must be removed when the request process finishes. When the request is for a new session, a new entry in the listOfClientSessions is created with the client preferences and capabilities. And if the request belongs to a previous session, then, client data (logical target, image return type, cache, preferences, capabilites, etc. ) are read from the listOfClientSessions.

When an error in the request is found (p.e. session identifier does not exist or are wrong, logical target does not exist, etc.), an error message is sent to the client and a WarningException is thrown.

Throws:

WarningException - when something anomalous (p.e. session identifier does not exist or are wrong, logical target does not exist, etc.) this exception will be thrown.

logicalTargetsManager

private void logicalTargetsManager(java.lang.String target,
                                   java.lang.String tid)
                            throws WarningException

This method is used to manage the list of loaded targets. The targed will be passed through the jpip target field, the jpip tid field, or both.

If the requested target has been loaded in a previous request, it will be in the list of loaded targets. So, its parameters will be recovered from that list.

Otherwise, target will be searched in disk. And if it is in disk, it will be loaded to the list.

Parameters:

target - definition in TargetField.target

tid - definition in TargetField.tid

Throws:

WarningException

cacheManager

private void cacheManager()

This method is used to manage the caches when a session is created or when a cache needs to be update with data received from the client.

listenNewRequest

private void listenNewRequest()
                       throws WarningException,
                              ErrorException

This method will be used to read a HTTP client request. It will be used when the HTTP keep-alive mode is set. Then, this thread is assigned to this client. The received request data will be stored in the httpRequestFields (see

Throws:

WarningException - when an

ErrorException - when the client has closed the socket, the socket reaches its timeout, or an I/O error has occured while client request was being received.

sendHTTPResponseHeader

private void sendHTTPResponseHeader(HTTPResponse httpResponse)
                             throws WarningException

Parameters:

httpResponse -

Throws:

WarningException

sendHTTPResponseError

private void sendHTTPResponseError(int statusCode,
                                   java.lang.String reasonPhrase)

This method will be used to send an HTTP error response to the client.

Parameters:

statusCode - definition in StatusCodes.

reasonPhrase - a reason phrase related with the status code.

encodeJPIPResponseFields

private void encodeJPIPResponseFields()

JPIP HEADERS (See ISO/IEC 15444-9 Annex D)

checkJPIPParameters

private void checkJPIPParameters()
                          throws WarningException

This method tests several JPIP restrictions of the parameters

Throws:

WarningException

closeChannels

private void closeChannels(java.lang.String cid,
                           java.lang.String[] cclose)

This method is used to close session channels.

Parameters:

cid - definition in ChannelField.cid

cclose - definition in ChannelField.cclose

updateCache

private void updateCache(java.util.ArrayList jpipMessageData)

This method is used to update the cache with the data that has been sent to the client. Therefore, it must be called after the response has been sent to the client.

Parameters:

jpipMessageData - an array list with the data that has been sent.

availableReturnTypes

private java.lang.String[] availableReturnTypes()

Gets the available image return types.

Returns:

returns an one-dimension array with the available return types.

resetTime

private void resetTime()

Set the time attributes to 0.

showTimeMemory

private java.lang.String showTimeMemory(java.lang.String stage)

Show some time and memory usage statisticals.

Parameters:

stage - string that will be displayed