org.jets3t.service.multi

Class ThreadWatcher

java.lang.Object

org.jets3t.service.multi.ThreadWatcher

Direct Known Subclasses:

ThreadWatcher

public class ThreadWatcher
extends Object

A thread watcher is associated with a multi-threaded operation and contains information about the progress of the operation.

As a minimum, this object will contain a count of the total number of threads involved in the operation (via getThreadCount()) and the count of threads that have already finished (via getCompletedThreads()).

For operations involving data transfer, such as uploads or downloads, this object may also include a count of the total bytes being transferred (via getBytesTotal()) and a count of how many bytes have already been transferred (via getBytesTransferred()). The availability of this information is indicated by the result of isBytesTransferredInfoAvailable().

Further data tranfer information may be also available, such as the current transfer rate (via getBytesPerSecond()) and an estimate of the time remaining until the transfer is completed (via getTimeRemaining()). The availability of this information is indicated by the result of isTimeRemainingAvailable().

It is possible to cancel some operations. If an operation may be cancelled, this object will include a CancelEventTrigger (available from getCancelEventListener()) which can be used to trigger a cancellation. Whether the operation can be cancelled is indicated by isCancelTaskSupported().

Author:

James Murty

Constructor Summary

Constructors

Constructor and Description
ThreadWatcher(BytesProgressWatcher[] progressWatchers)
ThreadWatcher(long threadCount)

Method Summary

Modifier and Type	Method and Description
void	cancelTask() Convenience method to trigger an event cancellation via CancelEventTrigger.cancelTask(java.lang.Object) if this thread watcher is associated with an operation that can be cancelled.
long	getBytesPerSecond()
long	getBytesTotal()
long	getBytesTransferred()
CancelEventTrigger	getCancelEventListener()
long	getCompletedThreads()
long	getThreadCount()
long	getTimeRemaining()
boolean	isBytesTransferredInfoAvailable() If this method returns true, the methods getBytesTotal() and getBytesTransferred() will contain information about the amount of data being transferred by the watched threads.
boolean	isCancelTaskSupported()
boolean	isTimeRemainingAvailable() If this method returns true, the method getTimeRemaining() will contain an estimate of the completion time for the data transfer.
void	updateThreadsCompletedCount(long completedThreads) Sets information about the number of threads completed and the total number of threads.
void	updateThreadsCompletedCount(long completedThreads, CancelEventTrigger cancelEventListener) Sets information about the number of threads completed and the total number of threads, as well as setting the cancellation listener that will be notified if the event is cancelled.

Methods inherited from class java.lang.Object

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

Constructor Detail

ThreadWatcher

public ThreadWatcher(BytesProgressWatcher[] progressWatchers)

ThreadWatcher

public ThreadWatcher(long threadCount)

Method Detail

updateThreadsCompletedCount

public void updateThreadsCompletedCount(long completedThreads)

Sets information about the number of threads completed and the total number of threads.

Parameters:

completedThreads - the number of threads that have completed.

updateThreadsCompletedCount

public void updateThreadsCompletedCount(long completedThreads,
                                        CancelEventTrigger cancelEventListener)

Sets information about the number of threads completed and the total number of threads, as well as setting the cancellation listener that will be notified if the event is cancelled.

Parameters:

completedThreads - the number of threads that have completed.

cancelEventListener - the listener to notify of cancellation events.

getCompletedThreads

public long getCompletedThreads()

Returns:

the number of threads that have completed.

getThreadCount

public long getThreadCount()

Returns:

the total number of threads involved in an operation.

isBytesTransferredInfoAvailable

public boolean isBytesTransferredInfoAvailable()

If this method returns true, the methods getBytesTotal() and getBytesTransferred() will contain information about the amount of data being transferred by the watched threads.

Returns:

true if this watcher contains information about the bytes transferred by the threads it is watching.

getBytesTotal

public long getBytesTotal()
                   throws IllegalStateException

Returns:

the expected total of bytes that will be transferred by the watched threads.

Throws:

IllegalStateException - if the bytes transferred information is not available - check this availability with the isBytesTransferredInfoAvailable() method.

getBytesTransferred

public long getBytesTransferred()

Returns:

the count of bytes that have been transferred by the watched threads.

Throws:

IllegalStateException - if the bytes transferred information is not available - check this availability with the isBytesTransferredInfoAvailable() method.

getBytesPerSecond

public long getBytesPerSecond()

Returns:

an estimate of the recent rate of bytes/second transfer speed.

isTimeRemainingAvailable

public boolean isTimeRemainingAvailable()

If this method returns true, the method getTimeRemaining() will contain an estimate of the completion time for the data transfer.

Returns:

true if this watcher contains an estimate of the completion time for the data transfer.

getTimeRemaining

public long getTimeRemaining()

Returns:

an estimate of the how many seconds until the data transfer completes, based on the overall byte rate of the transmission.

Throws:

IllegalStateException - if the time remaining estimave is not available - check this availability with the isTimeRemainingAvailable() method.

isCancelTaskSupported

public boolean isCancelTaskSupported()

Returns:

true if the operation this object is associated with can be cancelled, and a CancelEventTrigger is available.

cancelTask

public void cancelTask()

Convenience method to trigger an event cancellation via CancelEventTrigger.cancelTask(java.lang.Object) if this thread watcher is associated with an operation that can be cancelled.

getCancelEventListener

public CancelEventTrigger getCancelEventListener()

Returns:

the cancel event trigger associated with an operation, if any.