ecologylab.concurrent
Class DownloadMonitor<T extends Downloadable>

java.lang.Object
  java.util.Observable
      ecologylab.generic.ObservableDebug
          ecologylab.concurrent.Monitor
              ecologylab.concurrent.DownloadMonitor<T>

All Implemented Interfaces:

DownloadProcessor<T>

public class DownloadMonitor<T extends Downloadable>
extends Monitor
implements DownloadProcessor<T>

Non-linear flow multiplexer. Tracks downloads of Downloadable objects. Dispatches downloaded media to the appropriate DispatchTarget.

Looks out for timeout conditions. In case they happen, records state in the bad slot, and dispatches, as well.

Field Summary

static int	HIGH_PRIORITY
static int	HIGHER_PRIORITY
static int	LOW_PRIORITY
static int	MAX_WAIT_TIME
static int	MID_PRIORITY

Constructor Summary

DownloadMonitor(java.lang.String name, int numDownloadThreads)

DownloadMonitor(java.lang.String name, int numDownloadThreads, int priorityBoost)

Method Summary

void	cancelDownload(Downloadable thatDownloadable) Cancel a download that has been queued, but not yet started.
void	clear() Stop performing downloads, and then Get rid of queued DownloadClosures.
void	download(T thatDownloadable, DispatchTarget<T> dispatchTarget) Entry point for Downloadables that want to be downloaded by 1 of our performDownload() threads.
StatusReporter	getStatus()
static NewPorterStemmer	getStemmer()
boolean	highNumberWaiting()
int	highPriority()
boolean	isPaused()
int	lowPriority()
boolean	midNumberWaiting()
int	midPriority()
void	pause()
void	pause(boolean paused)
int	pending()
void	printQueue()
void	setHurry(boolean hurry)
void	setNoWait(boolean noWait) Set whether or not this download monitor needs to wait after each download attempt
void	setStatus(StatusReporter status)
int	size()
void	stop()
void	stop(boolean kill) Stop our threads.
int	toDownloadSize() check the number of elements in the toDownload Queue
java.lang.String	toString()
void	unpause()
void	waitIfTooManyPending()
int	waitingToDownload()

Methods inherited from class ecologylab.concurrent.Monitor

done, notify, notifyAll, wait, wait, waitForDone

Methods inherited from class ecologylab.generic.ObservableDebug

debug, debug, debugA, debugA, debugI, debugI, error, getClassName, print, println, println, println, show, superString

Methods inherited from class java.util.Observable

addObserver, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

HIGHER_PRIORITY

public static final int HIGHER_PRIORITY

See Also:

Constant Field Values

HIGH_PRIORITY

public static final int HIGH_PRIORITY

See Also:

Constant Field Values

MID_PRIORITY

public static final int MID_PRIORITY

See Also:

Constant Field Values

LOW_PRIORITY

public static final int LOW_PRIORITY

See Also:

Constant Field Values

MAX_WAIT_TIME

public static final int MAX_WAIT_TIME

See Also:

Constant Field Values

Constructor Detail

DownloadMonitor

public DownloadMonitor(java.lang.String name,
                       int numDownloadThreads)

DownloadMonitor

public DownloadMonitor(java.lang.String name,
                       int numDownloadThreads,
                       int priorityBoost)

Method Detail

download

public void download(T thatDownloadable,
                     DispatchTarget<T> dispatchTarget)

Entry point for Downloadables that want to be downloaded by 1 of our performDownload() threads. Starts the performDownload() threads, if necessary.

After performDownload() is called on the Downloadable, then in the normal case, downloadDone() is called, and then the DispatchTarget is called. In the error case, handleIOError() or handleTimeout() is called.

Specified by:

download in interface DownloadProcessor<T extends Downloadable>

cancelDownload

public void cancelDownload(Downloadable thatDownloadable)

Cancel a download that has been queued, but not yet started.

Parameters:

thatDownloadable -

pause

public void pause()

unpause

public void unpause()

pause

public void pause(boolean paused)

toString

public java.lang.String toString()

Overrides:

toString in class ObservableDebug

stop

public void stop()

Specified by:

stop in interface DownloadProcessor<T extends Downloadable>

stop

public void stop(boolean kill)

Stop our threads.

waitingToDownload

public int waitingToDownload()

highNumberWaiting

public boolean highNumberWaiting()

Returns:

true if we're backed up with unresloved downloads.

midNumberWaiting

public boolean midNumberWaiting()

lowPriority

public int lowPriority()

midPriority

public int midPriority()

highPriority

public int highPriority()

pending

public int pending()

setNoWait

public void setNoWait(boolean noWait)

Set whether or not this download monitor needs to wait after each download attempt

Parameters:

noWait -

setHurry

public void setHurry(boolean hurry)

getStemmer

public static NewPorterStemmer getStemmer()

toDownloadSize

public int toDownloadSize()

check the number of elements in the toDownload Queue

Returns:

clear

public void clear()

Stop performing downloads, and then Get rid of queued DownloadClosures.

waitIfTooManyPending

public void waitIfTooManyPending()

printQueue

public void printQueue()

getStatus

public StatusReporter getStatus()

setStatus

public void setStatus(StatusReporter status)

isPaused

public boolean isPaused()

Returns:

the paused

size

public int size()