org.jasig.portal
Class ChannelRenderer

java.lang.Object
  org.jasig.portal.ChannelRenderer

All Implemented Interfaces:

IDynamicChannelTitleRenderer, IChannelRenderer

public class ChannelRenderer
extends java.lang.Object
implements IChannelRenderer, IDynamicChannelTitleRenderer

This class takes care of initiating channel rendering thread, monitoring it for timeouts, retreiving cache, and returning rendering results and status.

Version:

$Revision: 1.45.2.7 $

Author:

Peter Kharchenko

Nested Class Summary

protected class

ChannelRenderer.Worker

Field Summary

static boolean	CACHE_CHANNELS
protected java.util.Map	cacheTables
protected boolean	ccacheable
protected IChannel	channel
protected java.util.Map	channelCache
private static boolean	DEFAULT_CACHE_CHANNELS Default value for CACHE_CHANNELS.
protected boolean	donerendering
protected java.lang.Object	groupRenderingKey
protected SetCheckInSemaphore	groupSemaphore
protected org.apache.commons.logging.Log	log
protected ChannelRuntimeData	rd
protected boolean	rendering
static java.lang.String[]	renderingStatus
protected long	startTime
protected static java.util.Map	systemCache
protected long	timeOut
protected static edu.emory.mathcs.backport.java.util.concurrent.ExecutorService	tp
protected ChannelRenderer.Worker	worker
protected java.lang.Thread	workerThread
protected edu.emory.mathcs.backport.java.util.concurrent.Future	workTracker

Fields inherited from interface org.jasig.portal.IChannelRenderer

RCS_ID, RENDERING_FAILED, RENDERING_SUCCESSFUL, RENDERING_TIMED_OUT

Constructor Summary

ChannelRenderer(IChannel chan, ChannelRuntimeData runtimeData, edu.emory.mathcs.backport.java.util.concurrent.ExecutorService threadPool)
Default contstructor

ChannelRenderer(IChannel chan, ChannelRuntimeData runtimeData, edu.emory.mathcs.backport.java.util.concurrent.ExecutorService threadPool, SetCheckInSemaphore groupSemaphore, java.lang.Object groupRenderingKey)
Default contstructor

Method Summary

void	cancelRendering() Cancels the rendering job.
int	completeRendering() Requests renderer to complete rendering and return status.
SAX2BufferImpl	getBuffer() Returns rendered buffer.
(package private) java.util.Map	getChannelCache() Obtains a content cache specific for this channel instance.
java.lang.String	getChannelTitle() Get the dynamic channel title, if any, for the channel that this renderer has rendered.
java.lang.String	getCharacters() Returns a character output of a channel rendering.
protected void	kill() This method suppose to take care of the runaway rendering threads.
int	outputRendering(org.xml.sax.ContentHandler out) Output channel rendering through a given ContentHandler.
void	setCacheTables(java.util.Map cacheTables) Sets the cache tables for the channel renderer.
void	setChannel(IChannel channel) Sets the channel on which ChannelRenderer is to operate.
void	setCharacterCache(java.lang.String chars) Sets a character cache for the current rendering.
void	setCharacterCacheable(boolean setting) Informs IChannelRenderer that a character caching scheme will be used for the current rendering.
void	setTimeout(long value) Set the timeout value
void	startRendering() Start rendering of the channel in a new thread.
void	startRendering(SetCheckInSemaphore groupSemaphore, java.lang.Object groupRenderingKey) Starts the channel rendering process.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

log

protected final org.apache.commons.logging.Log log

DEFAULT_CACHE_CHANNELS

private static final boolean DEFAULT_CACHE_CHANNELS

Default value for CACHE_CHANNELS. This value will be used when the corresponding property cannot be loaded.

See Also:

Constant Field Values

CACHE_CHANNELS

public static final boolean CACHE_CHANNELS

renderingStatus

public static final java.lang.String[] renderingStatus

channel

protected IChannel channel

rd

protected ChannelRuntimeData rd

channelCache

protected java.util.Map channelCache

cacheTables

protected java.util.Map cacheTables

rendering

protected boolean rendering

donerendering

protected boolean donerendering

workerThread

protected java.lang.Thread workerThread

worker

protected ChannelRenderer.Worker worker

workTracker

protected edu.emory.mathcs.backport.java.util.concurrent.Future workTracker

startTime

protected long startTime

timeOut

protected long timeOut

ccacheable

protected boolean ccacheable

tp

protected static edu.emory.mathcs.backport.java.util.concurrent.ExecutorService tp

systemCache

protected static java.util.Map systemCache

groupSemaphore

protected SetCheckInSemaphore groupSemaphore

groupRenderingKey

protected java.lang.Object groupRenderingKey

Constructor Detail

ChannelRenderer

public ChannelRenderer(IChannel chan,
                       ChannelRuntimeData runtimeData,
                       edu.emory.mathcs.backport.java.util.concurrent.ExecutorService threadPool)

Default contstructor

Parameters:

chan - an IChannel value

runtimeData - a ChannelRuntimeData value

threadPool - a ThreadPool value

ChannelRenderer

public ChannelRenderer(IChannel chan,
                       ChannelRuntimeData runtimeData,
                       edu.emory.mathcs.backport.java.util.concurrent.ExecutorService threadPool,
                       SetCheckInSemaphore groupSemaphore,
                       java.lang.Object groupRenderingKey)

Default contstructor

Parameters:

chan - an IChannel value

runtimeData - a ChannelRuntimeData value

threadPool - a ThreadPool value

groupSemaphore - a SetCheckInSemaphore for the current rendering group

groupRenderingKey - an Object to be used for check ins with the group semaphore

Method Detail

setChannel

public void setChannel(IChannel channel)

Sets the channel on which ChannelRenderer is to operate.

Parameters:

channel - an IChannel

getChannelCache

java.util.Map getChannelCache()

Obtains a content cache specific for this channel instance.

Returns:

a key->rendering map for this channel

setTimeout

public void setTimeout(long value)

Set the timeout value

Specified by:

setTimeout in interface IChannelRenderer

Parameters:

value - timeout in milliseconds

setCacheTables

public void setCacheTables(java.util.Map cacheTables)

Description copied from interface: IChannelRenderer

Sets the cache tables for the channel renderer.

Specified by:

setCacheTables in interface IChannelRenderer

Parameters:

cacheTables - cache table for the channel renderer

setCharacterCacheable

public void setCharacterCacheable(boolean setting)

Informs IChannelRenderer that a character caching scheme will be used for the current rendering.

Specified by:

setCharacterCacheable in interface IChannelRenderer

Parameters:

setting - a boolean value

startRendering

public void startRendering()

Start rendering of the channel in a new thread. Note that rendered information will be accumulated in a buffer until outputRendering() function is called. startRendering() is a non-blocking function.

Specified by:

startRendering in interface IChannelRenderer

startRendering

public void startRendering(SetCheckInSemaphore groupSemaphore,
                           java.lang.Object groupRenderingKey)

Description copied from interface: IChannelRenderer

Starts the channel rendering process.

Specified by:

startRendering in interface IChannelRenderer

Parameters:

groupSemaphore - semaphore to use for a group of channels

groupRenderingKey - group rendering key

cancelRendering

public void cancelRendering()

Cancels the rendering job.

Specified by:

cancelRendering in interface IChannelRenderer

outputRendering

public int outputRendering(org.xml.sax.ContentHandler out)
                    throws java.lang.Throwable

Output channel rendering through a given ContentHandler. Note: call of outputRendering() without prior call to startRendering() is equivalent to sequential calling of startRendering() and then outputRendering(). outputRendering() is a blocking function. It will return only when the channel completes rendering or fails to render by exceeding allowed rendering time.

Specified by:

outputRendering in interface IChannelRenderer

Parameters:

out - Document Handler that will receive information rendered by the channel.

Returns:

error code. 0 - successful rendering; 1 - rendering failed; 2 - rendering timedOut;

Throws:

java.lang.Throwable - if an error occurs

completeRendering

public int completeRendering()
                      throws java.lang.Throwable

Requests renderer to complete rendering and return status. This does exactly the same things as outputRendering except for the actual stream output.

Specified by:

completeRendering in interface IChannelRenderer

Returns:

an int return status value

Throws:

java.lang.Throwable

getBuffer

public SAX2BufferImpl getBuffer()

Returns rendered buffer. This method does not perform any status checks, so make sure to call completeRendering() prior to invoking this method.

Specified by:

getBuffer in interface IChannelRenderer

Returns:

rendered buffer

getCharacters

public java.lang.String getCharacters()

Returns a character output of a channel rendering.

Specified by:

getCharacters in interface IChannelRenderer

Returns:

string representation of the channel rendering characters

setCharacterCache

public void setCharacterCache(java.lang.String chars)

Sets a character cache for the current rendering.

Specified by:

setCharacterCache in interface IChannelRenderer

Parameters:

chars - character cache for the channel renderer

kill

protected void kill()

This method suppose to take care of the runaway rendering threads. This method will be called from ChannelManager explictly.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getChannelTitle

public java.lang.String getChannelTitle()

Description copied from interface: IDynamicChannelTitleRenderer

Get the dynamic channel title, if any, for the channel that this renderer has rendered. This method must not be executed concurently with outputRendering(): the rendering framework should either first request the channel content and then requets the title, or first request the title and then request the channel content, but not both concurrently. Both this method and outputRendering() block on the channel rendering worker thread, blocking until the thread completes rendering the channel, or until the thread times out.

Specified by:

getChannelTitle in interface IDynamicChannelTitleRenderer

Returns:

String representing the dynamic channel title, or null if no dynamic channel title.