org.directwebremoting.impl.DefaultScriptSession Maven / Gradle / Ivy
package org.directwebremoting.impl;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import org.directwebremoting.ScriptBuffer;
import org.directwebremoting.event.ScriptSessionBindingEvent;
import org.directwebremoting.event.ScriptSessionBindingListener;
import org.directwebremoting.extend.ConverterManager;
import org.directwebremoting.extend.RealScriptSession;
import org.directwebremoting.extend.ScriptBufferUtil;
import org.directwebremoting.extend.ScriptSessionManager;
import org.directwebremoting.extend.Sleeper;
/**
* An implementation of ScriptSession and RealScriptSession.
* You should note that {@link DefaultScriptSession} and
* {@link DefaultScriptSessionManager} make calls to each other and you should
* take care not to break any constraints in inheriting from these classes.
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public class DefaultScriptSession implements RealScriptSession
{
/**
* Simple constructor
* @param id The new unique identifier for this session
* @param page The URL of the page on which we sit
* @param manager The manager that created us
* @param converterManager ...
* @param jsonOutput ...
*/
protected DefaultScriptSession(String id, ScriptSessionManager manager, String page, ConverterManager converterManager, boolean jsonOutput)
{
this.id = id;
if (id == null)
{
throw new IllegalArgumentException("id can not be null");
}
this.manager = manager;
this.page = page;
this.converterManager = converterManager;
this.jsonOutput = jsonOutput;
this.creationTime = System.currentTimeMillis();
this.lastAccessedTime = creationTime;
}
public Object getAttribute(String name)
{
invalidateIfNeeded();
return attributes.get(name);
}
public void setAttribute(String name, Object value)
{
invalidateIfNeeded();
if (value != null)
{
if (value instanceof ScriptSessionBindingListener)
{
ScriptSessionBindingListener listener = (ScriptSessionBindingListener) value;
listener.valueBound(new ScriptSessionBindingEvent(this, name));
}
attributes.put(name, value);
}
else
{
removeAttribute(name);
}
}
public void removeAttribute(String name)
{
invalidateIfNeeded();
Object value = attributes.remove(name);
if (value != null && value instanceof ScriptSessionBindingListener)
{
ScriptSessionBindingListener listener = (ScriptSessionBindingListener) value;
listener.valueUnbound(new ScriptSessionBindingEvent(this, name));
}
}
public Iterator getAttributeNames()
{
invalidateIfNeeded();
Set keys = Collections.unmodifiableSet(new HashSet(attributes.keySet()));
return keys.iterator();
}
public void invalidate()
{
invalidated = true;
// attributes is a concurrent map and can be safely iterated.
for (Map.Entry entry : attributes.entrySet())
{
Object value = entry.getValue();
if (value instanceof ScriptSessionBindingListener)
{
ScriptSessionBindingListener listener = (ScriptSessionBindingListener) value;
listener.valueUnbound(new ScriptSessionBindingEvent(this, entry.getKey()));
}
}
if (manager instanceof DefaultScriptSessionManager)
{
((DefaultScriptSessionManager) manager).invalidate(this);
}
}
public boolean isInvalidated()
{
return invalidated;
}
public String getId()
{
return id;
}
public long getCreationTime()
{
invalidateIfNeeded();
return creationTime;
}
public long getLastAccessedTime()
{
// For many accesses here we check to see if we should invalidate
// ourselves, but getLastAccessedTime() is used as part of the process
// that DefaultScriptSessionManager goes through in order to check
// everything for validity. So if we do this check here then DSSM will
// give a ConcurrentModificationException if anything does timeout
// checkNotInvalidated();
return lastAccessedTime;
}
public void addScript(ScriptBuffer script)
{
invalidateIfNeeded();
if (script == null)
{
throw new NullPointerException("null script");
}
synchronized (this.scripts)
{
scripts.add(ScriptBufferUtil.createOutput(script, converterManager, jsonOutput));
}
synchronized (sleeperLock)
{
if (sleeper != null) {
sleeper.wakeUpForData();
}
}
}
public void addRunnable(final Runnable runnable)
{
invalidateIfNeeded();
if (runnable == null)
{
throw new NullPointerException("null runnable");
}
synchronized (this.scripts)
{
scripts.add(runnable);
}
synchronized (sleeperLock)
{
if (sleeper != null) {
sleeper.wakeUpForData();
}
}
}
public void setSleeper(Sleeper sleeper)
{
invalidateIfNeeded();
synchronized (sleeperLock)
{
this.sleeper = sleeper;
}
}
@SuppressWarnings("hiding")
public void clearSleeper(Sleeper sleeper)
{
invalidateIfNeeded();
synchronized (sleeperLock)
{
if (this.sleeper == sleeper)
{
this.sleeper = null;
}
}
}
public Script getScript(long scriptIndex)
{
synchronized (scripts)
{
if (scriptsOffset < 0)
{
throw new IllegalStateException("Confirmed script index must be set before accessing scripts.");
}
int listIndex = (int) (scriptIndex - scriptsOffset);
if (listIndex < 0)
{
listIndex = 0;
}
if (listIndex < scripts.size()) {
final Object script = scripts.get(listIndex);
final long resultingScriptIndex = scriptsOffset + listIndex;
return new Script()
{
public long getIndex()
{
return resultingScriptIndex;
}
public Object getScript()
{
return script;
}
};
} else {
return null;
}
}
}
/* (non-Javadoc)
* @see org.directwebremoting.extend.RealScriptSession#confirmTransfer(long)
*/
public void confirmScripts(long confirmedScriptIndex)
{
long nextScriptIndex = confirmedScriptIndex + 1;
synchronized (scripts)
{
// If this is a re-born script session with uninitialized script offset, or
// client's offset is outside our range for other reasons, then just
// fast-forward ourselves to the client's offset so it will continue
// receiving an unbroken series of scripts
if (scriptsOffset < 0 || nextScriptIndex > scriptsOffset + scripts.size())
{
scriptsOffset = nextScriptIndex;
}
// Purge confirmed
long remove = nextScriptIndex - scriptsOffset; // if we are on offset 10 and 10 is confirmed, we should remove 1
if (remove > 0) {
for(long i=0; i manager.getScriptSessionTimeout())
{
synchronized (sleeperLock) {
if (connectionValidationTime > 0 && now < connectionValidationTime) {
// We are waiting for an already started connection validation so do nothing
return;
} else if (connectionValidationTime == 0 && sleeper != null) {
// Start a connection validation by closing the current poll
int disconnectedTime = sleeper.wakeUpToClose();
connectionValidationTime = now + disconnectedTime + connectionValidationTimeout;
return;
}
}
// No ongoing connection validation and no connection (sleeper) so this is
// the end of the road
invalidate();
}
}
/**
* Set the time to wait for client to poll when asking for connection validation.
* @param connectionValidationTimeout ..
*/
public void setConnectionValidationTimeout(int connectionValidationTimeout)
{
this.connectionValidationTimeout = connectionValidationTimeout;
}
@Override
public int hashCode()
{
return 572 + id.hashCode();
}
@Override
public boolean equals(Object obj)
{
if (obj == null)
{
return false;
}
if (obj == this)
{
return true;
}
if (!this.getClass().equals(obj.getClass()))
{
return false;
}
DefaultScriptSession that = (DefaultScriptSession) obj;
return this.id.equals(that.id);
}
@Override
public String toString()
{
return "DefaultScriptSession[id=" + getDebugName() + "]";
}
/**
* A very short name for debugging purposes
* @return ...
*/
protected String getDebugName()
{
int slashPos = id.indexOf('/');
return id.substring(0, 4) + (slashPos >= 0 ? id.substring(slashPos, slashPos+5) : "");
}
/**
* How we convert parameters
*/
protected ConverterManager converterManager = null;
/**
* Are we outputting in JSON mode?
*/
protected boolean jsonOutput = false;
/**
* The server side attributes for this page.
* GuardedBy("attributes")
*/
protected final Map attributes = new ConcurrentHashMap();
/**
* When the the web page that we represent last contact us using DWR?
*/
private volatile long lastAccessedTime = 0L;
/**
* When > 0 we are waiting for the client until the set time to validate the connection by polling again
*/
private volatile long connectionValidationTime = 0;
/**
* How long to wait for a client to poll when asking for connection validation
*/
private int connectionValidationTimeout = 10000;
/**
* Have we been made invalid?
*/
private volatile boolean invalidated = false;
/**
* The sleeper that waits for new data.
*/
protected Sleeper sleeper = null;
/**
* The lock for synchronizing sleepers access.
*/
protected Object sleeperLock = new Object();
/**
* The script index of the first item in the scripts collection.
*/
protected long scriptsOffset = 0;
/**
* The list of waiting scripts (String or Runnable).
* GuardedBy("self") for iteration and compound actions.
*/
protected final LinkedList