The base place manager class takes care of the necessary interactions with the place * registry to manage place registration. It handles the place-related component of chatting. It * also provides the basis for place-based access control. * *
A derived class is expected to handle initialization, cleanup and operational functionality
* via the calldown functions {@link #didInit}, {@link #didStartup}, and {@link #didShutdown} as
* well as through event listeners.
*/
public class PlaceManager
implements MessageListener, SpeakHandler.SpeakerValidator
{
/**
* An interface used to allow the registration of standard message handlers to be invoked by
* the place manager when particular types of message events are received.
*
* @deprecated Use dynamically bound methods instead. See {@link DynamicListener}.
*/
@Deprecated
public static interface MessageHandler
{
/**
* Invokes this message handler on the supplied event.
*
* @param event the message event received.
* @param pmgr the place manager for which the message is being handled.
*/
void handleEvent (MessageEvent event, PlaceManager pmgr);
}
/**
* Used to call methods on this place manager's delegates.
*/
public static abstract class DelegateOp
{
public DelegateOp (Class delegateClass) {
_delegateClass = delegateClass;
}
/** Applies an operation to the supplied delegate. */
public abstract void apply (PlaceManagerDelegate delegate);
public boolean shouldApply (PlaceManagerDelegate delegate) {
return _delegateClass.isInstance(delegate);
}
protected Class _delegateClass;
}
/** Used with {@link #updateOccupantInfo}. */
public static interface OccInfoUpdater
* OccupantInfo info = _plmgr.getOccupantInfo(bodyOid);
* // ... modifications made to 'info'
* _plmgr.updateOccupantInfo(info);
*
*/
public void updateOccupantInfo (OccupantInfo occInfo)
{
// update the canonical copy
_occInfo.put(occInfo.getBodyOid(), occInfo);
// clone the canonical copy and send an event updating the distributed set with that clone
_plobj.updateOccupantInfo((OccupantInfo)occInfo.clone());
}
/**
* Calls the supplied updater on the canonical occupant info record for the specified body
* (which must be an occupant of this place) and broadcasts the update to all other occupants.
*
* @return true if the updater was called and the update sent, false if the body could not be
* located (was not an occupant of this place).
*
* @exception ClassCastException thrown if the type of the supplied updater does not match the
* type of {@link OccupantInfo} record used for the occupant. Caveat utilitor.
*/
public null should be returned if initialization is to be
* allowed to proceed.
*/
public String checkPermissions ()
{
return null;
}
/**
* Called by the place manager after the place object has been successfully created.
*/
public void startup (PlaceObject plobj)
{
// keep track of this
_plobj = plobj;
// we usually want to create and register a speaker service instance that clients can use
// to speak in this place
if (shouldCreateSpeakService()) {
plobj.setSpeakService(_invmgr.registerDispatcher(
new SpeakDispatcher(new SpeakHandler(plobj, this))));
}
// we'll need to hear about place object events
plobj.addListener(this);
plobj.addListener(_bodyUpdater);
plobj.addListener(_occListener);
plobj.addListener(_deathListener);
// configure this place's access controller
plobj.setAccessController(getAccessController());
// let our derived classes do their thang
try {
didStartup();
} catch (Throwable t) {
log.warning("Manager choked in didStartup()", "where", where(), t);
}
// since we start empty, we need to immediately assume shutdown
checkShutdownInterval();
}
/**
* Causes the place object being managed by this place manager to be destroyed and the place
* manager to shut down.
*/
public void shutdown ()
{
// destroy the object and everything will follow from that
_omgr.destroyObject(_plobj.getOid());
// clear out our services
if (_plobj.speakService != null) {
_invmgr.clearDispatcher(_plobj.speakService);
_plobj.speakService = null;
}
// make sure we don't have any shutdowner in the queue
cancelShutdowner();
}
/**
* Provides an opportunity for the place manager to prevent bodies from entering.
*
* @return null if the body can enter, otherwise a translatable message explaining
* the reason the body is blocked from entering
*/
public String ratifyBodyEntry (BodyObject body)
{
return null;
}
/**
* Builds an {@link OccupantInfo} record for the specified body object and inserts it into our
* place object. This is called by the location services when a body enters a place. If a
* derived class wishes to perform custom actions when an occupant is being inserted into a
* room, they should override {@link #insertOccupantInfo}, if they want to react to a body
* having entered, they should override {@link #bodyEntered}.
*/
public OccupantInfo buildOccupantInfo (BodyObject body)
{
try {
// create a new occupant info instance
OccupantInfo info = body.createOccupantInfo(_plobj);
// insert the occupant info into our canonical table; this is done in a method so that
// derived classes
insertOccupantInfo(info, body);
// clone the canonical copy and insert it into the DSet
_plobj.addToOccupantInfo((OccupantInfo)info.clone());
return info;
} catch (Exception e) {
log.warning("Failure building occupant info [where=" + where() +
", body=" + body + "].", e);
return null;
}
}
/**
* Registers a particular message handler instance to be used when processing message events
* with the specified name.
*
* @param name the message name of the message events that should be handled by this handler.
* @param handler the handler to be registered.
*
* @deprecated Use dynamically bound methods instead. See {@link DynamicListener}.
*/
@Deprecated
public void registerMessageHandler (String name, MessageHandler handler)
{
// create our handler map if necessary
if (_msghandlers == null) {
_msghandlers = Maps.newHashMap();
}
_msghandlers.put(name, handler);
}
// from interface MessageListener
public void messageReceived (MessageEvent event)
{
if (_msghandlers != null) {
MessageHandler handler = _msghandlers.get(event.getName());
if (handler != null) {
handler.handleEvent(event, this);
}
}
// If the message is directed at us, see if it's a request for a method invocation
if (event.isPrivate()) { // aka if (event instanceof ServerMessageEvent)
// the first argument should be the client object of the caller or null if it is
// a server-originated event
int srcoid = event.getSourceOid();
DObject source = (srcoid <= 0) ? null : _omgr.getObject(srcoid);
Object[] args = event.getArgs(), nargs;
if (args == null) {
nargs = new Object[] { source };
} else {
nargs = new Object[args.length+1];
nargs[0] = source;
System.arraycopy(args, 0, nargs, 1, args.length);
}
// Lazily create our dispatcher now that it's actually getting a message
if (_dispatcher == null) {
Class clazz = getClass();
MethodFinder finder = _dispatcherFinders.get(clazz);
if (finder == null) {
finder = new MethodFinder(clazz);
_dispatcherFinders.put(clazz, finder);
}
_dispatcher = new DynamicListenersuper.didInit().
*/
protected void didInit ()
{
// initialize our delegates
applyToDelegates(new DelegateOp(PlaceManagerDelegate.class) {
@Override
public void apply (PlaceManagerDelegate delegate) {
delegate.didInit(_config);
}
});
}
/**
* Called if the permissions check failed, to give place managers a chance to do any cleanup
* that might be necessary due to their early initialization or permissions checking code.
*/
protected void permissionsFailed ()
{
}
/**
* @return true if we should create a speaker service for our place object so that clients can
* use it to speak in this place.
*/
protected boolean shouldCreateSpeakService ()
{
return true;
}
/**
* Creates an access controller for this place's distributed object, which by default is {@link
* CrowdObjectAccess#PLACE}.
*/
protected AccessController getAccessController ()
{
return CrowdObjectAccess.PLACE;
}
/**
* Derived classes should override this (and be sure to call super.didStartup())
* to perform any startup time initialization. The place object will be available by the time
* this method is executed.
*/
protected void didStartup ()
{
// let our delegates know that we've started up
applyToDelegates(new DelegateOp(PlaceManagerDelegate.class) {
@Override
public void apply (PlaceManagerDelegate delegate) {
delegate.didStartup(_plobj);
}
});
}
/**
* Called when this place has been destroyed and the place manager has shut down (via a call to
* {@link #shutdown}). Derived classes can override this method and perform any necessary
* shutdown time processing.
*/
protected void didShutdown ()
{
// clear out our listenership
_plobj.removeListener(this);
_plobj.removeListener(_bodyUpdater);
_plobj.removeListener(_occListener);
_plobj.removeListener(_deathListener);
// let our delegates know that we've shut down
applyToDelegates(new DelegateOp(PlaceManagerDelegate.class) {
@Override
public void apply (PlaceManagerDelegate delegate) {
delegate.didShutdown();
}
});
// if shutting down emptied the place and scheduled the shutdowner, clear that out
cancelShutdowner();
}
/**
* Called when an occupant is being added to this place. This will be before the call to {@link
* #bodyEntered} and gives the derived class a chance to set up additional information about
* the occupant that might not be tracked in the occupant info.
*/
protected void insertOccupantInfo (OccupantInfo info, BodyObject body)
{
_occInfo.put(info.getBodyOid(), info);
}
/**
* Called when a body object enters this place.
*/
protected void bodyEntered (final int bodyOid)
{
log.debug("Body entered", "where", where(), "oid", bodyOid);
// let our delegates know what's up
applyToDelegates(new DelegateOp(PlaceManagerDelegate.class) {
@Override
public void apply (PlaceManagerDelegate delegate) {
delegate.bodyEntered(bodyOid);
}
});
// if we were on the road to shutting down, step off
cancelShutdowner();
}
/**
* Called when a body object leaves this place.
*/
protected void bodyLeft (final int bodyOid)
{
log.debug("Body left", "where", where(), "oid", bodyOid);
// if their occupant info hasn't been removed (which may be the case if they logged off
// rather than left via a MoveTo request), we need to get it on out of here
Integer key = Integer.valueOf(bodyOid);
if (_plobj.occupantInfo.containsKey(key)) {
_plobj.removeFromOccupantInfo(key);
}
// clear out their canonical (local) occupant info record
OccupantInfo leaver = _occInfo.remove(bodyOid);
// let our delegates know what's up
applyToDelegates(new DelegateOp(PlaceManagerDelegate.class) {
@Override public void apply (PlaceManagerDelegate delegate) {
delegate.bodyLeft(bodyOid);
}
});
// if that leaves us with zero occupants, maybe do something
if (shouldDeclareEmpty(leaver)) {
placeBecameEmpty();
}
}
/**
* Returns whether the location should be marked as empty and potentially shutdown.
*/
protected boolean shouldDeclareEmpty (OccupantInfo leaver)
{
return (_plobj.occupants.size() == 0);
}
/**
* Called when a body's occupant info is updated.
*/
protected void bodyUpdated (final OccupantInfo info)
{
// let our delegates know what's up
applyToDelegates(new DelegateOp(PlaceManagerDelegate.class) {
@Override
public void apply (PlaceManagerDelegate delegate) {
delegate.bodyUpdated(info);
}
});
}
/**
* Called when we transition from having bodies in the place to not having any bodies in the
* place. Some places may take this as a sign to pack it in, others may wish to stick
* around. In any case, they can override this method to do their thing.
*/
protected void placeBecameEmpty ()
{
// let our delegates know what's up
applyToDelegates(new DelegateOp(PlaceManagerDelegate.class) {
@Override
public void apply (PlaceManagerDelegate delegate) {
delegate.placeBecameEmpty();
}
});
// Log.info("Place became empty " + where() + ".");
checkShutdownInterval();
}
/**
* Called on startup and when the place is empty.
*/
protected void checkShutdownInterval ()
{
// queue up a shutdown interval, unless we've already got one.
long idlePeriod = idleUnloadPeriod();
if (idlePeriod > 0L && _shutdownInterval == null) {
_shutdownInterval = new Interval(_omgr) {
@Override
public void expired () {
log.debug("Unloading idle place '" + where() + "'.");
shutdown();
}
};
_shutdownInterval.schedule(idlePeriod);
}
}
/**
* Cancels any registered shutdown interval.
*/
protected void cancelShutdowner ()
{
if (_shutdownInterval != null) {
_shutdownInterval.cancel();
_shutdownInterval = null;
}
}
/**
* Returns the period (in milliseconds) of emptiness after which this place manager will unload
* itself and shutdown. Returning 0 indicates that the place should never be
* shutdown.
*/
protected long idleUnloadPeriod ()
{
return 5 * 60 * 1000L;
}
/**
* An extensible way to add to the string representation of this class. Override this (being
* sure to call super) and append your info to the buffer.
*/
protected void toString (StringBuilder buf)
{
buf.append("place=").append(_plobj);
buf.append(", config=").append(_config);
}
/** Listens for occupant updates. */
protected SetAdapter