com.threerings.presents.server.PresentsSession Maven / Gradle / Ivy
//
// $Id$
//
// Narya library - tools for developing networked games
// Copyright (C) 2002-2012 Three Rings Design, Inc., All Rights Reserved
// http://code.google.com/p/narya/
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation; either version 2.1 of the License, or
// (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package com.threerings.presents.server;
import java.net.InetAddress;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.TimeZone;
import java.io.IOException;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import com.google.inject.Inject;
import com.samskivert.util.IntMap;
import com.samskivert.util.IntMaps;
import com.samskivert.util.ResultListener;
import com.samskivert.util.Throttle;
import com.threerings.util.Name;
import com.threerings.presents.annotation.AnyThread;
import com.threerings.presents.annotation.EventThread;
import com.threerings.presents.client.Client;
import com.threerings.presents.data.ClientObject;
import com.threerings.presents.dobj.DEvent;
import com.threerings.presents.dobj.DObject;
import com.threerings.presents.dobj.ObjectAccessException;
import com.threerings.presents.dobj.ObjectDestroyedEvent;
import com.threerings.presents.dobj.ProxySubscriber;
import com.threerings.presents.net.AuthRequest;
import com.threerings.presents.net.BootstrapData;
import com.threerings.presents.net.BootstrapNotification;
import com.threerings.presents.net.CompoundDownstreamMessage;
import com.threerings.presents.net.CompoundUpstreamMessage;
import com.threerings.presents.net.Credentials;
import com.threerings.presents.net.DownstreamMessage;
import com.threerings.presents.net.EventNotification;
import com.threerings.presents.net.FailureResponse;
import com.threerings.presents.net.ForwardEventRequest;
import com.threerings.presents.net.LogoffRequest;
import com.threerings.presents.net.Message;
import com.threerings.presents.net.ObjectResponse;
import com.threerings.presents.net.PingRequest;
import com.threerings.presents.net.PongResponse;
import com.threerings.presents.net.SubscribeRequest;
import com.threerings.presents.net.ThrottleUpdatedMessage;
import com.threerings.presents.net.TransmitDatagramsRequest;
import com.threerings.presents.net.UnsubscribeRequest;
import com.threerings.presents.net.UnsubscribeResponse;
import com.threerings.presents.net.UpdateThrottleMessage;
import com.threerings.presents.net.UpstreamMessage;
import com.threerings.presents.server.net.PresentsConnection;
import com.threerings.nio.conman.Connection;
import com.threerings.nio.conman.ConnectionManager;
import static com.threerings.presents.Log.log;
/**
* Represents a client session in the server. It is associated with a connection instance (while
* the client is connected) and acts as the intermediary for the remote client in terms of passing
* along events forwarded by the client, ensuring that subscriptions are maintained on behalf of
* the client and that events are forwarded to the client.
*
* A note on synchronization: the client object is structured so that its
* Subscriber implementation (which is called from the dobjmgr thread) can proceed
* without synchronization. This does not overlap with its other client duties which are called
* from the conmgr thread and therefore also need not be synchronized.
*/
public class PresentsSession
implements PresentsConnection.MessageHandler, ClientResolutionListener
{
/** Used by {@link PresentsSession#setUsername} to report success or failure. */
public static interface UserChangeListener
{
/** Called when the new client object has been resolved and the new client object reported
* to the client, but the old one has not yet been destroyed. Any events delivered on this
* callback to the old client object will be delivered.
*
* @param rl when this method is finished with its business and the old client object can
* be destroyed, the result listener should be called. */
void changeReported (ClientObject newObji, ResultListener rl);
/** Called when the user change is completed, the old client object is destroyed and all
* updates are committed. */
void changeCompleted (ClientObject newObj);
/** Called if some failure occurs during the user change process. */
void changeFailed (Exception cause);
}
/**
* Returns the credentials used to authenticate this session.
*/
public Credentials getCredentials ()
{
return _areq.getCredentials();
}
/**
* Returns the time zone in which the client is operating.
*/
public TimeZone getTimeZone ()
{
return _areq.getTimeZone();
}
/**
* Returns the shared secret for this session.
*/
public byte[] getSecret ()
{
return (_areq == null) ? null : _areq.getSecret();
}
/**
* Returns true if this session has been disconnected for sufficiently long that it should be
* forcibly ended.
*/
public boolean checkExpired (long now)
{
return (getConnection() == null && (now - _networkStamp > getFlushTime()));
}
/**
* Returns the time at which this client started their network session.
*/
public long getSessionStamp ()
{
return _sessionStamp;
}
/**
* Returns the time at which this client most recently connected or disconnected.
*/
public long getNetworkStamp ()
{
return _networkStamp;
}
/**
* Returns the username with which this client authenticated. Note: if {@link #setUsername} has
* been called this may differ from {@link #getClientObject}.username.
*/
public Name getAuthName ()
{
return _authname;
}
/**
* Returns the address of the connected client or null if this client is not connected.
*/
public InetAddress getInetAddress ()
{
Connection conn = getConnection();
return (conn == null) ? null : conn.getInetAddress();
}
/**
* Checks whether the client has requested that datagram transmission be enabled.
*/
public boolean getTransmitDatagrams ()
{
PresentsConnection conn = getConnection();
return conn != null && conn.getTransmitDatagrams();
}
/**
* Configures this session with a custom class loader that will be used when unserializing
* classes from the network.
*/
public void setClassLoader (ClassLoader loader)
{
_loader = loader;
PresentsConnection conn = getConnection();
if (conn != null) {
conn.setClassLoader(loader);
}
}
/**
* Configures the rate at which incoming messages are throttled for this client. This will
* communicate the new limit to the client and begin enforcing the limit when the client has
* acknowledged the new limit.
*
* Note: this means that a hacked client can refuse to ACK message rate reductions
* and continue to use the most generous rate ever assigned to it. Don't increase the throttle
* beyond the default for untrusted clients. This mechanism exists so that trusted clients can
* have their throttle relaxed in a robust manner which will not result in disconnects if the
* client happens to be at or near the throttle limit when the throttle is reduced.
*/
@EventThread
public void setIncomingMessageThrottle (int messagesPerSec)
{
// store and post update immediately if connected
_messagesPerSec = messagesPerSec;
if (getConnection() != null) {
sendThrottleUpdate();
}
}
/**
* Danger: this method is not for general consumption. This changes the username of
* the client, but should only be done very early in a user's session, when you know that no
* one has mapped the user based on their username or has in any other way made use of their
* username in a way that will break. However, it should not be done too early in the
* session. The client must be fully resolved.
*
*
It exists to support systems wherein a user logs in with an account username and then
* chooses a "screen name" by which they will play (often from a small set of available
* "characters" available per account). This will take care of remapping the username to client
* object mappings that were made by the Presents services when the user logs on, but anything
* else that has had its grubby mits on the username will be left to its own devices, hence the
* care that must be exercised when using this method.
*
* @param ucl an entity that will (optionally) be notified when the username conversion process
* is complete.
*/
public void setUsername (Name username, final UserChangeListener ucl)
{
ClientResolutionListener clr = new ClientResolutionListener() {
public void clientResolved (final Name username, final ClientObject clobj) {
// if they old client object is gone by now, they ended their session while we were
// switching, so freak out
if (_clobj == null) {
log.warning("Client disappeared before we could complete the switch to a " +
"new client object", "ousername", clobj.username,
"nusername", username);
_clmgr.releaseClientObject(username);
Exception error = new Exception("Early withdrawal");
resolutionFailed(username, error);
return;
}
// call down to any derived classes
clientObjectWillChange(_clobj, clobj);
// let the caller know that we've got some new business
if (ucl != null) {
ucl.changeReported(clobj, new ResultListener() {
public void requestCompleted (Void result) {
finishResolved(username, clobj);
}
public void requestFailed (Exception cause) {
finishResolved(username, clobj);
}
});
} else {
finishResolved(username, clobj);
}
}
/**
* Finish the final phase of the switch.
*/
protected void finishResolved (Name username, ClientObject clobj) {
// let the client know that the rug has been yanked out from under their ass
Object[] args = new Object[] { clobj.getOid() };
_clobj.postMessage(ClientObject.CLOBJ_CHANGED, args);
// release our old client object; this will destroy it
_clmgr.releaseClientObject(_clobj.username);
// update our internal fields
_clobj = clobj;
// call down to any derived classes
clientObjectDidChange(_clobj);
// let our listener know we're groovy
if (ucl != null) {
ucl.changeCompleted(_clobj);
}
}
public void resolutionFailed (Name username, Exception reason) {
Name oldName = (_clobj == null) ? null : _clobj.username;
log.warning("Unable to resolve new client object",
"oldname", oldName, "newname", username, "reason", reason, reason);
// let our listener know we're hosed
if (ucl != null) {
ucl.changeFailed(reason);
}
}
};
// resolve the new client object
_clmgr.resolveClientObject(username, clr);
}
/**
* Double Danger: this method is not for general consumption. Like
* {@code #setUsername}, this changes the username of the client, but unlike setUsername, it
* does it in the existing client object. Care must be taken to ensure that any client or
* server code either doesn't map things based on username before this call, or that it's
* updated to reflect the change.
*
* @return - true if the client was successfully renamed, false otherwise
*/
public boolean updateUsername (Name username)
{
return _clmgr.renameClientObject(_clobj.username, username);
}
/**
* returns the client object that is associated with this client.
*/
public ClientObject getClientObject ()
{
return _clobj;
}
/**
* Forcibly terminates a client's session. This must be called from the dobjmgr thread.
*/
@EventThread
public void endSession ()
{
_clmgr.clientSessionWillEnd(this);
// queue up a request for our connection to be closed (if we have a connection, that is)
Connection conn = getConnection();
if (conn != null) {
// go ahead and clear out our connection now to prevent funniness
setConnection(null);
// have the connection manager close our connection when it is next convenient
_conmgr.closeConnection(conn);
}
// if we don't have a client object, we failed to resolve in the first place, in which case
// we have to cope as best we can
if (_clobj != null) {
// and clean up after ourselves
try {
sessionDidEnd();
} catch (Exception e) {
log.warning("Choked in sessionDidEnd " + this + ".", e);
}
// release (and destroy) our client object
_clmgr.releaseClientObject(_clobj.username);
// we only report that our session started if we managed to resolve our client object,
// so we only report that it ended in the same circumstance
_clmgr.clientSessionDidEnd(this);
}
// we always want to clear ourselves out of the client manager
_clmgr.clearSession(this);
// clear out the client object so that we know the session is over
_clobj = null;
}
/**
* This is called when the server is shut down in the middle of a client session. In this
* circumstance, {@link #endSession} will not be called and so any persistent data
* that might normally be flushed at the end of a client's session should likely be flushed
* here.
*/
public void shutdown ()
{
// if the client is connected, we need to fake the computation of their final connect time
// because we won't be closing their socket normally
if (getConnection() != null) {
long now = System.currentTimeMillis();
_connectTime += ((now - _networkStamp) / 1000);
}
}
// from interface ClientResolutionListener
public void clientResolved (Name username, ClientObject clobj)
{
// we'll be keeping this bad boy
_clobj = clobj;
// if our connection was closed while we were resolving our client object, then just
// abandon ship
if (getConnection() == null) {
log.info("Session ended before client object could be resolved " + this + ".");
endSession();
return;
}
// Dump our secret into the client local for easy access
clobj.getLocal(ClientLocal.class).secret = getSecret();
// finish up our regular business
sessionWillStart();
sendBootstrap();
// let the client manager know that we're operational
_clmgr.clientSessionDidStart(this);
}
// from interface ClientResolutionListener
public void resolutionFailed (Name username, Exception reason)
{
if (reason instanceof ClientResolver.ClientDisconnectedException) {
log.info("Client disconnected during resolution", "who", who());
} else {
// urk; nothing to do but complain and get the f**k out of dodge
log.warning("Unable to resolve client", "who", who(), reason);
}
// end the session now to prevent danglage
endSession();
}
// from interface Connection.MessageHandler
public void handleMessage (Message message)
{
// if the client has been getting crazy with the cheeze whiz, stick a fork in them; the
// first time through we end our session, subsequently _throttle is null and we just drop
// any messages that come in until we've fully shutdown
if (_throttle == null) {
// log.info("Dropping message from force-quit client", "conn", getConnection(),
// "msg", message);
return;
} else if (_throttle.throttleOp(message.received)) {
handleThrottleExceeded();
}
dispatchMessage(message);
}
/**
* Processes a message without throttling.
*/
protected void dispatchMessage (Message message)
{
_messagesIn++; // count 'em up!
// we dispatch to a message dispatcher that is specialized for the particular class of
// message that we received
MessageDispatcher disp = _disps.get(message.getClass());
if (disp == null) {
log.warning("No dispatcher for message", "msg", message);
return;
}
// otherwise pass the message on to the dispatcher
disp.dispatch(this, message);
}
/**
* Called when {@link #setUsername} has been called and the new client object is about to be
* applied to this client. The old client object will not yet have been destroyed, so any final
* events can be sent along prior to the new object being put into effect.
*/
protected void clientObjectWillChange (ClientObject oldClobj, ClientObject newClobj)
{
}
/**
* Called after the new client object has been committed to this client due to a call to {@link
* #setUsername}.
*/
protected void clientObjectDidChange (ClientObject newClobj)
{
}
/**
* Initializes this client instance with the specified username, connection instance and
* client object and begins a client session.
*/
protected void startSession (Name authname, AuthRequest req, PresentsConnection conn,
Object authdata)
{
_authname = authname;
_areq = req;
_authdata = authdata;
setConnection(conn);
// resolve our client object before we get fully underway
_clmgr.resolveClientObject(_authname, this);
// make a note of our session start time
_sessionStamp = System.currentTimeMillis();
}
/**
* Called by the client manager when a new connection arrives that authenticates as this
* already established client. This must only be called from the congmr thread.
*/
protected void resumeSession (AuthRequest req, PresentsConnection conn)
{
// check to see if we've already got a connection object, in which case it's probably stale
Connection oldconn = getConnection();
if (oldconn != null && !oldconn.isClosed()) {
log.info("Closing stale connection", "old", oldconn, "new", conn);
// close the old connection (which results in everything being properly unregistered)
oldconn.close();
}
// note our new auth request (so that we can deliver the proper bootstrap services)
_areq = req;
// start using the new connection
setConnection(conn);
// if a client connects, drops the connection and reconnects within the span of a very
// short period of time, we'll find ourselves in resumeSession() before their client object
// was resolved from the initial connection; in such a case, we can simply bail out here
// and let the original session establishment code take care of initializing this resumed
// session
if (_clobj == null) {
log.info("Rapid-fire reconnect caused us to arrive in resumeSession() before the " +
"original session resolved its client object " + this + ".");
return;
}
// we need to get onto the dobj thread so that we can finalize resumption of the session
_omgr.postRunnable(new Runnable() {
public void run () {
// now that we're on the dobjmgr thread we can resume our session resumption
finishResumeSession();
}
});
}
/**
* This is called from the dobjmgr thread to complete the session resumption. We call some call
* backs and send the bootstrap info to the client.
*/
@EventThread
protected void finishResumeSession ()
{
// if we have no client object for whatever reason; we're hosed, shut ourselves down
if (_clobj == null) {
log.info("Missing client object for resuming session " + this + ".");
endSession();
return;
}
// make extra sure we have no lingering subscriptions
clearSubscrips(false);
// Update our client secret with the new auth request
_clobj.getLocal(ClientLocal.class).secret = getSecret();
// let derived classes do any session resuming
sessionWillResume();
// send off a bootstrap notification immediately as we've already got our client object
sendBootstrap();
// resend the throttle update if non-default
if (_messagesPerSec != Client.DEFAULT_MSGS_PER_SECOND) {
sendThrottleUpdate();
}
log.info("Session resumed " + this + ".");
}
/**
* Sends the throttle update to the client.
*/
protected void sendThrottleUpdate ()
{
synchronized(_pendingThrottles) {
_pendingThrottles.add(_messagesPerSec);
}
postMessage(new UpdateThrottleMessage(_messagesPerSec), null);
// when we get a ThrottleUpdatedMessage from the client, we'll apply the new throttle
}
/**
* Queues up a runnable on the object manager thread where we can safely end the session.
*/
@AnyThread
protected void safeEndSession ()
{
if (!_omgr.isRunning()) {
log.info("Dropping end session request as we're shutting down " + this + ".");
} else {
_omgr.postRunnable(new Runnable() {
public void run () {
endSession();
}
});
}
}
/**
* Creates our incoming message throttle. Use {@link #setIncomingMessageThrottle} to adjust the
* throttle for running clients.
*/
protected Throttle createIncomingMessageThrottle ()
{
// see throttleUpdated() for details on these numbers
return new Throttle(10*(Client.DEFAULT_MSGS_PER_SECOND+1), 10*1000L);
}
/**
* Called when a client exceeds their allotted incoming messages per second throttle.
*/
protected void handleThrottleExceeded ()
{
log.warning("Client exceeded incoming message throttle, disconnecting",
"client", this, "throttle", _throttle);
safeEndSession();
_throttle = null;
}
/**
* Makes a note that this client is no longer subscribed to this object. The subscription map
* is used to clean up after the client when it goes away.
*/
protected synchronized void unmapSubscrip (int oid)
{
ClientProxy rec;
synchronized (_subscrips) {
rec = _subscrips.remove(oid);
}
if (rec != null) {
rec.unsubscribe();
} else {
boolean alreadyDestroyed = _destroyedSubs.remove(oid);
if (!alreadyDestroyed) {
log.warning("Missing subscription in unmap", "client", this, "oid", oid);
}
}
}
/**
* Clears out the tracked client subscriptions. Called when the client goes away and shouldn't
* be called otherwise.
*/
protected void clearSubscrips (boolean verbose)
{
for (ClientProxy rec : _subscrips.values()) {
if (verbose) {
log.info("Clearing subscription", "client", this, "obj", rec.object.getOid());
}
rec.unsubscribe();
}
_subscrips.clear();
}
/**
* Called when the client session is first started. The client object has been created at this
* point and after this method is executed, the bootstrap information will be sent to the
* client which will trigger the start of the session. Derived classes that override this
* method should be sure to call super.sessionWillStart.
*
* Note: This function will be called on the dobjmgr thread which means that object
* manipulations are OK, but client instance manipulations must done carefully.
*/
@EventThread
protected void sessionWillStart ()
{
// configure a specific access controller for the client object
_clobj.setAccessController(PresentsObjectAccess.CLIENT);
}
/**
* Called when the client resumes a session (after having disconnected and reconnected). After
* this method is executed, the bootstrap information will be sent to the client which will
* trigger the resumption of the session. Derived classes that override this method should be
* sure to call super.sessionWillResume.
*
*
Note: This function will be called on the dobjmgr thread which means that object
* manipulations are OK, but client instance manipulations must done carefully.
*/
@EventThread
protected void sessionWillResume ()
{
}
/**
* Called when the client session ends (either because the client logged off or because the
* server forcibly terminated the session). Derived classes that override this method should
* be sure to call super.sessionDidEnd.
*
*
Note: This function will be called on the dobjmgr thread which means that object
* manipulations are OK, but client instance manipulations must done carefully.
*/
@EventThread
protected void sessionDidEnd ()
{
// clear out our subscriptions so that we don't get a complaint about inability to forward
// the object destroyed event we're about to generate
clearSubscrips(false);
}
/**
* Called to inform derived classes when the client has subscribed to a distributed object.
*/
@EventThread
protected void subscribedToObject (DObject object)
{
}
/**
* Called to inform derived classes when the client has unsubscribed from a distributed object.
*/
@EventThread
protected void unsubscribedFromObject (DObject object)
{
}
/**
* This is called once we have a handle on the client distributed object. It sends a bootstrap
* notification to the client with all the information it will need to interact with the
* server.
*/
protected void sendBootstrap ()
{
// log.info("Sending bootstrap " + this + ".");
// create and populate our bootstrap data
BootstrapData data = createBootstrapData();
populateBootstrapData(data);
// create a send bootstrap notification
postMessage(new BootstrapNotification(data), null);
}
/**
* Derived client classes can override this member to create derived bootstrap data classes
* that contain extra bootstrap information, if desired.
*/
protected BootstrapData createBootstrapData ()
{
return new BootstrapData();
}
/**
* Derived client classes can override this member to populate the bootstrap data with
* additional information. They should be sure to call super.populateBootstrapData
* before doing their own populating, however.
*
*
Note: This function will be called on the dobjmgr thread which means that object
* manipulations are OK, but client instance manipulations must be done carefully.
*/
protected void populateBootstrapData (BootstrapData data)
{
// give them the connection id
Connection conn = getConnection();
if (conn != null) {
data.connectionId = conn.getConnectionId();
} else {
log.warning("Connection disappeared before we could send bootstrap response.",
"client", this);
return; // stop here as we're just going to throw away this bootstrap
}
// and the client object id
data.clientOid = _clobj.getOid();
// fill in the list of bootstrap services
if (_areq.getBootGroups() == null) {
log.warning("Client provided no invocation service boot groups? " + this);
data.services = Lists.newArrayList();
} else {
data.services = _invmgr.getBootstrapServices(_areq.getBootGroups());
}
}
/**
* Called by the connection manager when this client's connection is unmapped. That may be
* because of a connection failure (in which case this call will be followed up by a call to
* connectionFailed) or it may be because of an orderly closing of the
* connection. In either case, the client can deal with its lack of a connection in this
* method. This is invoked by the conmgr thread and should behave accordingly.
*/
protected void wasUnmapped ()
{
// clear out our connection reference
setConnection(null);
// reset the throttle state in case the client reconnects
_throttle = createIncomingMessageThrottle();
synchronized (_pendingThrottles) {
_pendingThrottles.clear();
}
// if we are being closed after the omgr has shutdown, then just stop here; the whole world
// is about to come to a screeching halt anyway
if (_omgr.isRunning()) {
// clear out our subscriptions: we need to do this on the dobjmgr thread. it is
// important that we do this *after* we clear out our connection reference. once the
// connection ref is null, no more subscriptions will be processed (even those that
// were queued up before the connection went away)
_omgr.postRunnable(new Runnable() {
public void run () {
sessionConnectionClosed();
}
});
}
}
/**
* Called on the dobjmgr thread when the connection associated with this session has been
* closed and unmapped. If the user logged off before closing their connection, this will be
* preceded by a call to {@link #sessionDidEnd}.
*/
@EventThread
protected void sessionConnectionClosed ()
{
// clear out our dobj subscriptions in case they weren't cleared by a call to sessionDidEnd
clearSubscrips(false);
}
/**
* Called by the connection manager when this client's connection fails. This is invoked on the
* conmgr thread and should behave accordingly.
*/
protected void connectionFailed (IOException fault)
{
// nothing to do here, the client manager already complained about the failed connection
}
/**
* Sets our connection reference in a thread safe way. Also establishes the back reference to
* us as the connection's message handler.
*/
protected synchronized void setConnection (PresentsConnection conn)
{
long now = System.currentTimeMillis();
if (_conn != null) {
// if our connection is being cleared out, record the amount of time we were connected
// to our total connected time
if (conn == null) {
_connectTime += ((now - _networkStamp) / 1000);
_messagesDropped = 0;
}
// make damn sure we don't get any more messages from the old connection
_conn.clearMessageHandler();
}
// keep a handle to the new connection
_conn = conn;
// if we're setting a connection rather than clearing one out...
if (_conn != null) {
// tell the connection to pass messages on to us
_conn.setMessageHandler(this);
// configure any active custom class loader
if (_loader != null) {
_conn.setClassLoader(_loader);
}
}
// make a note that our network status changed
_networkStamp = now;
}
/**
* The connection instance must be accessed via this member function because it is read from
* both the dobjmgr and conmgr threads and is modified by the conmgr thread.
*
* @return The connection instance associated with this client or null if the client is not
* currently connected.
*/
protected synchronized PresentsConnection getConnection ()
{
return _conn;
}
/**
* Callable from non-dobjmgr thread, this queues up a runnable on the dobjmgr thread to post
* the supplied message to this client.
*/
protected final void safePostMessage (DownstreamMessage msg)
{
safePostMessage(msg, null);
}
/**
* Callable from non-dobjmgr thread, this queues up a runnable on the dobjmgr thread to post
* the supplied message to this client.
*/
protected final void safePostMessage (
final DownstreamMessage msg, final PresentsConnection expect)
{
_omgr.postRunnable(new Runnable() {
public void run () {
postMessage(msg, expect);
}
});
}
/**
* Collects downstream messages in a compound message until finishCompoundMessage is called.
*/
protected void startCompoundMessage ()
{
if (_compound == null) {
_compound = new CompoundDownstreamMessage();
}
_compoundDepth++;
}
/**
* Sends the compound message created in startCompoundMessage.
*/
protected void finishCompoundMessage ()
{
if (--_compoundDepth == 0) {
CompoundDownstreamMessage downstream = _compound;
_compound = null;
if (!downstream.msgs.isEmpty()) {
postMessage(downstream, null);
}
}
}
/** Queues a message for delivery to the client. */
protected boolean postMessage (DownstreamMessage msg, PresentsConnection expect)
{
PresentsConnection conn = getConnection();
// make sure that the connection they expect us to be using is the one we're using; there
// are circumstances were sufficient delay between request and response gives the client
// time to drop their original connection and establish a new one, opening the door to
// major confusion
if (expect != null && conn != expect) {
return false;
}
if (_compound != null) {
_compound.msgs.add(msg);
return true;
}
// make sure we have a connection at all
if (conn != null) {
conn.postMessage(msg);
_messagesOut++; // count 'em up!
return true;
}
// don't log dropped messages unless we're dropping a lot of them (meaning something is
// still queueing messages up for this dead client even though it shouldn't be)
if (++_messagesDropped % 50 == 0) {
log.warning("Dropping many messages?", "client", this,
"count", _messagesDropped, "msg", msg);
}
// make darned sure we don't have any remaining subscriptions
if (_subscrips.size() > 0) {
// log.warning("Clearing stale subscriptions", "client", this,
// "subscrips", _subscrips.size());
clearSubscrips(_messagesDropped > 10);
}
return false;
}
/**
* Notifies this client that its throttle was updated.
*/
protected void throttleUpdated ()
{
int messagesPerSec;
synchronized(_pendingThrottles) {
if (_pendingThrottles.size() == 0) {
log.warning("Received throttleUpdated but have no pending throttles",
"client", this);
return;
}
messagesPerSec = _pendingThrottles.remove(0);
}
// log.info("Applying updated throttle", "client", this, "msgsPerSec", messagesPerSec);
// We set our hard throttle over a 10 second period instead of a 1 second period to
// account for periods of network congestion that might cause otherwise properly
// throttled messages to bunch up while they're "on the wire"; we also add a one
// message buffer so that if the client is right up against the limit, we don't end
// up quibbling over a couple of milliseconds
_throttle.reinit(10*messagesPerSec+1, 10*1000L);
}
@Override
public String toString ()
{
StringBuilder buf = new StringBuilder("[");
toString(buf);
return buf.append("]").toString();
}
protected String who ()
{
return (_authname == null) ? "null" :
(_authname.getClass().getSimpleName() + "(" + _authname + ")");
}
/**
* Returns the duration (in milliseconds) after which a disconnected session will be terminated
* and flushed.
*/
protected long getFlushTime ()
{
return DEFAULT_FLUSH_TIME;
}
/**
* Derived classes override this to augment stringification.
*/
protected void toString (StringBuilder buf)
{
buf.append("who=").append(who());
buf.append(", conn=").append(getConnection());
buf.append(", in=").append(_messagesIn);
buf.append(", out=").append(_messagesOut);
}
/**
* Creates a properly initialized inner-class proxy subscriber.
*/
protected ClientProxy createProxySubscriber ()
{
return new ClientProxy();
}
/** Used to track information about an object subscription. */
protected class ClientProxy implements ProxySubscriber
{
public DObject object;
public void unsubscribe ()
{
object.removeSubscriber(this);
unsubscribedFromObject(object);
}
// from interface ProxySubscriber
public void objectAvailable (DObject dobj)
{
if (postMessage(new ObjectResponse(dobj), _oconn)) {
_firstEventId = _omgr.getNextEventId(false);
object = dobj;
ClientProxy orec;
synchronized (_subscrips) {
// make a note of this new subscription
orec = _subscrips.put(dobj.getOid(), this);
}
if (orec != null) {
log.warning("Replacing existing subscription.", "oid", dobj.getOid(),
"client", PresentsSession.this);
orec.unsubscribe();
}
subscribedToObject(dobj);
} else {
// if we failed to send the object response, unsubscribe
dobj.removeSubscriber(this);
}
}
// from interface ProxySubscriber
public void requestFailed (int oid, ObjectAccessException cause)
{
postMessage(new FailureResponse(oid, cause.getMessage()), _oconn);
}
// from interface ProxySubscriber
public void eventReceived (DEvent event)
{
if (event instanceof PresentsDObjectMgr.AccessObjectEvent) {
log.warning("Ignoring event that shouldn't be forwarded " + event + ".",
new Exception());
return;
}
// if this message was posted before we received this object and has already been
// applied, then this event has already been applied to this object and we should not
// forward it, it is equivalent to all the events applied to the object before we
// became a subscriber
if (event.eventId < _firstEventId) {
return;
}
postMessage(new EventNotification(event), _oconn);
if (event instanceof ObjectDestroyedEvent) {
// Make sure it's cleared out. Otherwise, client-server timing can
// be such that a client stays subscribed to a no-longer-managed dobj.
// NOTE: We keep the oid itself on the destroyedSubs list to validate against since
// we may get a late unsubscribe after the destruction event has gone through. Thus
// there is still potentially a memory leak until logoff of the oid, but the dobj
// itself can be collected.
ClientProxy sub;
int oid = object.getOid();
synchronized(_subscrips) {
sub = _subscrips.remove(oid);
if (sub != null) {
_destroyedSubs.add(oid);
}
}
if (sub == ClientProxy.this) {
unsubscribe();
}
}
}
// from interface ProxySubscriber
public ClientObject getClientObject ()
{
return PresentsSession.this.getClientObject();
}
protected long _firstEventId;
// the connection that was active at the time we were constructed
protected PresentsConnection _oconn = getConnection();
}
/**
* Message dispatchers are used to dispatch each different type of message. We can look the
* dispatcher up in a table and invoke it through an overloaded member which is faster (so we
* think) than doing a bunch of instanceofs.
*/
protected static interface MessageDispatcher
{
/**
* Dispatch the supplied message for the specified client.
*/
void dispatch (PresentsSession client, Message mge);
}
/**
* Processes subscribe requests.
*/
protected static class SubscribeDispatcher implements MessageDispatcher
{
public void dispatch (PresentsSession client, Message msg)
{
SubscribeRequest req = (SubscribeRequest)msg;
// log.info("Subscribing", "client", client, "oid", req.getOid());
// forward the subscribe request to the omgr for processing
client._omgr.subscribeToObject(req.getOid(), client.createProxySubscriber());
}
}
/**
* Processes compound messages.
*/
protected static class CompoundDispatcher implements MessageDispatcher
{
public void dispatch (final PresentsSession client, Message msg)
{
// Compound downstream messages sent while dispatching the upstream compound message
client._omgr.postRunnable(new Runnable() {
public void run () {
client.startCompoundMessage();
}});
for (UpstreamMessage submsg : ((CompoundUpstreamMessage)msg).msgs) {
client.dispatchMessage(submsg);
}
// Send any messages produced en masse now that we've finished dispatching
client._omgr.postRunnable(new Runnable() {
public void run () {
client.finishCompoundMessage();
}});
}
}
/**
* Processes unsubscribe requests.
*/
protected static class UnsubscribeDispatcher implements MessageDispatcher
{
public void dispatch (PresentsSession client, Message msg)
{
UnsubscribeRequest req = (UnsubscribeRequest)msg;
int oid = req.getOid();
// log.info("Unsubscribing " + client + "", "oid", oid);
// unsubscribe from the object and clear out our proxy
client.unmapSubscrip(oid);
// post a response to the client letting them know that we will no longer send them
// events regarding this object
client.safePostMessage(new UnsubscribeResponse(oid));
}
}
/**
* Processes forward event requests.
*/
protected static class ForwardEventDispatcher implements MessageDispatcher
{
public void dispatch (PresentsSession client, Message msg)
{
ForwardEventRequest req = (ForwardEventRequest)msg;
DEvent fevt = req.getEvent();
// freak not out if a message arrives from a client just after their session ended
ClientObject clobj = client.getClientObject();
if (clobj == null) {
log.info("Dropping event that arrived after client disconnected " + fevt + ".");
return;
}
// fill in the proper source oid
fevt.setSourceOid(clobj.getOid());
// log.info("Forwarding event", "client", client, "event", fevt);
// forward the event to the omgr for processing
client._omgr.postEvent(fevt);
}
}
/**
* Processes ping requests.
*/
protected static class PingDispatcher implements MessageDispatcher
{
public void dispatch (PresentsSession client, Message msg)
{
// send a pong response using the transport with which the message was received
PingRequest req = (PingRequest)msg;
if (PING_DEBUG) {
log.info("Got ping, ponging", "client", client.getAuthName());
}
client.safePostMessage(new PongResponse(req.getUnpackStamp(), req.getTransport()),
client.getConnection());
}
}
/**
* Processes datagram transmission requests.
*/
protected static class TransmitDatagramsDispatcher implements MessageDispatcher
{
public void dispatch (PresentsSession client, Message msg)
{
log.debug("Client requested datagram transmission", "client", client);
client.getConnection().setTransmitDatagrams(true);
}
}
/**
* Processes throttle updated messages.
*/
protected static class ThrottleUpdatedDispatcher implements MessageDispatcher
{
public void dispatch (final PresentsSession client, Message msg)
{
log.debug("Client ACKed throttle update", "client", client);
client.throttleUpdated();
}
}
/**
* Processes logoff requests.
*/
protected static class LogoffDispatcher implements MessageDispatcher
{
public void dispatch (final PresentsSession client, Message msg)
{
log.debug("Client requested logoff", "client", client);
client.safeEndSession();
}
}
@Inject protected ClientManager _clmgr;
@Inject protected ConnectionManager _conmgr;
@Inject protected PresentsDObjectMgr _omgr;
@Inject protected InvocationManager _invmgr;
protected AuthRequest _areq;
protected Object _authdata;
protected Name _authname;
protected PresentsConnection _conn;
protected ClientObject _clobj;
protected IntMap _subscrips = IntMaps.newHashIntMap();
/**
* Message in which we're currently compounding messages to send, or null if we're sending them
* straight on.
*/
protected CompoundDownstreamMessage _compound;
/**
* The count of startCompoundMessage calls that have occurred without a finishCompoundMessage.
* _compound won't be set until this reaches 0 again.
*/
protected int _compoundDepth;
/** The Oids of objects that have been destroyed while we were subscribed. */
protected HashSet _destroyedSubs = Sets.newHashSet();
protected ClassLoader _loader;
/** The time at which this client started their session. */
protected long _sessionStamp;
/** The time at which this client most recently connected or disconnected. */
protected long _networkStamp;
/** The total number of seconds for which the user was connected to the server in this
* session. */
protected int _connectTime;
/** The configured throttle setting (resent to reconnecting clients). */
protected int _messagesPerSec = Client.DEFAULT_MSGS_PER_SECOND;
/** Prevent the client from sending too many messages too frequently. */
protected Throttle _throttle = createIncomingMessageThrottle();
/** Used to keep throttles around until we know the client is ready for us to apply them. */
protected List _pendingThrottles = Lists.newArrayList();
// keep these for kicks and giggles
protected int _messagesIn;
protected int _messagesOut;
protected int _messagesDropped;
/** A mapping of message dispatchers. */
protected static Map, MessageDispatcher> _disps = Maps.newHashMap();
/** Default period a user is allowed after disconn before their session is forcibly ended. */
protected static final long DEFAULT_FLUSH_TIME = 7 * 60 * 1000L;
// TEMP
protected static final boolean PING_DEBUG = Boolean.getBoolean("ping_debug");
// register our message dispatchers
static {
_disps.put(SubscribeRequest.class, new SubscribeDispatcher());
_disps.put(UnsubscribeRequest.class, new UnsubscribeDispatcher());
_disps.put(ForwardEventRequest.class, new ForwardEventDispatcher());
_disps.put(PingRequest.class, new PingDispatcher());
_disps.put(TransmitDatagramsRequest.class, new TransmitDatagramsDispatcher());
_disps.put(ThrottleUpdatedMessage.class, new ThrottleUpdatedDispatcher());
_disps.put(LogoffRequest.class, new LogoffDispatcher());
_disps.put(CompoundUpstreamMessage.class, new CompoundDispatcher());
}
}