com.threerings.presents.server.InvocationManager 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.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.List;
import java.util.Map;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Multimap;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.samskivert.util.IntMap;
import com.samskivert.util.IntMaps;
import com.samskivert.util.LRUHashMap;
import com.samskivert.util.StringUtil;
import com.threerings.io.Streamable;
import com.threerings.presents.client.Client;
import com.threerings.presents.data.ClientObject;
import com.threerings.presents.data.InvocationCodes;
import com.threerings.presents.data.InvocationMarshaller;
import com.threerings.presents.data.InvocationMarshaller.ListenerMarshaller;
import com.threerings.presents.dobj.DEvent;
import com.threerings.presents.dobj.DObject;
import com.threerings.presents.dobj.EventListener;
import com.threerings.presents.dobj.InvocationRequestEvent;
import com.threerings.presents.net.Transport;
import static com.threerings.presents.Log.log;
/**
* The invocation services provide client to server invocations (service requests) and server to
* client invocations (responses and notifications). Via this mechanism, the client can make
* requests of the server, be notified of its response and the server can asynchronously invoke
* code on the client.
*
* Invocations are like remote procedure calls in that they are named and take arguments. All
* arguments must be {@link Streamable} objects, primitive types, or String objects. All arguments
* are passed by value (by serializing and unserializing the arguments); there is no special
* facility provided for referencing non-local objects (it is assumed that the distributed object
* facility will already be in use for any objects that should be shared).
*
*
The server invocation manager listens for invocation requests from the client and passes
* them on to the invocation provider registered for the requested invocation module. It also
* provides a mechanism by which responses and asynchronous notification invocations can be
* delivered to the client.
*/
@Singleton
public class InvocationManager
implements EventListener
{
/**
* Constructs an invocation manager which will use the supplied distributed object manager to
* operate its invocation services. Generally only one invocation manager should be operational
* in a particular system.
*/
@Inject public InvocationManager (PresentsDObjectMgr omgr)
{
_omgr = omgr;
_omgr._invmgr = this;
// create the object on which we'll listen for invocation requests
DObject invobj = _omgr.registerObject(new DObject());
invobj.addListener(this);
_invoid = invobj.getOid();
log.debug("Created invocation service object", "oid", _invoid);
}
/**
* Returns the object id of the invocation services object.
*/
public int getOid ()
{
return _invoid;
}
/**
* Registers the supplied invocation service provider.
*
* @param provider the provider to be registered.
* @param mclass the class of the invocation marshaller generated for the service.
*/
public > T registerProvider (
InvocationProvider provider, Class mclass)
{
return registerProvider(provider, mclass, null);
}
/**
* Registers the supplied invocation service provider.
*
* @param provider the provider to be registered.
* @param mclass the class of the invocation marshaller generated for the service.
* @param group the bootstrap group in which this marshaller is to be registered, or null if it
* is not a bootstrap service. Do not: register a marshaller with multiple boot
* groups. You must collect shared marshaller into as fine grained a set of groups as necessary
* and have different types of clients specify the list of groups they need.
*/
public > T registerProvider (
final InvocationProvider provider, Class mclass, String group)
{
_omgr.requireEventThread(); // sanity check
// find the invocation provider interface class (defaulting to the concrete class to cope
// with legacy non-interface based providers)
Class pclass = provider.getClass();
String pname = mclass.getSimpleName().replaceAll("Marshaller", "Provider");
OUTER:
for (Class sclass = pclass; sclass != null; sclass = sclass.getSuperclass()) {
for (Class iclass : sclass.getInterfaces()) {
if (InvocationProvider.class.isAssignableFrom(iclass) &&
iclass.getSimpleName().equals(pname)) {
pclass = iclass;
break OUTER;
}
}
}
// determine the invocation service code mappings
final Map invmeths = Maps.newHashMap();
for (Method method : pclass.getMethods()) {
Class[] ptypes = method.getParameterTypes();
// only consider methods whose first argument is of type ClientObject; this is a
// non-issue if we are looking at an auto-generated FooProvider interface, but is
// necessary to avoid problems for legacy concrete FooProvider implementations that
// also happen to have overloaded methods with the same name as invocation service
// methods; I'm looking at you ChatProvider...
if (ptypes.length == 0 || !ClientObject.class.isAssignableFrom(ptypes[0])) {
continue;
}
try {
Field code = mclass.getField(StringUtil.unStudlyName(method.getName()));
invmeths.put(code.getInt(null), method);
} catch (IllegalAccessException iae) {
throw new RuntimeException(iae); // Field.get failed? shouldn't happen
} catch (NoSuchFieldException nsfe) {
// not a problem, they just added some extra methods to their provider
}
}
// get the next invocation code
int invCode = nextInvCode();
// create a marshaller instance and initialize it
T marsh;
try {
marsh = mclass.newInstance();
marsh.init(_invoid, invCode, _standaloneClient == null ?
null : _standaloneClient.getInvocationDirector());
} catch (IllegalAccessException ie) {
throw new RuntimeException(ie);
} catch (InstantiationException ie) {
throw new RuntimeException(ie);
}
// register the dispatcher
_dispatchers.put(invCode, new Dispatcher() {
public InvocationProvider getProvider () {
return provider;
}
public void dispatchRequest (ClientObject source, int methodId, Object[] args)
throws InvocationException {
// locate the method to be invoked
Method m = invmeths.get(methodId);
if (m == null) {
String pclass = StringUtil.shortClassName(provider.getClass());
log.warning("Requested to dispatch unknown method", "source", source.who(),
"methodId", methodId, "provider", pclass, "args", args);
throw new InvocationException(InvocationCodes.E_INTERNAL_ERROR);
}
// prepare the arguments: the ClientObject followed by the service method args
Object[] fargs = new Object[args.length+1];
System.arraycopy(args, 0, fargs, 1, args.length);
fargs[0] = source;
// actually invoke the method, and cope with failure
try {
m.invoke(provider, fargs);
} catch (IllegalAccessException ie) {
throw new RuntimeException(ie); // should never happen
} catch (InvocationTargetException ite) {
Throwable cause = ite.getCause();
if (cause instanceof InvocationException) {
throw (InvocationException)cause;
} else {
log.warning("Invocation service method failure",
"provider", StringUtil.shortClassName(provider.getClass()),
"method", m.getName(), "args", fargs, cause);
throw new InvocationException(InvocationCodes.E_INTERNAL_ERROR);
}
}
}
});
// if it's a bootstrap service, slap it in the list
if (group != null) {
_bootlists.put(group, marsh);
}
_recentRegServices.put(Integer.valueOf(invCode), marsh.getClass().getName());
log.debug("Registered service", "code", invCode, "marsh", marsh);
return marsh;
}
/**
* Registers the supplied invocation dispatcher, returning a marshaller that can be used to
* send requests to the provider for whom the dispatcher is proxying.
*
* @param dispatcher the dispatcher to be registered.
*/
public > T registerDispatcher (
InvocationDispatcher dispatcher)
{
return registerDispatcher(dispatcher, null);
}
/**
* @deprecated use {@link #registerDispatcher(InvocationDispatcher)}.
*/
@Deprecated public > T registerDispatcher (
InvocationDispatcher dispatcher, boolean bootstrap)
{
return registerDispatcher(dispatcher, null);
}
/**
* Registers the supplied invocation dispatcher, returning a marshaller that can be used to
* send requests to the provider for whom the dispatcher is proxying.
*
* @param dispatcher the dispatcher to be registered.
* @param group the bootstrap group in which this marshaller is to be registered, or null if it
* is not a bootstrap service. Do not: register a dispatcher with multiple boot
* groups. You must collect shared dispatchers into as fine grained a set of groups as
* necessary and have different types of clients specify the list of groups they need.
*/
public > T registerDispatcher (
InvocationDispatcher dispatcher, String group)
{
_omgr.requireEventThread(); // sanity check
// get the next invocation code
int invCode = nextInvCode();
// create the marshaller and initialize it
T marsh = dispatcher.createMarshaller();
marsh.init(_invoid, invCode, _standaloneClient == null ?
null : _standaloneClient.getInvocationDirector());
// register the dispatcher
_dispatchers.put(invCode, dispatcher);
// if it's a bootstrap service, slap it in the list
if (group != null) {
_bootlists.put(group, marsh);
}
_recentRegServices.put(Integer.valueOf(invCode), marsh.getClass().getName());
log.debug("Registered service", "code", invCode, "marsh", marsh);
return marsh;
}
/**
* Clears out a dispatcher registration. This should be called to free up resources when an
* invocation service is no longer going to be used.
*/
public void clearDispatcher (InvocationMarshaller marsh)
{
_omgr.requireEventThread(); // sanity check
if (marsh == null) {
log.warning("Refusing to unregister null marshaller.", new Exception());
return;
}
if (_dispatchers.remove(marsh.getInvocationCode()) == null) {
log.warning("Requested to remove unregistered marshaller?", "marsh", marsh,
new Exception());
}
}
/**
* Constructs a list of all bootstrap services registered in any of the supplied groups.
*/
public List> getBootstrapServices (String[] bootGroups)
{
List> services = Lists.newArrayList();
for (String group : bootGroups) {
services.addAll(_bootlists.get(group));
}
return services;
}
/**
* Get the class that is being used to dispatch the specified invocation code, for
* informational purposes.
*
* @return the Class, or null if no dispatcher is registered with
* the specified code.
*/
public Class getDispatcherClass (int invCode)
{
Object dispatcher = _dispatchers.get(invCode);
return (dispatcher == null) ? null : dispatcher.getClass();
}
// documentation inherited from interface
public void eventReceived (DEvent event)
{
log.debug("Event received", "event", event);
if (event instanceof InvocationRequestEvent) {
InvocationRequestEvent ire = (InvocationRequestEvent)event;
dispatchRequest(ire.getSourceOid(), ire.getInvCode(),
ire.getMethodId(), ire.getArgs(), ire.getTransport());
}
}
/**
* Called when we receive an invocation request message. Dispatches the request to the
* appropriate invocation provider via the registered invocation dispatcher.
*/
protected void dispatchRequest (
int clientOid, int invCode, int methodId, Object[] args, Transport transport)
{
// make sure the client is still around
ClientObject source = (ClientObject)_omgr.getObject(clientOid);
if (source == null) {
log.info("Client no longer around for invocation request", "clientOid", clientOid,
"code", invCode, "methId", methodId, "args", args);
return;
}
// look up the dispatcher
Dispatcher disp = _dispatchers.get(invCode);
if (disp == null) {
log.info("Received invocation request but dispatcher registration was already cleared",
"code", invCode, "methId", methodId, "args", args,
"marsh", _recentRegServices.get(Integer.valueOf(invCode)));
return;
}
// scan the args, initializing any listeners and keeping track of the "primary" listener
ListenerMarshaller rlist = null;
int acount = args.length;
for (int ii = 0; ii < acount; ii++) {
Object arg = args[ii];
if (arg instanceof ListenerMarshaller) {
ListenerMarshaller list = (ListenerMarshaller)arg;
list.callerOid = clientOid;
list.omgr = _omgr;
list.transport = transport;
// keep track of the listener we'll inform if anything
// goes horribly awry
if (rlist == null) {
rlist = list;
}
}
}
log.debug("Dispatching invreq", "caller", source.who(), "provider", disp.getProvider(),
"methId", methodId, "args", args);
// dispatch the request
try {
if (rlist != null) {
rlist.setInvocationId(
StringUtil.shortClassName(disp.getProvider()) + ", methodId=" + methodId);
}
disp.dispatchRequest(source, methodId, args);
} catch (InvocationException ie) {
if (rlist != null) {
rlist.requestFailed(ie.getMessage());
} else {
log.warning("Service request failed but we've got no listener to inform of " +
"the failure", "caller", source.who(), "code", invCode,
"provider", disp.getProvider(), "methodId", methodId, "args", args,
"error", ie);
}
} catch (Throwable t) {
log.warning("Dispatcher choked", "provider", disp.getProvider(), "caller", source.who(),
"methId", methodId, "args", args, t);
// avoid logging an error when the listener notices that it's been ignored.
if (rlist != null) {
rlist.setNoResponse();
}
}
}
/**
* Used to generate monotonically increasing provider ids.
*/
protected synchronized int nextInvCode ()
{
return _invCode++;
}
protected interface Dispatcher {
public InvocationProvider getProvider ();
public void dispatchRequest (ClientObject source, int methodId, Object[] args)
throws InvocationException;
}
/** The object id of the object on which we receive invocation service requests. */
protected int _invoid = -1;
/** Used to generate monotonically increasing provider ids. */
protected int _invCode;
/** A reference to the standalone client, if any. */
@Inject(optional=true) protected Client _standaloneClient;
/** The distributed object manager we're working with. */
protected PresentsDObjectMgr _omgr;
/** A table of invocation dispatchers each mapped by a unique code. */
protected IntMap _dispatchers = IntMaps.newHashIntMap();
/** Maps bootstrap group to lists of services to be provided to clients at boot time. */
protected Multimap> _bootlists = ArrayListMultimap.create();
/** Tracks recently registered services so that we can complain informatively if a request
* comes in on a service we don't know about. */
protected final Map _recentRegServices =
new LRUHashMap(10000);
}