/**
* Copyright 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.waveprotocol.box.server.rpc;
import com.google.common.base.Preconditions;
import com.google.common.collect.BiMap;
import com.google.common.collect.HashBiMap;
import com.google.protobuf.Descriptors.MethodDescriptor;
import com.google.protobuf.Message;
import com.google.protobuf.RpcCallback;
import com.google.protobuf.RpcController;
import com.google.protobuf.UnknownFieldSet;
import com.sixfire.websocket.WebSocket;
import org.waveprotocol.wave.util.logging.Log;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Implementation of {@link ClientRpcChannel} based on a
* {@link WebSocketClientChannel}.
*/
public class WebSocketClientRpcChannel implements ClientRpcChannel {
private static final Log LOG = Log.get(WebSocketClientRpcChannel.class);
private final MessageExpectingChannel protoChannel;
private final AtomicInteger lastSequenceNumber = new AtomicInteger();
private final BiMap<Integer, ClientRpcController> activeMethodMap = HashBiMap.create();
/**
* Set up a new WebSocketClientRpcChannel pointing at the given server
* address.
*
* @param serverAddress the target server address
* @param threadPool threadpool for performing async reads.
*/
public WebSocketClientRpcChannel(SocketAddress serverAddress, ExecutorService threadPool)
throws IOException {
Preconditions.checkNotNull(serverAddress, "null serverAddress");
ProtoCallback callback = new ProtoCallback() {
@Override
public void message(int sequenceNo, Message message) {
final ClientRpcController controller;
synchronized (activeMethodMap) {
controller = activeMethodMap.get(sequenceNo);
// TODO: remove controller from activeMethodMap
}
if (message instanceof Rpc.RpcFinished) {
Rpc.RpcFinished finished = (Rpc.RpcFinished) message;
if (finished.getFailed()) {
controller.failure(finished.getErrorText());
} else {
controller.response(null);
}
} else {
controller.response(message);
}
}
private void unknown(long sequenceNo, String messageType) {
final ClientRpcController controller;
synchronized (activeMethodMap) {
controller = activeMethodMap.get(sequenceNo);
}
controller.failure("Client RPC got unknown message: " + messageType);
}
@Override
public void unknown(int sequenceNo, String messageType, UnknownFieldSet message) {
unknown(sequenceNo, messageType);
}
@Override
public void unknown(int sequenceNo, String messageType, String message) {
unknown(sequenceNo, messageType);
}
};
WebSocket websocket = openWebSocket((InetSocketAddress) serverAddress);
protoChannel = new WebSocketClientChannel(websocket, callback, threadPool);
protoChannel.expectMessage(Rpc.RpcFinished.getDefaultInstance());
protoChannel.startAsyncRead();
LOG.fine("Opened a new WebSocketClientRpcChannel to " + serverAddress);
}
/**
* Create a new WebSocketClientRpcChannel backed onto a new single thread
* executor.
*/
public WebSocketClientRpcChannel(SocketAddress serverAddress) throws IOException {
this(serverAddress, Executors.newSingleThreadExecutor());
}
@Override
public RpcController newRpcController() {
return new ClientRpcController(this);
}
@Override
public void callMethod(MethodDescriptor method, RpcController genericRpcController,
Message request, Message responsePrototype, RpcCallback<Message> callback) {
// Cast the given generic controller to a ClientRpcController.
final ClientRpcController controller;
if (genericRpcController instanceof ClientRpcController) {
controller = (ClientRpcController) genericRpcController;
} else {
throw new IllegalArgumentException("Expected ClientRpcController, got: "
+ genericRpcController.getClass());
}
// Generate a new sequence number, and configure the controller - notably,
// this throws an IllegalStateException if it is *already* configured.
final int sequenceNo = lastSequenceNumber.incrementAndGet();
final ClientRpcController.RpcState rpcStatus =
new ClientRpcController.RpcState(this, method.getOptions()
.getExtension(Rpc.isStreamingRpc), callback, new Runnable() {
@Override
public void run() {
protoChannel.sendMessage(sequenceNo, Rpc.CancelRpc.getDefaultInstance());
}
});
controller.configure(rpcStatus);
synchronized (activeMethodMap) {
activeMethodMap.put(sequenceNo, controller);
}
LOG.fine("Calling a new RPC (seq " + sequenceNo + "), method " + method.getFullName() + " for "
+ protoChannel);
// Kick off the RPC by sending the request to the server end-point.
protoChannel.sendMessage(sequenceNo, request, responsePrototype);
}
private WebSocket openWebSocket(InetSocketAddress inetAddress) throws IOException {
URI uri;
try {
uri = new URI("ws", null, inetAddress.getHostName(), inetAddress.getPort(), "/socket",
null, null);
} catch (URISyntaxException e) {
LOG.severe("Unable to create ws:// uri from given address (" + inetAddress + ")", e);
throw new IllegalStateException(e);
}
WebSocket websocket = new WebSocket(uri);
websocket.connect();
return websocket;
}
}