/*
* (C) Copyright 2013 Kurento (http://kurento.org/)
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the GNU Lesser General Public License
* (LGPL) version 2.1 which accompanies this distribution, and is available at
* http://www.gnu.org/licenses/lgpl-2.1.html
*
* 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.
*
*/
package com.kurento.kmf.jsonrpcconnector.internal.server;
import static com.kurento.kmf.jsonrpcconnector.internal.JsonRpcConstants.METHOD_RECONNECT;
import static com.kurento.kmf.jsonrpcconnector.internal.JsonRpcConstants.RECONNECTION_ERROR;
import static com.kurento.kmf.jsonrpcconnector.internal.JsonRpcConstants.RECONNECTION_SUCCESSFUL;
import java.io.IOException;
import java.lang.reflect.Type;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.concurrent.ScheduledFuture;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.core.task.TaskRejectedException;
import org.springframework.scheduling.TaskScheduler;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.reflect.TypeToken;
import com.kurento.kmf.common.SecretGenerator;
import com.kurento.kmf.jsonrpcconnector.JsonRpcHandler;
import com.kurento.kmf.jsonrpcconnector.JsonUtils;
import com.kurento.kmf.jsonrpcconnector.internal.JsonRpcHandlerManager;
import com.kurento.kmf.jsonrpcconnector.internal.client.TransactionImpl.ResponseSender;
import com.kurento.kmf.jsonrpcconnector.internal.message.Request;
import com.kurento.kmf.jsonrpcconnector.internal.message.Response;
import com.kurento.kmf.jsonrpcconnector.internal.message.ResponseError;
public class ProtocolManager {
public interface ServerSessionFactory {
ServerSession createSession(String sessionId, Object registerInfo,
SessionsManager sessionsManager);
}
private static final Logger log = LoggerFactory
.getLogger(ProtocolManager.class);
protected SecretGenerator secretGenerator = new SecretGenerator();
@Autowired
private SessionsManager sessionsManager;
@Autowired
@Qualifier("jsonrpcTaskScheduler")
private TaskScheduler taskScheduler;
private final JsonRpcHandlerManager handlerManager;
public ProtocolManager(JsonRpcHandler<?> handler) {
this.handlerManager = new JsonRpcHandlerManager(handler);
}
/**
* Process incoming message. The response is sent using responseSender. If
* null, the session will be used.
*
* @param messageJson
* @param factory
* @param responseSender
* @param internalSessionId
* @throws IOException
*/
public void processMessage(String messageJson,
ServerSessionFactory factory, ResponseSender responseSender,
String internalSessionId) throws IOException {
JsonObject messagetJsonObject = JsonUtils.fromJson(messageJson,
JsonObject.class);
if (messagetJsonObject.has(Request.METHOD_FIELD_NAME)) {
processRequestMessage(factory, messagetJsonObject, responseSender,
internalSessionId);
} else {
processResponseMessage(messagetJsonObject, internalSessionId);
}
}
// TODO Unify ServerSessionFactory, ResponseSender and transportId in a
// entity "RequestContext" or similar. In this way, there are less
// parameters
// and the implementation is easier
private void processRequestMessage(ServerSessionFactory factory,
JsonObject requestJsonObject, ResponseSender responseSender,
String transportId) throws IOException {
Request<JsonElement> request = JsonUtils.fromJsonRequest(
requestJsonObject, JsonElement.class);
if (request.getMethod().equals(METHOD_RECONNECT)) {
processReconnectMessage(factory, request, responseSender,
transportId);
} else {
ServerSession session = getSession(factory, transportId, request);
// TODO, Take out this an put in Http specific handler. The main
// reason is to wait for request before responding to the client.
// And for no contaminate the ProtocolManager.
if (request.getMethod().equals(Request.POLL_METHOD_NAME)) {
Type collectionType = new TypeToken<List<Response<JsonElement>>>() {
}.getType();
List<Response<JsonElement>> responseList = JsonUtils.fromJson(
request.getParams(), collectionType);
for (Response<JsonElement> response : responseList) {
session.handleResponse(response);
}
// Wait for some time if there is a request from server to
// client
// TODO Allow send empty responses. Now you have to send at
// least an
// empty string
responseSender.sendResponse(new Response<Object>(request
.getId(), Collections.emptyList()));
} else {
handlerManager.handleRequest(session, request, responseSender);
}
}
}
private ServerSession getSession(ServerSessionFactory factory,
String transportId, Request<JsonElement> request) {
ServerSession session = null;
if (request.getSessionId() != null) {
session = sessionsManager.get(request.getSessionId());
if (session == null) {
log.warn("There is no session with specified id '{}'."
+ "Creating a new one.", request.getSessionId());
}
} else if (transportId != null) {
session = sessionsManager.getByTransportId(transportId);
}
if (session == null) {
session = createSession(factory, session);
handlerManager.afterConnectionEstablished(session);
} else {
session.setNew(false);
}
return session;
}
private void processReconnectMessage(ServerSessionFactory factory,
Request<JsonElement> request, ResponseSender responseSender,
String transportId) throws IOException {
String sessionId = request.getSessionId();
if (sessionId == null) {
responseSender
.sendResponse(new Response<>(
request.getId(),
new ResponseError(99999,
"SessionId is mandatory in a reconnection request")));
} else {
ServerSession session = sessionsManager.get(sessionId);
if (session != null) {
String oldTransportId = session.getTransportId();
session.setTransportId(transportId);
sessionsManager.updateTransportId(session, oldTransportId);
responseSender.sendResponse(new Response<>(sessionId, request
.getId(), RECONNECTION_SUCCESSFUL));
} else {
responseSender.sendResponse(new Response<>(request.getId(),
new ResponseError(99999, RECONNECTION_ERROR)));
}
}
}
private ServerSession createSession(ServerSessionFactory factory,
Object registerInfo) {
String sessionId = secretGenerator.nextSecret();
ServerSession session = factory.createSession(sessionId, registerInfo,
sessionsManager);
sessionsManager.put(session);
return session;
}
private void processResponseMessage(JsonObject messagetJsonObject,
String internalSessionId) {
Response<JsonElement> response = JsonUtils.fromJsonResponse(
messagetJsonObject, JsonElement.class);
ServerSession session = sessionsManager
.getByTransportId(internalSessionId);
session.handleResponse(response);
}
public void closeSessionIfTimeout(final String transportId,
final String reason) {
final ServerSession session = sessionsManager
.getByTransportId(transportId);
if (session != null) {
log.info("Configuring close timeout for session: {}",
session.getSessionId());
try {
ScheduledFuture<?> lastStartedTimerFuture = taskScheduler
.schedule(
new Runnable() {
@Override
public void run() {
closeSession(session, reason);
}
},
new Date(
System.currentTimeMillis()
+ session
.getReconnectionTimeoutInMillis()));
session.setCloseTimerTask(lastStartedTimerFuture);
} catch (TaskRejectedException e) {
log.warn("Close timeout for session {} can not be set "
+ "because the scheduler is shutdown",
session.getSessionId());
}
}
}
public void closeSession(ServerSession session, String reason) {
log.info("Closing session: {}", session.getSessionId());
sessionsManager.remove(session);
handlerManager.afterConnectionClosed(session, reason);
}
public void cancelCloseTimer(ServerSession session) {
if (session.getCloseTimerTask() != null) {
session.getCloseTimerTask().cancel(false);
}
}
}