jaroslav@238: /**
jaroslav@238:  * The MIT License (MIT)
jaroslav@238:  *
jaroslav@238:  * Copyright (C) 2013 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
jaroslav@238:  *
jaroslav@238:  * Permission is hereby granted, free of charge, to any person obtaining a copy
jaroslav@238:  * of this software and associated documentation files (the "Software"), to deal
jaroslav@238:  * in the Software without restriction, including without limitation the rights
jaroslav@238:  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
jaroslav@238:  * copies of the Software, and to permit persons to whom the Software is
jaroslav@238:  * furnished to do so, subject to the following conditions:
jaroslav@238:  *
jaroslav@238:  * The above copyright notice and this permission notice shall be included in
jaroslav@238:  * all copies or substantial portions of the Software.
jaroslav@238:  *
jaroslav@238:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
jaroslav@238:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
jaroslav@238:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
jaroslav@238:  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
jaroslav@238:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
jaroslav@238:  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
jaroslav@238:  * THE SOFTWARE.
jaroslav@238:  */
jaroslav@238: package org.apidesign.demo.chat.server;
jaroslav@238: 
jaroslav@238: import java.util.ArrayList;
jaroslav@238: import java.util.IdentityHashMap;
jaroslav@238: import java.util.List;
jaroslav@238: import java.util.Map;
jaroslav@238: import java.util.logging.Logger;
jaroslav@238: import javax.inject.Singleton;
jaroslav@238: import javax.ws.rs.Consumes;
jaroslav@238: import javax.ws.rs.DefaultValue;
jaroslav@238: import javax.ws.rs.GET;
jaroslav@238: import javax.ws.rs.POST;
jaroslav@238: import javax.ws.rs.Path;
jaroslav@238: import javax.ws.rs.Produces;
jaroslav@238: import javax.ws.rs.QueryParam;
jaroslav@238: import javax.ws.rs.container.AsyncResponse;
jaroslav@238: import javax.ws.rs.container.Suspended;
jaroslav@238: import javax.ws.rs.core.MediaType;
jaroslav@238: import org.apidesign.demo.chat.shared.Message;
jaroslav@238: import org.apidesign.demo.chat.shared.Query;
jaroslav@238: 
jaroslav@238: /** Server side of the chat application.*/
jaroslav@238: @Path("/chat/") @Singleton
jaroslav@238: public final class ChatServerResource {
jaroslav@238:     private static final Logger LOG = Logger.getLogger(ChatServerResource.class.getName());
jaroslav@238:     private static final long started = System.currentTimeMillis() - 10;
jaroslav@238:     
jaroslav@238:     private List<Message> msgs = new ArrayList<>();
jaroslav@238:     {
jaroslav@238:         Message welcome = new Message();
jaroslav@238:         welcome.setUser("system");
jaroslav@238:         welcome.setComment("Welcome and enjoy!");
jaroslav@238:         welcome.setSince(10);
jaroslav@238:         msgs.add(welcome);
jaroslav@238:     }
jaroslav@238:     
jaroslav@238:     private final Map<AsyncResponse, Long> awaiting = new IdentityHashMap<>();
jaroslav@238:     
jaroslav@238:     @Produces(MediaType.APPLICATION_JSON)
jaroslav@238:     @GET public synchronized void getResources(
jaroslav@238:         @QueryParam("since") @DefaultValue("0") long since,
jaroslav@238:         @Suspended AsyncResponse ar
jaroslav@238:     ) {
jaroslav@238:         Query q = new Query();
jaroslav@238:         for (Message m : msgs) {
jaroslav@238:             if (m.getSince()>= since) {
jaroslav@238:                 q.getMessages().add(m);
jaroslav@238:             }
jaroslav@238:         }
jaroslav@238:         if (!q.getMessages().isEmpty()) {
jaroslav@238:             ar.resume(q);
jaroslav@238:         } else {
jaroslav@238:             awaiting.put(ar, since);
jaroslav@238:         }
jaroslav@238:     }
jaroslav@238:     
jaroslav@238:     private void handleAwaiting(long newest) {
jaroslav@238:         assert Thread.holdsLock(this);
jaroslav@238:         AGAIN: for (;;) {
jaroslav@238:             for (Map.Entry<AsyncResponse, Long> entry : awaiting.entrySet()) {
jaroslav@238:                 AsyncResponse ar = entry.getKey();
jaroslav@238:                 Long since = entry.getValue();
jaroslav@238:                 if (since <= newest) {
jaroslav@238:                     awaiting.remove(ar);
jaroslav@238:                     getResources(since, ar);
jaroslav@238:                     continue AGAIN;
jaroslav@238:                 }
jaroslav@238:             }
jaroslav@238:             return;
jaroslav@238:         }
jaroslav@238:     }
jaroslav@238:     
jaroslav@238:     @POST @Consumes(value = MediaType.APPLICATION_JSON)
jaroslav@238:     public synchronized Message publish(Message msg) {
jaroslav@238:         msg.setSince(System.currentTimeMillis() - started);
jaroslav@238:         msgs.add(msg);
jaroslav@238:         handleAwaiting(msg.getSince());
jaroslav@238:         return msg;
jaroslav@238:     }
jaroslav@238: }