restconf/restconf-nb/src/main/java/org/opendaylight/restconf/nb/rfc8040/streams/WebSocketInitializer.java

   1 /*
   2  * Copyright © 2019 FRINX s.r.o. All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.restconf.nb.rfc8040.streams;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  12 import java.util.concurrent.ScheduledExecutorService;
  13 import javax.inject.Inject;
  14 import javax.inject.Singleton;
  15 import javax.servlet.http.HttpServletResponse;
  16 import org.eclipse.jetty.websocket.servlet.ServletUpgradeRequest;
  17 import org.eclipse.jetty.websocket.servlet.ServletUpgradeResponse;
  18 import org.eclipse.jetty.websocket.servlet.WebSocketCreator;
  19 import org.eclipse.jetty.websocket.servlet.WebSocketServlet;
  20 import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
  21 import org.opendaylight.controller.config.threadpool.ScheduledThreadPool;
  22 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.ListenersBroker;
  23 import org.slf4j.Logger;
  24 import org.slf4j.LoggerFactory;
  25
  26 /**
  27  * Web-socket servlet listening on ws or wss schemas for created data-change-event or notification streams.
  28  */
  29 @Singleton
  30 public final class WebSocketInitializer extends WebSocketServlet {
  31     private static final long serialVersionUID = 1L;
  32
  33     @SuppressFBWarnings(value = "SE_BAD_FIELD",
  34         justification = "Servlet/WebSocket bridge, we need this service for heartbeats")
  35     private final ScheduledExecutorService executorService;
  36     private final int maximumFragmentLength;
  37     private final int heartbeatInterval;
  38     private final int idleTimeoutMillis;
  39
  40     /**
  41      * Creation of the web-socket initializer.
  42      *
  43      * @param scheduledThreadPool    ODL thread pool used for fetching of scheduled executors.
  44      * @param configuration          Web-socket configuration holder.
  45      */
  46     @Inject
  47     public WebSocketInitializer(final ScheduledThreadPool scheduledThreadPool, final Configuration configuration) {
  48         executorService = scheduledThreadPool.getExecutor();
  49         maximumFragmentLength = configuration.getMaximumFragmentLength();
  50         heartbeatInterval = configuration.getHeartbeatInterval();
  51         idleTimeoutMillis = configuration.getIdleTimeout();
  52     }
  53
  54     /**
  55      * Configuration of the web-socket factory - idle timeout and specified factory object.
  56      *
  57      * @param factory Configurable web-socket factory.
  58      */
  59     @Override
  60     public void configure(final WebSocketServletFactory factory) {
  61         factory.getPolicy().setIdleTimeout(idleTimeoutMillis);
  62         factory.setCreator(new WebSocketFactory(executorService, maximumFragmentLength, heartbeatInterval));
  63     }
  64
  65     /**
  66      * Factory that is used for creation of new web-sockets based on HTTP/HTTPS upgrade request.
  67      */
  68     @VisibleForTesting
  69     static final class WebSocketFactory implements WebSocketCreator {
  70         private static final Logger LOG = LoggerFactory.getLogger(WebSocketFactory.class);
  71
  72         private final ScheduledExecutorService executorService;
  73         // FIXME: inject this reference
  74         private final ListenersBroker listenersBroker = ListenersBroker.getInstance();
  75         private final int maximumFragmentLength;
  76         private final int heartbeatInterval;
  77
  78         /**
  79          * Creation of the web-socket factory.
  80          *
  81          * @param executorService       Executor for creation of threads for controlling of web-socket sessions.
  82          * @param maximumFragmentLength Maximum web-socket fragment length in number of Unicode code units (characters)
  83          *                              (exceeded message length leads to fragmentation of messages).
  84          * @param heartbeatInterval     Interval in milliseconds between sending of ping control frames.
  85          */
  86         WebSocketFactory(final ScheduledExecutorService executorService, final int maximumFragmentLength,
  87                 final int heartbeatInterval) {
  88             this.executorService = executorService;
  89             this.maximumFragmentLength = maximumFragmentLength;
  90             this.heartbeatInterval = heartbeatInterval;
  91         }
  92
  93         /**
  94          * Creation of the new web-socket based on input HTTP/HTTPS upgrade request. Web-socket is created only if the
  95          * data listener for input URI can be found (results in status code 101); otherwise status code 404 is set
  96          * in upgrade response.
  97          *
  98          * @param servletUpgradeRequest  Upgrade request.
  99          * @param servletUpgradeResponse Upgrade response.
 100          * @return Created web-socket instance or {@code null} if the web-socket cannot be created.
 101          */
 102         @Override
 103         public Object createWebSocket(final ServletUpgradeRequest servletUpgradeRequest,
 104                 final ServletUpgradeResponse servletUpgradeResponse) {
 105             final var streamName = ListenersBroker.createStreamNameFromUri(
 106                 servletUpgradeRequest.getRequestURI().getRawPath());
 107
 108             final var listener = listenersBroker.listenerFor(streamName);
 109             if (listener == null) {
 110                 LOG.debug("Listener for stream with name {} was not found.", streamName);
 111                 servletUpgradeResponse.setSuccess(false);
 112                 servletUpgradeResponse.setStatusCode(HttpServletResponse.SC_NOT_FOUND);
 113                 return null;
 114             }
 115
 116             LOG.debug("Listener for stream with name {} has been found, web-socket session handler will be created",
 117                 streamName);
 118             servletUpgradeResponse.setSuccess(true);
 119             servletUpgradeResponse.setStatusCode(HttpServletResponse.SC_SWITCHING_PROTOCOLS);
 120             // note: every web-socket manages PING process individually because this approach scales better than
 121             //       sending of PING frames at once over all web-socket sessions
 122             return new WebSocketSessionHandler(executorService, listener, maximumFragmentLength, heartbeatInterval);
 123         }
 124     }
 125 }