Seed code for biermann restconf

Seed initial code from OpenDaylight netconf project for
Biermann draft version of restconf API

Issue-ID: CCSDK-3783
Signed-off-by: Dan Timoney <dtimoney@att.com>
Change-Id: I8a1ad2050ee7addbb480f01bd448922803bff31f

1 files changed, 152 insertions, 0 deletions

diff --git a/netconf/restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/netconf/sal/streams/websockets/WebSocketServer.java b/netconf/restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/netconf/sal/streams/websockets/WebSocketServer.java
new file mode 100644
index 0000000..a295c54
--- /dev/null
+++ b/netconf/restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/netconf/sal/streams/websockets/WebSocketServer.java
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2014, 2015 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.netconf.sal.streams.websockets;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
+import static java.util.Objects.requireNonNull;
+
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.channel.Channel;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.nio.NioServerSocketChannel;
+import org.opendaylight.netconf.sal.streams.listeners.Notificator;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * {@link WebSocketServer} is the singleton responsible for starting and stopping the
+ * web socket server.
+ */
+public final class WebSocketServer implements Runnable {
+
+    private static final Logger LOG = LoggerFactory.getLogger(WebSocketServer.class);
+
+    private static final String DEFAULT_ADDRESS = "0.0.0.0";
+
+    private static WebSocketServer instance = null;
+
+    private final String address;
+    private final int port;
+
+    private EventLoopGroup bossGroup;
+    private EventLoopGroup workerGroup;
+
+
+    private WebSocketServer(final String address, final int port) {
+        this.address = address;
+        this.port = port;
+    }
+
+    /**
+     * Create singleton instance of {@link WebSocketServer}.
+     *
+     * @param port TCP port used for this server
+     * @return instance of {@link WebSocketServer}
+     */
+    private static WebSocketServer createInstance(final int port) {
+        instance = createInstance(DEFAULT_ADDRESS, port);
+        return instance;
+    }
+
+    public static WebSocketServer createInstance(final String address, final int port) {
+        checkState(instance == null, "createInstance() has already been called");
+        checkArgument(port >= 1024, "Privileged port (below 1024) is not allowed");
+
+        instance = new WebSocketServer(requireNonNull(address, "Address cannot be null."), port);
+        LOG.info("Created WebSocketServer on {}:{}", address, port);
+        return instance;
+    }
+
+    /**
+     * Get the websocket of TCP port.
+     *
+     * @return websocket TCP port
+     */
+    public int getPort() {
+        return port;
+    }
+
+    /**
+     * Get instance of {@link WebSocketServer} created by {@link #createInstance(int)}.
+     *
+     * @return instance of {@link WebSocketServer}
+     */
+    public static WebSocketServer getInstance() {
+        return requireNonNull(instance, "createInstance() must be called prior to getInstance()");
+    }
+
+    /**
+     * Get instance of {@link WebSocketServer} created by {@link #createInstance(int)}.
+     * If an instance doesnt exist create one with the provided fallback port.
+     *
+     * @return instance of {@link WebSocketServer}
+     */
+    public static WebSocketServer getInstance(final int fallbackPort) {
+        if (instance != null) {
+            return instance;
+        }
+
+        LOG.warn("No instance for WebSocketServer found, creating one with a fallback port: {}", fallbackPort);
+        return createInstance(fallbackPort);
+    }
+
+    /**
+     * Destroy the existing instance.
+     */
+    public static void destroyInstance() {
+        checkState(instance != null, "createInstance() must be called prior to destroyInstance()");
+
+        instance.stop();
+        instance = null;
+        LOG.info("Destroyed WebSocketServer.");
+    }
+
+    @Override
+    @SuppressWarnings("checkstyle:IllegalCatch")
+    public void run() {
+        bossGroup = new NioEventLoopGroup();
+        workerGroup = new NioEventLoopGroup();
+        try {
+            final ServerBootstrap serverBootstrap = new ServerBootstrap();
+            serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)
+                    .childHandler(new WebSocketServerInitializer());
+
+            final Channel channel = serverBootstrap.bind(address, port).sync().channel();
+            LOG.info("Web socket server started at address {}, port {}.", address, port);
+
+            channel.closeFuture().sync();
+        } catch (final InterruptedException e) {
+            LOG.error("Web socket server encountered an error during startup attempt on port {}", port, e);
+        } catch (Throwable throwable) {
+            // sync() re-throws exceptions declared as Throwable, so the compiler doesn't see them
+            LOG.error("Error while binding to address {}, port {}", address, port, throwable);
+            throw throwable;
+        } finally {
+            stop();
+        }
+    }
+
+    /**
+     * Stops the web socket server and removes all listeners.
+     */
+    private void stop() {
+        LOG.info("Stopping the web socket server instance on port {}", port);
+        Notificator.removeAllListeners();
+        if (bossGroup != null) {
+            bossGroup.shutdownGracefully();
+            bossGroup = null;
+        }
+        if (workerGroup != null) {
+            workerGroup.shutdownGracefully();
+            workerGroup = null;
+        }
+    }
+
+}