Added ListenerBoundEvent and ListenerCloseEvent. (#454)

api/src/main/java/com/velocitypowered/api/event/proxy/ListenerBoundEvent.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2018 Velocity Contributors
+ *
+ * The Velocity API is licensed under the terms of the MIT License. For more details,
+ * reference the LICENSE file in the api top-level directory.
+ */
+
+package com.velocitypowered.api.event.proxy;
+
+import com.google.common.base.Preconditions;
+import com.velocitypowered.api.network.ListenerType;
+import java.net.InetSocketAddress;
+
+/**
+ * This event is fired by the proxy after a listener starts accepting connections.
+ */
+public final class ListenerBoundEvent {
+
+  private final InetSocketAddress address;
+  private final ListenerType listenerType;
+
+  public ListenerBoundEvent(InetSocketAddress address, ListenerType listenerType) {
+    this.address = Preconditions.checkNotNull(address, "address");
+    this.listenerType = Preconditions.checkNotNull(listenerType, "listenerType");
+  }
+
+  public InetSocketAddress getAddress() {
+    return address;
+  }
+
+  public ListenerType getListenerType() {
+    return listenerType;
+  }
+
+  @Override
+  public String toString() {
+    return "ListenerBoundEvent{"
+        + "address=" + address
+        + ", listenerType=" + listenerType
+        + '}';
+  }
+}

api/src/main/java/com/velocitypowered/api/event/proxy/ListenerCloseEvent.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2018 Velocity Contributors
+ *
+ * The Velocity API is licensed under the terms of the MIT License. For more details,
+ * reference the LICENSE file in the api top-level directory.
+ */
+
+package com.velocitypowered.api.event.proxy;
+
+import com.google.common.base.Preconditions;
+import com.velocitypowered.api.network.ListenerType;
+import java.net.InetSocketAddress;
+
+/**
+ * This event is fired by the proxy before the proxy stops accepting connections.
+ */
+public final class ListenerCloseEvent {
+
+  private final InetSocketAddress address;
+  private final ListenerType listenerType;
+
+  public ListenerCloseEvent(InetSocketAddress address, ListenerType listenerType) {
+    this.address = Preconditions.checkNotNull(address, "address");
+    this.listenerType = Preconditions.checkNotNull(listenerType, "listenerType");
+  }
+
+  public InetSocketAddress getAddress() {
+    return address;
+  }
+
+  public ListenerType getListenerType() {
+    return listenerType;
+  }
+
+  @Override
+  public String toString() {
+    return "ListenerCloseEvent{"
+        + "address=" + address
+        + ", listenerType=" + listenerType
+        + '}';
+  }
+}

api/src/main/java/com/velocitypowered/api/network/ListenerType.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2018 Velocity Contributors
+ *
+ * The Velocity API is licensed under the terms of the MIT License. For more details,
+ * reference the LICENSE file in the api top-level directory.
+ */
+
+package com.velocitypowered.api.network;
+
+/**
+ * Represents each listener type.
+ */
+public enum ListenerType {
+  MINECRAFT("Minecraft"),
+  QUERY("Query");
+
+  final String name;
+
+  ListenerType(final String name) {
+    this.name = name;
+  }
+
+  @Override
+  public String toString() {
+    return this.name;
+  }
+}

proxy/src/main/java/com/velocitypowered/proxy/network/ConnectionManager.java

@@ -21,6 +21,9 @@ import static org.asynchttpclient.Dsl.asyncHttpClient;
 import static org.asynchttpclient.Dsl.config;
 
 import com.google.common.base.Preconditions;
+import com.velocitypowered.api.event.proxy.ListenerBoundEvent;
+import com.velocitypowered.api.event.proxy.ListenerCloseEvent;
+import com.velocitypowered.api.network.ListenerType;
 import com.velocitypowered.natives.util.Natives;
 import com.velocitypowered.proxy.VelocityServer;
 import com.velocitypowered.proxy.network.netty.SeparatePoolInetNameResolver;
@@ -51,7 +54,7 @@ public final class ConnectionManager {
   private static final WriteBufferWaterMark SERVER_WRITE_MARK = new WriteBufferWaterMark(1 << 20,
       1 << 21);
   private static final Logger LOGGER = LogManager.getLogger(ConnectionManager.class);
-  private final Map<InetSocketAddress, Channel> endpoints = new HashMap<>();
+  private final Map<InetSocketAddress, Endpoint> endpoints = new HashMap<>();
   private final TransportType transportType;
   private final EventLoopGroup bossGroup;
   private final EventLoopGroup workerGroup;
@@ -125,8 +128,12 @@ public final class ConnectionManager {
         .addListener((ChannelFutureListener) future -> {
           final Channel channel = future.channel();
           if (future.isSuccess()) {
-            this.endpoints.put(address, channel);
+            this.endpoints.put(address, new Endpoint(channel, ListenerType.MINECRAFT));
             LOGGER.info("Listening on {}", channel.localAddress());
+
+            // Fire the proxy bound event after the socket is bound
+            server.getEventManager().fireAndForget(
+                new ListenerBoundEvent(address, ListenerType.MINECRAFT));
           } else {
             LOGGER.error("Can't bind to {}", address, future.cause());
           }
@@ -150,8 +157,12 @@ public final class ConnectionManager {
         .addListener((ChannelFutureListener) future -> {
           final Channel channel = future.channel();
           if (future.isSuccess()) {
-            this.endpoints.put(address, channel);
+            this.endpoints.put(address, new Endpoint(channel, ListenerType.QUERY));
             LOGGER.info("Listening for GS4 query on {}", channel.localAddress());
+
+            // Fire the proxy bound event after the socket is bound
+            server.getEventManager().fireAndForget(
+                new ListenerBoundEvent(address, ListenerType.QUERY));
           } else {
             LOGGER.error("Can't bind to {}", bootstrap.config().localAddress(), future.cause());
           }
@@ -185,7 +196,14 @@ public final class ConnectionManager {
    * @param oldBind the endpoint to close
    */
   public void close(InetSocketAddress oldBind) {
-    Channel serverChannel = endpoints.remove(oldBind);
+    Endpoint endpoint = endpoints.remove(oldBind);
+
+    // Fire proxy close event to notify plugins of socket close. We block since plugins
+    // should have a chance to be notified before the server stops accepting connections.
+    server.getEventManager().fire(new ListenerCloseEvent(oldBind, endpoint.getType())).join();
+
+    Channel serverChannel = endpoint.getChannel();
+
     Preconditions.checkState(serverChannel != null, "Endpoint %s not registered", oldBind);
     LOGGER.info("Closing endpoint {}", serverChannel.localAddress());
     serverChannel.close().syncUninterruptibly();
@@ -195,10 +213,17 @@ public final class ConnectionManager {
    * Closes all endpoints.
    */
   public void shutdown() {
-    for (final Channel endpoint : this.endpoints.values()) {
+    for (final Map.Entry<InetSocketAddress, Endpoint> entry : this.endpoints.entrySet()) {
+      final InetSocketAddress address = entry.getKey();
+      final Endpoint endpoint = entry.getValue();
+
+      // Fire proxy close event to notify plugins of socket close. We block since plugins
+      // should have a chance to be notified before the server stops accepting connections.
+      server.getEventManager().fire(new ListenerCloseEvent(address, endpoint.getType())).join();
+
       try {
-        LOGGER.info("Closing endpoint {}", endpoint.localAddress());
+        LOGGER.info("Closing endpoint {}", address);
-        endpoint.close().sync();
+        endpoint.getChannel().close().sync();
       } catch (final InterruptedException e) {
         LOGGER.info("Interrupted whilst closing endpoint", e);
         Thread.currentThread().interrupt();

proxy/src/main/java/com/velocitypowered/proxy/network/Endpoint.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2018 Velocity Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.velocitypowered.proxy.network;
+
+import com.google.common.base.Preconditions;
+import com.velocitypowered.api.network.ListenerType;
+import io.netty.channel.Channel;
+
+/**
+ * Represents a listener endpoint.
+ */
+public final class Endpoint {
+  private final Channel channel;
+  private final ListenerType type;
+
+  public Endpoint(Channel channel, ListenerType type) {
+    this.channel = Preconditions.checkNotNull(channel, "channel");
+    this.type = Preconditions.checkNotNull(type, "type");
+  }
+
+  public Channel getChannel() {
+    return channel;
+  }
+
+  public ListenerType getType() {
+    return type;
+  }
+}