Waterfall/BungeeCord-Patches/0026-Add-dynamic-server-addition-removal-api.patch

From 9ece9eee1db885737f55a9215fd014c1664f7ccf Mon Sep 17 00:00:00 2001
From: Troy Frew <fuzzy_bot@arenaga.me>
Date: Wed, 29 Jun 2016 04:29:25 +0200
Subject: [PATCH] Add dynamic server addition/removal api.

The provided methods will not move a player if a server is removed or the server ip/port is changed, however the methods return the old ServerInfo object for you to handle that yourself if needed.

Thanks to Overcast for the idea

diff --git a/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java b/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java
index 1f643980..dc4d609f 100644
--- a/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java
+++ b/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java
@@ -31,9 +31,95 @@ public interface ProxyConfig
 
     /**
      * Set of all servers.
+     *
+     * @deprecated The returned map may be modified concurrently by the proxy.
+     *             The safe alternative is {@link #getServersCopy()}.
      */
+    @Deprecated // Waterfall
     Map<String, ServerInfo> getServers();
 
+    // Waterfall start - Dynamic server addition/removal api
+    /**
+     * Return all servers registered to this proxy, keyed by name. The returned map
+     * is an immutable snapshot of the actual server collection. It cannot be modified,
+     * and it will not change.
+     *
+     * @return all registered remote server destinations
+     */
+    Map<String, ServerInfo> getServersCopy();
+
+    /**
+     * Gets the server info of a server.
+     *
+     * @param name the name of the configured server
+     * @return the server info belonging to the specified server
+     */
+    ServerInfo getServerInfo(String name);
+
+    /**
+     * Register the given server to the proxy.
+     * Any currently registered server with the same name will be replaced.
+     * This change is not saved to config.yml
+     *
+     * @param server The server to register with the proxy
+     *
+     * @return the previously registered server with the same name, or null if there was no such server.
+     */
+    ServerInfo addServer(ServerInfo server);
+
+    /**
+     * Register all of the given servers to the proxy.
+     * This change is not saved to config.yml
+     *
+     * @param servers The collection of servers to register with the proxy
+     *
+     * @return true if any servers were added or replaced.
+     */
+    boolean addServers(Collection<ServerInfo> servers);
+
+    /**
+     * Un-register the server with the given name from the proxy.
+     * This change is not saved to config.yml
+     *
+     * @param name The name of the server to unregister
+     *
+     * @return the server that was removed, or null if there is no server with the given name.
+     */
+    ServerInfo removeServerNamed(String name);
+
+    /**
+     * Un-register the given server from the proxy.
+     * The server is matched by name only, other fields in the given {@link ServerInfo} are ignored.
+     * This change is not saved to config.yml
+     *
+     * @param server the server to unregister from the proxy
+     *
+     * @return the server that was removed, or null if there is no server with a matching name.
+     */
+    ServerInfo removeServer(ServerInfo server);
+
+    /**
+     * Un-register servers with any of the given names from the proxy.
+     * This change is not saved to config.yml
+     *
+     * @param names a collection of server names to be unregistered
+     *
+     * @return true if any servers were removed.
+     */
+    boolean removeServersNamed(Collection<String> names);
+
+    /**
+     * Un-register all of the given servers from the proxy.
+     * The servers are matched by name only, other fields in the given {@link ServerInfo} are ignored.
+     * This change is not saved to config.yml
+     *
+     * @param servers a collection of servers to be unregistered
+     *
+     * @return true if any servers were removed.
+     */
+    boolean removeServers(Collection<ServerInfo> servers);
+    // Waterfall end
+
     /**
      * Does the server authenticate with mojang
      */
diff --git a/api/src/main/java/net/md_5/bungee/api/ProxyServer.java b/api/src/main/java/net/md_5/bungee/api/ProxyServer.java
index 15bea8fe..1c8e9eda 100644
--- a/api/src/main/java/net/md_5/bungee/api/ProxyServer.java
+++ b/api/src/main/java/net/md_5/bungee/api/ProxyServer.java
@@ -93,9 +93,25 @@ public abstract class ProxyServer
      * return a fresh map each time.
      *
      * @return all registered remote server destinations
+     *
+     * @deprecated The returned map is part of the proxy's internal state,
+     *             and may be modified concurrently by the proxy.
+     *             The safe alternative is {@link #getServersCopy()}.
      */
+    @Deprecated // Waterfall
     public abstract Map<String, ServerInfo> getServers();
 
+    // Waterfall begin - Cloned servers map
+    /**
+     * Return all servers registered to this proxy, keyed by name. The returned map
+     * is an immutable snapshot of the actual server collection. It cannot be modified,
+     * and it will not change.
+     *
+     * @return all registered remote server destinations
+     */
+    public abstract Map<String, ServerInfo> getServersCopy();
+    // Waterfall end
+
     /**
      * Gets the server info of a server.
      *
diff --git a/config/src/main/java/net/md_5/bungee/config/Configuration.java b/config/src/main/java/net/md_5/bungee/config/Configuration.java
index 262b29c8..d7ed3e11 100644
--- a/config/src/main/java/net/md_5/bungee/config/Configuration.java
+++ b/config/src/main/java/net/md_5/bungee/config/Configuration.java
@@ -44,6 +44,13 @@ public final class Configuration
         }
     }
 
+    // Waterfall start - Allow configuration objects to be cloned
+    public Configuration(Configuration values, Configuration defaults)
+    {
+        this( values.self, defaults );
+    }
+    // Waterfall end
+
     private Configuration getSectionFor(String path)
     {
         int index = path.indexOf( SEPARATOR );
diff --git a/module/cmd-server/src/main/java/net/md_5/bungee/module/cmd/server/CommandServer.java b/module/cmd-server/src/main/java/net/md_5/bungee/module/cmd/server/CommandServer.java
index 9693701d..3fdd9949 100644
--- a/module/cmd-server/src/main/java/net/md_5/bungee/module/cmd/server/CommandServer.java
+++ b/module/cmd-server/src/main/java/net/md_5/bungee/module/cmd/server/CommandServer.java
@@ -83,7 +83,7 @@ public class CommandServer extends Command implements TabExecutor
     @Override
     public Iterable<String> onTabComplete(final CommandSender sender, final String[] args)
     {
-        return ( args.length > 1 ) ? Collections.EMPTY_LIST : Iterables.transform( Iterables.filter( ProxyServer.getInstance().getServers().values(), new Predicate<ServerInfo>()
+        return ( args.length > 1 ) ? Collections.EMPTY_LIST : Iterables.transform( Iterables.filter( ProxyServer.getInstance().getServersCopy().values(), new Predicate<ServerInfo>() // Waterfall: use #getServersCopy()
         {
             private final String lower = ( args.length == 0 ) ? "" : args[0].toLowerCase( Locale.ROOT );
 
diff --git a/proxy/src/main/java/net/md_5/bungee/BungeeCord.java b/proxy/src/main/java/net/md_5/bungee/BungeeCord.java
index 83a300dc..0ff6781c 100644
--- a/proxy/src/main/java/net/md_5/bungee/BungeeCord.java
+++ b/proxy/src/main/java/net/md_5/bungee/BungeeCord.java
@@ -596,10 +596,18 @@ public class BungeeCord extends ProxyServer
         return config.getServers();
     }
 
+    // Waterfall start
+    @Override
+    public Map<String, ServerInfo> getServersCopy()
+    {
+        return config.getServersCopy();
+    }
+    // Waterfall end
+
     @Override
     public ServerInfo getServerInfo(String name)
     {
-        return getServers().get( name );
+        return config.getServerInfo( name ); // Waterfall
     }
 
     @Override
diff --git a/proxy/src/main/java/net/md_5/bungee/conf/Configuration.java b/proxy/src/main/java/net/md_5/bungee/conf/Configuration.java
index 193d8bce..2ec6c23c 100644
--- a/proxy/src/main/java/net/md_5/bungee/conf/Configuration.java
+++ b/proxy/src/main/java/net/md_5/bungee/conf/Configuration.java
@@ -1,6 +1,7 @@
 package net.md_5.bungee.conf;
 
 import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap; // Waterfall
 import gnu.trove.map.TMap;
 import java.io.File;
 import java.io.IOException;
@@ -11,6 +12,7 @@ import java.util.UUID;
 import java.util.logging.Level;
 import javax.imageio.ImageIO;
 import lombok.Getter;
+import lombok.Synchronized; // Waterfall
 
 import net.md_5.bungee.BungeeCord;
 import net.md_5.bungee.api.Favicon;
@@ -42,6 +44,7 @@ public abstract class Configuration implements ProxyConfig
      * Set of all listeners.
      */
     private Collection<ListenerInfo> listeners;
+    private final Object serversLock = new Object(); // Waterfall
     /**
      * Set of all servers.
      */
@@ -65,6 +68,7 @@ public abstract class Configuration implements ProxyConfig
     private boolean preventProxyConnections;
     private boolean forgeSupport;
 
+    @Synchronized("serversLock") // Waterfall
     public void load()
     {
         ConfigurationAdapter adapter = ProxyServer.getInstance().getConfigurationAdapter();
@@ -108,7 +112,7 @@ public abstract class Configuration implements ProxyConfig
             servers = new CaseInsensitiveMap<>( newServers );
         } else
         {
-            Map<String, ServerInfo> oldServers = this.servers;
+            Map<String, ServerInfo> oldServers = getServersCopy();
 
             for ( ServerInfo oldServer : oldServers.values() )
             {
@@ -171,4 +175,71 @@ public abstract class Configuration implements ProxyConfig
     {
         return favicon;
     }
+
+    // Waterfall start
+    @Override
+    @Synchronized("serversLock")
+    public Map<String, ServerInfo> getServersCopy() {
+        return ImmutableMap.copyOf( servers );
+    }
+
+    @Override
+    @Synchronized("serversLock")
+    public ServerInfo getServerInfo(String name)
+    {
+        return this.servers.get( name );
+    }
+
+    @Override
+    @Synchronized("serversLock")
+    public ServerInfo addServer(ServerInfo server)
+    {
+        return this.servers.put( server.getName(), server );
+    }
+
+    @Override
+    @Synchronized("serversLock")
+    public boolean addServers(Collection<ServerInfo> servers)
+    {
+        boolean changed = false;
+        for ( ServerInfo server : servers )
+        {
+            if ( server != this.servers.put( server.getName(), server ) ) changed = true;
+        }
+        return changed;
+    }
+
+    @Override
+    @Synchronized("serversLock")
+    public ServerInfo removeServerNamed(String name)
+    {
+        return this.servers.remove( name );
+    }
+
+    @Override
+    @Synchronized("serversLock")
+    public ServerInfo removeServer(ServerInfo server)
+    {
+        return this.servers.remove( server.getName() );
+    }
+
+    @Override
+    @Synchronized("serversLock")
+    public boolean removeServersNamed(Collection<String> names)
+    {
+        return this.servers.keySet().removeAll( names );
+    }
+
+    @Override
+    @Synchronized("serversLock")
+    public boolean removeServers(Collection<ServerInfo> servers)
+    {
+        boolean changed = false;
+        for ( ServerInfo server : servers )
+        {
+            if ( null != this.servers.remove( server.getName() ) ) changed = true;
+        }
+        return changed;
+    }
+    // Waterfall end
 }
-- 
2.21.0