Checkpointing support

build.gradle

@@ -32,8 +32,8 @@ mainClassName = ''
 
 compileJava.options.encoding = 'UTF-8'
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
+sourceCompatibility = 1.11
+targetCompatibility = 1.11
 
 sourceSets {
     main {

src/de/steamwar/bungeecore/Arenaserver.java

@@ -1,5 +1,8 @@
 package de.steamwar.bungeecore;
 
+import lombok.Getter;
+
+@Getter
 public class Arenaserver extends Subserver {
 
     private final String mode;
@@ -13,15 +16,4 @@ public class Arenaserver extends Subserver {
         this.allowMerge = allowMerge;
     }
 
-    public String getMode() {
-        return mode;
-    }
-
-    public String getMap() {
-        return map;
-    }
-
-    public boolean isAllowMerge() {
-        return allowMerge;
-    }
 }

src/de/steamwar/bungeecore/Bauserver.java

@@ -19,26 +19,41 @@
 
 package de.steamwar.bungeecore;
 
+import lombok.Getter;
+
+import java.util.HashMap;
+import java.util.Map;
 import java.util.UUID;
 
+@Getter
 public class Bauserver extends Subserver {
+    private static final Map<UUID, Bauserver> servers = new HashMap<>();
+    public static Bauserver get(UUID owner) {
+        synchronized (servers) {
+            return servers.get(owner);
+        }
+    }
 
     private final UUID owner;
 
-    public Bauserver(String serverName, UUID owner, int port, String... command) {
-        this(serverName, owner, port, () -> {}, command);
-    }
-
-    public Bauserver(String serverName, UUID owner, int port, Runnable shutdownCallback, String... command) {
-        this(serverName, owner, port, new ProcessBuilder(command), shutdownCallback);
-    }
-
     public Bauserver(String serverName, UUID owner, int port, ProcessBuilder processBuilder, Runnable shutdownCallback){
         super(Servertype.BAUSERVER, serverName, port, processBuilder, shutdownCallback);
         this.owner = owner;
     }
 
-    public UUID getOwner(){
-        return owner;
+    @Override
+    protected void register() {
+        super.register();
+        synchronized (servers) {
+            servers.put(owner, this);
+        }
+    }
+
+    @Override
+    protected void unregister() {
+        synchronized (servers) {
+            servers.remove(owner);
+        }
+        super.unregister();
     }
 }

src/de/steamwar/bungeecore/Builderserver.java

@@ -19,8 +19,21 @@
 
 package de.steamwar.bungeecore;
 
+import lombok.Getter;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Getter
 public class Builderserver extends Subserver {
 
+    private static final Map<String, Builderserver> servers = new HashMap<>();
+    public static Builderserver get(String map) {
+        synchronized (servers) {
+            return servers.get(map);
+        }
+    }
+
     private final String map;
 
     public Builderserver(String serverName, String map, int port, ProcessBuilder processBuilder, Runnable shutdownCallback){
@@ -28,7 +41,19 @@ public class Builderserver extends Subserver {
         this.map = map;
     }
 
-    public String getMap() {
-        return map;
+    @Override
+    protected void register() {
+        super.register();
+        synchronized (servers) {
+            servers.put(map, this);
+        }
+    }
+
+    @Override
+    protected void unregister() {
+        synchronized (servers) {
+            servers.remove(map);
+        }
+        super.unregister();
     }
 }

src/de/steamwar/bungeecore/Subserver.java

@@ -19,6 +19,7 @@
 
 package de.steamwar.bungeecore;
 
+import lombok.Getter;
 import net.md_5.bungee.api.ChatMessageType;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.api.chat.BaseComponent;
@@ -26,26 +27,29 @@ import net.md_5.bungee.api.chat.TextComponent;
 import net.md_5.bungee.api.config.ServerInfo;
 import net.md_5.bungee.api.connection.ProxiedPlayer;
 
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.PrintWriter;
+import java.io.*;
 import java.net.InetSocketAddress;
 import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-@SuppressWarnings("deprecation")
-public class Subserver implements Runnable {
+public class Subserver {
 
-    private static final List<Subserver> serverList = new LinkedList<>();
+    @SuppressWarnings("deprecation")
+    private static final Map<String, ServerInfo> servers = ProxyServer.getInstance().getServers();
     private static final Logger logger = ProxyServer.getInstance().getLogger();
 
-    public static Subserver getSubserver(ProxiedPlayer p){
+    @Getter
+    private static final List<Subserver> serverList = new LinkedList<>();
+    private static final Map<ServerInfo, Subserver> infoToServer = new HashMap<>();
+
+    public static Subserver getSubserver(ProxiedPlayer p) {
         synchronized (serverList) {
             for(int i = serverList.size()-1; i >= 0; i--){
                 if(serverList.get(i).onServer(p))
@@ -54,43 +58,49 @@ public class Subserver implements Runnable {
         }
         return null;
     }
-    public static Subserver getSubserver(ServerInfo server){
+
+    public static Subserver getSubserver(ServerInfo server) {
         synchronized (serverList) {
-            for(Subserver s : serverList)
-                if(s.server == server)
-                    return s;
+            return infoToServer.get(server);
         }
-        return null;
     }
-    public static List<Subserver> getServerList(){
-        return serverList;
+
+    static void shutdown(){
+        while (!serverList.isEmpty()) {
+            Subserver server = serverList.get(0);
+            server.stop();
+        }
     }
 
     private final String serverName;
+    private final boolean checkpoint;
     private final Runnable shutdownCallback;
+    private final Consumer<Exception> failureCallback;
     private final Process process;
     private final PrintWriter writer;
+    @Getter
     private final ServerInfo server;
+    @Getter
     private final Servertype type;
     private final Thread thread;
+    @Getter
     private boolean started;
 
     private final List<ProxiedPlayer> cachedPlayers = new LinkedList<>();
+    @Getter
     private final Map<ProxiedPlayer, String> tablistNames = new HashMap<>();
 
-    public Subserver(Servertype type, String serverName, int port, String... command){
-        this(type, serverName, port, () -> {}, command);
-    }
-
-    public Subserver(Servertype type, String serverName, int port, Runnable shutdownCallback, String... command){
-        this(type, serverName, port, new ProcessBuilder(command), shutdownCallback);
-    }
-
     public Subserver(Servertype type, String serverName, int port, ProcessBuilder processBuilder, Runnable shutdownCallback){
+        this(type, serverName, port, processBuilder, shutdownCallback, null);
+    }
+
+    public Subserver(Servertype type, String serverName, int port, ProcessBuilder processBuilder, Runnable shutdownCallback, Consumer<Exception> failureCallback) {
         this.started = false;
         this.serverName = serverName;
         this.type = type;
         this.shutdownCallback = shutdownCallback;
+        this.failureCallback =  failureCallback == null ? this::fatalError : failureCallback;
+        this.checkpoint = processBuilder.command().contains("criu");
 
         try{
             this.process = processBuilder.start();
@@ -103,27 +113,18 @@ public class Subserver implements Runnable {
                 serverName, address, "SteamWar.de - Subserver", false);
         this.writer = new PrintWriter(process.getOutputStream(), true);
 
-        this.thread = new Thread(this, "Subserver " + serverName);
+        this.thread = new Thread(this::run, "Subserver " + serverName);
         this.thread.start();
     }
 
-    public ServerInfo getServer(){
-        return server;
-    }
-    public Servertype getType(){
-        return type;
-    }
-    public Map<ProxiedPlayer, String> getTablistNames(){
-        return tablistNames;
-    }
-
+    @Deprecated
     public boolean hasStarted(){
         return started;
     }
 
-    public void sendPlayer(ProxiedPlayer p){
+    public void sendPlayer(ProxiedPlayer p) {
         if(!started){
-            p.sendMessage(Persistent.PREFIX + "§7Starting server, please wait...");
+            p.sendMessage(ChatMessageType.ACTION_BAR, generateBar(0));
             cachedPlayers.add(p);
         }else{
             p.connect(server);
@@ -134,11 +135,16 @@ public class Subserver implements Runnable {
         writer.println(command);
     }
 
-    public void stop(){
-        execute("stop");
+    public void stop() {
+        if(checkpoint)
+            process.children().forEach(ProcessHandle::destroy);
+        else
+            execute("stop");
+
         try {
             if(!process.waitFor(1, TimeUnit.MINUTES))
                 process.destroyForcibly();
+
             thread.join();
         }catch(InterruptedException e){
             logger.log(Level.SEVERE, "Subserver stop interrupted!", e);
@@ -146,98 +152,99 @@ public class Subserver implements Runnable {
         }
     }
 
-    public void waitForTermination(){
-        try {
-            if(!process.waitFor(5, TimeUnit.MINUTES) && server.getPlayers().isEmpty()){
-                process.destroy();
-            }
-            thread.join();
-        }catch(InterruptedException e){
-            logger.log(Level.SEVERE, "Subserver stop interrupted!", e);
-            Thread.currentThread().interrupt();
-        }
-    }
-
-    static void shutdown(){
-        while (!serverList.isEmpty()) {
-            Subserver server = serverList.get(0);
-            server.stop();
-        }
-    }
-
     private boolean onServer(ProxiedPlayer p){
         return cachedPlayers.contains(p) || server.getPlayers().contains(p);
     }
 
-    private void fatalError(){
+    private void fatalError(Exception e) {
+        logger.log(Level.SEVERE, e, () -> serverName + " did not run correctly!");
+
         for(ProxiedPlayer cached : cachedPlayers)
-            cached.sendMessage(Persistent.PREFIX + "§cUnexpected error during server startup.");
+            cached.sendMessage(TextComponent.fromLegacy(Persistent.PREFIX + "§cUnexpected error during server startup."));
         for(ProxiedPlayer player : server.getPlayers())
-            player.sendMessage(Persistent.PREFIX + "§cLost connection to server.");
+            player.sendMessage(TextComponent.fromLegacy(Persistent.PREFIX + "§cLost connection to server."));
     }
 
-    private void sendProgress(int progress){
-        StringBuilder sb = new StringBuilder("§e");
-        for(int i = 0; i < progress; i++)
-            sb.append('⬛');
-        sb.append("§8");
-        for(int i = progress; i < 10; i++)
-            sb.append('⬛');
-
-        BaseComponent[] tc = TextComponent.fromLegacyText(sb.toString());
-        for(ProxiedPlayer cached : cachedPlayers)
-            cached.sendMessage(ChatMessageType.ACTION_BAR, tc);
-    }
-
-    public void run(){
-        ProxyServer.getInstance().getServers().put(serverName, server);
-        synchronized (serverList) {
-            serverList.add(this);
-        }
-
-        try(BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()))){
+    private void start(InputStream stream, Predicate<String> test) throws IOException {
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream))) {
             String line = "";
             while (!started && (line = reader.readLine()) != null) {
-                started = line.contains("ViaVersion detected server version");
-                if(line.contains("Loading libraries, please wait"))
-                    sendProgress(0);
-                else if(line.contains("Starting Minecraft server on"))
-                    sendProgress(3);
-                else if(line.contains("Preparing start region"))
-                    sendProgress(6);
+                started = test.test(line);
             }
 
             if(line == null){
-                logger.log(Level.SEVERE, "Subserver {0} stopped to early!",  serverName);
-                fatalError();
-                return;
+                failureCallback.accept(new IOException(serverName + " did not start correctly!"));
+                started = false;
+            }
+        }
+    }
+
+    protected void register() {
+        servers.put(serverName, server);
+        synchronized (serverList) {
+            serverList.add(this);
+            infoToServer.put(server, this);
+        }
+    }
+
+    protected void unregister() {
+        synchronized (serverList){
+            infoToServer.remove(server);
+            serverList.remove(this);
+        }
+        servers.remove(serverName);
+    }
+
+    private void run() {
+        register();
+
+        try {
+            if(checkpoint) {
+                start(process.getErrorStream(), line -> line.contains("Restore finished successfully."));
+            } else {
+                start(process.getInputStream(), line -> {
+                    if(line.contains("Loading libraries, please wait"))
+                        sendProgress(2);
+                    else if(line.contains("Starting Minecraft server on"))
+                        sendProgress(4);
+                    else if(line.contains("Preparing start region"))
+                        sendProgress(6);
+                    return line.contains("Done (");
+                });
             }
 
-            sendProgress(9);
+            if(!started)
+                return;
+
+            sendProgress(8);
 
             Thread.sleep(300);
 
             sendProgress(10);
-            for(ProxiedPlayer cachedPlayer : cachedPlayers){
+            for(ProxiedPlayer cachedPlayer : cachedPlayers) {
                 sendPlayer(cachedPlayer);
             }
             cachedPlayers.clear();
 
-            reader.close(); // Prevent stdout clogging up
             process.waitFor();
         } catch(IOException e) {
-            logger.log(Level.SEVERE, "Server " + serverName + " was interrupted!", e);
-            fatalError();
+            failureCallback.accept(e);
         } catch(InterruptedException e) {
-            logger.log(Level.SEVERE, "Server " + serverName + " was interrupted!", e);
-            fatalError();
+            failureCallback.accept(e);
             Thread.currentThread().interrupt();
         } finally {
-            synchronized (serverList){
-                serverList.remove(this);
-            }
-            ProxyServer.getInstance().getServers().remove(serverName);
             shutdownCallback.run();
+            unregister();
         }
     }
+
+    private BaseComponent generateBar(int progress) {
+        return TextComponent.fromLegacy("§e" + "⬛".repeat(Math.max(0, progress)) + "§8" + "⬛".repeat(Math.max(0, 10 - progress)));
+    }
+
+    private void sendProgress(int progress) {
+        BaseComponent tc = generateBar(progress);
+        for(ProxiedPlayer cached : cachedPlayers)
+            cached.sendMessage(ChatMessageType.ACTION_BAR, tc);
+    }
 }