From 3f417d8ecb6fd00f8fd713e2cce59e24c1e50652 Mon Sep 17 00:00:00 2001
From: Lixfel <agga-games@gmx.de>
Date: Sat, 2 Oct 2021 19:07:50 +0200
Subject: [PATCH] Cyclic port running to reduce failing server starts

Signed-off-by: Lixfel <agga-games@gmx.de>
---
 .../steamwar/bungeecore/SubserverSystem.java  | 68 ++++++++++++-------
 1 file changed, 42 insertions(+), 26 deletions(-)

diff --git a/src/de/steamwar/bungeecore/SubserverSystem.java b/src/de/steamwar/bungeecore/SubserverSystem.java
index 018c8a3..66ec037 100644
--- a/src/de/steamwar/bungeecore/SubserverSystem.java
+++ b/src/de/steamwar/bungeecore/SubserverSystem.java
@@ -29,7 +29,9 @@ import net.md_5.bungee.api.connection.ProxiedPlayer;
 import java.io.File;
 import java.net.InetSocketAddress;
 import java.time.format.DateTimeFormatter;
+import java.util.Set;
 import java.util.UUID;
+import java.util.stream.Collectors;
 
 public class SubserverSystem {
     private SubserverSystem(){}
@@ -39,14 +41,9 @@ public class SubserverSystem {
     private static final String SERVER_PATH = BACKBONE + "server/";
     private static final String EVENT_PATH = BACKBONE + "event/";
 
-    private static final int FIRST_ARENA_PORT;
-
-    static {
-        if(BungeeCore.EVENT_MODE)
-            FIRST_ARENA_PORT = 6000;
-        else
-            FIRST_ARENA_PORT = 2500;
-    }
+    private static final boolean MAIN_SERVER = ProxyServer.getInstance().getConfig().getListeners().stream().anyMatch(info -> ((InetSocketAddress) info.getSocketAddress()).getPort() == 25565);
+    private static final Portrange bauPorts = MAIN_SERVER ? new Portrange(10100, 20000) : new Portrange(2100, 2200);
+    private static final Portrange arenaPorts = MAIN_SERVER ? new Portrange(3000, 3100) : (BungeeCore.EVENT_MODE ? new Portrange(4000, 5000) : bauPorts);
 
     /**
      * This function starts every arena (even test- and eventarenas).
@@ -88,13 +85,13 @@ public class SubserverSystem {
     public static synchronized Subserver startArena(ArenaMode modus, String map, int eventFightID, int checkSchemID, int prepareSchemID, String serverName, String mapName, UUID player1, UUID player2, boolean ranked){
         //Generate missing parameters
         Node node = eventFightID > 0 ? Node.local : Node.getNode();
-        int port = freePort(FIRST_ARENA_PORT);
+        int port = arenaPorts.freePort();
 
         if(serverName == null){
             if(ranked)
-                serverName = "Ranked" + (port - FIRST_ARENA_PORT);
+                serverName = "Ranked" + (port - arenaPorts.start);
             else
-                serverName = modus.getDisplayName() + (port - FIRST_ARENA_PORT);
+                serverName = modus.getDisplayName() + (port - arenaPorts.start);
         }
         if(mapName == null)
             mapName = serverName;
@@ -159,7 +156,7 @@ public class SubserverSystem {
         SteamwarUser user = SteamwarUser.get(owner);
         File directory = new File(SERVER_PATH, serverName);
         Node node = Node.getNode();
-        int port = freePort(4000);
+        int port = bauPorts.freePort();
 
         new Bauserver(user.getUserName() + "s Bau", owner, port, node.startServer(
                 serverJar, directory, worldDir, worldName, port, xmx, "logPath=" + worldName
@@ -213,21 +210,40 @@ public class SubserverSystem {
             Node.local.execute("cp", "-r", sourcePath, targetPath);
     }
 
-    private static int freePort(int start){
-        synchronized (Subserver.getServerList()){
-            int port = start;
-            boolean isFree = false;
-            while(!isFree){
-                port++;
-                isFree = true;
-                for(Subserver server : Subserver.getServerList()){
-                    if(((InetSocketAddress)server.getServer().getSocketAddress()).getPort() == port){
-                        isFree = false;
-                        break;
-                    }
-                }
+
+    private static class Portrange {
+
+        private final int start;
+        private final int end;
+        private int current;
+
+        private Portrange(int start, int end) {
+            this.start = start;
+            this.end = end;
+            current = start;
+        }
+
+        private void increment() {
+            current++;
+
+            if(current == end)
+                current = start;
+        }
+
+        private synchronized int freePort() {
+            Set<Integer> usedPorts;
+
+            synchronized (Subserver.getServerList()) {
+                usedPorts = Subserver.getServerList().stream().map(server -> ((InetSocketAddress) server.getServer().getSocketAddress()).getPort()).collect(Collectors.toSet());
             }
-            return port;
+
+            while(usedPorts.contains(current)) {
+                increment();
+            }
+
+            int result = current;
+            increment();
+            return result;
         }
     }
 }