Allow ConfigManager.getConfig... from any thread (copy on write).

This allows fast config getting from any thread, without need to know if
it is the main thread.

NCPCore/src/main/java/fr/neatmonster/nocheatplus/checks/chat/ChatConfig.java

@@ -54,7 +54,7 @@ public static ChatConfig getConfig(final Player player) {
         synchronized (worldsMap) {
             if (!worldsMap.containsKey(player.getWorld().getName()))
                 worldsMap.put(player.getWorld().getName(),
-                        new ChatConfig(ConfigManager.getConfigFileSync(player.getWorld().getName())));
+                        new ChatConfig(ConfigManager.getConfigFile(player.getWorld().getName())));
             return worldsMap.get(player.getWorld().getName());
         }
     }

NCPCore/src/main/java/fr/neatmonster/nocheatplus/config/ConfigManager.java

@@ -3,6 +3,7 @@
 import java.io.File;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Map.Entry;
 
@@ -30,7 +31,7 @@ public final ActionFactory newActionFactory(final Map<String, Object> library) {
     };
 
     /** The map containing the configuration files per world. */
-    private static final Map<String, ConfigFile> worldsMap   = new HashMap<String, ConfigFile>();
+    private static Map<String, ConfigFile> worldsMap = new LinkedHashMap<String, ConfigFile>();
 
     private static final WorldConfigProvider<ConfigFile> worldConfigProvider = new WorldConfigProvider<ConfigFile>() {
 
@@ -118,7 +119,7 @@ public static void cleanup() {
     }
 
     /**
-     * Gets the configuration file.
+     * Gets the configuration file. Can be called from any thread.
      * 
      * @return the configuration file
      */
@@ -129,13 +130,15 @@ public static ConfigFile getConfigFile() {
     /**
      * (Synchronized version).
      * @return
+     * @deprecated getConfigFile() is thread-safe now.
      */
+    @Deprecated
     public static synchronized ConfigFile getConfigFileSync() {
     	return getConfigFile();
     }
 
     /**
-     * Gets the configuration file.
+     * Gets the configuration file. Can be called from any thread.
      * 
      * @param worldName
      *            the world name
@@ -146,14 +149,17 @@ public static ConfigFile getConfigFile(final String worldName) {
         if (configFile != null){
         	return configFile;
         }
-        // Expensive only once, for the rest of runtime the file is returned fast.
+        // Expensive only once per world, for the rest of the runtime the file is returned fast.
     	synchronized(ConfigManager.class){
     		// Need to check again.
     		if (worldsMap.containsKey(worldName)){
     			return worldsMap.get(worldName);
     		}
-    		final ConfigFile globalConfig = getConfigFile();
-    		worldsMap.put(worldName, globalConfig);
+    		// Copy the whole map with the default configuration set for this world.
+    		final Map<String, ConfigFile> newWorldsMap = new LinkedHashMap<String, ConfigFile>(ConfigManager.worldsMap);
+    		final ConfigFile globalConfig = newWorldsMap.get(null);
+    		newWorldsMap.put(worldName, globalConfig);
+    		ConfigManager.worldsMap = newWorldsMap;
     		return globalConfig;
     	}
     }
@@ -162,13 +168,15 @@ public static ConfigFile getConfigFile(final String worldName) {
      * (Synchronized version).
      * @param worldName
      * @return
+     * @deprecated getConfigFile() is thread-safe now.
      */
+    @Deprecated
     public static synchronized ConfigFile getConfigFileSync(final String worldName) {
     	return getConfigFile(worldName);
     }
 
     /**
-     * Initializes the configuration manager.
+     * Initializes the configuration manager. Must be called in the main thread.
      * 
      * @param plugin
      *            the instance of NoCheatPlus