Added Patch-Function for *level.dat *

src/main/java/ru/bclib/api/datafixer/DataFixerAPI.java

@@ -22,6 +22,9 @@ import java.util.regex.Pattern;
 
 public class DataFixerAPI {
 	static final Logger LOGGER = new Logger("DataFixerAPI");
+	static class State {
+		public boolean didFail = false;
+	}
 	
 	public static void fixData(File dir) {
 		if (!Configs.MAIN_CONFIG.getBoolean(Configs.MAIN_PATCH_CATEGORY, "applyPatches", true)) {
@@ -36,22 +39,22 @@ public class DataFixerAPI {
 			return;
 		}
 
-		boolean[] allOk = {true};
+		State state = new State();
 		
 		List<File> regions = getAllRegions(dir, null);
-		regions.parallelStream().forEach((file) -> fixRegion(data, allOk, file));
+		regions.parallelStream().forEach((file) -> fixRegion(data, state, file));
 
 		List<File> players = getAllPlayers(dir);
-		players.parallelStream().forEach((file) -> fixPlayer(data, allOk, file));
+		players.parallelStream().forEach((file) -> fixPlayer(data, state, file));
 
-		fixLevel(data, allOk, new File(dir, "level.dat"));
+		fixLevel(data, state, new File(dir, "level.dat"));
 		
-		if (allOk[0]) {
+		if (!state.didFail) {
 			data.markApplied();
 			WorldDataAPI.saveFile(BCLib.MOD_ID);
 		}
 	}
-	private static void fixLevel(MigrationProfile data, boolean[] allOk, File file) {
+	private static void fixLevel(MigrationProfile data, State state, File file) {
 		try {
 			LOGGER.info("Inspecting " + file);
 			CompoundTag level = NbtIo.readCompressed(file);
@@ -64,6 +67,13 @@ public class DataFixerAPI {
 					fixPlayerNbt(player, changed, data);
 				}
 			}
+			
+			try {
+				changed[0] |= data.patchLevelDat(level);
+			} catch (PatchDidiFailException e){
+				state.didFail = true;
+				BCLib.LOGGER.error(e.getMessage());
+			}
 
 			if (changed[0]) {
 				LOGGER.warning("Writing '{}'", file);
@@ -71,12 +81,13 @@ public class DataFixerAPI {
 			}
 		}
 		catch (Exception e) {
-			allOk[0] = false;
+			BCLib.LOGGER.error("Failed fixing Level-Data.");
+			state.didFail = true;
 			e.printStackTrace();
 		}
 	}
 
-	private static void fixPlayer(MigrationProfile data, boolean[] allOk, File file) {
+	private static void fixPlayer(MigrationProfile data, State state, File file) {
 		try {
 			LOGGER.info("Inspecting " + file);
 			CompoundTag player = NbtIo.readCompressed(file);
@@ -89,7 +100,8 @@ public class DataFixerAPI {
 			}
 		}
 		catch (Exception e) {
-			allOk[0] = false;
+			BCLib.LOGGER.error("Failed fixing Player-Data.");
+			state.didFail = true;
 			e.printStackTrace();
 		}
 	}
@@ -104,7 +116,7 @@ public class DataFixerAPI {
 		fixInventory(enderitems, changed, data, true);
 	}
 
-	private static void fixRegion(MigrationProfile data, boolean[] allOk, File file) {
+	private static void fixRegion(MigrationProfile data, State state, File file) {
 		try {
 			LOGGER.info("Inspecting " + file);
 			boolean[] changed = new boolean[1];
@@ -155,7 +167,8 @@ public class DataFixerAPI {
 			region.close();
 		}
 		catch (Exception e) {
-			allOk[0] = false;
+			BCLib.LOGGER.error("Failed fixing Player Data.");
+			state.didFail = true;
 			e.printStackTrace();
 		}
 	}

src/main/java/ru/bclib/api/datafixer/MigrationProfile.java

@@ -5,6 +5,8 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -12,6 +14,8 @@ import java.util.stream.Collectors;
 class MigrationProfile {
 	final Set<String> mods;
 	final Map<String, String> idReplacements;
+	final List<PatchFunction<CompoundTag, Boolean>> levelPatchers;
+	
 	private final CompoundTag config;
 	
 	MigrationProfile(CompoundTag config) {
@@ -23,6 +27,7 @@ class MigrationProfile {
 													 .collect(Collectors.toSet()));
 		
 		HashMap<String, String> replacements = new HashMap<String, String>();
+		List<PatchFunction<CompoundTag, Boolean>> levelPatches = new LinkedList<>();
 		for (String modID : mods) {
 			Patch.getALL()
 				 .stream()
@@ -30,6 +35,8 @@ class MigrationProfile {
 				 .forEach(patch -> {
 					 if (currentPatchLevel(modID) < patch.level) {
 						 replacements.putAll(patch.getIDReplacements());
+						 if (patch.getLevelDatPatcher()!=null)
+							 levelPatches.add(patch.getLevelDatPatcher());
 						 DataFixerAPI.LOGGER.info("Applying " + patch);
 					 }
 					 else {
@@ -39,6 +46,7 @@ class MigrationProfile {
 		}
 		
 		this.idReplacements = Collections.unmodifiableMap(replacements);
+		this.levelPatchers = Collections.unmodifiableList(levelPatches);
 	}
 	
 	final public void markApplied() {
@@ -58,7 +66,7 @@ class MigrationProfile {
 	}
 	
 	public boolean hasAnyFixes() {
-		return idReplacements.size() > 0;
+		return idReplacements.size() > 0 || levelPatchers.size() > 0;
 	}
 	
 	public boolean replaceStringFromIDs(@NotNull CompoundTag tag, @NotNull String key) {
@@ -75,4 +83,12 @@ class MigrationProfile {
 		
 		return false;
 	}
+	
+	public boolean patchLevelDat(@NotNull CompoundTag level) throws PatchDidiFailException {
+		boolean changed = false;
+		for (PatchFunction<CompoundTag, Boolean> f : levelPatchers) {
+			changed |= f.apply(level);
+		}
+		return changed;
+	}
 }

src/main/java/ru/bclib/api/datafixer/Patch.java

@@ -9,6 +9,7 @@ import java.util.List;
 import java.util.Map;
 
 public abstract class Patch {
+	
 	private static List<Patch> ALL = new ArrayList<>(10);
 	
 	/**
@@ -119,6 +120,19 @@ public abstract class Patch {
 		return new HashMap<String, String>();
 	}
 	
+	/**
+	 * Return a {@link PatchFunction} that is called with the content of <i>level.dat</i>.
+	 * <p>
+	 * The function needs to return {@code true}, if changes were made to the data.
+	 * If an error occurs, the method shoudl throw a {@link PatchDidiFailException}
+	 *
+	 * The default implementation of this method returns null.
+	 *
+	 * @return The returned function is called a {@code CompoundTag} that contains the
+	 * contents of <i>level.dat</i>
+	 */
+	public PatchFunction<CompoundTag, Boolean> getLevelDatPatcher() { return null; }
+	
 	/**
 	 * Generates ready to use data for all currently registered patches. The list of
 	 * patches is selected by the current patch-level of the world.

src/main/java/ru/bclib/api/datafixer/PatchDidiFailException.java

@@ -0,0 +1,10 @@
+package ru.bclib.api.datafixer;
+
+public class PatchDidiFailException extends Exception {
+	public PatchDidiFailException(){
+		super();
+	}
+	public PatchDidiFailException(Exception e){
+		super(e);
+	}
+}

src/main/java/ru/bclib/api/datafixer/PatchFunction.java

@@ -0,0 +1,6 @@
+package ru.bclib.api.datafixer;
+
+@FunctionalInterface
+public interface PatchFunction<T, R> {
+	R apply(T t) throws PatchDidiFailException;
+}