Added a generic cloning library to properly support deepClone().

ProtocolLib/src/main/java/com/comphenix/protocol/events/PacketContainer.java

@@ -17,8 +17,6 @@
 
 package com.comphenix.protocol.events;
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
@@ -41,6 +39,7 @@ import com.comphenix.protocol.injector.StructureCache;
 import com.comphenix.protocol.reflect.EquivalentConverter;
 import com.comphenix.protocol.reflect.FuzzyReflection;
 import com.comphenix.protocol.reflect.StructureModifier;
+import com.comphenix.protocol.reflect.cloning.AggregateCloner;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.wrappers.BukkitConverters;
 import com.comphenix.protocol.wrappers.ChunkPosition;
@@ -370,35 +369,8 @@ public class PacketContainer implements Serializable {
 	 * @return A deep copy of the current packet.
 	 */
 	public PacketContainer deepClone() {
-		ObjectOutputStream output = null;
-		ObjectInputStream input = null;
-		
-		try {
-			// Use a small buffer of 32 bytes initially.
-			ByteArrayOutputStream bufferOut = new ByteArrayOutputStream(); 
-			output = new ObjectOutputStream(bufferOut);
-			output.writeObject(this);
-			
-			ByteArrayInputStream bufferIn = new ByteArrayInputStream(bufferOut.toByteArray());
-			input = new ObjectInputStream(bufferIn);
-			return (PacketContainer) input.readObject();
-			
-		} catch (IOException e) {
-			throw new IllegalStateException("Unexpected error occured during object cloning.", e);
-		} catch (ClassNotFoundException e) {
-			// Cannot happen
-			throw new IllegalStateException("Unexpected failure with serialization.", e);
-		} finally {
-			try {
-				if (output != null)
-					output.close();
-				if (input != null)
-					input.close();
-				
-			} catch (IOException e) {
-				// STOP IT
-			}
-		}
+		Object clonedPacket = AggregateCloner.DEFAULT.clone(getHandle());
+		return new PacketContainer(getID(), clonedPacket);
 	}
 	
 	private void writeObject(ObjectOutputStream output) throws IOException {

ProtocolLib/src/main/java/com/comphenix/protocol/injector/MinecraftRegistry.java

@@ -182,6 +182,22 @@ class MinecraftRegistry {
 		throw new IllegalArgumentException("The packet ID " + packetID + " is not registered.");
 	}
 	
+	/**
+	 * Retrieve the packet ID of a given packet.
+	 * @param packet - the type of packet to check.
+	 * @return The ID of the given packet.
+	 * @throws IllegalArgumentException If this is not a valid packet.
+	 */
+	public static int getPacketID(Class<?> packet) {
+		if (packet == null)
+			throw new IllegalArgumentException("Packet type class cannot be NULL.");
+		if (!MinecraftReflection.getPacketClass().isAssignableFrom(packet))
+			throw new IllegalArgumentException("Type must be a packet.");
+		
+		// The registry contains both the overridden and original packets
+		return getPacketToID().get(packet);
+	}
+	
 	/**
 	 * Find the first superclass that is not a CBLib proxy object.
 	 * @param clazz - the class whose hierachy we're going to search through.

ProtocolLib/src/main/java/com/comphenix/protocol/injector/StructureCache.java

@@ -64,6 +64,27 @@ public class StructureCache {
 		return getStructure(id, true);
 	}
 	
+	/**
+	 * Retrieve a cached structure modifier given a packet type.
+	 * @param packetType - packet type.
+	 * @return A structure modifier.
+	 */
+	public static StructureModifier<Object> getStructure(Class<?> packetType) {
+		// Compile structures by default
+		return getStructure(packetType, true);
+	}
+	
+	/**
+	 * Retrieve a cached structure modifier given a packet type.
+	 * @param packetType - packet type.
+	 * @param compile - whether or not to asynchronously compile the structure modifier.
+	 * @return A structure modifier.
+	 */
+	public static StructureModifier<Object> getStructure(Class<?> packetType, boolean compile) {
+		// Get the ID from the class
+		return getStructure(MinecraftRegistry.getPacketID(packetType), compile);
+	}
+	
 	/**
 	 * Retrieve a cached structure modifier for the given packet id.
 	 * @param id - packet ID.

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/ObjectWriter.java

@@ -17,21 +17,63 @@
 
 package com.comphenix.protocol.reflect;
 
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
+import com.comphenix.protocol.injector.StructureCache;
+import com.comphenix.protocol.reflect.cloning.Cloner;
+import com.comphenix.protocol.reflect.cloning.IdentityCloner;
+import com.comphenix.protocol.utility.MinecraftReflection;
+
 /**
  * Can copy an object field by field.
  * 
  * @author Kristian
  */
 public class ObjectWriter {
-
 	// Cache structure modifiers
 	@SuppressWarnings("rawtypes")
 	private static ConcurrentMap<Class, StructureModifier<Object>> cache =
 			new ConcurrentHashMap<Class, StructureModifier<Object>>();
 	
+	/**
+	 * The default value cloner to use.
+	 */
+	private static final Cloner DEFAULT_CLONER = new IdentityCloner();
+	
+	/**
+	 * Retrieve a usable structure modifier for the given object type.
+	 * <p>
+	 * Will attempt to reuse any other structure modifiers we have cached.
+	 * @param type - the type of the object we are modifying.
+	 * @return A structure modifier for the given type.
+	 */
+	private static StructureModifier<Object> getModifier(Class<?> type) {
+		Class<?> packetClass = MinecraftReflection.getPacketClass();
+		
+		// Handle subclasses of the packet class with our custom structure cache
+		if (!type.equals(packetClass) && packetClass.isAssignableFrom(type)) {
+			// Delegate to our already existing registry of structure modifiers
+			return StructureCache.getStructure(type);
+		}
+		
+		StructureModifier<Object> modifier = cache.get(type);
+		
+		// Create the structure modifier if we haven't already
+		if (modifier == null) {
+			StructureModifier<Object> value = new StructureModifier<Object>(type, null, false);
+			modifier = cache.putIfAbsent(type, value);
+			
+			if (modifier == null)
+				modifier = value;
+		}
+		
+		// And we're done
+		return modifier;
+	}
+	
 	/**
 	 * Copy every field in object A to object B. Each value is copied directly, and is not cloned.
 	 * <p>
@@ -41,22 +83,31 @@ public class ObjectWriter {
 	 * @param commonType - type containing each field to copy.
 	 */
 	public static void copyTo(Object source, Object destination, Class<?> commonType) {
-		
+		// Note that we indicate that public fields will be copied the first time around
+		copyToInternal(source, destination, commonType, DEFAULT_CLONER, true);
+	}
+
+	/**
+	 * Copy every field in object A to object B. Each value is copied using the supplied cloner.
+	 * <p>
+	 * The two objects must have the same number of fields of the same type.
+	 * @param source - fields to copy.
+	 * @param destination - fields to copy to.
+	 * @param commonType - type containing each field to copy.
+	 * @param valueCloner - a object responsible for copying the content of each field.
+	 */
+	public static void copyTo(Object source, Object destination, Class<?> commonType, Cloner valueCloner) {
+		copyToInternal(source, destination, commonType, valueCloner, true);
+	}
+	
+	// Internal method that will actually implement the recursion
+	private static void copyToInternal(Object source, Object destination, Class<?> commonType, Cloner valueCloner, boolean copyPublic) {
 		if (source == null)
 			throw new IllegalArgumentException("Source cannot be NULL");
 		if (destination == null)
 			throw new IllegalArgumentException("Destination cannot be NULL");
 		
-		StructureModifier<Object> modifier = cache.get(commonType);
-
-		// Create the structure modifier if we haven't already
-		if (modifier == null) {
-			StructureModifier<Object> value = new StructureModifier<Object>(commonType, null, false);
-			modifier = cache.putIfAbsent(commonType, value);
-			
-			if (modifier == null)
-				modifier = value;
-		}
+		StructureModifier<Object> modifier = getModifier(commonType);
 		
 		// Add target
 		StructureModifier<Object> modifierSource = modifier.withTarget(source);
@@ -65,20 +116,21 @@ public class ObjectWriter {
 		// Copy every field
 		try {
 			for (int i = 0; i < modifierSource.size(); i++) {
-				if (!modifierDest.isReadOnly(i)) {
-					Object value = modifierSource.read(i);
-					modifierDest.write(i, value);
-				}
+				Field field = modifierSource.getField(i);
+				int mod = field.getModifiers();
 				
-				// System.out.println(String.format("Writing value %s to %s", 
-				//		value, modifier.getFields().get(i).getName()));
+				// Skip static fields. We also get the "public" field fairly often, so we'll skip that.
+				if (!Modifier.isStatic(mod) && (!Modifier.isPublic(mod) || copyPublic)) {
+					Object value = modifierSource.read(i);
+					modifierDest.write(i, valueCloner.clone(value));
+				}
 			}
 			
 			// Copy private fields underneath
 			Class<?> superclass = commonType.getSuperclass();
 			
 			if (!superclass.equals(Object.class)) {
-				copyTo(source, destination, superclass);
+				copyToInternal(source, destination, superclass, valueCloner, false);
 			}
 			
 		} catch (FieldAccessException e) {

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/StructureModifier.java

@@ -201,10 +201,16 @@ public class StructureModifier<TField> {
 	 * @return TRUE if the field by the given index is read-only, FALSE otherwise.
 	 */
 	public boolean isReadOnly(int fieldIndex) {
-		if (fieldIndex < 0 || fieldIndex >= data.size())
-			throw new IllegalArgumentException("Index parameter is not within [0 - " + data.size() + ")");
-		
-		return Modifier.isFinal(data.get(fieldIndex).getModifiers());
+		return Modifier.isFinal(getField(fieldIndex).getModifiers());
+	}
+	
+	/**
+	 * Determine if a given field is public or not.
+	 * @param fieldIndex - field index.
+	 * @return TRUE if the field is public, FALSE otherwise.
+	 */
+	public boolean isPublic(int fieldIndex) {
+		return Modifier.isPublic(getField(fieldIndex).getModifiers());
 	}
 	
 	/**
@@ -499,6 +505,19 @@ public class StructureModifier<TField> {
 		return ImmutableList.copyOf(data);
 	}
 
+	/**
+	 * Retrieve a field by index.
+	 * @param fieldIndex - index of the field to retrieve.
+	 * @return The field represented with the given index.
+	 * @throws IllegalArgumentException If no field with the given index can be found.
+	 */
+	public Field getField(int fieldIndex) {
+		if (fieldIndex < 0 || fieldIndex >= data.size())
+			throw new IllegalArgumentException("Index parameter is not within [0 - " + data.size() + ")");
+		
+		return data.get(fieldIndex);
+	}
+	
 	/**
 	 * Retrieve every value stored in the fields of the current type.
 	 * @return Every field value.
@@ -560,4 +579,6 @@ public class StructureModifier<TField> {
 		
 		return result;
 	}
+
+
 }

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/cloning/AggregateCloner.java

@@ -0,0 +1,236 @@
+package com.comphenix.protocol.reflect.cloning;
+
+import java.lang.ref.WeakReference;
+import java.util.Collections;
+import java.util.List;
+
+import javax.annotation.Nullable;
+
+import com.comphenix.protocol.reflect.instances.DefaultInstances;
+import com.comphenix.protocol.reflect.instances.ExistingGenerator;
+import com.comphenix.protocol.reflect.instances.InstanceProvider;
+import com.google.common.base.Function;
+import com.google.common.collect.Lists;
+
+/**
+ * Implements a cloning procedure by trying multiple methods in turn until one is successful.
+ * 
+ * @author Kristian
+ */
+public class AggregateCloner implements Cloner {
+	public static class BuilderParameters {
+		// Can only be modified by the builder
+		private InstanceProvider instanceProvider;
+		private Cloner aggregateCloner;
+
+		// Used to construct the different types
+		private InstanceProvider typeConstructor;
+		
+		private BuilderParameters() {
+			// Only allow inner classes to construct it.
+		}
+		
+		/**
+		 * Retrieve the instance provider last set in the builder.
+		 * @return Current instance provider.
+		 */
+		public InstanceProvider getInstanceProvider() {
+			return instanceProvider;
+		}
+
+		/**
+		 * Retrieve the aggregate cloner that is being built.
+		 * @return The parent cloner.
+		 */
+		public Cloner getAggregateCloner() {
+			return aggregateCloner;
+		}
+	}
+	
+	public static class Builder {
+		private List<Function<BuilderParameters, Cloner>> factories = Lists.newArrayList();
+		private BuilderParameters parameters;
+		
+		/**
+		 * Create a new aggregate builder.
+		 */
+		public Builder() {
+			this.parameters = new BuilderParameters();
+		}
+		
+		/**
+		 * Set the instance provider supplied to all cloners in this builder.
+		 * @param provider - new instance provider.
+		 * @return The current builder.
+		 */
+		public Builder instanceProvider(InstanceProvider provider) {
+			this.parameters.instanceProvider = provider;
+			return this;
+		}
+
+		/**
+		 * Add the next cloner that will be considered in turn.
+		 * @param type - the type of the next cloner.
+		 * @return This builder.
+		 */
+		public Builder andThen(final Class<? extends Cloner> type) {
+			// Use reflection to generate a factory on the fly
+			return orCloner(new Function<BuilderParameters, Cloner>() {
+				@Override
+				public Cloner apply(@Nullable BuilderParameters param) {
+					Object result = param.typeConstructor.create(type);
+					
+					if (result == null) {
+						throw new IllegalStateException("Constructed NULL instead of " + type);
+					}
+						
+					if (type.isAssignableFrom(result.getClass())) 
+						return (Cloner) result;
+					else 
+						throw new IllegalStateException("Constructed " + result.getClass() + " instead of " + type);
+				}
+			});
+		}
+		
+		/**
+		 * Add the next cloner that will be considered in turn.
+		 * @param factory - factory constructing the next cloner.
+		 * @return This builder.
+		 */
+		public Builder orCloner(Function<BuilderParameters, Cloner> factory) {
+			factories.add(factory);
+			return this;
+		}
+		
+		/**
+		 * Build a new aggregate cloner using the supplied values.
+		 * @return A new aggregate cloner.
+		 */
+		public AggregateCloner build() {
+			AggregateCloner newCloner = new AggregateCloner();
+			
+			// The parameters we will pass to our cloners
+			Cloner paramCloner = new NullableCloner(newCloner);
+			InstanceProvider paramProvider = parameters.instanceProvider;
+			
+			// Initialize parameters
+			parameters.aggregateCloner = paramCloner;
+			parameters.typeConstructor = DefaultInstances.fromArray(
+					ExistingGenerator.fromObjectArray(new Object[] { paramCloner, paramProvider })
+			);
+			
+			// Build every cloner in the correct order
+			List<Cloner> cloners = Lists.newArrayList();
+			
+			for (int i = 0; i < factories.size(); i++) {
+				Cloner cloner = factories.get(i).apply(parameters);
+				
+				// See if we were successful
+				if (cloner != null)
+					cloners.add(cloner);
+				else
+					throw new IllegalArgumentException(
+							String.format("Cannot create cloner from %s (%s)", factories.get(i), i)
+					);
+			}
+			
+			// We're done
+			newCloner.setCloners(cloners);
+			return newCloner;
+		}
+	}
+	
+	/**
+	 * Represents a default aggregate cloner.
+	 */
+	public static final AggregateCloner DEFAULT = newBuilder().
+			instanceProvider(DefaultInstances.DEFAULT).
+			andThen(BukkitCloner.class).
+			andThen(ImmutableDetector.class).
+			andThen(CollectionCloner.class).
+			andThen(FieldCloner.class).
+			build();
+	
+	// List of clone methods
+	private List<Cloner> cloners;
+
+	private WeakReference<Object> lastObject;
+	private int lastResult;
+	
+	/**
+	 * Begins constructing a new aggregate cloner.
+	 * @return A builder for a new aggregate cloner.
+	 */
+	public static Builder newBuilder() {
+		return new Builder();
+	}
+	
+	/**
+	 * Construct a new, empty aggregate cloner.
+	 */
+	private AggregateCloner() {
+		// Only used by our builder above.
+	}
+	
+	/**
+	 * Retrieves a view of the current list of cloners.
+	 * @return Current cloners.
+	 */
+	public List<Cloner> getCloners() {
+		return Collections.unmodifiableList(cloners);
+	}
+	
+	/**
+	 * Set the cloners that will be used.
+	 * @param cloners - the cloners that will be used.
+	 */
+	private void setCloners(Iterable<? extends Cloner> cloners) {
+		this.cloners = Lists.newArrayList(cloners);
+	}
+
+	@Override
+	public boolean canClone(Object source) {
+		// Optimize a bit
+		lastResult = getFirstCloner(source);
+		lastObject = new WeakReference<Object>(source);
+		return lastResult >= 0 && lastResult < cloners.size();
+	}
+	
+	/**
+	 * Retrieve the index of the first cloner capable of cloning the given object.
+	 * <p>
+	 * Returns an invalid index if no cloner is able to clone the object.
+	 * @param source - the object to clone.
+	 * @return The index of the cloner object.
+	 */
+	private int getFirstCloner(Object source) {
+		for (int i = 0; i < cloners.size(); i++) {
+			if (cloners.get(i).canClone(source))
+				return i;
+		}
+		
+		return cloners.size();
+	}
+
+	@Override
+	public Object clone(Object source) {
+		if (source == null)
+			throw new IllegalAccessError("source cannot be NULL.");
+		int index = 0;
+		
+		// Are we dealing with the same object?
+		if (lastObject != null && lastObject.get() == source) {
+			index = lastResult;
+		} else {
+			index = getFirstCloner(source);
+		}
+
+		// Make sure the object is valid
+		if (index < cloners.size()) {
+			return cloners.get(index).clone(source);
+		}
+		
+		// Damn - failure
+		throw new IllegalArgumentException("Cannot clone " + source + ": No cloner is sutable.");
+	}
+}

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/cloning/BukkitCloner.java

@@ -0,0 +1,56 @@
+package com.comphenix.protocol.reflect.cloning;
+
+import com.comphenix.protocol.reflect.EquivalentConverter;
+import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.wrappers.BukkitConverters;
+import com.comphenix.protocol.wrappers.ChunkPosition;
+import com.comphenix.protocol.wrappers.WrappedDataWatcher;
+
+/**
+ * Represents an object that can clone a specific list of Bukkit- and Minecraft-related objects.
+ * 
+ * @author Kristian
+ */
+public class BukkitCloner implements Cloner {
+	// List of classes we support
+	private Class<?>[] clonableClasses = { MinecraftReflection.getItemStackClass(), MinecraftReflection.getChunkPositionClass(), 
+										   MinecraftReflection.getDataWatcherClass() };
+	
+	private int findMatchingClass(Class<?> type) {
+		// See if is a subclass of any of our supported superclasses
+		for (int i = 0; i < clonableClasses.length; i++) {
+			if (clonableClasses[i].isAssignableFrom(type))
+				return i;
+		}
+		
+		return -1;
+	}
+	
+	@Override
+	public boolean canClone(Object source) {
+		if (source == null)
+			return false;
+		
+		return findMatchingClass(source.getClass()) >= 0;
+	}
+	
+	@Override
+	public Object clone(Object source) {
+		if (source == null)
+			throw new IllegalArgumentException("source cannot be NULL.");
+		
+		// Convert to a wrapper 
+		switch (findMatchingClass(source.getClass())) {
+			case 0:
+				return MinecraftReflection.getMinecraftItemStack(MinecraftReflection.getBukkitItemStack(source).clone());
+			case 1:
+				EquivalentConverter<ChunkPosition> chunkConverter = ChunkPosition.getConverter();
+				return chunkConverter.getGeneric(clonableClasses[1], chunkConverter.getSpecific(source));
+			case 2:
+				EquivalentConverter<WrappedDataWatcher> dataConverter = BukkitConverters.getDataWatcherConverter();
+				return dataConverter.getGeneric(clonableClasses[2], dataConverter.getSpecific(source).deepClone());
+			default:
+				throw new IllegalArgumentException("Cannot clone objects of type " + source.getClass());
+		}
+	}
+}

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/cloning/Cloner.java

@@ -0,0 +1,25 @@
+package com.comphenix.protocol.reflect.cloning;
+
+/**
+ * Represents an object that is capable of cloning other objects.
+ * 
+ * @author Kristian
+ */
+public interface Cloner {
+	/**
+	 * Determine whether or not the current cloner can clone the given object.
+	 * @param source - the object that is being considered.
+	 * @return TRUE if this cloner can actually clone the given object, FALSE otherwise.
+	 */
+	public boolean canClone(Object source);
+	
+	/**
+	 * Perform the clone. 
+	 * <p>
+	 * This method should never be called unless a corresponding {@link #canClone(Object)} returns TRUE.
+	 * @param source - the value to clone.
+	 * @return A cloned value.
+	 * @throws IllegalArgumentException If this cloner cannot perform the clone.
+	 */
+	public Object clone(Object source);
+}

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/cloning/CollectionCloner.java

@@ -0,0 +1,146 @@
+package com.comphenix.protocol.reflect.cloning;
+
+import java.lang.reflect.Array;
+import java.lang.reflect.Constructor;
+import java.util.Collection;
+
+/**
+ * Attempts to clone collection and array classes.
+ * 
+ * @author Kristian
+ */
+public class CollectionCloner implements Cloner {
+	private final Cloner defaultCloner;
+
+	/**
+	 * Constructs a new collection and array cloner with the given inner element cloner.
+	 * @param defaultCloner - default inner element cloner.
+	 */
+	public CollectionCloner(Cloner defaultCloner) {
+		this.defaultCloner = defaultCloner;
+	}
+
+	@Override
+	public boolean canClone(Object source) {
+		if (source == null)
+			return false;
+		
+		Class<?> clazz = source.getClass();
+		return Collection.class.isAssignableFrom(clazz) || clazz.isArray();
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public Object clone(Object source) {
+		if (source == null)
+			throw new IllegalArgumentException("source cannot be NULL.");
+		
+		Class<?> clazz = source.getClass();
+		
+		if (source instanceof Collection) {
+			Collection<Object> copy = null; 
+			
+			// Not all collections implement "clone", but most *do* implement the "copy constructor" pattern
+			try {
+				Constructor<?> constructCopy = clazz.getConstructor(Collection.class);
+				copy = (Collection<Object>) constructCopy.newInstance(source);
+			} catch (NoSuchMethodException e) {
+				copy = (Collection<Object>) cloneObject(clazz, source);
+			} catch (Exception e) {
+				throw new RuntimeException("Cannot construct collection.", e);
+			}
+			
+			// Next, clone each element in the collection
+			copy.clear();
+			
+			for (Object element : (Collection<Object>) source) {
+				if (defaultCloner.canClone(element))
+					copy.add(defaultCloner.clone(element));
+				else
+					throw new IllegalArgumentException("Cannot clone " + element + " in collection " + source);
+			}
+			
+			return copy;
+			
+			// Second possibility
+		} else if (clazz.isArray()) {
+			// Get the length
+			int lenght = Array.getLength(source);
+			Class<?> component = clazz.getComponentType();
+			
+			// Can we speed things up by making a shallow copy instead?
+			if (ImmutableDetector.isImmutable(component)) {
+				return clonePrimitive(component, source);
+			}
+			
+			// Create a new copy
+			Object copy = Array.newInstance(clazz.getComponentType(), lenght);
+			
+			// Set each element
+			for (int i = 0; i < lenght; i++) {
+				Object element = Array.get(source, i);
+				
+				if (defaultCloner.canClone(element))
+					Array.set(copy, i, defaultCloner.clone(element));
+				else
+					throw new IllegalArgumentException("Cannot clone " + element + " in array " + source);
+			}
+			
+			// And we're done
+			return copy;
+		}
+		
+		throw new IllegalArgumentException(source + " is not an array nor a Collection.");
+	}
+	
+	/**
+	 * Clone a primitive or immutable array by calling its clone method.
+	 * @param component - the component type of the array.
+	 * @param source - the array itself.
+	 * @return The cloned array.
+	 */
+	private Object clonePrimitive(Class<?> component, Object source) {
+		// Cast and call the correct version
+		if (byte.class.equals(component))
+			return ((byte[]) source).clone();
+		else if (short.class.equals(component))
+			return ((short[]) source).clone();
+		else if (int.class.equals(component))
+			return ((int[]) source).clone();
+		else if (long.class.equals(component))
+			return ((long[]) source).clone();
+		else if (float.class.equals(component))
+			return ((float[]) source).clone();
+		else if (double.class.equals(component))
+			return ((double[]) source).clone();
+		else if (char.class.equals(component))
+			return ((char[]) source).clone();
+		else if (boolean.class.equals(component))
+			return ((boolean[]) source).clone();
+		else
+			return ((Object[]) source).clone();
+	}
+	
+	/**
+	 * Clone an object by calling "clone" using reflection.
+	 * @param clazz - the class type.
+	 * @param obj - the object to clone.
+	 * @return The cloned object.
+	 */
+	private Object cloneObject(Class<?> clazz, Object source) {
+		// Try to clone it instead
+		try {
+			return clazz.getMethod("clone").invoke(source);
+		} catch (Exception e1) {
+			throw new RuntimeException("Cannot copy " + source + " (" + clazz + ")", e1);
+		}
+	}
+	
+	/**
+	 * Retrieve the default cloner used to clone the content of each element in the collection.
+	 * @return Cloner used to clone elements.
+	 */
+	public Cloner getDefaultCloner() {
+		return defaultCloner;
+	}
+}

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/cloning/FieldCloner.java

@@ -0,0 +1,61 @@
+package com.comphenix.protocol.reflect.cloning;
+
+import com.comphenix.protocol.reflect.ObjectWriter;
+import com.comphenix.protocol.reflect.instances.InstanceProvider;
+
+/**
+ * Represents a class capable of cloning objects by deeply copying its fields.
+ * 
+ * @author Kristian
+ */
+public class FieldCloner implements Cloner {
+	private final Cloner defaultCloner;
+	private final InstanceProvider instanceProvider;
+	
+	/**
+	 * Constructs a field cloner that copies objects by reading and writing the internal fields directly.
+	 * @param defaultCloner - the default cloner used while copying fields.
+	 * @param instanceProvider - used to construct new, empty copies of a given type.
+	 */
+	public FieldCloner(Cloner defaultCloner, InstanceProvider instanceProvider) {
+		this.defaultCloner = defaultCloner;
+		this.instanceProvider = instanceProvider;
+	}
+
+	@Override
+	public boolean canClone(Object source) {
+		if (source == null)
+			return false;
+		
+		// Attempt to create the type
+		return instanceProvider.create(source.getClass()) != null;
+	}
+
+	@Override
+	public Object clone(Object source) {
+		if (source == null)
+			throw new IllegalArgumentException("source cannot be NULL.");
+		
+		Object copy = instanceProvider.create(source.getClass());
+		
+		// Copy public and private fields alike. Skip static and transient fields.
+		ObjectWriter.copyTo(source, copy, source.getClass(), defaultCloner);
+		return copy;
+	}
+	
+	/**
+	 * Retrieve the default cloner used to clone the content of each field.
+	 * @return Cloner used to clone fields.
+	 */
+	public Cloner getDefaultCloner() {
+		return defaultCloner;
+	}
+
+	/**
+	 * Retrieve the instance provider this cloner is using to create new, empty classes.
+	 * @return The instance provider in use.
+	 */
+	public InstanceProvider getInstanceProvider() {
+		return instanceProvider;
+	}
+}

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/cloning/IdentityCloner.java

@@ -0,0 +1,18 @@
+package com.comphenix.protocol.reflect.cloning;
+
+/**
+ * Represents a cloner that simply returns the given object.
+ * 
+ * @author Kristian
+ */
+public class IdentityCloner implements Cloner {
+	@Override
+	public boolean canClone(Object source) {
+		return true;
+	}
+
+	@Override
+	public Object clone(Object source) {
+		return source;
+	}
+}

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/cloning/ImmutableDetector.java

@@ -0,0 +1,70 @@
+package com.comphenix.protocol.reflect.cloning;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetSocketAddress;
+import java.net.URI;
+import java.net.URL;
+import java.util.Locale;
+import java.util.UUID;
+
+import com.google.common.primitives.Primitives;
+
+/**
+ * Detects classes that are immutable, and thus doesn't require cloning.
+ * <p>
+ * This ought to have no false positives, but plenty of false negatives.
+ * 
+ * @author Kristian
+ */
+public class ImmutableDetector implements Cloner {
+	// Notable immutable classes we might encounter
+	private static final Class<?>[] immutableClasses = { 
+		StackTraceElement.class, BigDecimal.class, 
+		BigInteger.class, Locale.class, UUID.class, 
+		URL.class, URI.class, Inet4Address.class, 
+		Inet6Address.class, InetSocketAddress.class
+	};
+	
+	@Override
+	public boolean canClone(Object source) {
+		// Don't accept NULL
+		if (source == null)
+			return false;
+		
+		return isImmutable(source.getClass());
+	}
+	
+	/**
+	 * Determine if the given type is probably immutable.
+	 * @param type - the type to check.
+	 * @return TRUE if the type is immutable, FALSE otherwise.
+	 */
+	public static boolean isImmutable(Class<?> type) {
+		// Cases that are definitely not true
+		if (type.isArray())
+			return false;
+		
+		// All primitive types
+		if (Primitives.isWrapperType(type) || String.class.equals(type))
+			return true;
+		// May not be true, but if so, that kind of code is broken anyways
+		if (type.isEnum())
+			return true;
+			
+		for (Class<?> clazz : immutableClasses)
+			if (clazz.equals(type))
+				return true;
+		
+		// Probably not
+		return false;
+	}
+	
+	@Override
+	public Object clone(Object source) {
+		// Safe if the class is immutable
+		return source;
+	}
+}

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/cloning/NullableCloner.java

@@ -0,0 +1,32 @@
+package com.comphenix.protocol.reflect.cloning;
+
+/**
+ * Creates a cloner wrapper that accepts and clones NULL values.
+ * 
+ * @author Kristian
+ */
+public class NullableCloner implements Cloner {
+	protected Cloner wrapped;
+	
+	public NullableCloner(Cloner wrapped) {
+		this.wrapped = wrapped;
+	}
+
+	@Override
+	public boolean canClone(Object source) {
+		return true;
+	}
+
+	@Override
+	public Object clone(Object source) {
+		// Don't pass the NULL value to the cloner
+		if (source == null)
+			return null;
+		else
+			return wrapped.clone(source);
+	}
+
+	public Cloner getWrapped() {
+		return wrapped;
+	}
+}

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/instances/DefaultInstances.java

@@ -20,6 +20,8 @@ package com.comphenix.protocol.reflect.instances;
 import java.lang.reflect.Constructor;
 import java.util.*;
 
+import javax.annotation.Nullable;
+
 import net.sf.cglib.proxy.Enhancer;
 
 import com.google.common.base.Objects;
@@ -30,7 +32,7 @@ import com.google.common.collect.ImmutableList;
  * @author Kristian
  *
  */
-public class DefaultInstances {
+public class DefaultInstances implements InstanceProvider {
 
 	/**
 	 * Standard default instance provider.
@@ -326,4 +328,9 @@ public class DefaultInstances {
 		}
 		return false;
 	}
+
+	@Override
+	public Object create(@Nullable Class<?> type) {
+		return getDefault(type);
+	}
 }

ProtocolLib/src/main/java/com/comphenix/protocol/reflect/instances/ExistingGenerator.java

@@ -18,13 +18,16 @@
 package com.comphenix.protocol.reflect.instances;
 
 import java.lang.reflect.Field;
+import java.util.Collection;
 import java.util.HashMap;
+import java.util.LinkedList;
 import java.util.Map;
 
 import javax.annotation.Nullable;
 
 import com.comphenix.protocol.reflect.FieldUtils;
 import com.comphenix.protocol.reflect.FuzzyReflection;
+import com.google.common.collect.Lists;
 
 /**
  * Provides instance constructors using a list of existing values.
@@ -33,8 +36,52 @@ import com.comphenix.protocol.reflect.FuzzyReflection;
  * @author Kristian
  */
 public class ExistingGenerator implements InstanceProvider {
+	/**
+	 * Represents a single node in the tree of possible values.
+	 * 
+	 * @author Kristian
+	 */
+	private static final class Node {
+		private Map<Class<?>, Node> children;
+		private Class<?> key;
+		private Object value;
+		private int level;
+		
+		public Node(Class<?> key, Object value, int level) {
+			this.children = new HashMap<Class<?>, Node>();
+			this.key = key;
+			this.value = value;
+			this.level = level;
+		}
 
-	private Map<String, Object> existingValues = new HashMap<String, Object>();
+		public Node addChild(Node node) {
+			children.put(node.key, node);
+			return node;
+		}
+		
+		public int getLevel() {
+			return level;
+		}
+
+		public Collection<Node> getChildren() {
+			return children.values();
+		}
+		
+		public Object getValue() {
+			return value;
+		}
+
+		public void setValue(Object value) {
+			this.value = value;
+		}
+		
+		public Node getChild(Class<?> clazz) {
+			return children.get(clazz);
+		}
+	}
+	
+	// Represents the root node
+	private Node root = new Node(null, null, 0);
 	
 	private ExistingGenerator() {
 		// Only accessible to the constructors
@@ -110,18 +157,94 @@ public class ExistingGenerator implements InstanceProvider {
 		if (value == null)
 			throw new IllegalArgumentException("Value cannot be NULL.");
 		
-		existingValues.put(value.getClass().getName(), value);
-	}
-
-	private void addObject(Class<?> type, Object value) {
-		existingValues.put(type.getName(), value);
+		addObject(value.getClass(), value);
 	}
 	
+	private void addObject(Class<?> type, Object value) {
+		Node node = getLeafNode(root, type, false);
+		
+		// Set the value
+		node.setValue(value);
+	}
+	
+	private Node getLeafNode(final Node start, Class<?> type, boolean readOnly) {
+		Class<?>[] path = getHierachy(type);
+		Node current = start;
+		
+		for (int i = 0; i < path.length; i++) {
+			Node next = getNext(current, path[i], readOnly);
+			
+			// Try every interface too
+			if (next == null && readOnly) {
+				current = null;
+				break;
+			}
+
+			current = next;
+		}
+		
+		// And we're done
+		return current;
+	}
+
+	private Node getNext(Node current, Class<?> clazz, boolean readOnly) {
+		Node next = current.getChild(clazz);
+		
+		// Add a new node if needed
+		if (next == null && !readOnly) {
+			next = current.addChild(new Node(clazz, null, current.getLevel() + 1));
+		}
+		
+		// Add interfaces
+		if (next != null && !readOnly && !clazz.isInterface()) {
+			for (Class<?> clazzInterface : clazz.getInterfaces()) {
+				getLeafNode(root, clazzInterface, readOnly).addChild(next);
+			}
+		}
+		return next;
+	}
+	
+	private Node getLowestLeaf(Node current) {
+		Node candidate = current;
+		
+		// Depth-first search
+		for (Node child : current.getChildren()) {
+			Node subtree = getLowestLeaf(child);
+			
+			// Get the lowest node
+			if (subtree.getValue() != null && candidate.getLevel() < subtree.getLevel()) {
+				candidate = subtree;
+			}
+		}
+		
+		return candidate;
+	}
+	
+	private Class<?>[] getHierachy(Class<?> type) {
+		LinkedList<Class<?>> levels = Lists.newLinkedList();
+		
+		// Add each class from the hierachy
+		for (; type != null; type = type.getSuperclass()) {
+			levels.addFirst(type);
+		}
+		
+		return levels.toArray(new Class<?>[0]);
+	}
+
 	@Override
 	public Object create(@Nullable Class<?> type) {
-		Object value = existingValues.get(type.getName());
-
+		// Locate the type in the hierachy
+		Node node = getLeafNode(root, type, true);
+		
+		// Next, get the lowest leaf node
+		if (node != null) {
+			node = getLowestLeaf(node);
+		}
+			
 		// NULL values indicate that the generator failed
-		return value;
+		if (node != null)
+			return node.getValue();
+		else
+			return null;
 	}
 }

ProtocolLib/src/main/java/com/comphenix/protocol/utility/MinecraftReflection.java

@@ -112,6 +112,24 @@ public class MinecraftReflection {
 		return fullName.substring(0, fullName.lastIndexOf("."));
 	}
 	
+	/**
+	 * Dynamically retrieve the Bukkit entity from a given entity.
+	 * @param nmsObject - the NMS entity.
+	 * @return A bukkit entity.
+	 * @throws RuntimeException If we were unable to retrieve the Bukkit entity.
+	 */
+	public static Object getBukkitEntity(Object nmsObject) {
+		if (nmsObject == null)
+			return null;
+		
+		// We will have to do this dynamically, unfortunately
+		try {
+			return nmsObject.getClass().getMethod("getBukkitEntity").invoke(nmsObject);
+		} catch (Exception e) {
+			throw new RuntimeException("Cannot get Bukkit entity from " + nmsObject, e);
+		}
+	}
+	
 	/**
 	 * Determine if a given object can be found within the package net.minecraft.server.
 	 * @param obj - the object to test.
@@ -138,25 +156,7 @@ public class MinecraftReflection {
 		String javaName = obj.getClass().getName();
 		return javaName.startsWith(MINECRAFT_PREFIX_PACKAGE) && javaName.endsWith(className);
  	}
-		
-	/**
-	 * Dynamically retrieve the Bukkit entity from a given entity.
-	 * @param nmsObject - the NMS entity.
-	 * @return A bukkit entity.
-	 * @throws RuntimeException If we were unable to retrieve the Bukkit entity.
-	 */
-	public static Object getBukkitEntity(Object nmsObject) {
-		if (nmsObject == null)
-			return null;
-		
-		// We will have to do this dynamically, unfortunately
-		try {
-			return nmsObject.getClass().getMethod("getBukkitEntity").invoke(nmsObject);
-		} catch (Exception e) {
-			throw new RuntimeException("Cannot get Bukkit entity from " + nmsObject, e);
-		}
-	}
-	
+			
 	/**
 	 * Determine if a given object is a ChunkPosition.
 	 * @param obj - the object to test.

ProtocolLib/src/test/java/com/comphenix/protocol/events/PacketContainerTest.java

@@ -5,6 +5,7 @@ import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
+import java.lang.reflect.Array;
 import java.util.List;
 
 // Will have to be updated for every version though
@@ -23,12 +24,15 @@ import org.junit.runner.RunWith;
 import org.powermock.core.classloader.annotations.PrepareForTest;
 
 import com.comphenix.protocol.Packets;
+import com.comphenix.protocol.reflect.EquivalentConverter;
 import com.comphenix.protocol.reflect.FieldUtils;
 import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.wrappers.BukkitConverters;
 import com.comphenix.protocol.wrappers.ChunkPosition;
 import com.comphenix.protocol.wrappers.WrappedDataWatcher;
 import com.comphenix.protocol.wrappers.WrappedWatchableObject;
+
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 
@@ -36,6 +40,9 @@ import com.google.common.collect.Lists;
 @RunWith(org.powermock.modules.junit4.PowerMockRunner.class)
 @PrepareForTest(CraftItemFactory.class)
 public class PacketContainerTest {
+	// Helper converters
+	private EquivalentConverter<WrappedDataWatcher> watchConvert = BukkitConverters.getDataWatcherConverter();
+	private EquivalentConverter<ItemStack> itemConvert = BukkitConverters.getItemStackConverter();
 	
 	@BeforeClass
 	public static void initializeBukkit() throws IllegalAccessException {
@@ -203,23 +210,15 @@ public class PacketContainerTest {
 	}
 	
 	private boolean equivalentItem(ItemStack first, ItemStack second) {
-		if (first == null)
+		if (first == null) {
 			return second == null;
-		else if (second == null)
+		} else if (second == null) {
 			return false;
-		else
+		} else {
 			return first.getType().equals(second.getType());
+		}
 	}
 	
-	private boolean equivalentPacket(PacketContainer first, PacketContainer second) {
-		if (first == null)
-			return second == null;
-		else if (second == null)
-			return false;
-		else
-			return first.getModifier().getValues().equals(second.getModifier().getValues());
-	}
-
 	@Test
 	public void testGetWorldTypeModifier() {
 		PacketContainer loginPacket = new PacketContainer(Packets.Server.LOGIN);
@@ -324,7 +323,16 @@ public class PacketContainerTest {
 				PacketContainer cloned = constructed.deepClone();
 				
 				// Make sure they're equivalent
-				assertTrue("Packet " + id + " could not be cloned.", equivalentPacket(constructed, cloned));
+				StructureModifier<Object> firstMod = constructed.getModifier(), secondMod = cloned.getModifier();
+				assertEquals(firstMod.size(), secondMod.size());
+
+				// Make sure all the fields are equivalent
+				for (int i = 0; i < firstMod.size(); i++) {
+					if (firstMod.getField(i).getType().isArray())
+						assertArrayEquals(getArray(firstMod.read(i)), getArray(secondMod.read(i)));
+					else
+						testEquality(firstMod.read(i), secondMod.read(i));
+				}
 				
 			} catch (IllegalArgumentException e) {
 				if (!registered) {
@@ -337,4 +345,36 @@ public class PacketContainerTest {
 			}
 		}
 	}
+	
+	// Convert to objects that support equals()
+	private void testEquality(Object a, Object b) {
+		if (a != null && b != null) {
+			if (MinecraftReflection.isDataWatcher(a)) {
+				a = watchConvert.getSpecific(a);
+				b = watchConvert.getSpecific(b);
+			} else if (MinecraftReflection.isItemStack(a)) {
+				a = itemConvert.getSpecific(a);
+				b = itemConvert.getSpecific(b);
+			}
+		}
+		
+		assertEquals(a, b);
+	}
+	
+	/**
+	 * Get the underlying array as an object array.
+	 * @param val - array wrapped as an Object.
+	 * @return An object array.
+	 */
+	private Object[] getArray(Object val) {
+	    if (val instanceof Object[])
+	        return (Object[]) val;
+	    
+	     int arrlength = Array.getLength(val);
+	     Object[] outputArray = new Object[arrlength];
+	     
+	     for (int i = 0; i < arrlength; ++i)
+	        outputArray[i] = Array.get(val, i);
+	     return outputArray;
+	}
 }