Added a shallow clone method.

Removed the identity cloner, as it's no longer needed.

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

@@ -30,6 +30,8 @@ import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.ConcurrentMap;
 
+import javax.annotation.Nullable;
+
 import org.bukkit.World;
 import org.bukkit.WorldType;
 import org.bukkit.entity.Entity;
@@ -38,13 +40,19 @@ import org.bukkit.inventory.ItemStack;
 import com.comphenix.protocol.injector.StructureCache;
 import com.comphenix.protocol.reflect.EquivalentConverter;
 import com.comphenix.protocol.reflect.FuzzyReflection;
+import com.comphenix.protocol.reflect.ObjectWriter;
 import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.reflect.cloning.AggregateCloner;
+import com.comphenix.protocol.reflect.cloning.Cloner;
+import com.comphenix.protocol.reflect.cloning.FieldCloner;
+import com.comphenix.protocol.reflect.cloning.AggregateCloner.BuilderParameters;
+import com.comphenix.protocol.reflect.instances.DefaultInstances;
 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.base.Function;
 import com.google.common.collect.Maps;
 
 /**
@@ -69,6 +77,21 @@ public class PacketContainer implements Serializable {
 	private static ConcurrentMap<Class<?>, Method> writeMethods = Maps.newConcurrentMap();
 	private static ConcurrentMap<Class<?>, Method> readMethods = Maps.newConcurrentMap();
 	
+	// Used to clone packets
+	private static final AggregateCloner DEEP_CLONER = AggregateCloner.DEFAULT;
+	private static final AggregateCloner SHALLOW_CLONER = AggregateCloner.newBuilder().
+			instanceProvider(DefaultInstances.DEFAULT).
+			andThen(new Function<BuilderParameters, Cloner>() {
+						@Override
+						public Cloner apply(@Nullable BuilderParameters param) {
+							return new FieldCloner(param.getAggregateCloner(), param.getInstanceProvider()) {{
+								// Use a default writer with no concept of cloning
+								writer = new ObjectWriter();
+							}};
+						}
+					}).
+			build();
+	
 	/**
 	 * Creates a packet container for a new packet.
 	 * @param id - ID of the packet to create.
@@ -364,12 +387,29 @@ public class PacketContainer implements Serializable {
 		return id;
 	}
 	
+	/**
+	 * Create a shallow copy of the current packet.
+	 * <p>
+	 * This merely writes the content of each field to the new class directly,
+	 * without performing any expensive copies. 
+	 * 
+	 * @return A shallow copy of the current packet.
+	 */
+	public PacketContainer shallowClone() {
+		Object clonedPacket = SHALLOW_CLONER.clone(getHandle());
+		return new PacketContainer(getID(), clonedPacket);
+	}
+	
 	/**
 	 * Create a deep copy of the current packet.
+	 * <p>
+	 * This will perform a full copy of the entire object tree, only skipping
+	 * known immutable objects and primitive types.
+	 * 
 	 * @return A deep copy of the current packet.
 	 */
 	public PacketContainer deepClone() {
-		Object clonedPacket = AggregateCloner.DEFAULT.clone(getHandle());
+		Object clonedPacket = DEEP_CLONER.clone(getHandle());
 		return new PacketContainer(getID(), clonedPacket);
 	}
 	

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

@@ -47,6 +47,11 @@ public class AggregateCloner implements Cloner {
 		}
 	}
 	
+	/**
+	 * Represents a builder for aggregate (combined) cloners.
+	 * 
+	 * @author Kristian
+	 */
 	public static class Builder {
 		private List<Function<BuilderParameters, Cloner>> factories = Lists.newArrayList();
 		private BuilderParameters parameters;
@@ -75,7 +80,7 @@ public class AggregateCloner implements Cloner {
 		 */
 		public Builder andThen(final Class<? extends Cloner> type) {
 			// Use reflection to generate a factory on the fly
-			return orCloner(new Function<BuilderParameters, Cloner>() {
+			return andThen(new Function<BuilderParameters, Cloner>() {
 				@Override
 				public Cloner apply(@Nullable BuilderParameters param) {
 					Object result = param.typeConstructor.create(type);
@@ -97,7 +102,7 @@ public class AggregateCloner implements Cloner {
 		 * @param factory - factory constructing the next cloner.
 		 * @return This builder.
 		 */
-		public Builder orCloner(Function<BuilderParameters, Cloner> factory) {
+		public Builder andThen(Function<BuilderParameters, Cloner> factory) {
 			factories.add(factory);
 			return this;
 		}

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

@@ -10,11 +10,11 @@ import com.comphenix.protocol.reflect.instances.InstanceProvider;
  * @author Kristian
  */
 public class FieldCloner implements Cloner {
-	private final Cloner defaultCloner;
-	private final InstanceProvider instanceProvider;
+	protected Cloner defaultCloner;
+	protected InstanceProvider instanceProvider;
 	
 	// Used to clone objects
-	private final ObjectWriter writer;
+	protected ObjectWriter writer;
 	
 	/**
 	 * Constructs a field cloner that copies objects by reading and writing the internal fields directly.

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

@@ -1,18 +0,0 @@
-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;
-	}
-}