/*
* This file is part of Mixin, licensed under the MIT License (MIT).
*
* Copyright (c) SpongePowered <https://www.spongepowered.org>
* Copyright (c) contributors
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package org.spongepowered.asm.mixin.injection;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import org.spongepowered.asm.lib.tree.AbstractInsnNode;
import org.spongepowered.asm.mixin.injection.struct.Target;
import org.spongepowered.asm.util.Bytecode;
/**
* Used to keep track of instruction nodes in a {@link Target} method which are
* targetted by various types of injector. This collection is populated during
* the first injector pass and allows injectors to keep track of their targets
* even when the target method is being manipulated by other injectors.
*/
public class InjectionNodes extends ArrayList<InjectionNodes.InjectionNode> {
/**
* Never gonna give you up
*/
private static final long serialVersionUID = 1L;
/**
* A node targetted by one or more injectors. Using this wrapper allows
* injectors to be aware of when their target node is removed or replace by
* another injector. It also allows injectors to decorate certain nodes with
* custom metadata to allow arbitration between injectors to take place.
*/
public static class InjectionNode implements Comparable<InjectionNode> {
/**
* The original node targetted
*/
private final AbstractInsnNode originalTarget;
/**
* Initially set to the {@link #originalTarget}, if an injector removes
* or replaces this node then points to the current target. Can be null
* if the node is removed.
*/
private AbstractInsnNode currentTarget;
/**
* Injector decorations on this node
*/
private Map<String, Object> decorations;
/**
* Create a new node wrapper for the specified target node
*
* @param node target node
*/
public InjectionNode(AbstractInsnNode node) {
this.currentTarget = this.originalTarget = node;
}
/**
* Get the original target of this node
*/
public AbstractInsnNode getOriginalTarget() {
return this.originalTarget;
}
/**
* Get the current target of this node, can be null if the node was
* replaced
*/
public AbstractInsnNode getCurrentTarget() {
return this.currentTarget;
}
/**
* Replace this node with the specified target
*
* @param target new node
*/
public InjectionNode replace(AbstractInsnNode target) {
this.currentTarget = target;
return this;
}
/**
* Remove the node
*/
public InjectionNode remove() {
this.currentTarget = null;
return this;
}
/**
* Checks whether the original or current target of this node match the
* specified node
*
* @param node node to check
* @return true if the supplied node matches either of this node's
* internal identities
*/
public boolean matches(AbstractInsnNode node) {
return this.originalTarget == node || this.currentTarget == node;
}
/**
* Get whether this node has been replaced
*/
public boolean isReplaced() {
return this.originalTarget != this.currentTarget;
}
/**
* Get whether this node has been removed
*/
public boolean isRemoved() {
return this.currentTarget == null;
}
/**
* Decorate this node with arbitrary metadata for injector arbitration
*
* @param key meta key
* @param value meta value
* @param <V> value type
*/
public <V> InjectionNode decorate(String key, V value) {
if (this.decorations == null) {
this.decorations = new HashMap<String, Object>();
}
this.decorations.put(key, value);
return this;
}
/**
* Get whether this node is decorated with the specified key
*
* @param key meta key
* @return true if the specified decoration exists
*/
public boolean hasDecoration(String key) {
return this.decorations != null && this.decorations.get(key) != null;
}
/**
* Get the specified decoration
*
* @param key meta key
* @return decoration value or null if absent
* @param <V> value type
*/
@SuppressWarnings("unchecked")
public <V> V getDecoration(String key) {
return (V) (this.decorations == null ? null : this.decorations.get(key));
}
/* (non-Javadoc)
* @see java.lang.Comparable#compareTo(java.lang.Object)
*/
@Override
public int compareTo(InjectionNode other) {
return other == null ? Integer.MAX_VALUE : this.hashCode() - other.hashCode();
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return String.format("InjectionNode[%s]", Bytecode.describeNode(this.currentTarget).replaceAll("\\s+", " "));
}
}
/**
* Add a tracked node to this collection if it does not already exist
*
* @param node Instruction node to add
* @return wrapper for the specified node
*/
public InjectionNode add(AbstractInsnNode node) {
InjectionNode injectionNode = this.get(node);
if (injectionNode == null) {
injectionNode = new InjectionNode(node);
this.add(injectionNode);
}
return injectionNode;
}
/**
* Get a tracked node from this collection if it already exists, returns
* null if the node is not tracked
*
* @param node instruction node
* @return wrapper node or null if not tracked
*/
public InjectionNode get(AbstractInsnNode node) {
for (InjectionNode injectionNode : this) {
if (injectionNode.matches(node)) {
return injectionNode;
}
}
return null;
}
/**
* Get whether this collection contains a mapping for the specified insn
*
* @param node instruction node to check
* @return true if a wrapper exists for the node
*/
public boolean contains(AbstractInsnNode node) {
return this.get(node) != null;
}
/**
* Replace the specified node with the new node, does not update the wrapper
* if no wrapper exists for <tt>oldNode</tt>
*
* @param oldNode node being replaced
* @param newNode node to replace with
*/
public void replace(AbstractInsnNode oldNode, AbstractInsnNode newNode) {
InjectionNode injectionNode = this.get(oldNode);
if (injectionNode != null) {
injectionNode.replace(newNode);
}
}
/**
* Mark the specified node as removed, does not update the wrapper if no
* wrapper exists
*
* @param node node being removed
*/
public void remove(AbstractInsnNode node) {
InjectionNode injectionNode = this.get(node);
if (injectionNode != null) {
injectionNode.remove();
}
}
}