com.google.gwt.emul.java.util.IdentityHashMap Maven / Gradle / Ivy
/*
* Copyright 2011 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package java.util;
import com.google.gwt.core.client.impl.Impl;
import java.io.Serializable;
/**
* Map using reference equality on keys. [Sun
* docs]
*
* @param key type
* @param value type
*/
public class IdentityHashMap extends AbstractHashMap implements
Map, Cloneable, Serializable {
/**
* Ensures that RPC will consider type parameter K to be exposed. It will be
* pruned by dead code elimination.
*/
@SuppressWarnings("unused")
private K exposeKey;
/**
* Ensures that RPC will consider type parameter V to be exposed. It will be
* pruned by dead code elimination.
*/
@SuppressWarnings("unused")
private V exposeValue;
public IdentityHashMap() {
}
public IdentityHashMap(int ignored) {
super(ignored);
}
public IdentityHashMap(Map toBeCopied) {
super(toBeCopied);
}
public Object clone() {
return new IdentityHashMap(this);
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof Map)) {
return false;
}
Map otherMap = (Map) obj;
if (size() != otherMap.size()) {
return false;
}
for (Entry entry : otherMap.entrySet()) {
Object otherKey = entry.getKey();
Object otherValue = entry.getValue();
if (!containsKey(otherKey)) {
return false;
}
if (otherValue != get(otherKey)) {
return false;
}
}
return true;
}
@Override
public int hashCode() {
int hashCode = 0;
for (Entry entry : entrySet()) {
hashCode += System.identityHashCode(entry.getKey());
hashCode += System.identityHashCode(entry.getValue());
}
return hashCode;
}
@Override
boolean equals(Object value1, Object value2) {
return value1 == value2;
}
@Override
int getHashCode(Object key) {
return Impl.getHashCode(key);
}
}