javaemul.internal.HashCodes Maven / Gradle / Ivy
/*
* Copyright 2015 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 javaemul.internal;
/**
* Contains logics for calculating hash codes in JavaScript.
*/
public class HashCodes {
private static int sNextHashId = 0;
private static final String HASH_CODE_PROPERTY = "$H";
public static int hashCodeForString(String s) {
return StringHashCache.getHashCode(s);
}
public static int getIdentityHashCode(Object o) {
if (o == null) {
return 0;
}
return o instanceof String
? hashCodeForString(JsUtils.unsafeCastToString(o)) : getObjectIdentityHashCode(o);
}
public static native int getObjectIdentityHashCode(Object o) /*-{
return o.$H || (o.$H = @HashCodes::getNextHashId()());
}-*/;
/**
* Called from JSNI. Do not change this implementation without updating:
*
* - {@link com.google.gwt.user.client.rpc.impl.SerializerBase}
*
*/
private static int getNextHashId() {
return ++sNextHashId;
}
}