com.google.gwt.emul.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;
import jsinterop.annotations.JsType;
/** Contains logics for calculating hash codes in JavaScript. */
@JsType
public class HashCodes {
public static int getIdentityHashCode(Object o) {
switch (JsUtils.typeOf(o)) {
case "string":
return JsUtils.uncheckedCast(o).hashCode();
case "number":
return JsUtils.uncheckedCast(o).hashCode();
case "boolean":
return JsUtils.uncheckedCast(o).hashCode();
default:
return o == null ? 0 : getObjectIdentityHashCode(o);
}
}
private static int nextHash;
public static native int getObjectIdentityHashCode(Object o) /*-{
return o.$H || (o.$H = @HashCodes::getNextHash()());
}-*/;
public static int getNextHash() {
return ++nextHash;
}
}