| /* |
| * 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: |
| * <ul> |
| * <li>{@link com.google.gwt.user.client.rpc.impl.SerializerBase}</li> |
| * </ul> |
| */ |
| private static int getNextHashId() { |
| return ++sNextHashId; |
| } |
| } |