com.ait.toolkit.node.dev.debug.ObjectCache.java Source code

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Here is the source code for com.ait.toolkit.node.dev.debug.ObjectCache.java

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/*
 Copyright (c) 2014 Ahom Innovation Technologies. All rights reserved.
    
 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 com.ait.toolkit.node.dev.debug;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import com.google.gwt.core.client.JavaScriptObject;

/**
 * Simple cache for Java and JS objects by IDs
 *
 * 
 */
class ObjectCache {

    private final Map<Integer, JavaScriptObject> javaObjectsById = new HashMap<Integer, JavaScriptObject>();
    private final Map<JavaScriptObject, Integer> javaIdsByObject = new HashMap<JavaScriptObject, Integer>();
    private final Set<Integer> javaObjectsToFree = new HashSet<Integer>();
    private final Map<Integer, JavaScriptObject> jsObjectsById = new HashMap<Integer, JavaScriptObject>();
    private final Map<JavaScriptObject, Integer> jsIdsByObject = new HashMap<JavaScriptObject, Integer>();
    private int jsObjectCounter = 0;

    public ObjectCache() {
    }

    public void freeJavaObject(int id) {
        JavaScriptObject object = javaObjectsById.remove(id);
        if (object != null) {
            javaIdsByObject.remove(object);
        }
        javaObjectsToFree.add(id);
    }

    public Set<Integer> getJavaObjectsToFree() {
        return javaObjectsToFree;
    }

    public void clearJavaObjectsToFree() {
        javaObjectsToFree.clear();
    }

    public Integer getJavaObjectId(JavaScriptObject javaObjectReference) {
        return javaIdsByObject.get(javaObjectReference);
    }

    public JavaScriptObject getJavaObjectReference(int id, boolean create) {
        JavaScriptObject ref = javaObjectsById.get(id);
        if (ref == null) {
            if (!create) {
                throw new DebugRuntimeException("Unable to find Java object by ID: " + id);
            }
            ref = JavaScriptObject.createObject();
            javaObjectsById.put(id, ref);
            javaIdsByObject.put(ref, id);
        }
        return ref;
    }

    public void freeJavaScriptObject(int id) {
        JavaScriptObject object = jsObjectsById.remove(id);
        if (object != null) {
            jsIdsByObject.remove(object);
        }
    }

    public int getJavaScriptObjectId(JavaScriptObject jsObject, boolean create) {
        Integer id = jsIdsByObject.get(jsObject);
        if (id == null) {
            if (!create) {
                throw new DebugRuntimeException("Unable to find ID for JS object: " + jsObject);
            }
            do {
                id = ++jsObjectCounter;
                if (jsObjectCounter == Integer.MAX_VALUE) {
                    jsObjectCounter = 0;
                }
            } while (!jsObjectsById.containsKey(id));
            jsObjectsById.put(id, jsObject);
            jsIdsByObject.put(jsObject, id);
        }
        return id;
    }

    public JavaScriptObject getJavaScriptObject(int id) {
        return jsObjectsById.get(id);
    }
}