org.lunifera.runtime.common.state.impl.DataState.java Source code

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Here is the source code for org.lunifera.runtime.common.state.impl.DataState.java

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/**
 * Copyright (c) 2012 Committers of lunifera.org.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *    Florian Pirchner - initial API and implementation
 */
package org.lunifera.runtime.common.state.impl;

import java.util.Collection;

import org.lunifera.runtime.common.dispose.AbstractDisposable;
import org.lunifera.runtime.common.state.IDataState;

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;

/**
 * Responsible to cache data by a cache implementation.
 */
public class DataState extends AbstractDisposable implements IDataState {

    protected Cache<Object, Object> cache;
    protected final SharedStateContext sharedStateContext;

    public DataState(SharedStateContext sharedStateContext) {
        this.sharedStateContext = sharedStateContext;
    }

    @Override
    public boolean contains(Object key) {
        checkDisposed();

        if (cache == null) {
            return false;
        }
        return cache.getIfPresent(key) != null;
    }

    @Override
    public Object get(Object key) {
        checkDisposed();

        if (cache == null) {
            return null;
        }

        return cache.getIfPresent(key);
    }

    @Override
    public void register(Object key, Object object) {
        checkDisposed();

        if (contains(key)) {
            // already contained
            return;
        }

        ensureCache();
        cache.put(key, object);
    }

    protected void ensureCache() {
        if (cache == null) {
            cache = CacheBuilder.newBuilder().initialCapacity(250).weakValues().build();
        }
    }

    @Override
    public void registerAll(Collection<Object> objects, Hashing hasher) {
        checkDisposed();
        for (Object object : objects) {
            register(hasher.getHashCode(object), object);
        }
    }

    @Override
    public void invalidate(Object key) {
        checkDisposed();
        cache.invalidate(key);
    }

    @Override
    protected void internalDispose() {
        if (cache != null) {
            cache.invalidateAll();
            cache = null;
        }
    }

    @Override
    public long size() {
        if (cache == null) {
            return 0;
        }
        cache.cleanUp();
        return cache.size();
    }

    @Override
    public boolean empty() {
        return size() <= 0;
    }
}