1 /*******************************************************************************
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2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
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3 * in Industry THTH ry.
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4 * All rights reserved. This program and the accompanying materials
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5 * are made available under the terms of the Eclipse Public License v1.0
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6 * which accompanies this distribution, and is available at
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7 * http://www.eclipse.org/legal/epl-v10.html
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10 * VTT Technical Research Centre of Finland - initial API and implementation
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11 *******************************************************************************/
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12 package org.simantics.utils.datastructures.cache;
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16 * Caches the value provided by the back-end provider.
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18 * Cached version is equal to original in hashCode/equals wise.
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20 * @author Toni Kalajainen
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22 public class CachedProvider<V> implements IProvider<V> {
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24 public static final <V> IProvider<V> cache(IProvider<V> provider)
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26 if (provider instanceof CachedProvider<?>)
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28 return new CachedProvider<V>(provider);
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31 IProvider<V> backendProvider;
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34 CachedProvider(IProvider<V> orig)
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36 this.backendProvider = orig;
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40 public synchronized V get() throws ProvisionException {
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42 value = backendProvider.get();
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48 public int hashCode() {
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49 return backendProvider.hashCode();
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53 public boolean equals(Object obj) {
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54 return backendProvider.equals(obj);
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