| package org.apache.lucene.facet.taxonomy.writercache; |
| |
| import java.util.concurrent.locks.ReadWriteLock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock; |
| |
| import org.apache.lucene.facet.taxonomy.FacetLabel; |
| import org.apache.lucene.facet.taxonomy.writercache.TaxonomyWriterCache; |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| |
| /** |
| * {@link TaxonomyWriterCache} using {@link CompactLabelToOrdinal}. Although |
| * called cache, it maintains in memory all the mappings from category to |
| * ordinal, relying on that {@link CompactLabelToOrdinal} is an efficient |
| * mapping for this purpose. |
| * |
| * @lucene.experimental |
| */ |
| public class Cl2oTaxonomyWriterCache implements TaxonomyWriterCache { |
| |
| private final ReadWriteLock lock = new ReentrantReadWriteLock(); |
| private final int initialCapcity, numHashArrays; |
| private final float loadFactor; |
| |
| private volatile CompactLabelToOrdinal cache; |
| |
| /** Sole constructor. */ |
| public Cl2oTaxonomyWriterCache(int initialCapcity, float loadFactor, int numHashArrays) { |
| this.cache = new CompactLabelToOrdinal(initialCapcity, loadFactor, numHashArrays); |
| this.initialCapcity = initialCapcity; |
| this.numHashArrays = numHashArrays; |
| this.loadFactor = loadFactor; |
| } |
| |
| @Override |
| public void clear() { |
| lock.writeLock().lock(); |
| try { |
| cache = new CompactLabelToOrdinal(initialCapcity, loadFactor, numHashArrays); |
| } finally { |
| lock.writeLock().unlock(); |
| } |
| } |
| |
| @Override |
| public synchronized void close() { |
| cache = null; |
| } |
| |
| @Override |
| public boolean isFull() { |
| // This cache is never full |
| return false; |
| } |
| |
| @Override |
| public int get(FacetLabel categoryPath) { |
| lock.readLock().lock(); |
| try { |
| return cache.getOrdinal(categoryPath); |
| } finally { |
| lock.readLock().unlock(); |
| } |
| } |
| |
| @Override |
| public boolean put(FacetLabel categoryPath, int ordinal) { |
| lock.writeLock().lock(); |
| try { |
| cache.addLabel(categoryPath, ordinal); |
| // Tell the caller we didn't clear part of the cache, so it doesn't |
| // have to flush its on-disk index now |
| return false; |
| } finally { |
| lock.writeLock().unlock(); |
| } |
| } |
| |
| /** Returns the number of bytes in memory used by this object. */ |
| public int getMemoryUsage() { |
| return cache == null ? 0 : cache.getMemoryUsage(); |
| } |
| |
| } |