com.nearinfinity.blur.utils.PrimeDocCache.java Source code

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Here is the source code for com.nearinfinity.blur.utils.PrimeDocCache.java

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/*
 * Copyright (C) 2011 Near Infinity Corporation
 *
 * 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.nearinfinity.blur.utils;

import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexReader.ReaderClosedListener;
import org.apache.lucene.index.TermDocs;
import org.apache.lucene.util.OpenBitSet;

import com.nearinfinity.blur.log.Log;
import com.nearinfinity.blur.log.LogFactory;

public class PrimeDocCache {

    private static final Log LOG = LogFactory.getLog(PrimeDocCache.class);

    public static final OpenBitSet EMPTY_BIT_SET = new OpenBitSet();

    private static Map<Object, OpenBitSet> primeDocMap = new ConcurrentHashMap<Object, OpenBitSet>();

    /**
     * The way this method is called via warm up methods the likelihood of
     * creating multiple bitsets during a race condition is very low, that's why
     * this method is not synced.
     */
    public static OpenBitSet getPrimeDocBitSet(IndexReader reader) throws IOException {
        Object key = reader.getCoreCacheKey();
        OpenBitSet bitSet = primeDocMap.get(key);
        if (bitSet == null) {
            reader.addReaderClosedListener(new ReaderClosedListener() {
                @Override
                public void onClose(IndexReader reader) {
                    Object key = reader.getCoreCacheKey();
                    LOG.debug("Current size [" + primeDocMap.size() + "] Prime Doc BitSet removing for segment ["
                            + reader + "]");
                    primeDocMap.remove(key);
                }
            });
            LOG.debug("Prime Doc BitSet missing for segment [" + reader + "] current size [" + primeDocMap.size()
                    + "]");
            bitSet = new OpenBitSet(reader.maxDoc());
            primeDocMap.put(key, bitSet);
            TermDocs termDocs = reader.termDocs(BlurConstants.PRIME_DOC_TERM);
            while (termDocs.next()) {
                bitSet.set(termDocs.doc());
            }
            termDocs.close();
        }
        return bitSet;
    }

}