Java tutorial
package proj.zoie.impl.indexing.internal; /** * 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. */ import it.unimi.dsi.fastutil.longs.LongSet; import java.io.File; import java.io.IOException; import java.util.concurrent.TimeoutException; import org.apache.log4j.Logger; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.index.IndexReader; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.IndexWriterConfig; import org.apache.lucene.index.IndexWriterConfig.OpenMode; import org.apache.lucene.index.SerialMergeScheduler; import org.apache.lucene.search.Similarity; import org.apache.lucene.store.Directory; import org.apache.lucene.store.RAMDirectory; import org.apache.lucene.util.Version; import proj.zoie.api.DocIDMapper; import proj.zoie.api.ZoieIndexReader; import proj.zoie.api.ZoieMultiReader; import proj.zoie.api.impl.ZoieMergePolicy; import proj.zoie.api.impl.ZoieMergePolicy.MergePolicyParams; import proj.zoie.api.impl.util.FileUtil; import proj.zoie.api.impl.util.IndexUtil; import proj.zoie.api.indexing.IndexReaderDecorator; public class RAMSearchIndex<R extends IndexReader> extends BaseSearchIndex<R> { private volatile String _version; private final RAMDirectory _directory; private final File _backingdir; private final IndexReaderDecorator<R> _decorator; private static ThreadLocal<IndexWriterConfig> indexWriterConfigStorage = new ThreadLocal<IndexWriterConfig>(); // a consistent pair of reader and deleted set private volatile ZoieIndexReader<R> _currentReader; private final MergePolicyParams _mergePolicyParams; public static final Logger log = Logger.getLogger(RAMSearchIndex.class); public RAMSearchIndex(String version, IndexReaderDecorator<R> decorator, SearchIndexManager<R> idxMgr, RAMDirectory ramIdxDir, File backingdir) { super(idxMgr, true); _directory = ramIdxDir; _backingdir = backingdir; _version = version; _decorator = decorator; _currentReader = null; _mergeScheduler = new SerialMergeScheduler(); _mergePolicyParams = new MergePolicyParams(); _mergePolicyParams.setNumLargeSegments(3); _mergePolicyParams.setMergeFactor(3); _mergePolicyParams.setMaxSmallSegments(4); } public void close() { super.close(); if (_currentReader != null) { _currentReader.decZoieRef(); } if (_directory != null) { _directory.close(); if (_backingdir != null) FileUtil.rmDir(_backingdir); } } public String getVersion() { return _version; } public void setVersion(String version) throws IOException { _version = version; synchronized (readerOpenLock) { readerOpenLock.notifyAll(); } } public int getNumdocs() { ZoieIndexReader<R> reader = null; try { synchronized (this) { reader = openIndexReader(); if (reader == null) return 0; reader.incZoieRef(); } return reader.numDocs(); } catch (IOException e) { log.error(e.getMessage(), e); } finally { if (reader != null) reader.decZoieRef(); } return 0; } public long sizeInBytes() { return _directory == null ? -1 : _directory.sizeInBytes(); } @Override public ZoieIndexReader<R> openIndexReader() throws IOException { return _currentReader; } @Override protected IndexReader openIndexReaderForDelete() throws IOException { if (IndexReader.indexExists(_directory)) { return IndexReader.open(_directory, false); } else { return null; } } private ZoieIndexReader<R> openIndexReaderInternal() throws IOException { if (IndexReader.indexExists(_directory)) { IndexReader srcReader = null; ZoieIndexReader<R> finalReader = null; try { // for RAM indexes, just get a new index reader srcReader = IndexReader.open(_directory, true); finalReader = ZoieIndexReader.open(srcReader, _decorator); DocIDMapper<?> mapper = _idxMgr._docIDMapperFactory .getDocIDMapper((ZoieMultiReader<R>) finalReader); finalReader.setDocIDMapper(mapper); return finalReader; } catch (IOException ioe) { // if reader decoration fails, still need to close the source reader if (srcReader != null) { srcReader.close(); } throw ioe; } } else { return null; // null indicates no index exist, following the contract } } public IndexWriter openIndexWriter(Analyzer analyzer, Similarity similarity) throws IOException { if (_indexWriter != null) return _indexWriter; ZoieMergePolicy mergePolicy = new ZoieMergePolicy(); mergePolicy.setMergePolicyParams(_mergePolicyParams); mergePolicy.setUseCompoundFile(false); IndexWriterConfig config = indexWriterConfigStorage.get(); if (config == null) { config = new IndexWriterConfig(Version.LUCENE_34, analyzer); indexWriterConfigStorage.set(config); } config.setOpenMode(OpenMode.CREATE_OR_APPEND); config.setMergeScheduler(_mergeScheduler); config.setMergePolicy(mergePolicy); config.setReaderPooling(false); if (similarity != null) { config.setSimilarity(similarity); } config.setRAMBufferSizeMB(3); IndexWriter idxWriter = new IndexWriter(_directory, config); _indexWriter = idxWriter; return idxWriter; } private final Object readerOpenLock = new Object(); public ZoieIndexReader<R> openIndexReader(String minVersion, long timeout) throws IOException, TimeoutException { if (timeout < 0) timeout = Long.MAX_VALUE; if (_versionComparator.compare(minVersion, _version) <= 0) { return _currentReader; } long startTimer = System.currentTimeMillis(); while (_versionComparator.compare(minVersion, _version) > 0) { synchronized (readerOpenLock) { try { readerOpenLock.wait(100); } catch (InterruptedException e) { // ignore } } long now = System.currentTimeMillis(); if (now - startTimer >= timeout) throw new TimeoutException("timed-out, took: " + (now - startTimer) + " ms"); } return _currentReader; } @Override public void refresh(boolean forceRefresh) throws IOException { synchronized (this) { ZoieIndexReader<R> reader = null; if (_currentReader == null) { reader = openIndexReaderInternal(); } else { reader = (ZoieIndexReader<R>) _currentReader.reopen(true); if (reader != _currentReader) { DocIDMapper<?> mapper = _idxMgr._docIDMapperFactory.getDocIDMapper((ZoieMultiReader<R>) reader); reader.setDocIDMapper(mapper); } } if (_currentReader != reader) { ZoieIndexReader<R> oldReader = _currentReader; _currentReader = reader; if (oldReader != null) ((ZoieIndexReader<?>) oldReader).decZoieRef();// .decRef(); } LongSet delDocs = _delDocs; clearDeletes(); markDeletes(delDocs); // re-mark deletes commitDeletes(); } } public int getSegmentCount() throws IOException { return _directory == null ? -1 : IndexUtil.getNumSegments(_directory); } }