net.sourceforge.docfetcher.model.index.IndexWriterAdapter.java Source code

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Here is the source code for net.sourceforge.docfetcher.model.index.IndexWriterAdapter.java

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/*******************************************************************************
 * Copyright (c) 2010, 2011 Tran Nam Quang.
 * 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:
 *    Tran Nam Quang - initial API and implementation
 *******************************************************************************/

package net.sourceforge.docfetcher.model.index;

import java.io.Closeable;
import java.io.IOException;

import net.sourceforge.docfetcher.model.Fields;
import net.sourceforge.docfetcher.model.IndexRegistry;
import net.sourceforge.docfetcher.util.CheckedOutOfMemoryError;
import net.sourceforge.docfetcher.util.annotations.NotNull;
import net.sourceforge.docfetcher.util.annotations.VisibleForPackageGroup;

import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriter.MaxFieldLength;
import org.apache.lucene.index.Term;
import org.apache.lucene.store.Directory;

import com.google.common.io.Closeables;

/**
 * Wrapper for Lucene's IndexWriter that adds some functionality.
 * 
 * @author Tran Nam Quang
 */
@VisibleForPackageGroup
public final class IndexWriterAdapter implements Closeable {

    public static final Term idTerm = new Term(Fields.UID.key());

    @NotNull
    private IndexWriter writer;

    public IndexWriterAdapter(@NotNull Directory luceneDir) throws IOException {
        writer = new IndexWriter(luceneDir, IndexRegistry.analyzer, MaxFieldLength.UNLIMITED);
    }

    // may throw OutOfMemoryError
    public void add(@NotNull Document document) throws IOException, CheckedOutOfMemoryError {
        try {
            writer.addDocument(document);
        } catch (OutOfMemoryError e) {
            reopenWriterAndThrow(e);
        }
    }

    // may throw OutOfMemoryError
    public void update(@NotNull String uid, @NotNull Document document)
            throws IOException, CheckedOutOfMemoryError {
        try {
            writer.updateDocument(idTerm.createTerm(uid), document);
        } catch (OutOfMemoryError e) {
            reopenWriterAndThrow(e);
        }
    }

    private void reopenWriterAndThrow(@NotNull OutOfMemoryError e) throws IOException, CheckedOutOfMemoryError {
        /*
         * According to the IndexWriter javadoc, we're supposed to immediately
         * close the IndexWriter if IndexWriter.addDocument(...) or
         * IndexWriter.updateDocument(...) hit OutOfMemoryErrors.
         */
        Directory indexDir = writer.getDirectory();
        Closeables.closeQuietly(writer);
        writer = new IndexWriter(indexDir, IndexRegistry.analyzer, MaxFieldLength.UNLIMITED);
        throw new CheckedOutOfMemoryError(e);
    }

    public void delete(@NotNull String uid) throws IOException {
        writer.deleteDocuments(idTerm.createTerm(uid));
    }

    public void close() throws IOException {
        writer.close();
    }

}