dkpro.similarity.algorithms.vsm.store.vectorindex.VectorIndexWriter.java Source code

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Here is the source code for dkpro.similarity.algorithms.vsm.store.vectorindex.VectorIndexWriter.java

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/*******************************************************************************
 * Copyright 2012
 * Ubiquitous Knowledge Processing (UKP) Lab
 * Technische Universitt Darmstadt
 *
 * 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 dkpro.similarity.algorithms.vsm.store.vectorindex;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Properties;

import no.uib.cipr.matrix.Vector;

import org.apache.commons.io.IOUtils;

import com.sleepycat.bind.tuple.TupleBinding;

/**
 * Writes an ESA vector index.
 *
 * @author Richard Eckart de Castilho
 */
public class VectorIndexWriter implements VectorIndexContract {
    private File path;
    private BerkeleyDbEnvironment dbEnv;
    private BerkeleyDbDatabase db;
    private long dbCacheSize = DEFAULT_DB_CACHE;
    private int nConcepts;

    public VectorIndexWriter(File aPath, int aNConcepts) {
        path = aPath;
        nConcepts = aNConcepts;
    }

    public void setDbCacheSize(long aDbCacheSize) {
        dbCacheSize = aDbCacheSize;
    }

    public void put(String aTerm, Vector aVector) throws IOException {
        if (aVector == null || aTerm == null || aTerm.length() == 0) {
            return;
        }
        // It is important to cast the term to Object here, otherwise the wrong method is called
        getDb().put(aTerm, aVector);
    }

    public int getConceptCount() {
        return nConcepts;
    }

    public void close() {
        if (db != null) {
            db.close();
        }

        if (dbEnv != null) {
            dbEnv.close();
        }
    }

    private BerkeleyDbDatabase getDb() throws IOException {
        if (db == null) {
            dbEnv = new BerkeleyDbEnvironment(path.getAbsolutePath(), false, true, dbCacheSize);

            // init conceptVectorIndex
            TupleBinding<?> binding = new VectorBinding(nConcepts);
            db = new BerkeleyDbDatabase(dbEnv, CONCEPT_VECTOR_DB_NAME, false, true, binding);

            Writer out = null;
            try {
                Properties props = new Properties();
                props.setProperty(CONFIG_PROP_N_CONCEPTS, String.valueOf(nConcepts));
                out = new OutputStreamWriter(new FileOutputStream(new File(path, CONFIG_FILE_NAME)),
                        CONFIG_FILE_ENCODING);
                props.store(out, null);
            } finally {
                IOUtils.closeQuietly(out);
            }
        }
        return db;
    }
}