/*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* The Original Code is the Kowari Metadata Store.
*
* The Initial Developer of the Original Code is Plugged In Software Pty
* Ltd (http://www.pisoftware.com, mailto:info@pisoftware.com). Portions
* created by Plugged In Software Pty Ltd are Copyright (C) 2001,2002
* Plugged In Software Pty Ltd. All Rights Reserved.
*
* Contributor(s): N/A.
*
* [NOTE: The text of this Exhibit A may differ slightly from the text
* of the notices in the Source Code files of the Original Code. You
* should use the text of this Exhibit A rather than the text found in the
* Original Code Source Code for Your Modifications.]
*
*/
package org.mulgara.resolver.lucene;
// Java 2 standard packages
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;
// Third party packages
import org.apache.log4j.Logger;
// Locally written packages
import org.mulgara.query.rdf.Mulgara;
import org.mulgara.resolver.spi.InitializerException;
import org.mulgara.resolver.spi.NoSystemResolverFactoryException;
import org.mulgara.resolver.spi.Resolver;
import org.mulgara.resolver.spi.ResolverFactory;
import org.mulgara.resolver.spi.ResolverFactoryException;
import org.mulgara.resolver.spi.ResolverFactoryInitializer;
import org.mulgara.resolver.spi.ResolverSession;
/**
* Resolves constraints in models defined by static RDF documents.
*
* @created 2004-03-31
*
* @author <a href="http://staff.pisoftware.com/raboczi">Simon Raboczi</a>
*
* @version $Revision: 1.8 $
*
* @modified $Date: 2005/01/05 04:58:47 $ by $Author: newmana $
*
* @maintenanceAuthor $Author: newmana $
*
* @company <A href="mailto:info@PIsoftware.com">Plugged In Software</A>
*
* @copyright © 2003 <A href="http://www.PIsoftware.com/">Plugged In
* Software Pty Ltd</A>
*
* @licence <a href="{@docRoot}/../../LICENCE">Mozilla Public License v1.1</a>
*/
public class LuceneResolverFactory implements ResolverFactory {
/** Logger. */
private static final Logger logger = Logger.getLogger(LuceneResolverFactory.class);
public static final URI modelTypeURI = URI.create(Mulgara.NAMESPACE + "LuceneModel");
public static final URI searchURI = URI.create(Mulgara.NAMESPACE + "search");
public static final URI scoreURI = URI.create(Mulgara.NAMESPACE + "score");
private final Map<String,LuceneIndexerCache> indexerCaches = new HashMap<String,LuceneIndexerCache>();
private String directory;
//
// Constructors
//
/**
* Instantiate a {@link LuceneResolverFactory}.
*/
private LuceneResolverFactory(ResolverFactoryInitializer initializer) throws
InitializerException {
if (initializer == null) {
throw new IllegalArgumentException(
"Null initializer passed to LuceneResolverFactory");
}
try {
// Initialize fields
directory = initializer.getDirectory().toString();
// Claim mulgara:LuceneModel
initializer.addModelType(modelTypeURI, this);
} catch (NoSystemResolverFactoryException en) {
throw new InitializerException("Unable to obtain system resolver", en);
}
// Register LuceneConstraint
initializer.registerNewConstraint(new LuceneConstraintDescriptor());
// Register the LuceneConstraint's transformation
initializer.addSymbolicTransformation(new LuceneTransformer(modelTypeURI, searchURI, scoreURI));
}
//
// Methods implementing ResolverFactory
//
public void close() {
for (LuceneIndexerCache cache : indexerCaches.values()) {
cache.close();
}
indexerCaches.clear();
}
public void delete() {
for (LuceneIndexerCache cache : indexerCaches.values()) {
cache.close();
try {
cache.removeAllIndexes();
} catch (IOException ioe) {
logger.warn("Error deleting lucene index " + cache.getDirectory());
}
}
indexerCaches.clear();
}
/**
* {@inheritDoc}
* @return <code>null</code> - no default graphs for this resolver
*/
public Graph[] getDefaultGraphs() { return null; }
/**
* {@inheritDoc}
* @return <code>true</code> - this graph supports exports.
*/
public boolean supportsExport() {
return true;
}
/**
* Register this resolver upon database startup.
*
* @param resolverFactoryInitializer the database within which to find or
* create the various XML Schema resources
* @throws InitializerException if the XML Schema resources
* can't be found or created
*/
public static ResolverFactory newInstance(ResolverFactoryInitializer resolverFactoryInitializer)
throws InitializerException {
if (logger.isDebugEnabled()) logger.debug("Creating Lucene resolver factory");
return new LuceneResolverFactory(resolverFactoryInitializer);
}
/**
* Obtain a Lucene resolver.
*
* @param resolverSession the session which this query is local to
* @param canWrite {@inheritDoc}; ignored in this implementation
* @throws IllegalArgumentException if <var>resolverSession</var> is
* <code>null</code>
* @throws ResolverFactoryException {@inheritDoc}
*/
public Resolver newResolver(boolean canWrite, ResolverSession resolverSession, Resolver systemResolver)
throws ResolverFactoryException {
if (logger.isDebugEnabled()) logger.debug("Creating Lucene resolver");
return canWrite
? new LuceneResolver(modelTypeURI, resolverSession, this, true)
: new ReadOnlyLuceneResolver(modelTypeURI, resolverSession, this);
}
/**
* Get an indexer-cache for the given model.
*
* @param model the model to the indexer-cache for
* @return the indexer-cache
* @throws IOException if an error occurred creating an indexer-cache
*/
LuceneIndexerCache getIndexerCache(String model) throws IOException {
synchronized (indexerCaches) {
LuceneIndexerCache cache = indexerCaches.get(model);
if (cache == null) {
indexerCaches.put(model, cache = new LuceneIndexerCache(new File(directory, model).toString()));
}
return cache;
}
}
}