/*
* 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.
*
* $Id: NameIndexer.java 571949 2007-09-02 10:52:38Z vgritsenko $
*/
package org.apache.xindice.core.indexer;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.xindice.core.Collection;
import org.apache.xindice.core.DBException;
import org.apache.xindice.core.data.Key;
import org.apache.xindice.core.data.Value;
import org.apache.xindice.core.filer.BTree;
import org.apache.xindice.core.filer.BTreeCallback;
import org.apache.xindice.core.filer.BTreeCorruptException;
import org.apache.xindice.util.Configuration;
import org.apache.xindice.xml.SymbolTable;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
/**
* NameIndexer is a basic implementation of the Indexer interface.
* It is used for maintaining element and element@attribute unique
* indexes.
*
* @version $Revision: 571949 $, $Date: 2007-09-02 06:52:38 -0400 (Sun, 02 Sep 2007) $
*/
public final class NameIndexer extends BTree implements Indexer {
private static final Log log = LogFactory.getLog(NameIndexer.class);
private static final IndexMatch[] EmptyMatches = new IndexMatch[0];
private static final String NAME = "name";
private static final String PATTERN = "pattern";
private Collection collection;
private SymbolTable symbols;
private String name;
private IndexPattern pattern;
private boolean wildcard;
private IndexerEventHandler handler;
public NameIndexer() {
}
public void setCollection(Collection collection) {
this.collection = collection;
this.symbols = collection.getSymbols();
}
private void setLocation(String location) {
setFile(new File(collection.getCollectionRoot(), location + ".idx"));
}
public void setConfig(Configuration config) {
super.setConfig(config);
try {
name = config.getAttribute(NAME);
String pattern = config.getAttribute(PATTERN);
wildcard = pattern.indexOf('*') != -1;
this.pattern = new IndexPattern(symbols, pattern, null);
setLocation(name);
setupHandler();
} catch (Exception e) {
if (log.isWarnEnabled()) {
log.warn("ignored exception", e);
}
}
}
private void setupHandler() {
handler = new BasicIndexerEventHandler() {
public void onNameAdded(IndexPattern pattern, Key key, short elemID, short attrID) throws DBException {
try {
addValue(getCombinedValue(key, elemID, attrID), 0);
} catch (IOException e) {
throw new BTreeCorruptException("Corruption detected on add", e);
}
}
public void onNameDeleted(IndexPattern pattern, Key key, short elemID, short attrID) throws DBException {
try {
removeValue(getCombinedValue(key, elemID, attrID));
} catch (IOException e) {
throw new BTreeCorruptException("Corruption detected on remove", e);
}
}
};
}
public String getName() {
return name;
}
public String getIndexStyle() {
return STYLE_NODENAME;
}
public IndexPattern[] getPatterns() {
return new IndexPattern[] { pattern };
}
private Value getCombinedValue(Key key, short elemID, short attrID) {
int l = key.getLength();
byte[] b = new byte[l + 5];
// Write the key
key.copyTo(b, 0, l);
b[l] = 0;
// Write the elemID
b[l + 1] = (byte) ((elemID >>> 8) & 0xFF);
b[l + 2] = (byte) ( elemID & 0xFF);
// Write the attrID
b[l + 3] = (byte) ((attrID >>> 8) & 0xFF);
b[l + 4] = (byte) ( attrID & 0xFF);
return new Value(b);
}
private IndexMatch getIndexMatch(Value v) {
int l = v.getLength() - 5;
Key key = v.keyAt(0, l);
short elemID = v.shortAt(l + 1);
short attrID = v.shortAt(l + 3);
return new IndexMatch(key, elemID, attrID);
}
public IndexMatch[] queryMatches(final IndexQuery query) throws DBException {
final List results = new ArrayList();
final IndexPattern pattern = query.getPattern();
try {
query(query, new BTreeCallback() {
public boolean indexInfo(Value value, long pos) {
IndexMatch match = getIndexMatch(value);
if (wildcard) {
IndexPattern pt = new IndexPattern(symbols, match.getElement(), match.getAttribute());
if (pt.getMatchLevel(pattern) > 0) {
results.add(match);
}
} else {
results.add(match);
}
return true;
}
});
} catch (DBException e) {
throw e;
} catch (Exception e) {
if (log.isWarnEnabled()) {
log.warn("ignored exception", e);
}
}
return (IndexMatch[]) results.toArray(EmptyMatches);
}
public IndexerEventHandler getIndexerEventHandler() {
return handler;
}
}