/*
* eXist Open Source Native XML Database
* Copyright (C) 2005-2009 The eXist Project
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
*/
package org.exist.xquery.functions;
import org.apache.log4j.Logger;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Vector;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
import org.exist.EXistException;
import org.exist.dom.ExtArrayNodeSet;
import org.exist.dom.Match;
import org.exist.dom.NodeProxy;
import org.exist.dom.NodeSet;
import org.exist.numbering.NodeId;
import org.exist.storage.NativeTextEngine;
import org.exist.storage.TextSearchEngine;
import org.exist.storage.analysis.TextToken;
import org.exist.storage.analysis.Tokenizer;
import org.exist.util.GlobToRegex;
import org.exist.xquery.Constants;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.util.ExpressionDumper;
import org.exist.xquery.value.Sequence;
/**
* phrase() function : search an exact phrase in a NodeSet
*
*@author Bruno Chatel <bcha@chadocs.com> (March 30, 2005)
*/
public class ExtPhrase extends ExtFulltext {
private static final Logger logger = Logger.getLogger(ExtPhrase.class);
/**
*
* @param context
*/
public ExtPhrase(XQueryContext context) {
super(context, Constants.FULLTEXT_AND);
}
/**
*
* @param searchArg
* @param nodes
*/
public Sequence evalQuery(String searchArg, NodeSet nodes) throws XPathException {
String[] terms;
try {
terms = getSearchTerms(searchArg);
} catch (EXistException e) {
logger.error(e.getMessage());
throw new XPathException(this, e.getMessage(), e);
}
NodeSet hits = processQuery(terms, nodes);
if (hits == null)
return Sequence.EMPTY_SEQUENCE;
// Can return NPE ; prevents issue exact matches
TextSearchEngine engine = context.getBroker().getTextEngine();
if(engine==null){
throw new XPathException("The legacy fulltext indexing has been disabled by "
+ "default from version 1.4.1. Please consider migrating to "
+ "the new full text indexing..");
}
boolean hasWildcards = false;
for(int i = 0; i < terms.length; i++) {
hasWildcards |= NativeTextEngine.containsWildcards(terms[i]);
}
return hasWildcards ? patternMatch(context, terms, hits) : exactMatch(context, terms, hits);
}
/**
*
* @param context
* @param result
*/
private Sequence exactMatch(XQueryContext context, String[] terms, NodeSet result) {
TextToken token;
NodeSet r = new ExtArrayNodeSet();
final Tokenizer tok = context.getBroker().getTextEngine().getTokenizer();
// define search phrase for matches
String matchTerm = "";
for (int k = 0; k < terms.length ; k++) {
matchTerm = matchTerm + terms[k];
if (k != terms.length - 1)
matchTerm = matchTerm + "\\W*";
}
// iterate on results
for (Iterator i = result.iterator(); i.hasNext();) {
Vector matchGid = new Vector();
NodeProxy current = (NodeProxy) i.next();
// get first match
Match nextMatch = current.getMatches();
// remove previously found matches on current
current.setMatches(null);
// iterate on attach matches, with unicity of related nodeproxy gid
String term;
while(nextMatch != null) {
NodeId nodeId= nextMatch.getNodeId();
// if current gid has not been previously processed
if(!matchGid.contains(nodeId)) {
NodeProxy mcurrent = new NodeProxy(current.getDocument(), nodeId);
Match match = null;
int firstOffset = -1;
// add it in gid array
matchGid.add(nodeId);
String value = mcurrent.getNodeValue();
tok.setText(value);
int j = 0;
if (j < terms.length)
term = terms[j];
else
break;
int frequency = 0;
while ((token = tok.nextToken()) != null) {
String word = token.getText().toLowerCase();
if (word.equalsIgnoreCase(term)) {
j++;
if (j == terms.length) {
// all terms found
if (match == null)
match = nextMatch.createInstance(getExpressionId(), nodeId, matchTerm);
if (firstOffset < 0)
firstOffset = token.startOffset();
match.addOffset(firstOffset, token.endOffset() - firstOffset);
frequency++;
// start again on fist term
j = 0;
term = terms[j];
continue;
} else {
term = terms[j];
if (firstOffset < 0)
firstOffset = token.startOffset();
}
} else if (j > 0 && word.equalsIgnoreCase(terms[0])) {
// first search term found: start again
j = 1;
term = terms[j];
firstOffset = token.startOffset();
continue;
} else {
// reset
j = 0;
firstOffset = -1;
term = terms[j];
}
}
// if phrase found
if(frequency != 0) {
// add new match to current
current.addMatch(match);
// add current to result
r.add(current);
// reset frequency
frequency=0;
}
}
// process next match
nextMatch = nextMatch.getNextMatch();
}
}
// LOG.debug("found " + r.getLength());
return r;
}
/**
*
* @param context
* @param result
* @return
*/
private Sequence patternMatch(XQueryContext context, String[] terms, NodeSet result) {
// generate list of search term patterns
Pattern patterns[] = new Pattern[terms.length];
Matcher matchers[] = new Matcher[terms.length];
for (int i = 0; i < patterns.length; i++) {
try {
patterns[i] = Pattern.compile(GlobToRegex.globToRegexp(terms[i]),
Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE);
matchers[i] = patterns[i].matcher("");
} catch (PatternSyntaxException e) {
logger.error("malformed pattern" + e.getMessage());
return Sequence.EMPTY_SEQUENCE;
}
}
// walk through hits
ExtArrayNodeSet r = new ExtArrayNodeSet();
final Tokenizer tok = context.getBroker().getTextEngine().getTokenizer();
Matcher matcher;
for (Iterator i = result.iterator(); i.hasNext();) {
Match nextMatch;
Vector matchGid = new Vector();
NodeProxy current = (NodeProxy) i.next();
// get first match
nextMatch = current.getMatches();
// remove previously found matches on current
current.setMatches(null);
// iterate on attach matches, with unicity of related nodeproxy gid
while(nextMatch != null) {
Hashtable matchTable = new Hashtable();
NodeId nodeId = nextMatch.getNodeId();
// if current gid has not been previously processed
if(!matchGid.contains(nodeId)) {
NodeProxy mcurrent = new NodeProxy(current.getDocument(), nodeId);
// add it in gid array
matchGid.add(nodeId);
String value = mcurrent.getNodeValue();
tok.setText(value);
int j = 0;
if (j < patterns.length) {
//Pattern term = patterns[j];
matcher = matchers[j];
} else
break;
String matchTerm = null;
TextToken token;
while ((token = tok.nextToken()) != null) {
String word = token.getText().toLowerCase();
matcher.reset(word);
matchers[0].reset(word);
if (matcher.matches()) {
j++;
if(matchTerm == null)
matchTerm=word;
else
matchTerm = matchTerm + "\\W*" + word;
if (j == patterns.length) {
// all terms found
if(matchTable.containsKey(matchTerm)) {
// previously found matchTerm
Match match = (Match)(matchTable.get(matchTerm));
match.addOffset(token.startOffset(), matchTerm.length());
} else {
Match match = nextMatch.createInstance(getExpressionId(), nodeId, matchTerm);
match.addOffset(token.startOffset(), matchTerm.length());
matchTable.put(matchTerm,match);
}
// start again on fist term
j=0;
//Pattern term = patterns[j];
matcher = matchers[j];
matchTerm = null;
continue;
} else {
//Pattern term = patterns[j];
matcher = matchers[j];
}
} else if (j > 0 && matchers[0].matches()) {
// first search term found: start again
j=1;
//Pattern term = patterns[j];
matcher = matchers[j];
matchTerm = word;
continue;
} else {
// reset
j = 0;
//Pattern term = patterns[j];
matcher = matchers[j];
matchTerm = null;
continue;
}
}
// one or more match found
if(matchTable.size()!=0) {
Enumeration eMatch = matchTable.elements();
while(eMatch.hasMoreElements()){
Match match = (Match)(eMatch.nextElement());
current.addMatch(match);
}
// add current to result
r.add(current);
}
}
// process next match
nextMatch = nextMatch.getNextMatch();
}
}
return r;
}
/* (non-Javadoc)
* @see org.exist.xquery.functions.ExtFulltext#dump(org.exist.xquery.util.ExpressionDumper)
*/
public void dump(ExpressionDumper dumper) {
dumper.display("phrase(");
path.dump(dumper);
dumper.display(", ");
searchTerm.dump(dumper);
dumper.display(")");
}
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append("phrase(");
buf.append(path);
buf.append(", ");
buf.append(searchTerm);
buf.append(")");
return buf.toString();
}
}