/*************************************************************************
*
* $RCSfile: RoleFiller.java,v $
*
* $Revision: 1.1 $
*
* last change: $Author: abi $ $Date: 2000/11/30 18:03:09 $
*
* The Contents of this file are made available subject to the terms of
* either of the following licenses
*
* - GNU Lesser General Public License Version 2.1
* - Sun Industry Standards Source License Version 1.1
*
* Sun Microsystems Inc., October, 2000
*
* GNU Lesser General Public License Version 2.1
* =============================================
* Copyright 2000 by Sun Microsystems, Inc.
* 901 San Antonio Road, Palo Alto, CA 94303, USA
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software Foundation.
*
* This library 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 library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
*
* Sun Industry Standards Source License Version 1.1
* =================================================
* The contents of this file are subject to the Sun Industry Standards
* Source 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.openoffice.org/license.html.
*
* Software provided under this License is provided on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING,
* WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS,
* MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING.
* See the License for the specific provisions governing your rights and
* obligations concerning the Software.
*
* The Initial Developer of the Original Code is: Sun Microsystems, Inc.
*
* Copyright: 2000 by Sun Microsystems, Inc.
*
* All Rights Reserved.
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* Contributor(s): _______________________________________
*
*
************************************************************************/
package com.sun.xmlsearch.qe;
import java.io.PrintStream;
import com.sun.xmlsearch.util.Location;
class RoleFiller {
static int Threshold = 300;
private ConceptData _conceptData;
private byte _fixedRole;
private short _filled;
private int _begin;
private int _end;
private int _limit;
private RoleFiller _next;
private RoleFiller[] _fillers;
public static final RoleFiller STOP = new RoleFiller();
private RoleFiller() {}
public RoleFiller(int nColumns, ConceptData first, int role,
int pos, int limit) {
_conceptData = first;
_fixedRole = (byte)role; // primary/constitutive concept/role
_filled = (short)(1 << _fixedRole);
_begin = pos; // offset in file
_end = _begin + first.getConceptLength();
_limit = limit;
_next = null;
_fillers = new RoleFiller[nColumns];
_fillers[role] = this;
}
public void print(PrintStream out) {
out.println(_begin + ", " + _end);
}
void makeQueryHit(Query q, int nColumns, int doc, double penalty) {
if (q.goodEnough(penalty)) {
int[] array =
q.getConceptArrayOfNewHit(penalty,
new Location(doc, _begin, _end));
for (int i = 0; i < nColumns; i++)
array[i] = (_filled & 1 << i) != 0 ? _fillers[i].getConcept() : 0;
}
}
boolean isHit() {
return _filled > (1 << _fixedRole);
}
double getScore() {
return _conceptData.getScore();
}
int getConcept() {
return _conceptData.getConcept();
}
RoleFiller next() {
return _next;
}
void use(RoleFiller[] place, int index) {
if (place[index] != null) {
RoleFiller rf = place[index];
place[index] = this;
_next = rf;
while (rf._limit >= _begin) {
// check if we can grow/improve a hit
// we don't ever replace filler's fixed role
if (_fixedRole != rf._fixedRole) {
if ((rf._filled & (1 << _fixedRole)) == 0) { // not filled yet
rf._filled |= 1 << _fixedRole;
rf._fillers[_fixedRole] = this;
rf._end = _end;
}
else
rf.considerReplacementWith(this);
}
if (rf._next != null)
rf = rf._next;
else
return;
}
}
else
place[index] = this;
}
private void considerReplacementWith(RoleFiller replacement) {
// !!! simplistic for now
// needs gap and out of order
int role = replacement._fixedRole;
if (replacement.getScore() > _fillers[role].getScore())
_fillers[role] = replacement;
}
private double penalty(Query query, int nColumns) {
int length = _end - _begin + 1;
double penalty = query.lookupPenalty(_filled);
// !!! here is a chance to check against query if hit worth scoring further
// might not be if query already has lots of good hits
for (int i = 0; i < nColumns; i++)
if ((_filled & (1 << i)) != 0) {
penalty += _fillers[i]._conceptData.getPenalty();
length -= _fillers[i]._conceptData.getConceptLength() + 1;
if ((_filled >> (i + 1)) != 0)
for (int j = i + 1; j < nColumns; j++)
if ((_filled & 1 << j) != 0 && _fillers[j]._begin < _begin)
penalty += query.getOutOufOrderPenalty();
}
return penalty + length*query.getGapPenalty();
}
public void scoreList(Query query, int document) {
int nColumns = query.getNColumns();
RoleFiller candidateHit = this; // function called for the head of list
RoleFiller next; // lookahead: if overlap, if so, is it better
// 'candidateHit' always points at the current candidate to be converted to a QueryHit
// 'penalty' is its penalty
// 'next' is used to explore earlier overlapping fillers
// the decision to emit a QueryHit is made when either there's no next
// or next doesn't overlap the current candidate
// the loop's logic makes sure that at emit time there's no better/earlier filler
// to overlap with the candidate
double penalty = candidateHit.penalty(query, nColumns);
for (next = candidateHit._next; next != null; next = next._next)
if (next._end < candidateHit._begin) { // no overlap
candidateHit.makeQueryHit(query, nColumns, document, penalty);
candidateHit = next;
penalty = candidateHit.penalty(query, nColumns);
}
else {
// !!! can be computed in two steps
double penalty2 = next.penalty(query, nColumns);
if (penalty2 <= penalty) { // prefer next, disregard candidateHit
penalty = penalty2;
candidateHit = next;
}
}
candidateHit.makeQueryHit(query, nColumns, document, penalty);
}
}