/*
* #!
* Ontopia Engine
* #-
* Copyright (C) 2001 - 2013 The Ontopia Project
* #-
* 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 net.ontopia.topicmaps.query.impl.basic;
import net.ontopia.topicmaps.core.OccurrenceIF;
import net.ontopia.topicmaps.core.TopicIF;
import net.ontopia.topicmaps.core.TopicMapIF;
import net.ontopia.topicmaps.query.core.InvalidQueryException;
import net.ontopia.topicmaps.query.impl.utils.Prefetcher;
import net.ontopia.topicmaps.query.impl.utils.PredicateDrivenCostEstimator;
/**
* INTERNAL: Implements the 'occurrence' predicate.
*/
public class OccurrencePredicate implements BasicPredicateIF {
protected TopicMapIF topicmap;
public OccurrencePredicate(TopicMapIF topicmap) {
this.topicmap = topicmap;
}
public String getName() {
return "occurrence";
}
public String getSignature() {
return "t o";
}
public int getCost(boolean[] boundparams) {
if (boundparams[0] && boundparams[1])
return PredicateDrivenCostEstimator.FILTER_RESULT;
else if (boundparams[0] && !boundparams[1])
return PredicateDrivenCostEstimator.SMALL_RESULT;
else if (!boundparams[0] && boundparams[1])
return PredicateDrivenCostEstimator.SINGLE_RESULT;
else
return PredicateDrivenCostEstimator.WHOLE_TM_RESULT;
}
public QueryMatches satisfy(QueryMatches matches, Object[] arguments)
throws InvalidQueryException {
int topicix = matches.getIndex(arguments[0]);
int occix = matches.getIndex(arguments[1]);
if (matches.data[0][occix] == null && matches.data[0][topicix] != null) {
Prefetcher.prefetch(topicmap, matches, topicix,
Prefetcher.TopicIF,
Prefetcher.TopicIF_occurrences, false);
return PredicateUtils.objectToMany(matches, topicix, occix, TopicIF.class,
PredicateUtils.TOPIC_TO_OCCURRENCE, null);
} else if (matches.data[0][occix] != null && matches.data[0][topicix] == null) {
Prefetcher.prefetch(topicmap, matches, occix,
Prefetcher.OccurrenceIF,
Prefetcher.OccurrenceIF_topic, false);
return occurrenceToTopic(matches, topicix, occix);
} else if (matches.data[0][occix] != null && matches.data[0][topicix] != null) {
Prefetcher.prefetch(topicmap, matches, occix,
Prefetcher.OccurrenceIF,
Prefetcher.OccurrenceIF_topic, false);
/* using opposite order here of what the predicate accepts, because
it's faster this way */
return PredicateUtils.filter(matches, occix, topicix,
OccurrenceIF.class, TopicIF.class,
PredicateUtils.FILTER_OCCURRENCE);
} else {
Prefetcher.prefetch(topicmap, matches, topicix,
Prefetcher.TopicIF,
Prefetcher.TopicIF_occurrences, false);
return PredicateUtils.generateFromCollection(matches, topicix, occix,
topicmap.getTopics(),
PredicateUtils.GENERATE_OCCURRENCE);
}
}
// internal
private QueryMatches occurrenceToTopic(QueryMatches matches, int topicix, int occix) {
QueryMatches result = new QueryMatches(matches);
for (int ix = 0; ix <= matches.last; ix++) {
if (!(matches.data[ix][occix] instanceof OccurrenceIF))
continue;
if (result.last+1 == result.size)
result.increaseCapacity();
result.last++;
Object[] newRow = (Object[]) matches.data[ix].clone();
newRow[topicix] = ((OccurrenceIF) newRow[occix]).getTopic();
result.data[result.last] = newRow;
}
return result;
}
private QueryMatches filter(QueryMatches matches, int topicix, int occix) {
int nextix = 0;
for (int ix = 0; ix <= matches.last; ix++) {
if (!(matches.data[ix][occix] instanceof OccurrenceIF) ||
!(matches.data[ix][topicix] instanceof TopicIF))
continue;
OccurrenceIF occ = (OccurrenceIF) matches.data[ix][occix];
TopicIF topic = (TopicIF) matches.data[ix][topicix];
if (occ.getTopic().equals(topic))
matches.data[nextix++] = matches.data[ix];
}
matches.last = nextix - 1;
return matches;
}
}