org.apache.lucene.queries.MinDocQuery Maven / Gradle / Ivy
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* the Apache License, Version 2.0 (the "License"); you may
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
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package org.apache.lucene.queries;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.ConstantScoreScorer;
import org.apache.lucene.search.ConstantScoreWeight;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Weight;
import java.io.IOException;
import java.util.Objects;
/** A {@link Query} that only matches documents that are greater than or equal
* to a configured doc ID. */
public final class MinDocQuery extends Query {
private final int minDoc;
/** Sole constructor. */
public MinDocQuery(int minDoc) {
this.minDoc = minDoc;
}
@Override
public int hashCode() {
return Objects.hash(classHash(), minDoc);
}
@Override
public boolean equals(Object obj) {
if (sameClassAs(obj) == false) {
return false;
}
MinDocQuery that = (MinDocQuery) obj;
return minDoc == that.minDoc;
}
@Override
public Weight createWeight(IndexSearcher searcher, boolean needsScores) throws IOException {
return new ConstantScoreWeight(this) {
@Override
public Scorer scorer(LeafReaderContext context) throws IOException {
final int maxDoc = context.reader().maxDoc();
if (context.docBase + maxDoc <= minDoc) {
return null;
}
final int segmentMinDoc = Math.max(0, minDoc - context.docBase);
final DocIdSetIterator disi = new DocIdSetIterator() {
int doc = -1;
@Override
public int docID() {
return doc;
}
@Override
public int nextDoc() throws IOException {
return advance(doc + 1);
}
@Override
public int advance(int target) throws IOException {
assert target > doc;
if (doc == -1) {
// skip directly to minDoc
doc = Math.max(target, segmentMinDoc);
} else {
doc = target;
}
if (doc >= maxDoc) {
doc = NO_MORE_DOCS;
}
return doc;
}
@Override
public long cost() {
return maxDoc - segmentMinDoc;
}
};
return new ConstantScoreScorer(this, score(), disi);
}
};
}
@Override
public String toString(String field) {
return "MinDocQuery(minDoc=" + minDoc + ")";
}
}