package org.apache.lucene.search;
/**
* Copyright 2005 The Apache Software Foundation
*
* 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.
*/
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.search.Similarity;
import org.apache.lucene.search.Weight;
import org.apache.lucene.util.ToStringUtils;
import java.util.Set;
/**
* A query that matches all documents.
*
* @author John Wang
*/
public class MatchAllDocsQuery extends Query {
public MatchAllDocsQuery() {
}
private class MatchAllScorer extends Scorer {
final IndexReader reader;
int id;
final int maxId;
final float score;
MatchAllScorer(IndexReader reader, Similarity similarity, Weight w) {
super(similarity);
this.reader = reader;
id = -1;
maxId = reader.maxDoc() - 1;
score = w.getValue();
}
public Explanation explain(int doc) {
return null; // not called... see MatchAllDocsWeight.explain()
}
public int doc() {
return id;
}
public boolean next() {
while (id < maxId) {
id++;
if (!reader.isDeleted(id)) {
return true;
}
}
return false;
}
public float score() {
return score;
}
public boolean skipTo(int target) {
id = target - 1;
return next();
}
}
private class MatchAllDocsWeight implements Weight {
private Searcher searcher;
private float queryWeight;
private float queryNorm;
public MatchAllDocsWeight(Searcher searcher) {
this.searcher = searcher;
}
public String toString() {
return "weight(" + MatchAllDocsQuery.this + ")";
}
public Query getQuery() {
return MatchAllDocsQuery.this;
}
public float getValue() {
return queryWeight;
}
public float sumOfSquaredWeights() {
queryWeight = getBoost();
return queryWeight * queryWeight;
}
public void normalize(float queryNorm) {
this.queryNorm = queryNorm;
queryWeight *= this.queryNorm;
}
public Scorer scorer(IndexReader reader) {
return new MatchAllScorer(reader, getSimilarity(searcher), this);
}
public Explanation explain(IndexReader reader, int doc) {
// explain query weight
Explanation queryExpl = new Explanation();
queryExpl.setDescription("MatchAllDocsQuery, product of:");
queryExpl.setValue(getValue());
if (getBoost() != 1.0f) {
queryExpl.addDetail(new Explanation(getBoost(),"boost"));
}
queryExpl.addDetail(new Explanation(queryNorm,"queryNorm"));
return queryExpl;
}
}
protected Weight createWeight(Searcher searcher) {
return new MatchAllDocsWeight(searcher);
}
public void extractTerms(Set terms) {
}
public String toString(String field) {
StringBuffer buffer = new StringBuffer();
buffer.append("MatchAllDocsQuery");
buffer.append(ToStringUtils.boost(getBoost()));
return buffer.toString();
}
public boolean equals(Object o) {
if (!(o instanceof MatchAllDocsQuery))
return false;
MatchAllDocsQuery other = (MatchAllDocsQuery) o;
return this.getBoost() == other.getBoost();
}
public int hashCode() {
return Float.floatToIntBits(getBoost()) ^ 0x1AA71190;
}
}
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