--- /dev/null
+package org.apache.lucene.search.function;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.index.Term;
+import org.apache.lucene.index.TermDocs;
+import org.apache.lucene.search.*;
+import org.apache.lucene.util.ToStringUtils;
+
+import java.io.IOException;
+import java.util.Set;
+
+/**
+ * Expert: A Query that sets the scores of document to the
+ * values obtained from a {@link org.apache.lucene.search.function.ValueSource ValueSource}.
+ * <p>
+ * This query provides a score for <em>each and every</em> undeleted document in the index.
+ * <p>
+ * The value source can be based on a (cached) value of an indexed field, but it
+ * can also be based on an external source, e.g. values read from an external database.
+ * <p>
+ * Score is set as: Score(doc,query) = query.getBoost()<sup>2</sup> * valueSource(doc).
+ *
+ * @lucene.experimental
+ */
+public class ValueSourceQuery extends Query {
+ ValueSource valSrc;
+
+ /**
+ * Create a value source query
+ * @param valSrc provides the values defines the function to be used for scoring
+ */
+ public ValueSourceQuery(ValueSource valSrc) {
+ this.valSrc=valSrc;
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.Query#rewrite(org.apache.lucene.index.IndexReader) */
+ @Override
+ public Query rewrite(IndexReader reader) throws IOException {
+ return this;
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.Query#extractTerms(java.util.Set) */
+ @Override
+ public void extractTerms(Set<Term> terms) {
+ // no terms involved here
+ }
+
+ class ValueSourceWeight extends Weight {
+ Similarity similarity;
+ float queryNorm;
+ float queryWeight;
+
+ public ValueSourceWeight(Searcher searcher) {
+ this.similarity = getSimilarity(searcher);
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.Weight#getQuery() */
+ @Override
+ public Query getQuery() {
+ return ValueSourceQuery.this;
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.Weight#getValue() */
+ @Override
+ public float getValue() {
+ return queryWeight;
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.Weight#sumOfSquaredWeights() */
+ @Override
+ public float sumOfSquaredWeights() throws IOException {
+ queryWeight = getBoost();
+ return queryWeight * queryWeight;
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.Weight#normalize(float) */
+ @Override
+ public void normalize(float norm) {
+ this.queryNorm = norm;
+ queryWeight *= this.queryNorm;
+ }
+
+ @Override
+ public Scorer scorer(IndexReader reader, boolean scoreDocsInOrder, boolean topScorer) throws IOException {
+ return new ValueSourceScorer(similarity, reader, this);
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.Weight#explain(org.apache.lucene.index.IndexReader, int) */
+ @Override
+ public Explanation explain(IndexReader reader, int doc) throws IOException {
+ DocValues vals = valSrc.getValues(reader);
+ float sc = queryWeight * vals.floatVal(doc);
+
+ Explanation result = new ComplexExplanation(
+ true, sc, ValueSourceQuery.this.toString() + ", product of:");
+
+ result.addDetail(vals.explain(doc));
+ result.addDetail(new Explanation(getBoost(), "boost"));
+ result.addDetail(new Explanation(queryNorm,"queryNorm"));
+ return result;
+ }
+ }
+
+ /**
+ * A scorer that (simply) matches all documents, and scores each document with
+ * the value of the value source in effect. As an example, if the value source
+ * is a (cached) field source, then value of that field in that document will
+ * be used. (assuming field is indexed for this doc, with a single token.)
+ */
+ private class ValueSourceScorer extends Scorer {
+ private final float qWeight;
+ private final DocValues vals;
+ private final TermDocs termDocs;
+ private int doc = -1;
+
+ // constructor
+ private ValueSourceScorer(Similarity similarity, IndexReader reader, ValueSourceWeight w) throws IOException {
+ super(similarity,w);
+ qWeight = w.getValue();
+ // this is when/where the values are first created.
+ vals = valSrc.getValues(reader);
+ termDocs = reader.termDocs(null);
+ }
+
+ @Override
+ public int nextDoc() throws IOException {
+ return doc = termDocs.next() ? termDocs.doc() : NO_MORE_DOCS;
+ }
+
+ @Override
+ public int docID() {
+ return doc;
+ }
+
+ @Override
+ public int advance(int target) throws IOException {
+ return doc = termDocs.skipTo(target) ? termDocs.doc() : NO_MORE_DOCS;
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.Scorer#score() */
+ @Override
+ public float score() throws IOException {
+ return qWeight * vals.floatVal(termDocs.doc());
+ }
+ }
+
+ @Override
+ public Weight createWeight(Searcher searcher) {
+ return new ValueSourceQuery.ValueSourceWeight(searcher);
+ }
+
+ @Override
+ public String toString(String field) {
+ return valSrc.toString() + ToStringUtils.boost(getBoost());
+ }
+
+ /** Returns true if <code>o</code> is equal to this. */
+ @Override
+ public boolean equals(Object o) {
+ if (this == o)
+ return true;
+ if (!super.equals(o))
+ return false;
+ if (getClass() != o.getClass()) {
+ return false;
+ }
+ ValueSourceQuery other = (ValueSourceQuery)o;
+ return this.getBoost() == other.getBoost()
+ && this.valSrc.equals(other.valSrc);
+ }
+
+ /** Returns a hash code value for this object. */
+ @Override
+ public int hashCode() {
+ return (getClass().hashCode() + valSrc.hashCode()) ^ Float.floatToIntBits(getBoost());
+ }
+
+}
fnp / pylucene.git / blobdiff