X-Git-Url: https://git.mdrn.pl/pylucene.git/blobdiff_plain/a2e61f0c04805cfcb8706176758d1283c7e3a55c..aaeed5504b982cf3545252ab528713250aa33eed:/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/function/ValueSourceQuery.java diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/function/ValueSourceQuery.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/function/ValueSourceQuery.java new file mode 100644 index 0000000..3cdb25d --- /dev/null +++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/function/ValueSourceQuery.java @@ -0,0 +1,195 @@ +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}. + *

+ * This query provides a score for each and every undeleted document in the index. + *

+ * 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. + *

+ * Score is set as: Score(doc,query) = query.getBoost()2 * 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 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 o 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()); + } + +}