--- /dev/null
+package org.apache.lucene.search;
+
+/**
+ * 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 java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.lucene.index.Term;
+import org.apache.lucene.index.TermDocs;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.Explanation.IDFExplanation;
+import org.apache.lucene.util.ReaderUtil;
+import org.apache.lucene.util.ToStringUtils;
+
+/** A Query that matches documents containing a term.
+ This may be combined with other terms with a {@link BooleanQuery}.
+ */
+public class TermQuery extends Query {
+ private Term term;
+
+ private class TermWeight extends Weight {
+ private final Similarity similarity;
+ private float value;
+ private float idf;
+ private float queryNorm;
+ private float queryWeight;
+ private IDFExplanation idfExp;
+ private final Set<Integer> hash;
+
+ public TermWeight(Searcher searcher)
+ throws IOException {
+ this.similarity = getSimilarity(searcher);
+ if (searcher instanceof IndexSearcher) {
+ hash = new HashSet<Integer>();
+ IndexReader ir = ((IndexSearcher)searcher).getIndexReader();
+ final int dfSum[] = new int[1];
+ new ReaderUtil.Gather(ir) {
+ @Override
+ protected void add(int base, IndexReader r) throws IOException {
+ int df = r.docFreq(term);
+ dfSum[0] += df;
+ if (df > 0) {
+ hash.add(r.hashCode());
+ }
+ }
+ }.run();
+
+ idfExp = similarity.idfExplain(term, searcher, dfSum[0]);
+ } else {
+ idfExp = similarity.idfExplain(term, searcher);
+ hash = null;
+ }
+
+ idf = idfExp.getIdf();
+ }
+
+ @Override
+ public String toString() { return "weight(" + TermQuery.this + ")"; }
+
+ @Override
+ public Query getQuery() { return TermQuery.this; }
+
+ @Override
+ public float getValue() { return value; }
+
+ @Override
+ public float sumOfSquaredWeights() {
+ queryWeight = idf * getBoost(); // compute query weight
+ return queryWeight * queryWeight; // square it
+ }
+
+ @Override
+ public void normalize(float queryNorm) {
+ this.queryNorm = queryNorm;
+ queryWeight *= queryNorm; // normalize query weight
+ value = queryWeight * idf; // idf for document
+ }
+
+ @Override
+ public Scorer scorer(IndexReader reader, boolean scoreDocsInOrder, boolean topScorer) throws IOException {
+ // only use the early exit condition if we have an atomic reader, because Lucene 3.x still supports non-atomic readers here:
+ if (hash != null && reader.getSequentialSubReaders() == null && !hash.contains(reader.hashCode())) {
+ return null;
+ }
+
+ TermDocs termDocs = reader.termDocs(term);
+
+ if (termDocs == null)
+ return null;
+
+ return new TermScorer(this, termDocs, similarity, reader.norms(term.field()));
+ }
+
+ @Override
+ public Explanation explain(IndexReader reader, int doc)
+ throws IOException {
+
+ ComplexExplanation result = new ComplexExplanation();
+ result.setDescription("weight("+getQuery()+" in "+doc+"), product of:");
+
+ Explanation expl = new Explanation(idf, idfExp.explain());
+
+ // explain query weight
+ Explanation queryExpl = new Explanation();
+ queryExpl.setDescription("queryWeight(" + getQuery() + "), product of:");
+
+ Explanation boostExpl = new Explanation(getBoost(), "boost");
+ if (getBoost() != 1.0f)
+ queryExpl.addDetail(boostExpl);
+ queryExpl.addDetail(expl);
+
+ Explanation queryNormExpl = new Explanation(queryNorm,"queryNorm");
+ queryExpl.addDetail(queryNormExpl);
+
+ queryExpl.setValue(boostExpl.getValue() *
+ expl.getValue() *
+ queryNormExpl.getValue());
+
+ result.addDetail(queryExpl);
+
+ // explain field weight
+ String field = term.field();
+ ComplexExplanation fieldExpl = new ComplexExplanation();
+ fieldExpl.setDescription("fieldWeight("+term+" in "+doc+
+ "), product of:");
+
+ Explanation tfExplanation = new Explanation();
+ int tf = 0;
+ TermDocs termDocs = reader.termDocs(term);
+ if (termDocs != null) {
+ try {
+ if (termDocs.skipTo(doc) && termDocs.doc() == doc) {
+ tf = termDocs.freq();
+ }
+ } finally {
+ termDocs.close();
+ }
+ tfExplanation.setValue(similarity.tf(tf));
+ tfExplanation.setDescription("tf(termFreq("+term+")="+tf+")");
+ } else {
+ tfExplanation.setValue(0.0f);
+ tfExplanation.setDescription("no matching term");
+ }
+ fieldExpl.addDetail(tfExplanation);
+ fieldExpl.addDetail(expl);
+
+ Explanation fieldNormExpl = new Explanation();
+ byte[] fieldNorms = reader.norms(field);
+ float fieldNorm =
+ fieldNorms!=null ? similarity.decodeNormValue(fieldNorms[doc]) : 1.0f;
+ fieldNormExpl.setValue(fieldNorm);
+ fieldNormExpl.setDescription("fieldNorm(field="+field+", doc="+doc+")");
+ fieldExpl.addDetail(fieldNormExpl);
+
+ fieldExpl.setMatch(Boolean.valueOf(tfExplanation.isMatch()));
+ fieldExpl.setValue(tfExplanation.getValue() *
+ expl.getValue() *
+ fieldNormExpl.getValue());
+
+ result.addDetail(fieldExpl);
+ result.setMatch(fieldExpl.getMatch());
+
+ // combine them
+ result.setValue(queryExpl.getValue() * fieldExpl.getValue());
+
+ if (queryExpl.getValue() == 1.0f)
+ return fieldExpl;
+
+ return result;
+ }
+ }
+
+ /** Constructs a query for the term <code>t</code>. */
+ public TermQuery(Term t) {
+ term = t;
+ }
+
+ /** Returns the term of this query. */
+ public Term getTerm() { return term; }
+
+ @Override
+ public Weight createWeight(Searcher searcher) throws IOException {
+ return new TermWeight(searcher);
+ }
+
+ @Override
+ public void extractTerms(Set<Term> terms) {
+ terms.add(getTerm());
+ }
+
+ /** Prints a user-readable version of this query. */
+ @Override
+ public String toString(String field) {
+ StringBuilder buffer = new StringBuilder();
+ if (!term.field().equals(field)) {
+ buffer.append(term.field());
+ buffer.append(":");
+ }
+ buffer.append(term.text());
+ buffer.append(ToStringUtils.boost(getBoost()));
+ return buffer.toString();
+ }
+
+ /** Returns true iff <code>o</code> is equal to this. */
+ @Override
+ public boolean equals(Object o) {
+ if (!(o instanceof TermQuery))
+ return false;
+ TermQuery other = (TermQuery)o;
+ return (this.getBoost() == other.getBoost())
+ && this.term.equals(other.term);
+ }
+
+ /** Returns a hash code value for this object.*/
+ @Override
+ public int hashCode() {
+ return Float.floatToIntBits(getBoost()) ^ term.hashCode();
+ }
+
+}
fnp / pylucene.git / blobdiff