pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / search / spans / SpanWeight.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/spans/SpanWeight.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/spans/SpanWeight.java
new file mode 100644 (file)
index 0000000..28fd905
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/spans/SpanWeight.java
@@ -0,0 +1,142 @@
+package org.apache.lucene.search.spans;
+
+/**
+ * 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.search.*;
+import org.apache.lucene.search.Explanation.IDFExplanation;
+
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Expert-only.  Public for use by other weight implementations
+ */
+public class SpanWeight extends Weight {
+  protected Similarity similarity;
+  protected float value;
+  protected float idf;
+  protected float queryNorm;
+  protected float queryWeight;
+
+  protected Set<Term> terms;
+  protected SpanQuery query;
+  private IDFExplanation idfExp;
+
+  public SpanWeight(SpanQuery query, Searcher searcher)
+    throws IOException {
+    this.similarity = query.getSimilarity(searcher);
+    this.query = query;
+    
+    terms=new HashSet<Term>();
+    query.extractTerms(terms);
+    
+    idfExp = similarity.idfExplain(terms, searcher);
+    idf = idfExp.getIdf();
+  }
+
+  @Override
+  public Query getQuery() { return query; }
+
+  @Override
+  public float getValue() { return value; }
+
+  @Override
+  public float sumOfSquaredWeights() throws IOException {
+    queryWeight = idf * query.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 {
+    return new SpanScorer(query.getSpans(reader), this, similarity, reader
+        .norms(query.getField()));
+  }
+
+  @Override
+  public Explanation explain(IndexReader reader, int doc)
+    throws IOException {
+
+    ComplexExplanation result = new ComplexExplanation();
+    result.setDescription("weight("+getQuery()+" in "+doc+"), product of:");
+    String field = ((SpanQuery)getQuery()).getField();
+
+    Explanation idfExpl =
+      new Explanation(idf, "idf(" + field + ": " + idfExp.explain() + ")");
+
+    // explain query weight
+    Explanation queryExpl = new Explanation();
+    queryExpl.setDescription("queryWeight(" + getQuery() + "), product of:");
+
+    Explanation boostExpl = new Explanation(getQuery().getBoost(), "boost");
+    if (getQuery().getBoost() != 1.0f)
+      queryExpl.addDetail(boostExpl);
+    queryExpl.addDetail(idfExpl);
+
+    Explanation queryNormExpl = new Explanation(queryNorm,"queryNorm");
+    queryExpl.addDetail(queryNormExpl);
+
+    queryExpl.setValue(boostExpl.getValue() *
+                       idfExpl.getValue() *
+                       queryNormExpl.getValue());
+
+    result.addDetail(queryExpl);
+
+    // explain field weight
+    ComplexExplanation fieldExpl = new ComplexExplanation();
+    fieldExpl.setDescription("fieldWeight("+field+":"+query.toString(field)+
+                             " in "+doc+"), product of:");
+
+    Explanation tfExpl = ((SpanScorer)scorer(reader, true, false)).explain(doc);
+    fieldExpl.addDetail(tfExpl);
+    fieldExpl.addDetail(idfExpl);
+
+    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(tfExpl.isMatch()));
+    fieldExpl.setValue(tfExpl.getValue() *
+                       idfExpl.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;
+  }
+}