[LUCENE-1427] QueryWrapperFilter should not do scoring

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.9
• Component/s: core/search
• Lucene Fields: New
• Assignee: Michael McCandless
• Reporter: Michael McCandless
• Created: 22/Oct/08 13:19
• Updated: 28/Aug/22 11:54
• Resolved: 31/Oct/08 16:18

Description

The purpose of QueryWrapperFilter is to simply filter to include the docIDs that match the query.

Its implementation is wasteful now because it computes scores for those matching docs even though the score is unused. We could fix this by getting a Scorer and iterating through the docs without asking for the score:

Index: src/java/org/apache/lucene/search/QueryWrapperFilter.java
===================================================================
--- src/java/org/apache/lucene/search/QueryWrapperFilter.java	(revision 707060)
+++ src/java/org/apache/lucene/search/QueryWrapperFilter.java	(working copy)
@@ -62,11 +62,9 @@
   public DocIdSet getDocIdSet(IndexReader reader) throws IOException {
     final OpenBitSet bits = new OpenBitSet(reader.maxDoc());
 
-    new IndexSearcher(reader).search(query, new HitCollector() {
-      public final void collect(int doc, float score) {
-        bits.set(doc);  // set bit for hit
-      }
-    });
+    final Scorer scorer = query.weight(new IndexSearcher(reader)).scorer(reader);
+    while(scorer.next())
+      bits.set(scorer.doc());
     return bits;
   }

Maybe I'm missing something, but this seams like a simple win?