Merge pull request #76 from blugelabs/fix-score-boosting-issues

fix score boosting issues

query.go

@@ -208,9 +208,10 @@ func (q *BooleanQuery) Searcher(i search.Reader, options search.SearcherOptions)
 	if mustSearcher == nil && shouldSearcher == nil && mustNotSearcher == nil {
 		// if all 3 are nil, return MatchNone
 		return searcher.NewMatchNoneSearcher(i, options)
-	} else if mustSearcher == nil && shouldSearcher != nil && mustNotSearcher == nil {
-		// optimization, if only should searcher, just return it instead
-		return shouldSearcher, nil
+		// } else if mustSearcher == nil && shouldSearcher != nil && mustNotSearcher == nil {
+		//	DISABLED optimization, if only should searcher, just return it instead
+		//  While logically correct, returning the shouldSearcher looses the desired boost.
+		//	return shouldSearcher, nil
 	} else if mustSearcher == nil && shouldSearcher == nil && mustNotSearcher != nil {
 		// if only mustNotSearcher, start with MatchAll
 		var err error
@@ -221,7 +222,7 @@ func (q *BooleanQuery) Searcher(i search.Reader, options search.SearcherOptions)
 	}
 
 	if q.scorer == nil {
-		q.scorer = similarity.NewCompositeSumScorer()
+		q.scorer = similarity.NewCompositeSumScorerWithBoost(q.boost.Value())
 	}
 
 	return searcher.NewBooleanSearcher(mustSearcher, shouldSearcher, mustNotSearcher, q.scorer, options)
@@ -1143,7 +1144,7 @@ func (q *NumericRangeQuery) Searcher(i search.Reader, options search.SearcherOpt
 		field = options.DefaultSearchField
 	}
 	if q.scorer == nil {
-		q.scorer = similarity.ConstantScorer(1)
+		q.scorer = similarity.ConstantScorer(q.boost.Value())
 	}
 	return searcher.NewNumericRangeSearcher(i, q.min, q.max, q.inclusiveMin, q.inclusiveMax, field,
 		q.boost.Value(), q.scorer, similarity.NewCompositeSumScorer(), options)

search/similarity/composite.go

@@ -14,20 +14,32 @@
 
 package similarity
 
-import "github.com/blugelabs/bluge/search"
+import (
+	"github.com/blugelabs/bluge/search"
+)
 
-type CompositeSumScorer struct{}
+type CompositeSumScorer struct {
+	boost float64
+}
 
 func NewCompositeSumScorer() *CompositeSumScorer {
-	return &CompositeSumScorer{}
+	return &CompositeSumScorer{
+		boost: 1.0,
+	}
+}
+
+func NewCompositeSumScorerWithBoost(boost float64) *CompositeSumScorer {
+	return &CompositeSumScorer{
+		boost: boost,
+	}
 }
 
 func (c *CompositeSumScorer) ScoreComposite(constituents []*search.DocumentMatch) float64 {
 	var rv float64
 	for _, constituent := range constituents {
 		rv += constituent.Score
 	}
-	return rv
+	return rv * c.boost
 }
 
 func (c *CompositeSumScorer) ExplainComposite(constituents []*search.DocumentMatch) *search.Explanation {
@@ -37,7 +49,16 @@ func (c *CompositeSumScorer) ExplainComposite(constituents []*search.DocumentMat
 		sum += constituent.Score
 		children = append(children, constituent.Explanation)
 	}
-	return search.NewExplanation(sum,
-		"sum of:",
-		children...)
+	if c.boost == 1 {
+		return search.NewExplanation(sum,
+			"sum of:",
+			children...)
+	}
+
+	return search.NewExplanation(sum*c.boost,
+		"computed as boost * sum",
+		search.NewExplanation(c.boost, "boost"),
+		search.NewExplanation(sum,
+			"sum of:",
+			children...))
 }

search_test.go

@@ -1271,3 +1271,112 @@ func TestAllMatchesWithAggregationIssue31(t *testing.T) {
 	// should not panic with the fix
 	request.AddAggregation("score", aggregations.MaxStartingAt(search.DocumentScore(), 0))
 }
+
+func TestNumericRangeSearchBoost(t *testing.T) {
+	tmpIndexPath := createTmpIndexPath(t)
+	defer cleanupTmpIndexPath(t, tmpIndexPath)
+
+	config := DefaultConfig(tmpIndexPath)
+	indexWriter, err := OpenWriter(config)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	doc := NewDocument("doc").
+		AddField(NewNumericField("age", 25.0))
+
+	batch := NewBatch()
+	batch.Update(doc.ID(), doc)
+
+	if err = indexWriter.Batch(batch); err != nil {
+		t.Fatal(err)
+	}
+
+	indexReader, err := indexWriter.Reader()
+	if err != nil {
+		t.Fatalf("error getting index reader: %v", err)
+	}
+
+	// numeric range query with boost 5.0
+	q := NewNumericRangeQuery(20, 30).SetField("age").SetBoost(5.0)
+	sr := NewTopNSearch(10, q)
+	res, err := indexReader.Search(context.Background(), sr)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	next, err := res.Next()
+	if err != nil {
+		t.Fatalf("error getting first hit")
+	}
+	if next == nil {
+		t.Fatalf("expected at least one hit")
+	}
+	if next.Score != 5.0 {
+		t.Fatalf("expected score to be 5.0, got %f", next.Score)
+	}
+
+	err = indexReader.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = indexWriter.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestBooleanSearchBoost(t *testing.T) {
+	tmpIndexPath := createTmpIndexPath(t)
+	defer cleanupTmpIndexPath(t, tmpIndexPath)
+
+	config := DefaultConfig(tmpIndexPath)
+	indexWriter, err := OpenWriter(config)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	doc := NewDocument("doc").
+		AddField(NewNumericField("age", 25.0))
+
+	batch := NewBatch()
+	batch.Update(doc.ID(), doc)
+
+	if err = indexWriter.Batch(batch); err != nil {
+		t.Fatal(err)
+	}
+
+	indexReader, err := indexWriter.Reader()
+	if err != nil {
+		t.Fatalf("error getting index reader: %v", err)
+	}
+
+	// numeric range query with no boost
+	nrq := NewNumericRangeQuery(20, 30).SetField("age")
+	bq := NewBooleanQuery().AddMust(nrq).SetBoost(3.0)
+	sr := NewTopNSearch(10, bq)
+	res, err := indexReader.Search(context.Background(), sr)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	next, err := res.Next()
+	if err != nil {
+		t.Fatalf("error getting first hit")
+	}
+	if next == nil {
+		t.Fatalf("expected at least one hit")
+	}
+	if next.Score != 3.0 {
+		t.Fatalf("expected score to be 3.0, got %f", next.Score)
+	}
+
+	err = indexReader.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = indexWriter.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+}