Merge pull request #398 from slavikm/master

Make facets much faster

index/index.go

@@ -77,6 +77,7 @@ type IndexReader interface {
 
 	Document(id string) (*document.Document, error)
 	DocumentFieldTerms(id string) (FieldTerms, error)
+	DocumentFieldTermsForFields(id string, fields []string) (FieldTerms, error)
 
 	Fields() ([]string, error)
 

index/upside_down/index_reader.go

@@ -10,6 +10,8 @@
 package upside_down
 
 import (
+	"fmt"
+
 	"github.com/blevesearch/bleve/document"
 	"github.com/blevesearch/bleve/index"
 	"github.com/blevesearch/bleve/index/store"
@@ -110,6 +112,33 @@ func (i *IndexReader) DocumentFieldTerms(id string) (index.FieldTerms, error) {
 	return rv, nil
 }
 
+func (i *IndexReader) DocumentFieldTermsForFields(id string, fields []string) (index.FieldTerms, error) {
+	back, err := i.index.backIndexRowForDoc(i.kvreader, id)
+	if err != nil {
+		return nil, err
+	}
+	rv := make(index.FieldTerms, len(fields))
+	fieldsMap := make(map[uint16]string, len(fields))
+	for _, f := range fields {
+		id, ok := i.index.fieldCache.FieldNamed(f, false)
+		if !ok {
+			return nil, fmt.Errorf("Field %s was not found in cache", f)
+		}
+		fieldsMap[id] = f
+	}
+	for _, entry := range back.termEntries {
+		if field, ok := fieldsMap[uint16(*entry.Field)]; ok {
+			terms, ok := rv[field]
+			if !ok {
+				terms = make([]string, 0)
+			}
+			terms = append(terms, *entry.Term)
+			rv[field] = terms
+		}
+	}
+	return rv, nil
+}
+
 func (i *IndexReader) Fields() (fields []string, err error) {
 	fields = make([]string, 0)
 	it := i.kvreader.PrefixIterator([]byte{'f'})

search/facets/facet_builder_datetime.go

@@ -49,6 +49,10 @@ func (fb *DateTimeFacetBuilder) AddRange(name string, start, end time.Time) {
 	fb.ranges[name] = &r
 }
 
+func (fb *DateTimeFacetBuilder) Field() string {
+	return fb.field
+}
+
 func (fb *DateTimeFacetBuilder) Update(ft index.FieldTerms) {
 	terms, ok := ft[fb.field]
 	if ok {

search/facets/facet_builder_numeric.go

@@ -48,6 +48,10 @@ func (fb *NumericFacetBuilder) AddRange(name string, min, max *float64) {
 	fb.ranges[name] = &r
 }
 
+func (fb *NumericFacetBuilder) Field() string {
+	return fb.field
+}
+
 func (fb *NumericFacetBuilder) Update(ft index.FieldTerms) {
 	terms, ok := ft[fb.field]
 	if ok {

search/facets/facet_builder_terms.go

@@ -32,6 +32,10 @@ func NewTermsFacetBuilder(field string, size int) *TermsFacetBuilder {
 	}
 }
 
+func (fb *TermsFacetBuilder) Field() string {
+	return fb.field
+}
+
 func (fb *TermsFacetBuilder) Update(ft index.FieldTerms) {
 	terms, ok := ft[fb.field]
 	if ok {

search/facets_builder.go

@@ -18,6 +18,7 @@ import (
 type FacetBuilder interface {
 	Update(index.FieldTerms)
 	Result() *FacetResult
+	Field() string
 }
 
 type FacetsBuilder struct {
@@ -37,7 +38,11 @@ func (fb *FacetsBuilder) Add(name string, facetBuilder FacetBuilder) {
 }
 
 func (fb *FacetsBuilder) Update(docMatch *DocumentMatch) error {
-	fieldTerms, err := fb.indexReader.DocumentFieldTerms(docMatch.ID)
+	var fields []string
+	for _, facetBuilder := range fb.facets {
+		fields = append(fields, facetBuilder.Field())
+	}
+	fieldTerms, err := fb.indexReader.DocumentFieldTermsForFields(docMatch.ID, fields)
 	if err != nil {
 		return err
 	}