Update server dependencies

vendor/github.com/blevesearch/bleve/search/searcher/search_fuzzy.go

@@ -15,13 +15,22 @@
 package searcher
 
 import (
+	"fmt"
+
 	"github.com/blevesearch/bleve/index"
 	"github.com/blevesearch/bleve/search"
 )
 
+var MaxFuzziness = 2
+
 func NewFuzzySearcher(indexReader index.IndexReader, term string,
 	prefix, fuzziness int, field string, boost float64,
 	options search.SearcherOptions) (search.Searcher, error) {
+
+	if fuzziness > MaxFuzziness {
+		return nil, fmt.Errorf("fuzziness exceeds max (%d)", MaxFuzziness)
+	}
+
 	// Note: we don't byte slice the term for a prefix because of runes.
 	prefixTerm := ""
 	for i, r := range term {
@@ -31,7 +40,6 @@ func NewFuzzySearcher(indexReader index.IndexReader, term string,
 			break
 		}
 	}
-
 	candidateTerms, err := findFuzzyCandidateTerms(indexReader, term, fuzziness,
 		field, prefixTerm)
 	if err != nil {
@@ -49,6 +57,26 @@ func findFuzzyCandidateTerms(indexReader index.IndexReader, term string,
 	if len(prefixTerm) > 0 {
 		fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
 	} else {
+		// in case of advanced reader implementations directly call
+		// the levenshtein automaton based iterator to collect the
+		// candidate terms
+		if ir, ok := indexReader.(index.IndexReaderFuzzy); ok {
+			fieldDict, err = ir.FieldDictFuzzy(field, []byte(term), fuzziness)
+			if err != nil {
+				return rv, err
+			}
+			defer func() {
+				if cerr := fieldDict.Close(); cerr != nil && err == nil {
+					err = cerr
+				}
+			}()
+			tfd, err := fieldDict.Next()
+			for err == nil && tfd != nil {
+				rv = append(rv, tfd.Term)
+				tfd, err = fieldDict.Next()
+			}
+			return rv, err
+		}
 		fieldDict, err = indexReader.FieldDict(field)
 	}
 	defer func() {
@@ -58,9 +86,12 @@ func findFuzzyCandidateTerms(indexReader index.IndexReader, term string,
 	}()
 
 	// enumerate terms and check levenshtein distance
+	var reuse []int
 	tfd, err := fieldDict.Next()
 	for err == nil && tfd != nil {
-		ld, exceeded := search.LevenshteinDistanceMax(term, tfd.Term, fuzziness)
+		var ld int
+		var exceeded bool
+		ld, exceeded, reuse = search.LevenshteinDistanceMaxReuseSlice(term, tfd.Term, fuzziness, reuse)
 		if !exceeded && ld <= fuzziness {
 			rv = append(rv, tfd.Term)
 			if tooManyClauses(len(rv)) {