Upgrade vellum and accommodate change to Reader interfaces

fuzzy.go

@@ -14,7 +14,7 @@
 
 package sear
 
-func LevenshteinDistanceMaxReuseSlice(a, b string, max int, d []int) (dist int, exceeded bool, reuse []int) {
+func levenshteinDistanceMaxReuseSlice(a, b string, max int, d []int) (dist int, exceeded bool, reuse []int) {
 	la := len(a)
 	lb := len(b)
 

fuzzy_test.go

@@ -70,13 +70,13 @@ func TestFuzzyMatch(t *testing.T) {
 		test := test
 		t.Run(fmt.Sprintf("%s-%d", test.searchTerm, test.fuzziness), func(t *testing.T) {
 			for _, sm := range test.shouldMatch {
-				dist, exceeded, _ := LevenshteinDistanceMaxReuseSlice(test.searchTerm, sm, test.fuzziness, nil)
+				dist, exceeded, _ := levenshteinDistanceMaxReuseSlice(test.searchTerm, sm, test.fuzziness, nil)
 				if dist > test.fuzziness || exceeded {
 					t.Errorf("expected %s to match, did not", sm)
 				}
 			}
 			for _, snm := range test.shouldNotMatch {
-				dist, exceeded, _ := LevenshteinDistanceMaxReuseSlice(test.searchTerm, snm, test.fuzziness, nil)
+				dist, exceeded, _ := levenshteinDistanceMaxReuseSlice(test.searchTerm, snm, test.fuzziness, nil)
 				if dist <= test.fuzziness && !exceeded {
 					t.Errorf("expected %s not to match, did", snm)
 				}

go.mod

@@ -4,7 +4,7 @@ go 1.21
 
 require (
 	github.com/blevesearch/bleve_index_api v1.2.1
-	github.com/blevesearch/vellum v1.0.10
+	github.com/blevesearch/vellum v1.1.0
 )
 
 require (

go.sum

@@ -4,7 +4,7 @@ github.com/blevesearch/bleve_index_api v1.2.1 h1:IuXwLvmyp7I7+e0FOA68gcHHLfzSQ4A
 github.com/blevesearch/bleve_index_api v1.2.1/go.mod h1:rKQDl4u51uwafZxFrPD1R7xFOwKnzZW7s/LSeK4lgo0=
 github.com/blevesearch/mmap-go v1.0.4 h1:OVhDhT5B/M1HNPpYPBKIEJaD0F3Si+CrEKULGCDPWmc=
 github.com/blevesearch/mmap-go v1.0.4/go.mod h1:EWmEAOmdAS9z/pi/+Toxu99DnsbhG1TIxUoRmJw/pSs=
-github.com/blevesearch/vellum v1.0.10 h1:HGPJDT2bTva12hrHepVT3rOyIKFFF4t7Gf6yMxyMIPI=
-github.com/blevesearch/vellum v1.0.10/go.mod h1:ul1oT0FhSMDIExNjIxHqJoGpVrBpKCdgDQNxfqgJt7k=
+github.com/blevesearch/vellum v1.1.0 h1:CinkGyIsgVlYf8Y2LUQHvdelgXr6PYuvoDIajq6yR9w=
+github.com/blevesearch/vellum v1.1.0/go.mod h1:QgwWryE8ThtNPxtgWJof5ndPfx0/YMBh+W2weHKPw8Y=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a h1:dGzPydgVsqGcTRVwiLJ1jVbufYwmzD3LfVPLKsKg+0k=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

reader.go

@@ -21,9 +21,9 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/blevesearch/vellum"
-
 	index "github.com/blevesearch/bleve_index_api"
+	"github.com/blevesearch/vellum"
+	vellev "github.com/blevesearch/vellum/levenshtein"
 	velreg "github.com/blevesearch/vellum/regexp"
 )
 
@@ -150,29 +150,41 @@ func automatonMatch(la vellum.Automaton, termStr string) bool {
 }
 
 func (r *Reader) FieldDictRegexp(field, regexStr string) (index.FieldDict, error) {
+	fd, _, err := r.fieldDictRegexp(field, regexStr)
+	return fd, err
+}
+
+func (r *Reader) FieldDictRegexpAutomaton(field, regexStr string) (
+	index.FieldDict, index.RegexAutomaton, error) {
+	return r.fieldDictRegexp(field, regexStr)
+}
+
+func (r *Reader) fieldDictRegexp(field, regexStr string) (
+	index.FieldDict, index.RegexAutomaton, error) {
 	regex, cached := r.velregCache[regexStr]
 	if !cached {
 		var err error
 		regex, err = velreg.New(regexStr)
 		if err != nil {
-			return nil, fmt.Errorf("error compiling regexp: %v", err)
+			return nil, nil, fmt.Errorf("error compiling regexp: %v", err)
 		}
 		r.velregCache[regexStr] = regex
 	}
 	if r.s.doc == nil {
-		return fieldDictEmpty, nil
+		return fieldDictEmpty, regex, nil
 	}
 	fieldSortedTerms, err := r.s.doc.SortedTermsForField(field)
 	if err != nil {
 		// only error is field doesn't exist in doc
-		return fieldDictEmpty, nil
+		return fieldDictEmpty, regex, nil
 	}
 	return NewFieldDictWithTerms(fieldSortedTerms, func(s string) bool {
 		return automatonMatch(regex, s)
-	}), nil
+	}), regex, nil
 }
 
-func (r *Reader) FieldDictFuzzy(field, term string, fuzziness int, prefix string) (index.FieldDict, error) {
+func (r *Reader) FieldDictFuzzy(field, term string, fuzziness int, prefix string) (
+	index.FieldDict, error) {
 	if r.s.doc == nil {
 		return fieldDictEmpty, nil
 	}
@@ -184,14 +196,30 @@ func (r *Reader) FieldDictFuzzy(field, term string, fuzziness int, prefix string
 	return NewFieldDictWithTerms(fieldSortedTerms, func(indexTerm string) bool {
 		var dist int
 		var exceeded bool
-		dist, exceeded, r.levSlice = LevenshteinDistanceMaxReuseSlice(term, indexTerm, fuzziness, r.levSlice)
+		dist, exceeded, r.levSlice = levenshteinDistanceMaxReuseSlice(
+			term, indexTerm, fuzziness, r.levSlice)
 		if dist <= fuzziness && !exceeded {
 			return true
 		}
 		return false
 	}), nil
 }
 
+func (r *Reader) FieldDictFuzzyAutomaton(field, term string, fuzziness int, prefix string) (
+	index.FieldDict, index.FuzzyAutomaton, error) {
+	a, err := getLevAutomaton(term, uint8(fuzziness))
+	if err != nil {
+		return nil, nil, err
+	}
+	var fa index.FuzzyAutomaton
+	if vfa, ok := a.(vellum.FuzzyAutomaton); ok {
+		fa = vfa
+	}
+
+	fd, err := r.FieldDictFuzzy(field, term, fuzziness, prefix)
+	return fd, fa, err
+}
+
 func (r *Reader) FieldDictContains(field string) (index.FieldDictContains, error) {
 	if r.s.doc == nil {
 		return fieldDictContainsEmpty, nil
@@ -253,3 +281,30 @@ func (r *Reader) InternalID(id string) (index.IndexInternalID, error) {
 func (r *Reader) Close() error {
 	return nil
 }
+
+// -----------------------------------------------------------------------------
+
+// re usable, threadsafe levenshtein builders
+var lb1, lb2 *vellev.LevenshteinAutomatonBuilder
+
+func init() {
+	var err error
+	lb1, err = vellev.NewLevenshteinAutomatonBuilder(1, true)
+	if err != nil {
+		panic(fmt.Errorf("Levenshtein automaton ed1 builder err: %v", err))
+	}
+	lb2, err = vellev.NewLevenshteinAutomatonBuilder(2, true)
+	if err != nil {
+		panic(fmt.Errorf("Levenshtein automaton ed2 builder err: %v", err))
+	}
+}
+
+// https://github.com/blevesearch/bleve/blob/77458c4/index/scorch/snapshot_index.go#L291
+func getLevAutomaton(term string, fuzziness uint8) (vellum.Automaton, error) {
+	if fuzziness == 1 {
+		return lb1.BuildDfa(term, fuzziness)
+	} else if fuzziness == 2 {
+		return lb2.BuildDfa(term, fuzziness)
+	}
+	return nil, fmt.Errorf("fuzziness exceeds the max limit")
+}