WIP: Add config option to enable/disable default fuzzy search

custom/conf/app.example.ini

@@ -1380,6 +1380,10 @@ LEVEL = Info
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
+;; If the indexer type supports fuzzy search use it by default. Is used by issue- and repo-indexer alike.
+;INDEXER_DEFAULT_FUZZY = true
+;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Issue Indexer settings
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;

docs/content/administration/config-cheat-sheet.en-us.md

@@ -467,6 +467,7 @@ relation to port exhaustion.
 
 ## Indexer (`indexer`)
 
+- `INDEXER_DEFAULT_FUZZY`: **true**: If the indexer type supports fuzzy search use it by default. Is used by issue- and repo-indexer alike.
 - `ISSUE_INDEXER_TYPE`: **bleve**: Issue indexer type, currently supported: `bleve`, `db`, `elasticsearch` or `meilisearch`.
 - `ISSUE_INDEXER_CONN_STR`: ****: Issue indexer connection string, available when ISSUE_INDEXER_TYPE is elasticsearch (e.g. http://elastic:password@localhost:9200) or meilisearch (e.g. http://:apikey@localhost:7700)
 - `ISSUE_INDEXER_NAME`: **gitea_issues**: Issue indexer name, available when ISSUE_INDEXER_TYPE is elasticsearch or meilisearch.

modules/indexer/code/bleve/bleve.go

@@ -243,11 +243,17 @@ func (b *Indexer) Search(ctx context.Context, repoIDs []int64, language, keyword
 		prefixQuery := bleve.NewPrefixQuery(keyword)
 		prefixQuery.FieldVal = "Content"
 		keywordQuery = prefixQuery
-	} else {
+	} else if !setting.Indexer.DefaultFuzzy {
 		phraseQuery := bleve.NewMatchPhraseQuery(keyword)
 		phraseQuery.FieldVal = "Content"
 		phraseQuery.Analyzer = repoIndexerAnalyzer
 		keywordQuery = phraseQuery
+	} else {
+		fuzzyQuery := bleve.NewFuzzyQuery(keyword)
+		fuzzyQuery.FieldVal = "Content"
+		fuzzyQuery.SetPrefix(len(keyword))
+		fuzzyQuery.Fuzziness = 2 //Levenshtein distance
+		keywordQuery = fuzzyQuery
 	}
 
 	if len(repoIDs) > 0 {

modules/indexer/code/elasticsearch/elasticsearch.go

@@ -288,6 +288,9 @@ func (b *Indexer) Search(ctx context.Context, repoIDs []int64, language, keyword
 	}
 
 	kwQuery := elastic.NewMultiMatchQuery(keyword, "content").Type(searchType)
+	if !setting.Indexer.DefaultFuzzy {
+		kwQuery = kwQuery.Fuzziness("0")
+	}
 	query := elastic.NewBoolQuery()
 	query = query.Must(kwQuery)
 	if len(repoIDs) > 0 {

modules/indexer/code/internal/indexer.go

@@ -16,6 +16,7 @@ type Indexer interface {
 	internal.Indexer
 	Index(ctx context.Context, repo *repo_model.Repository, sha string, changes *RepoChanges) error
 	Delete(ctx context.Context, repoID int64) error
+	// TODO: use search option struct
 	Search(ctx context.Context, repoIDs []int64, language, keyword string, page, pageSize int, isMatch bool) (int64, []*SearchResult, []*SearchResultLanguages, error)
 }
 

modules/indexer/issues/elasticsearch/elasticsearch.go

@@ -13,6 +13,7 @@ import (
 	indexer_internal "code.gitea.io/gitea/modules/indexer/internal"
 	inner_elasticsearch "code.gitea.io/gitea/modules/indexer/internal/elasticsearch"
 	"code.gitea.io/gitea/modules/indexer/issues/internal"
+	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/olivere/elastic/v7"
 )
@@ -141,7 +142,11 @@ func (b *Indexer) Search(ctx context.Context, options *internal.SearchOptions) (
 	query := elastic.NewBoolQuery()
 
 	if options.Keyword != "" {
-		query.Must(elastic.NewMultiMatchQuery(options.Keyword, "title", "content", "comments"))
+		keywordQuery := elastic.NewMultiMatchQuery(options.Keyword, "title", "content", "comments")
+		if !setting.Indexer.DefaultFuzzy {
+			keywordQuery = keywordQuery.Fuzziness("0")
+		}
+		query.Must(keywordQuery)
 	}
 
 	if len(options.RepoIDs) > 0 {

modules/setting/indexer.go

@@ -16,6 +16,8 @@ import (
 
 // Indexer settings
 var Indexer = struct {
+	DefaultFuzzy bool
+
 	IssueType        string
 	IssuePath        string
 	IssueConnStr     string
@@ -34,6 +36,8 @@ var Indexer = struct {
 	ExcludePatterns      []glob.Glob
 	ExcludeVendored      bool
 }{
+	DefaultFuzzy: true,
+
 	IssueType:        "bleve",
 	IssuePath:        "indexers/issues.bleve",
 	IssueConnStr:     "",
@@ -52,6 +56,9 @@ var Indexer = struct {
 
 func loadIndexerFrom(rootCfg ConfigProvider) {
 	sec := rootCfg.Section("indexer")
+
+	Indexer.DefaultFuzzy = sec.Key("INDEXER_DEFAULT_FUZZY").MustBool(Indexer.DefaultFuzzy)
+
 	Indexer.IssueType = sec.Key("ISSUE_INDEXER_TYPE").MustString("bleve")
 	if Indexer.IssueType == "bleve" {
 		Indexer.IssuePath = filepath.ToSlash(sec.Key("ISSUE_INDEXER_PATH").MustString(filepath.ToSlash(filepath.Join(AppDataPath, "indexers/issues.bleve"))))