Default to sqlite piece completion for dir if cgo enabled

storage/default-dir-piece-completion-boltdb.go

@@ -0,0 +1,8 @@
+//go:build !cgo
+// +build !cgo
+
+package storage
+
+func NewDefaultPieceCompletionForDir(dir string) (PieceCompletion, error) {
+	return NewBoltPieceCompletion(dir)
+}

storage/default-dir-piece-completion-sqlite.go

@@ -0,0 +1,8 @@
+//go:build cgo
+// +build cgo
+
+package storage
+
+func NewDefaultPieceCompletionForDir(dir string) (PieceCompletion, error) {
+	return NewSqlitePieceCompletion(dir)
+}

storage/piece-completion.go

@@ -18,7 +18,7 @@ type PieceCompletion interface {
 }
 
 func pieceCompletionForDir(dir string) (ret PieceCompletion) {
-	ret, err := NewBoltPieceCompletion(dir)
+	ret, err := NewDefaultPieceCompletionForDir(dir)
 	if err != nil {
 		log.Printf("couldn't open piece completion db in %q: %s", dir, err)
 		ret = NewMapPieceCompletion()