Refactor out file scanner into separate package

cmd/syncthing/tempname.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"fmt"
+	"path"
+	"path/filepath"
+	"runtime"
+	"strings"
+)
+
+type tempNamer struct {
+	prefix string
+}
+
+var defTempNamer = tempNamer{".syncthing"}
+
+func (t tempNamer) IsTemporary(name string) bool {
+	if runtime.GOOS == "windows" {
+		name = filepath.ToSlash(name)
+	}
+	return strings.HasPrefix(path.Base(name), t.prefix)
+}
+
+func (t tempNamer) TempName(name string) string {
+	tdir := path.Dir(name)
+	tname := fmt.Sprintf("%s.%s", t.prefix, path.Base(name))
+	return path.Join(tdir, tname)
+}