implement Fileinfo for Windows and non-Windows

internal/internal.go

@@ -176,15 +176,6 @@ func MkdirAll(path string, mode os.FileMode, uid, gid int) error {
 	return nil
 }
 
-// Fileinfo returns syscall fields from a FileInfo object.
-func Fileinfo(fi os.FileInfo) (uid, gid int) {
-	if fi == nil {
-		return -1, -1
-	}
-	stat := fi.Sys().(*syscall.Stat_t)
-	return int(stat.Uid), int(stat.Gid)
-}
-
 // ParseSnapshotPath parses the index from a snapshot filename. Used by path-based replicas.
 func ParseSnapshotPath(s string) (index int, err error) {
 	a := snapshotPathRegex.FindStringSubmatch(s)

internal/internal_unix.go

@@ -0,0 +1,17 @@
+//go:build !windows
+
+package internal
+
+import (
+	"os"
+	"syscall"
+)
+
+// Fileinfo returns syscall fields from a FileInfo object.
+func Fileinfo(fi os.FileInfo) (uid, gid int) {
+	if fi == nil {
+		return -1, -1
+	}
+	stat := fi.Sys().(*syscall.Stat_t)
+	return int(stat.Uid), int(stat.Gid)
+}

internal/internal_windows.go

@@ -0,0 +1,12 @@
+//go:build windows
+
+package internal
+
+import (
+	"os"
+)
+
+// Fileinfo returns syscall fields from a FileInfo object.
+func Fileinfo(fi os.FileInfo) (uid, gid int) {
+	return -1, -1
+}