restic: extract UidGidInt into separate files

Extract UidGidInt to simplify moving the locking code to the repository.

internal/restic/lock_unix.go

@@ -4,29 +4,11 @@ package restic
 
 import (
 	"os"
-	"os/user"
-	"strconv"
 	"syscall"
 
 	"github.com/restic/restic/internal/debug"
-	"github.com/restic/restic/internal/errors"
 )
 
-// UidGidInt returns uid, gid of the user as a number.
-//
-//nolint:revive // capitalization is correct as is
-func UidGidInt(u *user.User) (uid, gid uint32, err error) {
-	ui, err := strconv.ParseUint(u.Uid, 10, 32)
-	if err != nil {
-		return 0, 0, errors.Errorf("invalid UID %q", u.Uid)
-	}
-	gi, err := strconv.ParseUint(u.Gid, 10, 32)
-	if err != nil {
-		return 0, 0, errors.Errorf("invalid GID %q", u.Gid)
-	}
-	return uint32(ui), uint32(gi), nil
-}
-
 // checkProcess will check if the process retaining the lock
 // exists and responds to SIGHUP signal.
 // Returns true if the process exists and responds.

internal/restic/lock_windows.go

@@ -2,16 +2,10 @@ package restic
 
 import (
 	"os"
-	"os/user"
 
 	"github.com/restic/restic/internal/debug"
 )
 
-// UidGidInt always returns 0 on Windows, since uid isn't numbers
-func UidGidInt(_ *user.User) (uid, gid uint32, err error) {
-	return 0, 0, nil
-}
-
 // checkProcess will check if the process retaining the lock exists.
 // Returns true if the process exists.
 func (l *Lock) processExists() bool {

internal/restic/uid_unix.go

@@ -0,0 +1,25 @@
+//go:build !windows
+
+package restic
+
+import (
+	"os/user"
+	"strconv"
+
+	"github.com/restic/restic/internal/errors"
+)
+
+// UidGidInt returns uid, gid of the user as a number.
+//
+//nolint:revive // capitalization is correct as is
+func UidGidInt(u *user.User) (uid, gid uint32, err error) {
+	ui, err := strconv.ParseUint(u.Uid, 10, 32)
+	if err != nil {
+		return 0, 0, errors.Errorf("invalid UID %q", u.Uid)
+	}
+	gi, err := strconv.ParseUint(u.Gid, 10, 32)
+	if err != nil {
+		return 0, 0, errors.Errorf("invalid GID %q", u.Gid)
+	}
+	return uint32(ui), uint32(gi), nil
+}

internal/restic/uid_windows.go

@@ -0,0 +1,10 @@
+package restic
+
+import (
+	"os/user"
+)
+
+// UidGidInt always returns 0 on Windows, since uid isn't numbers
+func UidGidInt(_ *user.User) (uid, gid uint32, err error) {
+	return 0, 0, nil
+}