debug/repair packs/upgrade repo v2: use repository.LoadRaw

This replaces calling the low-level backend.Load() method.

cmd/restic/cmd_debug.go

@@ -316,10 +316,11 @@ func loadBlobs(ctx context.Context, opts DebugExamineOptions, repo restic.Reposi
 	if err != nil {
 		panic(err)
 	}
-	be := repo.Backend()
-	h := backend.Handle{
-		Name: packID.String(),
-		Type: restic.PackFile,
+
+	pack, err := repo.LoadRaw(ctx, restic.PackFile, packID)
+	// allow processing broken pack files
+	if pack == nil {
+		return err
 	}
 
 	wg, ctx := errgroup.WithContext(ctx)
@@ -331,19 +332,11 @@ func loadBlobs(ctx context.Context, opts DebugExamineOptions, repo restic.Reposi
 	wg.Go(func() error {
 		for _, blob := range list {
 			Printf("      loading blob %v at %v (length %v)\n", blob.ID, blob.Offset, blob.Length)
-			buf := make([]byte, blob.Length)
-			err := be.Load(ctx, h, int(blob.Length), int64(blob.Offset), func(rd io.Reader) error {
-				n, err := io.ReadFull(rd, buf)
-				if err != nil {
-					return fmt.Errorf("read error after %d bytes: %v", n, err)
-				}
-				return nil
-			})
-			if err != nil {
-				Warnf("error read: %v\n", err)
+			if int(blob.Offset+blob.Length) > len(pack) {
+				Warnf("skipping truncated blob\n")
 				continue
 			}
-
+			buf := pack[blob.Offset : blob.Offset+blob.Length]
 			key := repo.Key()
 
 			nonce, plaintext := buf[:key.NonceSize()], buf[key.NonceSize():]

cmd/restic/cmd_repair_packs.go

@@ -1,11 +1,11 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"io"
 	"os"
 
-	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/repository"
 	"github.com/restic/restic/internal/restic"
@@ -68,20 +68,17 @@ func runRepairPacks(ctx context.Context, gopts GlobalOptions, term *termstatus.T
 
 	printer.P("saving backup copies of pack files to current folder")
 	for id := range ids {
+		buf, err := repo.LoadRaw(ctx, restic.PackFile, id)
+		// corrupted data is fine
+		if buf == nil {
+			return err
+		}
+
 		f, err := os.OpenFile("pack-"+id.String(), os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0o666)
 		if err != nil {
 			return err
 		}
-
-		err = repo.Backend().Load(ctx, backend.Handle{Type: restic.PackFile, Name: id.String()}, 0, 0, func(rd io.Reader) error {
-			_, err := f.Seek(0, 0)
-			if err != nil {
-				return err
-			}
-			_, err = io.Copy(f, rd)
-			return err
-		})
-		if err != nil {
+		if _, err := io.Copy(f, bytes.NewReader(buf)); err != nil {
 			_ = f.Close()
 			return err
 		}