restic/internal/repository/repair_pack.go
Michael Eischer 5f7b48e65f index: replace Save() method with Rewrite and SaveFallback
Rewrite implements a streaming rewrite of the index that excludes the
given packs. For this it loads all index files from the repository and
only modifies those that require changes. This will reduce the index
churn when running prune. Rewrite does not require the in-memory index
and thus can drop it to significantly reduce the memory usage.

However, `prune --unsafe-recovery` cannot use this strategy and requires
a separate method to save the whole in-memory index. This is now handled
using SaveFallback.
2024-05-24 21:33:17 +02:00

72 lines
1.8 KiB
Go

package repository
import (
"context"
"errors"
"io"
"github.com/restic/restic/internal/restic"
"github.com/restic/restic/internal/ui/progress"
"golang.org/x/sync/errgroup"
)
func RepairPacks(ctx context.Context, repo *Repository, ids restic.IDSet, printer progress.Printer) error {
wg, wgCtx := errgroup.WithContext(ctx)
repo.StartPackUploader(wgCtx, wg)
printer.P("salvaging intact data from specified pack files")
bar := printer.NewCounter("pack files")
bar.SetMax(uint64(len(ids)))
defer bar.Done()
wg.Go(func() error {
// examine all data the indexes have for the pack file
for b := range repo.ListPacksFromIndex(wgCtx, ids) {
blobs := b.Blobs
if len(blobs) == 0 {
printer.E("no blobs found for pack %v", b.PackID)
bar.Add(1)
continue
}
err := repo.LoadBlobsFromPack(wgCtx, b.PackID, blobs, func(blob restic.BlobHandle, buf []byte, err error) error {
if err != nil {
printer.E("failed to load blob %v: %v", blob.ID, err)
return nil
}
id, _, _, err := repo.SaveBlob(wgCtx, blob.Type, buf, restic.ID{}, true)
if !id.Equal(blob.ID) {
panic("pack id mismatch during upload")
}
return err
})
// ignore truncated file parts
if err != nil && !errors.Is(err, io.ErrUnexpectedEOF) {
return err
}
bar.Add(1)
}
return repo.Flush(wgCtx)
})
err := wg.Wait()
bar.Done()
if err != nil {
return err
}
// remove salvaged packs from index
err = rewriteIndexFiles(ctx, repo, ids, nil, nil, printer)
if err != nil {
return err
}
// cleanup
printer.P("removing salvaged pack files")
// if we fail to delete the damaged pack files, then prune will remove them later on
bar = printer.NewCounter("files deleted")
_ = restic.ParallelRemove(ctx, repo, ids, restic.PackFile, nil, bar)
bar.Done()
return nil
}