Golang Repository.Backend方法代码示例

func packIDTester(repo restic.Repository, inChan <-chan restic.ID, errChan chan<- error, wg *sync.WaitGroup, done <-chan struct{}) {
	debug.Log("worker start")
	defer debug.Log("worker done")

	defer wg.Done()

	for id := range inChan {
		ok, err := repo.Backend().Test(restic.DataFile, id.String())
		if err != nil {
			err = PackError{ID: id, Err: err}
		} else {
			if !ok {
				err = PackError{ID: id, Err: errors.New("does not exist")}
			}
		}

		if err != nil {
			debug.Log("error checking for pack %s: %v", id.Str(), err)
			select {
			case <-done:
				return
			case errChan <- err:
			}

			continue
		}

		debug.Log("pack %s exists", id.Str())
	}
}

func countPacks(repo restic.Repository, t restic.FileType) (n uint) {
	for _ = range repo.Backend().List(t, nil) {
		n++
	}

	return n
}

// RebuildIndex lists all packs in the repo, writes a new index and removes all
// old indexes. This operation should only be done with an exclusive lock in
// place.
func RebuildIndex(repo restic.Repository) error {
	debug.Log("start rebuilding index")

	done := make(chan struct{})
	defer close(done)

	ch := make(chan worker.Job)
	go list.AllPacks(repo, ch, done)

	idx := NewIndex()
	for job := range ch {
		id := job.Data.(restic.ID)

		if job.Error != nil {
			fmt.Fprintf(os.Stderr, "error for pack %v: %v\n", id, job.Error)
			continue
		}

		res := job.Result.(list.Result)

		for _, entry := range res.Entries() {
			pb := restic.PackedBlob{
				Blob:   entry,
				PackID: res.PackID(),
			}
			idx.Store(pb)
		}
	}

	oldIndexes := restic.NewIDSet()
	for id := range repo.List(restic.IndexFile, done) {
		idx.AddToSupersedes(id)
		oldIndexes.Insert(id)
	}

	id, err := SaveIndex(repo, idx)
	if err != nil {
		debug.Log("error saving index: %v", err)
		return err
	}
	debug.Log("new index saved as %v", id.Str())

	for indexID := range oldIndexes {
		err := repo.Backend().Remove(restic.IndexFile, indexID.String())
		if err != nil {
			fmt.Fprintf(os.Stderr, "unable to remove index %v: %v\n", indexID.Str(), err)
		}
	}

	return nil
}

// checkPack reads a pack and checks the integrity of all blobs.
func checkPack(r restic.Repository, id restic.ID) error {
	debug.Log("checking pack %v", id.Str())
	h := restic.Handle{Type: restic.DataFile, Name: id.String()}
	buf, err := backend.LoadAll(r.Backend(), h, nil)
	if err != nil {
		return err
	}

	hash := restic.Hash(buf)
	if !hash.Equal(id) {
		debug.Log("Pack ID does not match, want %v, got %v", id.Str(), hash.Str())
		return errors.Errorf("Pack ID does not match, want %v, got %v", id.Str(), hash.Str())
	}

	blobs, err := pack.List(r.Key(), bytes.NewReader(buf), int64(len(buf)))
	if err != nil {
		return err
	}

	var errs []error
	for i, blob := range blobs {
		debug.Log("  check blob %d: %v", i, blob.ID.Str())

		plainBuf := make([]byte, blob.Length)
		n, err := crypto.Decrypt(r.Key(), plainBuf, buf[blob.Offset:blob.Offset+blob.Length])
		if err != nil {
			debug.Log("  error decrypting blob %v: %v", blob.ID.Str(), err)
			errs = append(errs, errors.Errorf("blob %v: %v", i, err))
			continue
		}
		plainBuf = plainBuf[:n]

		hash := restic.Hash(plainBuf)
		if !hash.Equal(blob.ID) {
			debug.Log("  Blob ID does not match, want %v, got %v", blob.ID.Str(), hash.Str())
			errs = append(errs, errors.Errorf("Blob ID does not match, want %v, got %v", blob.ID.Str(), hash.Str()))
			continue
		}
	}

	if len(errs) > 0 {
		return errors.Errorf("pack %v contains %v errors: %v", id.Str(), len(errs), errs)
	}

	return nil
}

// loadSnapshotTreeIDs loads all snapshots from backend and returns the tree IDs.
func loadSnapshotTreeIDs(repo restic.Repository) (restic.IDs, []error) {
	var trees struct {
		IDs restic.IDs
		sync.Mutex
	}

	var errs struct {
		errs []error
		sync.Mutex
	}

	snapshotWorker := func(strID string, done <-chan struct{}) error {
		id, err := restic.ParseID(strID)
		if err != nil {
			return err
		}

		debug.Log("load snapshot %v", id.Str())

		treeID, err := loadTreeFromSnapshot(repo, id)
		if err != nil {
			errs.Lock()
			errs.errs = append(errs.errs, err)
			errs.Unlock()
			return nil
		}

		debug.Log("snapshot %v has tree %v", id.Str(), treeID.Str())
		trees.Lock()
		trees.IDs = append(trees.IDs, treeID)
		trees.Unlock()

		return nil
	}

	err := repository.FilesInParallel(repo.Backend(), restic.SnapshotFile, defaultParallelism, snapshotWorker)
	if err != nil {
		errs.errs = append(errs.errs, err)
	}

	return trees.IDs, errs.errs
}

// Repack takes a list of packs together with a list of blobs contained in
// these packs. Each pack is loaded and the blobs listed in keepBlobs is saved
// into a new pack. Afterwards, the packs are removed. This operation requires
// an exclusive lock on the repo.
func Repack(repo restic.Repository, packs restic.IDSet, keepBlobs restic.BlobSet) (err error) {
	debug.Log("repacking %d packs while keeping %d blobs", len(packs), len(keepBlobs))

	buf := make([]byte, 0, maxPackSize)
	for packID := range packs {
		// load the complete pack
		h := restic.Handle{Type: restic.DataFile, Name: packID.String()}

		l, err := repo.Backend().Load(h, buf[:cap(buf)], 0)
		if errors.Cause(err) == io.ErrUnexpectedEOF {
			err = nil
			buf = buf[:l]
		}

		if err != nil {
			return err
		}

		debug.Log("pack %v loaded (%d bytes)", packID.Str(), len(buf))

		blobs, err := pack.List(repo.Key(), bytes.NewReader(buf), int64(len(buf)))
		if err != nil {
			return err
		}

		debug.Log("processing pack %v, blobs: %v", packID.Str(), len(blobs))
		var plaintext []byte
		for _, entry := range blobs {
			h := restic.BlobHandle{ID: entry.ID, Type: entry.Type}
			if !keepBlobs.Has(h) {
				continue
			}

			debug.Log("  process blob %v", h)

			ciphertext := buf[entry.Offset : entry.Offset+entry.Length]
			plaintext = plaintext[:len(plaintext)]
			if len(plaintext) < len(ciphertext) {
				plaintext = make([]byte, len(ciphertext))
			}

			debug.Log("  ciphertext %d, plaintext %d", len(plaintext), len(ciphertext))

			n, err := crypto.Decrypt(repo.Key(), plaintext, ciphertext)
			if err != nil {
				return err
			}
			plaintext = plaintext[:n]

			_, err = repo.SaveBlob(entry.Type, plaintext, entry.ID)
			if err != nil {
				return err
			}

			debug.Log("  saved blob %v", entry.ID.Str())

			keepBlobs.Delete(h)
		}
	}

	if err := repo.Flush(); err != nil {
		return err
	}

	for packID := range packs {
		err := repo.Backend().Remove(restic.DataFile, packID.String())
		if err != nil {
			debug.Log("error removing pack %v: %v", packID.Str(), err)
			return err
		}
		debug.Log("removed pack %v", packID.Str())
	}

	return nil
}

func lockExists(repo restic.Repository, t testing.TB, id restic.ID) bool {
	exists, err := repo.Backend().Test(restic.LockFile, id.String())
	OK(t, err)

	return exists
}

func removeLock(repo restic.Repository, id restic.ID) error {
	return repo.Backend().Remove(restic.LockFile, id.String())
}