Merge pull request #3830 from MichaelEischer/cleanup-repo

Extract Load/SaveTree/JSONUnpacked from repository

cmd/restic/cmd_cat.go

@@ -79,7 +79,7 @@ func runCat(gopts GlobalOptions, args []string) error {
 		Println(string(buf))
 		return nil
 	case "index":
-		buf, err := repo.LoadUnpacked(gopts.ctx, nil, restic.IndexFile, id)
+		buf, err := repo.LoadUnpacked(gopts.ctx, restic.IndexFile, id, nil)
 		if err != nil {
 			return err
 		}
@@ -87,13 +87,12 @@ func runCat(gopts GlobalOptions, args []string) error {
 		Println(string(buf))
 		return nil
 	case "snapshot":
-		sn := &restic.Snapshot{}
+		sn, err := restic.LoadSnapshot(gopts.ctx, repo, id)
-		err = repo.LoadJSONUnpacked(gopts.ctx, restic.SnapshotFile, id, sn)
 		if err != nil {
 			return err
 		}
 
-		buf, err := json.MarshalIndent(&sn, "", "  ")
+		buf, err := json.MarshalIndent(sn, "", "  ")
 		if err != nil {
 			return err
 		}

cmd/restic/cmd_copy.go

@@ -154,7 +154,7 @@ func runCopy(opts CopyOptions, gopts GlobalOptions, args []string) error {
 		if sn.Original == nil {
 			sn.Original = sn.ID()
 		}
-		newID, err := dstRepo.SaveJSONUnpacked(ctx, restic.SnapshotFile, sn)
+		newID, err := restic.SaveSnapshot(ctx, dstRepo, sn)
 		if err != nil {
 			return err
 		}

cmd/restic/cmd_diff.go

@@ -160,7 +160,7 @@ func updateBlobs(repo restic.Repository, blobs restic.BlobSet, stats *DiffStat)
 
 func (c *Comparer) printDir(ctx context.Context, mode string, stats *DiffStat, blobs restic.BlobSet, prefix string, id restic.ID) error {
 	debug.Log("print %v tree %v", mode, id)
-	tree, err := c.repo.LoadTree(ctx, id)
+	tree, err := restic.LoadTree(ctx, c.repo, id)
 	if err != nil {
 		return err
 	}
@@ -187,7 +187,7 @@ func (c *Comparer) printDir(ctx context.Context, mode string, stats *DiffStat, b
 
 func (c *Comparer) collectDir(ctx context.Context, blobs restic.BlobSet, id restic.ID) error {
 	debug.Log("print tree %v", id)
-	tree, err := c.repo.LoadTree(ctx, id)
+	tree, err := restic.LoadTree(ctx, c.repo, id)
 	if err != nil {
 		return err
 	}
@@ -231,12 +231,12 @@ func uniqueNodeNames(tree1, tree2 *restic.Tree) (tree1Nodes, tree2Nodes map[stri
 
 func (c *Comparer) diffTree(ctx context.Context, stats *DiffStatsContainer, prefix string, id1, id2 restic.ID) error {
 	debug.Log("diffing %v to %v", id1, id2)
-	tree1, err := c.repo.LoadTree(ctx, id1)
+	tree1, err := restic.LoadTree(ctx, c.repo, id1)
 	if err != nil {
 		return err
 	}
 
-	tree2, err := c.repo.LoadTree(ctx, id2)
+	tree2, err := restic.LoadTree(ctx, c.repo, id2)
 	if err != nil {
 		return err
 	}

cmd/restic/cmd_dump.go

@@ -87,7 +87,7 @@ func printFromTree(ctx context.Context, tree *restic.Tree, repo restic.Repositor
 			case l == 1 && dump.IsFile(node):
 				return d.WriteNode(ctx, node)
 			case l > 1 && dump.IsDir(node):
-				subtree, err := repo.LoadTree(ctx, *node.Subtree)
+				subtree, err := restic.LoadTree(ctx, repo, *node.Subtree)
 				if err != nil {
 					return errors.Wrapf(err, "cannot load subtree for %q", item)
 				}
@@ -96,7 +96,7 @@ func printFromTree(ctx context.Context, tree *restic.Tree, repo restic.Repositor
 				if err := checkStdoutArchive(); err != nil {
 					return err
 				}
-				subtree, err := repo.LoadTree(ctx, *node.Subtree)
+				subtree, err := restic.LoadTree(ctx, repo, *node.Subtree)
 				if err != nil {
 					return err
 				}
@@ -168,7 +168,7 @@ func runDump(opts DumpOptions, gopts GlobalOptions, args []string) error {
 		return err
 	}
 
-	tree, err := repo.LoadTree(ctx, *sn.Tree)
+	tree, err := restic.LoadTree(ctx, repo, *sn.Tree)
 	if err != nil {
 		Exitf(2, "loading tree for snapshot %q failed: %v", snapshotIDString, err)
 	}

cmd/restic/cmd_recover.go

@@ -75,7 +75,7 @@ func runRecover(gopts GlobalOptions) error {
 	Verbosef("load %d trees\n", len(trees))
 	bar := newProgressMax(!gopts.Quiet, uint64(len(trees)), "trees loaded")
 	for id := range trees {
-		tree, err := repo.LoadTree(gopts.ctx, id)
+		tree, err := restic.LoadTree(gopts.ctx, repo, id)
 		if err != nil {
 			Warnf("unable to load tree %v: %v\n", id.Str(), err)
 			continue
@@ -138,7 +138,7 @@ func runRecover(gopts GlobalOptions) error {
 	var treeID restic.ID
 	wg.Go(func() error {
 		var err error
-		treeID, err = repo.SaveTree(ctx, tree)
+		treeID, err = restic.SaveTree(ctx, repo, tree)
 		if err != nil {
 			return errors.Fatalf("unable to save new tree to the repository: %v", err)
 		}
@@ -166,7 +166,7 @@ func createSnapshot(ctx context.Context, name, hostname string, tags []string, r
 
 	sn.Tree = tree
 
-	id, err := repo.SaveJSONUnpacked(ctx, restic.SnapshotFile, sn)
+	id, err := restic.SaveSnapshot(ctx, repo, sn)
 	if err != nil {
 		return errors.Fatalf("unable to save snapshot: %v", err)
 	}

cmd/restic/cmd_tag.go

@@ -82,7 +82,7 @@ func changeTags(ctx context.Context, repo *repository.Repository, sn *restic.Sna
 		}
 
 		// Save the new snapshot.
-		id, err := repo.SaveJSONUnpacked(ctx, restic.SnapshotFile, sn)
+		id, err := restic.SaveSnapshot(ctx, repo, sn)
 		if err != nil {
 			return false, err
 		}

cmd/restic/find.go

@@ -8,7 +8,7 @@ import (
 )
 
 // FindFilteredSnapshots yields Snapshots, either given explicitly by `snapshotIDs` or filtered from the list of all snapshots.
-func FindFilteredSnapshots(ctx context.Context, be restic.Lister, loader restic.LoadJSONUnpackeder, hosts []string, tags []restic.TagList, paths []string, snapshotIDs []string) <-chan *restic.Snapshot {
+func FindFilteredSnapshots(ctx context.Context, be restic.Lister, loader restic.LoaderUnpacked, hosts []string, tags []restic.TagList, paths []string, snapshotIDs []string) <-chan *restic.Snapshot {
 	out := make(chan *restic.Snapshot)
 	go func() {
 		defer close(out)

internal/archiver/archiver.go

@@ -218,7 +218,7 @@ func (arch *Archiver) loadSubtree(ctx context.Context, node *restic.Node) (*rest
 		return nil, nil
 	}
 
-	tree, err := arch.Repo.LoadTree(ctx, *node.Subtree)
+	tree, err := restic.LoadTree(ctx, arch.Repo, *node.Subtree)
 	if err != nil {
 		debug.Log("unable to load tree %v: %v", node.Subtree.Str(), err)
 		// a tree in the repository is not readable -> warn the user
@@ -762,7 +762,7 @@ func (arch *Archiver) loadParentTree(ctx context.Context, snapshotID restic.ID)
 	}
 
 	debug.Log("load parent tree %v", *sn.Tree)
-	tree, err := arch.Repo.LoadTree(ctx, *sn.Tree)
+	tree, err := restic.LoadTree(ctx, arch.Repo, *sn.Tree)
 	if err != nil {
 		debug.Log("unable to load tree %v: %v", *sn.Tree, err)
 		_ = arch.error("/", nil, arch.wrapLoadTreeError(*sn.Tree, err))
@@ -863,7 +863,7 @@ func (arch *Archiver) Snapshot(ctx context.Context, targets []string, opts Snaps
 	}
 	sn.Tree = &rootTreeID
 
-	id, err := arch.Repo.SaveJSONUnpacked(ctx, restic.SnapshotFile, sn)
+	id, err := restic.SaveSnapshot(ctx, arch.Repo, sn)
 	if err != nil {
 		return nil, restic.ID{}, err
 	}

internal/archiver/archiver_test.go

@@ -431,7 +431,7 @@ func (repo *blobCountingRepo) SaveBlob(ctx context.Context, t restic.BlobType, b
 }
 
 func (repo *blobCountingRepo) SaveTree(ctx context.Context, t *restic.Tree) (restic.ID, error) {
-	id, err := repo.Repository.SaveTree(ctx, t)
+	id, err := restic.SaveTree(ctx, repo.Repository, t)
 	h := restic.BlobHandle{ID: id, Type: restic.TreeBlob}
 	repo.m.Lock()
 	repo.saved[h]++
@@ -875,7 +875,7 @@ func TestArchiverSaveDir(t *testing.T) {
 
 			node.Name = targetNodeName
 			tree := &restic.Tree{Nodes: []*restic.Node{node}}
-			treeID, err := repo.SaveTree(ctx, tree)
+			treeID, err := restic.SaveTree(ctx, repo, tree)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -1123,7 +1123,7 @@ func TestArchiverSaveTree(t *testing.T) {
 				t.Fatal(err)
 			}
 
-			treeID, err := repo.SaveTree(ctx, tree)
+			treeID, err := restic.SaveTree(ctx, repo, tree)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -2076,7 +2076,7 @@ func snapshot(t testing.TB, repo restic.Repository, fs fs.FS, parent restic.ID,
 		t.Fatal(err)
 	}
 
-	tree, err := repo.LoadTree(ctx, *snapshot.Tree)
+	tree, err := restic.LoadTree(ctx, repo, *snapshot.Tree)
 	if err != nil {
 		t.Fatal(err)
 	}

internal/archiver/testing.go

@@ -251,7 +251,7 @@ func TestEnsureFileContent(ctx context.Context, t testing.TB, repo restic.Reposi
 func TestEnsureTree(ctx context.Context, t testing.TB, prefix string, repo restic.Repository, treeID restic.ID, dir TestDir) {
 	t.Helper()
 
-	tree, err := repo.LoadTree(ctx, treeID)
+	tree, err := restic.LoadTree(ctx, repo, treeID)
 	if err != nil {
 		t.Fatal(err)
 		return

internal/checker/checker_test.go

@@ -403,7 +403,7 @@ func (r *loadTreesOnceRepository) LoadTree(ctx context.Context, id restic.ID) (*
 		return nil, errors.Errorf("trying to load tree with id %v twice", id)
 	}
 	r.loadedTrees.Insert(id)
-	return r.Repository.LoadTree(ctx, id)
+	return restic.LoadTree(ctx, r.Repository, id)
 }
 
 func TestCheckerNoDuplicateTreeDecodes(t *testing.T) {
@@ -443,7 +443,7 @@ func (r *delayRepository) LoadTree(ctx context.Context, id restic.ID) (*restic.T
 	if id == r.DelayTree {
 		<-r.UnblockChannel
 	}
-	return r.Repository.LoadTree(ctx, id)
+	return restic.LoadTree(ctx, r.Repository, id)
 }
 
 func (r *delayRepository) LookupBlobSize(id restic.ID, t restic.BlobType) (uint, bool) {
@@ -479,7 +479,7 @@ func TestCheckerBlobTypeConfusion(t *testing.T) {
 
 	wg, wgCtx := errgroup.WithContext(ctx)
 	repo.StartPackUploader(wgCtx, wg)
-	id, err := repo.SaveTree(ctx, damagedTree)
+	id, err := restic.SaveTree(ctx, repo, damagedTree)
 	test.OK(t, repo.Flush(ctx))
 	test.OK(t, err)
 
@@ -509,7 +509,7 @@ func TestCheckerBlobTypeConfusion(t *testing.T) {
 		Nodes: []*restic.Node{malNode, dirNode},
 	}
 
-	rootID, err := repo.SaveTree(ctx, rootTree)
+	rootID, err := restic.SaveTree(ctx, repo, rootTree)
 	test.OK(t, err)
 
 	test.OK(t, repo.Flush(ctx))
@@ -519,7 +519,7 @@ func TestCheckerBlobTypeConfusion(t *testing.T) {
 
 	snapshot.Tree = &rootID
 
-	snapID, err := repo.SaveJSONUnpacked(ctx, restic.SnapshotFile, snapshot)
+	snapID, err := restic.SaveSnapshot(ctx, repo, snapshot)
 	test.OK(t, err)
 
 	t.Logf("saved snapshot %v", snapID.Str())
@@ -600,8 +600,7 @@ func benchmarkSnapshotScaling(t *testing.B, newSnapshots int) {
 		t.Fatal(err)
 	}
 
-	var sn2 restic.Snapshot
+	sn2, err := restic.LoadSnapshot(context.TODO(), repo, snID)
-	err = repo.LoadJSONUnpacked(context.TODO(), restic.SnapshotFile, snID, &sn2)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -615,7 +614,7 @@ func benchmarkSnapshotScaling(t *testing.B, newSnapshots int) {
 		}
 		sn.Tree = treeID
 
-		_, err = repo.SaveJSONUnpacked(context.TODO(), restic.SnapshotFile, sn)
+		_, err = restic.SaveSnapshot(context.TODO(), repo, sn)
 		if err != nil {
 			t.Fatal(err)
 		}

internal/dump/common_test.go

@@ -88,7 +88,7 @@ func WriteTest(t *testing.T, format string, cd CheckDump) {
 			sn, _, err := arch.Snapshot(ctx, []string{"."}, archiver.SnapshotOptions{})
 			rtest.OK(t, err)
 
-			tree, err := repo.LoadTree(ctx, *sn.Tree)
+			tree, err := restic.LoadTree(ctx, repo, *sn.Tree)
 			rtest.OK(t, err)
 
 			dst := &bytes.Buffer{}

internal/fuse/dir.go

@@ -55,7 +55,7 @@ func replaceSpecialNodes(ctx context.Context, repo restic.Repository, node *rest
 		return []*restic.Node{node}, nil
 	}
 
-	tree, err := repo.LoadTree(ctx, *node.Subtree)
+	tree, err := restic.LoadTree(ctx, repo, *node.Subtree)
 	if err != nil {
 		return nil, err
 	}
@@ -88,7 +88,7 @@ func (d *dir) open(ctx context.Context) error {
 
 	debug.Log("open dir %v (%v)", d.node.Name, d.node.Subtree)
 
-	tree, err := d.root.repo.LoadTree(ctx, *d.node.Subtree)
+	tree, err := restic.LoadTree(ctx, d.root.repo, *d.node.Subtree)
 	if err != nil {
 		debug.Log("  error loading tree %v: %v", d.node.Subtree, err)
 		return err

internal/fuse/fuse_test.go

@@ -59,7 +59,7 @@ func loadFirstSnapshot(t testing.TB, repo restic.Repository) *restic.Snapshot {
 }
 
 func loadTree(t testing.TB, repo restic.Repository, id restic.ID) *restic.Tree {
-	tree, err := repo.LoadTree(context.TODO(), id)
+	tree, err := restic.LoadTree(context.TODO(), repo, id)
 	rtest.OK(t, err)
 	return tree
 }

internal/migrations/upgrade_repo_v2.go

@@ -68,7 +68,7 @@ func (*UpgradeRepoV2) upgrade(ctx context.Context, repo restic.Repository) error
 	cfg := repo.Config()
 	cfg.Version = 2
 
-	_, err := repo.SaveJSONUnpacked(ctx, restic.ConfigFile, cfg)
+	err := restic.SaveConfig(ctx, repo, cfg)
 	if err != nil {
 		return fmt.Errorf("save new config file failed: %w", err)
 	}

internal/repository/index_parallel.go

@@ -52,7 +52,7 @@ func ForAllIndexes(ctx context.Context, repo restic.Repository,
 			var idx *Index
 			oldFormat := false
 
-			buf, err = repo.LoadUnpacked(ctx, buf[:0], restic.IndexFile, fi.ID)
+			buf, err = repo.LoadUnpacked(ctx, restic.IndexFile, fi.ID, buf[:0])
 			if err == nil {
 				idx, oldFormat, err = DecodeIndex(buf, fi.ID)
 			}

internal/repository/repository.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"bytes"
 	"context"
-	"encoding/json"
 	"fmt"
 	"io"
 	"os"
@@ -154,7 +153,7 @@ func (r *Repository) PrefixLength(ctx context.Context, t restic.FileType) (int,
 // LoadUnpacked loads and decrypts the file with the given type and ID, using
 // the supplied buffer (which must be empty). If the buffer is nil, a new
 // buffer will be allocated and returned.
-func (r *Repository) LoadUnpacked(ctx context.Context, buf []byte, t restic.FileType, id restic.ID) ([]byte, error) {
+func (r *Repository) LoadUnpacked(ctx context.Context, t restic.FileType, id restic.ID, buf []byte) ([]byte, error) {
 	if len(buf) != 0 {
 		panic("buf is not empty")
 	}
@@ -316,17 +315,6 @@ func (r *Repository) LoadBlob(ctx context.Context, t restic.BlobType, id restic.
 	return nil, errors.Errorf("loading blob %v from %v packs failed", id.Str(), len(blobs))
 }
 
-// LoadJSONUnpacked decrypts the data and afterwards calls json.Unmarshal on
-// the item.
-func (r *Repository) LoadJSONUnpacked(ctx context.Context, t restic.FileType, id restic.ID, item interface{}) (err error) {
-	buf, err := r.LoadUnpacked(ctx, nil, t, id)
-	if err != nil {
-		return err
-	}
-
-	return json.Unmarshal(buf, item)
-}
-
 // LookupBlobSize returns the size of blob id.
 func (r *Repository) LookupBlobSize(id restic.ID, tpe restic.BlobType) (uint, bool) {
 	return r.idx.LookupSize(restic.BlobHandle{ID: id, Type: tpe})
@@ -420,18 +408,6 @@ func (r *Repository) saveAndEncrypt(ctx context.Context, t restic.BlobType, data
 	return pm.SaveBlob(ctx, t, id, ciphertext, uncompressedLength)
 }
 
-// SaveJSONUnpacked serialises item as JSON and encrypts and saves it in the
-// backend as type t, without a pack. It returns the storage hash.
-func (r *Repository) SaveJSONUnpacked(ctx context.Context, t restic.FileType, item interface{}) (restic.ID, error) {
-	debug.Log("save new blob %v", t)
-	plaintext, err := json.Marshal(item)
-	if err != nil {
-		return restic.ID{}, errors.Wrap(err, "json.Marshal")
-	}
-
-	return r.SaveUnpacked(ctx, t, plaintext)
-}
-
 func (r *Repository) compressUnpacked(p []byte) ([]byte, error) {
 	// compression is only available starting from version 2
 	if r.cfg.Version < 2 {
@@ -763,8 +739,7 @@ func (r *Repository) init(ctx context.Context, password string, cfg restic.Confi
 	r.key = key.master
 	r.keyName = key.Name()
 	r.setConfig(cfg)
-	_, err = r.SaveJSONUnpacked(ctx, restic.ConfigFile, cfg)
+	return restic.SaveConfig(ctx, r, cfg)
-	return err
 }
 
 // Key returns the current master key.
@@ -835,41 +810,6 @@ func (r *Repository) SaveBlob(ctx context.Context, t restic.BlobType, buf []byte
 	return newID, known, size, err
 }
 
-// LoadTree loads a tree from the repository.
-func (r *Repository) LoadTree(ctx context.Context, id restic.ID) (*restic.Tree, error) {
-	debug.Log("load tree %v", id)
-
-	buf, err := r.LoadBlob(ctx, restic.TreeBlob, id, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	t := &restic.Tree{}
-	err = json.Unmarshal(buf, t)
-	if err != nil {
-		return nil, err
-	}
-
-	return t, nil
-}
-
-// SaveTree stores a tree into the repository and returns the ID. The ID is
-// checked against the index. The tree is only stored when the index does not
-// contain the ID.
-func (r *Repository) SaveTree(ctx context.Context, t *restic.Tree) (restic.ID, error) {
-	buf, err := json.Marshal(t)
-	if err != nil {
-		return restic.ID{}, errors.Wrap(err, "MarshalJSON")
-	}
-
-	// append a newline so that the data is always consistent (json.Encoder
-	// adds a newline after each object)
-	buf = append(buf, '\n')
-
-	id, _, _, err := r.SaveBlob(ctx, restic.TreeBlob, buf, restic.ID{}, false)
-	return id, err
-}
-
 type BackendLoadFn func(ctx context.Context, h restic.Handle, length int, offset int64, fn func(rd io.Reader) error) error
 
 // StreamPack loads the listed blobs from the specified pack file. The plaintext blob is passed to

internal/repository/repository_test.go

@@ -16,7 +16,6 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/klauspost/compress/zstd"
-	"github.com/restic/restic/internal/archiver"
 	"github.com/restic/restic/internal/crypto"
 	"github.com/restic/restic/internal/repository"
 	"github.com/restic/restic/internal/restic"
@@ -137,50 +136,6 @@ func benchmarkSaveAndEncrypt(t *testing.B, version uint) {
 	}
 }
 
-func TestLoadTree(t *testing.T) {
-	repository.TestAllVersions(t, testLoadTree)
-}
-
-func testLoadTree(t *testing.T, version uint) {
-	repo, cleanup := repository.TestRepositoryWithVersion(t, version)
-	defer cleanup()
-
-	if rtest.BenchArchiveDirectory == "" {
-		t.Skip("benchdir not set, skipping")
-	}
-
-	// archive a few files
-	sn := archiver.TestSnapshot(t, repo, rtest.BenchArchiveDirectory, nil)
-	rtest.OK(t, repo.Flush(context.Background()))
-
-	_, err := repo.LoadTree(context.TODO(), *sn.Tree)
-	rtest.OK(t, err)
-}
-
-func BenchmarkLoadTree(t *testing.B) {
-	repository.BenchmarkAllVersions(t, benchmarkLoadTree)
-}
-
-func benchmarkLoadTree(t *testing.B, version uint) {
-	repo, cleanup := repository.TestRepositoryWithVersion(t, version)
-	defer cleanup()
-
-	if rtest.BenchArchiveDirectory == "" {
-		t.Skip("benchdir not set, skipping")
-	}
-
-	// archive a few files
-	sn := archiver.TestSnapshot(t, repo, rtest.BenchArchiveDirectory, nil)
-	rtest.OK(t, repo.Flush(context.Background()))
-
-	t.ResetTimer()
-
-	for i := 0; i < t.N; i++ {
-		_, err := repo.LoadTree(context.TODO(), *sn.Tree)
-		rtest.OK(t, err)
-	}
-}
-
 func TestLoadBlob(t *testing.T) {
 	repository.TestAllVersions(t, testLoadBlob)
 }
@@ -283,7 +238,7 @@ func benchmarkLoadUnpacked(b *testing.B, version uint) {
 	b.SetBytes(int64(length))
 
 	for i := 0; i < b.N; i++ {
-		data, err := repo.LoadUnpacked(context.TODO(), nil, restic.PackFile, storageID)
+		data, err := repo.LoadUnpacked(context.TODO(), restic.PackFile, storageID, nil)
 		rtest.OK(b, err)
 
 		// See comment in BenchmarkLoadBlob.
@@ -300,44 +255,6 @@ func benchmarkLoadUnpacked(b *testing.B, version uint) {
 	}
 }
 
-func TestLoadJSONUnpacked(t *testing.T) {
-	repository.TestAllVersions(t, testLoadJSONUnpacked)
-}
-
-func testLoadJSONUnpacked(t *testing.T, version uint) {
-	repo, cleanup := repository.TestRepositoryWithVersion(t, version)
-	defer cleanup()
-
-	if rtest.BenchArchiveDirectory == "" {
-		t.Skip("benchdir not set, skipping")
-	}
-
-	// archive a snapshot
-	sn := restic.Snapshot{}
-	sn.Hostname = "foobar"
-	sn.Username = "test!"
-
-	id, err := repo.SaveJSONUnpacked(context.TODO(), restic.SnapshotFile, &sn)
-	rtest.OK(t, err)
-
-	var sn2 restic.Snapshot
-
-	// restore
-	err = repo.LoadJSONUnpacked(context.TODO(), restic.SnapshotFile, id, &sn2)
-	rtest.OK(t, err)
-
-	rtest.Equals(t, sn.Hostname, sn2.Hostname)
-	rtest.Equals(t, sn.Username, sn2.Username)
-
-	var cf restic.Config
-
-	// load and check Config
-	err = repo.LoadJSONUnpacked(context.TODO(), restic.ConfigFile, id, &cf)
-	rtest.OK(t, err)
-
-	rtest.Equals(t, cf.ChunkerPolynomial, repository.TestChunkerPol)
-}
-
 var repoFixture = filepath.Join("testdata", "test-repo.tar.gz")
 
 func TestRepositoryLoadIndex(t *testing.T) {
@@ -350,7 +267,7 @@ func TestRepositoryLoadIndex(t *testing.T) {
 
 // loadIndex loads the index id from backend and returns it.
 func loadIndex(ctx context.Context, repo restic.Repository, id restic.ID) (*repository.Index, error) {
-	buf, err := repo.LoadUnpacked(ctx, nil, restic.IndexFile, id)
+	buf, err := repo.LoadUnpacked(ctx, restic.IndexFile, id, nil)
 	if err != nil {
 		return nil, err
 	}

internal/restic/config.go

@@ -76,12 +76,12 @@ func TestDisableCheckPolynomial(t testing.TB) {
 }
 
 // LoadConfig returns loads, checks and returns the config for a repository.
-func LoadConfig(ctx context.Context, r JSONUnpackedLoader) (Config, error) {
+func LoadConfig(ctx context.Context, r LoaderUnpacked) (Config, error) {
 	var (
 		cfg Config
 	)
 
-	err := r.LoadJSONUnpacked(ctx, ConfigFile, ID{}, &cfg)
+	err := LoadJSONUnpacked(ctx, r, ConfigFile, ID{}, &cfg)
 	if err != nil {
 		return Config{}, err
 	}
@@ -98,3 +98,8 @@ func LoadConfig(ctx context.Context, r JSONUnpackedLoader) (Config, error) {
 
 	return cfg, nil
 }
+
+func SaveConfig(ctx context.Context, r SaverUnpacked, cfg Config) error {
+	_, err := SaveJSONUnpacked(ctx, r, ConfigFile, cfg)
+	return err
+}

internal/restic/config_test.go

@@ -8,47 +8,56 @@ import (
 	rtest "github.com/restic/restic/internal/test"
 )
 
-type saver func(restic.FileType, interface{}) (restic.ID, error)
+type saver struct {
-
+	fn func(restic.FileType, []byte) (restic.ID, error)
-func (s saver) SaveJSONUnpacked(t restic.FileType, arg interface{}) (restic.ID, error) {
-	return s(t, arg)
 }
 
-type loader func(context.Context, restic.FileType, restic.ID, interface{}) error
+func (s saver) SaveUnpacked(ctx context.Context, t restic.FileType, buf []byte) (restic.ID, error) {
+	return s.fn(t, buf)
+}
 
-func (l loader) LoadJSONUnpacked(ctx context.Context, t restic.FileType, id restic.ID, arg interface{}) error {
+func (s saver) Connections() uint {
-	return l(ctx, t, id, arg)
+	return 2
+}
+
+type loader struct {
+	fn func(restic.FileType, restic.ID, []byte) ([]byte, error)
+}
+
+func (l loader) LoadUnpacked(ctx context.Context, t restic.FileType, id restic.ID, buf []byte) (data []byte, err error) {
+	return l.fn(t, id, buf)
+}
+
+func (l loader) Connections() uint {
+	return 2
 }
 
 func TestConfig(t *testing.T) {
-	resultConfig := restic.Config{}
+	var resultBuf []byte
-	save := func(tpe restic.FileType, arg interface{}) (restic.ID, error) {
+	save := func(tpe restic.FileType, buf []byte) (restic.ID, error) {
 		rtest.Assert(t, tpe == restic.ConfigFile,
 			"wrong backend type: got %v, wanted %v",
 			tpe, restic.ConfigFile)
 
-		cfg := arg.(restic.Config)
+		resultBuf = buf
-		resultConfig = cfg
 		return restic.ID{}, nil
 	}
 
 	cfg1, err := restic.CreateConfig(restic.MaxRepoVersion)
 	rtest.OK(t, err)
 
-	_, err = saver(save).SaveJSONUnpacked(restic.ConfigFile, cfg1)
+	err = restic.SaveConfig(context.TODO(), saver{save}, cfg1)
 	rtest.OK(t, err)
 
-	load := func(ctx context.Context, tpe restic.FileType, id restic.ID, arg interface{}) error {
+	load := func(tpe restic.FileType, id restic.ID, in []byte) ([]byte, error) {
 		rtest.Assert(t, tpe == restic.ConfigFile,
 			"wrong backend type: got %v, wanted %v",
 			tpe, restic.ConfigFile)
 
-		cfg := arg.(*restic.Config)
+		return resultBuf, nil
-		*cfg = resultConfig
-		return nil
 	}
 
-	cfg2, err := restic.LoadConfig(context.TODO(), loader(load))
+	cfg2, err := restic.LoadConfig(context.TODO(), loader{load})
 	rtest.OK(t, err)
 
 	rtest.Assert(t, cfg1 == cfg2,

internal/restic/find.go

@@ -8,16 +8,16 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
-// TreeLoader loads a tree from a repository.
+// Loader loads a blob from a repository.
-type TreeLoader interface {
+type Loader interface {
-	LoadTree(context.Context, ID) (*Tree, error)
+	LoadBlob(context.Context, BlobType, ID, []byte) ([]byte, error)
 	LookupBlobSize(id ID, tpe BlobType) (uint, bool)
 	Connections() uint
 }
 
 // FindUsedBlobs traverses the tree ID and adds all seen blobs (trees and data
 // blobs) to the set blobs. Already seen tree blobs will not be visited again.
-func FindUsedBlobs(ctx context.Context, repo TreeLoader, treeIDs IDs, blobs BlobSet, p *progress.Counter) error {
+func FindUsedBlobs(ctx context.Context, repo Loader, treeIDs IDs, blobs BlobSet, p *progress.Counter) error {
 	var lock sync.Mutex
 
 	wg, ctx := errgroup.WithContext(ctx)

internal/restic/find_test.go

@@ -162,7 +162,7 @@ func TestMultiFindUsedBlobs(t *testing.T) {
 
 type ForbiddenRepo struct{}
 
-func (r ForbiddenRepo) LoadTree(ctx context.Context, id restic.ID) (*restic.Tree, error) {
+func (r ForbiddenRepo) LoadBlob(context.Context, restic.BlobType, restic.ID, []byte) ([]byte, error) {
 	return nil, errors.New("should not be called")
 }
 

internal/restic/json.go

@@ -0,0 +1,32 @@
+package restic
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/restic/restic/internal/debug"
+	"github.com/restic/restic/internal/errors"
+)
+
+// LoadJSONUnpacked decrypts the data and afterwards calls json.Unmarshal on
+// the item.
+func LoadJSONUnpacked(ctx context.Context, repo LoaderUnpacked, t FileType, id ID, item interface{}) (err error) {
+	buf, err := repo.LoadUnpacked(ctx, t, id, nil)
+	if err != nil {
+		return err
+	}
+
+	return json.Unmarshal(buf, item)
+}
+
+// SaveJSONUnpacked serialises item as JSON and encrypts and saves it in the
+// backend as type t, without a pack. It returns the storage hash.
+func SaveJSONUnpacked(ctx context.Context, repo SaverUnpacked, t FileType, item interface{}) (ID, error) {
+	debug.Log("save new blob %v", t)
+	plaintext, err := json.Marshal(item)
+	if err != nil {
+		return ID{}, errors.Wrap(err, "json.Marshal")
+	}
+
+	return repo.SaveUnpacked(ctx, t, plaintext)
+}

internal/restic/lock.go

@@ -158,7 +158,7 @@ func (l *Lock) checkForOtherLocks(ctx context.Context) error {
 
 // createLock acquires the lock by creating a file in the repository.
 func (l *Lock) createLock(ctx context.Context) (ID, error) {
-	id, err := l.repo.SaveJSONUnpacked(ctx, LockFile, l)
+	id, err := SaveJSONUnpacked(ctx, l.repo, LockFile, l)
 	if err != nil {
 		return ID{}, err
 	}
@@ -255,7 +255,7 @@ func init() {
 // LoadLock loads and unserializes a lock from a repository.
 func LoadLock(ctx context.Context, repo Repository, id ID) (*Lock, error) {
 	lock := &Lock{}
-	if err := repo.LoadJSONUnpacked(ctx, LockFile, id, lock); err != nil {
+	if err := LoadJSONUnpacked(ctx, repo, LockFile, id, lock); err != nil {
 		return nil, err
 	}
 	lock.lockID = &id

internal/restic/lock_test.go

@@ -99,7 +99,7 @@ func createFakeLock(repo restic.Repository, t time.Time, pid int) (restic.ID, er
 	}
 
 	newLock := &restic.Lock{Time: t, PID: pid, Hostname: hostname}
-	return repo.SaveJSONUnpacked(context.TODO(), restic.LockFile, &newLock)
+	return restic.SaveJSONUnpacked(context.TODO(), repo, restic.LockFile, &newLock)
 }
 
 func removeLock(repo restic.Repository, id restic.ID) error {

internal/restic/repository.go

@@ -37,26 +37,20 @@ type Repository interface {
 	// the the pack header.
 	ListPack(context.Context, ID, int64) ([]Blob, uint32, error)
 
+	LoadBlob(context.Context, BlobType, ID, []byte) ([]byte, error)
+	SaveBlob(context.Context, BlobType, []byte, ID, bool) (ID, bool, int, error)
+
 	// StartPackUploader start goroutines to upload new pack files. The errgroup
 	// is used to immediately notify about an upload error. Flush() will also return
 	// that error.
 	StartPackUploader(ctx context.Context, wg *errgroup.Group)
 	Flush(context.Context) error
 
-	SaveUnpacked(context.Context, FileType, []byte) (ID, error)
-	SaveJSONUnpacked(context.Context, FileType, interface{}) (ID, error)
-
-	LoadJSONUnpacked(ctx context.Context, t FileType, id ID, dest interface{}) error
 	// LoadUnpacked loads and decrypts the file with the given type and ID,
 	// using the supplied buffer (which must be empty). If the buffer is nil, a
 	// new buffer will be allocated and returned.
-	LoadUnpacked(ctx context.Context, buf []byte, t FileType, id ID) (data []byte, err error)
+	LoadUnpacked(ctx context.Context, t FileType, id ID, buf []byte) (data []byte, err error)
-
+	SaveUnpacked(context.Context, FileType, []byte) (ID, error)
-	LoadBlob(context.Context, BlobType, ID, []byte) ([]byte, error)
-	SaveBlob(context.Context, BlobType, []byte, ID, bool) (ID, bool, int, error)
-
-	LoadTree(context.Context, ID) (*Tree, error)
-	SaveTree(context.Context, *Tree) (ID, error)
 }
 
 // Lister allows listing files in a backend.
@@ -64,11 +58,11 @@ type Lister interface {
 	List(context.Context, FileType, func(FileInfo) error) error
 }
 
-// LoadJSONUnpackeder allows loading a JSON file not stored in a pack file
+// LoaderUnpacked allows loading a blob not stored in a pack file
-type LoadJSONUnpackeder interface {
+type LoaderUnpacked interface {
 	// Connections returns the maximum number of concurrent backend operations
 	Connections() uint
-	LoadJSONUnpacked(ctx context.Context, t FileType, id ID, dest interface{}) error
+	LoadUnpacked(ctx context.Context, t FileType, id ID, buf []byte) (data []byte, err error)
 }
 
 // SaverUnpacked allows saving a blob not stored in a pack file

internal/restic/snapshot.go

@@ -59,9 +59,9 @@ func NewSnapshot(paths []string, tags []string, hostname string, time time.Time)
 }
 
 // LoadSnapshot loads the snapshot with the id and returns it.
-func LoadSnapshot(ctx context.Context, loader LoadJSONUnpackeder, id ID) (*Snapshot, error) {
+func LoadSnapshot(ctx context.Context, loader LoaderUnpacked, id ID) (*Snapshot, error) {
 	sn := &Snapshot{id: &id}
-	err := loader.LoadJSONUnpacked(ctx, SnapshotFile, id, sn)
+	err := LoadJSONUnpacked(ctx, loader, SnapshotFile, id, sn)
 	if err != nil {
 		return nil, err
 	}
@@ -69,12 +69,17 @@ func LoadSnapshot(ctx context.Context, loader LoadJSONUnpackeder, id ID) (*Snaps
 	return sn, nil
 }
 
+// SaveSnapshot saves the snapshot sn and returns its ID.
+func SaveSnapshot(ctx context.Context, repo SaverUnpacked, sn *Snapshot) (ID, error) {
+	return SaveJSONUnpacked(ctx, repo, SnapshotFile, sn)
+}
+
 // ForAllSnapshots reads all snapshots in parallel and calls the
 // given function. It is guaranteed that the function is not run concurrently.
 // If the called function returns an error, this function is cancelled and
 // also returns this error.
 // If a snapshot ID is in excludeIDs, it will be ignored.
-func ForAllSnapshots(ctx context.Context, be Lister, loader LoadJSONUnpackeder, excludeIDs IDSet, fn func(ID, *Snapshot, error) error) error {
+func ForAllSnapshots(ctx context.Context, be Lister, loader LoaderUnpacked, excludeIDs IDSet, fn func(ID, *Snapshot, error) error) error {
 	var m sync.Mutex
 
 	// track spawned goroutines using wg, create a new context which is

internal/restic/snapshot_find.go

@@ -14,7 +14,7 @@ import (
 var ErrNoSnapshotFound = errors.New("no snapshot found")
 
 // FindLatestSnapshot finds latest snapshot with optional target/directory, tags, hostname, and timestamp filters.
-func FindLatestSnapshot(ctx context.Context, be Lister, loader LoadJSONUnpackeder, targets []string,
+func FindLatestSnapshot(ctx context.Context, be Lister, loader LoaderUnpacked, targets []string,
 	tagLists []TagList, hostnames []string, timeStampLimit *time.Time) (ID, error) {
 
 	var err error
@@ -92,7 +92,7 @@ func FindSnapshot(ctx context.Context, be Lister, s string) (ID, error) {
 
 // FindFilteredSnapshots yields Snapshots filtered from the list of all
 // snapshots.
-func FindFilteredSnapshots(ctx context.Context, be Lister, loader LoadJSONUnpackeder, hosts []string, tags []TagList, paths []string) (Snapshots, error) {
+func FindFilteredSnapshots(ctx context.Context, be Lister, loader LoaderUnpacked, hosts []string, tags []TagList, paths []string) (Snapshots, error) {
 	results := make(Snapshots, 0, 20)
 
 	err := ForAllSnapshots(ctx, be, loader, nil, func(id ID, sn *Snapshot, err error) error {

internal/restic/snapshot_test.go

@@ -1,9 +1,11 @@
 package restic_test
 
 import (
+	"context"
 	"testing"
 	"time"
 
+	"github.com/restic/restic/internal/repository"
 	"github.com/restic/restic/internal/restic"
 	rtest "github.com/restic/restic/internal/test"
 )
@@ -24,3 +26,27 @@ func TestTagList(t *testing.T) {
 	r := sn.HasTags(tags)
 	rtest.Assert(t, r, "Failed to match untagged snapshot")
 }
+
+func TestLoadJSONUnpacked(t *testing.T) {
+	repository.TestAllVersions(t, testLoadJSONUnpacked)
+}
+
+func testLoadJSONUnpacked(t *testing.T, version uint) {
+	repo, cleanup := repository.TestRepositoryWithVersion(t, version)
+	defer cleanup()
+
+	// archive a snapshot
+	sn := restic.Snapshot{}
+	sn.Hostname = "foobar"
+	sn.Username = "test!"
+
+	id, err := restic.SaveSnapshot(context.TODO(), repo, &sn)
+	rtest.OK(t, err)
+
+	// restore
+	sn2, err := restic.LoadSnapshot(context.TODO(), repo, id)
+	rtest.OK(t, err)
+
+	rtest.Equals(t, sn.Hostname, sn2.Hostname)
+	rtest.Equals(t, sn.Username, sn2.Username)
+}

internal/restic/testing.go

@@ -181,7 +181,7 @@ func TestCreateSnapshot(t testing.TB, repo Repository, at time.Time, depth int,
 		t.Fatal(err)
 	}
 
-	id, err := repo.SaveJSONUnpacked(context.TODO(), SnapshotFile, snapshot)
+	id, err := SaveSnapshot(context.TODO(), repo, snapshot)
 	if err != nil {
 		t.Fatal(err)
 	}

internal/restic/tree.go

@@ -1,6 +1,8 @@
 package restic
 
 import (
+	"context"
+	"encoding/json"
 	"fmt"
 	"sort"
 
@@ -98,3 +100,46 @@ func (t *Tree) Subtrees() (trees IDs) {
 
 	return trees
 }
+
+type BlobLoader interface {
+	LoadBlob(context.Context, BlobType, ID, []byte) ([]byte, error)
+}
+
+// LoadTree loads a tree from the repository.
+func LoadTree(ctx context.Context, r BlobLoader, id ID) (*Tree, error) {
+	debug.Log("load tree %v", id)
+
+	buf, err := r.LoadBlob(ctx, TreeBlob, id, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	t := &Tree{}
+	err = json.Unmarshal(buf, t)
+	if err != nil {
+		return nil, err
+	}
+
+	return t, nil
+}
+
+type BlobSaver interface {
+	SaveBlob(context.Context, BlobType, []byte, ID, bool) (ID, bool, int, error)
+}
+
+// SaveTree stores a tree into the repository and returns the ID. The ID is
+// checked against the index. The tree is only stored when the index does not
+// contain the ID.
+func SaveTree(ctx context.Context, r BlobSaver, t *Tree) (ID, error) {
+	buf, err := json.Marshal(t)
+	if err != nil {
+		return ID{}, errors.Wrap(err, "MarshalJSON")
+	}
+
+	// append a newline so that the data is always consistent (json.Encoder
+	// adds a newline after each object)
+	buf = append(buf, '\n')
+
+	id, _, _, err := r.SaveBlob(ctx, TreeBlob, buf, ID{}, false)
+	return id, err
+}

internal/restic/tree_stream.go

@@ -29,11 +29,11 @@ type trackedID struct {
 }
 
 // loadTreeWorker loads trees from repo and sends them to out.
-func loadTreeWorker(ctx context.Context, repo TreeLoader,
+func loadTreeWorker(ctx context.Context, repo Loader,
 	in <-chan trackedID, out chan<- trackedTreeItem) {
 
 	for treeID := range in {
-		tree, err := repo.LoadTree(ctx, treeID.ID)
+		tree, err := LoadTree(ctx, repo, treeID.ID)
 		debug.Log("load tree %v (%v) returned err: %v", tree, treeID, err)
 		job := trackedTreeItem{TreeItem: TreeItem{ID: treeID.ID, Error: err, Tree: tree}, rootIdx: treeID.rootIdx}
 
@@ -45,7 +45,7 @@ func loadTreeWorker(ctx context.Context, repo TreeLoader,
 	}
 }
 
-func filterTrees(ctx context.Context, repo TreeLoader, trees IDs, loaderChan chan<- trackedID, hugeTreeLoaderChan chan<- trackedID,
+func filterTrees(ctx context.Context, repo Loader, trees IDs, loaderChan chan<- trackedID, hugeTreeLoaderChan chan<- trackedID,
 	in <-chan trackedTreeItem, out chan<- TreeItem, skip func(tree ID) bool, p *progress.Counter) {
 
 	var (
@@ -154,7 +154,7 @@ func filterTrees(ctx context.Context, repo TreeLoader, trees IDs, loaderChan cha
 // is guaranteed to always be called from the same goroutine. To shutdown the started
 // goroutines, either read all items from the channel or cancel the context. Then `Wait()`
 // on the errgroup until all goroutines were stopped.
-func StreamTrees(ctx context.Context, wg *errgroup.Group, repo TreeLoader, trees IDs, skip func(tree ID) bool, p *progress.Counter) <-chan TreeItem {
+func StreamTrees(ctx context.Context, wg *errgroup.Group, repo Loader, trees IDs, skip func(tree ID) bool, p *progress.Counter) <-chan TreeItem {
 	loaderChan := make(chan trackedID)
 	hugeTreeChan := make(chan trackedID, 10)
 	loadedTreeChan := make(chan trackedTreeItem)

internal/restic/tree_test.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 	"testing"
 
+	"github.com/restic/restic/internal/archiver"
 	"github.com/restic/restic/internal/repository"
 	"github.com/restic/restic/internal/restic"
 	rtest "github.com/restic/restic/internal/test"
@@ -95,7 +96,7 @@ func TestNodeComparison(t *testing.T) {
 	rtest.Assert(t, !node.Equals(n2), "nodes are equal")
 }
 
-func TestLoadTree(t *testing.T) {
+func TestEmptyLoadTree(t *testing.T) {
 	repo, cleanup := repository.TestRepository(t)
 	defer cleanup()
 
@@ -103,14 +104,14 @@ func TestLoadTree(t *testing.T) {
 	repo.StartPackUploader(context.TODO(), &wg)
 	// save tree
 	tree := restic.NewTree(0)
-	id, err := repo.SaveTree(context.TODO(), tree)
+	id, err := restic.SaveTree(context.TODO(), repo, tree)
 	rtest.OK(t, err)
 
 	// save packs
 	rtest.OK(t, repo.Flush(context.Background()))
 
 	// load tree again
-	tree2, err := repo.LoadTree(context.TODO(), id)
+	tree2, err := restic.LoadTree(context.TODO(), repo, id)
 	rtest.OK(t, err)
 
 	rtest.Assert(t, tree.Equals(tree2),
@@ -138,3 +139,47 @@ func BenchmarkBuildTree(b *testing.B) {
 		}
 	}
 }
+
+func TestLoadTree(t *testing.T) {
+	repository.TestAllVersions(t, testLoadTree)
+}
+
+func testLoadTree(t *testing.T, version uint) {
+	repo, cleanup := repository.TestRepositoryWithVersion(t, version)
+	defer cleanup()
+
+	if rtest.BenchArchiveDirectory == "" {
+		t.Skip("benchdir not set, skipping")
+	}
+
+	// archive a few files
+	sn := archiver.TestSnapshot(t, repo, rtest.BenchArchiveDirectory, nil)
+	rtest.OK(t, repo.Flush(context.Background()))
+
+	_, err := restic.LoadTree(context.TODO(), repo, *sn.Tree)
+	rtest.OK(t, err)
+}
+
+func BenchmarkLoadTree(t *testing.B) {
+	repository.BenchmarkAllVersions(t, benchmarkLoadTree)
+}
+
+func benchmarkLoadTree(t *testing.B, version uint) {
+	repo, cleanup := repository.TestRepositoryWithVersion(t, version)
+	defer cleanup()
+
+	if rtest.BenchArchiveDirectory == "" {
+		t.Skip("benchdir not set, skipping")
+	}
+
+	// archive a few files
+	sn := archiver.TestSnapshot(t, repo, rtest.BenchArchiveDirectory, nil)
+	rtest.OK(t, repo.Flush(context.Background()))
+
+	t.ResetTimer()
+
+	for i := 0; i < t.N; i++ {
+		_, err := restic.LoadTree(context.TODO(), repo, *sn.Tree)
+		rtest.OK(t, err)
+	}
+}

internal/restorer/restorer.go

@@ -53,7 +53,7 @@ type treeVisitor struct {
 // target is the path in the file system, location within the snapshot.
 func (res *Restorer) traverseTree(ctx context.Context, target, location string, treeID restic.ID, visitor treeVisitor) (hasRestored bool, err error) {
 	debug.Log("%v %v %v", target, location, treeID)
-	tree, err := res.repo.LoadTree(ctx, treeID)
+	tree, err := restic.LoadTree(ctx, res.repo, treeID)
 	if err != nil {
 		debug.Log("error loading tree %v: %v", treeID, err)
 		return hasRestored, res.Error(location, err)

internal/restorer/restorer_test.go

@@ -111,7 +111,7 @@ func saveDir(t testing.TB, repo restic.Repository, nodes map[string]Node, inode
 		}
 	}
 
-	id, err := repo.SaveTree(ctx, tree)
+	id, err := restic.SaveTree(ctx, repo, tree)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -137,7 +137,7 @@ func saveSnapshot(t testing.TB, repo restic.Repository, snapshot Snapshot) (*res
 	}
 
 	sn.Tree = &treeID
-	id, err := repo.SaveJSONUnpacked(ctx, restic.SnapshotFile, sn)
+	id, err := restic.SaveSnapshot(ctx, repo, sn)
 	if err != nil {
 		t.Fatal(err)
 	}

internal/walker/walker.go

@@ -10,11 +10,6 @@ import (
 	"github.com/restic/restic/internal/restic"
 )
 
-// TreeLoader loads a tree from a repository.
-type TreeLoader interface {
-	LoadTree(context.Context, restic.ID) (*restic.Tree, error)
-}
-
 // ErrSkipNode is returned by WalkFunc when a dir node should not be walked.
 var ErrSkipNode = errors.New("skip this node")
 
@@ -38,8 +33,8 @@ type WalkFunc func(parentTreeID restic.ID, path string, node *restic.Node, nodeE
 // Walk calls walkFn recursively for each node in root. If walkFn returns an
 // error, it is passed up the call stack. The trees in ignoreTrees are not
 // walked. If walkFn ignores trees, these are added to the set.
-func Walk(ctx context.Context, repo TreeLoader, root restic.ID, ignoreTrees restic.IDSet, walkFn WalkFunc) error {
+func Walk(ctx context.Context, repo restic.BlobLoader, root restic.ID, ignoreTrees restic.IDSet, walkFn WalkFunc) error {
-	tree, err := repo.LoadTree(ctx, root)
+	tree, err := restic.LoadTree(ctx, repo, root)
 	_, err = walkFn(root, "/", nil, err)
 
 	if err != nil {
@@ -60,7 +55,7 @@ func Walk(ctx context.Context, repo TreeLoader, root restic.ID, ignoreTrees rest
 // walk recursively traverses the tree, ignoring subtrees when the ID of the
 // subtree is in ignoreTrees. If err is nil and ignore is true, the subtree ID
 // will be added to ignoreTrees by walk.
-func walk(ctx context.Context, repo TreeLoader, prefix string, parentTreeID restic.ID, tree *restic.Tree, ignoreTrees restic.IDSet, walkFn WalkFunc) (ignore bool, err error) {
+func walk(ctx context.Context, repo restic.BlobLoader, prefix string, parentTreeID restic.ID, tree *restic.Tree, ignoreTrees restic.IDSet, walkFn WalkFunc) (ignore bool, err error) {
 	var allNodesIgnored = true
 
 	if len(tree.Nodes) == 0 {
@@ -104,7 +99,7 @@ func walk(ctx context.Context, repo TreeLoader, prefix string, parentTreeID rest
 			continue
 		}
 
-		subtree, err := repo.LoadTree(ctx, *node.Subtree)
+		subtree, err := restic.LoadTree(ctx, repo, *node.Subtree)
 		ignore, err := walkFn(parentTreeID, p, node, err)
 		if err != nil {
 			if err == ErrSkipNode {

internal/walker/walker_test.go

@@ -67,13 +67,22 @@ func buildTreeMap(tree TestTree, m TreeMap) restic.ID {
 // TreeMap returns the trees from the map on LoadTree.
 type TreeMap map[restic.ID]*restic.Tree
 
-func (t TreeMap) LoadTree(ctx context.Context, id restic.ID) (*restic.Tree, error) {
+func (t TreeMap) LoadBlob(ctx context.Context, tpe restic.BlobType, id restic.ID, buf []byte) ([]byte, error) {
+	if tpe != restic.TreeBlob {
+		return nil, errors.New("can only load trees")
+	}
 	tree, ok := t[id]
 	if !ok {
 		return nil, errors.New("tree not found")
 	}
 
-	return tree, nil
+	tbuf, err := json.Marshal(tree)
+	if err != nil {
+		panic(err)
+	}
+	tbuf = append(tbuf, '\n')
+
+	return tbuf, nil
 }
 
 func (t TreeMap) Connections() uint {