restic/internal/walker/rewriter_test.go
Michael Eischer 1bd1f3008d walker: extend TreeRewriter to support snapshot repairing
This adds support for caching already rewritten trees, handling of load
errors and disabling the check that the serialization doesn't lead to
data loss.
2023-05-01 15:20:24 +02:00

366 lines
8.2 KiB
Go

package walker
import (
"context"
"fmt"
"testing"
"github.com/pkg/errors"
"github.com/restic/restic/internal/restic"
"github.com/restic/restic/internal/test"
)
// WritableTreeMap also support saving
type WritableTreeMap struct {
TreeMap
}
func (t WritableTreeMap) SaveBlob(ctx context.Context, tpe restic.BlobType, buf []byte, id restic.ID, storeDuplicate bool) (newID restic.ID, known bool, size int, err error) {
if tpe != restic.TreeBlob {
return restic.ID{}, false, 0, errors.New("can only save trees")
}
if id.IsNull() {
id = restic.Hash(buf)
}
_, ok := t.TreeMap[id]
if ok {
return id, false, 0, nil
}
t.TreeMap[id] = append([]byte{}, buf...)
return id, true, len(buf), nil
}
func (t WritableTreeMap) Dump() {
for k, v := range t.TreeMap {
fmt.Printf("%v: %v", k, string(v))
}
}
type checkRewriteFunc func(t testing.TB) (rewriter *TreeRewriter, final func(testing.TB))
// checkRewriteItemOrder ensures that the order of the 'path' arguments is the one passed in as 'want'.
func checkRewriteItemOrder(want []string) checkRewriteFunc {
pos := 0
return func(t testing.TB) (rewriter *TreeRewriter, final func(testing.TB)) {
rewriter = NewTreeRewriter(RewriteOpts{
RewriteNode: func(node *restic.Node, path string) *restic.Node {
if pos >= len(want) {
t.Errorf("additional unexpected path found: %v", path)
return nil
}
if path != want[pos] {
t.Errorf("wrong path found, want %q, got %q", want[pos], path)
}
pos++
return node
},
})
final = func(t testing.TB) {
if pos != len(want) {
t.Errorf("not enough items returned, want %d, got %d", len(want), pos)
}
}
return rewriter, final
}
}
// checkRewriteSkips excludes nodes if path is in skipFor, it checks that rewriting proceedes in the correct order.
func checkRewriteSkips(skipFor map[string]struct{}, want []string, disableCache bool) checkRewriteFunc {
var pos int
return func(t testing.TB) (rewriter *TreeRewriter, final func(testing.TB)) {
rewriter = NewTreeRewriter(RewriteOpts{
RewriteNode: func(node *restic.Node, path string) *restic.Node {
if pos >= len(want) {
t.Errorf("additional unexpected path found: %v", path)
return nil
}
if path != want[pos] {
t.Errorf("wrong path found, want %q, got %q", want[pos], path)
}
pos++
_, skip := skipFor[path]
if skip {
return nil
}
return node
},
DisableNodeCache: disableCache,
})
final = func(t testing.TB) {
if pos != len(want) {
t.Errorf("not enough items returned, want %d, got %d", len(want), pos)
}
}
return rewriter, final
}
}
// checkIncreaseNodeSize modifies each node by changing its size.
func checkIncreaseNodeSize(increase uint64) checkRewriteFunc {
return func(t testing.TB) (rewriter *TreeRewriter, final func(testing.TB)) {
rewriter = NewTreeRewriter(RewriteOpts{
RewriteNode: func(node *restic.Node, path string) *restic.Node {
if node.Type == "file" {
node.Size += increase
}
return node
},
})
final = func(t testing.TB) {}
return rewriter, final
}
}
func TestRewriter(t *testing.T) {
var tests = []struct {
tree TestTree
newTree TestTree
check checkRewriteFunc
}{
{ // don't change
tree: TestTree{
"foo": TestFile{},
"subdir": TestTree{
"subfile": TestFile{},
},
},
check: checkRewriteItemOrder([]string{
"/foo",
"/subdir",
"/subdir/subfile",
}),
},
{ // exclude file
tree: TestTree{
"foo": TestFile{},
"subdir": TestTree{
"subfile": TestFile{},
},
},
newTree: TestTree{
"foo": TestFile{},
"subdir": TestTree{},
},
check: checkRewriteSkips(
map[string]struct{}{
"/subdir/subfile": {},
},
[]string{
"/foo",
"/subdir",
"/subdir/subfile",
},
false,
),
},
{ // exclude dir
tree: TestTree{
"foo": TestFile{},
"subdir": TestTree{
"subfile": TestFile{},
},
},
newTree: TestTree{
"foo": TestFile{},
},
check: checkRewriteSkips(
map[string]struct{}{
"/subdir": {},
},
[]string{
"/foo",
"/subdir",
},
false,
),
},
{ // modify node
tree: TestTree{
"foo": TestFile{Size: 21},
"subdir": TestTree{
"subfile": TestFile{Size: 21},
},
},
newTree: TestTree{
"foo": TestFile{Size: 42},
"subdir": TestTree{
"subfile": TestFile{Size: 42},
},
},
check: checkIncreaseNodeSize(21),
},
{ // test cache
tree: TestTree{
// both subdirs are identical
"subdir1": TestTree{
"subfile": TestFile{},
"subfile2": TestFile{},
},
"subdir2": TestTree{
"subfile": TestFile{},
"subfile2": TestFile{},
},
},
newTree: TestTree{
"subdir1": TestTree{
"subfile2": TestFile{},
},
"subdir2": TestTree{
"subfile2": TestFile{},
},
},
check: checkRewriteSkips(
map[string]struct{}{
"/subdir1/subfile": {},
},
[]string{
"/subdir1",
"/subdir1/subfile",
"/subdir1/subfile2",
"/subdir2",
},
false,
),
},
{ // test disabled cache
tree: TestTree{
// both subdirs are identical
"subdir1": TestTree{
"subfile": TestFile{},
"subfile2": TestFile{},
},
"subdir2": TestTree{
"subfile": TestFile{},
"subfile2": TestFile{},
},
},
newTree: TestTree{
"subdir1": TestTree{
"subfile2": TestFile{},
},
"subdir2": TestTree{
"subfile": TestFile{},
"subfile2": TestFile{},
},
},
check: checkRewriteSkips(
map[string]struct{}{
"/subdir1/subfile": {},
},
[]string{
"/subdir1",
"/subdir1/subfile",
"/subdir1/subfile2",
"/subdir2",
"/subdir2/subfile",
"/subdir2/subfile2",
},
true,
),
},
}
for _, test := range tests {
t.Run("", func(t *testing.T) {
repo, root := BuildTreeMap(test.tree)
if test.newTree == nil {
test.newTree = test.tree
}
expRepo, expRoot := BuildTreeMap(test.newTree)
modrepo := WritableTreeMap{repo}
ctx, cancel := context.WithCancel(context.TODO())
defer cancel()
rewriter, last := test.check(t)
newRoot, err := rewriter.RewriteTree(ctx, modrepo, "/", root)
if err != nil {
t.Error(err)
}
last(t)
// verifying against the expected tree root also implicitly checks the structural integrity
if newRoot != expRoot {
t.Error("hash mismatch")
fmt.Println("Got")
modrepo.Dump()
fmt.Println("Expected")
WritableTreeMap{expRepo}.Dump()
}
})
}
}
func TestRewriterFailOnUnknownFields(t *testing.T) {
tm := WritableTreeMap{TreeMap{}}
node := []byte(`{"nodes":[{"name":"subfile","type":"file","mtime":"0001-01-01T00:00:00Z","atime":"0001-01-01T00:00:00Z","ctime":"0001-01-01T00:00:00Z","uid":0,"gid":0,"content":null,"unknown_field":42}]}`)
id := restic.Hash(node)
tm.TreeMap[id] = node
ctx, cancel := context.WithCancel(context.TODO())
defer cancel()
rewriter := NewTreeRewriter(RewriteOpts{
RewriteNode: func(node *restic.Node, path string) *restic.Node {
// tree loading must not succeed
t.Fail()
return node
},
})
_, err := rewriter.RewriteTree(ctx, tm, "/", id)
if err == nil {
t.Error("missing error on unknown field")
}
// check that the serialization check can be disabled
rewriter = NewTreeRewriter(RewriteOpts{
AllowUnstableSerialization: true,
})
root, err := rewriter.RewriteTree(ctx, tm, "/", id)
test.OK(t, err)
_, expRoot := BuildTreeMap(TestTree{
"subfile": TestFile{},
})
test.Assert(t, root == expRoot, "mismatched trees")
}
func TestRewriterTreeLoadError(t *testing.T) {
tm := WritableTreeMap{TreeMap{}}
id := restic.NewRandomID()
ctx, cancel := context.WithCancel(context.TODO())
defer cancel()
// also check that load error by default cause the operation to fail
rewriter := NewTreeRewriter(RewriteOpts{})
_, err := rewriter.RewriteTree(ctx, tm, "/", id)
if err == nil {
t.Fatal("missing error on unloadable tree")
}
replacementID := restic.NewRandomID()
rewriter = NewTreeRewriter(RewriteOpts{
RewriteFailedTree: func(nodeID restic.ID, path string, err error) (restic.ID, error) {
if nodeID != id || path != "/" {
t.Fail()
}
return replacementID, nil
},
})
newRoot, err := rewriter.RewriteTree(ctx, tm, "/", id)
test.OK(t, err)
test.Equals(t, replacementID, newRoot)
}