fuse: refactor and add tests for fuse.file

cmd/restic/fuse/file.go

@@ -4,8 +4,8 @@ import (
 	"sync"
 
 	"github.com/restic/restic"
+	"github.com/restic/restic/backend"
 	"github.com/restic/restic/pack"
-	"github.com/restic/restic/repository"
 
 	"bazil.org/fuse"
 	"bazil.org/fuse/fs"
@@ -16,11 +16,18 @@ import (
 var _ = fs.HandleReader(&file{})
 var _ = fs.HandleReleaser(&file{})
 
+// BlobLoader is an abstracted repository with a reduced set of methods used
+// for fuse operations.
+type BlobLoader interface {
+	LookupBlobSize(backend.ID) (uint, error)
+	LoadBlob(pack.BlobType, backend.ID, []byte) ([]byte, error)
+}
+
 type file struct {
-	repo *repository.Repository
+	repo BlobLoader
 	node *restic.Node
 
-	sizes []uint32
+	sizes []uint
 	blobs [][]byte
 }
 
@@ -32,14 +39,15 @@ var blobPool = sync.Pool{
 	},
 }
 
-func newFile(repo *repository.Repository, node *restic.Node) (*file, error) {
-	sizes := make([]uint32, len(node.Content))
-	for i, blobID := range node.Content {
-		length, err := repo.Index().LookupSize(blobID)
+func newFile(repo BlobLoader, node *restic.Node) (*file, error) {
+	sizes := make([]uint, len(node.Content))
+	for i, id := range node.Content {
+		size, err := repo.LookupBlobSize(id)
 		if err != nil {
 			return nil, err
 		}
-		sizes[i] = uint32(length)
+
+		sizes[i] = size
 	}
 
 	return &file{
@@ -65,7 +73,7 @@ func (f *file) getBlobAt(i int) (blob []byte, err error) {
 	buf := blobPool.Get().([]byte)
 	buf = buf[:cap(buf)]
 
-	if uint32(len(buf)) < f.sizes[i] {
+	if uint(len(buf)) < f.sizes[i] {
 		if len(buf) > defaultBlobSize {
 			blobPool.Put(buf)
 		}

cmd/restic/fuse/file_test.go

@@ -0,0 +1,157 @@
+package fuse
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"math/rand"
+	"testing"
+	"time"
+
+	"bazil.org/fuse"
+
+	"github.com/restic/restic"
+	"github.com/restic/restic/backend"
+	"github.com/restic/restic/pack"
+	. "github.com/restic/restic/test"
+)
+
+type MockRepo struct {
+	blobs map[backend.ID][]byte
+}
+
+func NewMockRepo(content map[backend.ID][]byte) *MockRepo {
+	return &MockRepo{blobs: content}
+}
+
+func (m *MockRepo) LookupBlobSize(id backend.ID) (uint, error) {
+	buf, ok := m.blobs[id]
+	if !ok {
+		return 0, errors.New("blob not found")
+	}
+
+	return uint(len(buf)), nil
+}
+
+func (m *MockRepo) LoadBlob(t pack.BlobType, id backend.ID, buf []byte) ([]byte, error) {
+	size, err := m.LookupBlobSize(id)
+	if err != nil {
+		return nil, err
+	}
+
+	if uint(cap(buf)) < size {
+		return nil, errors.New("buffer too small")
+	}
+
+	buf = buf[:size]
+	copy(buf, m.blobs[id])
+	return buf, nil
+}
+
+type MockContext struct{}
+
+func (m MockContext) Deadline() (time.Time, bool)       { return time.Now(), false }
+func (m MockContext) Done() <-chan struct{}             { return nil }
+func (m MockContext) Err() error                        { return nil }
+func (m MockContext) Value(key interface{}) interface{} { return nil }
+
+var testContent = genTestContent()
+var testContentLengths = []uint{
+	4646 * 1024,
+	655 * 1024,
+	378 * 1024,
+	8108 * 1024,
+	558 * 1024,
+}
+var testMaxFileSize uint
+
+func genTestContent() map[backend.ID][]byte {
+	m := make(map[backend.ID][]byte)
+
+	for _, length := range testContentLengths {
+		buf := Random(int(length), int(length))
+		id := backend.Hash(buf)
+		m[id] = buf
+		testMaxFileSize += length
+	}
+
+	return m
+}
+
+const maxBufSize = 20 * 1024 * 1024
+
+func testRead(t *testing.T, f *file, offset, length int, data []byte) []byte {
+	ctx := MockContext{}
+
+	req := &fuse.ReadRequest{
+		Offset: int64(offset),
+		Size:   length,
+	}
+	resp := &fuse.ReadResponse{
+		Data: make([]byte, length),
+	}
+	OK(t, f.Read(ctx, req, resp))
+
+	return resp.Data
+}
+
+var offsetReadsTests = []struct {
+	offset, length int
+}{
+	{0, 5 * 1024 * 1024},
+	{4000 * 1024, 1000 * 1024},
+}
+
+func TestFuseFile(t *testing.T) {
+	repo := NewMockRepo(testContent)
+	ctx := MockContext{}
+
+	memfile := make([]byte, 0, maxBufSize)
+
+	var ids backend.IDs
+	for id, buf := range repo.blobs {
+		ids = append(ids, id)
+		memfile = append(memfile, buf...)
+	}
+
+	node := &restic.Node{
+		Name:    "foo",
+		Inode:   23,
+		Mode:    0742,
+		Size:    42,
+		Content: ids,
+	}
+	f, err := newFile(repo, node)
+	OK(t, err)
+
+	attr := fuse.Attr{}
+	OK(t, f.Attr(ctx, &attr))
+
+	Equals(t, node.Inode, attr.Inode)
+	Equals(t, node.Mode, attr.Mode)
+	Equals(t, node.Size, attr.Size)
+
+	for i, test := range offsetReadsTests {
+		b := memfile[test.offset : test.offset+test.length]
+		res := testRead(t, f, test.offset, test.length, b)
+		if !bytes.Equal(b, res) {
+			t.Errorf("test %d failed, wrong data returned", i)
+		}
+	}
+
+	for i := 0; i < 200; i++ {
+		length := rand.Intn(int(testMaxFileSize) / 2)
+		offset := rand.Intn(int(testMaxFileSize))
+		if length+offset > int(testMaxFileSize) {
+			diff := length + offset - int(testMaxFileSize)
+			length -= diff
+		}
+
+		b := memfile[offset : offset+length]
+		fmt.Printf("test offset %d, length %d\n", offset, length)
+		res := testRead(t, f, offset, length, b)
+		if !bytes.Equal(b, res) {
+			t.Errorf("test %d failed (offset %d, length %d), wrong data returned", i, offset, length)
+		}
+	}
+}

repository/repository.go

@@ -201,6 +201,11 @@ func (r *Repository) LoadJSONPack(t pack.BlobType, id backend.ID, item interface
 	return nil
 }
 
+// LookupBlobSize returns the size of blob id.
+func (r *Repository) LookupBlobSize(id backend.ID) (uint, error) {
+	return r.Index().LookupSize(id)
+}
+
 const minPackSize = 4 * chunker.MiB
 const maxPackSize = 16 * chunker.MiB
 const maxPackers = 200