Move top level packages to internal.

internal/scanner/blockqueue.go

@@ -0,0 +1,73 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package scanner
+
+import (
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/syncthing/syncthing/internal/protocol"
+)
+
+// The parallell hasher reads FileInfo structures from the inbox, hashes the
+// file to populate the Blocks element and sends it to the outbox. A number of
+// workers are used in parallel. The outbox will become closed when the inbox
+// is closed and all items handled.
+
+func newParallelHasher(dir string, blockSize, workers int, outbox, inbox chan protocol.FileInfo) {
+	var wg sync.WaitGroup
+	wg.Add(workers)
+
+	for i := 0; i < workers; i++ {
+		go func() {
+			hashFile(dir, blockSize, outbox, inbox)
+			wg.Done()
+		}()
+	}
+
+	go func() {
+		wg.Wait()
+		close(outbox)
+	}()
+}
+
+func hashFile(dir string, blockSize int, outbox, inbox chan protocol.FileInfo) {
+	for f := range inbox {
+		if protocol.IsDirectory(f.Flags) || protocol.IsDeleted(f.Flags) {
+			outbox <- f
+			continue
+		}
+
+		fd, err := os.Open(filepath.Join(dir, f.Name))
+		if err != nil {
+			if debug {
+				l.Debugln("open:", err)
+			}
+			continue
+		}
+
+		fi, err := fd.Stat()
+		if err != nil {
+			fd.Close()
+			if debug {
+				l.Debugln("stat:", err)
+			}
+			continue
+		}
+		blocks, err := Blocks(fd, blockSize, fi.Size())
+		fd.Close()
+
+		if err != nil {
+			if debug {
+				l.Debugln("hash error:", f.Name, err)
+			}
+			continue
+		}
+
+		f.Blocks = blocks
+		outbox <- f
+	}
+}

internal/scanner/blocks.go

@@ -0,0 +1,90 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package scanner
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"io"
+
+	"github.com/syncthing/syncthing/internal/protocol"
+)
+
+const StandardBlockSize = 128 * 1024
+
+var sha256OfNothing = []uint8{0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14, 0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24, 0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c, 0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55}
+
+// Blocks returns the blockwise hash of the reader.
+func Blocks(r io.Reader, blocksize int, sizehint int64) ([]protocol.BlockInfo, error) {
+	var blocks []protocol.BlockInfo
+	if sizehint > 0 {
+		blocks = make([]protocol.BlockInfo, 0, int(sizehint/int64(blocksize)))
+	}
+	var offset int64
+	hf := sha256.New()
+	for {
+		lr := &io.LimitedReader{R: r, N: int64(blocksize)}
+		n, err := io.Copy(hf, lr)
+		if err != nil {
+			return nil, err
+		}
+
+		if n == 0 {
+			break
+		}
+
+		b := protocol.BlockInfo{
+			Size:   uint32(n),
+			Offset: offset,
+			Hash:   hf.Sum(nil),
+		}
+		blocks = append(blocks, b)
+		offset += int64(n)
+
+		hf.Reset()
+	}
+
+	if len(blocks) == 0 {
+		// Empty file
+		blocks = append(blocks, protocol.BlockInfo{
+			Offset: 0,
+			Size:   0,
+			Hash:   sha256OfNothing,
+		})
+	}
+
+	return blocks, nil
+}
+
+// BlockDiff returns lists of common and missing (to transform src into tgt)
+// blocks. Both block lists must have been created with the same block size.
+func BlockDiff(src, tgt []protocol.BlockInfo) (have, need []protocol.BlockInfo) {
+	if len(tgt) == 0 && len(src) != 0 {
+		return nil, nil
+	}
+
+	// Set the Offset field on each target block
+	var offset int64
+	for i := range tgt {
+		tgt[i].Offset = offset
+		offset += int64(tgt[i].Size)
+	}
+
+	if len(tgt) != 0 && len(src) == 0 {
+		// Copy the entire file
+		return nil, tgt
+	}
+
+	for i := range tgt {
+		if i >= len(src) || bytes.Compare(tgt[i].Hash, src[i].Hash) != 0 {
+			// Copy differing block
+			need = append(need, tgt[i])
+		} else {
+			have = append(have, tgt[i])
+		}
+	}
+
+	return have, need
+}

internal/scanner/blocks_test.go

@@ -0,0 +1,122 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package scanner
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"github.com/syncthing/syncthing/internal/protocol"
+)
+
+var blocksTestData = []struct {
+	data      []byte
+	blocksize int
+	hash      []string
+}{
+	{[]byte(""), 1024, []string{
+		"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"}},
+	{[]byte("contents"), 1024, []string{
+		"d1b2a59fbea7e20077af9f91b27e95e865061b270be03ff539ab3b73587882e8"}},
+	{[]byte("contents"), 9, []string{
+		"d1b2a59fbea7e20077af9f91b27e95e865061b270be03ff539ab3b73587882e8"}},
+	{[]byte("contents"), 8, []string{
+		"d1b2a59fbea7e20077af9f91b27e95e865061b270be03ff539ab3b73587882e8"}},
+	{[]byte("contents"), 7, []string{
+		"ed7002b439e9ac845f22357d822bac1444730fbdb6016d3ec9432297b9ec9f73",
+		"043a718774c572bd8a25adbeb1bfcd5c0256ae11cecf9f9c3f925d0e52beaf89"},
+	},
+	{[]byte("contents"), 3, []string{
+		"1143da2bc54c495c4be31d3868785d39ffdfd56df5668f0645d8f14d47647952",
+		"e4432baa90819aaef51d2a7f8e148bf7e679610f3173752fabb4dcb2d0f418d3",
+		"44ad63f60af0f6db6fdde6d5186ef78176367df261fa06be3079b6c80c8adba4"},
+	},
+	{[]byte("conconts"), 3, []string{
+		"1143da2bc54c495c4be31d3868785d39ffdfd56df5668f0645d8f14d47647952",
+		"1143da2bc54c495c4be31d3868785d39ffdfd56df5668f0645d8f14d47647952",
+		"44ad63f60af0f6db6fdde6d5186ef78176367df261fa06be3079b6c80c8adba4"},
+	},
+	{[]byte("contenten"), 3, []string{
+		"1143da2bc54c495c4be31d3868785d39ffdfd56df5668f0645d8f14d47647952",
+		"e4432baa90819aaef51d2a7f8e148bf7e679610f3173752fabb4dcb2d0f418d3",
+		"e4432baa90819aaef51d2a7f8e148bf7e679610f3173752fabb4dcb2d0f418d3"},
+	},
+}
+
+func TestBlocks(t *testing.T) {
+	for _, test := range blocksTestData {
+		buf := bytes.NewBuffer(test.data)
+		blocks, err := Blocks(buf, test.blocksize, 0)
+
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if l := len(blocks); l != len(test.hash) {
+			t.Fatalf("Incorrect number of blocks %d != %d", l, len(test.hash))
+		} else {
+			i := 0
+			for off := int64(0); off < int64(len(test.data)); off += int64(test.blocksize) {
+				if blocks[i].Offset != off {
+					t.Errorf("Incorrect offset for block %d: %d != %d", i, blocks[i].Offset, off)
+				}
+
+				bs := test.blocksize
+				if rem := len(test.data) - int(off); bs > rem {
+					bs = rem
+				}
+				if int(blocks[i].Size) != bs {
+					t.Errorf("Incorrect length for block %d: %d != %d", i, blocks[i].Size, bs)
+				}
+				if h := fmt.Sprintf("%x", blocks[i].Hash); h != test.hash[i] {
+					t.Errorf("Incorrect block hash %q != %q", h, test.hash[i])
+				}
+
+				i++
+			}
+		}
+	}
+}
+
+var diffTestData = []struct {
+	a string
+	b string
+	s int
+	d []protocol.BlockInfo
+}{
+	{"contents", "contents", 1024, []protocol.BlockInfo{}},
+	{"", "", 1024, []protocol.BlockInfo{}},
+	{"contents", "contents", 3, []protocol.BlockInfo{}},
+	{"contents", "cantents", 3, []protocol.BlockInfo{{0, 3, nil}}},
+	{"contents", "contants", 3, []protocol.BlockInfo{{3, 3, nil}}},
+	{"contents", "cantants", 3, []protocol.BlockInfo{{0, 3, nil}, {3, 3, nil}}},
+	{"contents", "", 3, []protocol.BlockInfo{{0, 0, nil}}},
+	{"", "contents", 3, []protocol.BlockInfo{{0, 3, nil}, {3, 3, nil}, {6, 2, nil}}},
+	{"con", "contents", 3, []protocol.BlockInfo{{3, 3, nil}, {6, 2, nil}}},
+	{"contents", "con", 3, nil},
+	{"contents", "cont", 3, []protocol.BlockInfo{{3, 1, nil}}},
+	{"cont", "contents", 3, []protocol.BlockInfo{{3, 3, nil}, {6, 2, nil}}},
+}
+
+func TestDiff(t *testing.T) {
+	for i, test := range diffTestData {
+		a, _ := Blocks(bytes.NewBufferString(test.a), test.s, 0)
+		b, _ := Blocks(bytes.NewBufferString(test.b), test.s, 0)
+		_, d := BlockDiff(a, b)
+		if len(d) != len(test.d) {
+			t.Fatalf("Incorrect length for diff %d; %d != %d", i, len(d), len(test.d))
+		} else {
+			for j := range test.d {
+				if d[j].Offset != test.d[j].Offset {
+					t.Errorf("Incorrect offset for diff %d block %d; %d != %d", i, j, d[j].Offset, test.d[j].Offset)
+				}
+				if d[j].Size != test.d[j].Size {
+					t.Errorf("Incorrect length for diff %d block %d; %d != %d", i, j, d[j].Size, test.d[j].Size)
+				}
+			}
+		}
+	}
+}

internal/scanner/debug.go

@@ -0,0 +1,17 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package scanner
+
+import (
+	"os"
+	"strings"
+
+	"github.com/syncthing/syncthing/internal/logger"
+)
+
+var (
+	debug = strings.Contains(os.Getenv("STTRACE"), "scanner") || os.Getenv("STTRACE") == "all"
+	l     = logger.DefaultLogger
+)

internal/scanner/doc.go

@@ -0,0 +1,6 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+// Package scanner implements a file system scanner and hasher.
+package scanner

internal/scanner/testdata/.stignore

@@ -0,0 +1,4 @@
+#include excludes
+
+bfile
+dir1/cfile

internal/scanner/testdata/afile

@@ -0,0 +1 @@
+foo

internal/scanner/testdata/bfile

@@ -0,0 +1 @@
+bar

internal/scanner/testdata/dir1/cfile

@@ -0,0 +1 @@
+baz

internal/scanner/testdata/dir1/dfile

@@ -0,0 +1 @@
+quux

internal/scanner/testdata/dir2/cfile

@@ -0,0 +1 @@
+baz

internal/scanner/testdata/dir2/dfile

@@ -0,0 +1 @@
+quux

internal/scanner/testdata/dir3/cfile

@@ -0,0 +1 @@
+baz

internal/scanner/testdata/dir3/dfile

@@ -0,0 +1 @@
+quux

internal/scanner/testdata/excludes

@@ -0,0 +1,2 @@
+dir2/dfile
+#include further-excludes

internal/scanner/testdata/further-excludes

@@ -0,0 +1 @@
+dir3

internal/scanner/walk.go

@@ -0,0 +1,215 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package scanner
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"code.google.com/p/go.text/unicode/norm"
+
+	"github.com/syncthing/syncthing/internal/ignore"
+	"github.com/syncthing/syncthing/internal/lamport"
+	"github.com/syncthing/syncthing/internal/protocol"
+)
+
+type Walker struct {
+	// Dir is the base directory for the walk
+	Dir string
+	// Limit walking to this path within Dir, or no limit if Sub is blank
+	Sub string
+	// BlockSize controls the size of the block used when hashing.
+	BlockSize int
+	// List of patterns to ignore
+	Ignores ignore.Patterns
+	// If TempNamer is not nil, it is used to ignore tempory files when walking.
+	TempNamer TempNamer
+	// If CurrentFiler is not nil, it is queried for the current file before rescanning.
+	CurrentFiler CurrentFiler
+	// If IgnorePerms is true, changes to permission bits will not be
+	// detected. Scanned files will get zero permission bits and the
+	// NoPermissionBits flag set.
+	IgnorePerms bool
+}
+
+type TempNamer interface {
+	// Temporary returns a temporary name for the filed referred to by filepath.
+	TempName(path string) string
+	// IsTemporary returns true if path refers to the name of temporary file.
+	IsTemporary(path string) bool
+}
+
+type CurrentFiler interface {
+	// CurrentFile returns the file as seen at last scan.
+	CurrentFile(name string) protocol.FileInfo
+}
+
+// Walk returns the list of files found in the local repository by scanning the
+// file system. Files are blockwise hashed.
+func (w *Walker) Walk() (chan protocol.FileInfo, error) {
+	if debug {
+		l.Debugln("Walk", w.Dir, w.Sub, w.BlockSize, w.Ignores)
+	}
+
+	err := checkDir(w.Dir)
+	if err != nil {
+		return nil, err
+	}
+
+	files := make(chan protocol.FileInfo)
+	hashedFiles := make(chan protocol.FileInfo)
+	newParallelHasher(w.Dir, w.BlockSize, runtime.NumCPU(), hashedFiles, files)
+
+	go func() {
+		hashFiles := w.walkAndHashFiles(files)
+		filepath.Walk(filepath.Join(w.Dir, w.Sub), hashFiles)
+		close(files)
+	}()
+
+	return hashedFiles, nil
+}
+
+// CleanTempFiles removes all files that match the temporary filename pattern.
+func (w *Walker) CleanTempFiles() {
+	filepath.Walk(w.Dir, w.cleanTempFile)
+}
+
+func (w *Walker) walkAndHashFiles(fchan chan protocol.FileInfo) filepath.WalkFunc {
+	return func(p string, info os.FileInfo, err error) error {
+		if err != nil {
+			if debug {
+				l.Debugln("error:", p, info, err)
+			}
+			return nil
+		}
+
+		rn, err := filepath.Rel(w.Dir, p)
+		if err != nil {
+			if debug {
+				l.Debugln("rel error:", p, err)
+			}
+			return nil
+		}
+
+		if rn == "." {
+			return nil
+		}
+
+		if w.TempNamer != nil && w.TempNamer.IsTemporary(rn) {
+			// A temporary file
+			if debug {
+				l.Debugln("temporary:", rn)
+			}
+			return nil
+		}
+
+		if sn := filepath.Base(rn); sn == ".stignore" || sn == ".stversions" || w.Ignores.Match(rn) {
+			// An ignored file
+			if debug {
+				l.Debugln("ignored:", rn)
+			}
+			if info.IsDir() {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+
+		if (runtime.GOOS == "linux" || runtime.GOOS == "windows") && !norm.NFC.IsNormalString(rn) {
+			l.Warnf("File %q contains non-NFC UTF-8 sequences and cannot be synced. Consider renaming.", rn)
+			return nil
+		}
+
+		if info.Mode().IsDir() {
+			if w.CurrentFiler != nil {
+				cf := w.CurrentFiler.CurrentFile(rn)
+				permUnchanged := w.IgnorePerms || !protocol.HasPermissionBits(cf.Flags) || PermsEqual(cf.Flags, uint32(info.Mode()))
+				if !protocol.IsDeleted(cf.Flags) && protocol.IsDirectory(cf.Flags) && permUnchanged {
+					return nil
+				}
+			}
+
+			var flags uint32 = protocol.FlagDirectory
+			if w.IgnorePerms {
+				flags |= protocol.FlagNoPermBits | 0777
+			} else {
+				flags |= uint32(info.Mode() & os.ModePerm)
+			}
+			f := protocol.FileInfo{
+				Name:     rn,
+				Version:  lamport.Default.Tick(0),
+				Flags:    flags,
+				Modified: info.ModTime().Unix(),
+			}
+			if debug {
+				l.Debugln("dir:", f)
+			}
+			fchan <- f
+			return nil
+		}
+
+		if info.Mode().IsRegular() {
+			if w.CurrentFiler != nil {
+				cf := w.CurrentFiler.CurrentFile(rn)
+				permUnchanged := w.IgnorePerms || !protocol.HasPermissionBits(cf.Flags) || PermsEqual(cf.Flags, uint32(info.Mode()))
+				if !protocol.IsDeleted(cf.Flags) && cf.Modified == info.ModTime().Unix() && permUnchanged {
+					return nil
+				}
+
+				if debug {
+					l.Debugln("rescan:", cf, info.ModTime().Unix(), info.Mode()&os.ModePerm)
+				}
+			}
+
+			var flags = uint32(info.Mode() & os.ModePerm)
+			if w.IgnorePerms {
+				flags = protocol.FlagNoPermBits | 0666
+			}
+
+			fchan <- protocol.FileInfo{
+				Name:     rn,
+				Version:  lamport.Default.Tick(0),
+				Flags:    flags,
+				Modified: info.ModTime().Unix(),
+			}
+		}
+
+		return nil
+	}
+}
+
+func (w *Walker) cleanTempFile(path string, info os.FileInfo, err error) error {
+	if err != nil {
+		return err
+	}
+	if info.Mode()&os.ModeType == 0 && w.TempNamer.IsTemporary(path) {
+		os.Remove(path)
+	}
+	return nil
+}
+
+func checkDir(dir string) error {
+	if info, err := os.Lstat(dir); err != nil {
+		return err
+	} else if !info.IsDir() {
+		return errors.New(dir + ": not a directory")
+	} else if debug {
+		l.Debugln("checkDir", dir, info)
+	}
+	return nil
+}
+
+func PermsEqual(a, b uint32) bool {
+	switch runtime.GOOS {
+	case "windows":
+		// There is only writeable and read only, represented for user, group
+		// and other equally. We only compare against user.
+		return a&0600 == b&0600
+	default:
+		// All bits count
+		return a&0777 == b&0777
+	}
+}

internal/scanner/walk_test.go

@@ -0,0 +1,172 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package scanner
+
+import (
+	"bytes"
+	"fmt"
+	"path/filepath"
+	"reflect"
+	rdebug "runtime/debug"
+	"sort"
+	"testing"
+
+	"github.com/syncthing/syncthing/internal/ignore"
+	"github.com/syncthing/syncthing/internal/protocol"
+)
+
+type testfile struct {
+	name string
+	size int
+	hash string
+}
+
+type testfileList []testfile
+
+var testdata = testfileList{
+	{"afile", 4, "b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b878ae4944c"},
+	{"dir1", 128, ""},
+	{filepath.Join("dir1", "dfile"), 5, "49ae93732fcf8d63fe1cce759664982dbd5b23161f007dba8561862adc96d063"},
+	{"dir2", 128, ""},
+	{filepath.Join("dir2", "cfile"), 4, "bf07a7fbb825fc0aae7bf4a1177b2b31fcf8a3feeaf7092761e18c859ee52a9c"},
+	{"excludes", 37, "df90b52f0c55dba7a7a940affe482571563b1ac57bd5be4d8a0291e7de928e06"},
+	{"further-excludes", 5, "7eb0a548094fa6295f7fd9200d69973e5f5ec5c04f2a86d998080ac43ecf89f1"},
+}
+
+var correctIgnores = map[string][]string{
+	".": {".*", "quux"},
+}
+
+func init() {
+	// This test runs the risk of entering infinite recursion if it fails.
+	// Limit the stack size to 10 megs to creash early in that case instead of
+	// potentially taking down the box...
+	rdebug.SetMaxStack(10 * 1 << 20)
+}
+
+func TestWalkSub(t *testing.T) {
+	ignores, err := ignore.Load("testdata/.stignore")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	w := Walker{
+		Dir:       "testdata",
+		Sub:       "dir2",
+		BlockSize: 128 * 1024,
+		Ignores:   ignores,
+	}
+	fchan, err := w.Walk()
+	var files []protocol.FileInfo
+	for f := range fchan {
+		files = append(files, f)
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// The directory contains two files, where one is ignored from a higher
+	// level. We should see only the directory and one of the files.
+
+	if len(files) != 2 {
+		t.Fatalf("Incorrect length %d != 2", len(files))
+	}
+	if files[0].Name != "dir2" {
+		t.Errorf("Incorrect file %v != dir2", files[0])
+	}
+	if files[1].Name != filepath.Join("dir2", "cfile") {
+		t.Errorf("Incorrect file %v != dir2/cfile", files[1])
+	}
+}
+
+func TestWalk(t *testing.T) {
+	ignores, err := ignore.Load("testdata/.stignore")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Log(ignores)
+
+	w := Walker{
+		Dir:       "testdata",
+		BlockSize: 128 * 1024,
+		Ignores:   ignores,
+	}
+
+	fchan, err := w.Walk()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var tmp []protocol.FileInfo
+	for f := range fchan {
+		tmp = append(tmp, f)
+	}
+	sort.Sort(fileList(tmp))
+	files := fileList(tmp).testfiles()
+
+	if !reflect.DeepEqual(files, testdata) {
+		t.Errorf("Walk returned unexpected data\nExpected: %v\nActual: %v", testdata, files)
+	}
+}
+
+func TestWalkError(t *testing.T) {
+	w := Walker{
+		Dir:       "testdata-missing",
+		BlockSize: 128 * 1024,
+	}
+	_, err := w.Walk()
+
+	if err == nil {
+		t.Error("no error from missing directory")
+	}
+
+	w = Walker{
+		Dir:       "testdata/bar",
+		BlockSize: 128 * 1024,
+	}
+	_, err = w.Walk()
+
+	if err == nil {
+		t.Error("no error from non-directory")
+	}
+}
+
+type fileList []protocol.FileInfo
+
+func (f fileList) Len() int {
+	return len(f)
+}
+
+func (f fileList) Less(a, b int) bool {
+	return f[a].Name < f[b].Name
+}
+
+func (f fileList) Swap(a, b int) {
+	f[a], f[b] = f[b], f[a]
+}
+
+func (l fileList) testfiles() testfileList {
+	testfiles := make(testfileList, len(l))
+	for i, f := range l {
+		if len(f.Blocks) > 1 {
+			panic("simple test case stuff only supports a single block per file")
+		}
+		testfiles[i] = testfile{name: f.Name, size: int(f.Size())}
+		if len(f.Blocks) == 1 {
+			testfiles[i].hash = fmt.Sprintf("%x", f.Blocks[0].Hash)
+		}
+	}
+	return testfiles
+}
+
+func (l testfileList) String() string {
+	var b bytes.Buffer
+	b.WriteString("{\n")
+	for _, f := range l {
+		fmt.Fprintf(&b, "  %s (%d bytes): %s\n", f.name, f.size, f.hash)
+	}
+	b.WriteString("}")
+	return b.String()
+}