backend: move backend implementation helpers to util package

This removes code that is only used within a backend implementation from
the backend package. The latter now only contains code that also has
external users.

internal/backend/azure/azure.go

@@ -12,9 +12,9 @@ import (
 	"path"
 	"strings"
 
-	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/backend/layout"
 	"github.com/restic/restic/internal/backend/location"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
@@ -295,7 +295,7 @@ func (be *Backend) saveLarge(ctx context.Context, objName string, rd restic.Rewi
 // Load runs fn with a reader that yields the contents of the file at h at the
 // given offset.
 func (be *Backend) Load(ctx context.Context, h restic.Handle, length int, offset int64, fn func(rd io.Reader) error) error {
-	return backend.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
+	return util.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
 }
 
 func (be *Backend) openReader(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
@@ -407,7 +407,7 @@ func (be *Backend) List(ctx context.Context, t restic.FileType, fn func(restic.F
 
 // Delete removes all restic keys in the bucket. It will not remove the bucket itself.
 func (be *Backend) Delete(ctx context.Context) error {
-	return backend.DefaultDelete(ctx, be)
+	return util.DefaultDelete(ctx, be)
 }
 
 // Close does nothing

internal/backend/b2/b2.go

@@ -9,9 +9,9 @@ import (
 	"sync"
 	"time"
 
-	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/backend/layout"
 	"github.com/restic/restic/internal/backend/location"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
@@ -192,7 +192,7 @@ func (be *b2Backend) Load(ctx context.Context, h restic.Handle, length int, offs
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	return backend.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
+	return util.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
 }
 
 func (be *b2Backend) openReader(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
@@ -313,7 +313,7 @@ func (be *b2Backend) List(ctx context.Context, t restic.FileType, fn func(restic
 
 // Delete removes all restic keys in the bucket. It will not remove the bucket itself.
 func (be *b2Backend) Delete(ctx context.Context) error {
-	return backend.DefaultDelete(ctx, be)
+	return util.DefaultDelete(ctx, be)
 }
 
 // Close does nothing

internal/backend/gs/gs.go

@@ -13,9 +13,9 @@ import (
 
 	"cloud.google.com/go/storage"
 	"github.com/pkg/errors"
-	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/backend/layout"
 	"github.com/restic/restic/internal/backend/location"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/restic"
 
@@ -257,7 +257,7 @@ func (be *Backend) Load(ctx context.Context, h restic.Handle, length int, offset
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	return backend.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
+	return util.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
 }
 
 func (be *Backend) openReader(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
@@ -350,7 +350,7 @@ func (be *Backend) List(ctx context.Context, t restic.FileType, fn func(restic.F
 
 // Delete removes all restic keys in the bucket. It will not remove the bucket itself.
 func (be *Backend) Delete(ctx context.Context) error {
-	return backend.DefaultDelete(ctx, be)
+	return util.DefaultDelete(ctx, be)
 }
 
 // Close does nothing.

internal/backend/local/local.go

@@ -12,6 +12,7 @@ import (
 	"github.com/restic/restic/internal/backend/layout"
 	"github.com/restic/restic/internal/backend/limiter"
 	"github.com/restic/restic/internal/backend/location"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/fs"
@@ -24,7 +25,7 @@ import (
 type Local struct {
 	Config
 	layout.Layout
-	backend.Modes
+	util.Modes
 }
 
 // ensure statically that *Local implements restic.Backend.
@@ -43,7 +44,7 @@ func open(ctx context.Context, cfg Config) (*Local, error) {
 	}
 
 	fi, err := fs.Stat(l.Filename(restic.Handle{Type: restic.ConfigFile}))
-	m := backend.DeriveModesFromFileInfo(fi, err)
+	m := util.DeriveModesFromFileInfo(fi, err)
 	debug.Log("using (%03O file, %03O dir) permissions", m.File, m.Dir)
 
 	return &Local{
@@ -210,7 +211,7 @@ var tempFile = os.CreateTemp // Overridden by test.
 // Load runs fn with a reader that yields the contents of the file at h at the
 // given offset.
 func (b *Local) Load(ctx context.Context, h restic.Handle, length int, offset int64, fn func(rd io.Reader) error) error {
-	return backend.DefaultLoad(ctx, h, length, offset, b.openReader, fn)
+	return util.DefaultLoad(ctx, h, length, offset, b.openReader, fn)
 }
 
 func (b *Local) openReader(_ context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {

internal/backend/mem/mem_backend.go

@@ -10,8 +10,8 @@ import (
 	"sync"
 
 	"github.com/cespare/xxhash/v2"
-	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/backend/location"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
@@ -113,7 +113,7 @@ func (be *MemoryBackend) Save(ctx context.Context, h restic.Handle, rd restic.Re
 // Load runs fn with a reader that yields the contents of the file at h at the
 // given offset.
 func (be *MemoryBackend) Load(ctx context.Context, h restic.Handle, length int, offset int64, fn func(rd io.Reader) error) error {
-	return backend.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
+	return util.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
 }
 
 func (be *MemoryBackend) openReader(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {

internal/backend/rclone/backend.go

@@ -21,6 +21,7 @@ import (
 	"github.com/restic/restic/internal/backend/limiter"
 	"github.com/restic/restic/internal/backend/location"
 	"github.com/restic/restic/internal/backend/rest"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"golang.org/x/net/http2"
@@ -81,7 +82,7 @@ func run(command string, args ...string) (*StdioConn, *sync.WaitGroup, chan stru
 	cmd.Stdin = r
 	cmd.Stdout = w
 
-	bg, err := backend.StartForeground(cmd)
+	bg, err := util.StartForeground(cmd)
 	// close rclone side of pipes
 	errR := r.Close()
 	errW := w.Close()
@@ -93,7 +94,7 @@ func run(command string, args ...string) (*StdioConn, *sync.WaitGroup, chan stru
 		err = errW
 	}
 	if err != nil {
-		if backend.IsErrDot(err) {
+		if util.IsErrDot(err) {
 			return nil, nil, nil, nil, errors.Errorf("cannot implicitly run relative executable %v found in current directory, use -o rclone.program=./<program> to override", cmd.Path)
 		}
 		return nil, nil, nil, nil, err

internal/backend/rest/rest.go

@@ -11,9 +11,9 @@ import (
 	"path"
 	"strings"
 
-	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/backend/layout"
 	"github.com/restic/restic/internal/backend/location"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
@@ -424,5 +424,5 @@ func (b *Backend) Close() error {
 
 // Delete removes all data in the backend.
 func (b *Backend) Delete(ctx context.Context) error {
-	return backend.DefaultDelete(ctx, b)
+	return util.DefaultDelete(ctx, b)
 }

internal/backend/s3/s3.go

@@ -11,9 +11,9 @@ import (
 	"strings"
 	"time"
 
-	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/backend/layout"
 	"github.com/restic/restic/internal/backend/location"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
@@ -298,7 +298,7 @@ func (be *Backend) Load(ctx context.Context, h restic.Handle, length int, offset
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	return backend.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
+	return util.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
 }
 
 func (be *Backend) openReader(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
@@ -424,7 +424,7 @@ func (be *Backend) List(ctx context.Context, t restic.FileType, fn func(restic.F
 
 // Delete removes all restic keys in the bucket. It will not remove the bucket itself.
 func (be *Backend) Delete(ctx context.Context) error {
-	return backend.DefaultDelete(ctx, be)
+	return util.DefaultDelete(ctx, be)
 }
 
 // Close does nothing

internal/backend/sftp/sftp.go

@@ -17,6 +17,7 @@ import (
 	"github.com/restic/restic/internal/backend/layout"
 	"github.com/restic/restic/internal/backend/limiter"
 	"github.com/restic/restic/internal/backend/location"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
@@ -38,7 +39,7 @@ type SFTP struct {
 
 	layout.Layout
 	Config
-	backend.Modes
+	util.Modes
 }
 
 var _ restic.Backend = &SFTP{}
@@ -83,9 +84,9 @@ func startClient(cfg Config) (*SFTP, error) {
 		return nil, errors.Wrap(err, "cmd.StdoutPipe")
 	}
 
-	bg, err := backend.StartForeground(cmd)
+	bg, err := util.StartForeground(cmd)
 	if err != nil {
-		if backend.IsErrDot(err) {
+		if util.IsErrDot(err) {
 			return nil, errors.Errorf("cannot implicitly run relative executable %v found in current directory, use -o sftp.command=./<command> to override", cmd.Path)
 		}
 		return nil, err
@@ -153,7 +154,7 @@ func open(ctx context.Context, sftp *SFTP, cfg Config) (*SFTP, error) {
 	debug.Log("layout: %v\n", sftp.Layout)
 
 	fi, err := sftp.c.Stat(sftp.Layout.Filename(restic.Handle{Type: restic.ConfigFile}))
-	m := backend.DeriveModesFromFileInfo(fi, err)
+	m := util.DeriveModesFromFileInfo(fi, err)
 	debug.Log("using (%03O file, %03O dir) permissions", m.File, m.Dir)
 
 	sftp.Config = cfg
@@ -259,7 +260,7 @@ func Create(ctx context.Context, cfg Config) (*SFTP, error) {
 		return nil, err
 	}
 
-	sftp.Modes = backend.DefaultModes
+	sftp.Modes = util.DefaultModes
 
 	// test if config file already exists
 	_, err = sftp.c.Lstat(sftp.Layout.Filename(restic.Handle{Type: restic.ConfigFile}))
@@ -414,7 +415,7 @@ func (r *SFTP) checkNoSpace(dir string, size int64, origErr error) error {
 // Load runs fn with a reader that yields the contents of the file at h at the
 // given offset.
 func (r *SFTP) Load(ctx context.Context, h restic.Handle, length int, offset int64, fn func(rd io.Reader) error) error {
-	return backend.DefaultLoad(ctx, h, length, offset, r.openReader, fn)
+	return util.DefaultLoad(ctx, h, length, offset, r.openReader, fn)
 }
 
 func (r *SFTP) openReader(_ context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {

internal/backend/swift/swift.go

@@ -13,9 +13,9 @@ import (
 	"strings"
 	"time"
 
-	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/backend/layout"
 	"github.com/restic/restic/internal/backend/location"
+	"github.com/restic/restic/internal/backend/util"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
@@ -135,7 +135,7 @@ func (be *beSwift) HasAtomicReplace() bool {
 // Load runs fn with a reader that yields the contents of the file at h at the
 // given offset.
 func (be *beSwift) Load(ctx context.Context, h restic.Handle, length int, offset int64, fn func(rd io.Reader) error) error {
-	return backend.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
+	return util.DefaultLoad(ctx, h, length, offset, be.openReader, fn)
 }
 
 func (be *beSwift) openReader(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
@@ -245,7 +245,7 @@ func (be *beSwift) IsNotExist(err error) bool {
 // Delete removes all restic objects in the container.
 // It will not remove the container itself.
 func (be *beSwift) Delete(ctx context.Context) error {
-	return backend.DefaultDelete(ctx, be)
+	return util.DefaultDelete(ctx, be)
 }
 
 // Close does nothing

internal/backend/util/defaults.go

@@ -0,0 +1,50 @@
+package util
+
+import (
+	"context"
+	"io"
+
+	"github.com/restic/restic/internal/restic"
+)
+
+// DefaultLoad implements Backend.Load using lower-level openReader func
+func DefaultLoad(ctx context.Context, h restic.Handle, length int, offset int64,
+	openReader func(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error),
+	fn func(rd io.Reader) error) error {
+
+	rd, err := openReader(ctx, h, length, offset)
+	if err != nil {
+		return err
+	}
+	err = fn(rd)
+	if err != nil {
+		_ = rd.Close() // ignore secondary errors closing the reader
+		return err
+	}
+	return rd.Close()
+}
+
+// DefaultDelete removes all restic keys in the bucket. It will not remove the bucket itself.
+func DefaultDelete(ctx context.Context, be restic.Backend) error {
+	alltypes := []restic.FileType{
+		restic.PackFile,
+		restic.KeyFile,
+		restic.LockFile,
+		restic.SnapshotFile,
+		restic.IndexFile}
+
+	for _, t := range alltypes {
+		err := be.List(ctx, t, func(fi restic.FileInfo) error {
+			return be.Remove(ctx, restic.Handle{Type: t, Name: fi.Name})
+		})
+		if err != nil {
+			return nil
+		}
+	}
+	err := be.Remove(ctx, restic.Handle{Type: restic.ConfigFile})
+	if err != nil && be.IsNotExist(err) {
+		err = nil
+	}
+
+	return err
+}

internal/backend/util/defaults_test.go

@@ -0,0 +1,64 @@
+package util_test
+
+import (
+	"context"
+	"io"
+	"testing"
+
+	"github.com/restic/restic/internal/backend/util"
+	"github.com/restic/restic/internal/errors"
+	"github.com/restic/restic/internal/restic"
+
+	rtest "github.com/restic/restic/internal/test"
+)
+
+type mockReader struct {
+	closed bool
+}
+
+func (rd *mockReader) Read(_ []byte) (n int, err error) {
+	return 0, nil
+}
+func (rd *mockReader) Close() error {
+	rd.closed = true
+	return nil
+}
+
+func TestDefaultLoad(t *testing.T) {
+
+	h := restic.Handle{Name: "id", Type: restic.PackFile}
+	rd := &mockReader{}
+
+	// happy case, assert correct parameters are passed around and content stream is closed
+	err := util.DefaultLoad(context.TODO(), h, 10, 11, func(ctx context.Context, ih restic.Handle, length int, offset int64) (io.ReadCloser, error) {
+		rtest.Equals(t, h, ih)
+		rtest.Equals(t, int(10), length)
+		rtest.Equals(t, int64(11), offset)
+
+		return rd, nil
+	}, func(ird io.Reader) error {
+		rtest.Equals(t, rd, ird)
+		return nil
+	})
+	rtest.OK(t, err)
+	rtest.Equals(t, true, rd.closed)
+
+	// unhappy case, assert producer errors are handled correctly
+	err = util.DefaultLoad(context.TODO(), h, 10, 11, func(ctx context.Context, ih restic.Handle, length int, offset int64) (io.ReadCloser, error) {
+		return nil, errors.Errorf("producer error")
+	}, func(ird io.Reader) error {
+		t.Fatalf("unexpected consumer invocation")
+		return nil
+	})
+	rtest.Equals(t, "producer error", err.Error())
+
+	// unhappy case, assert consumer errors are handled correctly
+	rd = &mockReader{}
+	err = util.DefaultLoad(context.TODO(), h, 10, 11, func(ctx context.Context, ih restic.Handle, length int, offset int64) (io.ReadCloser, error) {
+		return rd, nil
+	}, func(ird io.Reader) error {
+		return errors.Errorf("consumer error")
+	})
+	rtest.Equals(t, true, rd.closed)
+	rtest.Equals(t, "consumer error", err.Error())
+}

internal/backend/util/errdot_119.go

@@ -8,7 +8,7 @@
 // Once the minimum Go version restic supports is 1.19, remove this file and
 //  replace any calls to it with the corresponding code as per below.
 
-package backend
+package util
 
 import (
 	"errors"

internal/backend/util/errdot_old.go

@@ -6,7 +6,7 @@
 // Once the minimum Go version restic supports is 1.19, remove this file
 //  and perform the actions listed in errdot_119.go.
 
-package backend
+package util
 
 func IsErrDot(err error) bool {
 	return false

internal/backend/util/foreground.go

@@ -1,4 +1,4 @@
-package backend
+package util
 
 import (
 	"os"

internal/backend/util/foreground_sysv.go

@@ -1,7 +1,7 @@
 //go:build aix || solaris
 // +build aix solaris
 
-package backend
+package util
 
 import (
 	"os/exec"

internal/backend/util/foreground_test.go

@@ -1,7 +1,7 @@
 //go:build !windows
 // +build !windows
 
-package backend_test
+package util_test
 
 import (
 	"bufio"
@@ -10,7 +10,7 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/restic/restic/internal/backend"
+	"github.com/restic/restic/internal/backend/util"
 	rtest "github.com/restic/restic/internal/test"
 )
 
@@ -22,7 +22,7 @@ func TestForeground(t *testing.T) {
 	stdout, err := cmd.StdoutPipe()
 	rtest.OK(t, err)
 
-	bg, err := backend.StartForeground(cmd)
+	bg, err := util.StartForeground(cmd)
 	rtest.OK(t, err)
 	defer func() {
 		rtest.OK(t, cmd.Wait())

internal/backend/util/foreground_unix.go

@@ -1,7 +1,7 @@
 //go:build !aix && !solaris && !windows
 // +build !aix,!solaris,!windows
 
-package backend
+package util
 
 import (
 	"os"

internal/backend/util/foreground_windows.go

@@ -1,4 +1,4 @@
-package backend
+package util
 
 import (
 	"os/exec"

internal/backend/util/paths.go

@@ -1,4 +1,4 @@
-package backend
+package util
 
 import "os"
 

internal/backend/utils.go

@@ -58,48 +58,6 @@ func LimitReadCloser(r io.ReadCloser, n int64) *LimitedReadCloser {
 	return &LimitedReadCloser{Closer: r, LimitedReader: io.LimitedReader{R: r, N: n}}
 }
 
-// DefaultLoad implements Backend.Load using lower-level openReader func
-func DefaultLoad(ctx context.Context, h restic.Handle, length int, offset int64,
-	openReader func(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error),
-	fn func(rd io.Reader) error) error {
-
-	rd, err := openReader(ctx, h, length, offset)
-	if err != nil {
-		return err
-	}
-	err = fn(rd)
-	if err != nil {
-		_ = rd.Close() // ignore secondary errors closing the reader
-		return err
-	}
-	return rd.Close()
-}
-
-// DefaultDelete removes all restic keys in the bucket. It will not remove the bucket itself.
-func DefaultDelete(ctx context.Context, be restic.Backend) error {
-	alltypes := []restic.FileType{
-		restic.PackFile,
-		restic.KeyFile,
-		restic.LockFile,
-		restic.SnapshotFile,
-		restic.IndexFile}
-
-	for _, t := range alltypes {
-		err := be.List(ctx, t, func(fi restic.FileInfo) error {
-			return be.Remove(ctx, restic.Handle{Type: t, Name: fi.Name})
-		})
-		if err != nil {
-			return nil
-		}
-	}
-	err := be.Remove(ctx, restic.Handle{Type: restic.ConfigFile})
-	if err != nil && be.IsNotExist(err) {
-		err = nil
-	}
-
-	return err
-}
-
 type memorizedLister struct {
 	fileInfos []restic.FileInfo
 	tpe       restic.FileType

internal/backend/utils_test.go

@@ -11,7 +11,6 @@ import (
 	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/backend/mem"
 	"github.com/restic/restic/internal/backend/mock"
-	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
 	rtest "github.com/restic/restic/internal/test"
 )
@@ -150,57 +149,6 @@ func TestLoadAllAppend(t *testing.T) {
 	}
 }
 
-type mockReader struct {
-	closed bool
-}
-
-func (rd *mockReader) Read(_ []byte) (n int, err error) {
-	return 0, nil
-}
-func (rd *mockReader) Close() error {
-	rd.closed = true
-	return nil
-}
-
-func TestDefaultLoad(t *testing.T) {
-
-	h := restic.Handle{Name: "id", Type: restic.PackFile}
-	rd := &mockReader{}
-
-	// happy case, assert correct parameters are passed around and content stream is closed
-	err := backend.DefaultLoad(context.TODO(), h, 10, 11, func(ctx context.Context, ih restic.Handle, length int, offset int64) (io.ReadCloser, error) {
-		rtest.Equals(t, h, ih)
-		rtest.Equals(t, int(10), length)
-		rtest.Equals(t, int64(11), offset)
-
-		return rd, nil
-	}, func(ird io.Reader) error {
-		rtest.Equals(t, rd, ird)
-		return nil
-	})
-	rtest.OK(t, err)
-	rtest.Equals(t, true, rd.closed)
-
-	// unhappy case, assert producer errors are handled correctly
-	err = backend.DefaultLoad(context.TODO(), h, 10, 11, func(ctx context.Context, ih restic.Handle, length int, offset int64) (io.ReadCloser, error) {
-		return nil, errors.Errorf("producer error")
-	}, func(ird io.Reader) error {
-		t.Fatalf("unexpected consumer invocation")
-		return nil
-	})
-	rtest.Equals(t, "producer error", err.Error())
-
-	// unhappy case, assert consumer errors are handled correctly
-	rd = &mockReader{}
-	err = backend.DefaultLoad(context.TODO(), h, 10, 11, func(ctx context.Context, ih restic.Handle, length int, offset int64) (io.ReadCloser, error) {
-		return rd, nil
-	}, func(ird io.Reader) error {
-		return errors.Errorf("consumer error")
-	})
-	rtest.Equals(t, true, rd.closed)
-	rtest.Equals(t, "consumer error", err.Error())
-}
-
 func TestMemoizeList(t *testing.T) {
 	// setup backend to serve as data source for memoized list
 	be := mock.NewBackend()

internal/restic/backend.go

@@ -43,7 +43,7 @@ type Backend interface {
 	// The function fn may be called multiple times during the same Load invocation
 	// and therefore must be idempotent.
 	//
-	// Implementations are encouraged to use backend.DefaultLoad
+	// Implementations are encouraged to use util.DefaultLoad
 	Load(ctx context.Context, h Handle, length int, offset int64, fn func(rd io.Reader) error) error
 
 	// Stat returns information about the File identified by h.