refactor(tvix/nar-bridge): drop reader package r/6693

Make the import function usable on any reader.

Change-Id: I84d2004cb73cdd7a11fe8efb0f2efb6335d5e6b0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9527
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>

3 files changed, 0 insertions, 926 deletions

diff --git a/tvix/nar-bridge/pkg/reader/hashers.go b/tvix/nar-bridge/pkg/reader/hashers.go
deleted file mode 100644
index 7e98d2062d21..000000000000
--- a/tvix/nar-bridge/pkg/reader/hashers.go
+++ /dev/null
@@ -1,66 +0,0 @@
-package reader
-
-import (
-	"errors"
-	"fmt"
-	"hash"
-	"io"
-)
-
-var _ io.Reader = &Hasher{}
-
-// Hasher wraps io.Reader.
-// You can ask it for the digest of the hash function used internally, and the
-// number of bytes written.
-type Hasher struct {
-	r         io.Reader
-	h         hash.Hash
-	bytesRead uint32
-}
-
-func NewHasher(r io.Reader, h hash.Hash) *Hasher {
-	return &Hasher{
-		r:         r,
-		h:         h,
-		bytesRead: 0,
-	}
-}
-
-func (h *Hasher) Read(p []byte) (int, error) {
-	nRead, rdErr := h.r.Read(p)
-
-	// write the number of bytes read from the reader to the hash.
-	// We need to do this independently on whether there's been error.
-	// n always describes the number of successfully written bytes.
-	nHash, hashErr := h.h.Write(p[0:nRead])
-	if hashErr != nil {
-		return nRead, fmt.Errorf("unable to write to hash: %w", hashErr)
-	}
-
-	// We assume here the hash function accepts the whole p in one Go,
-	// and doesn't early-return on the Write.
-	// We compare it with nRead and bail out if that was not the case.
-	if nHash != nRead {
-		return nRead, fmt.Errorf("hash didn't accept the full write")
-	}
-
-	// update bytesWritten
-	h.bytesRead += uint32(nRead)
-
-	if rdErr != nil {
-		if errors.Is(rdErr, io.EOF) {
-			return nRead, rdErr
-		}
-		return nRead, fmt.Errorf("error from underlying reader: %w", rdErr)
-	}
-
-	return nRead, hashErr
-}
-
-func (h *Hasher) BytesWritten() uint32 {
-	return h.bytesRead
-}
-
-func (h *Hasher) Sum(b []byte) []byte {
-	return h.h.Sum(b)
-}
diff --git a/tvix/nar-bridge/pkg/reader/reader.go b/tvix/nar-bridge/pkg/reader/reader.go
deleted file mode 100644
index 08fdd39a7f06..000000000000
--- a/tvix/nar-bridge/pkg/reader/reader.go
+++ /dev/null
@@ -1,263 +0,0 @@
-package reader
-
-import (
-	"context"
-	"crypto/sha256"
-	"errors"
-	"fmt"
-	"io"
-	"path"
-	"strings"
-
-	castorev1pb "code.tvl.fyi/tvix/castore/protos"
-	storev1pb "code.tvl.fyi/tvix/store/protos"
-	"github.com/nix-community/go-nix/pkg/nar"
-	"lukechampine.com/blake3"
-)
-
-type Reader struct {
-	hrSha256 *Hasher
-}
-
-// An item on the directories stack
-type stackItem struct {
-	path      string
-	directory *castorev1pb.Directory
-}
-
-func New(r io.Reader) *Reader {
-	// Instead of using the underlying reader itself, wrap the reader
-	// with a hasher calculating sha256 and one calculating sha512,
-	// and feed that one into the NAR reader.
-	hrSha256 := NewHasher(r, sha256.New())
-
-	return &Reader{
-		hrSha256: hrSha256,
-	}
-}
-
-// Import reads from the internally-wrapped reader,
-// and calls the callback functions whenever regular file contents are
-// encountered, or a Directory node is about to be finished.
-func (r *Reader) Import(
-	ctx context.Context,
-	// callback function called with each regular file content
-	blobCb func(fileReader io.Reader) error,
-	// callback function called with each finalized directory node
-	directoryCb func(directory *castorev1pb.Directory) error,
-) (*storev1pb.PathInfo, error) {
-
-	// construct a NAR reader, by reading through hrSha256
-	narReader, err := nar.NewReader(r.hrSha256)
-	if err != nil {
-		return nil, fmt.Errorf("failed to instantiate nar reader: %w", err)
-	}
-	defer narReader.Close()
-
-	// If we store a symlink or regular file at the root, these are not nil.
-	// If they are nil, we instead have a stackDirectory.
-	var rootSymlink *castorev1pb.SymlinkNode
-	var rootFile *castorev1pb.FileNode
-	var stackDirectory *castorev1pb.Directory
-
-	var stack = []stackItem{}
-
-	// popFromStack is used when we transition to a different directory or
-	// drain the stack when we reach the end of the NAR.
-	// It adds the popped element to the element underneath if any,
-	// and passes it to the directoryCb callback.
-	// This function may only be called if the stack is not already empty.
-	popFromStack := func() error {
-		// Keep the top item, and "resize" the stack slice.
-		// This will only make the last element unaccessible, but chances are high
-		// we're re-using that space anyways.
-		toPop := stack[len(stack)-1]
-		stack = stack[:len(stack)-1]
-
-		// if there's still a parent left on the stack, refer to it from there.
-		if len(stack) > 0 {
-			dgst, err := toPop.directory.Digest()
-			if err != nil {
-				return fmt.Errorf("unable to calculate directory digest: %w", err)
-			}
-
-			topOfStack := stack[len(stack)-1].directory
-			topOfStack.Directories = append(topOfStack.Directories, &castorev1pb.DirectoryNode{
-				Name:   []byte(path.Base(toPop.path)),
-				Digest: dgst,
-				Size:   toPop.directory.Size(),
-			})
-		}
-		// call the directoryCb
-		if err := directoryCb(toPop.directory); err != nil {
-			return fmt.Errorf("failed calling directoryCb: %w", err)
-		}
-		// Keep track that we have encounter at least one directory
-		stackDirectory = toPop.directory
-		return nil
-	}
-
-	getBasename := func(p string) string {
-		// extract the basename. In case of "/", replace with empty string.
-		basename := path.Base(p)
-		if basename == "/" {
-			basename = ""
-		}
-		return basename
-	}
-
-	for {
-		select {
-		case <-ctx.Done():
-			return nil, ctx.Err()
-		default:
-			// call narReader.Next() to get the next element
-			hdr, err := narReader.Next()
-
-			// If this returns an error, it's either EOF (when we're done reading from the NAR),
-			// or another error
-			if err != nil {
-				// if this returns no EOF, bail out
-				if !errors.Is(err, io.EOF) {
-					return nil, fmt.Errorf("failed getting next nar element: %w", err)
-				}
-
-				// The NAR has been read all the way to the end…
-				// Make sure we close the nar reader, which might read some final trailers.
-				if err := narReader.Close(); err != nil {
-					return nil, fmt.Errorf("unable to close nar reader: %w", err)
-				}
-
-				// Check the stack. While it's not empty, we need to pop things off the stack.
-				for len(stack) > 0 {
-					err := popFromStack()
-					if err != nil {
-						return nil, fmt.Errorf("unable to pop from stack: %w", err)
-					}
-
-				}
-
-				// Stack is empty. We now either have a regular or symlink root node,
-				// or we encountered at least one directory assemble pathInfo with these and
-				// return.
-				pi := &storev1pb.PathInfo{
-					Node:       nil,
-					References: [][]byte{},
-					Narinfo: &storev1pb.NARInfo{
-						NarSize:        uint64(r.hrSha256.BytesWritten()),
-						NarSha256:      r.hrSha256.Sum(nil),
-						Signatures:     []*storev1pb.NARInfo_Signature{},
-						ReferenceNames: []string{},
-					},
-				}
-
-				if rootFile != nil {
-					pi.Node = &castorev1pb.Node{
-						Node: &castorev1pb.Node_File{
-							File: rootFile,
-						},
-					}
-				}
-				if rootSymlink != nil {
-					pi.Node = &castorev1pb.Node{
-						Node: &castorev1pb.Node_Symlink{
-							Symlink: rootSymlink,
-						},
-					}
-				}
-				if stackDirectory != nil {
-					// calculate directory digest (i.e. after we received all its contents)
-					dgst, err := stackDirectory.Digest()
-					if err != nil {
-						return nil, fmt.Errorf("unable to calculate root directory digest: %w", err)
-					}
-
-					pi.Node = &castorev1pb.Node{
-						Node: &castorev1pb.Node_Directory{
-							Directory: &castorev1pb.DirectoryNode{
-								Name:   []byte{},
-								Digest: dgst,
-								Size:   stackDirectory.Size(),
-							},
-						},
-					}
-				}
-				return pi, nil
-			}
-
-			// Check for valid path transitions, pop from stack if needed
-			// The nar reader already gives us some guarantees about ordering and illegal transitions,
-			// So we really only need to check if the top-of-stack path is a prefix of the path,
-			// and if it's not, pop from the stack. We do this repeatedly until the top of the stack is
-			// the subdirectory the new entry is in, or we hit the root directory.
-
-			// We don't need to worry about the root node case, because we can only finish the root "/"
-			// If we're at the end of the NAR reader (covered by the EOF check)
-			for len(stack) > 1 && !strings.HasPrefix(hdr.Path, stack[len(stack)-1].path+"/") {
-				err := popFromStack()
-				if err != nil {
-					return nil, fmt.Errorf("unable to pop from stack: %w", err)
-				}
-			}
-
-			if hdr.Type == nar.TypeSymlink {
-				symlinkNode := &castorev1pb.SymlinkNode{
-					Name:   []byte(getBasename(hdr.Path)),
-					Target: []byte(hdr.LinkTarget),
-				}
-				if len(stack) > 0 {
-					topOfStack := stack[len(stack)-1].directory
-					topOfStack.Symlinks = append(topOfStack.Symlinks, symlinkNode)
-				} else {
-					rootSymlink = symlinkNode
-				}
-
-			}
-			if hdr.Type == nar.TypeRegular {
-				// wrap reader with a reader calculating the blake3 hash
-				fileReader := NewHasher(narReader, blake3.New(32, nil))
-
-				err := blobCb(fileReader)
-				if err != nil {
-					return nil, fmt.Errorf("failure from blobCb: %w", err)
-				}
-
-				// drive the file reader to the end, in case the CB function doesn't read
-				// all the way to the end on its own
-				if fileReader.BytesWritten() != uint32(hdr.Size) {
-					_, err := io.ReadAll(fileReader)
-					if err != nil {
-						return nil, fmt.Errorf("unable to read until the end of the file content: %w", err)
-					}
-				}
-
-				// read the blake3 hash
-				dgst := fileReader.Sum(nil)
-
-				fileNode := &castorev1pb.FileNode{
-					Name:       []byte(getBasename(hdr.Path)),
-					Digest:     dgst,
-					Size:       uint32(hdr.Size),
-					Executable: hdr.Executable,
-				}
-				if len(stack) > 0 {
-					topOfStack := stack[len(stack)-1].directory
-					topOfStack.Files = append(topOfStack.Files, fileNode)
-				} else {
-					rootFile = fileNode
-				}
-			}
-			if hdr.Type == nar.TypeDirectory {
-				directory := &castorev1pb.Directory{
-					Directories: []*castorev1pb.DirectoryNode{},
-					Files:       []*castorev1pb.FileNode{},
-					Symlinks:    []*castorev1pb.SymlinkNode{},
-				}
-				stack = append(stack, stackItem{
-					directory: directory,
-					path:      hdr.Path,
-				})
-			}
-		}
-	}
-}
diff --git a/tvix/nar-bridge/pkg/reader/reader_test.go b/tvix/nar-bridge/pkg/reader/reader_test.go
deleted file mode 100644
index 560b06ebdd4e..000000000000
--- a/tvix/nar-bridge/pkg/reader/reader_test.go
+++ /dev/null
@@ -1,597 +0,0 @@
-package reader_test
-
-import (
-	"context"
-	"errors"
-	"io"
-	"os"
-	"testing"
-
-	castorev1pb "code.tvl.fyi/tvix/castore/protos"
-	"code.tvl.fyi/tvix/nar-bridge/pkg/reader"
-	storev1pb "code.tvl.fyi/tvix/store/protos"
-	"github.com/google/go-cmp/cmp"
-	"github.com/stretchr/testify/require"
-	"google.golang.org/protobuf/testing/protocmp"
-)
-
-func requireProtoEq(t *testing.T, expected interface{}, actual interface{}) {
-	if diff := cmp.Diff(expected, actual, protocmp.Transform()); diff != "" {
-		t.Errorf("unexpected difference:\n%v", diff)
-	}
-}
-
-func mustDigest(d *castorev1pb.Directory) []byte {
-	dgst, err := d.Digest()
-	if err != nil {
-		panic(err)
-	}
-	return dgst
-}
-
-func TestSymlink(t *testing.T) {
-	f, err := os.Open("../../testdata/symlink.nar")
-	require.NoError(t, err)
-
-	r := reader.New(f)
-
-	actualPathInfo, err := r.Import(
-		context.Background(),
-		func(fileReader io.Reader) error {
-			panic("no file contents expected!")
-		}, func(directory *castorev1pb.Directory) error {
-			panic("no directories expected!")
-		},
-	)
-	require.NoError(t, err)
-
-	expectedPathInfo := &storev1pb.PathInfo{
-		Node: &castorev1pb.Node{
-			Node: &castorev1pb.Node_Symlink{
-				Symlink: &castorev1pb.SymlinkNode{
-					Name:   []byte(""),
-					Target: []byte("/nix/store/somewhereelse"),
-				},
-			},
-		},
-		References: [][]byte{},
-		Narinfo: &storev1pb.NARInfo{
-			NarSize: 136,
-			NarSha256: []byte{
-				0x09, 0x7d, 0x39, 0x7e, 0x9b, 0x58, 0x26, 0x38, 0x4e, 0xaa, 0x16, 0xc4, 0x57, 0x71, 0x5d, 0x1c, 0x1a, 0x51, 0x67, 0x03, 0x13, 0xea, 0xd0, 0xf5, 0x85, 0x66, 0xe0, 0xb2, 0x32, 0x53, 0x9c, 0xf1,
-			},
-			Signatures:     []*storev1pb.NARInfo_Signature{},
-			ReferenceNames: []string{},
-		},
-	}
-
-	requireProtoEq(t, expectedPathInfo, actualPathInfo)
-}
-
-func TestRegular(t *testing.T) {
-	f, err := os.Open("../../testdata/onebyteregular.nar")
-	require.NoError(t, err)
-
-	r := reader.New(f)
-
-	actualPathInfo, err := r.Import(
-		context.Background(),
-		func(fileReader io.Reader) error {
-			contents, err := io.ReadAll(fileReader)
-			require.NoError(t, err, "reading fileReader should not error")
-			require.Equal(t, []byte{0x01}, contents, "contents read from fileReader should match expectations")
-			return nil
-		}, func(directory *castorev1pb.Directory) error {
-			panic("no directories expected!")
-		},
-	)
-	require.NoError(t, err)
-
-	// The blake3 digest of the 0x01 byte.
-	BLAKE3_DIGEST_0X01 := []byte{
-		0x48, 0xfc, 0x72, 0x1f, 0xbb, 0xc1, 0x72, 0xe0, 0x92, 0x5f, 0xa2, 0x7a, 0xf1, 0x67, 0x1d,
-		0xe2, 0x25, 0xba, 0x92, 0x71, 0x34, 0x80, 0x29, 0x98, 0xb1, 0x0a, 0x15, 0x68, 0xa1, 0x88,
-		0x65, 0x2b,
-	}
-
-	expectedPathInfo := &storev1pb.PathInfo{
-		Node: &castorev1pb.Node{
-			Node: &castorev1pb.Node_File{
-				File: &castorev1pb.FileNode{
-					Name:       []byte(""),
-					Digest:     BLAKE3_DIGEST_0X01,
-					Size:       1,
-					Executable: false,
-				},
-			},
-		},
-		References: [][]byte{},
-		Narinfo: &storev1pb.NARInfo{
-			NarSize: 120,
-			NarSha256: []byte{
-				0x73, 0x08, 0x50, 0xa8, 0x11, 0x25, 0x9d, 0xbf, 0x3a, 0x68, 0xdc, 0x2e, 0xe8, 0x7a, 0x79, 0xaa, 0x6c, 0xae, 0x9f, 0x71, 0x37, 0x5e, 0xdf, 0x39, 0x6f, 0x9d, 0x7a, 0x91, 0xfb, 0xe9, 0x13, 0x4d,
-			},
-			Signatures:     []*storev1pb.NARInfo_Signature{},
-			ReferenceNames: []string{},
-		},
-	}
-
-	requireProtoEq(t, expectedPathInfo, actualPathInfo)
-}
-
-func TestEmptyDirectory(t *testing.T) {
-	f, err := os.Open("../../testdata/emptydirectory.nar")
-	require.NoError(t, err)
-
-	r := reader.New(f)
-
-	expectedDirectory := &castorev1pb.Directory{
-		Directories: []*castorev1pb.DirectoryNode{},
-		Files:       []*castorev1pb.FileNode{},
-		Symlinks:    []*castorev1pb.SymlinkNode{},
-	}
-	actualPathInfo, err := r.Import(
-		context.Background(),
-		func(fileReader io.Reader) error {
-			panic("no file contents expected!")
-		}, func(directory *castorev1pb.Directory) error {
-			requireProtoEq(t, expectedDirectory, directory)
-			return nil
-		},
-	)
-	require.NoError(t, err)
-
-	expectedPathInfo := &storev1pb.PathInfo{
-		Node: &castorev1pb.Node{
-			Node: &castorev1pb.Node_Directory{
-				Directory: &castorev1pb.DirectoryNode{
-					Name:   []byte(""),
-					Digest: mustDigest(expectedDirectory),
-					Size:   expectedDirectory.Size(),
-				},
-			},
-		},
-		References: [][]byte{},
-		Narinfo: &storev1pb.NARInfo{
-			NarSize: 96,
-			NarSha256: []byte{
-				0xa5, 0x0a, 0x5a, 0xb6, 0xd9, 0x92, 0xf5, 0x59, 0x8e, 0xdd, 0x92, 0x10, 0x50, 0x59, 0xfa, 0xe9, 0xac, 0xfc, 0x19, 0x29, 0x81, 0xe0, 0x8b, 0xd8, 0x85, 0x34, 0xc2, 0x16, 0x7e, 0x92, 0x52, 0x6a,
-			},
-			Signatures:     []*storev1pb.NARInfo_Signature{},
-			ReferenceNames: []string{},
-		},
-	}
-	requireProtoEq(t, expectedPathInfo, actualPathInfo)
-}
-
-func TestFull(t *testing.T) {
-	f, err := os.Open("../../testdata/nar_1094wph9z4nwlgvsd53abfz8i117ykiv5dwnq9nnhz846s7xqd7d.nar")
-	require.NoError(t, err)
-
-	r := reader.New(f)
-
-	expectedDirectoryPaths := []string{
-		"/bin",
-		"/share/man/man1",
-		"/share/man/man5",
-		"/share/man/man8",
-		"/share/man",
-		"/share",
-		"/",
-	}
-	expectedDirectories := make(map[string]*castorev1pb.Directory, len(expectedDirectoryPaths))
-
-	// /bin is a leaf directory
-	expectedDirectories["/bin"] = &castorev1pb.Directory{
-		Directories: []*castorev1pb.DirectoryNode{},
-		Files: []*castorev1pb.FileNode{
-			{
-				Name: []byte("arp"),
-				Digest: []byte{
-					0xfb, 0xc4, 0x61, 0x4a, 0x29, 0x27, 0x11, 0xcb, 0xcc, 0xe4, 0x99, 0x81, 0x9c, 0xf0, 0xa9, 0x17, 0xf7, 0xd0, 0x91, 0xbe, 0xea, 0x08, 0xcb, 0x5b, 0xaa, 0x76, 0x76, 0xf5, 0xee, 0x4f, 0x82, 0xbb,
-				},
-				Size:       55288,
-				Executable: true,
-			},
-			{
-				Name: []byte("hostname"),
-				Digest: []byte{
-					0x9c, 0x6a, 0xe4, 0xb5, 0xe4, 0x6c, 0xb5, 0x67, 0x45, 0x0e, 0xaa, 0x2a, 0xd8, 0xdd, 0x9b, 0x38, 0xd7, 0xed, 0x01, 0x02, 0x84, 0xf7, 0x26, 0xe1, 0xc7, 0xf3, 0x1c, 0xeb, 0xaa, 0x8a, 0x01, 0x30,
-				},
-				Size:       17704,
-				Executable: true,
-			},
-			{
-				Name: []byte("ifconfig"),
-				Digest: []byte{
-					0x25, 0xbe, 0x3b, 0x1d, 0xf4, 0x1a, 0x45, 0x42, 0x79, 0x09, 0x2c, 0x2a, 0x83, 0xf0, 0x0b, 0xff, 0xe8, 0xc0, 0x9c, 0x26, 0x98, 0x70, 0x15, 0x4d, 0xa8, 0xca, 0x05, 0xfe, 0x92, 0x68, 0x35, 0x2e,
-				},
-				Size:       72576,
-				Executable: true,
-			},
-			{
-				Name: []byte("nameif"),
-				Digest: []byte{
-					0x8e, 0xaa, 0xc5, 0xdb, 0x71, 0x08, 0x8e, 0xe5, 0xe6, 0x30, 0x1f, 0x2c, 0x3a, 0xf2, 0x42, 0x39, 0x0c, 0x57, 0x15, 0xaf, 0x50, 0xaa, 0x1c, 0xdf, 0x84, 0x22, 0x08, 0x77, 0x03, 0x54, 0x62, 0xb1,
-				},
-				Size:       18776,
-				Executable: true,
-			},
-			{
-				Name: []byte("netstat"),
-				Digest: []byte{
-					0x13, 0x34, 0x7e, 0xdd, 0x2a, 0x9a, 0x17, 0x0b, 0x3f, 0xc7, 0x0a, 0xe4, 0x92, 0x89, 0x25, 0x9f, 0xaa, 0xb5, 0x05, 0x6b, 0x24, 0xa7, 0x91, 0xeb, 0xaf, 0xf9, 0xe9, 0x35, 0x56, 0xaa, 0x2f, 0xb2,
-				},
-				Size:       131784,
-				Executable: true,
-			},
-			{
-				Name: []byte("plipconfig"),
-				Digest: []byte{
-					0x19, 0x7c, 0x80, 0xdc, 0x81, 0xdc, 0xb4, 0xc0, 0x45, 0xe1, 0xf9, 0x76, 0x51, 0x4f, 0x50, 0xbf, 0xa4, 0x69, 0x51, 0x9a, 0xd4, 0xa9, 0xe7, 0xaa, 0xe7, 0x0d, 0x53, 0x32, 0xff, 0x28, 0x40, 0x60,
-				},
-				Size:       13160,
-				Executable: true,
-			},
-			{
-				Name: []byte("rarp"),
-				Digest: []byte{
-					0x08, 0x85, 0xb4, 0x85, 0x03, 0x2b, 0x3c, 0x7a, 0x3e, 0x24, 0x4c, 0xf8, 0xcc, 0x45, 0x01, 0x9e, 0x79, 0x43, 0x8c, 0x6f, 0x5e, 0x32, 0x46, 0x54, 0xb6, 0x68, 0x91, 0x8e, 0xa0, 0xcb, 0x6e, 0x0d,
-				},
-				Size:       30384,
-				Executable: true,
-			},
-			{
-				Name: []byte("route"),
-				Digest: []byte{
-					0x4d, 0x14, 0x20, 0x89, 0x9e, 0x76, 0xf4, 0xe2, 0x92, 0x53, 0xee, 0x9b, 0x78, 0x7d, 0x23, 0x80, 0x6c, 0xff, 0xe6, 0x33, 0xdc, 0x4a, 0x10, 0x29, 0x39, 0x02, 0xa0, 0x60, 0xff, 0xe2, 0xbb, 0xd7,
-				},
-				Size:       61928,
-				Executable: true,
-			},
-			{
-				Name: []byte("slattach"),
-				Digest: []byte{
-					0xfb, 0x25, 0xc3, 0x73, 0xb7, 0xb1, 0x0b, 0x25, 0xcd, 0x7b, 0x62, 0xf6, 0x71, 0x83, 0xfe, 0x36, 0x80, 0xf6, 0x48, 0xc3, 0xdb, 0xd8, 0x0c, 0xfe, 0xb8, 0xd3, 0xda, 0x32, 0x9b, 0x47, 0x4b, 0x05,
-				},
-				Size:       35672,
-				Executable: true,
-			},
-		},
-		Symlinks: []*castorev1pb.SymlinkNode{
-			{
-				Name:   []byte("dnsdomainname"),
-				Target: []byte("hostname"),
-			},
-			{
-				Name:   []byte("domainname"),
-				Target: []byte("hostname"),
-			},
-			{
-				Name:   []byte("nisdomainname"),
-				Target: []byte("hostname"),
-			},
-			{
-				Name:   []byte("ypdomainname"),
-				Target: []byte("hostname"),
-			},
-		},
-	}
-
-	// /share/man/man1 is a leaf directory.
-	// The parser traversed over /sbin, but only added it to / which is still on the stack.
-	expectedDirectories["/share/man/man1"] = &castorev1pb.Directory{
-		Directories: []*castorev1pb.DirectoryNode{},
-		Files: []*castorev1pb.FileNode{
-			{
-				Name: []byte("dnsdomainname.1.gz"),
-				Digest: []byte{
-					0x98, 0x8a, 0xbd, 0xfa, 0x64, 0xd5, 0xb9, 0x27, 0xfe, 0x37, 0x43, 0x56, 0xb3, 0x18, 0xc7, 0x2b, 0xcb, 0xe3, 0x17, 0x1c, 0x17, 0xf4, 0x17, 0xeb, 0x4a, 0xa4, 0x99, 0x64, 0x39, 0xca, 0x2d, 0xee,
-				},
-				Size:       40,
-				Executable: false,
-			},
-			{
-				Name: []byte("domainname.1.gz"),
-				Digest: []byte{
-					0x98, 0x8a, 0xbd, 0xfa, 0x64, 0xd5, 0xb9, 0x27, 0xfe, 0x37, 0x43, 0x56, 0xb3, 0x18, 0xc7, 0x2b, 0xcb, 0xe3, 0x17, 0x1c, 0x17, 0xf4, 0x17, 0xeb, 0x4a, 0xa4, 0x99, 0x64, 0x39, 0xca, 0x2d, 0xee,
-				},
-				Size:       40,
-				Executable: false,
-			},
-			{
-				Name: []byte("hostname.1.gz"),
-				Digest: []byte{
-					0xbf, 0x89, 0xe6, 0x28, 0x00, 0x24, 0x66, 0x79, 0x70, 0x04, 0x38, 0xd6, 0xdd, 0x9d, 0xf6, 0x0e, 0x0d, 0xee, 0x00, 0xf7, 0x64, 0x4f, 0x05, 0x08, 0x9d, 0xf0, 0x36, 0xde, 0x85, 0xf4, 0x75, 0xdb,
-				},
-				Size:       1660,
-				Executable: false,
-			},
-			{
-				Name: []byte("nisdomainname.1.gz"),
-				Digest: []byte{
-					0x98, 0x8a, 0xbd, 0xfa, 0x64, 0xd5, 0xb9, 0x27, 0xfe, 0x37, 0x43, 0x56, 0xb3, 0x18, 0xc7, 0x2b, 0xcb, 0xe3, 0x17, 0x1c, 0x17, 0xf4, 0x17, 0xeb, 0x4a, 0xa4, 0x99, 0x64, 0x39, 0xca, 0x2d, 0xee,
-				},
-				Size:       40,
-				Executable: false,
-			},
-			{
-				Name: []byte("ypdomainname.1.gz"),
-				Digest: []byte{
-					0x98, 0x8a, 0xbd, 0xfa, 0x64, 0xd5, 0xb9, 0x27, 0xfe, 0x37, 0x43, 0x56, 0xb3, 0x18, 0xc7, 0x2b, 0xcb, 0xe3, 0x17, 0x1c, 0x17, 0xf4, 0x17, 0xeb, 0x4a, 0xa4, 0x99, 0x64, 0x39, 0xca, 0x2d, 0xee,
-				},
-				Size:       40,
-				Executable: false,
-			},
-		},
-		Symlinks: []*castorev1pb.SymlinkNode{},
-	}
-
-	// /share/man/man5 is a leaf directory
-	expectedDirectories["/share/man/man5"] = &castorev1pb.Directory{
-		Directories: []*castorev1pb.DirectoryNode{},
-		Files: []*castorev1pb.FileNode{
-			{
-				Name: []byte("ethers.5.gz"),
-				Digest: []byte{
-					0x42, 0x63, 0x8c, 0xc4, 0x18, 0x93, 0xcf, 0x60, 0xd6, 0xff, 0x43, 0xbc, 0x16, 0xb4, 0xfd, 0x22, 0xd2, 0xf2, 0x05, 0x0b, 0x52, 0xdc, 0x6a, 0x6b, 0xff, 0x34, 0xe2, 0x6a, 0x38, 0x3a, 0x07, 0xe3,
-				},
-				Size:       563,
-				Executable: false,
-			},
-		},
-		Symlinks: []*castorev1pb.SymlinkNode{},
-	}
-
-	// /share/man/man8 is a leaf directory
-	expectedDirectories["/share/man/man8"] = &castorev1pb.Directory{
-		Directories: []*castorev1pb.DirectoryNode{},
-		Files: []*castorev1pb.FileNode{
-			{
-				Name: []byte("arp.8.gz"),
-				Digest: []byte{
-					0xf5, 0x35, 0x4e, 0xf5, 0xf6, 0x44, 0xf7, 0x52, 0x0f, 0x42, 0xa0, 0x26, 0x51, 0xd9, 0x89, 0xf9, 0x68, 0xf2, 0xef, 0xeb, 0xba, 0xe1, 0xf4, 0x55, 0x01, 0x57, 0x77, 0xb7, 0x68, 0x55, 0x92, 0xef,
-				},
-				Size:       2464,
-				Executable: false,
-			},
-			{
-				Name: []byte("ifconfig.8.gz"),
-				Digest: []byte{
-					0x18, 0x65, 0x25, 0x11, 0x32, 0xee, 0x77, 0x91, 0x35, 0x4c, 0x3c, 0x24, 0xdb, 0xaf, 0x66, 0xdb, 0xfc, 0x17, 0x7b, 0xba, 0xe1, 0x3d, 0x05, 0xd2, 0xca, 0x6e, 0x2c, 0xe4, 0xef, 0xb8, 0xa8, 0xbe,
-				},
-				Size:       3382,
-				Executable: false,
-			},
-			{
-				Name: []byte("nameif.8.gz"),
-				Digest: []byte{
-					0x73, 0xc1, 0x27, 0xe8, 0x3b, 0xa8, 0x49, 0xdc, 0x0e, 0xdf, 0x70, 0x5f, 0xaf, 0x06, 0x01, 0x2c, 0x62, 0xe9, 0x18, 0x67, 0x01, 0x94, 0x64, 0x26, 0xca, 0x95, 0x22, 0xc0, 0xdc, 0xe4, 0x42, 0xb6,
-				},
-				Size:       523,
-				Executable: false,
-			},
-			{
-				Name: []byte("netstat.8.gz"),
-				Digest: []byte{
-					0xc0, 0x86, 0x43, 0x4a, 0x43, 0x57, 0xaa, 0x84, 0xa7, 0x24, 0xa0, 0x7c, 0x65, 0x38, 0x46, 0x1c, 0xf2, 0x45, 0xa2, 0xef, 0x12, 0x44, 0x18, 0xba, 0x52, 0x56, 0xe9, 0x8e, 0x6a, 0x0f, 0x70, 0x63,
-				},
-				Size:       4284,
-				Executable: false,
-			},
-			{
-				Name: []byte("plipconfig.8.gz"),
-				Digest: []byte{
-					0x2a, 0xd9, 0x1d, 0xa8, 0x9e, 0x0d, 0x05, 0xd0, 0xb0, 0x49, 0xaa, 0x64, 0xba, 0x29, 0x28, 0xc6, 0x45, 0xe1, 0xbb, 0x5e, 0x72, 0x8d, 0x48, 0x7b, 0x09, 0x4f, 0x0a, 0x82, 0x1e, 0x26, 0x83, 0xab,
-				},
-				Size:       889,
-				Executable: false,
-			},
-			{
-				Name: []byte("rarp.8.gz"),
-				Digest: []byte{
-					0x3d, 0x51, 0xc1, 0xd0, 0x6a, 0x59, 0x1e, 0x6d, 0x9a, 0xf5, 0x06, 0xd2, 0xe7, 0x7d, 0x7d, 0xd0, 0x70, 0x3d, 0x84, 0x64, 0xc3, 0x7d, 0xfb, 0x10, 0x84, 0x3b, 0xe1, 0xa9, 0xdf, 0x46, 0xee, 0x9f,
-				},
-				Size:       1198,
-				Executable: false,
-			},
-			{
-				Name: []byte("route.8.gz"),
-				Digest: []byte{
-					0x2a, 0x5a, 0x4b, 0x4f, 0x91, 0xf2, 0x78, 0xe4, 0xa9, 0x25, 0xb2, 0x7f, 0xa7, 0x2a, 0xc0, 0x8a, 0x4a, 0x65, 0xc9, 0x5f, 0x07, 0xa0, 0x48, 0x44, 0xeb, 0x46, 0xf9, 0xc9, 0xe1, 0x17, 0x96, 0x21,
-				},
-				Size:       3525,
-				Executable: false,
-			},
-			{
-				Name: []byte("slattach.8.gz"),
-				Digest: []byte{
-					0x3f, 0x05, 0x6b, 0x20, 0xe1, 0xe4, 0xf0, 0xba, 0x16, 0x15, 0x66, 0x6b, 0x57, 0x96, 0xe9, 0x9d, 0x83, 0xa8, 0x20, 0xaf, 0x8a, 0xca, 0x16, 0x4d, 0xa2, 0x6d, 0x94, 0x8e, 0xca, 0x91, 0x8f, 0xd4,
-				},
-				Size:       1441,
-				Executable: false,
-			},
-		},
-		Symlinks: []*castorev1pb.SymlinkNode{},
-	}
-
-	// /share/man holds /share/man/man{1,5,8}.
-	expectedDirectories["/share/man"] = &castorev1pb.Directory{
-		Directories: []*castorev1pb.DirectoryNode{
-			{
-				Name:   []byte("man1"),
-				Digest: mustDigest(expectedDirectories["/share/man/man1"]),
-				Size:   expectedDirectories["/share/man/man1"].Size(),
-			},
-			{
-				Name:   []byte("man5"),
-				Digest: mustDigest(expectedDirectories["/share/man/man5"]),
-				Size:   expectedDirectories["/share/man/man5"].Size(),
-			},
-			{
-				Name:   []byte("man8"),
-				Digest: mustDigest(expectedDirectories["/share/man/man8"]),
-				Size:   expectedDirectories["/share/man/man8"].Size(),
-			},
-		},
-		Files:    []*castorev1pb.FileNode{},
-		Symlinks: []*castorev1pb.SymlinkNode{},
-	}
-
-	// /share holds /share/man.
-	expectedDirectories["/share"] = &castorev1pb.Directory{
-		Directories: []*castorev1pb.DirectoryNode{
-			{
-				Name:   []byte("man"),
-				Digest: mustDigest(expectedDirectories["/share/man"]),
-				Size:   expectedDirectories["/share/man"].Size(),
-			},
-		},
-		Files:    []*castorev1pb.FileNode{},
-		Symlinks: []*castorev1pb.SymlinkNode{},
-	}
-
-	// / holds /bin, /share, and a /sbin symlink.
-	expectedDirectories["/"] = &castorev1pb.Directory{
-		Directories: []*castorev1pb.DirectoryNode{
-			{
-				Name:   []byte("bin"),
-				Digest: mustDigest(expectedDirectories["/bin"]),
-				Size:   expectedDirectories["/bin"].Size(),
-			},
-			{
-				Name:   []byte("share"),
-				Digest: mustDigest(expectedDirectories["/share"]),
-				Size:   expectedDirectories["/share"].Size(),
-			},
-		},
-		Files: []*castorev1pb.FileNode{},
-		Symlinks: []*castorev1pb.SymlinkNode{
-			{
-				Name:   []byte("sbin"),
-				Target: []byte("bin"),
-			},
-		},
-	}
-	// assert we populated the two fixtures properly
-	require.Equal(t, len(expectedDirectoryPaths), len(expectedDirectories))
-
-	numDirectoriesReceived := 0
-
-	actualPathInfo, err := r.Import(
-		context.Background(),
-		func(fileReader io.Reader) error {
-			// Don't really bother reading and comparing the contents here,
-			// We already verify the right digests are produced by comparing the
-			// directoryCb calls, and TestRegular ensures the reader works.
-			// This also covers the case when the client doesn't read from the reader, and that the
-			// importer will take care of reading all the way to the end no matter what.
-			return nil
-		}, func(directory *castorev1pb.Directory) error {
-			// use actualDirectoryOrder to look up the Directory object we expect at this specific invocation.
-			currentDirectoryPath := expectedDirectoryPaths[numDirectoriesReceived]
-
-			expectedDirectory, found := expectedDirectories[currentDirectoryPath]
-			require.True(t, found, "must find the current directory")
-
-			requireProtoEq(t, expectedDirectory, directory)
-
-			numDirectoriesReceived += 1
-			return nil
-		},
-	)
-	require.NoError(t, err)
-
-	expectedPathInfo := &storev1pb.PathInfo{
-		Node: &castorev1pb.Node{
-			Node: &castorev1pb.Node_Directory{
-				Directory: &castorev1pb.DirectoryNode{
-					Name:   []byte(""),
-					Digest: mustDigest(expectedDirectories["/"]),
-					Size:   expectedDirectories["/"].Size(),
-				},
-			},
-		},
-		References: [][]byte{},
-		Narinfo: &storev1pb.NARInfo{
-			NarSize: 464152,
-			NarSha256: []byte{
-				0xc6, 0xe1, 0x55, 0xb3, 0x45, 0x6e, 0x30, 0xb7, 0x61, 0x22, 0x63, 0xec, 0x09, 0x50, 0x70, 0x81, 0x1c, 0xaf, 0x8a, 0xbf, 0xd5, 0x9f, 0xaa, 0x72, 0xab, 0x82, 0xa5, 0x92, 0xef, 0xde, 0xb2, 0x53,
-			},
-			Signatures:     []*storev1pb.NARInfo_Signature{},
-			ReferenceNames: []string{},
-		},
-	}
-	requireProtoEq(t, expectedPathInfo, actualPathInfo)
-}
-
-// TestCallbackErrors ensures that errors returned from the callback function
-// bubble up to the importer process, and are not ignored.
-func TestCallbackErrors(t *testing.T) {
-	t.Run("callback file", func(t *testing.T) {
-		// Pick an example NAR with a regular file.
-		f, err := os.Open("../../testdata/onebyteregular.nar")
-		require.NoError(t, err)
-
-		r := reader.New(f)
-
-		targetErr := errors.New("expected error")
-
-		_, err = r.Import(
-			context.Background(),
-			func(fileReader io.Reader) error {
-				return targetErr
-			}, func(directory *castorev1pb.Directory) error {
-				panic("no directories expected!")
-			},
-		)
-		require.ErrorIs(t, err, targetErr)
-	})
-	t.Run("callback directory", func(t *testing.T) {
-		// Pick an example NAR with a directory node
-		f, err := os.Open("../../testdata/emptydirectory.nar")
-		require.NoError(t, err)
-
-		r := reader.New(f)
-
-		targetErr := errors.New("expected error")
-
-		_, err = r.Import(
-			context.Background(),
-			func(fileReader io.Reader) error {
-				panic("no file contents expected!")
-			}, func(directory *castorev1pb.Directory) error {
-				return targetErr
-			},
-		)
-		require.ErrorIs(t, err, targetErr)
-	})
-}
-
-// TestPopDirectories is a regression test that ensures we handle the directory
-// stack properly.
-//
-// This test case looks like:
-//
-// / (dir)
-// /test (dir)
-// /test/tested (file)
-// /tested (file)
-//
-// We used to have a bug where the second `tested` file would appear as if
-// it was in the `/test` dir because it has that dir as a string prefix.
-func TestPopDirectories(t *testing.T) {
-	f, err := os.Open("../../testdata/popdirectories.nar")
-	require.NoError(t, err)
-	defer f.Close()
-
-	r := reader.New(f)
-	_, err = r.Import(
-		context.Background(),
-		func(fileReader io.Reader) error { return nil },
-		func(directory *castorev1pb.Directory) error {
-			return directory.Validate()
-		},
-	)
-	require.NoError(t, err)
-}