-
Notifications
You must be signed in to change notification settings - Fork 9
/
digest_parsing_directory.go
98 lines (87 loc) · 3.5 KB
/
digest_parsing_directory.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
package virtual
import (
"context"
"strconv"
"strings"
"github.com/buildbarn/bb-remote-execution/pkg/filesystem/virtual"
"github.com/buildbarn/bb-storage/pkg/digest"
"github.com/buildbarn/bb-storage/pkg/filesystem"
"github.com/buildbarn/bb-storage/pkg/filesystem/path"
)
// DigestLookupFunc is called by directories created using
// NewDigestParsingDirectory to complete the parsing of a digest. The
// callback can yield a directory or file corresponding with the digest.
type DigestLookupFunc func(digest digest.Digest) (virtual.DirectoryChild, virtual.Status)
type digestParsingDirectory struct {
nonIterableDirectory
virtual.ReadOnlyDirectory
digestFunction digest.Function
lookupFunc DigestLookupFunc
}
// NewDigestParsingDirectory creates a directory that can be exposed
// through FUSE that parses filenames as REv2 digests.
//
// Though REv2 uses ByteStream paths that encode digests in the form of
// {hash}/{sizeBytes}, this type uses the format {hash}-{sizeBytes}.
// This is done to ensure every resulting file only uses a single inode,
// as opposed to two.
func NewDigestParsingDirectory(digestFunction digest.Function, lookupFunc DigestLookupFunc) virtual.Directory {
return &digestParsingDirectory{
digestFunction: digestFunction,
lookupFunc: lookupFunc,
}
}
func (d *digestParsingDirectory) VirtualGetAttributes(ctx context.Context, requested virtual.AttributesMask, attributes *virtual.Attributes) {
attributes.SetChangeID(0)
attributes.SetFileType(filesystem.FileTypeDirectory)
attributes.SetLinkCount(virtual.ImplicitDirectoryLinkCount)
attributes.SetPermissions(virtual.PermissionsExecute)
attributes.SetSizeBytes(0)
}
func (d *digestParsingDirectory) parseFilename(name path.Component) (digest.Digest, bool) {
n := name.String()
i := strings.LastIndex(n, "-")
if i < 0 {
return digest.BadDigest, false
}
sizeBytes, err := strconv.ParseInt(n[i+1:], 10, 64)
if err != nil {
return digest.BadDigest, false
}
fileDigest, err := d.digestFunction.NewDigest(n[:i], sizeBytes)
if err != nil {
return digest.BadDigest, false
}
return fileDigest, true
}
func (d *digestParsingDirectory) VirtualLookup(ctx context.Context, name path.Component, requested virtual.AttributesMask, out *virtual.Attributes) (virtual.DirectoryChild, virtual.Status) {
digest, ok := d.parseFilename(name)
if !ok {
return virtual.DirectoryChild{}, virtual.StatusErrNoEnt
}
child, s := d.lookupFunc(digest)
if s != virtual.StatusOK {
return virtual.DirectoryChild{}, s
}
child.GetNode().VirtualGetAttributes(ctx, requested, out)
return child, s
}
func (d *digestParsingDirectory) VirtualOpenChild(ctx context.Context, name path.Component, shareAccess virtual.ShareMask, createAttributes *virtual.Attributes, existingOptions *virtual.OpenExistingOptions, requested virtual.AttributesMask, openedFileAttributes *virtual.Attributes) (virtual.Leaf, virtual.AttributesMask, virtual.ChangeInfo, virtual.Status) {
digest, ok := d.parseFilename(name)
if !ok {
return virtual.ReadOnlyDirectoryOpenChildDoesntExist(createAttributes)
}
if existingOptions == nil {
return nil, 0, virtual.ChangeInfo{}, virtual.StatusErrExist
}
child, s := d.lookupFunc(digest)
if s != virtual.StatusOK {
return nil, 0, virtual.ChangeInfo{}, s
}
directory, leaf := child.GetPair()
if directory != nil {
return nil, 0, virtual.ChangeInfo{}, virtual.StatusErrIsDir
}
s = leaf.VirtualOpenSelf(ctx, shareAccess, existingOptions, requested, openedFileAttributes)
return leaf, existingOptions.ToAttributesMask(), virtual.ChangeInfo{}, s
}