/
traversal.go
235 lines (215 loc) · 7.22 KB
/
traversal.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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
package traversal
import (
"context"
"errors"
"fmt"
"github.com/ipfs/go-cid"
"github.com/ipfs/go-unixfsnode/data"
"github.com/ipfs/go-unixfsnode/directory"
"github.com/ipfs/go-unixfsnode/hamt"
dagpb "github.com/ipld/go-codec-dagpb"
"github.com/ipld/go-ipld-prime"
cidlink "github.com/ipld/go-ipld-prime/linking/cid"
"github.com/multiformats/go-multicodec"
)
type UnixFSVisitor interface {
OnPath(ctx context.Context, root cid.Cid, path string, cids []cid.Cid) error
OnFileRange(ctx context.Context, root cid.Cid, cid cid.Cid, depth int, byteMin uint64, byteMax uint64, leaf bool) error
OnRoot(ctx context.Context, root cid.Cid, kind int64) error
}
type recursiveVisitor struct {
UnixFSVisitor
lsys *ipld.LinkSystem
}
func (rv *recursiveVisitor) OnPath(ctx context.Context, root cid.Cid, path string, cids []cid.Cid) error {
err := rv.UnixFSVisitor.OnPath(ctx, root, path, cids)
if err != nil {
return err
}
return IterateUnixFSNode(ctx, cids[len(cids)-1], rv.lsys, rv)
}
func RecursiveVisitor(visitor UnixFSVisitor, lsys *ipld.LinkSystem) UnixFSVisitor {
return &recursiveVisitor{UnixFSVisitor: visitor, lsys: lsys}
}
type interateFunc func(context.Context, cid.Cid, dagpb.PBNode, data.UnixFSData, *ipld.LinkSystem, UnixFSVisitor) error
func noopIterate(context.Context, cid.Cid, dagpb.PBNode, data.UnixFSData, *ipld.LinkSystem, UnixFSVisitor) error {
return nil
}
var interateFuncs = map[int64]interateFunc{
data.Data_File: IterateFileLinks,
data.Data_Metadata: noopIterate,
data.Data_Raw: noopIterate,
data.Data_Symlink: noopIterate,
data.Data_Directory: IterateDirLinks,
data.Data_HAMTShard: IterateHAMTDirLinks,
}
func IterateUnixFSNode(ctx context.Context, root cid.Cid, lsys *ipld.LinkSystem, visitor UnixFSVisitor) error {
if root.Prefix().Codec == uint64(multicodec.Raw) {
return visitor.OnRoot(ctx, root, data.Data_Raw)
}
nd, err := lsys.Load(ipld.LinkContext{Ctx: ctx}, cidlink.Link{Cid: root}, dagpb.Type.PBNode)
if err != nil {
return err
}
pbnd, ok := nd.(dagpb.PBNode)
if !ok {
return hamt.ErrNotProtobuf
}
if !pbnd.FieldData().Exists() {
return hamt.ErrNotUnixFSNode
}
ufsdata, err := data.DecodeUnixFSData(pbnd.FieldData().Must().Bytes())
if err != nil {
return err
}
dt := ufsdata.DataType.Int()
if err := visitor.OnRoot(ctx, root, dt); err != nil {
return err
}
return interateFuncs[dt](ctx, root, pbnd, ufsdata, lsys, visitor)
}
// NewUnixFSHAMTShard attempts to construct a UnixFSHAMTShard node from the base protobuf node plus
// a decoded UnixFSData structure
func IterateHAMTDirLinks(ctx context.Context, root cid.Cid, substrate dagpb.PBNode, data data.UnixFSData, lsys *ipld.LinkSystem, visitor UnixFSVisitor) error {
return iterateHAMTDirLinks(ctx, root, substrate, data, lsys, nil, visitor)
}
func iterateHAMTDirLinks(ctx context.Context, root cid.Cid, substrate dagpb.PBNode, ufsdata data.UnixFSData, lsys *ipld.LinkSystem, cidsSoFar []cid.Cid, visitor UnixFSVisitor) error {
_, err := hamt.NewUnixFSHAMTShard(ctx, substrate, ufsdata, lsys)
if err != nil {
return err
}
maxPadLen := maxPadLength(ufsdata)
itr := substrate.FieldLinks().Iterator()
st := stringTransformer{maxPadLen: maxPadLen}
for !itr.Done() {
_, next := itr.Next()
isValue, err := isValueLink(next, maxPadLen)
if err != nil {
return err
}
if isValue {
if next.FieldName().Exists() {
name := st.transformNameNode(next.FieldName().Must())
onPathCids := make([]cid.Cid, 0, len(cidsSoFar)+1)
// copy array before handing off, so further modifications do not affect result
onPathCids = append(onPathCids, cidsSoFar...)
onPathCids = append(onPathCids, next.FieldHash().Link().(cidlink.Link).Cid)
if err := visitor.OnPath(ctx, root, name.String(), onPathCids); err != nil {
return err
}
}
continue
}
nd, err := lsys.Load(ipld.LinkContext{Ctx: ctx}, next.FieldHash().Link(), dagpb.Type.PBNode)
if err != nil {
return err
}
pbnd, ok := nd.(dagpb.PBNode)
if !ok {
return hamt.ErrNotProtobuf
}
if !pbnd.FieldData().Exists() {
return hamt.ErrNotUnixFSNode
}
nextData, err := data.DecodeUnixFSData(pbnd.FieldData().Must().Bytes())
if err != nil {
return err
}
if err := iterateHAMTDirLinks(ctx, root, pbnd, nextData, lsys, append(cidsSoFar, next.FieldHash().Link().(cidlink.Link).Cid), visitor); err != nil {
return err
}
}
return nil
}
type stringTransformer struct {
maxPadLen int
}
func (s stringTransformer) transformNameNode(nd dagpb.String) dagpb.String {
nb := dagpb.Type.String.NewBuilder()
err := nb.AssignString(nd.String()[s.maxPadLen:])
if err != nil {
return nil
}
return nb.Build().(dagpb.String)
}
func maxPadLength(nd data.UnixFSData) int {
return len(fmt.Sprintf("%X", nd.FieldFanout().Must().Int()-1))
}
func isValueLink(pbLink dagpb.PBLink, maxPadLen int) (bool, error) {
if !pbLink.FieldName().Exists() {
return false, hamt.ErrMissingLinkName
}
name := pbLink.FieldName().Must().String()
if len(name) < maxPadLen {
return false, hamt.ErrInvalidLinkName{Name: name}
}
if len(name) == maxPadLen {
return false, nil
}
return true, nil
}
func IterateDirLinks(ctx context.Context, root cid.Cid, substrate dagpb.PBNode, data data.UnixFSData, lsys *ipld.LinkSystem, visitor UnixFSVisitor) error {
dir, err := directory.NewUnixFSBasicDir(ctx, substrate, data, lsys)
if err != nil {
return err
}
iter := dir.(directory.UnixFSBasicDir).Iterator()
for !iter.Done() {
path, link := iter.Next()
if err := visitor.OnPath(ctx, root, path.String(), []cid.Cid{link.Link().(cidlink.Link).Cid}); err != nil {
return err
}
}
return nil
}
func IterateFileLinks(ctx context.Context, root cid.Cid, substrate dagpb.PBNode, data data.UnixFSData, lsys *ipld.LinkSystem, visitor UnixFSVisitor) error {
return iterateFileLinks(ctx, root, substrate, data, lsys, 0, 0, visitor)
}
func iterateFileLinks(ctx context.Context, root cid.Cid, substrate dagpb.PBNode, ufsdata data.UnixFSData, lsys *ipld.LinkSystem, bytesOffset uint64, depth int, visitor UnixFSVisitor) error {
iter := substrate.Links.Iterator()
for !iter.Done() {
idx, next := iter.Next()
nextCid := next.Hash.Link().(cidlink.Link).Cid
var nextSize uint64
var leaf bool
if nextCid.Prefix().Codec == cid.Raw {
if !next.Tsize.Exists() {
return errors.New("missing t-size")
}
nextSize = uint64(next.Tsize.Must().Int())
leaf = true
} else {
nextSize = uint64(ufsdata.BlockSizes.Lookup(idx).Int())
nd, err := lsys.Load(ipld.LinkContext{Ctx: ctx}, next.Hash.Link(), dagpb.Type.PBNode)
if err != nil {
return err
}
pbnd, ok := nd.(dagpb.PBNode)
if !ok {
return hamt.ErrNotProtobuf
}
if !pbnd.FieldData().Exists() {
return hamt.ErrNotUnixFSNode
}
nextData, err := data.DecodeUnixFSData(pbnd.FieldData().Must().Bytes())
if err != nil {
return err
}
switch nextData.DataType.Int() {
case data.Data_Raw:
leaf = true
case data.Data_File:
if err := iterateFileLinks(ctx, root, pbnd, nextData, lsys, bytesOffset, depth+1, visitor); err != nil {
return err
}
default:
return data.ErrInvalidDataType{DataType: nextData.DataType.Int()}
}
}
if err := visitor.OnFileRange(ctx, root, nextCid, depth, bytesOffset, bytesOffset+nextSize, leaf); err != nil {
return err
}
bytesOffset += nextSize
}
return nil
}