forked from ipfs/go-unixfs
/
unixfile.go
318 lines (272 loc) · 6.53 KB
/
unixfile.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
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
package unixfile
import (
"context"
"encoding/json"
"errors"
"fmt"
ft "github.com/TRON-US/go-unixfs"
uio "github.com/TRON-US/go-unixfs/io"
"github.com/TRON-US/go-unixfs/util"
chunker "github.com/TRON-US/go-btfs-chunker"
files "github.com/TRON-US/go-btfs-files"
cid "github.com/ipfs/go-cid"
ipld "github.com/ipfs/go-ipld-format"
dag "github.com/ipfs/go-merkledag"
)
// Number to file to prefetch in directories
// TODO: should we allow setting this via context hint?
const prefetchFiles = 4
var (
ErrNilTreeBuf = errors.New("treeBuf is nil for directory node")
)
type ufsDirectory struct {
ctx context.Context
dserv ipld.DAGService
dir uio.Directory
size int64
}
type ufsIterator struct {
ctx context.Context
files chan *ipld.Link
dserv ipld.DAGService
curName string
curFile files.Node
err error
errCh chan error
}
func (it *ufsIterator) Name() string {
return it.curName
}
func (it *ufsIterator) Node() files.Node {
return it.curFile
}
func (it *ufsIterator) Next() bool {
if it.err != nil {
return false
}
var l *ipld.Link
var ok bool
for !ok {
if it.files == nil && it.errCh == nil {
return false
}
select {
case l, ok = <-it.files:
if !ok {
it.files = nil
}
case err := <-it.errCh:
it.errCh = nil
it.err = err
if err != nil {
return false
}
}
}
it.curFile = nil
nd, err := l.GetNode(it.ctx, it.dserv)
if err != nil {
it.err = err
return false
}
it.curName = l.Name
if it.curName == uio.SmallestString {
return it.err == nil
}
it.curFile, it.err = NewUnixfsFile(it.ctx, it.dserv, nd, UnixfsFileOptions{})
return it.err == nil
}
func (it *ufsIterator) Err() error {
return it.err
}
func (it *ufsIterator) BreadthFirstTraversal() {
}
func (d *ufsDirectory) Close() error {
return nil
}
func (d *ufsDirectory) Entries() files.DirIterator {
fileCh := make(chan *ipld.Link, prefetchFiles)
errCh := make(chan error, 1)
// Invoke goroutine to provide links of the current receiver `d` via `fileCh`.
go func() {
errCh <- d.dir.ForEachLink(d.ctx, func(link *ipld.Link) error {
if d.ctx.Err() != nil {
return d.ctx.Err()
}
select {
case fileCh <- link:
case <-d.ctx.Done():
return d.ctx.Err()
}
return nil
})
close(errCh)
close(fileCh)
}()
return &ufsIterator{
ctx: d.ctx,
files: fileCh,
errCh: errCh,
dserv: d.dserv,
}
}
func (d *ufsDirectory) Size() (int64, error) {
return d.size, nil
}
func (f *ufsDirectory) SetSize(size int64) error {
return errors.New("not supported")
}
func (f *ufsDirectory) IsReedSolomon() bool {
return false
}
type ufsFile struct {
uio.DagReader
}
func (f *ufsFile) Size() (int64, error) {
return int64(f.DagReader.Size()), nil
}
func newUnixfsDir(ctx context.Context, dserv ipld.DAGService, nd *dag.ProtoNode) (files.Directory, error) {
dir, err := uio.NewDirectoryFromNode(dserv, nd)
if err != nil {
return nil, err
}
size, err := nd.Size()
if err != nil {
return nil, err
}
return &ufsDirectory{
ctx: ctx,
dserv: dserv,
dir: dir,
size: int64(size),
}, nil
}
type UnixfsFileOptions struct {
Meta bool
RepairShards []cid.Cid
}
// NewUnixFsFile returns a DagReader for the 'nd' root node.
// If opts.Meta = true, only return a valid metadata node if it exists. If not, return error.
// If opts.Meta = false, return only the data contents.
// If opts.Meta = false && opts.RepairShards != nil,
// the shards would be reconstructed and added on this node.
func NewUnixfsFile(ctx context.Context, dserv ipld.DAGService, nd ipld.Node,
opts UnixfsFileOptions) (files.Node, error) {
rawNode := false
switch dn := nd.(type) {
case *dag.ProtoNode:
fsn, err := ft.FSNodeFromBytes(dn.Data())
if err != nil {
return nil, err
}
if fsn.IsDir() {
if !opts.Meta {
return newUnixfsDir(ctx, dserv, dn)
}
// Now the current case is when the dir node may contain metadata.
} else if fsn.Type() == ft.TSymlink {
return files.NewLinkFile(string(fsn.Data()), nil), nil
}
case *dag.RawNode:
rawNode = true
default:
return nil, errors.New("unknown node type")
}
var dr uio.DagReader
// Keep 'nd' if raw node
if !rawNode {
// Split metadata node and data node if available
dataNode, metaNode, err := util.CheckAndSplitMetadata(ctx, nd, dserv, opts.Meta)
if err != nil {
return nil, err
}
// Return just metadata if available
if opts.Meta {
if metaNode == nil {
return nil, errors.New("no metadata is available")
}
nd = metaNode
} else {
// Select DagReader based on metadata information
if metaNode != nil {
metaStruct, err := ObtainMetadataFromDag(ctx, metaNode, dserv)
if err != nil {
if err == ErrNilTreeBuf {
return nil, fmt.Errorf("treeBuf is nil for [%s]", nd.Cid().String())
}
return nil, err
}
rsMeta := metaStruct.RsMeta
if rsMeta.NumData > 0 && rsMeta.NumParity > 0 && rsMeta.FileSize > 0 {
// TODO: if isDir uio.New..DagForDirectory, else New..File that wraps reader builder
if rsMeta.IsDir {
return NewReedSolomonDirectory(ctx, nd, dataNode, dserv, opts, metaStruct)
} else {
return NewReedSolomonStandaloneFile(ctx, nd, dataNode, dserv, opts, metaStruct)
}
}
}
nd = dataNode
}
}
// Use default dag reader if not a special type reader
if dr == nil {
var err error
dr, err = uio.NewDagReader(ctx, nd, dserv)
if err != nil {
return nil, err
}
}
return &ufsFile{
DagReader: dr,
}, nil
}
type MetadataStruct struct {
Buff []byte
RsMeta *chunker.RsMetaMap
DirRoot *uio.DirNode
}
// ObtainMetadataFromDag returns MetadataStruct object.
func ObtainMetadataFromDag(ctx context.Context, metaNode ipld.Node, dserv ipld.NodeGetter) (*MetadataStruct, error) {
mdr, err := uio.NewDagReader(ctx, metaNode, dserv)
if err != nil {
return nil, err
}
// Read all metadata
buf := make([]byte, mdr.Size())
_, err = mdr.CtxReadFull(ctx, buf)
if err != nil {
return nil, err
}
// Split the buf into two byte arrays.
metaBuf, treeBuf, err := util.GetMetadataList(buf)
if err != nil {
return nil, err
}
// Read RsMetaMap
var rsMeta chunker.RsMetaMap
err = json.Unmarshal(metaBuf, &rsMeta)
if err != nil {
return nil, err
}
// Read tree metadata if the Dag is for directory.
var root *uio.DirNode
if rsMeta.IsDir {
if treeBuf == nil {
return nil, ErrNilTreeBuf
}
tmp := uio.DirNode{}
err = json.Unmarshal(treeBuf, &tmp)
if err != nil {
return nil, err
}
root = &tmp
}
return &MetadataStruct{
Buff: buf,
RsMeta: &rsMeta,
DirRoot: root,
}, nil
}
var _ files.Directory = &ufsDirectory{}
var _ files.File = &ufsFile{}