-
Notifications
You must be signed in to change notification settings - Fork 106
/
statetrie.go
517 lines (450 loc) · 13.8 KB
/
statetrie.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
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
package byzcoin
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
"sync"
"go.dedis.ch/onet/v3/network"
"go.dedis.ch/protobuf"
"go.dedis.ch/cothority/v3"
"go.dedis.ch/cothority/v3/byzcoin/trie"
"go.dedis.ch/cothority/v3/darc"
"go.dedis.ch/cothority/v3/skipchain"
"go.etcd.io/bbolt"
"golang.org/x/xerrors"
)
var errKeyNotSet = xerrors.New("key not set")
// GlobalState is used to query for any data in byzcoin.
type GlobalState interface {
ReadOnlyStateTrie
ReadOnlySkipChain
TimeReader
}
// ReadOnlyStateTrie is the read-only interface for StagingStateTrie and
// StateTrie.
type ReadOnlyStateTrie interface {
// GetValues gets all the values associated with the given key.
GetValues(key []byte) (value []byte, version uint64, contractID string, darcID darc.ID, err error)
// GetProof produces an existance or absence proof for the given key.
GetProof(key []byte) (*trie.Proof, error)
// GetIndex returns the index metadata.
GetIndex() int
// GetNonce returns the nonce of the trie.
GetNonce() ([]byte, error)
// GetVersion returns the version of the ByzCoin protocol.
GetVersion() Version
// ForEach calls the callback function on every key/value pair in the
// trie, which does not include the metadata.
ForEach(func(k, v []byte) error) error
// StoreAllToReplica creates a copy of the read-only trie and applies
// the state changes to the copy. The implementation should make sure
// that the original read-only trie is not be modified.
StoreAllToReplica(StateChanges) (ReadOnlyStateTrie, error)
// GetSignerCounter returns the latest counters available.
GetSignerCounter(id darc.Identity) (uint64, error)
// LoadConfig returns the config,
// or a cache of it to speed up if there are many lookups.
LoadConfig() (*ChainConfig, error)
// LoadDarc returns a darc, or a cache of it.
LoadDarc(id darc.ID) (*darc.Darc, error)
}
// ReadOnlySkipChain holds the skipchain data.
type ReadOnlySkipChain interface {
GetLatest() (*skipchain.SkipBlock, error)
GetGenesisBlock() (*skipchain.SkipBlock, error)
GetBlock(skipchain.SkipBlockID) (*skipchain.SkipBlock, error)
GetBlockByIndex(idx int) (*skipchain.SkipBlock, error)
}
// TimeReader is an interface allowing to access time-related information
type TimeReader interface {
GetCurrentBlockTimestamp() int64
}
type globalState struct {
ReadOnlyStateTrie
ReadOnlySkipChain
TimeReader
}
var _ GlobalState = (*globalState)(nil)
// stagingStateTrie is a wrapper around trie.StagingTrie that allows for use in
// byzcoin.
type stagingStateTrie struct {
trie.StagingTrie
trieCache
sync.Mutex
}
// Clone makes a copy of the staged data of the structure, the source Trie is
// not copied.
func (t *stagingStateTrie) Clone() *stagingStateTrie {
return &stagingStateTrie{
StagingTrie: *t.StagingTrie.Clone(),
}
}
// StoreAll puts all the state changes and the index in the staging area.
func (t *stagingStateTrie) StoreAll(scs StateChanges) error {
t.Lock()
defer t.Unlock()
t.invalidate()
pairs := make([]trie.KVPair, len(scs))
for i := range pairs {
pairs[i] = &scs[i]
}
if err := t.StagingTrie.Batch(pairs); err != nil {
return xerrors.Errorf("batch failed: %v", err)
}
return nil
}
// GetValues returns the associated value, contract ID and darcID. An error is
// returned if the key does not exist or another issue occurs.
func (t *stagingStateTrie) GetValues(key []byte) (value []byte, version uint64, contractID string, darcID darc.ID, err error) {
t.Lock()
defer t.Unlock()
var buf []byte
buf, err = t.Get(key)
if err != nil {
err = xerrors.Errorf("reading trie: %v", err)
return
}
if buf == nil {
err = cothority.WrapError(errKeyNotSet)
return
}
var vals StateChangeBody
vals, err = decodeStateChangeBody(buf)
if err != nil {
err = xerrors.Errorf("decoding body: %v", err)
return
}
value = vals.Value
version = vals.Version
contractID = string(vals.ContractID)
darcID = vals.DarcID
return
}
// Commit commits the staged data to the source trie.
func (t *stagingStateTrie) Commit() error {
t.Lock()
defer t.Unlock()
return cothority.ErrorOrNil(t.StagingTrie.Commit(), "commit failed")
}
// GetIndex returns the index of the current trie.
func (t *stagingStateTrie) GetIndex() int {
t.Lock()
defer t.Unlock()
indexBuf := t.StagingTrie.GetMetadata([]byte(trieIndexKey))
if len(indexBuf) != 4 {
return -1
}
index := binary.LittleEndian.Uint32(indexBuf)
return int(index)
}
// StoreAllToReplica creates a copy of the read-only trie and applies the state
// changes to the copy.
func (t *stagingStateTrie) StoreAllToReplica(scs StateChanges) (ReadOnlyStateTrie, error) {
newTrie := t.Clone()
if err := newTrie.StoreAll(scs); err != nil {
return nil, xerrors.Errorf("replica failed to store state changes: %v", err)
}
return newTrie, nil
}
func (t *stagingStateTrie) GetSignerCounter(id darc.Identity) (uint64, error) {
return getSignerCounter(t, id.String())
}
// GetVersion returns the version of the ByzCoin protocol.
func (t *stagingStateTrie) GetVersion() Version {
t.Lock()
defer t.Unlock()
return readVersion(t)
}
func (t *stagingStateTrie) LoadConfig() (*ChainConfig, error) {
return t.loadConfigFromTrie(t)
}
func (t *stagingStateTrie) LoadDarc(id darc.ID) (*darc.Darc, error) {
return t.loadDarcFromTrie(t, id)
}
type trieCache struct {
config *ChainConfig
darcs map[string]*darc.Darc
sync.Mutex
}
// use a very defensive cache mechanism,
// where every write to the trie invalidates all the cache.
// This avoids having to search through the cache to find invalid entries on
// each write.
func (tc *trieCache) invalidate() {
tc.Lock()
tc.config = nil
tc.darcs = nil
tc.Unlock()
}
func (tc *trieCache) loadConfigFromTrie(st ReadOnlyStateTrie) (*ChainConfig, error) {
tc.Lock()
defer tc.Unlock()
if tc.config != nil {
return tc.config, nil
}
// Find the genesis-darc ID.
val, _, contract, _, err := GetValueContract(st, NewInstanceID(nil).Slice())
if err != nil {
return nil, fmt.Errorf("reading trie: %w", err)
}
if contract != ContractConfigID {
return nil, errors.New("did not get " + ContractConfigID)
}
tc.config = &ChainConfig{}
err = protobuf.DecodeWithConstructors(val, tc.config,
network.DefaultConstructors(cothority.Suite))
if err != nil {
return nil, fmt.Errorf("decoding config: %v", err)
}
return tc.config, nil
}
func (tc *trieCache) loadDarcFromTrie(st ReadOnlyStateTrie,
id darc.ID) (*darc.Darc, error) {
tc.Lock()
defer tc.Unlock()
if tc.darcs == nil {
tc.darcs = make(map[string]*darc.Darc)
} else {
if d, ok := tc.darcs[string(id)]; ok {
return d, nil
}
}
darcBuf, _, contract, _, err := st.GetValues(id)
if err != nil {
return nil, fmt.Errorf("reading trie: %v", err)
}
tc.Unlock()
config, err := tc.loadConfigFromTrie(st)
tc.Lock()
if err != nil {
return nil, fmt.Errorf("reading trie: %v", err)
}
var ok bool
for _, id := range config.DarcContractIDs {
if contract == id {
ok = true
break
}
}
if !ok {
return nil, fmt.Errorf("the contract '%s' is not in"+
" the set of DARC contracts", contract)
}
d, err := darc.NewFromProtobuf(darcBuf)
if err != nil {
return nil, fmt.Errorf("decoding darc: %v", err)
}
tc.darcs[string(id)] = d
return d, nil
}
const trieIndexKey = "trieIndexKey"
const trieVersionKey = "trieVersionKey"
// stateTrie is a wrapper around trie.Trie that support the storage of an
// index.
type stateTrie struct {
trie.Trie
trieCache
sync.Mutex
}
// loadStateTrie loads an existing StateTrie, an error is returned if no trie
// exists in db
func loadStateTrie(db *bbolt.DB, bucket []byte) (*stateTrie, error) {
t, err := trie.LoadTrie(trie.NewDiskDB(db, bucket))
if err != nil {
return nil, xerrors.Errorf("loading trie: %v", err)
}
return &stateTrie{Trie: *t}, nil
}
// newStateTrie creates a new, disk-based trie.Trie, an error is returned if
// the db already contains a trie.
func newStateTrie(db *bbolt.DB, bucket, nonce []byte) (*stateTrie, error) {
t, err := trie.NewTrie(trie.NewDiskDB(db, bucket), nonce)
if err != nil {
return nil, xerrors.Errorf("creating trie: %v", err)
}
return &stateTrie{Trie: *t}, nil
}
// StoreAll stores the state changes in the Trie.
func (t *stateTrie) StoreAll(scs StateChanges, index int, version Version) error {
return cothority.ErrorOrNil(t.VerifiedStoreAll(scs, index, version, nil), "store failed")
}
// VerifiedStoreAll stores the state changes, the index and the version as metadata. It
// checks whether the expectedRoot hash matches the computed root hash and returns an
// error if it doesn't.
func (t *stateTrie) VerifiedStoreAll(scs StateChanges, index int, version Version, expectedRoot []byte) error {
t.Lock()
defer t.Unlock()
t.invalidate()
pairs := make([]trie.KVPair, len(scs))
for i := range pairs {
pairs[i] = &scs[i]
}
return t.DB().Update(func(b trie.Bucket) error {
if err := t.BatchWithBucket(pairs, b); err != nil {
return xerrors.Errorf("batch failed: %v", err)
}
indexBuf := make([]byte, 4)
binary.LittleEndian.PutUint32(indexBuf, uint32(index))
if err := t.SetMetadataWithBucket([]byte(trieIndexKey), indexBuf, b); err != nil {
return xerrors.Errorf("storing index: %v", err)
}
versionBuf := make([]byte, 4)
binary.LittleEndian.PutUint32(versionBuf, uint32(version))
if err := t.SetMetadataWithBucket([]byte(trieVersionKey), versionBuf, b); err != nil {
return xerrors.Errorf("storing version: %v", err)
}
if expectedRoot != nil && !bytes.Equal(t.GetRootWithBucket(b), expectedRoot) {
return xerrors.New("root verification failed")
}
return nil
})
}
// GetValues returns the associated value, contractID and darcID. An error is
// returned if the key does not exist.
func (t *stateTrie) GetValues(key []byte) (value []byte, version uint64, contractID string, darcID darc.ID, err error) {
t.Lock()
defer t.Unlock()
var buf []byte
buf, err = t.Get(key)
if err != nil {
err = xerrors.Errorf("reading trie: %v", err)
return
}
if buf == nil {
err = cothority.WrapError(errKeyNotSet)
return
}
var vals StateChangeBody
vals, err = decodeStateChangeBody(buf)
if err != nil {
err = xerrors.Errorf("decoding body: %v", err)
return
}
value = vals.Value
version = vals.Version
contractID = string(vals.ContractID)
darcID = vals.DarcID
return
}
// GetIndex gets the latest index.
func (t *stateTrie) GetIndex() int {
t.Lock()
defer t.Unlock()
indexBuf := t.GetMetadata([]byte(trieIndexKey))
if indexBuf == nil {
return -1
}
return int(binary.LittleEndian.Uint32(indexBuf))
}
// GetVersion returns the version of the ByzCoin proocol.
func (t *stateTrie) GetVersion() Version {
return readVersion(t)
}
// MakeStagingStateTrie creates a StagingStateTrie from the StateTrie.
func (t *stateTrie) MakeStagingStateTrie() *stagingStateTrie {
return &stagingStateTrie{
StagingTrie: *t.MakeStagingTrie(),
}
}
// StoreAllToReplica is not supported. It cannot be implemented in an immutable
// way because writing state changes to the replica will change the underlying
// trie since the receiver is not a stagingStateTrie. Convert it to a
// stagingStateTrie and then use StoreAllToReplica.
func (t *stateTrie) StoreAllToReplica(scs StateChanges) (ReadOnlyStateTrie, error) {
return nil, xerrors.New("unsupported operation")
}
func (t *stateTrie) GetSignerCounter(id darc.Identity) (uint64, error) {
return getSignerCounter(t, id.String())
}
func (t *stateTrie) LoadConfig() (*ChainConfig, error) {
return t.loadConfigFromTrie(t)
}
func (t *stateTrie) LoadDarc(id darc.ID) (*darc.Darc, error) {
return t.loadDarcFromTrie(t, id)
}
// newMemStagingStateTrie creates an in-memory StagingStateTrie.
func newMemStagingStateTrie(nonce []byte) (*stagingStateTrie, error) {
memTrie, err := trie.NewTrie(trie.NewMemDB(), nonce)
if err != nil {
return nil, xerrors.Errorf("creating trie: %v", err)
}
et := stagingStateTrie{
StagingTrie: *memTrie.MakeStagingTrie(),
}
return &et, nil
}
// newMemStateTrie creates an in-memory StateTrie.
func newMemStateTrie(nonce []byte) (*stateTrie, error) {
memTrie, err := trie.NewTrie(trie.NewMemDB(), nonce)
if err != nil {
return nil, xerrors.Errorf("creating trie: %v", err)
}
st := stateTrie{
Trie: *memTrie,
}
return &st, nil
}
type roSkipChain struct {
inner *skipchain.Service
genesisID skipchain.SkipBlockID
currLatest skipchain.SkipBlockID
}
func newROSkipChain(s *skipchain.Service, genesisID skipchain.SkipBlockID) *roSkipChain {
return &roSkipChain{inner: s, genesisID: genesisID, currLatest: genesisID}
}
func (s *roSkipChain) GetLatest() (*skipchain.SkipBlock, error) {
sb, err := s.inner.GetDB().GetLatestByID(s.currLatest)
if err != nil {
return nil, xerrors.Errorf("read latest: %v", err)
}
s.currLatest = sb.CalculateHash()
return sb, nil
}
func (s *roSkipChain) GetGenesisBlock() (*skipchain.SkipBlock, error) {
reply, err := s.inner.GetSingleBlockByIndex(
&skipchain.GetSingleBlockByIndex{
Genesis: s.genesisID,
Index: 0,
})
if err != nil {
return nil, xerrors.Errorf("reading block: %v", err)
}
return reply.SkipBlock, nil
}
func (s *roSkipChain) GetBlock(id skipchain.SkipBlockID) (*skipchain.SkipBlock, error) {
sb := s.inner.GetDB().GetByID(id)
if sb == nil {
return nil, xerrors.New("block not found")
}
return sb, nil
}
func (s *roSkipChain) GetBlockByIndex(idx int) (*skipchain.SkipBlock, error) {
reply, err := s.inner.GetSingleBlockByIndex(
&skipchain.GetSingleBlockByIndex{
Genesis: s.genesisID,
Index: idx,
})
if err != nil {
return nil, xerrors.Errorf("reading block: %v", err)
}
return reply.SkipBlock, nil
}
type currentBlockInfo struct {
timestamp int64
}
func (info *currentBlockInfo) GetCurrentBlockTimestamp() int64 {
return info.timestamp
}
type metadataReader interface {
GetMetadata([]byte) []byte
}
func readVersion(t metadataReader) Version {
buf := t.GetMetadata([]byte(trieVersionKey))
if buf == nil {
// Early versions didn't have the protocol version stored in the
// metadata.
return 0
}
return Version(binary.LittleEndian.Uint32(buf))
}