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
|
// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package state
import (
"bytes"
"fmt"
"io"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
)
var emptyCodeHash = crypto.Keccak256(nil)
type Code []byte
func (self Code) String() string {
return string(self) //strings.Join(Disassemble(self), " ")
}
type Storage map[common.Hash]common.Hash
func (self Storage) String() (str string) {
for key, value := range self {
str += fmt.Sprintf("%X : %X\n", key, value)
}
return
}
func (self Storage) Copy() Storage {
cpy := make(Storage)
for key, value := range self {
cpy[key] = value
}
return cpy
}
// stateObject represents an Ethereum account which is being modified.
//
// The usage pattern is as follows:
// First you need to obtain a state object.
// Account values can be accessed and modified through the object.
// Finally, call CommitTrie to write the modified storage trie into a database.
type stateObject struct {
address common.Address // Ethereum address of this account
data Account
db *StateDB
// DB error.
// State objects are used by the consensus core and VM which are
// unable to deal with database-level errors. Any error that occurs
// during a database read is memoized here and will eventually be returned
// by StateDB.Commit.
dbErr error
// Write caches.
trie *trie.SecureTrie // storage trie, which becomes non-nil on first access
code Code // contract bytecode, which gets set when code is loaded
cachedStorage Storage // Storage entry cache to avoid duplicate reads
dirtyStorage Storage // Storage entries that need to be flushed to disk
// Cache flags.
// When an object is marked suicided it will be delete from the trie
// during the "update" phase of the state transition.
dirtyCode bool // true if the code was updated
suicided bool
touched bool
deleted bool
onDirty func(addr common.Address) // Callback method to mark a state object newly dirty
}
// empty returns whether the account is considered empty.
func (s *stateObject) empty() bool {
return s.data.Nonce == 0 && s.data.Balance.Sign() == 0 && bytes.Equal(s.data.CodeHash, emptyCodeHash)
}
// Account is the Ethereum consensus representation of accounts.
// These objects are stored in the main account trie.
type Account struct {
Nonce uint64
Balance *big.Int
Root common.Hash // merkle root of the storage trie
CodeHash []byte
}
// newObject creates a state object.
func newObject(db *StateDB, address common.Address, data Account, onDirty func(addr common.Address)) *stateObject {
if data.Balance == nil {
data.Balance = new(big.Int)
}
if data.CodeHash == nil {
data.CodeHash = emptyCodeHash
}
return &stateObject{db: db, address: address, data: data, cachedStorage: make(Storage), dirtyStorage: make(Storage), onDirty: onDirty}
}
// EncodeRLP implements rlp.Encoder.
func (c *stateObject) EncodeRLP(w io.Writer) error {
return rlp.Encode(w, c.data)
}
// setError remembers the first non-nil error it is called with.
func (self *stateObject) setError(err error) {
if self.dbErr == nil {
self.dbErr = err
}
}
func (self *stateObject) markSuicided() {
self.suicided = true
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
func (c *stateObject) touch() {
c.db.journal = append(c.db.journal, touchChange{
account: &c.address,
prev: c.touched,
})
if c.onDirty != nil {
c.onDirty(c.Address())
c.onDirty = nil
}
c.touched = true
}
func (c *stateObject) getTrie(db trie.Database) *trie.SecureTrie {
if c.trie == nil {
var err error
c.trie, err = trie.NewSecure(c.data.Root, db, 0)
if err != nil {
c.trie, _ = trie.NewSecure(common.Hash{}, db, 0)
c.setError(fmt.Errorf("can't create storage trie: %v", err))
}
}
return c.trie
}
// GetState returns a value in account storage.
func (self *stateObject) GetState(db trie.Database, key common.Hash) common.Hash {
value, exists := self.cachedStorage[key]
if exists {
return value
}
// Load from DB in case it is missing.
if enc := self.getTrie(db).Get(key[:]); len(enc) > 0 {
_, content, _, err := rlp.Split(enc)
if err != nil {
self.setError(err)
}
value.SetBytes(content)
}
if (value != common.Hash{}) {
self.cachedStorage[key] = value
}
return value
}
// SetState updates a value in account storage.
func (self *stateObject) SetState(db trie.Database, key, value common.Hash) {
self.db.journal = append(self.db.journal, storageChange{
account: &self.address,
key: key,
prevalue: self.GetState(db, key),
})
self.setState(key, value)
}
func (self *stateObject) setState(key, value common.Hash) {
self.cachedStorage[key] = value
self.dirtyStorage[key] = value
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
// updateTrie writes cached storage modifications into the object's storage trie.
func (self *stateObject) updateTrie(db trie.Database) {
tr := self.getTrie(db)
for key, value := range self.dirtyStorage {
delete(self.dirtyStorage, key)
if (value == common.Hash{}) {
tr.Delete(key[:])
continue
}
// Encoding []byte cannot fail, ok to ignore the error.
v, _ := rlp.EncodeToBytes(bytes.TrimLeft(value[:], "\x00"))
tr.Update(key[:], v)
}
}
// UpdateRoot sets the trie root to the current root hash of
func (self *stateObject) updateRoot(db trie.Database) {
self.updateTrie(db)
self.data.Root = self.trie.Hash()
}
// CommitTrie the storage trie of the object to dwb.
// This updates the trie root.
func (self *stateObject) CommitTrie(db trie.Database, dbw trie.DatabaseWriter) error {
self.updateTrie(db)
if self.dbErr != nil {
return self.dbErr
}
root, err := self.trie.CommitTo(dbw)
if err == nil {
self.data.Root = root
}
return err
}
// AddBalance removes amount from c's balance.
// It is used to add funds to the destination account of a transfer.
func (c *stateObject) AddBalance(amount *big.Int) {
// EIP158: We must check emptiness for the objects such that the account
// clearing (0,0,0 objects) can take effect.
if amount.Sign() == 0 {
if c.empty() {
c.touch()
}
return
}
c.SetBalance(new(big.Int).Add(c.Balance(), amount))
}
// SubBalance removes amount from c's balance.
// It is used to remove funds from the origin account of a transfer.
func (c *stateObject) SubBalance(amount *big.Int) {
if amount.Sign() == 0 {
return
}
c.SetBalance(new(big.Int).Sub(c.Balance(), amount))
}
func (self *stateObject) SetBalance(amount *big.Int) {
self.db.journal = append(self.db.journal, balanceChange{
account: &self.address,
prev: new(big.Int).Set(self.data.Balance),
})
self.setBalance(amount)
}
func (self *stateObject) setBalance(amount *big.Int) {
self.data.Balance = amount
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
// Return the gas back to the origin. Used by the Virtual machine or Closures
func (c *stateObject) ReturnGas(gas *big.Int) {}
func (self *stateObject) deepCopy(db *StateDB, onDirty func(addr common.Address)) *stateObject {
stateObject := newObject(db, self.address, self.data, onDirty)
stateObject.trie = self.trie
stateObject.code = self.code
stateObject.dirtyStorage = self.dirtyStorage.Copy()
stateObject.cachedStorage = self.dirtyStorage.Copy()
stateObject.suicided = self.suicided
stateObject.dirtyCode = self.dirtyCode
stateObject.deleted = self.deleted
return stateObject
}
//
// Attribute accessors
//
// Returns the address of the contract/account
func (c *stateObject) Address() common.Address {
return c.address
}
// Code returns the contract code associated with this object, if any.
func (self *stateObject) Code(db trie.Database) []byte {
if self.code != nil {
return self.code
}
if bytes.Equal(self.CodeHash(), emptyCodeHash) {
return nil
}
code, err := db.Get(self.CodeHash())
if err != nil {
self.setError(fmt.Errorf("can't load code hash %x: %v", self.CodeHash(), err))
}
self.code = code
return code
}
func (self *stateObject) SetCode(codeHash common.Hash, code []byte) {
prevcode := self.Code(self.db.db)
self.db.journal = append(self.db.journal, codeChange{
account: &self.address,
prevhash: self.CodeHash(),
prevcode: prevcode,
})
self.setCode(codeHash, code)
}
func (self *stateObject) setCode(codeHash common.Hash, code []byte) {
self.code = code
self.data.CodeHash = codeHash[:]
self.dirtyCode = true
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
func (self *stateObject) SetNonce(nonce uint64) {
self.db.journal = append(self.db.journal, nonceChange{
account: &self.address,
prev: self.data.Nonce,
})
self.setNonce(nonce)
}
func (self *stateObject) setNonce(nonce uint64) {
self.data.Nonce = nonce
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
func (self *stateObject) CodeHash() []byte {
return self.data.CodeHash
}
func (self *stateObject) Balance() *big.Int {
return self.data.Balance
}
func (self *stateObject) Nonce() uint64 {
return self.data.Nonce
}
// Never called, but must be present to allow stateObject to be used
// as a vm.Account interface that also satisfies the vm.ContractRef
// interface. Interfaces are awesome.
func (self *stateObject) Value() *big.Int {
panic("Value on stateObject should never be called")
}
|