aboutsummaryrefslogtreecommitdiffstats
path: root/light/state_object.go
blob: 08c209d7d82bb833ad4dad562bfa1dc0f9f3ad83 (plain) (blame)
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
// Copyright 2015 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 light

import (
    "bytes"
    "fmt"
    "math/big"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/rlp"
    "golang.org/x/net/context"
)

var emptyCodeHash = crypto.Keccak256(nil)

// Code represents a contract code in binary form
type Code []byte

// String returns a string representation of the code
func (self Code) String() string {
    return string(self) //strings.Join(Disassemble(self), " ")
}

// Storage is a memory map cache of a contract storage
type Storage map[string]common.Hash

// String returns a string representation of the storage cache
func (self Storage) String() (str string) {
    for key, value := range self {
        str += fmt.Sprintf("%X : %X\n", key, value)
    }

    return
}

// Copy copies the contents of a storage cache
func (self Storage) Copy() Storage {
    cpy := make(Storage)
    for key, value := range self {
        cpy[key] = value
    }

    return cpy
}

// StateObject is a memory representation of an account or contract and its storage.
// This version is ODR capable, caching only the already accessed part of the
// storage, retrieving unknown parts on-demand from the ODR backend. Changes are
// never stored in the local database, only in the memory objects.
type StateObject struct {
    odr  OdrBackend
    trie *LightTrie

    // Address belonging to this account
    address common.Address
    // The balance of the account
    balance *big.Int
    // The nonce of the account
    nonce uint64
    // The code hash if code is present (i.e. a contract)
    codeHash []byte
    // The code for this account
    code Code
    // Cached storage (flushed when updated)
    storage Storage

    // Mark for deletion
    // When an object is marked for deletion it will be delete from the trie
    // during the "update" phase of the state transition
    remove  bool
    deleted bool
    dirty   bool
}

// NewStateObject creates a new StateObject of the specified account address
func NewStateObject(address common.Address, odr OdrBackend) *StateObject {
    object := &StateObject{
        odr:      odr,
        address:  address,
        balance:  new(big.Int),
        dirty:    true,
        codeHash: emptyCodeHash,
        storage:  make(Storage),
    }
    object.trie = NewLightTrie(common.Hash{}, odr, true)
    return object
}

// MarkForDeletion marks an account to be removed
func (self *StateObject) MarkForDeletion() {
    self.remove = true
    self.dirty = true

    if glog.V(logger.Core) {
        glog.Infof("%x: #%d %v X\n", self.Address(), self.nonce, self.balance)
    }
}

// getAddr gets the storage value at the given address from the trie
func (c *StateObject) getAddr(ctx context.Context, addr common.Hash) (common.Hash, error) {
    var ret []byte
    val, err := c.trie.Get(ctx, addr[:])
    if err != nil {
        return common.Hash{}, err
    }
    rlp.DecodeBytes(val, &ret)
    return common.BytesToHash(ret), nil
}

// Storage returns the storage cache object of the account
func (self *StateObject) Storage() Storage {
    return self.storage
}

// GetState returns the storage value at the given address from either the cache
// or the trie
func (self *StateObject) GetState(ctx context.Context, key common.Hash) (common.Hash, error) {
    strkey := key.Str()
    value, exists := self.storage[strkey]
    if !exists {
        var err error
        value, err = self.getAddr(ctx, key)
        if err != nil {
            return common.Hash{}, err
        }
        if (value != common.Hash{}) {
            self.storage[strkey] = value
        }
    }

    return value, nil
}

// SetState sets the storage value at the given address
func (self *StateObject) SetState(k, value common.Hash) {
    self.storage[k.Str()] = value
    self.dirty = true
}

// AddBalance adds the given amount to the account balance
func (c *StateObject) AddBalance(amount *big.Int) {
    c.SetBalance(new(big.Int).Add(c.balance, amount))

    if glog.V(logger.Core) {
        glog.Infof("%x: #%d %v (+ %v)\n", c.Address(), c.nonce, c.balance, amount)
    }
}

// SubBalance subtracts the given amount from the account balance
func (c *StateObject) SubBalance(amount *big.Int) {
    c.SetBalance(new(big.Int).Sub(c.balance, amount))

    if glog.V(logger.Core) {
        glog.Infof("%x: #%d %v (- %v)\n", c.Address(), c.nonce, c.balance, amount)
    }
}

// SetBalance sets the account balance to the given amount
func (c *StateObject) SetBalance(amount *big.Int) {
    c.balance = amount
    c.dirty = true
}

// Copy creates a copy of the state object
func (self *StateObject) Copy() *StateObject {
    stateObject := NewStateObject(self.Address(), self.odr)
    stateObject.balance.Set(self.balance)
    stateObject.codeHash = common.CopyBytes(self.codeHash)
    stateObject.nonce = self.nonce
    stateObject.trie = self.trie
    stateObject.code = common.CopyBytes(self.code)
    stateObject.storage = self.storage.Copy()
    stateObject.remove = self.remove
    stateObject.dirty = self.dirty
    stateObject.deleted = self.deleted

    return stateObject
}

//
// Attribute accessors
//

// Balance returns the account balance
func (self *StateObject) Balance() *big.Int {
    return self.balance
}

// Address returns the address of the contract/account
func (c *StateObject) Address() common.Address {
    return c.address
}

// Code returns the contract code
func (self *StateObject) Code() []byte {
    return self.code
}

// SetCode sets the contract code
func (self *StateObject) SetCode(code []byte) {
    self.code = code
    self.codeHash = crypto.Keccak256(code)
    self.dirty = true
}

// SetNonce sets the account nonce
func (self *StateObject) SetNonce(nonce uint64) {
    self.nonce = nonce
    self.dirty = true
}

// Nonce returns the account nonce
func (self *StateObject) Nonce() uint64 {
    return self.nonce
}

// Encoding

type extStateObject struct {
    Nonce    uint64
    Balance  *big.Int
    Root     common.Hash
    CodeHash []byte
}

// DecodeObject decodes an RLP-encoded state object.
func DecodeObject(ctx context.Context, address common.Address, odr OdrBackend, data []byte) (*StateObject, error) {
    var (
        obj = &StateObject{address: address, odr: odr, storage: make(Storage)}
        ext extStateObject
        err error
    )
    if err = rlp.DecodeBytes(data, &ext); err != nil {
        return nil, err
    }
    obj.trie = NewLightTrie(ext.Root, odr, true)
    if !bytes.Equal(ext.CodeHash, emptyCodeHash) {
        if obj.code, err = retrieveNodeData(ctx, obj.odr, common.BytesToHash(ext.CodeHash)); err != nil {
            return nil, fmt.Errorf("can't find code for hash %x: %v", ext.CodeHash, err)
        }
    }
    obj.nonce = ext.Nonce
    obj.balance = ext.Balance
    obj.codeHash = ext.CodeHash
    return obj, nil
}