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
|
package ethchain
import (
"github.com/ethereum/eth-go/ethutil"
"math/big"
)
// States within the ethereum protocol are used to store anything
// within the merkle trie. States take care of caching and storing
// nested states. It's the general query interface to retrieve:
// * Contracts
// * Accounts
type State struct {
// The trie for this structure
trie *ethutil.Trie
// Nested states
states map[string]*State
}
// Create a new state from a given trie
func NewState(trie *ethutil.Trie) *State {
return &State{trie: trie, states: make(map[string]*State)}
}
// Resets the trie and all siblings
func (s *State) Reset() {
s.trie.Undo()
// Reset all nested states
for _, state := range s.states {
state.Reset()
}
}
// Syncs the trie and all siblings
func (s *State) Sync() {
// Sync all nested states
for _, state := range s.states {
state.Sync()
}
s.trie.Sync()
}
// Purges the current trie.
func (s *State) Purge() int {
return s.trie.NewIterator().Purge()
}
func (s *State) GetContract(addr []byte) *StateObject {
data := s.trie.Get(string(addr))
if data == "" {
return nil
}
// build contract
contract := NewStateObjectFromBytes(addr, []byte(data))
// Check if there's a cached state for this contract
cachedState := s.states[string(addr)]
if cachedState != nil {
contract.state = cachedState
} else {
// If it isn't cached, cache the state
s.states[string(addr)] = contract.state
}
return contract
}
func (s *State) GetAccount(addr []byte) (account *StateObject) {
data := s.trie.Get(string(addr))
if data == "" {
account = NewAccount(addr, big.NewInt(0))
} else {
account = NewStateObjectFromBytes(addr, []byte(data))
}
return
}
func (s *State) Cmp(other *State) bool {
return s.trie.Cmp(other.trie)
}
func (s *State) Copy() *State {
return NewState(s.trie.Copy())
}
type ObjType byte
const (
NilTy ObjType = iota
AccountTy
ContractTy
UnknownTy
)
// Returns the object stored at key and the type stored at key
// Returns nil if nothing is stored
func (s *State) GetStateObject(key []byte) (*ethutil.Value, ObjType) {
// Fetch data from the trie
data := s.trie.Get(string(key))
// Returns the nil type, indicating nothing could be retrieved.
// Anything using this function should check for this ret val
if data == "" {
return nil, NilTy
}
var typ ObjType
val := ethutil.NewValueFromBytes([]byte(data))
// Check the length of the retrieved value.
// Len 2 = Account
// Len 3 = Contract
// Other = invalid for now. If other types emerge, add them here
if val.Len() == 2 {
typ = AccountTy
} else if val.Len() == 3 {
typ = ContractTy
} else {
typ = UnknownTy
}
return val, typ
}
// Updates any given state object
func (s *State) UpdateStateObject(object *StateObject) {
addr := object.Address()
if object.state != nil {
s.states[string(addr)] = object.state
}
s.trie.Update(string(addr), string(object.RlpEncode()))
}
func (s *State) Put(key, object []byte) {
s.trie.Update(string(key), string(object))
}
func (s *State) Root() interface{} {
return s.trie.Root
}
|
