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
|
// 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 state
import (
"bytes"
"fmt"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
)
// NodeIterator is an iterator to traverse the entire state trie post-order,
// including all of the contract code and contract state tries.
type NodeIterator struct {
state *StateDB // State being iterated
stateIt *trie.NodeIterator // Primary iterator for the global state trie
dataIt *trie.NodeIterator // Secondary iterator for the data trie of a contract
accountHash common.Hash // Hash of the node containing the account
codeHash common.Hash // Hash of the contract source code
code []byte // Source code associated with a contract
Hash common.Hash // Hash of the current entry being iterated (nil if not standalone)
Entry interface{} // Current state entry being iterated (internal representation)
Parent common.Hash // Hash of the first full ancestor node (nil if current is the root)
}
// NewNodeIterator creates an post-order state node iterator.
func NewNodeIterator(state *StateDB) *NodeIterator {
return &NodeIterator{
state: state,
}
}
// Next moves the iterator to the next node, returning whether there are any
// further nodes.
func (it *NodeIterator) Next() bool {
it.step()
return it.retrieve()
}
// step moves the iterator to the next entry of the state trie.
func (it *NodeIterator) step() {
// Abort if we reached the end of the iteration
if it.state == nil {
return
}
// Initialize the iterator if we've just started
if it.stateIt == nil {
it.stateIt = trie.NewNodeIterator(it.state.trie.Trie)
}
// If we had data nodes previously, we surely have at least state nodes
if it.dataIt != nil {
if cont := it.dataIt.Next(); !cont {
it.dataIt = nil
}
return
}
// If we had source code previously, discard that
if it.code != nil {
it.code = nil
return
}
// Step to the next state trie node, terminating if we're out of nodes
if cont := it.stateIt.Next(); !cont {
it.state, it.stateIt = nil, nil
return
}
// If the state trie node is an internal entry, leave as is
if !it.stateIt.Leaf {
return
}
// Otherwise we've reached an account node, initiate data iteration
var account struct {
Nonce uint64
Balance *big.Int
Root common.Hash
CodeHash []byte
}
err := rlp.Decode(bytes.NewReader(it.stateIt.LeafBlob), &account)
if err != nil {
panic(err)
}
dataTrie, err := trie.New(account.Root, it.state.db)
if err != nil {
panic(err)
}
it.dataIt = trie.NewNodeIterator(dataTrie)
if !it.dataIt.Next() {
it.dataIt = nil
}
if bytes.Compare(account.CodeHash, emptyCodeHash) != 0 {
it.codeHash = common.BytesToHash(account.CodeHash)
it.code, err = it.state.db.Get(account.CodeHash)
if err != nil {
panic(fmt.Sprintf("code %x: %v", account.CodeHash, err))
}
}
it.accountHash = it.stateIt.Parent
}
// retrieve pulls and caches the current state entry the iterator is traversing.
// The method returns whether there are any more data left for inspection.
func (it *NodeIterator) retrieve() bool {
// Clear out any previously set values
it.Hash, it.Entry = common.Hash{}, nil
// If the iteration's done, return no available data
if it.state == nil {
return false
}
// Otherwise retrieve the current entry
switch {
case it.dataIt != nil:
it.Hash, it.Entry, it.Parent = it.dataIt.Hash, it.dataIt.Node, it.dataIt.Parent
if it.Parent == (common.Hash{}) {
it.Parent = it.accountHash
}
case it.code != nil:
it.Hash, it.Entry, it.Parent = it.codeHash, it.code, it.accountHash
case it.stateIt != nil:
it.Hash, it.Entry, it.Parent = it.stateIt.Hash, it.stateIt.Node, it.stateIt.Parent
}
return true
}
|