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
// Copyright 2016 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"
"context"
"errors"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/rlp"
)
var sha3_nil = crypto.Keccak256Hash(nil)
var (
ErrNoTrustedCht = errors.New("No trusted canonical hash trie")
ErrNoHeader = errors.New("Header not found")
ChtFrequency = uint64(4096)
ChtConfirmations = uint64(2048)
trustedChtKey = []byte("TrustedCHT")
)
type ChtNode struct {
Hash common.Hash
Td *big.Int
}
type TrustedCht struct {
Number uint64
Root common.Hash
}
func GetTrustedCht(db ethdb.Database) TrustedCht {
data, _ := db.Get(trustedChtKey)
var res TrustedCht
if err := rlp.DecodeBytes(data, &res); err != nil {
return TrustedCht{0, common.Hash{}}
}
return res
}
func WriteTrustedCht(db ethdb.Database, cht TrustedCht) {
data, _ := rlp.EncodeToBytes(cht)
db.Put(trustedChtKey, data)
}
func DeleteTrustedCht(db ethdb.Database) {
db.Delete(trustedChtKey)
}
func GetHeaderByNumber(ctx context.Context, odr OdrBackend, number uint64) (*types.Header, error) {
db := odr.Database()
hash := core.GetCanonicalHash(db, number)
if (hash != common.Hash{}) {
// if there is a canonical hash, there is a header too
header := core.GetHeader(db, hash, number)
if header == nil {
panic("Canonical hash present but header not found")
}
return header, nil
}
cht := GetTrustedCht(db)
if number >= cht.Number*ChtFrequency {
return nil, ErrNoTrustedCht
}
r := &ChtRequest{ChtRoot: cht.Root, ChtNum: cht.Number, BlockNum: number}
if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
} else {
return r.Header, nil
}
}
func GetCanonicalHash(ctx context.Context, odr OdrBackend, number uint64) (common.Hash, error) {
hash := core.GetCanonicalHash(odr.Database(), number)
if (hash != common.Hash{}) {
return hash, nil
}
header, err := GetHeaderByNumber(ctx, odr, number)
if header != nil {
return header.Hash(), nil
}
return common.Hash{}, err
}
// retrieveContractCode tries to retrieve the contract code of the given account
// with the given hash from the network (id points to the storage trie belonging
// to the same account)
func retrieveContractCode(ctx context.Context, odr OdrBackend, id *TrieID, hash common.Hash) ([]byte, error) {
if hash == sha3_nil {
return nil, nil
}
res, _ := odr.Database().Get(hash[:])
if res != nil {
return res, nil
}
r := &CodeRequest{Id: id, Hash: hash}
if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
} else {
return r.Data, nil
}
}
// GetBodyRLP retrieves the block body (transactions and uncles) in RLP encoding.
func GetBodyRLP(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) (rlp.RawValue, error) {
if data := core.GetBodyRLP(odr.Database(), hash, number); data != nil {
return data, nil
}
r := &BlockRequest{Hash: hash, Number: number}
if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
} else {
return r.Rlp, nil
}
}
// GetBody retrieves the block body (transactons, uncles) corresponding to the
// hash.
func GetBody(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) (*types.Body, error) {
data, err := GetBodyRLP(ctx, odr, hash, number)
if err != nil {
return nil, err
}
body := new(types.Body)
if err := rlp.Decode(bytes.NewReader(data), body); err != nil {
return nil, err
}
return body, nil
}
// GetBlock retrieves an entire block corresponding to the hash, assembling it
// back from the stored header and body.
func GetBlock(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) (*types.Block, error) {
// Retrieve the block header and body contents
header := core.GetHeader(odr.Database(), hash, number)
if header == nil {
return nil, ErrNoHeader
}
body, err := GetBody(ctx, odr, hash, number)
if err != nil {
return nil, err
}
// Reassemble the block and return
return types.NewBlockWithHeader(header).WithBody(body.Transactions, body.Uncles), nil
}
// GetBlockReceipts retrieves the receipts generated by the transactions included
// in a block given by its hash.
func GetBlockReceipts(ctx context.Context, odr OdrBackend, hash common.Hash, number uint64) (types.Receipts, error) {
receipts := core.GetBlockReceipts(odr.Database(), hash, number)
if receipts != nil {
return receipts, nil
}
r := &ReceiptsRequest{Hash: hash, Number: number}
if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
}
return r.Receipts, nil
}