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
package l2
import (
"fmt"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum-optimism/optimism/op-node/eth"
"github.com/ethereum-optimism/optimism/op-program/client/mpt"
"github.com/ethereum-optimism/optimism/op-program/preimage"
)
// StateOracle defines the high-level API used to retrieve L2 state data pre-images
// The returned data is always the preimage of the requested hash.
type StateOracle interface {
// NodeByHash retrieves the merkle-patricia trie node pre-image for a given hash.
// Trie nodes may be from the world state trie or any account storage trie.
// Contract code is not stored as part of the trie and must be retrieved via CodeByHash
NodeByHash(nodeHash common.Hash) []byte
// CodeByHash retrieves the contract code pre-image for a given hash.
// codeHash should be retrieved from the world state account for a contract.
CodeByHash(codeHash common.Hash) []byte
}
// Oracle defines the high-level API used to retrieve L2 data.
// The returned data is always the preimage of the requested hash.
type Oracle interface {
StateOracle
// BlockByHash retrieves the block with the given hash.
BlockByHash(blockHash common.Hash) *types.Block
}
// PreimageOracle implements Oracle using by interfacing with the pure preimage.Oracle
// to fetch pre-images to decode into the requested data.
type PreimageOracle struct {
oracle preimage.Oracle
hint preimage.Hinter
}
var _ Oracle = (*PreimageOracle)(nil)
func NewPreimageOracle(raw preimage.Oracle, hint preimage.Hinter) *PreimageOracle {
return &PreimageOracle{
oracle: raw,
hint: hint,
}
}
func (p *PreimageOracle) headerByBlockHash(blockHash common.Hash) *types.Header {
p.hint.Hint(BlockHeaderHint(blockHash))
headerRlp := p.oracle.Get(preimage.Keccak256Key(blockHash))
var header types.Header
if err := rlp.DecodeBytes(headerRlp, &header); err != nil {
panic(fmt.Errorf("invalid block header %s: %w", blockHash, err))
}
return &header
}
func (p *PreimageOracle) BlockByHash(blockHash common.Hash) *types.Block {
header := p.headerByBlockHash(blockHash)
p.hint.Hint(TransactionsHint(blockHash))
opaqueTxs := mpt.ReadTrie(header.TxHash, func(key common.Hash) []byte {
return p.oracle.Get(preimage.Keccak256Key(key))
})
txs, err := eth.DecodeTransactions(opaqueTxs)
if err != nil {
panic(fmt.Errorf("failed to decode list of txs: %w", err))
}
return types.NewBlockWithHeader(header).WithBody(txs, nil)
}
func (p *PreimageOracle) NodeByHash(nodeHash common.Hash) []byte {
p.hint.Hint(StateNodeHint(nodeHash))
return p.oracle.Get(preimage.Keccak256Key(nodeHash))
}
func (p *PreimageOracle) CodeByHash(codeHash common.Hash) []byte {
p.hint.Hint(CodeHint(codeHash))
return p.oracle.Get(preimage.Keccak256Key(codeHash))
}