-
Notifications
You must be signed in to change notification settings - Fork 0
/
evm.go
97 lines (87 loc) · 3.54 KB
/
evm.go
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
// 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 core
import (
"math/big"
"github.com/clanetcnc/go-clanetdiuma/common"
"github.com/clanetcnc/go-clanetdiuma/consensus"
"github.com/clanetcnc/go-clanetdiuma/core/types"
"github.com/clanetcnc/go-clanetdiuma/core/vm"
)
// ChainContext supports retrieving headers and consensus parameters from the
// current blockchain to be used during transaction processing.
type ChainContext interface {
// Engine retrieves the chain's consensus engine.
Engine() consensus.Engine
// GetHeader returns the hash corresponding to their hash.
GetHeader(common.Hash, uint64) *types.Header
}
// NewEVMContext creates a new context for use in the EVM.
func NewEVMContext(msg Message, header *types.Header, chain ChainContext, author *common.Address) vm.Context {
// If we don't have an explicit author (i.e. not mining), extract from the header
var beneficiary common.Address
if author == nil {
beneficiary, _ = chain.Engine().Author(header) // Ignore error, we're past header validation
} else {
beneficiary = *author
}
return vm.Context{
CanTransfer: CanTransfer,
Transfer: Transfer,
GetHash: GetHashFn(header, chain),
Origin: msg.From(),
Coinbase: beneficiary,
BlockNumber: new(big.Int).Set(header.Number),
Time: new(big.Int).SetUint64(header.Time),
Difficulty: new(big.Int).Set(header.Difficulty),
GasLimit: header.GasLimit,
GasPrice: new(big.Int).Set(msg.GasPrice()),
}
}
// GetHashFn returns a GetHashFunc which retrieves header hashes by number
func GetHashFn(ref *types.Header, chain ChainContext) func(n uint64) common.Hash {
var cache map[uint64]common.Hash
return func(n uint64) common.Hash {
// If there's no hash cache yet, make one
if cache == nil {
cache = map[uint64]common.Hash{
ref.Number.Uint64() - 1: ref.ParentHash,
}
}
// Try to fulfill the request from the cache
if hash, ok := cache[n]; ok {
return hash
}
// Not cached, iterate the blocks and cache the hashes
for header := chain.GetHeader(ref.ParentHash, ref.Number.Uint64()-1); header != nil; header = chain.GetHeader(header.ParentHash, header.Number.Uint64()-1) {
cache[header.Number.Uint64()-1] = header.ParentHash
if n == header.Number.Uint64()-1 {
return header.ParentHash
}
}
return common.Hash{}
}
}
// CanTransfer checks whether there are enough funds in the address' account to make a transfer.
// This does not take the necessary gas in to account to make the transfer valid.
func CanTransfer(db vm.StateDB, addr common.Address, amount *big.Int) bool {
return db.GetBalance(addr).Cmp(amount) >= 0
}
// Transfer subtracts amount from sender and adds amount to recipient using the given Db
func Transfer(db vm.StateDB, sender, recipient common.Address, amount *big.Int) {
db.SubBalance(sender, amount)
db.AddBalance(recipient, amount)
}