mirror of https://github.com/status-im/op-geth.git
98 lines
3.5 KiB
Go
98 lines
3.5 KiB
Go
// 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/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/consensus"
|
|
"github.com/ethereum/go-ethereum/core/types"
|
|
"github.com/ethereum/go-ethereum/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).Set(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 wether 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)
|
|
}
|