plugeth/core/vm/interface.go
Jeffrey Wilcke bbc4ea4ae8 core/vm: improved EVM run loop & instruction calling (#3378)
The run loop, which previously contained custom opcode executes have been
removed and has been simplified to a few checks.

Each operation consists of 4 elements: execution function, gas cost function,
stack validation function and memory size function. The execution function
implements the operation's runtime behaviour, the gas cost function implements
the operation gas costs function and greatly depends on the memory and stack,
the stack validation function validates the stack and makes sure that enough
items can be popped off and pushed on and the memory size function calculates
the memory required for the operation and returns it.

This commit also allows the EVM to go unmetered. This is helpful for offline
operations such as contract calls.
2017-01-05 11:52:10 +01:00

90 lines
3.0 KiB
Go

// Copyright 2014 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 vm
import (
"math/big"
"github.com/ethereum/go-ethereum/common"
)
// StateDB is an EVM database for full state querying.
type StateDB interface {
GetAccount(common.Address) Account
CreateAccount(common.Address) Account
SubBalance(common.Address, *big.Int)
AddBalance(common.Address, *big.Int)
GetBalance(common.Address) *big.Int
GetNonce(common.Address) uint64
SetNonce(common.Address, uint64)
GetCodeHash(common.Address) common.Hash
GetCode(common.Address) []byte
SetCode(common.Address, []byte)
GetCodeSize(common.Address) int
AddRefund(*big.Int)
GetRefund() *big.Int
GetState(common.Address, common.Hash) common.Hash
SetState(common.Address, common.Hash, common.Hash)
Suicide(common.Address) bool
HasSuicided(common.Address) bool
// Exist reports whether the given account exists in state.
// Notably this should also return true for suicided accounts.
Exist(common.Address) bool
// Empty returns whether the given account is empty. Empty
// is defined according to EIP161 (balance = nonce = code = 0).
Empty(common.Address) bool
RevertToSnapshot(int)
Snapshot() int
AddLog(*Log)
}
// Account represents a contract or basic ethereum account.
type Account interface {
SubBalance(amount *big.Int)
AddBalance(amount *big.Int)
SetBalance(*big.Int)
SetNonce(uint64)
Balance() *big.Int
Address() common.Address
ReturnGas(*big.Int)
SetCode(common.Hash, []byte)
ForEachStorage(cb func(key, value common.Hash) bool)
Value() *big.Int
}
// CallContext provides a basic interface for the EVM calling conventions. The EVM EVM
// depends on this context being implemented for doing subcalls and initialising new EVM contracts.
type CallContext interface {
// Call another contract
Call(env *EVM, me ContractRef, addr common.Address, data []byte, gas, value *big.Int) ([]byte, error)
// Take another's contract code and execute within our own context
CallCode(env *EVM, me ContractRef, addr common.Address, data []byte, gas, value *big.Int) ([]byte, error)
// Same as CallCode except sender and value is propagated from parent to child scope
DelegateCall(env *EVM, me ContractRef, addr common.Address, data []byte, gas *big.Int) ([]byte, error)
// Create a new contract
Create(env *EVM, me ContractRef, data []byte, gas, value *big.Int) ([]byte, common.Address, error)
}