plugeth/core/execution.go
Jeffrey Wilcke 184e9ae9a8 core, tests: reduced state copy by N calls
Reduced the amount of state copied that are required by N calls by doing
a balance check prior to any state modifications.
2015-08-07 12:52:23 +02:00

125 lines
4.0 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 core
import (
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/params"
)
// Execution is the execution environment for the given call or create action.
type Execution struct {
env vm.Environment
address *common.Address
input []byte
evm vm.VirtualMachine
Gas, price, value *big.Int
}
// NewExecution returns a new execution environment that handles all calling
// and creation logic defined by the YP.
func NewExecution(env vm.Environment, address *common.Address, input []byte, gas, gasPrice, value *big.Int) *Execution {
exe := &Execution{env: env, address: address, input: input, Gas: gas, price: gasPrice, value: value}
exe.evm = vm.NewVm(env)
return exe
}
// Call executes within the given context
func (self *Execution) Call(codeAddr common.Address, caller vm.ContextRef) ([]byte, error) {
// Retrieve the executing code
code := self.env.State().GetCode(codeAddr)
return self.exec(&codeAddr, code, caller)
}
// Create creates a new contract and runs the initialisation procedure of the
// contract. This returns the returned code for the contract and is stored
// elsewhere.
func (self *Execution) Create(caller vm.ContextRef) (ret []byte, err error, account *state.StateObject) {
// Input must be nil for create
code := self.input
self.input = nil
ret, err = self.exec(nil, code, caller)
// Here we get an error if we run into maximum stack depth,
// See: https://github.com/ethereum/yellowpaper/pull/131
// and YP definitions for CREATE instruction
if err != nil {
return nil, err, nil
}
account = self.env.State().GetStateObject(*self.address)
return
}
// exec executes the given code and executes within the contextAddr context.
func (self *Execution) exec(contextAddr *common.Address, code []byte, caller vm.ContextRef) (ret []byte, err error) {
env := self.env
evm := self.evm
// Depth check execution. Fail if we're trying to execute above the
// limit.
if env.Depth() > int(params.CallCreateDepth.Int64()) {
caller.ReturnGas(self.Gas, self.price)
return nil, vm.DepthError
}
if !env.CanTransfer(env.State().GetStateObject(caller.Address()), self.value) {
caller.ReturnGas(self.Gas, self.price)
return nil, ValueTransferErr("insufficient funds to transfer value. Req %v, has %v", self.value, env.State().GetBalance(caller.Address()))
}
var createAccount bool
if self.address == nil {
// Generate a new address
nonce := env.State().GetNonce(caller.Address())
env.State().SetNonce(caller.Address(), nonce+1)
addr := crypto.CreateAddress(caller.Address(), nonce)
self.address = &addr
createAccount = true
}
snapshot := env.State().Copy()
var (
from = env.State().GetStateObject(caller.Address())
to *state.StateObject
)
if createAccount {
to = env.State().CreateAccount(*self.address)
} else {
to = env.State().GetOrNewStateObject(*self.address)
}
vm.Transfer(from, to, self.value)
context := vm.NewContext(caller, to, self.value, self.Gas, self.price)
context.SetCallCode(contextAddr, code)
ret, err = evm.Run(context, self.input)
if err != nil {
env.State().Set(snapshot)
}
return
}