Reduced the amount of state copied that are required by N calls by doing a balance check prior to any state modifications.
		
			
				
	
	
		
			86 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			86 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
// Copyright 2014 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package vm
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import (
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	"errors"
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	"math/big"
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	"github.com/ethereum/go-ethereum/common"
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	"github.com/ethereum/go-ethereum/core/state"
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)
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// Environment is is required by the virtual machine to get information from
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// it's own isolated environment. For an example see `core.VMEnv`
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type Environment interface {
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	State() *state.StateDB
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	Origin() common.Address
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	BlockNumber() *big.Int
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	GetHash(n uint64) common.Hash
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	Coinbase() common.Address
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	Time() uint64
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	Difficulty() *big.Int
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	GasLimit() *big.Int
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	CanTransfer(from Account, balance *big.Int) bool
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	Transfer(from, to Account, amount *big.Int) error
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	AddLog(*state.Log)
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	AddStructLog(StructLog)
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	StructLogs() []StructLog
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	VmType() Type
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	Depth() int
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	SetDepth(i int)
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	Call(me ContextRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error)
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	CallCode(me ContextRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error)
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	Create(me ContextRef, data []byte, gas, price, value *big.Int) ([]byte, error, ContextRef)
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}
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// StructLog is emited to the Environment each cycle and lists information about the curent internal state
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// prior to the execution of the statement.
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type StructLog struct {
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	Pc      uint64
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	Op      OpCode
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	Gas     *big.Int
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	GasCost *big.Int
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	Memory  []byte
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	Stack   []*big.Int
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	Storage map[common.Hash][]byte
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	Err     error
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}
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type Account interface {
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	SubBalance(amount *big.Int)
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	AddBalance(amount *big.Int)
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	Balance() *big.Int
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	Address() common.Address
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}
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// generic transfer method
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func Transfer(from, to Account, amount *big.Int) error {
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	if from.Balance().Cmp(amount) < 0 {
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		return errors.New("Insufficient balance in account")
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	}
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	from.SubBalance(amount)
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	to.AddBalance(amount)
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	return nil
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}
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