solidity/GasMeter.h
2015-05-06 10:43:59 +02:00

68 lines
1.7 KiB
C++

/*
This file is part of cpp-ethereum.
cpp-ethereum is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
cpp-ethereum 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file GasMeter.cpp
* @author Christian <c@ethdev.com>
* @date 2015
*/
#pragma once
#include <ostream>
#include <libevmasm/AssemblyItem.h>
namespace dev
{
namespace eth
{
/**
* Class that helps computing the maximum gas consumption for instructions.
*/
class GasMeter
{
public:
struct GasConsumption
{
GasConsumption(u256 _value = 0, bool _infinite = false): value(_value), isInfinite(_infinite) {}
static GasConsumption infinite() { return GasConsumption(0, true); }
GasConsumption& operator+=(GasConsumption const& _otherS);
std::ostream& operator<<(std::ostream& _str) const;
u256 value;
bool isInfinite;
};
/// Returns an upper bound on the gas consumed by the given instruction.
GasConsumption estimateMax(AssemblyItem const& _item);
private:
static GasConsumption runGas(Instruction _instruction);
};
inline std::ostream& operator<<(std::ostream& _str, GasMeter::GasConsumption const& _consumption)
{
if (_consumption.isInfinite)
return _str << "inf";
else
return _str << _consumption.value;
}
}
}