github.com/theQRL/go-zond@v0.2.1/core/vm/gas_table.go

// Copyright 2017 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 (
	"github.com/theQRL/go-zond/common"
	"github.com/theQRL/go-zond/common/math"
	"github.com/theQRL/go-zond/params"
)

// memoryGasCost calculates the quadratic gas for memory expansion. It does so
// only for the memory region that is expanded, not the total memory.
func memoryGasCost(mem *Memory, newMemSize uint64) (uint64, error) {
	if newMemSize == 0 {
		return 0, nil
	}
	// The maximum that will fit in a uint64 is max_word_count - 1. Anything above
	// that will result in an overflow. Additionally, a newMemSize which results in
	// a newMemSizeWords larger than 0xFFFFFFFF will cause the square operation to
	// overflow. The constant 0x1FFFFFFFE0 is the highest number that can be used
	// without overflowing the gas calculation.
	if newMemSize > 0x1FFFFFFFE0 {
		return 0, ErrGasUintOverflow
	}
	newMemSizeWords := toWordSize(newMemSize)
	newMemSize = newMemSizeWords * 32

	if newMemSize > uint64(mem.Len()) {
		square := newMemSizeWords * newMemSizeWords
		linCoef := newMemSizeWords * params.MemoryGas
		quadCoef := square / params.QuadCoeffDiv
		newTotalFee := linCoef + quadCoef

		fee := newTotalFee - mem.lastGasCost
		mem.lastGasCost = newTotalFee

		return fee, nil
	}
	return 0, nil
}

// memoryCopierGas creates the gas functions for the following opcodes, and takes
// the stack position of the operand which determines the size of the data to copy
// as argument:
// CALLDATACOPY (stack position 2)
// CODECOPY (stack position 2)
// EXTCODECOPY (stack position 3)
// RETURNDATACOPY (stack position 2)
func memoryCopierGas(stackpos int) gasFunc {
	return func(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
		// Gas for expanding the memory
		gas, err := memoryGasCost(mem, memorySize)
		if err != nil {
			return 0, err
		}
		// And gas for copying data, charged per word at param.CopyGas
		words, overflow := stack.Back(stackpos).Uint64WithOverflow()
		if overflow {
			return 0, ErrGasUintOverflow
		}

		if words, overflow = math.SafeMul(toWordSize(words), params.CopyGas); overflow {
			return 0, ErrGasUintOverflow
		}

		if gas, overflow = math.SafeAdd(gas, words); overflow {
			return 0, ErrGasUintOverflow
		}
		return gas, nil
	}
}

var (
	gasCallDataCopy   = memoryCopierGas(2)
	gasCodeCopy       = memoryCopierGas(2)
	gasExtCodeCopy    = memoryCopierGas(3)
	gasReturnDataCopy = memoryCopierGas(2)
)

func makeGasLog(n uint64) gasFunc {
	return func(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
		requestedSize, overflow := stack.Back(1).Uint64WithOverflow()
		if overflow {
			return 0, ErrGasUintOverflow
		}

		gas, err := memoryGasCost(mem, memorySize)
		if err != nil {
			return 0, err
		}

		if gas, overflow = math.SafeAdd(gas, params.LogGas); overflow {
			return 0, ErrGasUintOverflow
		}
		if gas, overflow = math.SafeAdd(gas, n*params.LogTopicGas); overflow {
			return 0, ErrGasUintOverflow
		}

		var memorySizeGas uint64
		if memorySizeGas, overflow = math.SafeMul(requestedSize, params.LogDataGas); overflow {
			return 0, ErrGasUintOverflow
		}
		if gas, overflow = math.SafeAdd(gas, memorySizeGas); overflow {
			return 0, ErrGasUintOverflow
		}
		return gas, nil
	}
}

func gasKeccak256(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
	gas, err := memoryGasCost(mem, memorySize)
	if err != nil {
		return 0, err
	}
	wordGas, overflow := stack.Back(1).Uint64WithOverflow()
	if overflow {
		return 0, ErrGasUintOverflow
	}
	if wordGas, overflow = math.SafeMul(toWordSize(wordGas), params.Keccak256WordGas); overflow {
		return 0, ErrGasUintOverflow
	}
	if gas, overflow = math.SafeAdd(gas, wordGas); overflow {
		return 0, ErrGasUintOverflow
	}
	return gas, nil
}

// pureMemoryGascost is used by several operations, which aside from their
// static cost have a dynamic cost which is solely based on the memory
// expansion
func pureMemoryGascost(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
	return memoryGasCost(mem, memorySize)
}

var (
	gasReturn  = pureMemoryGascost
	gasRevert  = pureMemoryGascost
	gasMLoad   = pureMemoryGascost
	gasMStore8 = pureMemoryGascost
	gasMStore  = pureMemoryGascost
)

func gasCreateEip3860(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
	gas, err := memoryGasCost(mem, memorySize)
	if err != nil {
		return 0, err
	}
	size, overflow := stack.Back(2).Uint64WithOverflow()
	if overflow || size > params.MaxInitCodeSize {
		return 0, ErrGasUintOverflow
	}
	// Since size <= params.MaxInitCodeSize, these multiplication cannot overflow
	moreGas := params.InitCodeWordGas * ((size + 31) / 32)
	if gas, overflow = math.SafeAdd(gas, moreGas); overflow {
		return 0, ErrGasUintOverflow
	}
	return gas, nil
}
func gasCreate2Eip3860(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
	gas, err := memoryGasCost(mem, memorySize)
	if err != nil {
		return 0, err
	}
	size, overflow := stack.Back(2).Uint64WithOverflow()
	if overflow || size > params.MaxInitCodeSize {
		return 0, ErrGasUintOverflow
	}
	// Since size <= params.MaxInitCodeSize, these multiplication cannot overflow
	moreGas := (params.InitCodeWordGas + params.Keccak256WordGas) * ((size + 31) / 32)
	if gas, overflow = math.SafeAdd(gas, moreGas); overflow {
		return 0, ErrGasUintOverflow
	}
	return gas, nil
}

func gasExpEIP158(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
	expByteLen := uint64((stack.data[stack.len()-2].BitLen() + 7) / 8)

	var (
		gas      = expByteLen * params.ExpByteEIP158 // no overflow check required. Max is 256 * ExpByte gas
		overflow bool
	)
	if gas, overflow = math.SafeAdd(gas, params.ExpGas); overflow {
		return 0, ErrGasUintOverflow
	}
	return gas, nil
}

func gasCall(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
	var (
		gas            uint64
		transfersValue = !stack.Back(2).IsZero()
		address        = common.Address(stack.Back(1).Bytes20())
	)
	if transfersValue && zvm.StateDB.Empty(address) {
		gas += params.CallNewAccountGas
	}
	if transfersValue {
		gas += params.CallValueTransferGas
	}
	memoryGas, err := memoryGasCost(mem, memorySize)
	if err != nil {
		return 0, err
	}
	var overflow bool
	if gas, overflow = math.SafeAdd(gas, memoryGas); overflow {
		return 0, ErrGasUintOverflow
	}

	zvm.callGasTemp, err = callGas(contract.Gas, gas, stack.Back(0))
	if err != nil {
		return 0, err
	}
	if gas, overflow = math.SafeAdd(gas, zvm.callGasTemp); overflow {
		return 0, ErrGasUintOverflow
	}
	return gas, nil
}

func gasDelegateCall(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
	gas, err := memoryGasCost(mem, memorySize)
	if err != nil {
		return 0, err
	}
	zvm.callGasTemp, err = callGas(contract.Gas, gas, stack.Back(0))
	if err != nil {
		return 0, err
	}
	var overflow bool
	if gas, overflow = math.SafeAdd(gas, zvm.callGasTemp); overflow {
		return 0, ErrGasUintOverflow
	}
	return gas, nil
}

func gasStaticCall(zvm *ZVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
	gas, err := memoryGasCost(mem, memorySize)
	if err != nil {
		return 0, err
	}
	zvm.callGasTemp, err = callGas(contract.Gas, gas, stack.Back(0))
	if err != nil {
		return 0, err
	}
	var overflow bool
	if gas, overflow = math.SafeAdd(gas, zvm.callGasTemp); overflow {
		return 0, ErrGasUintOverflow
	}
	return gas, nil
}