1 files changed, 246 insertions, 0 deletions
diff --git a/core/vm/gas_table.go b/core/vm/gas_table.go
new file mode 100644
index 000000000..4d2c4e94a
--- /dev/null
+++ b/core/vm/gas_table.go
@@ -0,0 +1,246 @@
+package vm
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+func memoryGasCost(mem *Memory, newMemSize *big.Int) *big.Int {
+	gas := new(big.Int)
+	if newMemSize.Cmp(common.Big0) > 0 {
+		newMemSizeWords := toWordSize(newMemSize)
+
+		if newMemSize.Cmp(u256(int64(mem.Len()))) > 0 {
+			// be careful reusing variables here when changing.
+			// The order has been optimised to reduce allocation
+			oldSize := toWordSize(big.NewInt(int64(mem.Len())))
+			pow := new(big.Int).Exp(oldSize, common.Big2, Zero)
+			linCoef := oldSize.Mul(oldSize, params.MemoryGas)
+			quadCoef := new(big.Int).Div(pow, params.QuadCoeffDiv)
+			oldTotalFee := new(big.Int).Add(linCoef, quadCoef)
+
+			pow.Exp(newMemSizeWords, common.Big2, Zero)
+			linCoef = linCoef.Mul(newMemSizeWords, params.MemoryGas)
+			quadCoef = quadCoef.Div(pow, params.QuadCoeffDiv)
+			newTotalFee := linCoef.Add(linCoef, quadCoef)
+
+			fee := newTotalFee.Sub(newTotalFee, oldTotalFee)
+			gas.Add(gas, fee)
+		}
+	}
+	return gas
+}
+
+func constGasFunc(gas *big.Int) gasFunc {
+	return func(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+		return gas
+	}
+}
+
+func gasCalldataCopy(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := memoryGasCost(mem, memorySize)
+	gas.Add(gas, GasFastestStep)
+	words := toWordSize(stack.Back(2))
+
+	return gas.Add(gas, words.Mul(words, params.CopyGas))
+}
+
+func gasSStore(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	var (
+		y, x = stack.Back(1), stack.Back(0)
+		val  = env.StateDB.GetState(contract.Address(), common.BigToHash(x))
+	)
+	// This checks for 3 scenario's and calculates gas accordingly
+	// 1. From a zero-value address to a non-zero value         (NEW VALUE)
+	// 2. From a non-zero value address to a zero-value address (DELETE)
+	// 3. From a non-zero to a non-zero                         (CHANGE)
+	if common.EmptyHash(val) && !common.EmptyHash(common.BigToHash(y)) {
+		// 0 => non 0
+		return new(big.Int).Set(params.SstoreSetGas)
+	} else if !common.EmptyHash(val) && common.EmptyHash(common.BigToHash(y)) {
+		env.StateDB.AddRefund(params.SstoreRefundGas)
+
+		return new(big.Int).Set(params.SstoreClearGas)
+	} else {
+		// non 0 => non 0 (or 0 => 0)
+		return new(big.Int).Set(params.SstoreResetGas)
+	}
+}
+
+func makeGasLog(n uint) gasFunc {
+	return func(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+		mSize := stack.Back(1)
+
+		gas := new(big.Int).Add(memoryGasCost(mem, memorySize), params.LogGas)
+		gas.Add(gas, new(big.Int).Mul(big.NewInt(int64(n)), params.LogTopicGas))
+		gas.Add(gas, new(big.Int).Mul(mSize, params.LogDataGas))
+		return gas
+	}
+}
+
+func gasSha3(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := memoryGasCost(mem, memorySize)
+	gas.Add(gas, params.Sha3Gas)
+	words := toWordSize(stack.Back(1))
+	return gas.Add(gas, words.Mul(words, params.Sha3WordGas))
+}
+
+func gasCodeCopy(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := memoryGasCost(mem, memorySize)
+	gas.Add(gas, GasFastestStep)
+	words := toWordSize(stack.Back(2))
+
+	return gas.Add(gas, words.Mul(words, params.CopyGas))
+}
+
+func gasExtCodeCopy(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := memoryGasCost(mem, memorySize)
+	gas.Add(gas, gt.ExtcodeCopy)
+	words := toWordSize(stack.Back(3))
+
+	return gas.Add(gas, words.Mul(words, params.CopyGas))
+}
+
+func gasMLoad(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return new(big.Int).Add(GasFastestStep, memoryGasCost(mem, memorySize))
+}
+
+func gasMStore8(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return new(big.Int).Add(GasFastestStep, memoryGasCost(mem, memorySize))
+}
+
+func gasMStore(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return new(big.Int).Add(GasFastestStep, memoryGasCost(mem, memorySize))
+}
+
+func gasCreate(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return new(big.Int).Add(params.CreateGas, memoryGasCost(mem, memorySize))
+}
+
+func gasBalance(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return gt.Balance
+}
+
+func gasExtCodeSize(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return gt.ExtcodeSize
+}
+
+func gasSLoad(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return gt.SLoad
+}
+
+func gasExp(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	expByteLen := int64((stack.data[stack.len()-2].BitLen() + 7) / 8)
+	gas := big.NewInt(expByteLen)
+	gas.Mul(gas, gt.ExpByte)
+	return gas.Add(gas, GasSlowStep)
+}
+
+func gasCall(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := new(big.Int).Set(gt.Calls)
+
+	transfersValue := stack.Back(2).BitLen() > 0
+	var (
+		address = common.BigToAddress(stack.Back(1))
+		eip158  = env.ChainConfig().IsEIP158(env.BlockNumber)
+	)
+	if eip158 {
+		if env.StateDB.Empty(address) && transfersValue {
+			gas.Add(gas, params.CallNewAccountGas)
+		}
+	} else if !env.StateDB.Exist(address) {
+		gas.Add(gas, params.CallNewAccountGas)
+	}
+	if transfersValue {
+		gas.Add(gas, params.CallValueTransferGas)
+	}
+	gas.Add(gas, memoryGasCost(mem, memorySize))
+
+	cg := callGas(gt, contract.Gas, gas, stack.data[stack.len()-1])
+	// Replace the stack item with the new gas calculation. This means that
+	// either the original item is left on the stack or the item is replaced by:
+	// (availableGas - gas) * 63 / 64
+	// We replace the stack item so that it's available when the opCall instruction is
+	// called. This information is otherwise lost due to the dependency on *current*
+	// available gas.
+	stack.data[stack.len()-1] = cg
+
+	return gas.Add(gas, cg)
+}
+
+func gasCallCode(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := new(big.Int).Set(gt.Calls)
+	if stack.Back(2).BitLen() > 0 {
+		gas.Add(gas, params.CallValueTransferGas)
+	}
+	gas.Add(gas, memoryGasCost(mem, memorySize))
+
+	cg := callGas(gt, contract.Gas, gas, stack.data[stack.len()-1])
+	// Replace the stack item with the new gas calculation. This means that
+	// either the original item is left on the stack or the item is replaced by:
+	// (availableGas - gas) * 63 / 64
+	// We replace the stack item so that it's available when the opCall instruction is
+	// called. This information is otherwise lost due to the dependency on *current*
+	// available gas.
+	stack.data[stack.len()-1] = cg
+
+	return gas.Add(gas, cg)
+}
+
+func gasReturn(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return memoryGasCost(mem, memorySize)
+}
+
+func gasSuicide(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := new(big.Int)
+	// EIP150 homestead gas reprice fork:
+	if env.ChainConfig().IsEIP150(env.BlockNumber) {
+		gas.Set(gt.Suicide)
+		var (
+			address = common.BigToAddress(stack.Back(0))
+			eip158  = env.ChainConfig().IsEIP158(env.BlockNumber)
+		)
+
+		if eip158 {
+			// if empty and transfers value
+			if env.StateDB.Empty(address) && env.StateDB.GetBalance(contract.Address()).BitLen() > 0 {
+				gas.Add(gas, gt.CreateBySuicide)
+			}
+		} else if !env.StateDB.Exist(address) {
+			gas.Add(gas, gt.CreateBySuicide)
+		}
+	}
+
+	if !env.StateDB.HasSuicided(contract.Address()) {
+		env.StateDB.AddRefund(params.SuicideRefundGas)
+	}
+	return gas
+}
+
+func gasDelegateCall(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := new(big.Int).Add(gt.Calls, memoryGasCost(mem, memorySize))
+
+	cg := callGas(gt, contract.Gas, gas, stack.data[stack.len()-1])
+	// Replace the stack item with the new gas calculation. This means that
+	// either the original item is left on the stack or the item is replaced by:
+	// (availableGas - gas) * 63 / 64
+	// We replace the stack item so that it's available when the opCall instruction is
+	// called.
+	stack.data[stack.len()-1] = cg
+
+	return gas.Add(gas, cg)
+}
+
+func gasPush(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return GasFastestStep
+}
+
+func gasSwap(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return GasFastestStep
+}
+
+func gasDup(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return GasFastestStep
+}