func getData(data []byte, start, size *big.Int) []byte { dlen := big.NewInt(int64(len(data))) s := common.BigMin(start, dlen) e := common.BigMin(new(big.Int).Add(s, size), dlen) return common.RightPadBytes(data[s.Uint64():e.Uint64()], int(size.Uint64())) }
// CalcGasLimit computes the gas limit of the next block after parent. // The result may be modified by the caller. // This is miner strategy, not consensus protocol. func CalcGasLimit(parent *types.Block) *big.Int { // contrib = (parentGasUsed * 3 / 2) / 1024 contrib := new(big.Int).Mul(parent.GasUsed(), big.NewInt(3)) contrib = contrib.Div(contrib, big.NewInt(2)) contrib = contrib.Div(contrib, params.GasLimitBoundDivisor) // decay = parentGasLimit / 1024 -1 decay := new(big.Int).Div(parent.GasLimit(), params.GasLimitBoundDivisor) decay.Sub(decay, big.NewInt(1)) /* strategy: gasLimit of block-to-mine is set based on parent's gasUsed value. if parentGasUsed > parentGasLimit * (2/3) then we increase it, otherwise lower it (or leave it unchanged if it's right at that usage) the amount increased/decreased depends on how far away from parentGasLimit * (2/3) parentGasUsed is. */ gl := new(big.Int).Sub(parent.GasLimit(), decay) gl = gl.Add(gl, contrib) gl.Set(common.BigMax(gl, params.MinGasLimit)) // however, if we're now below the target (TargetGasLimit) we increase the // limit as much as we can (parentGasLimit / 1024 -1) if gl.Cmp(params.TargetGasLimit) < 0 { gl.Add(parent.GasLimit(), decay) gl.Set(common.BigMin(gl, params.TargetGasLimit)) } return gl }
func (self *StateTransition) refundGas() { sender, _ := self.From() // err already checked // Return remaining gas remaining := new(big.Int).Mul(self.gas, self.gasPrice) sender.AddBalance(remaining) uhalf := remaining.Div(self.gasUsed(), common.Big2) refund := common.BigMin(uhalf, self.state.Refunds()) self.gas.Add(self.gas, refund) self.state.AddBalance(sender.Address(), refund.Mul(refund, self.gasPrice)) self.gp.AddGas(self.gas, self.gasPrice) }
func (self *StateTransition) refundGas() { coinbase, sender := self.Coinbase(), self.From() // Return remaining gas remaining := new(big.Int).Mul(self.gas, self.msg.GasPrice()) sender.AddBalance(remaining) uhalf := new(big.Int).Div(self.gasUsed(), common.Big2) for addr, ref := range self.state.Refunds() { refund := common.BigMin(uhalf, ref) self.gas.Add(self.gas, refund) self.state.AddBalance(common.StringToAddress(addr), refund.Mul(refund, self.msg.GasPrice())) } coinbase.RefundGas(self.gas, self.msg.GasPrice()) }
func (self *StateTransition) refundGas() { // Return eth for remaining gas to the sender account, // exchanged at the original rate. sender, _ := self.from() // err already checked remaining := new(big.Int).Mul(self.gas, self.gasPrice) sender.AddBalance(remaining) // Apply refund counter, capped to half of the used gas. uhalf := remaining.Div(self.gasUsed(), common.Big2) refund := common.BigMin(uhalf, self.state.GetRefund()) self.gas.Add(self.gas, refund) self.state.AddBalance(sender.Address(), refund.Mul(refund, self.gasPrice)) // Also return remaining gas to the block gas counter so it is // available for the next transaction. self.gp.AddGas(self.gas) }
// CalcGasLimit computes the gas limit of the next block after parent. // The result may be modified by the caller. func CalcGasLimit(parent *types.Block) *big.Int { decay := new(big.Int).Div(parent.GasLimit(), params.GasLimitBoundDivisor) contrib := new(big.Int).Mul(parent.GasUsed(), big.NewInt(3)) contrib = contrib.Div(contrib, big.NewInt(2)) contrib = contrib.Div(contrib, params.GasLimitBoundDivisor) gl := new(big.Int).Sub(parent.GasLimit(), decay) gl = gl.Add(gl, contrib) gl = gl.Add(gl, big.NewInt(1)) gl.Set(common.BigMax(gl, params.MinGasLimit)) if gl.Cmp(params.GenesisGasLimit) < 0 { gl.Add(parent.GasLimit(), decay) gl.Set(common.BigMin(gl, params.GenesisGasLimit)) } return gl }