github.com/klaytn/klaytn@v1.12.1/blockchain/gaspool.go (about)

     1  // Modifications Copyright 2018 The klaytn Authors
     2  // Copyright 2015 The go-ethereum Authors
     3  // This file is part of the go-ethereum library.
     4  //
     5  // The go-ethereum library is free software: you can redistribute it and/or modify
     6  // it under the terms of the GNU Lesser General Public License as published by
     7  // the Free Software Foundation, either version 3 of the License, or
     8  // (at your option) any later version.
     9  //
    10  // The go-ethereum library is distributed in the hope that it will be useful,
    11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  // GNU Lesser General Public License for more details.
    14  //
    15  // You should have received a copy of the GNU Lesser General Public License
    16  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    17  //
    18  // This file is derived from core/gaspool.go (2018/06/04).
    19  // Modified and improved for the klaytn development.
    20  
    21  package blockchain
    22  
    23  import (
    24  	"fmt"
    25  	"math"
    26  )
    27  
    28  // GasPool tracks the amount of gas available during execution of the transactions
    29  // in a block. The zero value is a pool with zero gas available.
    30  type GasPool uint64
    31  
    32  // AddGas makes gas available for execution.
    33  func (gp *GasPool) AddGas(amount uint64) *GasPool {
    34  	if uint64(*gp) > math.MaxUint64-amount {
    35  		panic("gas pool pushed above uint64")
    36  	}
    37  	*(*uint64)(gp) += amount
    38  	return gp
    39  }
    40  
    41  // SubGas deducts the given amount from the pool if enough gas is
    42  // available and returns an error otherwise.
    43  func (gp *GasPool) SubGas(amount uint64) error {
    44  	if uint64(*gp) < amount {
    45  		return ErrGasLimitReached
    46  	}
    47  	*(*uint64)(gp) -= amount
    48  	return nil
    49  }
    50  
    51  // Gas returns the amount of gas remaining in the pool.
    52  func (gp *GasPool) Gas() uint64 {
    53  	return uint64(*gp)
    54  }
    55  
    56  func (gp *GasPool) String() string {
    57  	return fmt.Sprintf("%d", *gp)
    58  }