github.com/klaytn/klaytn@v1.12.1/reward/staking_info_cache.go (about)

     1  // Copyright 2019 The klaytn Authors
     2  // This file is part of the klaytn library.
     3  //
     4  // The klaytn library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The klaytn library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the klaytn library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package reward
    18  
    19  import "sync"
    20  
    21  const (
    22  	maxStakingCache = 4
    23  )
    24  
    25  type stakingInfoCache struct {
    26  	cells       map[uint64]*StakingInfo
    27  	minBlockNum uint64
    28  	lock        sync.RWMutex
    29  }
    30  
    31  func newStakingInfoCache() *stakingInfoCache {
    32  	stakingCache := new(stakingInfoCache)
    33  	stakingCache.cells = make(map[uint64]*StakingInfo)
    34  	return stakingCache
    35  }
    36  
    37  func (sc *stakingInfoCache) get(blockNum uint64) *StakingInfo {
    38  	sc.lock.RLock()
    39  	defer sc.lock.RUnlock()
    40  
    41  	if s, ok := sc.cells[blockNum]; ok {
    42  		return s
    43  	}
    44  	return nil
    45  }
    46  
    47  func (sc *stakingInfoCache) add(stakingInfo *StakingInfo) {
    48  	sc.lock.Lock()
    49  	defer sc.lock.Unlock()
    50  
    51  	// Assumption: stakingInfo is not nil.
    52  
    53  	if _, ok := sc.cells[stakingInfo.BlockNum]; ok {
    54  		return
    55  	}
    56  
    57  	if len(sc.cells) >= maxStakingCache {
    58  		delete(sc.cells, sc.minBlockNum)
    59  	}
    60  	sc.minBlockNum = stakingInfo.BlockNum
    61  	for _, s := range sc.cells {
    62  		if s.BlockNum < sc.minBlockNum {
    63  			sc.minBlockNum = s.BlockNum
    64  		}
    65  	}
    66  	sc.cells[stakingInfo.BlockNum] = stakingInfo
    67  	logger.Debug("Add a new stakingInfo to stakingInfoCache", "blockNum", stakingInfo.BlockNum)
    68  }
    69  
    70  func (sc *stakingInfoCache) purge() {
    71  	sc.lock.Lock()
    72  	defer sc.lock.Unlock()
    73  
    74  	sc.minBlockNum = 0
    75  	sc.cells = make(map[uint64]*StakingInfo)
    76  	logger.Debug("Initialized staking info cache")
    77  }