forked from etcd-io/etcd
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
yifeng zhang
committed
Nov 23, 2021
1 parent
72d3e38
commit 58de4de
Showing
8 changed files
with
200 additions
and
14 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,162 @@ | ||
| package mvcc | ||
|
|
||
| import ( | ||
| "fmt" | ||
| "go.etcd.io/etcd/mvcc/mvccpb" | ||
| "math" | ||
| "strconv" | ||
| "sync" | ||
| "time" | ||
| ) | ||
|
|
||
| const ( | ||
| // lfuSample is the number of items to sample when looking at eviction | ||
| // candidates. 5 seems to be the most optimal number. | ||
| lfuSample = 5 | ||
| // default estimator counter size | ||
| defaultEstimatorCapacity = 100 | ||
| // default cache cost upper limit | ||
| defaultCostCapacity = 100 * 1024 * 1024 | ||
| //costThreshold = 1024 * 1024 * 1024 | ||
| ) | ||
|
|
||
| type storeCache struct { | ||
| lock *sync.RWMutex | ||
| costEstimator costEstimator | ||
| cache map[revision]*mvccpb.KeyValue | ||
| currentCost int | ||
| costCapacity int | ||
| lastUpdate time.Time | ||
| cachedReq string | ||
| } | ||
|
|
||
| type costEstimator struct { | ||
| lock *sync.Mutex | ||
| bound int | ||
| counter map[string]int | ||
| maxCostReq string | ||
| } | ||
|
|
||
| func newStoreCache() *storeCache { | ||
| c := new(storeCache) | ||
| c.costEstimator = costEstimator{ | ||
| lock: new(sync.Mutex), | ||
| bound: defaultEstimatorCapacity, | ||
| counter: make(map[string]int), | ||
| } | ||
| c.cache = make(map[revision]*mvccpb.KeyValue) | ||
| c.lock = new(sync.RWMutex) | ||
| c.costCapacity = defaultCostCapacity | ||
| c.lastUpdate = time.Time{} | ||
| return c | ||
| } | ||
|
|
||
| func (c *storeCache) get(key revision) (*mvccpb.KeyValue, bool) { | ||
| c.lock.RLock() | ||
| defer c.lock.RUnlock() | ||
| e, ok := c.cache[key] | ||
| return e, ok | ||
| } | ||
|
|
||
| func (c *storeCache) set(key revision, value *mvccpb.KeyValue, cost int) bool { | ||
| c.lock.Lock() | ||
| defer c.lock.Unlock() | ||
| if _, ok := c.cache[key]; !ok { | ||
| return c.unsafeSet(key, value, cost) | ||
| } | ||
| return true | ||
| } | ||
|
|
||
| func (c *storeCache) unsafeSet(key revision, value *mvccpb.KeyValue, cost int) bool { | ||
| if c.currentCost < c.costCapacity-cost { | ||
| c.cache[key] = value | ||
| c.currentCost += cost | ||
| //fmt.Println("capacity success") | ||
| //fmt.Println(c.currentCost) | ||
| //fmt.Println(cost) | ||
| return true | ||
| } else { | ||
| fmt.Println("capacity full, can't cache") | ||
| fmt.Println(c.currentCost) | ||
| fmt.Println(cost) | ||
| return false | ||
| } | ||
| } | ||
|
|
||
| func (c *storeCache) hasCachedRequest(request string) bool { | ||
| c.lock.RLock() | ||
| defer c.lock.RUnlock() | ||
| return c.cachedReq == request | ||
| } | ||
|
|
||
| func (c *storeCache) updateCacheIfNecessary(request string, cost int, rvs []revision, kvs []*mvccpb.KeyValue) { | ||
| if c.costEstimator.updateRequestCosts(request, cost) { | ||
| c.lock.Lock() | ||
| defer c.lock.Unlock() | ||
| if time.Since(c.lastUpdate) >= 1*time.Minute && request != c.cachedReq { | ||
| c.clear() | ||
| for i, r := range rvs { | ||
| fmt.Println("caching item " + strconv.Itoa(i)) | ||
| if !c.unsafeSet(r, kvs[i], kvs[i].Size()) { | ||
| break | ||
| } | ||
| } | ||
| c.cachedReq = request | ||
| fmt.Println("caching updated " + strconv.Itoa(c.currentCost)) | ||
| } | ||
| } | ||
| } | ||
|
|
||
| func (c *storeCache) clear() { | ||
| c.cache = make(map[revision]*mvccpb.KeyValue) | ||
| c.currentCost = 0 | ||
| c.cachedReq = "" | ||
| c.lastUpdate = time.Now() | ||
| c.costEstimator.clear() | ||
| } | ||
|
|
||
| func (c *costEstimator) updateRequestCosts(request string, cost int) bool { | ||
| c.lock.Lock() | ||
| defer c.lock.Unlock() | ||
| if co, ok := c.counter[request]; ok { | ||
| c.counter[request] = co + cost | ||
| } else { | ||
| if len(c.counter) > c.bound { | ||
| c.evict() | ||
| } | ||
| c.counter[request] = cost | ||
| } | ||
| if c.counter[request] > c.counter[c.maxCostReq] { | ||
| c.maxCostReq = request | ||
| return true | ||
| } | ||
| return false | ||
| } | ||
|
|
||
| func (c *costEstimator) evict() { | ||
| minCost := math.MaxInt16 | ||
| minCostReq := "" | ||
| i := 0 | ||
| for req, cost := range c.counter { | ||
| if cost < minCost { | ||
| minCost = cost | ||
| minCostReq = req | ||
| } | ||
| i++ | ||
| if i == lfuSample { | ||
| break | ||
| } | ||
| } | ||
| delete(c.counter, minCostReq) | ||
| return | ||
| } | ||
|
|
||
| func (c *costEstimator) clear() { | ||
| c.lock.Lock() | ||
| defer c.lock.Unlock() | ||
| c.counter = make(map[string]int) | ||
| } | ||
|
|
||
| // can be used to optimize to reduce counter periodically like tiny lfu | ||
| func (c *costEstimator) reset() { | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters