diff options
Diffstat (limited to 'kube2msb/src/vendor/k8s.io/kubernetes/pkg/client/cache/expiration_cache.go')
| -rw-r--r-- | kube2msb/src/vendor/k8s.io/kubernetes/pkg/client/cache/expiration_cache.go | 208 |
1 files changed, 0 insertions, 208 deletions
diff --git a/kube2msb/src/vendor/k8s.io/kubernetes/pkg/client/cache/expiration_cache.go b/kube2msb/src/vendor/k8s.io/kubernetes/pkg/client/cache/expiration_cache.go deleted file mode 100644 index 8c5c470..0000000 --- a/kube2msb/src/vendor/k8s.io/kubernetes/pkg/client/cache/expiration_cache.go +++ /dev/null @@ -1,208 +0,0 @@ -/* -Copyright 2014 The Kubernetes Authors. - -Licensed under the Apache License, Version 2.0 (the "License"); -you may not use this file except in compliance with the License. -You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - -Unless required by applicable law or agreed to in writing, software -distributed under the License is distributed on an "AS IS" BASIS, -WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -See the License for the specific language governing permissions and -limitations under the License. -*/ - -package cache - -import ( - "sync" - "time" - - "github.com/golang/glog" - "k8s.io/kubernetes/pkg/util" -) - -// ExpirationCache implements the store interface -// 1. All entries are automatically time stamped on insert -// a. The key is computed based off the original item/keyFunc -// b. The value inserted under that key is the timestamped item -// 2. Expiration happens lazily on read based on the expiration policy -// a. No item can be inserted into the store while we're expiring -// *any* item in the cache. -// 3. Time-stamps are stripped off unexpired entries before return -// Note that the ExpirationCache is inherently slower than a normal -// threadSafeStore because it takes a write lock every time it checks if -// an item has expired. -type ExpirationCache struct { - cacheStorage ThreadSafeStore - keyFunc KeyFunc - clock util.Clock - expirationPolicy ExpirationPolicy - // expirationLock is a write lock used to guarantee that we don't clobber - // newly inserted objects because of a stale expiration timestamp comparison - expirationLock sync.Mutex -} - -// ExpirationPolicy dictates when an object expires. Currently only abstracted out -// so unittests don't rely on the system clock. -type ExpirationPolicy interface { - IsExpired(obj *timestampedEntry) bool -} - -// TTLPolicy implements a ttl based ExpirationPolicy. -type TTLPolicy struct { - // >0: Expire entries with an age > ttl - // <=0: Don't expire any entry - Ttl time.Duration - - // Clock used to calculate ttl expiration - Clock util.Clock -} - -// IsExpired returns true if the given object is older than the ttl, or it can't -// determine its age. -func (p *TTLPolicy) IsExpired(obj *timestampedEntry) bool { - return p.Ttl > 0 && p.Clock.Since(obj.timestamp) > p.Ttl -} - -// timestampedEntry is the only type allowed in a ExpirationCache. -type timestampedEntry struct { - obj interface{} - timestamp time.Time -} - -// getTimestampedEntry returnes the timestampedEntry stored under the given key. -func (c *ExpirationCache) getTimestampedEntry(key string) (*timestampedEntry, bool) { - item, _ := c.cacheStorage.Get(key) - if tsEntry, ok := item.(*timestampedEntry); ok { - return tsEntry, true - } - return nil, false -} - -// getOrExpire retrieves the object from the timestampedEntry if and only if it hasn't -// already expired. It holds a write lock across deletion. -func (c *ExpirationCache) getOrExpire(key string) (interface{}, bool) { - // Prevent all inserts from the time we deem an item as "expired" to when we - // delete it, so an un-expired item doesn't sneak in under the same key, just - // before the Delete. - c.expirationLock.Lock() - defer c.expirationLock.Unlock() - timestampedItem, exists := c.getTimestampedEntry(key) - if !exists { - return nil, false - } - if c.expirationPolicy.IsExpired(timestampedItem) { - glog.V(4).Infof("Entry %v: %+v has expired", key, timestampedItem.obj) - c.cacheStorage.Delete(key) - return nil, false - } - return timestampedItem.obj, true -} - -// GetByKey returns the item stored under the key, or sets exists=false. -func (c *ExpirationCache) GetByKey(key string) (interface{}, bool, error) { - obj, exists := c.getOrExpire(key) - return obj, exists, nil -} - -// Get returns unexpired items. It purges the cache of expired items in the -// process. -func (c *ExpirationCache) Get(obj interface{}) (interface{}, bool, error) { - key, err := c.keyFunc(obj) - if err != nil { - return nil, false, KeyError{obj, err} - } - obj, exists := c.getOrExpire(key) - return obj, exists, nil -} - -// List retrieves a list of unexpired items. It purges the cache of expired -// items in the process. -func (c *ExpirationCache) List() []interface{} { - items := c.cacheStorage.List() - - list := make([]interface{}, 0, len(items)) - for _, item := range items { - obj := item.(*timestampedEntry).obj - if key, err := c.keyFunc(obj); err != nil { - list = append(list, obj) - } else if obj, exists := c.getOrExpire(key); exists { - list = append(list, obj) - } - } - return list -} - -// ListKeys returns a list of all keys in the expiration cache. -func (c *ExpirationCache) ListKeys() []string { - return c.cacheStorage.ListKeys() -} - -// Add timestamps an item and inserts it into the cache, overwriting entries -// that might exist under the same key. -func (c *ExpirationCache) Add(obj interface{}) error { - c.expirationLock.Lock() - defer c.expirationLock.Unlock() - - key, err := c.keyFunc(obj) - if err != nil { - return KeyError{obj, err} - } - c.cacheStorage.Add(key, ×tampedEntry{obj, c.clock.Now()}) - return nil -} - -// Update has not been implemented yet for lack of a use case, so this method -// simply calls `Add`. This effectively refreshes the timestamp. -func (c *ExpirationCache) Update(obj interface{}) error { - return c.Add(obj) -} - -// Delete removes an item from the cache. -func (c *ExpirationCache) Delete(obj interface{}) error { - c.expirationLock.Lock() - defer c.expirationLock.Unlock() - key, err := c.keyFunc(obj) - if err != nil { - return KeyError{obj, err} - } - c.cacheStorage.Delete(key) - return nil -} - -// Replace will convert all items in the given list to TimestampedEntries -// before attempting the replace operation. The replace operation will -// delete the contents of the ExpirationCache `c`. -func (c *ExpirationCache) Replace(list []interface{}, resourceVersion string) error { - c.expirationLock.Lock() - defer c.expirationLock.Unlock() - items := map[string]interface{}{} - ts := c.clock.Now() - for _, item := range list { - key, err := c.keyFunc(item) - if err != nil { - return KeyError{item, err} - } - items[key] = ×tampedEntry{item, ts} - } - c.cacheStorage.Replace(items, resourceVersion) - return nil -} - -// Resync will touch all objects to put them into the processing queue -func (c *ExpirationCache) Resync() error { - return c.cacheStorage.Resync() -} - -// NewTTLStore creates and returns a ExpirationCache with a TTLPolicy -func NewTTLStore(keyFunc KeyFunc, ttl time.Duration) Store { - return &ExpirationCache{ - cacheStorage: NewThreadSafeStore(Indexers{}, Indices{}), - keyFunc: keyFunc, - clock: util.RealClock{}, - expirationPolicy: &TTLPolicy{ttl, util.RealClock{}}, - } -} |