| /* |
| Copyright 2016 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 controller |
| |
| import ( |
| "hash/fnv" |
| "sync" |
| |
| "github.com/golang/groupcache/lru" |
| metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" |
| hashutil "k8s.io/kubernetes/pkg/util/hash" |
| ) |
| |
| type objectWithMeta interface { |
| metav1.Object |
| } |
| |
| // keyFunc returns the key of an object, which is used to look up in the cache for it's matching object. |
| // Since we match objects by namespace and Labels/Selector, so if two objects have the same namespace and labels, |
| // they will have the same key. |
| func keyFunc(obj objectWithMeta) uint64 { |
| hash := fnv.New32a() |
| hashutil.DeepHashObject(hash, &equivalenceLabelObj{ |
| namespace: obj.GetNamespace(), |
| labels: obj.GetLabels(), |
| }) |
| return uint64(hash.Sum32()) |
| } |
| |
| type equivalenceLabelObj struct { |
| namespace string |
| labels map[string]string |
| } |
| |
| // MatchingCache save label and selector matching relationship |
| type MatchingCache struct { |
| mutex sync.RWMutex |
| cache *lru.Cache |
| } |
| |
| // NewMatchingCache return a NewMatchingCache, which save label and selector matching relationship. |
| func NewMatchingCache(maxCacheEntries int) *MatchingCache { |
| return &MatchingCache{ |
| cache: lru.New(maxCacheEntries), |
| } |
| } |
| |
| // Add will add matching information to the cache. |
| func (c *MatchingCache) Add(labelObj objectWithMeta, selectorObj objectWithMeta) { |
| key := keyFunc(labelObj) |
| c.mutex.Lock() |
| defer c.mutex.Unlock() |
| c.cache.Add(key, selectorObj) |
| } |
| |
| // GetMatchingObject lookup the matching object for a given object. |
| // Note: the cache information may be invalid since the controller may be deleted or updated, |
| // we need check in the external request to ensure the cache data is not dirty. |
| func (c *MatchingCache) GetMatchingObject(labelObj objectWithMeta) (controller interface{}, exists bool) { |
| key := keyFunc(labelObj) |
| // NOTE: we use Lock() instead of RLock() here because lru's Get() method also modifies state( |
| // it need update the least recently usage information). So we can not call it concurrently. |
| c.mutex.Lock() |
| defer c.mutex.Unlock() |
| return c.cache.Get(key) |
| } |
| |
| // Update update the cached matching information. |
| func (c *MatchingCache) Update(labelObj objectWithMeta, selectorObj objectWithMeta) { |
| c.Add(labelObj, selectorObj) |
| } |
| |
| // InvalidateAll invalidate the whole cache. |
| func (c *MatchingCache) InvalidateAll() { |
| c.mutex.Lock() |
| defer c.mutex.Unlock() |
| c.cache = lru.New(c.cache.MaxEntries) |
| } |