| /* |
| Copyright 2015 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 |
| |
| // UndeltaStore listens to incremental updates and sends complete state on every change. |
| // It implements the Store interface so that it can receive a stream of mirrored objects |
| // from Reflector. Whenever it receives any complete (Store.Replace) or incremental change |
| // (Store.Add, Store.Update, Store.Delete), it sends the complete state by calling PushFunc. |
| // It is thread-safe. It guarantees that every change (Add, Update, Replace, Delete) results |
| // in one call to PushFunc, but sometimes PushFunc may be called twice with the same values. |
| // PushFunc should be thread safe. |
| type UndeltaStore struct { |
| Store |
| PushFunc func([]interface{}) |
| } |
| |
| // Assert that it implements the Store interface. |
| var _ Store = &UndeltaStore{} |
| |
| // Note about thread safety. The Store implementation (cache.cache) uses a lock for all methods. |
| // In the functions below, the lock gets released and reacquired betweend the {Add,Delete,etc} |
| // and the List. So, the following can happen, resulting in two identical calls to PushFunc. |
| // time thread 1 thread 2 |
| // 0 UndeltaStore.Add(a) |
| // 1 UndeltaStore.Add(b) |
| // 2 Store.Add(a) |
| // 3 Store.Add(b) |
| // 4 Store.List() -> [a,b] |
| // 5 Store.List() -> [a,b] |
| |
| func (u *UndeltaStore) Add(obj interface{}) error { |
| if err := u.Store.Add(obj); err != nil { |
| return err |
| } |
| u.PushFunc(u.Store.List()) |
| return nil |
| } |
| |
| func (u *UndeltaStore) Update(obj interface{}) error { |
| if err := u.Store.Update(obj); err != nil { |
| return err |
| } |
| u.PushFunc(u.Store.List()) |
| return nil |
| } |
| |
| func (u *UndeltaStore) Delete(obj interface{}) error { |
| if err := u.Store.Delete(obj); err != nil { |
| return err |
| } |
| u.PushFunc(u.Store.List()) |
| return nil |
| } |
| |
| func (u *UndeltaStore) Replace(list []interface{}, resourceVersion string) error { |
| if err := u.Store.Replace(list, resourceVersion); err != nil { |
| return err |
| } |
| u.PushFunc(u.Store.List()) |
| return nil |
| } |
| |
| // NewUndeltaStore returns an UndeltaStore implemented with a Store. |
| func NewUndeltaStore(pushFunc func([]interface{}), keyFunc KeyFunc) *UndeltaStore { |
| return &UndeltaStore{ |
| Store: NewStore(keyFunc), |
| PushFunc: pushFunc, |
| } |
| } |