2 Copyright 2015 The Kubernetes Authors.
4 Licensed under the Apache License, Version 2.0 (the "License");
5 you may not use this file except in compliance with the License.
6 You may obtain a copy of the License at
8 http://www.apache.org/licenses/LICENSE-2.0
10 Unless required by applicable law or agreed to in writing, software
11 distributed under the License is distributed on an "AS IS" BASIS,
12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 See the License for the specific language governing permissions and
14 limitations under the License.
19 // UndeltaStore listens to incremental updates and sends complete state on every change.
20 // It implements the Store interface so that it can receive a stream of mirrored objects
21 // from Reflector. Whenever it receives any complete (Store.Replace) or incremental change
22 // (Store.Add, Store.Update, Store.Delete), it sends the complete state by calling PushFunc.
23 // It is thread-safe. It guarantees that every change (Add, Update, Replace, Delete) results
24 // in one call to PushFunc, but sometimes PushFunc may be called twice with the same values.
25 // PushFunc should be thread safe.
26 type UndeltaStore struct {
28 PushFunc func([]interface{})
31 // Assert that it implements the Store interface.
32 var _ Store = &UndeltaStore{}
34 // Note about thread safety. The Store implementation (cache.cache) uses a lock for all methods.
35 // In the functions below, the lock gets released and reacquired betweend the {Add,Delete,etc}
36 // and the List. So, the following can happen, resulting in two identical calls to PushFunc.
37 // time thread 1 thread 2
38 // 0 UndeltaStore.Add(a)
39 // 1 UndeltaStore.Add(b)
42 // 4 Store.List() -> [a,b]
43 // 5 Store.List() -> [a,b]
45 func (u *UndeltaStore) Add(obj interface{}) error {
46 if err := u.Store.Add(obj); err != nil {
49 u.PushFunc(u.Store.List())
53 func (u *UndeltaStore) Update(obj interface{}) error {
54 if err := u.Store.Update(obj); err != nil {
57 u.PushFunc(u.Store.List())
61 func (u *UndeltaStore) Delete(obj interface{}) error {
62 if err := u.Store.Delete(obj); err != nil {
65 u.PushFunc(u.Store.List())
69 func (u *UndeltaStore) Replace(list []interface{}, resourceVersion string) error {
70 if err := u.Store.Replace(list, resourceVersion); err != nil {
73 u.PushFunc(u.Store.List())
77 // NewUndeltaStore returns an UndeltaStore implemented with a Store.
78 func NewUndeltaStore(pushFunc func([]interface{}), keyFunc KeyFunc) *UndeltaStore {
80 Store: NewStore(keyFunc),