83 lines
2.8 KiB
Go
83 lines
2.8 KiB
Go
/*
|
|
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,
|
|
}
|
|
}
|