|
| 1 | +// The code in this file is copied from k8s.io/client-go/tools/cache/controller.go. |
| 2 | +// It contains minor modifications to the original code. |
| 3 | + |
| 4 | +/* |
| 5 | +Copyright 2014 The Kubernetes Authors. |
| 6 | +
|
| 7 | +Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | +you may not use this file except in compliance with the License. |
| 9 | +You may obtain a copy of the License at |
| 10 | +
|
| 11 | + http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | +
|
| 13 | +Unless required by applicable law or agreed to in writing, software |
| 14 | +distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | +See the License for the specific language governing permissions and |
| 17 | +limitations under the License. |
| 18 | +*/ |
| 19 | + |
| 20 | +package cache |
| 21 | + |
| 22 | +import ( |
| 23 | + "context" |
| 24 | + "sync" |
| 25 | + "time" |
| 26 | + |
| 27 | + utilruntime "k8s.io/apimachinery/pkg/util/runtime" |
| 28 | + "k8s.io/apimachinery/pkg/util/wait" |
| 29 | + "k8s.io/client-go/tools/cache" |
| 30 | + "k8s.io/utils/clock" |
| 31 | +) |
| 32 | + |
| 33 | +var _ cache.Controller = &Controller{} |
| 34 | + |
| 35 | +// Controller is a controller that uses a reflector to watch a resource and update a queue. |
| 36 | +// It is copied over from k8s.io/client-go/tools/cache/controller.go. |
| 37 | +type Controller struct { |
| 38 | + config cache.Config |
| 39 | + clock clock.Clock |
| 40 | + reflector *Reflector |
| 41 | + reflectorMutex sync.RWMutex |
| 42 | + // UseWatchList if turned on instructs the reflector to open a stream to bring data from the API server. |
| 43 | + // Defaults to false. |
| 44 | + UseWatchList bool |
| 45 | + // WatchListPageSize is the requested chunk size for paginated LIST operations. |
| 46 | + // An empty value (0) will use client-go's default pagination behavior. |
| 47 | + WatchListPageSize int64 |
| 48 | +} |
| 49 | + |
| 50 | +// NewController makes a new Controller from the given Config. |
| 51 | +func NewController(c *cache.Config) *Controller { |
| 52 | + ctlr := &Controller{ |
| 53 | + config: *c, |
| 54 | + clock: &clock.RealClock{}, |
| 55 | + } |
| 56 | + return ctlr |
| 57 | +} |
| 58 | + |
| 59 | +// Run implements [Controller.Run]. |
| 60 | +func (c *Controller) Run(stopCh <-chan struct{}) { |
| 61 | + c.RunWithContext(wait.ContextForChannel(stopCh)) |
| 62 | +} |
| 63 | + |
| 64 | +// RunWithContext implements [Controller.RunWithContext]. |
| 65 | +func (c *Controller) RunWithContext(ctx context.Context) { |
| 66 | + defer utilruntime.HandleCrashWithContext(ctx) |
| 67 | + |
| 68 | + go func() { |
| 69 | + <-ctx.Done() |
| 70 | + c.config.Queue.Close() |
| 71 | + }() |
| 72 | + |
| 73 | + var useWatchList *bool |
| 74 | + if c.UseWatchList { |
| 75 | + val := true |
| 76 | + useWatchList = &val |
| 77 | + } |
| 78 | + |
| 79 | + r := NewReflectorWithOptions( |
| 80 | + cache.ToListerWatcherWithContext(c.config.ListerWatcher), |
| 81 | + c.config.ObjectType, |
| 82 | + c.config.Queue, |
| 83 | + ReflectorOptions{ |
| 84 | + ResyncPeriod: c.config.FullResyncPeriod, |
| 85 | + MinWatchTimeout: c.config.MinWatchTimeout, |
| 86 | + TypeDescription: c.config.ObjectDescription, |
| 87 | + Clock: c.clock, |
| 88 | + UseWatchList: useWatchList, |
| 89 | + }, |
| 90 | + ) |
| 91 | + r.ShouldResync = c.config.ShouldResync |
| 92 | + r.WatchListPageSize = c.WatchListPageSize |
| 93 | + |
| 94 | + c.reflectorMutex.Lock() |
| 95 | + c.reflector = r |
| 96 | + c.reflectorMutex.Unlock() |
| 97 | + |
| 98 | + var wg wait.Group |
| 99 | + |
| 100 | + wg.StartWithContext(ctx, r.RunWithContext) |
| 101 | + |
| 102 | + wait.UntilWithContext(ctx, c.processLoop, time.Second) |
| 103 | + wg.Wait() |
| 104 | +} |
| 105 | + |
| 106 | +// HasSynced returns true once this cache has completed an initial resource listing. |
| 107 | +func (c *Controller) HasSynced() bool { |
| 108 | + return c.config.Queue.HasSynced() |
| 109 | +} |
| 110 | + |
| 111 | +// LastSyncResourceVersion returns the last sync resource version of the cache. |
| 112 | +func (c *Controller) LastSyncResourceVersion() string { |
| 113 | + c.reflectorMutex.RLock() |
| 114 | + defer c.reflectorMutex.RUnlock() |
| 115 | + if c.reflector == nil { |
| 116 | + return "" |
| 117 | + } |
| 118 | + return c.reflector.LastSyncResourceVersion() |
| 119 | +} |
| 120 | + |
| 121 | +// processLoop drains the work queue. |
| 122 | +func (c *Controller) processLoop(ctx context.Context) { |
| 123 | + for { |
| 124 | + select { |
| 125 | + case <-ctx.Done(): |
| 126 | + // If the context is canceled, we have to exit the loop, even without draining the queue. |
| 127 | + // So we close the queue and return. |
| 128 | + c.config.Queue.Close() |
| 129 | + return |
| 130 | + default: |
| 131 | + _, err := c.config.Queue.Pop(cache.PopProcessFunc(c.config.Process)) |
| 132 | + if err != nil { |
| 133 | + if err == cache.ErrFIFOClosed { |
| 134 | + return |
| 135 | + } |
| 136 | + } |
| 137 | + } |
| 138 | + } |
| 139 | +} |
0 commit comments