l-12

vendor/k8s.io/client-go/tools/cache/reflector.go

@@ -45,6 +45,7 @@ import (
 
 const defaultExpectedTypeName = "<unspecified>"
 
+// Reflector 的数据结构
 // Reflector watches a specified resource and causes all changes to be reflected in the given store.
 type Reflector struct {
 	// name identifies this reflector. By default it will be a file:line if possible.
@@ -54,19 +55,20 @@ type Reflector struct {
 	// will be the stringification of expectedGVK if provided, and the
 	// stringification of expectedType otherwise. It is for display
 	// only, and should not be used for parsing or comparison.
-	expectedTypeName string
+	expectedTypeName string // 期望的，关注的，订阅的类型名
 	// An example object of the type we expect to place in the store.
 	// Only the type needs to be right, except that when that is
 	// `unstructured.Unstructured` the object's `"apiVersion"` and
 	// `"kind"` must also be right.
-	expectedType reflect.Type
+	expectedType reflect.Type // 满足 “类型” 的类型
 	// The GVK of the object we expect to place in the store if unstructured.
-	expectedGVK *schema.GroupVersionKind
+	expectedGVK *schema.GroupVersionKind // 用GVK来标注“类型”
 	// The destination to sync up with the watch source
-	store Store
+	store Store // 存储list&watch结果的地方
 	// listerWatcher is used to perform lists and watches.
-	listerWatcher ListerWatcher
+	listerWatcher ListerWatcher // 提供 list & Watch 方法的对象
 
+	// List & Watch 行为的一些参数
 	// backoff manages backoff of ListWatch
 	backoffManager wait.BackoffManager
 	// initConnBackoffManager manages backoff the initial connection with the Watch call of ListAndWatch.
@@ -74,14 +76,17 @@ type Reflector struct {
 	// MaxInternalErrorRetryDuration defines how long we should retry internal errors returned by watch.
 	MaxInternalErrorRetryDuration time.Duration
 
-	resyncPeriod time.Duration
+	// 设置 Resync 操作的参数
+	resyncPeriod time.Duration // 自动resync的间隔时间
 	// ShouldResync is invoked periodically and whenever it returns `true` the Store's Resync operation is invoked
-	ShouldResync func() bool
+	ShouldResync func() bool // 主动执行resync，这个方法被调用后，返回“true” resync 就会被执行
 	// clock allows tests to manipulate time
-	clock clock.Clock
+	clock clock.Clock // 测试来使用的
 	// paginatedResult defines whether pagination should be forced for list calls.
 	// It is set based on the result of the initial list call.
-	paginatedResult bool
+	paginatedResult bool // 是否使用分页
+
+	// 乐观锁的实现
 	// lastSyncResourceVersion is the resource version token last
 	// observed when doing a sync with the underlying store
 	// it is thread safe, but not synchronized with the underlying store
@@ -98,7 +103,7 @@ type Reflector struct {
 	// NOTE: It should be used carefully as paginated lists are always served directly from
 	// etcd, which is significantly less efficient and may lead to serious performance and
 	// scalability problems.
-	WatchListPageSize int64
+	WatchListPageSize int64 // 分页的页大小
 	// Called whenever the ListAndWatch drops the connection with an error.
 	watchErrorHandler WatchErrorHandler
 }
@@ -147,6 +152,8 @@ var (
 	minWatchTimeout = 5 * time.Minute
 )
 
+// 创建 Reflector 的方法
+
 // NewNamespaceKeyedIndexerAndReflector creates an Indexer and a Reflector
 // The indexer is configured to key on namespace
 func NewNamespaceKeyedIndexerAndReflector(lw ListerWatcher, expectedType interface{}, resyncPeriod time.Duration) (indexer Indexer, reflector *Reflector) {
@@ -169,13 +176,21 @@ func NewReflector(lw ListerWatcher, expectedType interface{}, store Store, resyn
 	return NewNamedReflector(naming.GetNameFromCallsite(internalPackages...), lw, expectedType, store, resyncPeriod)
 }
 
+
+// 创建 Reflector 的最终地方
 // NewNamedReflector same as NewReflector, but with a specified name for logging
 func NewNamedReflector(name string, lw ListerWatcher, expectedType interface{}, store Store, resyncPeriod time.Duration) *Reflector {
+	// 创建始终，可以让测试的时候调整
 	realClock := &clock.RealClock{}
+
+	// 创建 Reflector 数据
 	r := &Reflector{
 		name:          name,
-		listerWatcher: lw,
+		// 这两个对象是 reflector 与外部交互的重要对象
-		store:         store,
+		listerWatcher: lw, // 外部传进来的 提供 list & watch 方法的对象
+		store:         store, // 外部传进来的 提供存储的对象
+
+		// 同步时，重试等操作测方法及参数
 		// We used to make the call every 1sec (1 QPS), the goal here is to achieve ~98% traffic reduction when
 		// API server is not healthy. With these parameters, backoff will stop at [30,60) sec interval which is
 		// 0.22 QPS. If we don't backoff for 2min, assume API server is healthy and we reset the backoff.
@@ -185,21 +200,29 @@ func NewNamedReflector(name string, lw ListerWatcher, expectedType interface{},
 		clock:                  realClock,
 		watchErrorHandler:      WatchErrorHandler(DefaultWatchErrorHandler),
 	}
+
+	// 设置关注类型的方法
 	r.setExpectedType(expectedType)
 	return r
 }
 
+// 设置关注类型的方法实现。这里所说的类型都为 GVK 名字
 func (r *Reflector) setExpectedType(expectedType interface{}) {
+	// 获取类型名称
 	r.expectedType = reflect.TypeOf(expectedType)
 	if r.expectedType == nil {
+		// 如果是空类型或者其他原因设置失败，导致该值为空，则使用默认的类型名
 		r.expectedTypeName = defaultExpectedTypeName
 		return
 	}
 
+	// 将类型转换为容易识别的字符串。
 	r.expectedTypeName = r.expectedType.String()
 
+	// 处理动态类型的相关操作
 	if obj, ok := expectedType.(*unstructured.Unstructured); ok {
 		// Use gvk to check that watch event objects are of the desired type.
+		// 动态的获取类型
 		gvk := obj.GroupVersionKind()
 		if gvk.Empty() {
 			klog.V(4).Infof("Reflector from %s configured with expectedType of *unstructured.Unstructured with empty GroupVersionKind.", r.name)