tianxiaoliang commented on code in PR #1309: URL: https://github.com/apache/servicecomb-service-center/pull/1309#discussion_r914783074
########## istio/pkg/controllers/istioconnector/controller.go: ########## @@ -0,0 +1,352 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 istioconnector + +import ( + "context" + "fmt" + "sync" + "time" + + "github.com/apache/servicecomb-service-center/istio/pkg/event" + "github.com/apache/servicecomb-service-center/istio/pkg/utils" + "github.com/go-chassis/cari/discovery" + "istio.io/client-go/pkg/apis/networking/v1alpha3" + "istio.io/client-go/pkg/clientset/versioned" + "istio.io/pkg/log" + v1 "k8s.io/apimachinery/pkg/apis/meta/v1" + "k8s.io/client-go/rest" + "k8s.io/client-go/tools/clientcmd" + k8s "sigs.k8s.io/controller-runtime/pkg/client/config" +) + +// Controller receives service center updates and pushes converted Istio ServiceEntry(s) to k8s api server +type Controller struct { + // Istio istioClient for k8s API + istioClient *versioned.Clientset + // Channel used to send and receive service center change events from the service center controller + event chan []event.ChangeEvent + // Lock for service cache + cacheMutex sync.Mutex + // Cache of converted service entries, mapped to original service center service id + convertedServiceCache map[string]*v1alpha3.ServiceEntry +} + +func NewController(kubeconfigPath string, e chan []event.ChangeEvent) (*Controller, error) { + controller := &Controller{ + event: e, + convertedServiceCache: make(map[string]*v1alpha3.ServiceEntry), + } + + // get kubernetes config info, used for creating k8s client + client, err := newKubeClient(kubeconfigPath) + if err != nil { + log.Errorf("Failed to create istio client: %v\n", err) + return nil, err + } + controller.istioClient = client + return controller, nil +} + +// Return a debounced version of a function `fn` that will not run until `wait` seconds have passed +// after it was last called or until `maxWait` seconds have passed since its first call. +// Once `fn` is executed, the max wait timer is reset. +func debounce(fn func(), wait time.Duration, maxWait time.Duration) func() { + // Main timer, time seconds elapsed since last execution + var timer *time.Timer + // Max wait timer, time seconds elapsed since first call + var maxTimer *time.Timer + return func() { + if maxTimer == nil { + // First debounced event, start max wait timer + // will only run target func if not called again after `maxWait` duration + maxTimer = time.AfterFunc(maxWait, func() { + // Reset all timers when max wait time is reached + log.Debugf("Debounce: maximum wait time reached, running target fn\n") + if timer.Stop() { + // Only run target func if main timer hasn't already + fn() + } + timer = nil + maxTimer = nil + }) + log.Debugf("Debounce: max timer started, will wait max time of %s\n", maxWait) + } + if timer != nil { + // Timer already started; function was called within `wait` duration, debounce this event by resetting timer + timer.Stop() + } + // Start timer, will only run target func if not called again after `wait` duration + timer = time.AfterFunc(wait, func() { + log.Debugf("Debounce: timer completed, running target fn\n") + // Reset all timers and run target func when wait time is reached + fn() + maxTimer.Stop() + maxTimer = nil + timer = nil + }) + log.Debugf("Debounce: timer started, will wait %s\n", wait) + } +} + +// Run until a signal is received, this function won't block +func (c *Controller) Run(stop <-chan struct{}) { + go c.watchServiceCenterUpdate(stop) +} + +func (c *Controller) Stop() { + +} + +// Return a debounced version of the push2istio method that merges the passed events on each call. +func (c *Controller) getIstioPushDebouncer(wait time.Duration, maxWait time.Duration, maxEvents int) func([]event.ChangeEvent) { + var eventQueue []event.ChangeEvent // Queue of events merged from arguments of each call to debounced function + // Make a debounced version of push2istio, with provided wait and maxWait times + debouncedFn := debounce(func() { + log.Debugf("Debounce: push callback fired, pushing events to Istio: %v\n", eventQueue) + // Timeout reached, push events to istio and reset queue + c.push2Istio(eventQueue) + eventQueue = nil + }, wait, maxWait) + return func(newEvents []event.ChangeEvent) { + log.Debugf("Debounce: received and merged %d new events\n", len(newEvents)) + // Merge new events with existing event queue for each received call + eventQueue = append(eventQueue, newEvents...) + + log.Debugf("Debounce: new total number of events in queue is %d\n", len(eventQueue)) Review Comment: starts with lower case please ########## istio/pkg/controllers/istioconnector/controller.go: ########## @@ -0,0 +1,352 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 istioconnector + +import ( + "context" + "fmt" + "sync" + "time" + + "github.com/apache/servicecomb-service-center/istio/pkg/event" + "github.com/apache/servicecomb-service-center/istio/pkg/utils" + "github.com/go-chassis/cari/discovery" + "istio.io/client-go/pkg/apis/networking/v1alpha3" + "istio.io/client-go/pkg/clientset/versioned" + "istio.io/pkg/log" + v1 "k8s.io/apimachinery/pkg/apis/meta/v1" + "k8s.io/client-go/rest" + "k8s.io/client-go/tools/clientcmd" + k8s "sigs.k8s.io/controller-runtime/pkg/client/config" +) + +// Controller receives service center updates and pushes converted Istio ServiceEntry(s) to k8s api server +type Controller struct { + // Istio istioClient for k8s API + istioClient *versioned.Clientset + // Channel used to send and receive service center change events from the service center controller + event chan []event.ChangeEvent + // Lock for service cache + cacheMutex sync.Mutex + // Cache of converted service entries, mapped to original service center service id + convertedServiceCache map[string]*v1alpha3.ServiceEntry +} + +func NewController(kubeconfigPath string, e chan []event.ChangeEvent) (*Controller, error) { + controller := &Controller{ + event: e, + convertedServiceCache: make(map[string]*v1alpha3.ServiceEntry), + } + + // get kubernetes config info, used for creating k8s client + client, err := newKubeClient(kubeconfigPath) + if err != nil { + log.Errorf("Failed to create istio client: %v\n", err) + return nil, err + } + controller.istioClient = client + return controller, nil +} + +// Return a debounced version of a function `fn` that will not run until `wait` seconds have passed +// after it was last called or until `maxWait` seconds have passed since its first call. +// Once `fn` is executed, the max wait timer is reset. +func debounce(fn func(), wait time.Duration, maxWait time.Duration) func() { + // Main timer, time seconds elapsed since last execution + var timer *time.Timer + // Max wait timer, time seconds elapsed since first call + var maxTimer *time.Timer + return func() { + if maxTimer == nil { + // First debounced event, start max wait timer + // will only run target func if not called again after `maxWait` duration + maxTimer = time.AfterFunc(maxWait, func() { + // Reset all timers when max wait time is reached + log.Debugf("Debounce: maximum wait time reached, running target fn\n") + if timer.Stop() { + // Only run target func if main timer hasn't already + fn() + } + timer = nil + maxTimer = nil + }) + log.Debugf("Debounce: max timer started, will wait max time of %s\n", maxWait) + } + if timer != nil { + // Timer already started; function was called within `wait` duration, debounce this event by resetting timer + timer.Stop() + } + // Start timer, will only run target func if not called again after `wait` duration + timer = time.AfterFunc(wait, func() { + log.Debugf("Debounce: timer completed, running target fn\n") + // Reset all timers and run target func when wait time is reached + fn() + maxTimer.Stop() + maxTimer = nil + timer = nil + }) + log.Debugf("Debounce: timer started, will wait %s\n", wait) + } +} + +// Run until a signal is received, this function won't block +func (c *Controller) Run(stop <-chan struct{}) { + go c.watchServiceCenterUpdate(stop) +} + +func (c *Controller) Stop() { + Review Comment: why not implement -- This is an automated message from the Apache Git Service. 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