fix high cpu usage with new ticker in each for loop (#64)

Author: zzzming

config/pulsar_beam.yml

@@ -1,7 +1,7 @@
 ---
 PORT: 8085
 CLUSTER: localhost
-PbDbType: mongo
+PbDbType: inmemory
 PulsarPublicKey: ./unit-test/example_public_key.pub
 PulsarPrivateKey: ./unit-test/example_private_key
 PbDbInterval: 10s

src/broker/webhook.go

@@ -71,9 +71,10 @@ func Init() {
 
 	go func() {
 		run()
+		ticker := time.NewTicker(duration)
 		for {
 			select {
-			case <-time.Tick(duration):
+			case <-ticker.C:
 				run()
 			}
 		}
@@ -195,11 +196,13 @@ func ConsumeLoop(url, token, topic, subscriptionKey string, whCfg model.WebhookC
 		if err != nil {
 			log.Infof("error from consumer loop receive: %v\n", err)
 			retry++
+			ticker := time.NewTicker(time.Duration(2*retry) * time.Second)
+			defer ticker.Stop()
 			select {
 			case <-terminate:
 				log.Infof("subscription %s received signal to exit consumer loop", subscriptionKey)
 				return nil
-			case <-time.Tick(time.Duration(2*retry) * time.Second):
+			case <-ticker.C:
 				//reconnect after error
 				c, err = pulsardriver.GetPulsarConsumer(url, token, topic, whCfg.Subscription, whCfg.InitialPosition, whCfg.SubscriptionType, subscriptionKey)
 				if err != nil {

src/util/cert-loader.go

@@ -42,9 +42,10 @@ func watchFile(filePath string, updated chan *updatedChann) error {
 		return err
 	}
 
+	ticker := time.NewTicker(1 * time.Second)
 	for {
 		select {
-		case <-time.Tick(1 * time.Second):
+		case <-ticker.C:
 			stat, err := os.Stat(filePath)
 			if err == nil {
 				if stat.Size() != initialStat.Size() || stat.ModTime() != initialStat.ModTime() {

src/util/ttlcache.go

@@ -57,9 +57,10 @@ func (c *Cache) Get(key string) (interface{}, bool) {
 
 // eventLoop name is a disguise. I should convert the lock/unlock to an event loop
 func (c *Cache) eventLoop() {
+	ticker := time.NewTicker(c.opt.CleanInterval)
 	for {
 		select {
-		case <-time.Tick(c.opt.CleanInterval):
+		case <-ticker.C:
 			// RLock is faster than Lock, performant improve to get a slice of keys first
 			c.mutex.RLock()
 			keys := make([]string, 0, len(c.items))