Challenge loong#1 completed

1-producer-consumer/main.go

@@ -1,6 +1,6 @@
 //////////////////////////////////////////////////////////////////////
 //
-// Given is a producer-consumer szenario, where a producer reads in
+// Given is a producer-consumer scenario, where a producer reads in
 // tweets from a mockstream and a consumer is processing the
 // data. Your task is to change the code so that the producer as well
 // as the consumer can run concurrently
@@ -10,22 +10,27 @@ package main
 
 import (
 	"fmt"
+	"sync"
 	"time"
 )
 
-func producer(stream Stream) (tweets []*Tweet) {
+func producer(wg *sync.WaitGroup, stream Stream, tweets chan *Tweet) {
+	defer wg.Done()
+
 	for {
 		tweet, err := stream.Next()
 		if err == ErrEOF {
-			return tweets
+			return
 		}
 
-		tweets = append(tweets, tweet)
+		tweets <- tweet
 	}
 }
 
-func consumer(tweets []*Tweet) {
-	for _, t := range tweets {
+func consumer(wg *sync.WaitGroup, tweets <-chan *Tweet) {
+	defer wg.Done()
+
+	for t := range tweets {
 		if t.IsTalkingAboutGo() {
 			fmt.Println(t.Username, "\ttweets about golang")
 		} else {
@@ -35,14 +40,29 @@ func consumer(tweets []*Tweet) {
 }
 
 func main() {
+
+	// This also works without making consumer a go func
+	// but I thought I'd practice with wait groups.
+	// Both functions are running concurrently, however,
+	// consumer only finishes after producer does (as it's dependant on it),
+	// making the wait at the end a bit unnecessary.
+	wg := new(sync.WaitGroup)
+
+	// Two go funcs hence the number two here and two "defer wg.Done()"
+	wg.Add(2)
+
 	start := time.Now()
 	stream := GetMockStream()
 
 	// Producer
-	tweets := producer(stream)
+	tweets := make(chan *Tweet)
+	go producer(wg, stream, tweets)
 
 	// Consumer
-	consumer(tweets)
+	go consumer(wg, tweets)
+
+	// wait for the go routines to finish
+	wg.Wait()
 
 	fmt.Printf("Process took %s\n", time.Since(start))
 }