Part 9.

final/wg.go

@@ -145,6 +145,7 @@ func readInput() {
 	if err := s.Err(); err != nil {
 		log.Fatal(err)
 	}
+	os.Exit(0)
 }
 
 func dial(addr string) {

part9/main.go

@@ -7,7 +7,7 @@
 // When it sees a peer with an address it hasn't seen before, it makes a
 // connection to that peer.
 // It adds an ID field containing a random string to each outgoing message.
-// When it recevies a message with an ID it hasn't seen before, it broadcasts
+// When it receives a message with an ID it hasn't seen before, it broadcasts
 // that message to all connected peers.
 //
 package main
@@ -22,16 +22,18 @@ import (
 	"os"
 	"sync"
 
-	"github.com/campoy/whispering-gophers/util"
+	"code.osinet.fr/fgm/whispering_gophers/util"
 )
 
 var (
-	peerAddr = flag.String("peer", "", "peer host:port")
-	self     string
+	listenAddr = flag.String("listen", "", "peer host:port")
+	peerAddr   = flag.String("peer", "", "peer host:port")
+	self       string
 )
 
 type Message struct {
-	// TODO: add ID field
+	// Add ID field
+	ID   string
 	Addr string
 	Body string
 }
@@ -39,7 +41,14 @@ type Message struct {
 func main() {
 	flag.Parse()
 
-	l, err := util.Listen()
+	var l net.Listener
+	var err error
+	// Create a new listener using util.Listen and put it in a variable named l.
+	if *listenAddr == "" {
+		l, err = util.ListenOnFirstUsableInterface()
+	} else {
+		l, err = net.Listen("tcp4", *listenAddr)
+	}
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -117,7 +126,10 @@ func serve(c net.Conn) {
 			return
 		}
 
-		// TODO: If this message has seen before, ignore it.
+		// If this message has seen before, ignore it.
+		if Seen(m.ID) {
+			continue
+		}
 
 		fmt.Printf("%#v\n", m)
 		broadcast(m)
@@ -129,16 +141,18 @@ func readInput() {
 	s := bufio.NewScanner(os.Stdin)
 	for s.Scan() {
 		m := Message{
-			// TODO: use util.RandomID to populate the ID field.
+			// Use util.RandomID to populate the ID field.
 			Addr: self,
 			Body: s.Text(),
+			ID: util.RandomID(),
 		}
-		// TODO: Mark the message ID as seen.
+		Seen(m.ID)
 		broadcast(m)
 	}
 	if err := s.Err(); err != nil {
 		log.Fatal(err)
 	}
+	os.Exit(0)
 }
 
 func dial(addr string) {
@@ -169,12 +183,21 @@ func dial(addr string) {
 	}
 }
 
-// TODO: Create a new map of seen message IDs and a mutex to protect it.
+// Create a new map of seen message IDs and a mutex to protect it.
+var seenIDs = struct {
+	m map[string]bool
+	sync.Mutex
+}{m: make(map[string]bool)}
 
 // Seen returns true if the specified id has been seen before.
 // If not, it returns false and marks the given id as "seen".
 func Seen(id string) bool {
-	// TODO: Get a write lock on the seen message IDs map and unlock it at before returning.
-	// TODO: Check if the id has been seen before and return that later.
-	// TODO: Mark the ID as seen in the map.
+	// Get a write lock on the seen message IDs map and unlock it at before returning.
+	seenIDs.Lock()
+	defer seenIDs.Unlock()
+	// Check if the id has been seen before and return that later.
+	ok := seenIDs.m[id]
+	// Mark the ID as seen in the map.
+	seenIDs.m[id] = true
+	return ok
 }