refactor: no globals

it still isn't very clean; globals are avoided with factories, too many
pieces with no clear role

http.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"container/ring"
+	"net/http"
+	"time"
+
+	"github.com/gorilla/websocket"
+	"gopkg.in/mcuadros/go-syslog.v2/format"
+)
+
+func setupHttp(circbuf *ring.Ring, hub Hub) {
+	http.HandleFunc("/", getHTTPHandler(circbuf))
+	http.HandleFunc("/ws", getWSHandler(hub))
+}
+
+func getHTTPHandler(circbuf *ring.Ring) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		circbuf.Do(func(x interface{}) {
+			if x == nil {
+				return
+			}
+			logmsg := x.(format.LogParts)
+			if logmsg["message"] == nil {
+				return
+			}
+			c := logmsg["message"].(string)
+			w.Write([]byte(c))
+			w.Write([]byte("\n"))
+		})
+	}
+}
+
+func getWSHandler(hub Hub) http.HandlerFunc {
+	var upgrader = websocket.Upgrader{
+		ReadBufferSize:  1024,
+		WriteBufferSize: 1024,
+	}
+	return func(w http.ResponseWriter, r *http.Request) {
+		conn, err := upgrader.Upgrade(w, r, nil)
+		if err != nil {
+			return
+		}
+		client := Client{messages: make(chan format.LogParts)}
+		hub.Register <- client
+
+		// Allow collection of memory referenced by the caller by doing all work in
+		// new goroutines.
+		go func(conn *websocket.Conn, c Client) {
+			defer func() {
+				hub.Unregister <- c
+				conn.Close()
+			}()
+			for {
+				select {
+				case message, ok := <-c.messages:
+					conn.SetWriteDeadline(time.Now().Add(10 * time.Second))
+					if !ok {
+						// The hub closed the channel.
+						conn.WriteMessage(websocket.CloseMessage, []byte{})
+						return
+					}
+
+					w, err := conn.NextWriter(websocket.TextMessage)
+					if err != nil {
+						return
+					}
+					if msg, ok := message["message"]; ok {
+						w.Write([]byte(msg.(string)))
+					}
+
+					if err := w.Close(); err != nil {
+						return
+					}
+					// TODO: ticker/ping
+				}
+			}
+		}(conn, client)
+	}
+}

main.go

@@ -6,89 +6,20 @@ import (
 	"fmt"
 	"net/http"
 	"os"
-	"time"
 
-	"github.com/gorilla/websocket"
 	syslog "gopkg.in/mcuadros/go-syslog.v2"
 	"gopkg.in/mcuadros/go-syslog.v2/format"
 )
 
-var circbuf *ring.Ring
-var hub Hub
-var upgrader = websocket.Upgrader{
-	ReadBufferSize:  1024,
-	WriteBufferSize: 1024,
-}
-
-func init() {
-	hub = NewHub()
-}
-
-func syslogdHandler(channel syslog.LogPartsChannel) {
-	for logParts := range channel {
-		hub.logMessages <- logParts
-		fmt.Println(logParts)
-		circbuf.Value = logParts
-		circbuf = circbuf.Next()
-	}
-}
-
-func httpHandler(w http.ResponseWriter, r *http.Request) {
-	circbuf.Do(func(x interface{}) {
-		if x == nil {
-			return
-		}
-		logmsg := x.(format.LogParts)
-		if logmsg["message"] == nil {
-			return
+func getSyslogdHandler(circbuf *ring.Ring, hub Hub) func(channel syslog.LogPartsChannel) {
+	return func(channel syslog.LogPartsChannel) {
+		for logParts := range channel {
+			hub.logMessages <- logParts
+			fmt.Println(logParts)
+			circbuf.Value = logParts
+			circbuf = circbuf.Next()
 		}
-		c := logmsg["message"].(string)
-		w.Write([]byte(c))
-		w.Write([]byte("\n"))
-	})
-}
-
-func wsHandler(w http.ResponseWriter, r *http.Request) {
-	conn, err := upgrader.Upgrade(w, r, nil)
-	if err != nil {
-		return
 	}
-	httpHandler(w, r)
-	client := Client{messages: make(chan format.LogParts)}
-	hub.Register <- client
-
-	// Allow collection of memory referenced by the caller by doing all work in
-	// new goroutines.
-	go func(conn *websocket.Conn, c Client) {
-		defer func() {
-			hub.Unregister <- c
-			conn.Close()
-		}()
-		for {
-			select {
-			case message, ok := <-c.messages:
-				conn.SetWriteDeadline(time.Now().Add(10 * time.Second))
-				if !ok {
-					// The hub closed the channel.
-					conn.WriteMessage(websocket.CloseMessage, []byte{})
-					return
-				}
-
-				w, err := conn.NextWriter(websocket.TextMessage)
-				if err != nil {
-					return
-				}
-				if msg, ok := message["message"]; ok {
-					w.Write([]byte(msg.(string)))
-				}
-
-				if err := w.Close(); err != nil {
-					return
-				}
-				// TODO: ticker/ping
-			}
-		}
-	}(conn, client)
 }
 
 func main() {
@@ -100,6 +31,8 @@ func main() {
 	queryAddr := flag.String("query-addr", "127.0.0.1:9080", "Address:port where to bind the query service")
 	flag.Parse()
 
+	var hub Hub
+	hub = NewHub()
 	channel := make(chan format.LogParts)
 	handler := syslog.NewChannelHandler(channel)
 
@@ -119,18 +52,16 @@ func main() {
 			os.Exit(1)
 		}
 	}
-	circbuf = ring.New(*bufsize)
+	circbuf := ring.New(*bufsize)
 	if err = server.Boot(); err != nil {
 		fmt.Fprintln(os.Stderr, "argh", err)
 		os.Exit(1)
 	}
 	go hub.Run()
-	go syslogdHandler(channel)
+	go getSyslogdHandler(circbuf, hub)(channel)
 
-	http.HandleFunc("/", httpHandler)
-	http.HandleFunc("/ws", wsHandler)
+	setupHttp(circbuf, hub)
 	fmt.Printf("Binding address `%s` [http]\n", *queryAddr)
 	http.ListenAndServe(*queryAddr, nil)
-
 	server.Wait()
 }