fixes #252 Add logging to ease debugging connection reattempts

core.go

@@ -65,6 +65,9 @@ type socket struct {
 
 	// Port hook -- called when a port is added or removed
 	porthook PortHook
+
+	// Debugger -- buffer to collect connection reattempt messages
+	debugger logger
 }
 
 func (sock *socket) addPipe(tranpipe Pipe, d *dialer, l *listener) *pipe {
@@ -560,6 +563,10 @@ func (sock *socket) SetPortHook(newhook PortHook) PortHook {
 	return oldhook
 }
 
+func (sock *socket) Debug() string {
+	return sock.debugger.String()
+}
+
 type dialer struct {
 	d      PipeDialer
 	sock   *socket
@@ -614,6 +621,7 @@ func (d *dialer) dialer() {
 	for {
 		p, err := d.d.Dial()
 		if err == nil {
+			d.sock.debugger.Logf("connected to %s", d.addr)
 			// reset retry time
 			rtime = d.sock.reconntime
 			d.sock.Lock()
@@ -632,6 +640,7 @@ func (d *dialer) dialer() {
 		}
 
 		// we're redialing here
+		d.sock.debugger.Logf("failed to dial %s, retrying: %v", d.addr, err)
 		select {
 		case <-d.closeq: // dialer closed
 			return

log.go

@@ -0,0 +1,38 @@
+package mangos
+
+import (
+	"bytes"
+	"fmt"
+	"sync"
+)
+
+type logger struct {
+	sync.Mutex
+	buf bytes.Buffer
+}
+
+func (l *logger) Log(a ...interface{}) {
+	l.Lock()
+	defer l.Unlock()
+	l.buf.WriteString(fmt.Sprint(a...))
+	l.buf.WriteByte('\n')
+}
+
+func (l *logger) Logf(format string, a ...interface{}) {
+	l.Lock()
+	defer l.Unlock()
+	l.buf.WriteString(fmt.Sprintf(format, a...))
+	l.buf.WriteByte('\n')
+}
+
+func (l *logger) String() string {
+	l.Lock()
+	defer l.Unlock()
+	return l.buf.String()
+}
+
+func (l *logger) Clear() {
+	l.Lock()
+	defer l.Unlock()
+	l.buf.Reset()
+}

socket.go

@@ -80,4 +80,7 @@ type Socket interface {
 	// added or removed from this socket (connect/disconnect).  The previous
 	// hook is returned (nil if none.)
 	SetPortHook(PortHook) PortHook
+
+	// Debug returns a string containing
+	Debug() string
 }