From 87c3790fa8f5cb7b6bfbfe05321587aa3057b2fb Mon Sep 17 00:00:00 2001
From: Jakob Borg <jakob@nym.se>
Date: Fri, 25 Jul 2014 14:50:14 +0200
Subject: [PATCH] Debug events module

---
 cmd/syncthing/main.go |  1 +
 events/debug.go       | 17 +++++++++++++++++
 events/events.go      | 17 +++++++++++++++++
 events/events_test.go |  4 ++++
 4 files changed, 39 insertions(+)
 create mode 100644 events/debug.go

diff --git a/cmd/syncthing/main.go b/cmd/syncthing/main.go
index 016b7b8b1..b66b1f6d8 100644
--- a/cmd/syncthing/main.go
+++ b/cmd/syncthing/main.go
@@ -107,6 +107,7 @@ The following enviroment variables are interpreted by syncthing:
                facility strings:
                - "beacon"   (the beacon package)
                - "discover" (the discover package)
+               - "events"   (the events package)
                - "files"    (the files package)
                - "net"      (the main package; connections & network messages)
                - "model"    (the model package)
diff --git a/events/debug.go b/events/debug.go
new file mode 100644
index 000000000..64c22b7cc
--- /dev/null
+++ b/events/debug.go
@@ -0,0 +1,17 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package events
+
+import (
+	"os"
+	"strings"
+
+	"github.com/calmh/syncthing/logger"
+)
+
+var (
+	debug = strings.Contains(os.Getenv("STTRACE"), "events") || os.Getenv("STTRACE") == "all"
+	dl    = logger.DefaultLogger
+)
diff --git a/events/events.go b/events/events.go
index 52b95b7b0..d464ed8af 100644
--- a/events/events.go
+++ b/events/events.go
@@ -1,3 +1,7 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
 // Package events provides event subscription and polling functionality.
 package events
 
@@ -93,6 +97,9 @@ func NewLogger() *Logger {
 
 func (l *Logger) Log(t EventType, data interface{}) {
 	l.mutex.Lock()
+	if debug {
+		dl.Debugln("log", l.nextId, t.String(), data)
+	}
 	e := Event{
 		ID:   l.nextId,
 		Time: time.Now(),
@@ -114,6 +121,9 @@ func (l *Logger) Log(t EventType, data interface{}) {
 
 func (l *Logger) Subscribe(mask EventType) *Subscription {
 	l.mutex.Lock()
+	if debug {
+		dl.Debugln("subscribe", mask)
+	}
 	s := &Subscription{
 		mask:   mask,
 		id:     l.nextId,
@@ -127,6 +137,9 @@ func (l *Logger) Subscribe(mask EventType) *Subscription {
 
 func (l *Logger) Unsubscribe(s *Subscription) {
 	l.mutex.Lock()
+	if debug {
+		dl.Debugln("unsubsribe")
+	}
 	delete(l.subs, s.id)
 	close(s.events)
 	l.mutex.Unlock()
@@ -136,6 +149,10 @@ func (s *Subscription) Poll(timeout time.Duration) (Event, error) {
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
 
+	if debug {
+		dl.Debugln("poll", timeout)
+	}
+
 	to := time.After(timeout)
 	select {
 	case e, ok := <-s.events:
diff --git a/events/events_test.go b/events/events_test.go
index ffc4adfe4..4a44284ed 100644
--- a/events/events_test.go
+++ b/events/events_test.go
@@ -1,3 +1,7 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
 package events_test
 
 import (