From: Matt Joiner <anacrolix@gmail.com>
Date: Sun, 20 Dec 2020 22:29:20 +0000 (+1100)
Subject: Pass trackerScraper context to announces
X-Git-Tag: v1.20.0~11
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=b67ccab7f2a687ddf75a31bc0206f6c11c58bd39;p=btrtrc.git

Pass trackerScraper context to announces

This will cancel announces for Closed Torrents and let them move more quickly to announcing the stopped event. Spotted by @hwh33.
---

diff --git a/tracker/tracker.go b/tracker/tracker.go
index 65cad803..7f2a5b50 100644
--- a/tracker/tracker.go
+++ b/tracker/tracker.go
@@ -66,6 +66,9 @@ type Announce struct {
 	Context   context.Context
 }
 
+// The code *is* the documentation.
+const DefaultTrackerAnnounceTimeout = 15 * time.Second
+
 func (me Announce) Do() (res AnnounceResponse, err error) {
 	_url, err := url.Parse(me.TrackerUrl)
 	if err != nil {
@@ -75,7 +78,7 @@ func (me Announce) Do() (res AnnounceResponse, err error) {
 		// This is just to maintain the old behaviour that should be a timeout of 15s. Users can
 		// override it by providing their own Context. See comments elsewhere about longer timeouts
 		// acting as rate limiting overloaded trackers.
-		ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+		ctx, cancel := context.WithTimeout(context.Background(), DefaultTrackerAnnounceTimeout)
 		defer cancel()
 		me.Context = ctx
 	}
diff --git a/tracker_scraper.go b/tracker_scraper.go
index c18f21f8..21c4111b 100644
--- a/tracker_scraper.go
+++ b/tracker_scraper.go
@@ -136,13 +136,15 @@ func (me *trackerScraper) announce(ctx context.Context, event tracker.AnnounceEv
 	me.t.cl.rLock()
 	req := me.t.announceRequest(event)
 	me.t.cl.rUnlock()
-	// The default timeout is currently 15s, and that works well as backpressure on concurrent
-	// access to the tracker.
-	//ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
-	//defer cancel()
+	// The default timeout works well as backpressure on concurrent access to the tracker. Since
+	// we're passing our own Context now, we will include that timeout ourselves to maintain similar
+	// behavior to previously, albeit with this context now being cancelled when the Torrent is
+	// closed.
+	ctx, cancel := context.WithTimeout(ctx, tracker.DefaultTrackerAnnounceTimeout)
+	defer cancel()
 	me.t.logger.WithDefaultLevel(log.Debug).Printf("announcing to %q: %#v", me.u.String(), req)
 	res, err := tracker.Announce{
-		//Context:    ctx,
+		Context:    ctx,
 		HTTPProxy:  me.t.cl.config.HTTPProxy,
 		UserAgent:  me.t.cl.config.HTTPUserAgent,
 		TrackerUrl: me.trackerUrl(ip),
@@ -243,7 +245,7 @@ func (me *trackerScraper) Run() {
 }
 
 func (me *trackerScraper) announceStopped() {
-	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	ctx, cancel := context.WithTimeout(context.Background(), tracker.DefaultTrackerAnnounceTimeout)
 	defer cancel()
 	me.announce(ctx, tracker.Stopped)
 }