Merge pull request getlantern#4498 from getlantern/encodetime

uaalto · uaalto · commit e5f3927778cb · 2016-06-02T21:43:51.000+02:00
Compressed encoding of asof time for bandwidth tracking
diff --git a/src/github.com/getlantern/bandwidth/bandwidth.go b/src/github.com/getlantern/bandwidth/bandwidth.go
@@ -16,6 +16,8 @@ var (
 	quota *Quota
 	mutex sync.RWMutex
 
+	epoch = time.Date(2016, 1, 1, 0, 0, 0, 0, time.UTC)
+
 	// Updates is a channel on which one can receive updates to the Quota
 	Updates = make(chan *Quota, 100)
 )
@@ -42,7 +44,8 @@ func GetQuota() *Quota {
 //
 // <used> is the string representation of a 64-bit unsigned integer
 // <allowed> is the string representation of a 64-bit unsigned integer
-// <asof> is the 64-bit signed integer representing nanoseconds since epoch
+// <asof> is the 64-bit signed integer representing seconds since a custom
+// epoch (00:00:00 01/01/2016 UTC).
 func Track(resp *http.Response) {
 	xbq := resp.Header.Get("XBQ")
 	if xbq == "" {
@@ -71,7 +74,7 @@ func Track(resp *http.Response) {
 		log.Debugf("Malformed XBQ header %v, can't parse as of time: %v", err)
 		return
 	}
-	asof := time.Unix(0, asofInt)
+	asof := epoch.Add(time.Duration(asofInt) * time.Second)
 	mutex.Lock()
 	if quota == nil || quota.AsOf.Before(asof) {
 		quota = &Quota{allowed, used, asof}
diff --git a/src/github.com/getlantern/bandwidth/bandwidth_test.go b/src/github.com/getlantern/bandwidth/bandwidth_test.go
@@ -31,8 +31,9 @@ func TestRoundTrip(t *testing.T) {
 		assert.EqualValues(t, 500, q2.MiBAllowed)
 		assert.EqualValues(t, 6, q.MiBUsed)
 		assert.EqualValues(t, 6, q2.MiBUsed)
-		assert.EqualValues(t, time.Unix(0, 3), q.AsOf)
-		assert.EqualValues(t, time.Unix(0, 3), q2.AsOf)
+		asof := epoch.Add(3 * time.Second)
+		assert.EqualValues(t, asof, q.AsOf)
+		assert.EqualValues(t, asof, q2.AsOf)
 	}
 
 }

Original file line number	Diff line number	Diff line change
`@@ -31,8 +31,9 @@ func TestRoundTrip(t *testing.T) {`
`31`	`31`	`assert.EqualValues(t, 500, q2.MiBAllowed)`
`32`	`32`	`assert.EqualValues(t, 6, q.MiBUsed)`
`33`	`33`	`assert.EqualValues(t, 6, q2.MiBUsed)`
`34`		`- assert.EqualValues(t, time.Unix(0, 3), q.AsOf)`
`35`		`- assert.EqualValues(t, time.Unix(0, 3), q2.AsOf)`
	`34`	`+ asof := epoch.Add(3 * time.Second)`
	`35`	`+ assert.EqualValues(t, asof, q.AsOf)`
	`36`	`+ assert.EqualValues(t, asof, q2.AsOf)`
`36`	`37`	`}`
`37`	`38`
`38`	`39`	`}`