From 57caef8937eaee864aaa36e6571e2d33983d8999 Mon Sep 17 00:00:00 2001
From: Dan Kortschak <dan@kortschak.io>
Date: Fri, 19 Oct 2018 21:11:02 +1030
Subject: [PATCH] revid: clean up output clips some more

The low volume throttle is removed since that's the job of the kernel's scheduler.
---
 revid/revid.go | 51 ++++++++++++++++++++++++--------------------------
 1 file changed, 24 insertions(+), 27 deletions(-)

diff --git a/revid/revid.go b/revid/revid.go
index 1b150f62..1e532662 100644
--- a/revid/revid.go
+++ b/revid/revid.go
@@ -65,7 +65,7 @@ const (
 	rtmpConnectionTimout    = 10
 	outputChanSize          = 1000
 	cameraRetryPeriod       = 5 * time.Second
-	sendFailedDelay         = 5
+	sendFailedDelay         = 5 * time.Millisecond
 	maxSendFailedErrorCount = 500
 	clipSizeThreshold       = 11
 	rtmpConnectionMaxTries  = 5
@@ -317,29 +317,26 @@ func (r *Revid) Stop() {
 // outputClips takes the clips produced in the packClips method and outputs them
 // to the desired output defined in the revid config
 func (r *Revid) outputClips() {
-	now := time.Now()
-	prevTime := now
-	bytes := 0
-	delay := 0
+	lastTime := time.Now()
+	var count int
+loop:
 	for r.isRunning {
-		// Here we slow things down as much as we can to decrease cpu usage
-		switch {
-		case r.buffer.Len() < 2:
-			delay++
-			time.Sleep(time.Duration(delay) * time.Millisecond)
-		case delay > 0:
-			delay--
-		}
 		// If the ring buffer has something we can read and send off
 		chunk, err := r.buffer.Next(readTimeout)
-		if err != nil || !r.isRunning {
-			if err == io.EOF {
-				break
-			}
+		switch err {
+		case nil:
+			// Do nothing.
+		case ring.ErrTimeout:
+			r.config.Logger.Log(smartlogger.Warning, pkg+"ring buffer read timeout")
 			continue
+		default:
+			r.config.Logger.Log(smartlogger.Error, pkg+"unexpected error", "error", err.Error())
+			fallthrough
+		case io.EOF:
+			break loop
 		}
 
-		bytes += chunk.Len()
+		count += chunk.Len()
 		r.config.Logger.Log(smartlogger.Debug, pkg+"about to send")
 		err = r.destination.load(chunk)
 		if err != nil {
@@ -350,16 +347,16 @@ func (r *Revid) outputClips() {
 			r.config.Logger.Log(smartlogger.Debug, pkg+"sent clip")
 		}
 
-		if r.isRunning && err != nil && chunk.Len() > 11 {
+		if err != nil && chunk.Len() > 11 {
 			r.config.Logger.Log(smartlogger.Debug, pkg+"send failed, trying again")
 			// Try and send again
 			err = r.destination.send()
 			r.config.Logger.Log(smartlogger.Error, pkg+"destination send error", "error", err.Error())
 
 			// if there's still an error we try and reconnect, unless we're stopping
-			for r.isRunning && err != nil {
-				r.config.Logger.Log(smartlogger.Debug, pkg+"send failed a again, trying to reconnect...")
-				time.Sleep(time.Duration(sendFailedDelay) * time.Millisecond)
+			for err != nil {
+				r.config.Logger.Log(smartlogger.Debug, pkg+"send failed again, trying to reconnect...")
+				time.Sleep(sendFailedDelay)
 				r.config.Logger.Log(smartlogger.Error, pkg+"send failed with error", "error", err.Error())
 
 				if rs, ok := r.destination.(restarter); ok {
@@ -387,15 +384,15 @@ func (r *Revid) outputClips() {
 		r.config.Logger.Log(smartlogger.Debug, pkg+"done reading that clip from ring buffer")
 
 		// Log some information regarding bitrate and ring buffer size if it's time
-		now = time.Now()
-		deltaTime := now.Sub(prevTime)
+		now := time.Now()
+		deltaTime := now.Sub(lastTime)
 		if deltaTime > bitrateTime {
 			// FIXME(kortschak): For subsecond deltaTime, this will give infinite bitrate.
-			r.bitrate = int(float64(bytes*8) / float64(deltaTime/time.Second))
+			r.bitrate = int(float64(count*8) / float64(deltaTime/time.Second))
 			r.config.Logger.Log(smartlogger.Debug, pkg+"bitrate (bits/s)", "bitrate", r.bitrate)
 			r.config.Logger.Log(smartlogger.Debug, pkg+"ring buffer size", "value", r.buffer.Len())
-			prevTime = now
-			bytes = 0
+			lastTime = now
+			count = 0
 		}
 	}
 	r.config.Logger.Log(smartlogger.Info, pkg+"not outputting clips anymore")