Restructure stats into delta, mask, and aggregate layers

rx.go

@@ -110,14 +110,14 @@ func fillBack(frames, bytes []uint64) {
 }
 
 type rxWorker struct {
-	fd        int
-	batch     int
-	stream    uint16
-	spec      *frameSpec
-	stats     *rxStats
-	loss      *lossWindow
-	measuring *atomic.Bool
-	ready     *sync.WaitGroup
+	fd     int
+	batch  int
+	stream uint16
+	spec   *frameSpec
+	stats  *rxStats
+	loss   *lossWindow
+	masked *atomic.Bool
+	ready  *sync.WaitGroup
 }
 
 func (w *rxWorker) run(done *atomic.Bool) {
@@ -133,12 +133,13 @@ func (w *rxWorker) run(done *atomic.Bool) {
 	w.ready.Done()
 
 	for !done.Load() {
-		// One flag load covers the batch: failures seen while a cable measure
-		// runs are its own link blip and are never counted.
-		quiet := w.measuring.Load()
+		// The worker just counts; the mask gate above decides what a masked
+		// tick's counts are worth. One flag load covers the batch for the loss
+		// window, whose gap charges outlive the tick they happened in.
+		masked := w.masked.Load()
 		n, err := recvmmsg(w.fd, hdrs, unix.MSG_WAITFORONE)
 		if n <= 0 {
-			if err != nil && err != unix.EAGAIN && err != unix.EINTR && !quiet {
+			if err != nil && err != unix.EAGAIN && err != unix.EINTR {
 				w.stats.rxErrs.Add(1)
 			}
 			continue
@@ -149,9 +150,6 @@ func (w *rxWorker) run(done *atomic.Bool) {
 			buf := bufs[i][:int(hdrs[i].len)]
 			p, st := parseHeader(buf)
 			if st != hdrOK {
-				if quiet {
-					continue
-				}
 				if st == hdrForeign {
 					w.stats.badMagic.Add(1)
 				} else {
@@ -165,22 +163,18 @@ func (w *rxWorker) run(done *atomic.Bool) {
 			// The ethertype this socket is bound to already says which stream the
 			// frame belongs to, so a header naming another one is damaged, as is a
 			// sequence number the sender never reached.
-			if p.stream != w.stream || !w.loss.observe(p.seq, quiet) {
-				if !quiet {
-					w.stats.badHdr.Add(1)
-				}
+			if p.stream != w.stream || !w.loss.observe(p.seq, masked) {
+				w.stats.badHdr.Add(1)
 				continue
 			}
 
 			want, ok := w.spec.expectedCRC(p.patIdx, p.payLen)
 			if !ok {
-				if !quiet {
-					w.stats.badLen.Add(1)
-				}
+				w.stats.badLen.Add(1)
 				continue
 			}
 			pay := buf[minFrame : minFrame+p.payLen]
-			if crc32.Checksum(pay, crcTable) != want && !quiet {
+			if crc32.Checksum(pay, crcTable) != want {
 				w.stats.crcErr.Add(1)
 			}
 		}