fix tests finally

tcp/txqueue.go

@@ -46,182 +46,183 @@ type ringidx struct {
 
 // Reset resets the RingTx's internal state to use buf as the main ring buffer and creates or reuses
 // the packet ring buffer.
-func (rx *ringTx) Reset(buf []byte, maxqueuedPackets int, seq Value) error {
+func (rtx *ringTx) Reset(buf []byte, maxqueuedPackets int, seq Value) error {
 	if maxqueuedPackets <= 0 {
 		return errors.New("queued packets <=0")
 	} else if len(buf) < minBufferSize || len(buf) < maxqueuedPackets {
 		return errors.New("invalid buffer size")
 	}
-	if cap(rx.packets) < maxqueuedPackets {
-		rx.packets = make([]ringidx, maxqueuedPackets)
+	if cap(rtx.packets) < maxqueuedPackets {
+		rtx.packets = make([]ringidx, maxqueuedPackets)
 	}
-	*rx = ringTx{
+	*rtx = ringTx{
 		rawbuf:  buf,
-		packets: rx.packets[:maxqueuedPackets],
+		packets: rtx.packets[:maxqueuedPackets],
 		seq:     seq,
 	}
-	for i := range rx.packets {
-		rx.packets[i].markRcvd()
+	for i := range rtx.packets {
+		rtx.packets[i].markRcvd()
 	}
 	return nil
 }
 
 // ResetOrReuse is identical to a call to [ringTx.Reset] with the additional detail that
 // the zero value of buf (nil) and maxQueuedPackets (0) will selectively reuse existing data buffer and/or packet index buffer.
-func (rx *ringTx) ResetOrReuse(buf []byte, maxQueuedPackets int, ack Value) error {
+func (rtx *ringTx) ResetOrReuse(buf []byte, maxQueuedPackets int, ack Value) error {
 	if buf == nil {
-		buf = rx.rawbuf
+		buf = rtx.rawbuf
 	}
 	if maxQueuedPackets == 0 {
-		maxQueuedPackets = len(rx.packets)
+		maxQueuedPackets = len(rtx.packets)
 	}
-	return rx.Reset(buf, maxQueuedPackets, ack)
+	return rtx.Reset(buf, maxQueuedPackets, ack)
 }
 
 // Size returns the total storage space of the transmission buffer.
-func (tx *ringTx) Size() int { return len(tx.rawbuf) }
+func (rtx *ringTx) Size() int { return len(rtx.rawbuf) }
 
 // Free returns the total available space for Write calls.
-func (tx *ringTx) Free() int {
-	r := tx.sentAndUnsentBuffer()
+func (rtx *ringTx) Free() int {
+	r := rtx.sentAndUnsentBuffer()
 	return r.Free()
 }
 
-// Buffered returns the amount of unsent bytes.
-func (tx *ringTx) Buffered() int {
-	r, _ := tx.unsentRing()
+// Buffered returns the amount of written but unsent bytes.
+func (rtx *ringTx) Buffered() int {
+	r, _ := rtx.unsentRing()
 	return r.Buffered()
 }
 
 // BufferedSent returns the total amount of bytes sent but not acked.
-func (tx *ringTx) BufferedSent() int {
-	r, _ := tx.sentRing()
+func (rtx *ringTx) BufferedSent() int {
+	r, _ := rtx.sentRing()
 	return r.Buffered()
 }
 
 // Write writes data to the underlying unsent data ring buffer.
-func (tx *ringTx) Write(b []byte) (n int, err error) {
-	r, lim := tx.unsentRing()
+func (rtx *ringTx) Write(b []byte) (n int, err error) {
+	r, lim := rtx.unsentRing()
 	n, err = r.WriteLimited(b, lim)
 	if err != nil {
 		return 0, err
 	}
-	tx.unsentend = tx.addEnd(tx.unsentend, n)
+	rtx.unsentend = rtx.addEnd(rtx.unsentend, n)
 	return n, err
 }
 
 // MakePacket reads from the unsent data ring buffer and generates a new packet segment.
 // It fails if the sent packet queue is full.
-func (tx *ringTx) MakePacket(b []byte) (int, Value, error) {
-	nxtpkt := tx.nextPkt()
-	if tx.nextPkt() < 0 {
+func (rtx *ringTx) MakePacket(b []byte) (int, Value, error) {
+	nxtpkt := rtx.nextPkt()
+	if rtx.nextPkt() < 0 {
 		return 0, 0, errors.New("queue full")
 	}
-	r, _ := tx.unsentRing()
+	r, _ := rtx.unsentRing()
 	start := r.Off
 	n, err := r.Read(b)
 	if err != nil {
 		return n, 0, err
 	}
-	pkt := &tx.packets[nxtpkt]
+	pkt := &rtx.packets[nxtpkt]
 
-	off := tx.addEnd(tx.unsentoff, n)
-	tx.unsentoff = off
-	tx.sentend = off
-	if off == tx.unsentend {
-		tx.unsentend = 0 // Mark unsent as being empty.
+	off := rtx.addEnd(rtx.unsentoff, n)
+	rtx.unsentoff = off
+	rtx.sentend = off
+	if off == rtx.unsentend {
+		rtx.unsentend = 0 // Mark unsent as being empty.
 	}
 	pkt.off = start
 	pkt.end = off
 
 	// Sequence number updates.
-	oldseq := tx.seq
+	oldseq := rtx.seq
 	newseq := Add(oldseq, Size(n))
-	tx.seq = newseq
+	rtx.seq = newseq
 	pkt.seq = newseq
 	return n, oldseq, nil
 }
 
 // RecvSegment processes an incoming segment and updates the sent packet queue
-func (tx *ringTx) RecvACK(ack Value) error {
-	if ack.LessThan(tx.seq) {
+func (rtx *ringTx) RecvACK(ack Value) error {
+	if ack.LessThan(rtx.seq) {
 		return errors.New("old packet")
 	}
-	first := tx.firstPkt()
+	first := rtx.firstPkt()
 	if first < 0 {
 		return errors.New("no packets to ack")
 	}
-	hiSeq := tx.pkt(first).seq
-	for i := 0; i < len(tx.packets); i++ {
-		pkt := &tx.packets[i]
+	hiSeq := rtx.pkt(first).seq
+	for i := 0; i < len(rtx.packets); i++ {
+		pkt := &rtx.packets[i]
 		if pkt.sent() && pkt.seq.LessThanEq(ack) {
-			if hiSeq.LessThan(pkt.seq) {
-				tx.sentoff = pkt.end
+			if hiSeq.LessThanEq(pkt.seq) {
+				rtx.sentoff = pkt.end
 				hiSeq = pkt.seq
 			}
 			pkt.markRcvd()
 		}
 	}
-	firstAcked := !tx.pkt(first).sent()
-	if firstAcked && tx.sentoff == tx.sentend {
+	firstAcked := !rtx.pkt(first).sent()
+	if firstAcked && rtx.sentoff == rtx.sentend {
 		// All data acked.
-		tx.sentend = 0
+		rtx.sentend = 0
+		rtx.consolidateBufs()
 	}
 	return nil
 }
 
-func (tx *ringTx) sentAndUnsentBuffer() internal.Ring {
-	end := tx.unsentend
+func (rtx *ringTx) sentAndUnsentBuffer() internal.Ring {
+	end := rtx.unsentend
 	if end == 0 {
-		end = tx.sentend
+		end = rtx.sentend
 	}
-	return internal.Ring{Buf: tx.rawbuf, Off: tx.sentoff, End: end}
+	return internal.Ring{Buf: rtx.rawbuf, Off: rtx.sentoff, End: end}
 }
 
-func (tx *ringTx) unsentRing() (internal.Ring, int) {
-	return tx.ring(tx.unsentoff, tx.unsentend), tx.sentoff
+func (rtx *ringTx) unsentRing() (internal.Ring, int) {
+	return rtx.ring(rtx.unsentoff, rtx.unsentend), rtx.sentoff
 }
 
-func (tx *ringTx) sentRing() (internal.Ring, int) {
-	return tx.ring(tx.sentoff, tx.sentend), tx.unsentoff // unsentoff should match with sentend, so no writes can be performed to sentring.
+func (rtx *ringTx) sentRing() (internal.Ring, int) {
+	return rtx.ring(rtx.sentoff, rtx.sentend), rtx.unsentoff // unsentoff should match with sentend, so no writes can be performed to sentring.
 }
 
-func (tx *ringTx) ring(off, end int) internal.Ring {
-	return internal.Ring{Buf: tx.rawbuf, Off: off, End: end}
+func (rtx *ringTx) ring(off, end int) internal.Ring {
+	return internal.Ring{Buf: rtx.rawbuf, Off: off, End: end}
 }
 
 // addEnd adds two integers together and wraps the value around the ring's buffer size.
 // Result of addEnd will never be 0 unless arguments are (0,0).
-func (tx *ringTx) addEnd(a, b int) int {
+func (rtx *ringTx) addEnd(a, b int) int {
 	result := a + b
-	if result > len(tx.rawbuf) {
-		result -= len(tx.rawbuf)
+	if result > len(rtx.rawbuf) {
+		result -= len(rtx.rawbuf)
 	}
 	return result
 }
 
-func (tx *ringTx) addOff(a, b int) int {
+func (rtx *ringTx) addOff(a, b int) int {
 	result := a + b
-	if result >= len(tx.rawbuf) {
-		result -= len(tx.rawbuf)
+	if result >= len(rtx.rawbuf) {
+		result -= len(rtx.rawbuf)
 	}
 	return result
 }
 
-func (tx *ringTx) pkt(i int) *ringidx {
+func (rtx *ringTx) pkt(i int) *ringidx {
 	if i == -1 {
-		return &tx.emptyRing
-	} else if i < 0 || i >= len(tx.packets) {
+		return &rtx.emptyRing
+	} else if i < 0 || i >= len(rtx.packets) {
 		panic("invalid packet index")
 	}
-	return &tx.packets[i]
+	return &rtx.packets[i]
 }
 
-func (tx *ringTx) firstPkt() int {
+func (rtx *ringTx) firstPkt() int {
 	var seq Value
 	idx := -1
-	for i := 0; i < len(tx.packets); i++ {
-		pkt := &tx.packets[i]
+	for i := 0; i < len(rtx.packets); i++ {
+		pkt := &rtx.packets[i]
 		if pkt.sent() && (idx == -1 || seq.LessThan(pkt.seq)) {
 			seq = pkt.seq
 			idx = i
@@ -230,11 +231,11 @@ func (tx *ringTx) firstPkt() int {
 	return idx
 }
 
-func (tx *ringTx) lastPkt() int {
+func (rtx *ringTx) lastPkt() int {
 	var seq Value
 	idx := -1
-	for i := 0; i < len(tx.packets); i++ {
-		pkt := &tx.packets[i]
+	for i := 0; i < len(rtx.packets); i++ {
+		pkt := &rtx.packets[i]
 		if pkt.sent() && (idx == -1 || pkt.seq.LessThan(seq)) {
 			seq = pkt.seq
 			idx = i
@@ -243,10 +244,10 @@ func (tx *ringTx) lastPkt() int {
 	return idx
 }
 
-func (tx *ringTx) nextPkt() int {
+func (rtx *ringTx) nextPkt() int {
 	idx := -1
-	for i := 0; i < len(tx.packets); i++ {
-		pkt := &tx.packets[i]
+	for i := 0; i < len(rtx.packets); i++ {
+		pkt := &rtx.packets[i]
 		if !pkt.sent() {
 			idx = i
 			break
@@ -255,6 +256,18 @@ func (tx *ringTx) nextPkt() int {
 	return idx
 }
 
+func (rtx *ringTx) consolidateBufs() {
+	unsentEmpty := rtx.unsentend == 0
+	sentEmpty := rtx.sentend == 0
+	if unsentEmpty && sentEmpty {
+		// reset start of buffers.
+		rtx.sentoff = 0
+		rtx.unsentoff = 0
+	}
+}
+
+func (rtx *ringTx) currentSeq() Value { return rtx.seq }
+
 // lims returns the limits of free|sent|unsent buffers.
 // Example:
 //