fix tests not passing for RingTx

tcp/txqueue_test.go

@@ -5,32 +5,52 @@ import (
 	"testing"
 )
 
-func TestTxQueueWrite(t *testing.T) {
+func TestTxQueue_SequentialMessages(t *testing.T) {
 	const (
-		bufsize = 1024
-		maxPkt  = 3
-		msg     = "hello world"
+		bufsize  = 2
+		maxPkt   = 1
+		msg      = "hello world"
+		startAck = 0 // this is the initial sequence number.
 	)
 	buf := make([]byte, bufsize)
-	rtx := newRingTx(buf, maxPkt)
-
-	bufs := bytes.SplitAfter([]byte(msg), []byte("e"))
+	var rtx ringTx
+	err := rtx.Reset(buf, maxPkt, startAck)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// msgs := bytes.SplitAfter([]byte(msg), []byte("e"))
+	msgs := bytes.Split([]byte(msg), []byte(""))
 	var data [bufsize]byte
-	for i, buf := range bufs {
-		n, err := rtx.Write(buf)
+	prevSeq := Value(startAck)
+	for i, msg := range msgs {
+		n, err := rtx.Write(msg)
 		if err != nil {
 			t.Fatalf("writing packet %d: %s", i, err)
-		} else if n != len(buf) {
-			t.Fatalf("want %d written, got %d", len(buf), n)
+		} else if n != len(msg) {
+			t.Fatalf("want %d written, got %d", len(msg), n)
 		}
-
-		n, err = rtx.MakePacket(data[:])
+		unsent := rtx.Buffered()
+		if len(msg) != unsent {
+			t.Fatalf("want %d unsent buffered, got %d", unsent, len(msg))
+		}
+		sent := rtx.BufferedSent()
+		if sent > 0 {
+			t.Fatalf("want 0 bytes sent, got %d", sent)
+		}
+		n, seq, err := rtx.MakePacket(data[:])
 		if err != nil {
 			t.Fatalf("making packet %d: %s", i, err)
-		} else if n != len(buf) {
-			t.Fatalf("want %d packet read, got %d", len(buf), n)
-		} else if !bytes.Equal(buf, data[:n]) {
-			t.Fatalf("want data %q, got data read %q", buf, data[:n])
+		} else if n != len(msg) {
+			t.Fatalf("want %d packet read, got %d", len(msg), n)
+		} else if !bytes.Equal(msg, data[:n]) {
+			t.Fatalf("want data %q, got data read %q", msg, data[:n])
+		} else if seq != prevSeq {
+			t.Fatalf("want seq %d, got %d", prevSeq, seq)
+		}
+		prevSeq += Value(n)
+		err = rtx.RecvACK(prevSeq)
+		if err != nil {
+			t.Fatal(err)
 		}
 	}
 }