txqueue work

tcp/txqueue.go

@@ -68,9 +68,9 @@ func (tx *ringTx) Write(b []byte) (int, error) {
 	return r.WriteLimited(b, first.off)
 }
 
-// ReadPacket reads from the unsent data ring buffer and generates a new packet segment.
+// 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) NewPacketAndRead(b []byte) (int, error) {
+func (tx *ringTx) MakePacket(b []byte) (int, error) {
 	nxtpkt := (tx.lastPkt + 1) % len(tx.packets)
 	if tx.firstPkt == nxtpkt {
 		return 0, errors.New("packet queue full")

tcp/txqueue_test.go

@@ -0,0 +1,35 @@
+package tcp
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestTxQueueWrite(t *testing.T) {
+	const (
+		bufsize = 1024
+		maxPkt  = 3
+		msg     = "hello world"
+	)
+	buf := make([]byte, bufsize)
+	rtx := newRingTx(buf, maxPkt)
+
+	bufs := bytes.SplitAfter([]byte(msg), []byte("e"))
+	var data [bufsize]byte
+	for i, buf := range bufs {
+		n, err := rtx.Write(buf)
+		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)
+		}
+		n, 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])
+		}
+	}
+}