fix trace replay issue

go/cmd/trace/trace.go

@@ -90,7 +90,7 @@ func main() {
 		}
 	} else if *prettyFlag {
 		if err := PrintPretty(tf); err != nil {
-			fmt.Fprintf(os.Stderr, "error printing json: %v\n", err)
+			fmt.Fprintf(os.Stderr, "error printing pretty: %v\n", err)
 			os.Exit(1)
 		}
 	}

go/models/op.go

@@ -6,9 +6,3 @@ type Op interface {
 	Pack(w io.Writer) (int, error)
 	Unpack(r io.Reader) (int, error)
 }
-
-type NoOp struct {
-}
-
-func (n *NoOp) Pack(w io.Writer) (int, error)   { return 0, nil }
-func (n *NoOp) Unpack(r io.Reader) (int, error) { return 0, nil }

go/models/trace/filter_membatch.go

@@ -10,7 +10,7 @@ import (
 
 // OpMemBatch is a collection of reads and writes that occured within a basic block
 type OpMemBatch struct {
-	models.NoOp
+	OpNop
 	Ops []models.Op
 }
 

go/models/trace/ops.go

@@ -42,7 +42,7 @@ func packOps(w io.Writer, ops []models.Op) (total int, err error) {
 func unpackOps(r io.Reader, count int) (ops []models.Op, total int, err error) {
 	ops = make([]models.Op, count)
 	for i := 0; i < count; i++ {
-		op, n, err := Unpack(r)
+		op, n, err := Unpack(r, true)
 		if err != nil {
 			return ops, total + n, errors.Wrap(err, "unpacking op list")
 		} else {
@@ -53,7 +53,7 @@ func unpackOps(r io.Reader, count int) (ops []models.Op, total int, err error) {
 	return ops, total, nil
 }
 
-func Unpack(r io.Reader) (models.Op, int, error) {
+func Unpack(r io.Reader, nested bool) (models.Op, int, error) {
 	var tmp [1]byte
 	if _, err := r.Read(tmp[:]); err != nil {
 		return nil, 0, err
@@ -89,6 +89,9 @@ func Unpack(r io.Reader) (models.Op, int, error) {
 	default:
 		return nil, 0, errors.Errorf("Unknown op: %d", tmp[0])
 	}
+	if nested && (tmp[0] == OP_FRAME || tmp[0] == OP_KEYFRAME) {
+		return nil, 0, errors.Errorf("fatal: nested frame")
+	}
 	n, err := op.Unpack(r)
 	return op, n + 1, err
 }

go/models/trace/ops_test.go

@@ -40,7 +40,7 @@ func TestOpFrame(t *testing.T) {
 	if _, err := testFrame.Pack(&buf); err != nil {
 		t.Fatal(err)
 	}
-	op, _, err := Unpack(&buf)
+	op, _, err := Unpack(&buf, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -49,7 +49,7 @@ func TestOpFrame(t *testing.T) {
 	if _, err := op.Pack(&buf2); err != nil {
 		t.Fatal(err)
 	}
-	_, _, err = Unpack(&buf2)
+	_, _, err = Unpack(&buf2, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -71,7 +71,7 @@ func BenchmarkUnpack(b *testing.B) {
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		r.Seek(0, 0)
-		if _, _, err := Unpack(r); err != nil {
+		if _, _, err := Unpack(r, false); err != nil {
 			b.Fatal(err)
 		}
 	}

go/models/trace/tracefile.go

@@ -123,7 +123,7 @@ func NewReader(r io.ReadCloser) (*TraceReader, error) {
 }
 
 func (t *TraceReader) Next() (models.Op, error) {
-	op, _, err := Unpack(t.zr)
+	op, _, err := Unpack(t.zr, false)
 	return op, err
 }