From 7fc9d5938188cb57fabf3dc32c1c9b88611cfc9b Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 8 Jan 2017 19:30:50 +0700
Subject: [PATCH] determine if a received packet is retransmittable

---
 packet_unpacker.go      |  4 ----
 unpacked_packet.go      | 27 ++++++++++++++++++++++++
 unpacked_packet_test.go | 46 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 73 insertions(+), 4 deletions(-)
 create mode 100644 unpacked_packet.go
 create mode 100644 unpacked_packet_test.go

diff --git a/packet_unpacker.go b/packet_unpacker.go
index 3434751b..cec85ed7 100644
--- a/packet_unpacker.go
+++ b/packet_unpacker.go
@@ -11,10 +11,6 @@ import (
 	"github.com/lucas-clemente/quic-go/qerr"
 )
 
-type unpackedPacket struct {
-	frames []frames.Frame
-}
-
 type packetUnpacker struct {
 	version protocol.VersionNumber
 	aead    crypto.AEAD
diff --git a/unpacked_packet.go b/unpacked_packet.go
new file mode 100644
index 00000000..80792047
--- /dev/null
+++ b/unpacked_packet.go
@@ -0,0 +1,27 @@
+package quic
+
+import "github.com/lucas-clemente/quic-go/frames"
+
+type unpackedPacket struct {
+	frames []frames.Frame
+}
+
+func (u *unpackedPacket) IsRetransmittable() bool {
+	for _, f := range u.frames {
+		switch f.(type) {
+		case *frames.StreamFrame:
+			return true
+		case *frames.RstStreamFrame:
+			return true
+		case *frames.WindowUpdateFrame:
+			return true
+		case *frames.BlockedFrame:
+			return true
+		case *frames.PingFrame:
+			return true
+		case *frames.GoawayFrame:
+			return true
+		}
+	}
+	return false
+}
diff --git a/unpacked_packet_test.go b/unpacked_packet_test.go
new file mode 100644
index 00000000..82112a26
--- /dev/null
+++ b/unpacked_packet_test.go
@@ -0,0 +1,46 @@
+package quic
+
+import (
+	"github.com/lucas-clemente/quic-go/frames"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Unpacked packet", func() {
+	var packet *unpackedPacket
+	BeforeEach(func() {
+		packet = &unpackedPacket{}
+	})
+
+	It("says that an empty packet is not retransmittable", func() {
+		Expect(packet.IsRetransmittable()).To(BeFalse())
+	})
+
+	It("detects the frame types", func() {
+		packet.frames = []frames.Frame{&frames.AckFrame{}}
+		Expect(packet.IsRetransmittable()).To(BeFalse())
+		packet.frames = []frames.Frame{&frames.BlockedFrame{}}
+		Expect(packet.IsRetransmittable()).To(BeTrue())
+		packet.frames = []frames.Frame{&frames.GoawayFrame{}}
+		Expect(packet.IsRetransmittable()).To(BeTrue())
+		packet.frames = []frames.Frame{&frames.PingFrame{}}
+		Expect(packet.IsRetransmittable()).To(BeTrue())
+		packet.frames = []frames.Frame{&frames.StreamFrame{}}
+		Expect(packet.IsRetransmittable()).To(BeTrue())
+		packet.frames = []frames.Frame{&frames.RstStreamFrame{}}
+		Expect(packet.IsRetransmittable()).To(BeTrue())
+		packet.frames = []frames.Frame{&frames.StopWaitingFrame{}}
+		Expect(packet.IsRetransmittable()).To(BeFalse())
+		packet.frames = []frames.Frame{&frames.WindowUpdateFrame{}}
+		Expect(packet.IsRetransmittable()).To(BeTrue())
+	})
+
+	It("says that a packet is retransmittable if it contains one retransmittable frame", func() {
+		packet.frames = []frames.Frame{
+			&frames.AckFrame{},
+			&frames.WindowUpdateFrame{},
+			&frames.StopWaitingFrame{},
+		}
+		Expect(packet.IsRetransmittable()).To(BeTrue())
+	})
+})