Combine HeaderForm and PacketKind enums into a single enum

quic/packets.nim

@@ -4,14 +4,12 @@ import strformat
 import bits
 
 type
-  HeaderForm* = enum
-    headerShort
-    headerLong
   PacketKind* = enum
     packetInitial
     packet0RTT
     packetHandshake
     packetRetry
+    packetShort
     packetVersionNegotiation
   PacketHeader* = object
     bytes: seq[byte]
@@ -25,12 +23,6 @@ proc newPacketHeader*(bytes: seq[byte]): PacketHeader =
 proc bytes*(header: PacketHeader): seq[byte] =
   header.bytes
 
-proc form*(header: PacketHeader): HeaderForm =
-  HeaderForm(header.bytes[0].bits[0])
-
-proc `form=`*(header: var PacketHeader, form: HeaderForm) =
-  header.bytes[0].bits[0] = Bit(form)
-
 proc version*(header: PacketHeader): uint32 =
   result.bytes[0] = header.bytes[1]
   result.bytes[1] = header.bytes[2]
@@ -44,7 +36,9 @@ proc `version=`*(header: var PacketHeader, version: uint32) =
   header.bytes[4] = version.bytes[3]
 
 proc kind*(header: PacketHeader): PacketKind =
-  if header.version == 0:
+  if header.bytes[0].bits[0] == 0:
+    result = packetShort
+  elif header.version == 0:
     result = packetVersionNegotiation
   else:
     var kind: uint8
@@ -88,25 +82,22 @@ proc `$`*(id: ConnectionId): string =
   "0x" & cast[string](id).toHex
 
 proc `$`*(header: PacketHeader): string =
-  case header.form:
-  of headerShort: fmt"(form: {header.form})"
-  of headerLong:
-    case header.kind:
-    of packetVersionNegotiation:
-      "(" &
-        fmt"form: {header.form}, " &
-        fmt"kind: {header.kind}, " &
-        fmt"destination: {header.destination}, " &
-        fmt"source: {header.source}, " &
-        fmt"supportedVersion: {header.supportedVersion}" &
-      ")"
-    else:
-      "(" &
-        fmt"form: {header.form}, " &
-        fmt"kind: {header.kind}, " &
-        fmt"destination: {header.destination}, " &
-        fmt"source: {header.source}" &
-      ")"
+  case header.kind:
+  of packetShort:
+    fmt"(kind: {header.kind})"
+  of packetVersionNegotiation:
+    "(" &
+      fmt"kind: {header.kind}, " &
+      fmt"destination: {header.destination}, " &
+      fmt"source: {header.source}, " &
+      fmt"supportedVersion: {header.supportedVersion}" &
+    ")"
+  else:
+    "(" &
+      fmt"kind: {header.kind}, " &
+      fmt"destination: {header.destination}, " &
+      fmt"source: {header.source}" &
+    ")"
 
 proc `==`*(x: ConnectionId, y: ConnectionId): bool {.borrow.}
 

tests/quic/testPackets.nim

@@ -5,14 +5,12 @@ import quic/bits
 
 suite "packet header":
 
-  test "first bit of the header indicates its form":
-    check newPacketHeader(@[0b01000000'u8]).form == headerShort
-    check newPacketHeader(@[0b11000000'u8]).form == headerLong
-
-  test "header form can be set":
-    var header = newPacketHeader(@[0b01000000'u8])
-    header.form = headerLong
-    check header.bytes[0].bits[0] == 1
+  test "first bit of the header indicates short/long form":
+    var datagram = newSeq[byte](4096)
+    datagram[0] = 0b01000000'u8
+    check newPacketHeader(datagram).kind == packetShort
+    datagram[0] = 0b11000000'u8
+    check newPacketHeader(datagram).kind != packetShort
 
   test "second bit of the header should always be 1":
     expect Exception:
@@ -21,7 +19,7 @@ suite "packet header":
 suite "short headers":
 
   test "conversion to string":
-    check $newPacketHeader(@[0b01000000'u8]) == "(form: headerShort)"
+    check $newPacketHeader(@[0b01000000'u8]) == "(kind: packetShort)"
 
 suite "long headers":
 
@@ -97,7 +95,6 @@ suite "long headers":
       source.len.uint8 & source
     )
     check $header == "(" &
-      "form: headerLong, " &
       "kind: packetInitial, " &
       "destination: 0xAABBCC, " &
       "source: 0xDDEEFF" &
@@ -140,7 +137,6 @@ suite "long headers":
         version1
       )
       check $header == "(" &
-        "form: headerLong, " &
         "kind: packetVersionNegotiation, " &
         "destination: 0xAABBCC, " &
         "source: 0xDDEEFF, " &