Remove bitmaskCodec (#2792)

Author: StephenButtolph

network/peer/msg_length.go

@@ -12,29 +12,20 @@ import (
 )
 
 var (
-	errInvalidMaxMessageLength  = errors.New("invalid maximum message length")
 	errInvalidMessageLength     = errors.New("invalid message length")
 	errMaxMessageLengthExceeded = errors.New("maximum message length exceeded")
 )
 
-// Used to mask the most significant bit that was used to indicate that the
-// message format uses protocol buffers.
-//
-// TODO: Once the v1.11 is activated, this mask should be removed.
-const bitmaskCodec = uint32(1 << 31)
-
 // Assumes the specified [msgLen] will never >= 1<<31.
 func writeMsgLen(msgLen uint32, maxMsgLen uint32) ([wrappers.IntLen]byte, error) {
-	if maxMsgLen >= bitmaskCodec {
+	if msgLen > maxMsgLen {
 		return [wrappers.IntLen]byte{}, fmt.Errorf(
-			"%w; maximum message length must be <%d to be able to embed codec information at most significant bit",
-			errInvalidMaxMessageLength,
-			bitmaskCodec,
+			"%w; the message length %d exceeds the specified limit %d",
+			errMaxMessageLengthExceeded,
+			msgLen,
+			maxMsgLen,
 		)
 	}
-	if msgLen > maxMsgLen {
-		return [wrappers.IntLen]byte{}, fmt.Errorf("%w; the message length %d exceeds the specified limit %d", errMaxMessageLengthExceeded, msgLen, maxMsgLen)
-	}
 
 	b := [wrappers.IntLen]byte{}
 	binary.BigEndian.PutUint32(b[:], msgLen)
@@ -44,13 +35,6 @@ func writeMsgLen(msgLen uint32, maxMsgLen uint32) ([wrappers.IntLen]byte, error)
 
 // Assumes the read [msgLen] will never >= 1<<31.
 func readMsgLen(b []byte, maxMsgLen uint32) (uint32, error) {
-	if maxMsgLen >= bitmaskCodec {
-		return 0, fmt.Errorf(
-			"%w; maximum message length must be <%d to be able to embed codec information at most significant bit",
-			errInvalidMaxMessageLength,
-			bitmaskCodec,
-		)
-	}
 	if len(b) != wrappers.IntLen {
 		return 0, fmt.Errorf(
 			"%w; readMsgLen only supports 4 bytes (got %d bytes)",
@@ -61,12 +45,6 @@ func readMsgLen(b []byte, maxMsgLen uint32) (uint32, error) {
 
 	// parse the message length
 	msgLen := binary.BigEndian.Uint32(b)
-
-	// Because we always use proto messages, there's no need to check the most
-	// significant bit to inspect the message format. So, we just zero the proto
-	// flag.
-	msgLen &^= bitmaskCodec
-
 	if msgLen > maxMsgLen {
 		return 0, fmt.Errorf(
 			"%w; the message length %d exceeds the specified limit %d",

network/peer/msg_length_test.go

@@ -21,19 +21,9 @@ func TestWriteMsgLen(t *testing.T) {
 		expectedErr error
 	}{
 		{
-			msgLen:      math.MaxUint32,
-			msgLimit:    math.MaxUint32,
-			expectedErr: errInvalidMaxMessageLength,
-		},
-		{
-			msgLen:      bitmaskCodec,
-			msgLimit:    bitmaskCodec,
-			expectedErr: errInvalidMaxMessageLength,
-		},
-		{
-			msgLen:      bitmaskCodec - 1,
-			msgLimit:    bitmaskCodec - 1,
-			expectedErr: nil,
+			msgLen:      constants.DefaultMaxMessageSize,
+			msgLimit:    1,
+			expectedErr: errMaxMessageLengthExceeded,
 		},
 		{
 			msgLen:      constants.DefaultMaxMessageSize,
@@ -45,11 +35,6 @@ func TestWriteMsgLen(t *testing.T) {
 			msgLimit:    constants.DefaultMaxMessageSize,
 			expectedErr: nil,
 		},
-		{
-			msgLen:      constants.DefaultMaxMessageSize,
-			msgLimit:    1,
-			expectedErr: errMaxMessageLengthExceeded,
-		},
 	}
 	for _, tv := range tt {
 		msgLenBytes, err := writeMsgLen(tv.msgLen, tv.msgLimit)
@@ -73,39 +58,27 @@ func TestReadMsgLen(t *testing.T) {
 		expectedErr    error
 		expectedMsgLen uint32
 	}{
-		{
-			msgLenBytes:    []byte{0xFF, 0xFF, 0xFF, 0xFF},
-			msgLimit:       math.MaxUint32,
-			expectedErr:    errInvalidMaxMessageLength,
-			expectedMsgLen: 0,
-		},
 		{
 			msgLenBytes:    []byte{0b11111111, 0xFF},
 			msgLimit:       math.MaxInt32,
 			expectedErr:    errInvalidMessageLength,
 			expectedMsgLen: 0,
 		},
 		{
-			msgLenBytes:    []byte{0b11111111, 0xFF, 0xFF, 0xFF},
+			msgLenBytes:    []byte{0xFF, 0xFF, 0xFF, 0xFF},
 			msgLimit:       constants.DefaultMaxMessageSize,
 			expectedErr:    errMaxMessageLengthExceeded,
 			expectedMsgLen: 0,
 		},
 		{
-			msgLenBytes:    []byte{0b11111111, 0xFF, 0xFF, 0xFF},
-			msgLimit:       math.MaxInt32,
-			expectedErr:    nil,
-			expectedMsgLen: math.MaxInt32,
-		},
-		{
-			msgLenBytes:    []byte{0b10000000, 0x00, 0x00, 0x01},
-			msgLimit:       math.MaxInt32,
+			msgLenBytes:    []byte{0xFF, 0xFF, 0xFF, 0xFF},
+			msgLimit:       math.MaxUint32,
 			expectedErr:    nil,
-			expectedMsgLen: 1,
+			expectedMsgLen: math.MaxUint32,
 		},
 		{
-			msgLenBytes:    []byte{0b10000000, 0x00, 0x00, 0x01},
-			msgLimit:       1,
+			msgLenBytes:    []byte{0x00, 0x00, 0x00, 0x01},
+			msgLimit:       10,
 			expectedErr:    nil,
 			expectedMsgLen: 1,
 		},
@@ -126,34 +99,3 @@ func TestReadMsgLen(t *testing.T) {
 		require.Equal(tv.expectedMsgLen, msgLenAfterWrite)
 	}
 }
-
-func TestBackwardsCompatibleReadMsgLen(t *testing.T) {
-	require := require.New(t)
-
-	tt := []struct {
-		msgLenBytes    []byte
-		msgLimit       uint32
-		expectedMsgLen uint32
-	}{
-		{
-			msgLenBytes:    []byte{0b01111111, 0xFF, 0xFF, 0xFF},
-			msgLimit:       math.MaxInt32,
-			expectedMsgLen: math.MaxInt32,
-		},
-		{
-			msgLenBytes:    []byte{0b00000000, 0x00, 0x00, 0x01},
-			msgLimit:       math.MaxInt32,
-			expectedMsgLen: 1,
-		},
-		{
-			msgLenBytes:    []byte{0b00000000, 0x00, 0x00, 0x01},
-			msgLimit:       1,
-			expectedMsgLen: 1,
-		},
-	}
-	for _, tv := range tt {
-		msgLen, err := readMsgLen(tv.msgLenBytes, tv.msgLimit)
-		require.NoError(err)
-		require.Equal(tv.expectedMsgLen, msgLen)
-	}
-}