TryValidateUtf8()

static bool System.Net.WebSockets.ManagedWebSocket.TryValidateUtf8 ( Span< byte > span, bool endOfMessage, Utf8MessageState state )

inlinestaticprivate

Definition at line 1465 of file ManagedWebSocket.cs.

    {
        int num = 0;
        while (num < span.Length)
        {
            if (!state.SequenceInProgress)
            {
                state.SequenceInProgress = true;
                byte b = span[num];
                num++;
                if ((b & 0x80) == 0)
                {
                    state.AdditionalBytesExpected = 0;
                    state.CurrentDecodeBits = b & 0x7F;
                    state.ExpectedValueMin = 0;
                }
                else
                {
                    if ((b & 0xC0) == 128)
                    {
                        return false;
                    }
                    if ((b & 0xE0) == 192)
                    {
                        state.AdditionalBytesExpected = 1;
                        state.CurrentDecodeBits = b & 0x1F;
                        state.ExpectedValueMin = 128;
                    }
                    else if ((b & 0xF0) == 224)
                    {
                        state.AdditionalBytesExpected = 2;
                        state.CurrentDecodeBits = b & 0xF;
                        state.ExpectedValueMin = 2048;
                    }
                    else
                    {
                        if ((b & 0xF8) != 240)
                        {
                            return false;
                        }
                        state.AdditionalBytesExpected = 3;
                        state.CurrentDecodeBits = b & 7;
                        state.ExpectedValueMin = 65536;
                    }
                }
            }
            while (state.AdditionalBytesExpected > 0 && num < span.Length)
            {
                byte b2 = span[num];
                if ((b2 & 0xC0) != 128)
                {
                    return false;
                }
                num++;
                state.AdditionalBytesExpected--;
                state.CurrentDecodeBits = (state.CurrentDecodeBits << 6) | (b2 & 0x3F);
                if (state.AdditionalBytesExpected == 1 && state.CurrentDecodeBits >= 864 && state.CurrentDecodeBits <= 895)
                {
                    return false;
                }
                if (state.AdditionalBytesExpected == 2 && state.CurrentDecodeBits >= 272)
                {
                    return false;
                }
            }
            if (state.AdditionalBytesExpected == 0)
            {
                state.SequenceInProgress = false;
                if (state.CurrentDecodeBits < state.ExpectedValueMin)
                {
                    return false;
                }
            }
        }
        if (endOfMessage && state.SequenceInProgress)
        {
            return false;
        }
        return true;
    }

References System.Span< T >.Length, and System.state.

Referenced by System.Net.WebSockets.ManagedWebSocket._003CReceiveAsyncPrivate_003Ed__63< TResult >.MoveNext().