GetByteCount() [2/7]

unsafe override int System.Text.UTF32Encoding.GetByteCount ( char * chars, int count, EncoderNLS encoder )

inlinepackagevirtual

Reimplemented from System.Text.Encoding.

Definition at line 330 of file UTF32Encoding.cs.

    {
        char* ptr = chars + count;
        char* charStart = chars;
        int num = 0;
        char c = '\0';
        EncoderFallbackBuffer encoderFallbackBuffer = null;
        if (encoder != null)
        {
            c = encoder._charLeftOver;
            encoderFallbackBuffer = encoder.FallbackBuffer;
            if (encoderFallbackBuffer.Remaining > 0)
            {
                throw new ArgumentException(SR.Format(SR.Argument_EncoderFallbackNotEmpty, EncodingName, encoder.Fallback?.GetType().ToString() ?? string.Empty));
            }
        }
        else
        {
            encoderFallbackBuffer = encoderFallback.CreateFallbackBuffer();
        }
        encoderFallbackBuffer.InternalInitialize(charStart, ptr, encoder, setEncoder: false);
        while (true)
        {
            char c2;
            if ((c2 = encoderFallbackBuffer.InternalGetNextChar()) != 0 || chars < ptr)
            {
                if (c2 == '\0')
                {
                    c2 = *chars;
                    chars++;
                }
                if (c != 0)
                {
                    if (char.IsLowSurrogate(c2))
                    {
                        c = '\0';
                        num += 4;
                        continue;
                    }
                    chars--;
                    char* chars2 = chars;
                    encoderFallbackBuffer.InternalFallback(c, ref chars2);
                    chars = chars2;
                    c = '\0';
                }
                else if (char.IsHighSurrogate(c2))
                {
                    c = c2;
                }
                else if (char.IsLowSurrogate(c2))
                {
                    char* chars2 = chars;
                    encoderFallbackBuffer.InternalFallback(c2, ref chars2);
                    chars = chars2;
                }
                else
                {
                    num += 4;
                }
            }
            else
            {
                if ((encoder != null && !encoder.MustFlush) || c <= '\0')
                {
                    break;
                }
                char* chars2 = chars;
                encoderFallbackBuffer.InternalFallback(c, ref chars2);
                chars = chars2;
                c = '\0';
            }
        }
        if (num < 0)
        {
            throw new ArgumentOutOfRangeException("count", SR.ArgumentOutOfRange_GetByteCountOverflow);
        }
        return num;
    }

References System.Text.EncoderNLS._charLeftOver, System.SR.Argument_EncoderFallbackNotEmpty, System.SR.ArgumentOutOfRange_GetByteCountOverflow, System.chars, System.count, System.Text.EncoderFallback.CreateFallbackBuffer(), System.Text.Encoding.encoderFallback, System.Text.Encoding.EncodingName, System.Text.EncoderNLS.Fallback, System.Text.EncoderNLS.FallbackBuffer, System.SR.Format(), System.Text.EncoderFallbackBuffer.InternalFallback(), System.Text.EncoderFallbackBuffer.InternalGetNextChar(), System.Text.EncoderFallbackBuffer.InternalInitialize(), System.Text.EncoderNLS.MustFlush, and System.Text.EncoderFallbackBuffer.Remaining.