System.Text.EncoderFallbackBuffer.InternalInitialize C# (CSharp) Method

        internal unsafe void InternalInitialize(char* charStart, char* charEnd, EncoderNLS encoder, bool setEncoder)
        {
            this.charStart = charStart;
            this.charEnd = charEnd;
            this.encoder = encoder;
            this.setEncoder = setEncoder;
            this.bUsedEncoder = false;
            this.bFallingBack = false;
            this.iRecursionCount = 0;
        }

        internal override unsafe int GetByteCount(char *chars, int count, EncoderNLS encoder)
        {
            char ch2;

            base.CheckMemorySection();
            char charLeftOver = '\0';

            if (encoder != null)
            {
                charLeftOver = encoder.charLeftOver;
                if (encoder.InternalHasFallbackBuffer && (encoder.FallbackBuffer.Remaining > 0))
                {
                    throw new ArgumentException(Environment.GetResourceString("Argument_EncoderFallbackNotEmpty", new object[] { this.EncodingName, encoder.Fallback.GetType() }));
                }
            }
            int   num     = 0;
            char *charEnd = chars + count;
            EncoderFallbackBuffer fallbackBuffer = null;

            if (charLeftOver > '\0')
            {
                fallbackBuffer = encoder.FallbackBuffer;
                fallbackBuffer.InternalInitialize(chars, charEnd, encoder, false);
                fallbackBuffer.InternalFallback(charLeftOver, ref chars);
            }
            while (((ch2 = (fallbackBuffer == null) ? '\0' : fallbackBuffer.InternalGetNextChar()) != '\0') || (chars < charEnd))
            {
                if (ch2 == '\0')
                {
                    ch2 = chars[0];
                    chars++;
                }
                ushort num2 = this.mapUnicodeToBytes[ch2];
                if ((num2 == 0) && (ch2 != '\0'))
                {
                    if (fallbackBuffer == null)
                    {
                        if (encoder == null)
                        {
                            fallbackBuffer = base.encoderFallback.CreateFallbackBuffer();
                        }
                        else
                        {
                            fallbackBuffer = encoder.FallbackBuffer;
                        }
                        fallbackBuffer.InternalInitialize(charEnd - count, charEnd, encoder, false);
                    }
                    fallbackBuffer.InternalFallback(ch2, ref chars);
                }
                else
                {
                    num++;
                    if (num2 >= 0x100)
                    {
                        num++;
                    }
                }
            }
            return(num);
        }