namespace System.Text { internal sealed class EncodingByteBuffer { private unsafe byte* _bytes; private unsafe readonly byte* _byteStart; private unsafe readonly byte* _byteEnd; private unsafe char* _chars; private unsafe readonly char* _charStart; private unsafe readonly char* _charEnd; private int _byteCountResult; private readonly EncodingNLS _enc; private readonly System.Text.EncoderNLS _encoder; internal EncoderFallbackBuffer fallbackBuffer; internal EncoderFallbackBufferHelper fallbackBufferHelper; internal unsafe bool MoreData { get { if (fallbackBuffer.Remaining <= 0) return _chars < _charEnd; return true; } } internal unsafe int CharsUsed => (int)(_chars - _charStart); internal int Count => _byteCountResult; internal unsafe EncodingByteBuffer(EncodingNLS inEncoding, System.Text.EncoderNLS inEncoder, byte* inByteStart, int inByteCount, char* inCharStart, int inCharCount) { _enc = inEncoding; _encoder = inEncoder; _charStart = inCharStart; _chars = inCharStart; _charEnd = inCharStart + inCharCount; _bytes = inByteStart; _byteStart = inByteStart; _byteEnd = inByteStart + inByteCount; if (_encoder == null) fallbackBuffer = _enc.EncoderFallback.CreateFallbackBuffer(); else { fallbackBuffer = _encoder.FallbackBuffer; if (_encoder.m_throwOnOverflow && _encoder.InternalHasFallbackBuffer && fallbackBuffer.Remaining > 0) throw new ArgumentException(System.SR.Format(System.SR.Argument_EncoderFallbackNotEmpty, _encoder.Encoding.EncodingName, _encoder.Fallback.GetType())); } fallbackBufferHelper = new EncoderFallbackBufferHelper(fallbackBuffer); fallbackBufferHelper.InternalInitialize(_chars, _charEnd, _encoder, _bytes != null); } internal unsafe bool AddByte(byte b, int moreBytesExpected) { if (_bytes != null) { if (_bytes >= _byteEnd - moreBytesExpected) { MovePrevious(true); return false; } *(_bytes++) = b; } _byteCountResult++; return true; } internal bool AddByte(byte b1) { return AddByte(b1, 0); } internal bool AddByte(byte b1, byte b2) { return AddByte(b1, b2, 0); } internal bool AddByte(byte b1, byte b2, int moreBytesExpected) { if (AddByte(b1, 1 + moreBytesExpected)) return AddByte(b2, moreBytesExpected); return false; } internal bool AddByte(byte b1, byte b2, byte b3) { return AddByte(b1, b2, b3, 0); } internal bool AddByte(byte b1, byte b2, byte b3, int moreBytesExpected) { if (AddByte(b1, 2 + moreBytesExpected) && AddByte(b2, 1 + moreBytesExpected)) return AddByte(b3, moreBytesExpected); return false; } internal bool AddByte(byte b1, byte b2, byte b3, byte b4) { if (AddByte(b1, 3) && AddByte(b2, 2) && AddByte(b3, 1)) return AddByte(b4, 0); return false; } internal unsafe void MovePrevious(bool bThrow) { if (fallbackBufferHelper.bFallingBack) fallbackBuffer.MovePrevious(); else if (_chars > _charStart) { _chars--; } if (bThrow) _enc.ThrowBytesOverflow(_encoder, _bytes == _byteStart); } internal unsafe bool Fallback(char charFallback) { return fallbackBufferHelper.InternalFallback(charFallback, ref _chars); } internal unsafe char GetNextChar() { char c = fallbackBufferHelper.InternalGetNextChar(); if (c == '' && _chars < _charEnd) { char* chars = _chars; _chars = chars + 1; c = *chars; } return c; } } }