ReadAsyncInternal()

override async ValueTask< int > System.IO.StreamReader.ReadAsyncInternal ( Memory< char > buffer, CancellationToken cancellationToken )

inlinepackagevirtualinherited

Reimplemented from System.IO.TextReader.

Definition at line 841 of file StreamReader.cs.

    {
        bool flag = _charPos == _charLen;
        bool flag2 = flag;
        if (flag2)
        {
            flag2 = await ReadBufferAsync(cancellationToken).ConfigureAwait(continueOnCapturedContext: false) == 0;
        }
        if (flag2)
        {
            return 0;
        }
        int charsRead = 0;
        bool readToUserBuffer = false;
        byte[] tmpByteBuffer = _byteBuffer;
        Stream tmpStream = _stream;
        int count = buffer.Length;
        while (count > 0)
        {
            int i = _charLen - _charPos;
            if (i == 0)
            {
                _charLen = 0;
                _charPos = 0;
                if (!_checkPreamble)
                {
                    _byteLen = 0;
                }
                readToUserBuffer = count >= _maxCharsPerBuffer;
                do
                {
                    if (_checkPreamble)
                    {
                        int bytePos = _bytePos;
                        int num = await tmpStream.ReadAsync(new Memory<byte>(tmpByteBuffer, bytePos, tmpByteBuffer.Length - bytePos), cancellationToken).ConfigureAwait(continueOnCapturedContext: false);
                        if (num == 0)
                        {
                            if (_byteLen > 0)
                            {
                                if (readToUserBuffer)
                                {
                                    i = _decoder.GetChars(new ReadOnlySpan<byte>(tmpByteBuffer, 0, _byteLen), buffer.Span.Slice(charsRead), flush: false);
                                    _charLen = 0;
                                }
                                else
                                {
                                    i = _decoder.GetChars(tmpByteBuffer, 0, _byteLen, _charBuffer, 0);
                                    _charLen += i;
                                }
                            }
                            _isBlocked = true;
                            break;
                        }
                        _byteLen += num;
                    }
                    else
                    {
                        _byteLen = await tmpStream.ReadAsync(new Memory<byte>(tmpByteBuffer), cancellationToken).ConfigureAwait(continueOnCapturedContext: false);
                        if (_byteLen == 0)
                        {
                            _isBlocked = true;
                            break;
                        }
                    }
                    _isBlocked = _byteLen < tmpByteBuffer.Length;
                    if (!IsPreamble())
                    {
                        if (_detectEncoding && _byteLen >= 2)
                        {
                            DetectEncoding();
                            readToUserBuffer = count >= _maxCharsPerBuffer;
                        }
                        _charPos = 0;
                        if (readToUserBuffer)
                        {
                            i += _decoder.GetChars(new ReadOnlySpan<byte>(tmpByteBuffer, 0, _byteLen), buffer.Span.Slice(charsRead), flush: false);
                            _charLen = 0;
                        }
                        else
                        {
                            i = _decoder.GetChars(tmpByteBuffer, 0, _byteLen, _charBuffer, 0);
                            _charLen += i;
                        }
                    }
                }
                while (i == 0);
                if (i == 0)
                {
                    break;
                }
            }
            if (i > count)
            {
                i = count;
            }
            if (!readToUserBuffer)
            {
                new Span<char>(_charBuffer, _charPos, i).CopyTo(buffer.Span.Slice(charsRead));
                _charPos += i;
            }
            charsRead += i;
            count -= i;
            if (_isBlocked)
            {
                break;
            }
        }
        return charsRead;
    }

References System.IO.StreamReader._byteBuffer, System.IO.StreamReader._byteLen, System.IO.StreamReader._bytePos, System.IO.StreamReader._charBuffer, System.IO.StreamReader._charLen, System.IO.StreamReader._charPos, System.IO.StreamReader._checkPreamble, System.IO.StreamReader._decoder, System.IO.StreamReader._detectEncoding, System.IO.StreamReader._isBlocked, System.IO.StreamReader._maxCharsPerBuffer, System.IO.StreamReader._stream, System.buffer, System.cancellationToken, System.Threading.Tasks.ValueTask< TResult >.ConfigureAwait(), System.Span< T >.CopyTo(), System.count, System.IO.StreamReader.DetectEncoding(), System.Text.Decoder.GetChars(), System.IO.StreamReader.IsPreamble(), System.IO.Stream.Length, System.IO.Stream.ReadAsync(), System.IO.StreamReader.ReadBufferAsync(), and System.ReadOnlySpan< T >.Slice().

Referenced by System.IO.StreamReader.ReadAsync(), and System.IO.StreamReader.ReadAsync().