namespace System.Text { internal struct DecoderFallbackBufferHelper { internal unsafe byte* byteStart; internal unsafe char* charEnd; private readonly DecoderFallbackBuffer _fallbackBuffer; public unsafe DecoderFallbackBufferHelper(DecoderFallbackBuffer fallbackBuffer) { _fallbackBuffer = fallbackBuffer; byteStart = null; charEnd = null; } internal unsafe void InternalReset() { byteStart = null; _fallbackBuffer.Reset(); } internal unsafe void InternalInitialize(byte* _byteStart, char* _charEnd) { byteStart = _byteStart; charEnd = _charEnd; } internal unsafe bool InternalFallback(byte[] bytes, byte* pBytes, ref char* chars) { if (_fallbackBuffer.Fallback(bytes, (int)(pBytes - byteStart - bytes.Length))) { char* ptr = chars; bool flag = false; char nextChar; while ((nextChar = _fallbackBuffer.GetNextChar()) != 0) { if (char.IsSurrogate(nextChar)) { if (char.IsHighSurrogate(nextChar)) { if (flag) throw new ArgumentException(System.SR.Argument_InvalidCharSequenceNoIndex); flag = true; } else { if (!flag) throw new ArgumentException(System.SR.Argument_InvalidCharSequenceNoIndex); flag = false; } } if (ptr >= charEnd) return false; char* intPtr = ptr; ptr = intPtr + 1; *intPtr = nextChar; } if (flag) throw new ArgumentException(System.SR.Argument_InvalidCharSequenceNoIndex); chars = ptr; } return true; } internal unsafe int InternalFallback(byte[] bytes, byte* pBytes) { if (_fallbackBuffer.Fallback(bytes, (int)(pBytes - byteStart - bytes.Length))) { int num = 0; bool flag = false; char nextChar; while ((nextChar = _fallbackBuffer.GetNextChar()) != 0) { if (char.IsSurrogate(nextChar)) { if (char.IsHighSurrogate(nextChar)) { if (flag) throw new ArgumentException(System.SR.Argument_InvalidCharSequenceNoIndex); flag = true; } else { if (!flag) throw new ArgumentException(System.SR.Argument_InvalidCharSequenceNoIndex); flag = false; } } num++; } if (flag) throw new ArgumentException(System.SR.Argument_InvalidCharSequenceNoIndex); return num; } return 0; } } }