private static void AppendStringInternal(this IWriter writer, string value, int startIndex, int endIndex)
{
for (var i = startIndex; i <= endIndex;)
{
UnicodeCodePoint codePoint;
int encodedChars;
var success = Utf16LittleEndianEncoder.TryDecodeCodePointFromString(value, i, out codePoint, out encodedChars);
if (!success)
{
throw new ArgumentException();
}
i += encodedChars;
int encodedBytes;
success = Utf8Encoder.TryEncodeCodePoint(
codePoint,
writer.GetFreeBuffer(MaxUtf8CodePointBytes).ToSpan(),
out encodedBytes);
Debug.Assert(success);
writer.CommitBytes(encodedBytes);
}
}
// TODO: This should return Utf16CodeUnits which should wrap byte[]/Span<byte>, same for other encoders
private static byte[] GetUtf8BytesFromString(string s)
{
int len = 0;
for (int i = 0; i < s.Length; /* intentionally no increment */)
{
UnicodeCodePoint codePoint;
int encodedChars;
if (!Utf16LittleEndianEncoder.TryDecodeCodePointFromString(s, i, out codePoint, out encodedChars))
{
throw new ArgumentException("s", "Invalid surrogate pair in the string.");
}
if (encodedChars <= 0)
{
// TODO: Fix exception type
throw new Exception("internal error");
}
int encodedBytes = Utf8Encoder.GetNumberOfEncodedBytes(codePoint);
if (encodedBytes == 0)
{
// TODO: Fix exception type
throw new Exception("Internal error: Utf16Decoder somehow got CodePoint out of range");
}
len += encodedBytes;
i += encodedChars;
}
byte[] bytes = new byte[len];
unsafe
{
fixed(byte *array_pinned = bytes)
{
Span <byte> p = new Span <byte>(array_pinned, len);
for (int i = 0; i < s.Length; /* intentionally no increment */)
{
UnicodeCodePoint codePoint;
int encodedChars;
if (Utf16LittleEndianEncoder.TryDecodeCodePointFromString(s, i, out codePoint, out encodedChars))
{
i += encodedChars;
int encodedBytes;
if (Utf8Encoder.TryEncodeCodePoint(codePoint, p, out encodedBytes))
{
p = p.Slice(encodedBytes);
}
else
{
// TODO: Fix exception type
throw new Exception("Internal error: Utf16Decoder somehow got CodePoint out of range or the buffer is too small");
}
}
else
{
// TODO: Fix exception type
throw new Exception("Internal error: we did pre-validation of the string, nothing should go wrong");
}
}
}
}
return(bytes);
}
