public override async ValueTask <BucketBytes> ReadAsync(int requested = int.MaxValue)
{
switch (_state)
{
case DechunkState.Chunk:
{
var bb = await Inner.ReadAsync(Math.Min(requested, _chunkLeft)).ConfigureAwait(false);
_chunkLeft -= bb.Length;
if (_chunkLeft == 0)
{
_state = DechunkState.Term;
_chunkLeft = 2; // CRLF
}
return(bb);
}
case DechunkState.Eof:
return(BucketBytes.Eof);
default:
await Advance(true).ConfigureAwait(false);
if (_state == DechunkState.Chunk)
{
goto case DechunkState.Chunk;
}
else if (_state == DechunkState.Eof)
{
goto case DechunkState.Eof;
}
else
{
throw new InvalidOperationException();
}
}
}
async ValueTask Advance(bool wait)
{
while (_state != DechunkState.Chunk && _state != DechunkState.Eof)
{
if (!wait)
{
var bb = Inner.Peek();
if (bb.IsEmpty)
{
return;
}
}
switch (_state)
{
case DechunkState.Start:
{
var(bb, eol) = await Inner.ReadUntilEolAsync(BucketEol.CRLF | BucketEol.LF).ConfigureAwait(false);
if (eol == BucketEol.CRLF || eol == BucketEol.LF)
{
if (bb.Length > eol.CharCount())
{
_chunkLeft = Convert.ToInt32(bb.ToASCIIString(eol), 16);
}
else
{
_chunkLeft = 0;
}
_state = _chunkLeft > 0 ? DechunkState.Chunk : (_noFin ? DechunkState.Eof : DechunkState.Fin);
}
else if (bb.IsEof)
{
throw new HttpBucketException($"Unexpected EOF in {Name} Bucket");
}
else
{
_state = DechunkState.Size;
_start = bb.ToArray();
if (_start.Length > 16 || _start.Any(x => !IsHexCharOrCR(x)))
{
throw new HttpBucketException($"Invalid chunk header in {Name} Bucket");
}
}
}
break;
case DechunkState.Size:
{
var(bb, eol) = await Inner.ReadUntilEolAsync(BucketEol.CRLF | BucketEol.LF).ConfigureAwait(false);
if (eol != BucketEol.None && eol != BucketEol.CRSplit)
{
bb = _start !.AppendBytes(bb);
// Strip final '\r' if any, before passing to ToInt32
_chunkLeft = Convert.ToInt32(bb.Trim(eol).ToASCIIString(), 16);
_state = _chunkLeft > 0 ? DechunkState.Chunk : (_noFin ? DechunkState.Eof : DechunkState.Fin);
}
else if (bb.IsEof)
{
throw new HttpBucketException($"Unexpected EOF in {Name} Bucket");
}
else
{
_start = _start !.AppendBytes(bb);
if (_start.Length > 16 || _start.Any(x => !IsHexCharOrCR(x)))
{
throw new HttpBucketException($"Invalid chunk header in {Name} Bucket");
}
}
}
break;
case DechunkState.Term:
{
var bb = await Inner.ReadAsync(_chunkLeft).ConfigureAwait(false);
_chunkLeft -= bb.Length;
if (bb.IsEof)
{
throw new HttpBucketException($"Unexpected EOF in {Name} Bucket");
}
if (_chunkLeft == 0)
{
_state = DechunkState.Start;
}
}
break;
case DechunkState.Fin:
{
var bb = await Inner.ReadAsync(2).ConfigureAwait(false);
if (bb.Length == 2)
{
_state = DechunkState.Eof;
}
else if (bb.Length == 1)
{
_state = DechunkState.Fin2;
}
else
{
throw new HttpBucketException($"Unexpected EOF in {Name} Bucket");
}
}
break;
case DechunkState.Fin2:
{
var bb = await Inner.ReadAsync(1).ConfigureAwait(false);
if (bb.Length == 1)
{
_state = DechunkState.Eof;
}
else
{
throw new HttpBucketException($"Unexpected EOF in {Name} Bucket");
}
}
break;
case DechunkState.Chunk:
case DechunkState.Eof:
return;
}
}
}
