public static async ValueTask <(BucketBytes, BucketEol)> ReadUntilEolFullAsync(this Bucket bucket, BucketEol acceptableEols, BucketEolState?eolState = null, int requested = int.MaxValue)
{
if (bucket is null)
{
throw new ArgumentNullException(nameof(bucket));
}
ByteCollector result = new();
int rq = requested;
if (eolState?._kept.HasValue ?? false)
{
var kept = eolState._kept !.Value;
eolState._kept = null;
switch (kept)
{
case (byte)'\n' when(0 != (acceptableEols & BucketEol.LF)):
return(new BucketBytes(new[] { kept }, 0, 1), BucketEol.LF);
case (byte)'\r' when(0 != (acceptableEols & BucketEol.CR) && (acceptableEols & BucketEol.CRLF) == 0):
return(new BucketBytes(new[] { kept }, 0, 1), BucketEol.CR);
case (byte)'\0' when(0 != (acceptableEols & BucketEol.Zero)):
return(new BucketBytes(new[] { kept }, 0, 1), BucketEol.Zero);
case (byte)'\r' when(0 != (acceptableEols & BucketEol.CRLF)):
rq = 1;
goto default;
default:
result.Append(kept);
break;
}
}
else if ((BucketEol.CRLF | BucketEol.CR) == (acceptableEols & (BucketEol.CRLF | BucketEol.CR)) && eolState is null)
{
throw new ArgumentNullException(nameof(eolState));
}
while (true)
{
BucketBytes bb;
BucketEol eol;
(bb, eol) = await bucket.ReadUntilEolAsync(acceptableEols, rq).ConfigureAwait(false);
if (eol != BucketEol.None && eol != BucketEol.CRSplit && result.IsEmpty)
{
return(bb, eol);
}
else if (bb.IsEmpty)
{
if (bb.IsEof)
{
return(result.ToResultOrEof(), eol);
}
else
{
throw new InvalidOperationException();
}
}
else if (rq == 1 && (acceptableEols & BucketEol.CRLF) != 0 && result.SequenceEqual(new[] { (byte)'\r' }))
{
if (bb[0] == '\n')
{
return(result.AsBytes(bb), BucketEol.CRLF);
}
else if ((acceptableEols & BucketEol.CR) != 0)
{
eolState !._kept = bb[0];
return(new[] { (byte)'\r' }, BucketEol.CR);
}
else if (eol != BucketEol.None)
{
return(result.AsBytes(bb), eol); // '\0' case
}
}
rq = (requested -= bb.Length);
if (requested == 0)
{
return(result.AsBytes(bb), eol);
}
result.Append(bb);
if (eol == BucketEol.CRSplit)
{
// Bad case. We may have a \r that might be a \n
var poll = await bucket.PollReadAsync(1).ConfigureAwait(false);
if (!poll.Data.IsEmpty)
{
var b = poll[0];
bb = await poll.ReadAsync(1).ConfigureAwait(false);
if (b == '\n')
{
// Phew, we were lucky. We got a \r\n
return(result.AsBytes(bb), BucketEol.CRLF);
}
else if (0 != (acceptableEols & BucketEol.CR))
{
// We return the part ending with '\r'
eolState !._kept = b; // And keep the next byte
return(result.AsBytes(), BucketEol.CR);
}
else if (b == '\0' && 0 != (acceptableEols & BucketEol.Zero))
{
// Another edge case :(
return(result.AsBytes(bb), BucketEol.Zero);
}
else
{
result.Append(b);
continue;
}
}
else
{
// We are at eof, so no issues with future reads
eol = (0 != (acceptableEols & BucketEol.CR) ? BucketEol.CR : BucketEol.None);
return(result.AsBytes(), eol);
}
}
else if (eol == BucketEol.None)
{
continue;
}
else
{
return(result.AsBytes(), eol);
}
}
}