private static async Task <string?> PipeReadLine(this PipeReader reader, Encoding encoding)
{
byte[] testChars = new byte[] { (byte)'\n', (byte)'\r' };
while (true)
{
ReadResult result = await reader.ReadAsync().ConfigureAwait(false);
ReadOnlySequence <byte> buffer = result.Buffer;
SequencePosition? position = buffer.PositionOfAny(testChars);
if (position is null)
{
if (result.IsCompleted)
{
if (buffer.Length == 0)
{
return(null);
}
string rtn = encoding.GetString(buffer.ToArray());
reader.AdvanceTo(buffer.End);
return(rtn);
}
reader.AdvanceTo(buffer.Start, buffer.End);
}
else
{
ReadOnlySequence <byte> line = buffer.Slice(0, position.Value);
string linestring = encoding.GetString(line.ToArray());
reader.AdvanceTo(line.End);
while (true)
{
result = await reader.ReadAsync().ConfigureAwait(false);
buffer = result.Buffer;
if (buffer.Length == 1)
{
// if the size is 1 and its completed just advance to end
if (result.IsCompleted)
{
reader.AdvanceTo(buffer.End);
break;
}
// if the size is 1 and there is more signal that we need more so we can read \r\n
reader.AdvanceTo(buffer.Start, buffer.GetPosition(1));
}
else if (buffer.Length > 1)
{
char c = (char)buffer.GetAt(0);
long advances = 0;
// \n - UNIX \r\n - DOS \r - Mac
switch (c)
{
// if its a \r advance one position and check if next char is a \n
case '\r':
advances++;
if (buffer.GetAt(1) == '\n')
{
advances++;
}
break;
// if its a \n just advance one position
case '\n':
advances++;
break;
}
reader.AdvanceTo(buffer.GetPosition(advances));
break;
}
else if (result.IsCompleted)
{
reader.AdvanceTo(buffer.End);
break;
}
}
return(linestring);
}
}
}