internal async Task <bool> Parse(Uri serverAddress, Stream request, NHError error)
{
bool needsInput;
try
{
// the following parsing methods return false if they read the stream, but didn't like the request,
// in which case they keep reading to the end. If there is a parsing error that means the stream is
// now unsynchronized, they throw an exception
MemoryStream headerStream = await FetchHeaders(request);
if (headerStream == null || headerStream.Length == 0)
{
closedTask.SetResult(false);
return(false);
}
using (StreamReader reader = new StreamReader(headerStream, Encoding.UTF8, false, 1024, true))
{
needsInput = ParsePreamble(serverAddress, reader, error);
ParseHeaders(reader, error);
}
if (needsInput)
{
needsInput = await MaybeContinue(request, error);
}
}
catch (Exception e)
{
closedTask.SetResult(false);
throw e;
}
if (needsInput)
{
if (headers[HttpRequestHeader.TransferEncoding] == "chunked")
{
length = -1;
currentChunkRemaining = -1;
}
else
{
length = long.Parse(headers[HttpRequestHeader.ContentLength]);
currentChunkRemaining = length;
}
socketStream = request;
}
else
{
length = 0;
currentChunkRemaining = 0;
closedTask.SetResult(true);
}
return(true);
}
private void AddHeader(string headerLine, NHError error)
{
int colonPos = headerLine.IndexOf(':');
if (colonPos == -1)
{
throw new ApplicationException("Bad header field " + headerLine);
}
string key = headerLine.Substring(0, colonPos).Trim();
string value = headerLine.Substring(colonPos + 1).Trim();
try
{
headers.Add(key, value);
}
catch (Exception e)
{
logger.Log("Parsing header line " + headerLine + " got exception " + e.ToString());
throw new ApplicationException("Bad header field " + headerLine + " threw exception", e);
}
}
private void ParseHeaders(StreamReader reader, NHError error)
{
string currentHeader = null;
while (true)
{
string headerLine = reader.ReadLine();
if (headerLine.Length == 0)
{
if (currentHeader == null)
{
throw new ApplicationException("No headers");
}
AddHeader(currentHeader, error);
return;
}
if (headerLine.StartsWith(" ") || headerLine.StartsWith("\t"))
{
if (currentHeader == null)
{
throw new ApplicationException("Continuation header without preceding header");
}
currentHeader = currentHeader + headerLine;
}
else
{
if (currentHeader != null)
{
AddHeader(currentHeader, error);
}
currentHeader = headerLine;
}
}
}
protected abstract Task <bool> MaybeContinue(Stream request, NHError error);
protected abstract bool ParsePreamble(Uri serverAddress, StreamReader stream, NHError error);
