bool ParseBody(MultipartMimeParsingContex context)
{
bool result = this.FindBoundary(context);
if (result)
{
byte[] body = new byte[context.ParsingIndex];
Buffer.BlockCopy(this.buffer, this.offset, body, 0, context.ParsingIndex);
context.Message.Body = new MemoryStream(body);
this.ConsumeBytes(context.ParsingIndex + context.Boundary.Length);
context.ParsingIndex = 0;
context.State = ParsingState.AfterBoundary;
}
return(result);
}
void ParseMultipartMime(int read, MultipartMimeParsingContex context)
{
this.count += read;
bool continueParsing = true;
while (continueParsing)
{
switch (context.State)
{
case ParsingState.FirstBoundary:
continueParsing = this.ParseFirstMimeBoundary(context);
break;
case ParsingState.ContentTypeHeader:
continueParsing = this.ParseContentTypeHeader(context);
break;
case ParsingState.ContentDescriptionHeader:
continueParsing = this.ParseContentDescriptionHeader(context);
break;
case ParsingState.CRLF:
continueParsing = this.ParseCRLF(context);
break;
case ParsingState.Body:
continueParsing = this.ParseBody(context);
if (continueParsing)
{
this.DispatchMessage(context.Message);
context.Message = null;
}
break;
case ParsingState.AfterBoundary:
continueParsing = this.ParseAfterBoundary(context);
break;
case ParsingState.Epilogue:
// ignore all data after the final MIME boundary
continueParsing = false;
this.ConsumeBytes(this.count);
break;
}
;
}
}
bool ParseCRLF(MultipartMimeParsingContex context)
{
bool result = this.FindCRLF(context);
if (result)
{
if (context.ParsingIndex != 0)
{
throw new InvalidOperationException("Malformed HTTP long poll response. Unexpected MIME part header.");
}
this.ConsumeBytes(2);
context.ParsingIndex = 0;
context.State = ParsingState.Body;
}
return(result);
}
bool FindCRLF(MultipartMimeParsingContex context)
{
bool result = false;
while (!result && context.ParsingIndex < (this.count - 1))
{
if (this.buffer[this.offset + context.ParsingIndex] == 0x0D &&
this.buffer[this.offset + context.ParsingIndex + 1] == 0x0A)
{
result = true;
}
else
{
context.ParsingIndex++;
}
}
return(result);
}
bool FindBoundary(MultipartMimeParsingContex context)
{
bool result = false;
while (!result && context.ParsingIndex <= (this.count - context.Boundary.Length))
{
result = true;
int i = 0;
while (result && i < context.Boundary.Length)
{
result = this.buffer[this.offset + context.ParsingIndex + i] == context.Boundary[i];
i++;
}
if (!result)
{
context.ParsingIndex++;
}
}
return(result);
}
bool ParseContentDescriptionHeader(MultipartMimeParsingContex context)
{
bool result = this.FindCRLF(context);
if (result)
{
string header = Encoding.UTF8.GetString(this.buffer, this.offset, context.ParsingIndex);
Match m = contentDescriptionRegex.Match(header);
if (!m.Success)
{
throw new InvalidOperationException("Malformed HTTP long poll response. Connot determine topicId and messageId of the MIME part.");
}
context.Message.TopicId = int.Parse(m.Groups[1].Value, CultureInfo.InvariantCulture);
context.Message.MessageId = int.Parse(m.Groups[2].Value, CultureInfo.InvariantCulture);
this.ConsumeBytes(context.ParsingIndex + 2);
context.ParsingIndex = 0;
context.State = ParsingState.CRLF;
}
return(result);
}
bool ParseContentTypeHeader(MultipartMimeParsingContex context)
{
bool result = this.FindCRLF(context);
if (result)
{
string header = Encoding.UTF8.GetString(this.buffer, this.offset, context.ParsingIndex);
Match m = contentTypeRegex.Match(header);
if (!m.Success)
{
throw new InvalidOperationException("Malformed HTTP long poll response. Cannot determine the content type of the MIME part.");
}
context.Message = new PubsubMessage();
context.Message.ContentType = m.Groups[1].Value;
this.ConsumeBytes(context.ParsingIndex + 2);
context.ParsingIndex = 0;
context.State = ParsingState.ContentDescriptionHeader;
}
return(result);
}
bool ParseFirstMimeBoundary(MultipartMimeParsingContex context)
{
bool result = this.FindCRLF(context);
if (result)
{
if (context.ParsingIndex < 3 || this.buffer[this.offset] != 0x2D || this.buffer[this.offset + 1] != 0x2D)
{
// boundary does not start with "--" or is shorter than 1 character
throw new InvalidOperationException("Malformed HTTP long poll response. Cannot determine multipart/mixed boundary.");
}
context.Boundary = new byte[2 + context.ParsingIndex];
context.Boundary[0] = 0x0D;
context.Boundary[1] = 0x0A;
Buffer.BlockCopy(this.buffer, this.offset, context.Boundary, 2, context.ParsingIndex);
this.ConsumeBytes(context.ParsingIndex + 2);
context.ParsingIndex = 0;
context.State = ParsingState.ContentTypeHeader;
}
return(result);
}
bool ParseAfterBoundary(MultipartMimeParsingContex context)
{
if (this.count >= 2)
{
if (this.buffer[this.offset] == 0x0D && this.buffer[this.offset + 1] == 0x0A)
{
// another MIME part is expected
this.ConsumeBytes(2);
context.State = ParsingState.ContentTypeHeader;
}
else if (this.buffer[this.offset] == 0x2D && this.buffer[this.offset + 1] == 0x2D)
{
// another MIME part is not expected
this.ConsumeBytes(2);
context.State = ParsingState.Epilogue;
}
else
{
throw new InvalidOperationException("Malformed HTTP long poll response. Protocol violation after MIME boundary.");
}
}
return(this.count > 0);
}