/// <summary>Parses incoming data into an HTTP request</summary>
/// <param name="buffer">Buffer containing the received data</param>
/// <param name="receivedByteCount">Number of bytes in the receive buffer</param>
private void parseRequest(byte[] buffer, int receivedByteCount) {
ArraySegment<byte> data = new ArraySegment<byte>(buffer, 0, receivedByteCount);
while(data.Count > 0) {
Response response; // Response that will be delivered to the client
bool dropConnection = false; // Whether to close the connection
try {
// Try to parse a complete request from the bytes the client has sent to us.
// If there isn't enough data available yet, we exit here and hopefully the
// next time data arrives it will be enough to complete the request entity.
Request request = this.parser.ProcessBytes(data.Array, data.Offset, data.Count);
if(request == null) {
break;
}
// We've got an actual request. Now let's handle it using the implementation
// provided by the deriving class from the user!
response = ProcessRequest(request);
}
catch(Exceptions.HttpException httpException) {
response = new Response(httpException.StatusCode, httpException.Message);
dropConnection = true;
}
catch(Exception exception) {
response = new Response(StatusCode.S500_Internal_Server_Error, exception.Message);
dropConnection = true;
}
// Transform the response entity into a stream of bytes and send it back to
// the client. If any additional data has to be transmitted, this will be handled
// by the attachment transmitter.
byte[] responseBytes = ResponseFormatter.Format(response);
this.socket.Send(responseBytes); // TODO: Can get an ObjectDisposedException here!
// TODO: Evil hack!
if(response.AttachedStream != null) {
this.socket.Send(((MemoryStream)response.AttachedStream).GetBuffer());
}
// TODO: Respect the keep-alive request header here
// If keep-alive is not set, we should close the connection here!
if(dropConnection) {
Drop();
} else {
// Now take the remaining data out of the parser and bring the parser back into
// its initial state so it can begin parsing the next request
data = this.parser.GetRemainingData();
this.parser.Reset();
}
}
}
/// <summary>Processes the provided request and generates a server response</summary>
/// <param name="request">Request to be processed by the server</param>
/// <returns>The response to the server request</returns>
protected virtual Response ProcessRequest(Request request) {
#if true // GENERATE_DUMMY_RESPONSE
Console.WriteLine(
DateTime.Now.ToString() + " Processed request for " + request.Uri
);
// Here's the HTML document we want to send to the client
MemoryStream messageMemory = new MemoryStream();
StreamWriter writer = new StreamWriter(messageMemory, Encoding.UTF8);
writer.WriteLine("<html>");
writer.WriteLine("<head><title>Hello World</title></head>");
writer.WriteLine("<body><small>Hello World from the Nuclex Web Server</small></body>");
writer.WriteLine("</html>");
writer.Flush();
// Prepare the response message
Response theResponse = new Response(StatusCode.S200_OK);
// Add some random headers web server's like to provider
theResponse.Headers.Add("Cache-Control", "private");
theResponse.Headers.Add("Content-Type", "text/html; charset=UTF-8");
theResponse.Headers.Add("Date", "Wed, 30 Jul 2008 14:01:06 GMT");
theResponse.Headers.Add("Server", "Nuclex");
// Attach the HTML document to our response
theResponse.AttachStream(messageMemory);
// Now comes the important part, specify how many bytes we're going to
// transmit.
// TODO: This should be done by parseRequest()
// Whether it's needed or not depends on the transport protocol used
messageMemory.Position = 0;
theResponse.Headers.Add("Content-Length", messageMemory.Length.ToString());
#endif
return theResponse;
}
/// <summary>
/// Convert the provided response into the HTTP response transport format
/// </summary>
/// <param name="response">Response that will be converted</param>
/// <returns>
/// An array of bytes containing the response in the HTTP response format
/// </returns>
public static byte[] Format(Response response) {
// Make sure the status code is in a valid numerical range. We will also need
// this int later to avoid .NETs enum to string conversion helpfulness
int intStatusCode = (int)response.StatusCode;
if((intStatusCode < 100) || (intStatusCode > 599)) {
throw new InvalidOperationException("Invalid status code in response");
}
// Build a usable status message string. If the request processor specified
// null for the status message, we try to replace it with the default message
// for the given status code. If that also doesn't work, we'll send an empty
// status message.
string statusMessage = response.StatusMessage;
if(statusMessage == null) {
statusMessage = StatusCodeHelper.GetDefaultDescription(response.StatusCode);
if(statusMessage == null) {
statusMessage = string.Empty;
}
}
// Calculate the total size of the return packet
int combinedLength;
int versionLength, statusMessageLength;
int[,] headerLengths;
// Status line
{
// Sum up the length of the constant parts of the reply
// <Version> SP:1 <StatusCode:3> SP:1 <StatusMessage> CRLF:2 <Headers> CRLF:2
combinedLength = 1 + 3 + 1 + 2 + 2; // SP + StatusCode + SP + CRLF + CRLF
// Add the length of the HTTP version and status message
versionLength = iso88591Encoding.GetByteCount(response.Version);
combinedLength += versionLength;
statusMessageLength = iso88591Encoding.GetByteCount(statusMessage);
combinedLength += statusMessageLength;
}
// Headers
{
// Add the constant per-header overhead of 4 bytes
// <FieldName> DCOLON:1 SP:1 <FieldValue> CRLF:2
combinedLength += response.Headers.Count * 4;
headerLengths = new int[response.Headers.Count, 2];
// Now sum up the length of the dynamic parts in all header fields
int headerIndex = 0;
foreach(KeyValuePair<string, string> header in response.Headers) {
headerLengths[headerIndex, 0] = iso88591Encoding.GetByteCount(header.Key);
headerLengths[headerIndex, 1] = iso88591Encoding.GetByteCount(header.Value);
combinedLength += headerLengths[headerIndex, 0] + headerLengths[headerIndex, 1];
++headerIndex;
}
}
// Now that we know the length of the response message, we can set up a buffer and
// construct the response in it.
byte[] responseBytes = new byte[combinedLength];
int responseByteIndex = 0;
// Write the HTTP protocol version
iso88591Encoding.GetBytes(
response.Version, 0, response.Version.Length, responseBytes, 0
);
responseByteIndex += versionLength;
responseBytes[responseByteIndex] = SP;
++responseByteIndex;
//IFormatProvider
// Write the status code
iso88591Encoding.GetBytes(
intStatusCode.ToString(), 0, 3, responseBytes, responseByteIndex
); // TODO: use explicit locale
responseByteIndex += 3;
responseBytes[responseByteIndex] = SP;
++responseByteIndex;
// Write the status message
iso88591Encoding.GetBytes(
statusMessage, 0, statusMessage.Length,
responseBytes, responseByteIndex
);
responseByteIndex += statusMessageLength;
responseBytes[responseByteIndex] = CR;
++responseByteIndex;
responseBytes[responseByteIndex] = LF;
++responseByteIndex;
// Write headers
{
int headerIndex = 0;
foreach(KeyValuePair<string, string> header in response.Headers) {
// Write header name
iso88591Encoding.GetBytes(
header.Key, 0, header.Key.Length, responseBytes, responseByteIndex
);
responseByteIndex += headerLengths[headerIndex, 0];
responseBytes[responseByteIndex] = DC;
++responseByteIndex;
responseBytes[responseByteIndex] = SP; // not in RFC, but common practice
++responseByteIndex;
// Write header value
iso88591Encoding.GetBytes(
header.Value, 0, header.Value.Length, responseBytes, responseByteIndex
);
responseByteIndex += headerLengths[headerIndex, 1];
responseBytes[responseByteIndex] = CR;
++responseByteIndex;
responseBytes[responseByteIndex] = LF; // not in RFC, but common practice
++responseByteIndex;
++headerIndex;
}
}
responseBytes[responseByteIndex] = CR;
++responseByteIndex;
responseBytes[responseByteIndex] = LF; // not in RFC, but common practice
++responseByteIndex;
return responseBytes;
}