public async Task ExecuteAsync()
{
try
{
// Read the request header, minimum required prior processing the request;
await _request.WaitForHttpHeaderAsync();
_logger.Debug($"{_request.Header.Method} {_request.Header.Uri}");
// Got the header.
// Very likely that we just woke up from a keep-alive sleep,
// Abort the watch dog to avoid being killed.
if (_keepAliveService.IsRegistered(_connection))
{
_keepAliveService.Deregister(_connection);
}
// Process the request-response
SetDefaultResponseHeaders();
await ProcessRequestResponseAsync();
// Before continuing to the next HTTP session in the connection loop,
// the response header + body of this message must be completely written
// (or abort the connection),
// otherwise it causes unexpected behaviour for the other HTTP client.
await _response.Body.CompleteAsync();
// If we promised the client to keep alive, do it.
if (!StringCI.Compare(
_response.Header[HttpKeys.Connection], HttpKeys.CloseValue))
{
_keepAliveService.Register(_connection);
}
}
catch (HttpBadRequestException ex)
{
// Caused by malformed HTTP request message
// sent by the client;
// We'll return with an 400 BadRequest
_logger.Warn(ex.Message);
await TryRespondErrorAsync(
400,
$"<h1>Bad Request</h1><br />{ex.ToString()}");
}
catch (TcpException) {
throw;
}
catch (Exception ex) {
// Unexpected error caused by us,
// We'll return with an internal error
_logger.Error(ex);
await TryRespondErrorAsync(
500,
$"<h1>Internal Server Error</h1><br />{ex.ToString()}");
// Let the connection loop handle this exception,
// probably by closing the connection.
throw;
}
}
/// <summary>
/// Based on the request header and keep-alive service state,
/// should we keep the current connection alive?
/// </summary>
bool ShoudKeepAlive()
{
if (false == _keepAliveService.CanRegister(_connection))
{
return(false);
}
// https://tools.ietf.org/html/rfc7230#section-6
// If the "close" connection option is present, the connection will
// not persist after the current response; else,
if (_request.Header.ContainsKey(HttpKeys.Connection) &&
StringCI.Compare(_request.Header[HttpKeys.Connection], HttpKeys.CloseValue))
{
return(false);
}
// If the received protocol is HTTP/1.1 (or later), the connection
// will persist after the current response; else,
if (_request.Header.Protocol == HttpProtocol.Http11)
{
return(true);
}
// If the received protocol is HTTP / 1.0, the "keep-alive" connection
// option is present, the recipient is not a proxy, and the recipient
// wishes to honor the HTTP/ 1.0 "keep-alive" mechanism, the
// connection will persist after the current response; otherwise,
if (_request.Header.Protocol == HttpProtocol.Http10 &&
_request.Header.ContainsKey(HttpKeys.Connection) &&
StringCI.Compare(_request.Header[HttpKeys.Connection], HttpKeys.KeepAliveValue))
{
return(true);
}
// Else, the connection will close after the current response.
return(false);
}