Function parserOnIncoming

lib/_http_server.js:1256–1387

(server, socket, state, req, keepAlive)

// new message. In this callback we setup the response object and pass it
// to the user.
function parserOnIncoming(server, socket, state, req, keepAlive) {
  resetSocketTimeout(server, socket, state);

  if (req.upgrade) {
    req.upgrade = req.method === 'CONNECT' ||
                  !!server.shouldUpgradeCallback(req);
    if (req.upgrade) {
      return 0;
    }
  }

  state.incoming.push(req);

  // If the writable end isn't consuming, then stop reading
  // so that we don't become overwhelmed by a flood of
  // pipelined requests that may never be resolved.
  if (!socket._paused) {
    const ws = socket._writableState;
    if (ws.needDrain || state.outgoingData >= socket.writableHighWaterMark) {
      socket._paused = true;
      // We also need to pause the parser, but don't do that until after
      // the call to execute, because we may still be processing the last
      // chunk.
      socket.pause();
    }
  }

  const res = new server[kServerResponse](req,
                                          {
                                            highWaterMark: socket.writableHighWaterMark,
                                            rejectNonStandardBodyWrites: server.rejectNonStandardBodyWrites,
                                          });
  res._keepAliveTimeout = server.keepAliveTimeout;
  res._maxRequestsPerSocket = server.maxRequestsPerSocket;
  res._onPendingData = updateOutgoingData.bind(undefined,
                                               socket, state);

  res.shouldKeepAlive = keepAlive;
  res[kUniqueHeaders] = server[kUniqueHeaders];

  if (onRequestStartChannel.hasSubscribers) {
    onRequestStartChannel.publish({
      request: req,
      response: res,
      socket,
      server,
    });
  }

  // Check if we should optimize empty requests (those without Content-Length or Transfer-Encoding headers)
  const shouldOptimize = server[kOptimizeEmptyRequests] === true && !hasBodyHeaders(req.headers);

  if (shouldOptimize) {
    // Fast processing where emitting 'data', 'end' and 'close' events is
    // skipped and data is dumped.
    // This avoids a lot of unnecessary overhead otherwise introduced by
    // stream.Readable life cycle rules. The downside is that this will
    // break some servers that read bodies for methods that don't have body headers.