void EvbHandshakeHelper::connectionReady()

in wangle/acceptor/EvbHandshakeHelper.cpp [86:136]
44 lines of code
3 McCabe index (conditional complexity)

void EvbHandshakeHelper::connectionReady(
    folly::AsyncTransport::UniquePtr transport,
    std::string nextProtocol,
    SecureTransportType secureTransportType,
    folly::Optional<SSLErrorEnum> sslErr) noexcept {
  DCHECK_EQ(transport->getEventBase(), handshakeEvb_);

  auto transition =
      tryTransition(HandshakeState::Started, HandshakeState::Callback);
  if (!transition.first) {
    VLOG(5) << "Ignoring call to connectionReady(), expected state to be "
            << static_cast<unsigned>(HandshakeState::Started)
            << " but actual state was "
            << static_cast<unsigned>(transition.second);
    return;
  }

  transport->detachEventBase();

  handshakeEvb_->runInLoop(
      [this,
       secureTransportType,
       sslErr,
       transport = std::move(transport),
       nextProtocol = std::move(nextProtocol)]() mutable {
        originalEvb_->runInEventBaseThread(
            [this,
             secureTransportType,
             sslErr,
             transport = std::move(transport),
             nextProtocol = std::move(nextProtocol)]() mutable {
              DCHECK(callback_);
              VLOG(5) << "calling underlying callback connectionReady";
              transport->attachEventBase(originalEvb_);

              // If a dropConnection call occured by the time this lambda runs,
              // we don't want to fire the callback. (See Case 2)
              if (dropConnectionGuard_.has_value()) {
                dropConnectionGuard_.reset();
                return;
              }

              callback_->connectionReady(
                  std::move(transport),
                  std::move(nextProtocol),
                  secureTransportType,
                  sslErr);
            });
      },
      /* thisIteration = */ true);
}