return folly::fibers::runInMainContext()

in mcrouter/lib/network/ThriftTransport.cpp [81:142]
60 lines of code
6 McCabe index (conditional complexity)

  return folly::fibers::runInMainContext(
      [this]() -> folly::AsyncTransportWrapper::UniquePtr {
        auto expectedSocket = createAsyncSocket(eventBase_, connectionOptions_);
        if (expectedSocket.hasError()) {
          LOG_FAILURE(
              "ThriftTransport",
              failure::Category::kBadEnvironment,
              "{}",
              expectedSocket.error().what());
          return {};
        }
        auto socket = std::move(expectedSocket).value();

        auto sockAddressExpected = getSocketAddress(connectionOptions_);
        if (sockAddressExpected.hasError()) {
          const auto& ex = sockAddressExpected.error();
          LOG_FAILURE(
              "ThriftTransport",
              failure::Category::kBadEnvironment,
              "{}",
              ex.what());
          return {};
        }
        folly::SocketAddress address = std::move(sockAddressExpected).value();
        auto socketOptions = createSocketOptions(address, connectionOptions_);
        connectionState_ = ConnectionState::Connecting;

        const auto securityMech =
            connectionOptions_.accessPoint->getSecurityMech();
        if (securityMech == SecurityMech::TLS_TO_PLAINTEXT) {
          socket->setSendTimeout(connectionOptions_.writeTimeout.count());
          socket->getUnderlyingTransport<AsyncTlsToPlaintextSocket>()->connect(
              this,
              address,
              connectionOptions_.connectTimeout,
              std::move(socketOptions));
        } else if (securityMech == SecurityMech::TLS) {
          socket->setSendTimeout(connectionOptions_.writeTimeout.count());
          socket->getUnderlyingTransport<folly::AsyncSSLSocket>()->connect(
              this,
              address,
              connectionOptions_.connectTimeout.count(),
              socketOptions);
        } else if (securityMech == SecurityMech::TLS13_FIZZ) {
          auto fizzClient = socket->getUnderlyingTransport<McFizzClient>();
          fizzClient->setSendTimeout(connectionOptions_.writeTimeout.count());
          fizzClient->connect(
              this,
              address,
              connectionOptions_.connectTimeout.count(),
              socketOptions);
        } else {
          DCHECK(securityMech == SecurityMech::NONE);
          socket->setSendTimeout(connectionOptions_.writeTimeout.count());
          socket->getUnderlyingTransport<folly::AsyncSocket>()->connect(
              this,
              address,
              connectionOptions_.connectTimeout.count(),
              socketOptions);
        }
        return socket;
      });