override suspend fun performUpgrade()

in ktor-server/ktor-server-jetty/jvm/src/io/ktor/server/jetty/internal/JettyUpgradeImpl.kt [21:61]
34 lines of code
2 McCabe index (conditional complexity)

    override suspend fun performUpgrade(
        upgrade: OutgoingContent.ProtocolUpgrade,
        servletRequest: HttpServletRequest, servletResponse: HttpServletResponse,
        engineContext: CoroutineContext, userContext: CoroutineContext
    ) {
        // Jetty doesn't support Servlet API's upgrade, so we have to implement our own

        val connection = servletRequest.getAttribute(HttpConnection::class.qualifiedName) as Connection
        val endPoint = connection.endPoint

        // for upgraded connections IDLE timeout should be significantly increased
        endPoint.idleTimeout = TimeUnit.MINUTES.toMillis(60L)

        withContext(engineContext + CoroutineName("upgrade-scope")) {
            try {
                coroutineScope {
                    val inputChannel = ByteChannel(autoFlush = true)
                    val reader = EndPointReader(endPoint, coroutineContext, inputChannel)
                    val writer = endPointWriter(endPoint)
                    val outputChannel = writer.channel

                    servletRequest.setAttribute(HttpConnection.UPGRADE_CONNECTION_ATTRIBUTE, reader)
                    if (endPoint is AbstractEndPoint) {
                        endPoint.upgrade(reader)
                    }
                    val upgradeJob = upgrade.upgrade(
                        inputChannel, outputChannel, coroutineContext,
                        coroutineContext + userContext
                    )

                    upgradeJob.invokeOnCompletion {
                        inputChannel.cancel()
                        outputChannel.close()
                        cancel()
                    }
                }
            } finally {
                connection.close()
            }
        }
    }