JettyServletAdapter.kt

package com.hexagonkt.http.server.jetty

import com.hexagonkt.core.Jvm
import com.hexagonkt.core.fieldsMapOf
import com.hexagonkt.http.model.HttpProtocol
import com.hexagonkt.http.model.HttpProtocol.*
import com.hexagonkt.http.server.HttpServer
import com.hexagonkt.http.server.HttpServerFeature
import com.hexagonkt.http.server.HttpServerFeature.ZIP
import com.hexagonkt.http.server.HttpServerPort
import com.hexagonkt.http.server.HttpServerSettings
import com.hexagonkt.http.server.servlet.ServletFilter
import jakarta.servlet.DispatcherType
import jakarta.servlet.MultipartConfigElement
import org.eclipse.jetty.alpn.server.ALPNServerConnectionFactory
import org.eclipse.jetty.ee10.servlet.DefaultServlet
import org.eclipse.jetty.ee10.servlet.ServletContextHandler
import org.eclipse.jetty.ee10.servlet.ServletContextHandler.NO_SESSIONS
import org.eclipse.jetty.ee10.servlet.ServletHolder
import org.eclipse.jetty.http2.server.HTTP2ServerConnectionFactory
import org.eclipse.jetty.server.*
import org.eclipse.jetty.server.handler.gzip.GzipHandler
import org.eclipse.jetty.util.VirtualThreads
import org.eclipse.jetty.util.VirtualThreads.getDefaultVirtualThreadsExecutor
import org.eclipse.jetty.util.ssl.SslContextFactory
import org.eclipse.jetty.util.thread.ExecutorThreadPool
import org.eclipse.jetty.util.thread.QueuedThreadPool
import org.eclipse.jetty.util.thread.ThreadPool
import java.security.KeyStore
import java.util.*
import org.eclipse.jetty.server.Server as JettyServer

/**
 * Implements [HttpServerPort] using [JettyServer].
 */
class JettyServletAdapter(
    private val maxThreads: Int = 200,
    private val minThreads: Int = 8,

    private val acceptors: Int = -1,
    private val selectors: Int = -1,

    private val sendDateHeader: Boolean = false,
    private val sendServerVersion: Boolean = false,
    private val sendXPoweredBy: Boolean = false,
    private val useVirtualThreads: Boolean = false,
) : HttpServerPort {

    private var jettyServer: JettyServer? = null

    constructor() : this(
        maxThreads = 200,
        minThreads = 8,

        acceptors = -1,
        selectors = -1,

        sendDateHeader = false,
        sendServerVersion = false,
        sendXPoweredBy = false,
        useVirtualThreads = false,
    )

    init {
        if (useVirtualThreads)
            check(VirtualThreads.areSupported()) {
                val jvm = "JVM: ${Jvm.version}"
                "Virtual threads not supported or not enabled (--enable-preview) $jvm"
            }
    }

    override fun runtimePort(): Int =
        jettyConnector().localPort

    override fun started() =
        jettyServer?.isStarted ?: false

    private fun jettyConnector(): ServerConnector =
        jettyServer?.connectors?.get(0) as? ServerConnector ?: error("Jetty must have a connector")

    private fun createThreadPool(): ThreadPool =
        if (useVirtualThreads) {
            val virtualThreadPool = getDefaultVirtualThreadsExecutor()
            val threadPool = ExecutorThreadPool(maxThreads, minThreads)
            threadPool.virtualThreadsExecutor = virtualThreadPool
            threadPool
        }
        else {
            QueuedThreadPool(maxThreads, minThreads)
        }

    override fun startUp(server: HttpServer) {
        val settings = server.settings
        val serverInstance = JettyServer(createThreadPool())
        jettyServer = serverInstance

        val pathHandler = server.handler.addPrefix(settings.contextPath)

        val context = createServerContext(settings)
        val filter = ServletFilter(pathHandler)
        val filterBind = context.servletContext.addFilter("filters", filter)
        val dispatcherTypes = EnumSet.allOf(DispatcherType::class.java)
        filterBind.addMappingForUrlPatterns(dispatcherTypes, true, "/*")

        val servletHolder = ServletHolder("default", DefaultServlet())
        servletHolder.registration.setMultipartConfig(MultipartConfigElement("/tmp"))
        context.addServlet(servletHolder, "/*")

        val serverConnector =
            if (settings.sslSettings != null) setupSsl(settings, serverInstance)
            else ServerConnector(serverInstance, acceptors, selectors)

        serverConnector.host = settings.bindAddress.hostName
        serverConnector.port = settings.bindPort
        serverConnector.connectionFactories
            .filterIsInstance<HttpConnectionFactory>()
            .map { it.httpConfiguration }
            .map {
                it.sendDateHeader = sendDateHeader
                it.sendServerVersion = sendServerVersion
                it.sendXPoweredBy = sendXPoweredBy
            }

        serverInstance.connectors = arrayOf(serverConnector)
        serverInstance.handler = context
        serverInstance.stopAtShutdown = true
        serverInstance.start()
    }

    override fun shutDown() {
        jettyServer?.stop()
    }

    override fun supportedProtocols(): Set<HttpProtocol> =
        setOf(HTTP, HTTPS, HTTP2)

    override fun supportedFeatures(): Set<HttpServerFeature> =
        setOf(ZIP)

    override fun options(): Map<String, *> =
        fieldsMapOf(
            JettyServletAdapter::maxThreads to maxThreads,
            JettyServletAdapter::minThreads to minThreads,
            JettyServletAdapter::acceptors to acceptors,
            JettyServletAdapter::selectors to selectors,
            JettyServletAdapter::sendDateHeader to sendDateHeader,
            JettyServletAdapter::sendServerVersion to sendServerVersion,
            JettyServletAdapter::sendXPoweredBy to sendXPoweredBy,
            JettyServletAdapter::useVirtualThreads to useVirtualThreads,
        )

    private fun createServerContext(settings: HttpServerSettings): ServletContextHandler {

        val context = ServletContextHandler(NO_SESSIONS)

        if (settings.zip)
            context.insertHandler(GzipHandler())

        return context
    }

    private fun setupSsl(
        settings: HttpServerSettings, serverInstance: JettyServer): ServerConnector {

        val httpConfiguration = HttpConfiguration()
        httpConfiguration.secureScheme = "https"
        httpConfiguration.securePort = settings.bindPort
        httpConfiguration.addCustomizer(SecureRequestCustomizer())

        val sslContextFactory = SslContextFactory.Server()
        val sslSettings = settings.sslSettings ?: error("SSL settings cannot be 'null'")
        sslContextFactory.needClientAuth = sslSettings.clientAuth

        val keyStore = sslSettings.keyStore
        if (keyStore != null) {
            val keyStorePassword = sslSettings.keyStorePassword
            val keyStoreStream = keyStore.openStream()
            sslContextFactory.keyStore = KeyStore.getInstance("pkcs12")
            sslContextFactory.keyStore.load(keyStoreStream, keyStorePassword.toCharArray())
            sslContextFactory.keyStorePassword = keyStorePassword
        }

        val trustStore = sslSettings.trustStore
        if (trustStore != null) {
            val trustStorePassword = sslSettings.trustStorePassword
            val trustStoreStream = trustStore.openStream()
            sslContextFactory.trustStore = KeyStore.getInstance("pkcs12")
            sslContextFactory.trustStore.load(trustStoreStream, trustStorePassword.toCharArray())
            sslContextFactory.setTrustStorePassword(trustStorePassword)
        }

        return if (settings.protocol != HTTP2)
            ServerConnector(
                serverInstance,
                SslConnectionFactory(sslContextFactory, "http/1.1"),
                HttpConnectionFactory(httpConfiguration)
            )
        else {
            val alpn = ALPNServerConnectionFactory()
            ServerConnector(
                serverInstance,
                SslConnectionFactory(sslContextFactory, alpn.protocol),
                alpn,
                HTTP2ServerConnectionFactory(httpConfiguration),
                HttpConnectionFactory(httpConfiguration)
            )
        }
    }
}