Websockets implementation

2 files changed, 128 insertions, 7 deletions

diff --git a/kvision-modules/kvision-server-ktor/src/main/kotlin/pl/treksoft/kvision/remote/KVModules.kt b/kvision-modules/kvision-server-ktor/src/main/kotlin/pl/treksoft/kvision/remote/KVModules.kt
index 956e7301..e2edc175 100644
--- a/kvision-modules/kvision-server-ktor/src/main/kotlin/pl/treksoft/kvision/remote/KVModules.kt
+++ b/kvision-modules/kvision-server-ktor/src/main/kotlin/pl/treksoft/kvision/remote/KVModules.kt
@@ -31,17 +31,25 @@ import io.ktor.application.ApplicationCallPipeline
 import io.ktor.application.call
 import io.ktor.application.install
 import io.ktor.features.ContentNegotiation
+import io.ktor.http.cio.websocket.Frame
 import io.ktor.http.content.defaultResource
 import io.ktor.http.content.resources
 import io.ktor.http.content.static
 import io.ktor.jackson.jackson
 import io.ktor.routing.routing
 import io.ktor.util.AttributeKey
+import io.ktor.util.KtorExperimentalAPI
+import io.ktor.websocket.WebSocketServerSession
+import io.ktor.websocket.WebSockets
+import kotlinx.coroutines.channels.ReceiveChannel
+import kotlinx.coroutines.channels.SendChannel
+import kotlin.coroutines.CoroutineContext
 
 fun Application.kvisionInit(vararg modules: Module) {
     install(ContentNegotiation) {
         jackson()
     }
+    install(WebSockets)
     routing {
         static("/") {
             resources("assets")
@@ -72,3 +80,50 @@ class MainModule(private val application: Application) : AbstractModule() {
         bind(Application::class.java).toInstance(application)
     }
 }
+
+class WsSessionModule(private val webSocketSession: WebSocketServerSession) :
+    AbstractModule() {
+    override fun configure() {
+        bind(WebSocketServerSession::class.java).toInstance(webSocketSession)
+    }
+}
+
+class DummyWsSessionModule() : AbstractModule() {
+    override fun configure() {
+        bind(WebSocketServerSession::class.java).toInstance(DummyWebSocketServerSession())
+    }
+}
+
+class DummyWebSocketServerSession : WebSocketServerSession {
+    override val call: ApplicationCall
+        get() = throw UnsupportedOperationException()
+    override val coroutineContext: CoroutineContext
+        get() = throw UnsupportedOperationException()
+    override val incoming: ReceiveChannel<Frame>
+        get() = throw UnsupportedOperationException()
+    override var masking: Boolean
+        get() = throw UnsupportedOperationException()
+        set(value) {
+            throw UnsupportedOperationException()
+        }
+    override var maxFrameSize: Long
+        get() = throw UnsupportedOperationException()
+        set(value) {
+            throw UnsupportedOperationException()
+        }
+    override val outgoing: SendChannel<Frame>
+        get() = throw UnsupportedOperationException()
+
+    @UseExperimental(KtorExperimentalAPI::class)
+    override suspend fun close(cause: Throwable?) {
+        throw UnsupportedOperationException()
+    }
+
+    override suspend fun flush() {
+        throw UnsupportedOperationException()
+    }
+
+    override fun terminate() {
+        throw UnsupportedOperationException()
+    }
+}
diff --git a/kvision-modules/kvision-server-ktor/src/main/kotlin/pl/treksoft/kvision/remote/KVServiceManager.kt b/kvision-modules/kvision-server-ktor/src/main/kotlin/pl/treksoft/kvision/remote/KVServiceManager.kt
index d4985adf..0839a5c5 100644
--- a/kvision-modules/kvision-server-ktor/src/main/kotlin/pl/treksoft/kvision/remote/KVServiceManager.kt
+++ b/kvision-modules/kvision-server-ktor/src/main/kotlin/pl/treksoft/kvision/remote/KVServiceManager.kt
@@ -24,6 +24,10 @@ package pl.treksoft.kvision.remote
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import io.ktor.application.ApplicationCall
 import io.ktor.application.call
+import io.ktor.http.cio.websocket.CloseReason
+import io.ktor.http.cio.websocket.Frame
+import io.ktor.http.cio.websocket.close
+import io.ktor.http.cio.websocket.readText
 import io.ktor.request.receive
 import io.ktor.response.respond
 import io.ktor.routing.Route
@@ -33,7 +37,17 @@ import io.ktor.routing.options
 import io.ktor.routing.post
 import io.ktor.routing.put
 import io.ktor.util.pipeline.PipelineContext
+import io.ktor.websocket.WebSocketServerSession
+import io.ktor.websocket.webSocket
 import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.channels.ReceiveChannel
+import kotlinx.coroutines.channels.SendChannel
+import kotlinx.coroutines.channels.filterNotNull
+import kotlinx.coroutines.channels.map
+import kotlinx.coroutines.channels.mapNotNull
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.launch
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
 import kotlin.reflect.KClass
@@ -55,6 +69,8 @@ actual open class KVServiceManager<T : Any> actual constructor(val serviceClass:
         mutableMapOf()
     val optionsRequests: MutableMap<String, suspend PipelineContext<Unit, ApplicationCall>.(Unit) -> Unit> =
         mutableMapOf()
+    val webSocketRequests: MutableMap<String, suspend WebSocketServerSession.() -> Unit> =
+        mutableMapOf()
 
     val mapper = jacksonObjectMapper()
     var counter: Int = 0
@@ -72,7 +88,7 @@ actual open class KVServiceManager<T : Any> actual constructor(val serviceClass:
     ) {
         val routeDef = route ?: "route${this::class.simpleName}${counter++}"
         addRoute(method, "/kv/$routeDef") {
-            val service = call.injector.getInstance(serviceClass.java)
+            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
             val jsonRpcRequest = if (method == HttpMethod.GET) {
                 JsonRpcRequest(call.request.queryParameters["id"]?.toInt() ?: 0, "", listOf())
             } else {
@@ -113,7 +129,7 @@ actual open class KVServiceManager<T : Any> actual constructor(val serviceClass:
             throw UnsupportedOperationException("GET method is only supported for methods without parameters")
         val routeDef = route ?: "route${this::class.simpleName}${counter++}"
         addRoute(method, "/kv/$routeDef") {
-            val service = call.injector.getInstance(serviceClass.java)
+            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
             val jsonRpcRequest = call.receive<JsonRpcRequest>()
             if (jsonRpcRequest.params.size == 1) {
                 val param = getParameter<PAR>(jsonRpcRequest.params[0])
@@ -160,7 +176,7 @@ actual open class KVServiceManager<T : Any> actual constructor(val serviceClass:
             throw UnsupportedOperationException("GET method is only supported for methods without parameters")
         val routeDef = route ?: "route${this::class.simpleName}${counter++}"
         addRoute(method, "/kv/$routeDef") {
-            val service = call.injector.getInstance(serviceClass.java)
+            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
             val jsonRpcRequest = call.receive<JsonRpcRequest>()
             if (jsonRpcRequest.params.size == 2) {
                 val param1 = getParameter<PAR1>(jsonRpcRequest.params[0])
@@ -208,7 +224,7 @@ actual open class KVServiceManager<T : Any> actual constructor(val serviceClass:
             throw UnsupportedOperationException("GET method is only supported for methods without parameters")
         val routeDef = route ?: "route${this::class.simpleName}${counter++}"
         addRoute(method, "/kv/$routeDef") {
-            val service = call.injector.getInstance(serviceClass.java)
+            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
             val jsonRpcRequest = call.receive<JsonRpcRequest>()
             @Suppress("MagicNumber")
             if (jsonRpcRequest.params.size == 3) {
@@ -258,7 +274,7 @@ actual open class KVServiceManager<T : Any> actual constructor(val serviceClass:
             throw UnsupportedOperationException("GET method is only supported for methods without parameters")
         val routeDef = route ?: "route${this::class.simpleName}${counter++}"
         addRoute(method, "/kv/$routeDef") {
-            val service = call.injector.getInstance(serviceClass.java)
+            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
             val jsonRpcRequest = call.receive<JsonRpcRequest>()
             @Suppress("MagicNumber")
             if (jsonRpcRequest.params.size == 4) {
@@ -310,7 +326,7 @@ actual open class KVServiceManager<T : Any> actual constructor(val serviceClass:
             throw UnsupportedOperationException("GET method is only supported for methods without parameters")
         val routeDef = route ?: "route${this::class.simpleName}${counter++}"
         addRoute(method, "/kv/$routeDef") {
-            val service = call.injector.getInstance(serviceClass.java)
+            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
             val jsonRpcRequest = call.receive<JsonRpcRequest>()
             @Suppress("MagicNumber")
             if (jsonRpcRequest.params.size == 5) {
@@ -348,6 +364,51 @@ actual open class KVServiceManager<T : Any> actual constructor(val serviceClass:
     }
 
     /**
+     * Binds a given web socket connetion with a function of the receiver.
+     * @param function a function of the receiver
+     * @param route a route
+     */
+    protected actual inline fun <reified PAR1 : Any, reified PAR2 : Any> bind(
+        noinline function: suspend T.(ReceiveChannel<PAR1>, SendChannel<PAR2>) -> Unit,
+        route: String?
+    ) {
+        val routeDef = "route${this::class.simpleName}${counter++}"
+        webSocketRequests["/kv/$routeDef"] = {
+            val wsInjector = call.injector.createChildInjector(WsSessionModule(this))
+            val service = wsInjector.getInstance(serviceClass.java)
+            val requestChannel = incoming.mapNotNull { it as? Frame.Text }.map {
+                val jsonRpcRequest = getParameter<JsonRpcRequest>(it.readText())
+                if (jsonRpcRequest.params.size == 1) {
+                    getParameter<PAR1>(jsonRpcRequest.params[0])
+                } else {
+                    null
+                }
+            }.filterNotNull()
+            val responseChannel = Channel<PAR2>()
+            val session = this
+            coroutineScope {
+                launch {
+                    for (p in responseChannel) {
+                        val text = mapper.writeValueAsString(
+                            JsonRpcResponse(
+                                id = 0,
+                                result = mapper.writeValueAsString(p)
+                            )
+                        )
+                        outgoing.send(Frame.Text(text))
+                    }
+                    session.close(CloseReason(CloseReason.Codes.NORMAL, ""))
+                    session.close()
+                }
+                launch {
+                    function.invoke(service, requestChannel, responseChannel)
+                    if (!responseChannel.isClosedForReceive) responseChannel.close()
+                }
+            }
+        }
+    }
+
+    /**
      * Binds a given function of the receiver as a select options source
      * @param function a function of the receiver
      */
@@ -357,7 +418,7 @@ actual open class KVServiceManager<T : Any> actual constructor(val serviceClass:
     ) {
         val routeDef = "route${this::class.simpleName}${counter++}"
         addRoute(HttpMethod.POST, "/kv/$routeDef") {
-            val service = call.injector.getInstance(serviceClass.java)
+            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
             val jsonRpcRequest = call.receive<JsonRpcRequest>()
             if (jsonRpcRequest.params.size == 2) {
                 val param1 = getParameter<String?>(jsonRpcRequest.params[0])
@@ -431,4 +492,9 @@ fun <T : Any> Route.applyRoutes(serviceManager: KVServiceManager<T>) {
     serviceManager.optionsRequests.forEach { (path, handler) ->
         options(path, handler)
     }
+    serviceManager.webSocketRequests.forEach { (path, handler) ->
+        this.webSocket(path) {
+            handler()
+        }
+    }
 }