implement dxb over http, goodbye messages, improve endpoint online de…

…tection

compiler/compiler.ts

@@ -79,7 +79,7 @@ export class DatexResponse<T> {
 
 
 export const ProtocolDataTypesMap = [
-    "REQUEST", "RESPONSE", "DATA", "TMP_SCOPE", "LOCAL", "HELLO", "DEBUGGER", "SOURCE_MAP", "UPDATE"
+    "REQUEST", "RESPONSE", "DATA", "TMP_SCOPE", "LOCAL", "HELLO", "DEBUGGER", "SOURCE_MAP", "UPDATE", "GOODBYE"
 ]
 
 

compiler/protocol_types.ts

@@ -11,4 +11,5 @@ export enum ProtocolDataType {
     DEBUGGER    = 6, // get a debugger for a scope
     SOURCE_MAP  = 7, // send a source map for a scope
     UPDATE      = 8, // like normal request, but don't propgate updated pointer values back to sender (prevent recursive loop)
+    GOODBYE     = 9, // info message that endpoint is offline
 }

network/datex-http-channel.ts

@@ -0,0 +1,25 @@
+/**
+ * Send DATEX blocks to a server with a HTTPComInterface
+ * (listening to POST requests on /datex-http).
+ * No response is returned.
+ * 
+ * This is not the same as datex-over-http implemented in UIX
+ * that send unsigned/unencrypted DATEX scripts to an HTTP server
+ */
+export function sendDatexViaHTTPChannel(dxb: ArrayBuffer, origin = window.location.origin) {
+
+	// fallback to sendBeacon for firefox until fetch keepalive implemented
+	if (navigator.userAgent.includes("Firefox/")) {
+		navigator.sendBeacon(origin + "/datex-http", dxb);
+	}
+	else {
+		fetch(origin + "/datex-http", {
+			method:'post',
+			headers:{
+				'Content-Type': 'application/datex',
+			},
+			body: dxb,
+			keepalive: true
+		})
+	}
+}

network/supranet.ts

@@ -25,6 +25,7 @@ import { endpoint_config } from "../runtime/endpoint_config.ts";
 import { endpoint_name, UnresolvedEndpointProperty } from "../datex_all.ts";
 import { Datex } from "../mod.ts";
 import { Storage } from "../runtime/storage.ts";
+import { sendDatexViaHTTPChannel } from "./datex-http-channel.ts";
 const logger = new Logger("DATEX Supranet");
 
 // entry point to connect to the datex network
@@ -152,6 +153,12 @@ export class Supranet {
         // TODO: (does not work because response never reaches endpoint if valid endpoint already exists in network)
         // Crypto.validateOwnKeysAgainstNetwork();
 
+        // send goodbye on process close
+        const byeDatex = <ArrayBuffer> await Datex.Compiler.compile("", [], {type:Datex.ProtocolDataType.GOODBYE, sign:true, flood:true, __routing_ttl:10})
+        globalThis.addEventListener("beforeunload", () => {
+            sendDatexViaHTTPChannel(byeDatex);
+        })
+
         return connected;
     }
 

runtime/runtime.ts

@@ -1796,6 +1796,10 @@ export class Runtime {
             console.log("Scope error occured, cannot get the original error here!");
             return;
         }
+
+        // assume sender endpoint is online now
+        if (header.sender && header.signed) header.sender.setOnline(true)
+
         // return error to sender (if request)
         if (header.type == ProtocolDataType.REQUEST) {
             // is not a DatexError -> convert to DatexError
@@ -1839,6 +1843,9 @@ export class Runtime {
 
         const unique_sid = header.sid+"-"+header.return_index;
 
+        // assume sender endpoint is online now
+        if (header.sender && header.signed) header.sender.setOnline(true)
+
         // return global result to sender (if request)
         if (header.type == ProtocolDataType.REQUEST) {
             this.datexOut(["?", [return_value], {type:ProtocolDataType.RESPONSE, to:header.sender, return_index:header.return_index, encrypt:header.encrypted, sign:header.signed}], header.sender, header.sid, false);
@@ -1871,19 +1878,38 @@ export class Runtime {
 
         // hello (also temp: get public keys)
         else if (header.type == ProtocolDataType.HELLO) {
-            if (return_value) {
+            if (!header.sender) logger.error("Invalid HELLO message, no sender");
+            else if (return_value) {
                 try {
-                    let keys_updated = await Crypto.bindKeys(header.sender, ...<[ArrayBuffer,ArrayBuffer]>return_value);
+                    const keys_updated = await Crypto.bindKeys(header.sender, ...<[ArrayBuffer,ArrayBuffer]>return_value);
                     if (header.routing?.ttl)
                         header.routing.ttl--;
+
+                    // set online to true (even if HELLO message not signed)
+                    header.sender.setOnline(true)
                     logger.debug("HELLO ("+header.sid+"/" + header.inc+ "/" + header.return_index + ") from " + header.sender +  ", keys "+(keys_updated?"":"not ")+"updated, ttl = " + header.routing?.ttl);
                 }
                 catch (e) {
                     logger.error("Invalid HELLO keys");
                 }
             }
-            else logger.debug("HELLO from " + header.sender +  ", no keys, ttl = " + header.routing?.ttl);
+            else {
+                // set online to true (even if HELLO message not signed)
+                header.sender.setOnline(true)
+                logger.debug("HELLO from " + header.sender +  ", no keys, ttl = " + header.routing?.ttl);
+            }
         }
+
+        else if (header.type == ProtocolDataType.GOODBYE) {
+            if (header.signed && header.sender) {
+                logger.debug("GOODBYE from " + header.sender)
+                header.sender.setOnline(false)
+            }
+            else {
+                logger.error("ignoring unsigned GOODBYE message")
+            }
+        }
+
 
         else if (header.type == ProtocolDataType.DEBUGGER) {
             logger.success("DEBUGGER ?", return_value)
@@ -5015,7 +5041,7 @@ export class Runtime {
                     catch {}
                 }).filter(o => o && !(o.equals(Runtime.endpoint) || o.equals(SCOPE.sender))))
             ];
-            if (origins.length > 2) {
+            if (origins.length > 1) {
                 logger.debug("pre-fetching online state for "+ origins.length + " endpoints")
                 await Promise.race([
                     Promise.all(origins.map(origin => origin.isOnline())),

types/addressing.ts

@@ -341,6 +341,17 @@ export class Endpoint extends Target {
 		this.#onlinePointer.onGargabeCollection(()=> clearInterval(interval));
 		return this.#onlinePointer;
 	}
+
+	/**
+	 * Override online state (e.g. when retrieving a GOODBYE or other message)
+	 * @param online 
+	 */
+	public setOnline(online = true) {
+		this.#online = new Promise(resolve => resolve(online));
+		this.#current_online = online;
+		if (this.#onlinePointer) this.#onlinePointer.val = online;
+	}
+
 	// returns (cached) online status
 	public async isOnline(): Promise<boolean> {
 		if (Runtime.endpoint.equals(this) || Runtime.main_node?.equals(this) || this as Endpoint === LOCAL_ENDPOINT) return true; // is own endpoint or main node

utils/debug-cookie.ts

@@ -8,6 +8,7 @@ export function debugMode(enable = true) {
 	console.log("[debug mode " + (enable ? "enabled" : "disabled") + "]");
 	if (enable) setCookie("datex-debug", "true")
 	else setCookie("datex-debug", "");
+	window.location.reload()
 }