New aqua (#969)

src/helpers/waitService.ts

@@ -0,0 +1,46 @@
+/**
+ * Creates service that will wait for a response from external peers.
+ */
+import {genUUID} from "../particle";
+import log from "loglevel";
+import {Service} from "../service";
+import {deleteService, registerService} from "../globalState";
+import {delay} from "../utils";
+
+interface NamedPromise<T> {
+    promise: Promise<T>,
+    name: string
+}
+
+/**
+ * Generates a service and a name of a service.
+ * Name should be used in a script.
+ * Promise will wait a result from a script or will be resolved after `ttl` milliseconds.
+ * @param ttl
+ */
+export function waitResult(ttl: number): NamedPromise<any[]> {
+    return waitService(genUUID(), (args: any[]) => args, ttl)
+}
+
+export function waitService<T>(functionName: string, func: (args: any[]) => T, ttl: number): NamedPromise<T> {
+    let serviceName = `${functionName}-${genUUID()}`;
+    log.info(`Create waiting service '${serviceName}'`)
+    let service = new Service(serviceName)
+    registerService(service)
+
+    let promise: Promise<T> = new Promise(function (resolve) {
+        service.registerFunction("", (args: any[]) => {
+            resolve(func(args))
+            return {}
+        })
+    })
+
+    let timeout = delay<T>(ttl, "Timeout on waiting " + serviceName)
+
+    return {
+        name: serviceName,
+        promise: Promise.race([promise, timeout]).finally(() => {
+            deleteService(serviceName)
+        })
+    }
+}