From 40b687dc18d546304909fa3af8a87e14b9fe5dd5 Mon Sep 17 00:00:00 2001
From: KoalaSat <yv1vtrul@duck.com>
Date: Sat, 30 Dec 2023 16:01:08 +0000
Subject: [PATCH] Robohash gereator queue (#1035)

Robohash generator queue
---
 .../RobotAvatar/RobohashGenerator.ts          | 130 +++++++++++-------
 frontend/src/models/Federation.model.ts       |   2 +-
 2 files changed, 84 insertions(+), 48 deletions(-)

diff --git a/frontend/src/components/RobotAvatar/RobohashGenerator.ts b/frontend/src/components/RobotAvatar/RobohashGenerator.ts
index 2d25a89f..8f6c1adc 100644
--- a/frontend/src/components/RobotAvatar/RobohashGenerator.ts
+++ b/frontend/src/components/RobotAvatar/RobohashGenerator.ts
@@ -1,15 +1,75 @@
+interface Task {
+  robohash: Robohash;
+  resolves: ((result: string) => void)[];
+  rejects: ((reason?: Error) => void)[];
+}
+
+interface Robohash {
+  hash: string;
+  size: 'small' | 'large';
+  cacheKey: string;
+}
+
+interface RoboWorker {
+  worker: Worker;
+  busy: boolean;
+}
+
 class RoboGenerator {
   private assetsCache: Record<string, string> = {};
-  private assetsPromises: Record<string, Promise<string>> = {};
-  private readonly workers: Worker[] = [];
+
+  private readonly workers: RoboWorker[] = [];
+  private readonly queue: Task[] = [];
 
   constructor() {
     // limit to 8 workers
-    const numCores = Math.min(navigator.hardwareConcurrency || 1, 8);
+    const numCores = 8;
 
     for (let i = 0; i < numCores; i++) {
       const worker = new Worker(new URL('./robohash.worker.ts', import.meta.url));
-      this.workers.push(worker);
+      worker.onmessage = this.assignTasksToWorkers.bind(this);
+      this.workers.push({ worker, busy: false });
+    }
+  }
+
+  private assignTasksToWorkers() {
+    const availableWorker = this.workers.find((w) => !w.busy);
+
+    if (availableWorker) {
+      const task = this.queue.shift();
+      if (task) {
+        availableWorker.busy = true;
+        availableWorker.worker.postMessage(task.robohash);
+
+        // Clean up the event listener and free the worker after receiving the result
+        const cleanup = () => {
+          availableWorker.worker.removeEventListener('message', completionCallback);
+          availableWorker.busy = false;
+        };
+
+        // Resolve the promise when the task is completed
+        const completionCallback = (event: MessageEvent) => {
+          if (event.data.cacheKey === task.robohash.cacheKey) {
+            const { cacheKey, imageUrl } = event.data;
+
+            // Update the cache and resolve the promise
+            this.assetsCache[cacheKey] = imageUrl;
+
+            cleanup();
+
+            task.resolves.forEach((f) => f(imageUrl));
+          }
+        };
+
+        availableWorker.worker.addEventListener('message', completionCallback);
+
+        // Reject the promise if an error occurs
+        availableWorker.worker.addEventListener('error', (error) => {
+          cleanup();
+
+          task.rejects.forEach((f) => f(new Error(error.message)));
+        });
+      }
     }
   }
 
@@ -20,53 +80,29 @@ class RoboGenerator {
     const cacheKey = `${size}px;${hash}`;
     if (this.assetsCache[cacheKey]) {
       return this.assetsCache[cacheKey];
-    } else if (cacheKey in this.assetsPromises) {
-      return await this.assetsPromises[cacheKey];
-    }
+    } else {
+      return new Promise((resolve, reject) => {
+        let task = this.queue.find((t) => t.robohash.cacheKey === cacheKey);
 
-    const workerIndex = Object.keys(this.assetsPromises).length % this.workers.length;
-    const worker = this.workers[workerIndex];
+        if (!task) {
+          task = {
+            robohash: {
+              hash,
+              size,
+              cacheKey,
+            },
+            resolves: [],
+            rejects: [],
+          };
+          this.queue.push(task);
+        }
 
-    this.assetsPromises[cacheKey] = new Promise<string>((resolve, reject) => {
-      // const avatarB64 = async_generate_robohash(hash, size == 'small' ? 80 : 256).then((avatarB64)=> resolve(`data:image/png;base64,${avatarB64}`));
-      // Create a message object with the necessary data
-      const message = { hash, size, cacheKey, workerIndex };
+        task.resolves.push(resolve);
+        task.rejects.push(reject);
 
-      // Listen for messages from the worker
-      const handleMessage = (event: MessageEvent) => {
-        const { cacheKey, imageUrl } = event.data;
-
-        // Update the cache and resolve the promise
-        this.assetsCache[cacheKey] = imageUrl;
-        delete this.assetsPromises[cacheKey];
-        resolve(imageUrl);
-      };
-
-      // Add the event listener for messages
-      worker.addEventListener('message', handleMessage);
-
-      // Send the message to the worker
-      worker.postMessage(message);
-
-      // Clean up the event listener after receiving the result
-      const cleanup = () => {
-        worker.removeEventListener('message', handleMessage);
-      };
-
-      // Reject the promise if an error occurs
-      worker.addEventListener('error', (error) => {
-        cleanup();
-        reject(error);
+        this.assignTasksToWorkers();
       });
-
-      // Reject the promise if the worker times out
-      setTimeout(() => {
-        cleanup();
-        reject(new Error('Generation timed out'));
-      }, 5000); // Adjust the timeout duration as needed
-    });
-
-    return await this.assetsPromises[cacheKey];
+    }
   };
 }
 
diff --git a/frontend/src/models/Federation.model.ts b/frontend/src/models/Federation.model.ts
index 7b47e541..09286162 100644
--- a/frontend/src/models/Federation.model.ts
+++ b/frontend/src/models/Federation.model.ts
@@ -17,7 +17,7 @@ export class Federation {
   constructor() {
     this.coordinators = Object.entries(defaultFederation).reduce(
       (acc: Record<string, Coordinator>, [key, value]: [string, any]) => {
-        if (getHost() !== '127.0.0.1:8000' && key == 'local') {
+        if (getHost() !== '127.0.0.1:8000' && key === 'local') {
           // Do not add `Local Dev` unless it is running on localhost
           return acc;
         } else {