Move canvasToRedis to a worker thread

Fixes #68

packages/server/src/index.ts

@@ -6,6 +6,7 @@ import { ExpressServer } from "./lib/Express";
 import { SocketServer } from "./lib/SocketServer";
 import { OpenID } from "./lib/oidc";
 import { loadSettings } from "./lib/Settings";
+import "./workers/worker";
 
 const Logger = getLogger("MAIN");
 

packages/server/src/lib/Canvas.ts

@@ -4,6 +4,7 @@ import { Redis } from "./redis";
 import { SocketServer } from "./SocketServer";
 import { getLogger } from "./Logger";
 import { Pixel } from "@prisma/client";
+import { CanvasWorker } from "../workers/worker";
 
 const Logger = getLogger("CANVAS");
 
@@ -162,50 +163,29 @@ class Canvas {
   }
 
   /**
-   * Database pixels -> single Redis comma separated list of hex
-   * @returns 1D array of pixel values
+   * Converts database pixels to Redis string
+   *
+   * @worker
+   * @returns
    */
-  async canvasToRedis() {
-    const now = Date.now();
-    Logger.info("Starting canvasToRedis...");
-    const redis = await Redis.getClient();
+  canvasToRedis(): Promise<string[]> {
+    return new Promise((res) => {
+      Logger.info("Triggering canvasToRedis()");
+      const [width, height] = this.getCanvasConfig().size;
 
-    const dbpixels = await prisma.pixel.findMany({
-      where: {
-        x: {
-          gte: 0,
-          lt: this.getCanvasConfig().size[0],
-        },
-        y: {
-          gte: 0,
-          lt: this.getCanvasConfig().size[1],
-        },
-        isTop: true,
-      },
+      CanvasWorker.once("message", (msg) => {
+        if (msg.type === "canvasToRedis") {
+          Logger.info("Finished canvasToRedis()");
+          res(msg.data);
+        }
+      });
+
+      CanvasWorker.postMessage({
+        type: "canvasToRedis",
+        width,
+        height,
+      });
     });
-
-    const pixels: string[] = [];
-
-    // (y -> x) because of how the conversion needs to be done later
-    // if this is inverted, the map will flip when rebuilding the cache (5 minute expiry)
-    // fixes #24
-    for (let y = 0; y < this.canvasSize[1]; y++) {
-      for (let x = 0; x < this.canvasSize[0]; x++) {
-        pixels.push(
-          dbpixels.find((px) => px.x === x && px.y === y)?.color ||
-            "transparent"
-        );
-      }
-    }
-
-    await redis.set(Redis.key("canvas"), pixels.join(","), { EX: 60 * 5 });
-
-    Logger.info(
-      "Finished canvasToRedis in " +
-        ((Date.now() - now) / 1000).toFixed(2) +
-        "s"
-    );
-    return pixels;
   }
 
   /**
@@ -450,7 +430,7 @@ class Canvas {
     await redis_set.setEx(Redis.key("heatmap"), 60 * 5, heatmapStr);
 
     // notify anyone interested about the new heatmap
-    await redis_sub.publish(Redis.key("channel_heatmap"), heatmapStr);
+    await redis_set.publish(Redis.key("channel_heatmap"), heatmapStr);
     // SocketServer.instance.io.to("sub:heatmap").emit("heatmap", heatmapStr);
 
     return heatmapStr;

packages/server/src/lib/Logger.ts

@@ -36,6 +36,8 @@ export const LoggerType = createEnum([
   "REDIS",
   "SOCKET",
   "JOB_WORKER",
+  "CANVAS_WORK",
+  "WORKER_ROOT",
 ]);
 
 export const getLogger = (module?: keyof typeof LoggerType) =>

packages/server/src/workers/canvas.ts

@@ -0,0 +1,78 @@
+import { parentPort } from "node:worker_threads";
+import { Redis } from "../lib/redis";
+import { prisma } from "../lib/prisma";
+import { getLogger } from "../lib/Logger";
+
+type Message = {
+  type: "canvasToRedis";
+  width: number;
+  height: number;
+};
+
+const Logger = getLogger("CANVAS_WORK");
+
+/**
+ * We run the connection directly instead of via class functions to prevent side effects
+ */
+const redis = Redis.client;
+redis.connect().then(() => {
+  Logger.info("Connected to Redis");
+});
+
+parentPort?.on("message", (msg: Message) => {
+  switch (msg.type) {
+    case "canvasToRedis":
+      canvasToRedis(msg.width, msg.height).then((str) => {
+        parentPort?.postMessage({ type: "canvasToRedis", data: str });
+      });
+      break;
+  }
+});
+
+/**
+ * Convert database pixels to Redis cache
+ *
+ * This does not depend on the Canvas class and can be ran inside the worker
+ *
+ * @param width
+ * @param height
+ * @returns
+ */
+const canvasToRedis = async (width: number, height: number) => {
+  const now = Date.now();
+  Logger.info("Starting canvasToRedis...");
+
+  const dbpixels = await prisma.pixel.findMany({
+    where: {
+      x: {
+        gte: 0,
+        lt: width,
+      },
+      y: {
+        gte: 0,
+        lt: height,
+      },
+      isTop: true,
+    },
+  });
+
+  const pixels: string[] = [];
+
+  // (y -> x) because of how the conversion needs to be done later
+  // if this is inverted, the map will flip when rebuilding the cache (5 minute expiry)
+  // fixes #24
+  for (let y = 0; y < height; y++) {
+    for (let x = 0; x < width; x++) {
+      pixels.push(
+        dbpixels.find((px) => px.x === x && px.y === y)?.color || "transparent"
+      );
+    }
+  }
+
+  await redis.set(Redis.key("canvas"), pixels.join(","), { EX: 60 * 5 });
+
+  Logger.info(
+    "Finished canvasToRedis in " + ((Date.now() - now) / 1000).toFixed(2) + "s"
+  );
+  return pixels;
+};

packages/server/src/workers/worker.ts

@@ -0,0 +1,47 @@
+import { Worker, WorkerOptions } from "node:worker_threads";
+import path from "node:path";
+import { getLogger } from "../lib/Logger";
+
+const Logger = getLogger("WORKER_ROOT");
+
+export const spawnWorker = (file: string, wkOpts: WorkerOptions = {}) => {
+  if (process.env.NODE_ENV === "production") file = file.replace(".ts", ".js");
+
+  // https://github.com/TypeStrong/ts-node/issues/676#issuecomment-531620154
+  wkOpts.eval = true;
+  if (!wkOpts.workerData) {
+    wkOpts.workerData = {};
+  }
+  wkOpts.workerData.__filename = path.join(__dirname, file);
+  return new Worker(
+    `
+          const wk = require('worker_threads');
+          require('ts-node').register();
+          let file = wk.workerData.__filename;
+          delete wk.workerData.__filename;
+          require(file);
+      `,
+    wkOpts
+  );
+};
+
+const AllWorkers = {
+  canvas: spawnWorker("canvas.ts"),
+};
+
+export const CanvasWorker = AllWorkers.canvas;
+
+for (const [name, worker] of Object.entries(AllWorkers)) {
+  worker.on("online", () => {
+    Logger.info(`${name} worker is now online`);
+  });
+
+  worker.on("exit", (exitCode) => {
+    Logger.warn(`${name} worker has exited ${exitCode}`);
+  });
+
+  worker.on("error", (err) => {
+    Logger.warn(`${name} worker has errored ${err.message}`);
+    console.error(err);
+  });
+}