modmapper-web/lib/WorkerPool.ts
Tyler Hallada 38d3536340 Create workers using new webpack 5 syntax
Drop worker-loader which isn't needed anymore.
2022-03-19 01:15:25 -04:00

84 lines
2.4 KiB
TypeScript

import { createContext } from "react";
import {
addPluginInOrder,
decrementPending,
PluginFile,
} from "../slices/plugins";
import store from "./store";
export interface Task {
skipParsing: boolean,
filename: string,
lastModified: number,
contents: Uint8Array,
}
export class WorkerPool {
public taskQueue: Task[];
public availableWorkers: Worker[];
public constructor() {
this.taskQueue = [];
this.availableWorkers = [];
}
public async init(count: number = window.navigator.hardwareConcurrency ?? 8): Promise<WorkerPool> {
this.availableWorkers = [];
for (let i = 0; i < count; i++) {
this.availableWorkers.push(await this.createWorker());
}
return this;
}
public async addWorker() {
const worker = await this.createWorker();
this.availableWorkers.push(worker);
this.assignWorker();
}
public async createWorker(): Promise<Worker> {
return new Promise((resolve) => {
const worker = new Worker(new URL("../workers/PluginsLoader.worker.ts", import.meta.url));
worker.onmessage = (evt: {
data: string | PluginFile;
}) => {
const { data } = evt;
if (typeof data === "string" && data === "ready") {
resolve(worker);
} else if (typeof data !== "string") {
store.dispatch(decrementPending(1));
store.dispatch(addPluginInOrder(data));
// Since web assembly memory cannot be shrunk, replace worker with a fresh one to avoid slow repeated
// invocations on the same worker instance. Repeated invocations are so slow that the delay in creating a
// new worker is worth it. In practice, there are usually more workers than tasks, so the delay does not slow
// down processing.
worker.terminate();
this.addWorker();
}
};
});
}
public pushTask(task: Task) {
this.taskQueue.push(task);
this.assignWorker();
}
public async assignWorker() {
if (this.taskQueue.length > 0 && this.availableWorkers.length > 0) {
const task = this.taskQueue.shift()!;
const worker = this.availableWorkers.shift()!;
worker.postMessage(task, [task.contents.buffer]);
}
}
public async terminateAll() {
for (const worker of this.availableWorkers) {
worker.terminate();
}
this.availableWorkers = [];
}
}
export const WorkerPoolContext = createContext<WorkerPool | null>(null);