multithreading/src/lib/shared.js

The missing standard library for multithreading in JavaScript (Works in the browser, Node.js, Deno, Bun).

import { Transferable } from "./transferable.js";
export const toSerialized = Symbol("Thread.Serialize");
export const toDeserialized = Symbol("Thread.Deserialize");
export class Serializable {
    static [toDeserialized](_obj) {
        throw new Error(`[toDeserialized] not implemented for ${this.name}`);
    }
}
const classRegistry = new Map();
const reverseClassRegistry = new Map();
export function register(typeId, cls) {
    classRegistry.set(typeId, cls);
    reverseClassRegistry.set(cls, typeId);
}
export function serialize(arg) {
    // Null/Undefined
    if (arg === null || arg === undefined) {
        return [[0 /* PayloadType.RAW */, arg], []];
    }
    // Library Object (Instance of Serializable)
    if (typeof arg === "object" && arg !== null &&
        typeof arg[toSerialized] === "function") {
        const [value, transfer, typeId] = arg[toSerialized]();
        const Ctor = arg.constructor;
        return [[
                1 /* PayloadType.LIB */,
                value,
                typeId ?? reverseClassRegistry.get(Ctor),
            ], transfer ?? []];
    }
    // Transferables / Raw Data
    const transfer = [];
    if (arg instanceof SharedArrayBuffer) {
        // No-op
    }
    else if (ArrayBuffer.isView(arg)) {
        if (!(arg.buffer instanceof SharedArrayBuffer)) {
            transfer.push(arg.buffer);
        }
    }
    else if (arg instanceof Transferable) {
        transfer.push(arg);
    }
    return [[0 /* PayloadType.RAW */, arg], transfer];
}
export function deserialize(envelope) {
    if (!envelope || typeof envelope !== "object")
        return envelope;
    if (envelope[0] === 0 /* PayloadType.RAW */) {
        return envelope[1];
    }
    if (envelope[0] === 1 /* PayloadType.LIB */) {
        const Cls = classRegistry.get(envelope[2]);
        if (Cls) {
            return Cls[toDeserialized](envelope[1]);
        }
        throw new Error(`Unknown TypeID ${envelope[2]}. Did you forget to import the class?`);
    }
    return envelope;
}