evnty/build/sequence.js

Async-first, reactive event handling library for complex event flows in browser and Node.js

import { Async } from "./async.js";
import { Signal } from "./signal.js";
import { RingBuffer } from "./ring-buffer.js";
export class Sequence extends Async {
    #queue;
    #nextSignal;
    #sendSignal;
    [Symbol.toStringTag] = 'Sequence';
    static merge(target, ...sequences) {
        for (const source of sequences){
            queueMicrotask(async ()=>{
                if (!target.disposed) try {
                    const sink = target.sink;
                    for await (const value of source){
                        if (!sink(value)) {
                            return;
                        }
                    }
                } catch  {}
            });
        }
    }
    constructor(abortSignal){
        super(abortSignal);
        this.#queue = new RingBuffer();
        this.#nextSignal = new Signal(abortSignal);
        this.#sendSignal = new Signal(abortSignal);
    }
    get size() {
        return this.#queue.length;
    }
    async reserve(capacity) {
        while(this.#queue.length > capacity){
            await this.#sendSignal;
        }
    }
    emit(value) {
        const ok = !this.disposed;
        if (ok) {
            this.#queue.push(value);
        }
        this.#nextSignal.emit();
        return ok;
    }
    async receive() {
        while(!this.#queue.length){
            await this.#nextSignal;
        }
        this.#sendSignal.emit();
        return this.#queue.shift();
    }
    dispose() {
        this.#sendSignal[Symbol.dispose]();
        this.#nextSignal[Symbol.dispose]();
    }
}

//# sourceMappingURL=sequence.js.map