typed-utilities/build/AsyncSemaphore.js

Strongly typed general purpose utilities

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.AsyncSemaphore = void 0;

class AsyncSemaphore {
  constructor(max) {
    this.max = max;
    this._current = 0;
    this.queue = [];
  }

  run = async fn => {
    this._current++;

    try {
      return await fn();
    } finally {
      this._current--;
      this.trigger();
    }
  };
  trigger = () => {
    const next = this.queue.pop();

    if (next) {
      next();
    }
  };
  use = async fn => {
    if (this._current < this.max) {
      return await this.run(fn);
    }

    return await new Promise(resolve => {
      this.queue.push(resolve);
    }).then(() => this.run(fn));
  };

  get current() {
    return this._current;
  }

  get length() {
    return this.queue.length;
  }

}

exports.AsyncSemaphore = AsyncSemaphore;
//# sourceMappingURL=AsyncSemaphore.js.map