readmongo/node_modules/terser-webpack-plugin/dist/TaskRunner.js

"use strict";

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

var _os = _interopRequireDefault(require("os"));

var _pLimit = _interopRequireDefault(require("p-limit"));

var _jestWorker = _interopRequireDefault(require("jest-worker"));

var _serializeJavascript = _interopRequireDefault(require("serialize-javascript"));

var _minify = _interopRequireDefault(require("./minify"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

const workerPath = require.resolve('./worker');

class TaskRunner {
  constructor(options = {}) {
    this.taskGenerator = options.taskGenerator;
    this.files = options.files;
    this.cache = options.cache;
    this.availableNumberOfCores = TaskRunner.getAvailableNumberOfCores(options.parallel);
  }

  static getAvailableNumberOfCores(parallel) {
    // In some cases cpus() returns undefined
    // https://github.com/nodejs/node/issues/19022
    const cpus = _os.default.cpus() || {
      length: 1
    };
    return parallel === true ? cpus.length - 1 : Math.min(Number(parallel) || 0, cpus.length - 1);
  }

  async runTask(task) {
    if (this.worker) {
      return this.worker.transform((0, _serializeJavascript.default)(task));
    }

    return (0, _minify.default)(task);
  }

  async run() {
    const {
      availableNumberOfCores,
      cache,
      files,
      taskGenerator
    } = this;
    let concurrency = Infinity;

    if (availableNumberOfCores > 0) {
      // Do not create unnecessary workers when the number of files is less than the available cores, it saves memory
      const numWorkers = Math.min(files.length, availableNumberOfCores);
      concurrency = numWorkers;
      this.worker = new _jestWorker.default(workerPath, {
        numWorkers
      }); // https://github.com/facebook/jest/issues/8872#issuecomment-524822081

      const workerStdout = this.worker.getStdout();

      if (workerStdout) {
        workerStdout.on('data', chunk => {
          return process.stdout.write(chunk);
        });
      }

      const workerStderr = this.worker.getStderr();

      if (workerStderr) {
        workerStderr.on('data', chunk => {
          return process.stderr.write(chunk);
        });
      }
    }

    const limit = (0, _pLimit.default)(concurrency);
    const scheduledTasks = [];

    for (const file of files) {
      const enqueue = async task => {
        let taskResult;

        try {
          taskResult = await this.runTask(task);
        } catch (error) {
          taskResult = {
            error
          };
        }

        if (cache.isEnabled() && !taskResult.error) {
          taskResult = await cache.store(task, taskResult).then(() => taskResult, () => taskResult);
        }

        task.callback(taskResult);
        return taskResult;
      };

      scheduledTasks.push(limit(() => {
        const task = taskGenerator(file).next().value;

        if (!task) {
          // Something went wrong, for example the `cacheKeys` option throw an error
          return Promise.resolve();
        }

        if (cache.isEnabled()) {
          return cache.get(task).then(taskResult => task.callback(taskResult), () => enqueue(task));
        }

        return enqueue(task);
      }));
    }

    return Promise.all(scheduledTasks);
  }

  async exit() {
    if (!this.worker) {
      return Promise.resolve();
    }

    return this.worker.end();
  }

}

exports.default = TaskRunner;