lib/amd/src/local/process_monitor/processqueue.js

  1. // This file is part of Moodle - http://moodle.org/
  2. //
  3. // Moodle is free software: you can redistribute it and/or modify
  4. // it under the terms of the GNU General Public License as published by
  5. // the Free Software Foundation, either version 3 of the License, or
  6. // (at your option) any later version.
  7. //
  8. // Moodle is distributed in the hope that it will be useful,
  9. // but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11. // GNU General Public License for more details.
  12. //
  13. // You should have received a copy of the GNU General Public License
  14. // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16. import {debounce} from 'core/utils';
  17. import {LoadingProcess} from 'core/local/process_monitor/loadingprocess';
  18. import log from 'core/log';
  20. const TOASTSTIMER = 3000;
  22. /**
  23.  * A process queue manager.
  24.  *
  25.  * Adding process to the queue will guarante process are executed in sequence.
  26.  *
  27.  * @module     core/local/process_monitor/processqueue
  28.  * @class      ProcessQueue
  29.  * @copyright  2022 Ferran Recio <ferran@moodle.com>
  30.  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  31.  */
  32. export class ProcessQueue {
  33.     /** @var {Array} pending the pending queue. */
  34.     pending = [];
  36.     /** @var {LoadingProcess} current the current uploading process. */
  37.     currentProcess = null;
  39.     /**
  40.      * Class constructor.
  41.      * @param {ProcessMonitorManager} manager the monitor manager
  42.      */
  43.     constructor(manager) {
  44.         this.manager = manager;
  45.         this.cleanFinishedProcesses = debounce(
  46.             () => manager.dispatch('cleanFinishedProcesses'),
  47.             TOASTSTIMER
  48.         );
  49.     }
  51.     /**
  52.      * Adds a new pending upload to the queue.
  53.      * @param {String} processName the process name
  54.      * @param {Function} processor the execution function
  55.      */
  56.     addPending(processName, processor) {
  57.         const process = new LoadingProcess(this.manager, {name: processName});
  58.         process.setExtraData({
  59.             processor,
  60.         });
  61.         process.onFinish((uploadedFile) => {
  62.             if (this.currentProcess?.id !== uploadedFile.id) {
  63.                 return;
  64.             }
  65.             this._discardCurrent();
  66.         });
  67.         this.pending.push(process);
  68.         this._continueProcessing();
  69.     }
  71.     /**
  72.      * Adds a new pending upload to the queue.
  73.      * @param {String} processName the file info
  74.      * @param {String} errorMessage the file processor
  75.      */
  76.     addError(processName, errorMessage) {
  77.         const process = new LoadingProcess(this.manager, {name: processName});
  78.         process.setError(errorMessage);
  79.     }
  81.     /**
  82.      * Discard the current process and execute the next one if any.
  83.      */
  84.     _discardCurrent() {
  85.         if (this.currentProcess) {
  86.             this.currentProcess = null;
  87.         }
  88.         this.cleanFinishedProcesses();
  89.         this._continueProcessing();
  90.     }
  92.     /**
  93.      * Return the current file uploader.
  94.      * @return {FileUploader}
  95.      */
  96.     _currentProcessor() {
  97.         return this.currentProcess.data.processor;
  98.     }
  100.     /**
  101.      * Continue the queue processing if no current process is defined.
  102.      */
  103.     async _continueProcessing() {
  104.         if (this.currentProcess !== null || this.pending.length === 0) {
  105.             return;
  106.         }
  107.         this.currentProcess = this.pending.shift();
  108.         try {
  109.             const processor = this._currentProcessor();
  110.             await processor(this.currentProcess);
  111.         } catch (error) {
  112.             this.currentProcess.setError(error.message);
  113.             log.error(error);
  114.         }
  115.     }
  116. }