forked from mirrors/gecko-dev
ae619c5049
This goes through the previous changes in the dependencies of bug 877389, and does two things: 1) Remove instances of \n 2) Change reporting of exceptions so that they are passed as separate arguments. This should result in an improved display of the exception in the browser console, should it occur. Differential Revision: https://phabricator.services.mozilla.com/D180843
90 lines
2.5 KiB
JavaScript
90 lines
2.5 KiB
JavaScript
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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/**
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* A file (disk) based persistent cache of a JSON serializable object.
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*/
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export class PersistentCache {
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/**
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* Create a cache object based on a name.
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*
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* @param {string} name Name of the cache. It will be used to create the filename.
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* @param {boolean} preload (optional). Whether the cache should be preloaded from file. Defaults to false.
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*/
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constructor(name, preload = false) {
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this.name = name;
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this._filename = `activity-stream.${name}.json`;
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if (preload) {
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this._load();
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}
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}
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/**
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* Set a value to be cached with the specified key.
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*
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* @param {string} key The cache key.
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* @param {object} value The data to be cached.
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*/
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async set(key, value) {
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const data = await this._load();
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data[key] = value;
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await this._persist(data);
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}
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/**
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* Get a value from the cache.
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*
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* @param {string} key (optional) The cache key. If not provided, we return the full cache.
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* @returns {object} The cached data.
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*/
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async get(key) {
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const data = await this._load();
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return key ? data[key] : data;
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}
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/**
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* Load the cache into memory if it isn't already.
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*/
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_load() {
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return (
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this._cache ||
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// eslint-disable-next-line no-async-promise-executor
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(this._cache = new Promise(async (resolve, reject) => {
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let filepath;
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try {
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filepath = PathUtils.join(PathUtils.localProfileDir, this._filename);
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} catch (error) {
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reject(error);
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return;
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}
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let data = {};
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try {
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data = await IOUtils.readJSON(filepath);
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} catch (error) {
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if (
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// isInstance() is not available in node unit test. It should be safe to use instanceof as it's directly from IOUtils.
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// eslint-disable-next-line mozilla/use-isInstance
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!(error instanceof DOMException) ||
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error.name !== "NotFoundError"
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) {
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console.error(`Failed to parse ${this._filename}:`, error.message);
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}
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}
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resolve(data);
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}))
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);
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}
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/**
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* Persist the cache to file.
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*/
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async _persist(data) {
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const filepath = PathUtils.join(PathUtils.localProfileDir, this._filename);
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await IOUtils.writeJSON(filepath, data, {
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tmpPath: `${filepath}.tmp`,
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});
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}
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}
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