gecko-dev/services/settings/SharedUtils.jsm

54 строки
1.8 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Common logic shared by RemoteSettingsWorker.js (Worker) and the main thread.
*/
var EXPORTED_SYMBOLS = ["SharedUtils"];
var SharedUtils = {
/**
* Check that the specified content matches the expected size and SHA-256 hash.
* @param {ArrayBuffer} buffer binary content
* @param {Number} size expected file size
* @param {String} size expected file SHA-256 as hex string
* @returns {boolean}
*/
async checkContentHash(buffer, size, hash) {
const bytes = new Uint8Array(buffer);
// Has expected size? (saves computing hash)
if (bytes.length !== size) {
return false;
}
// Has expected content?
const hashBuffer = await crypto.subtle.digest("SHA-256", bytes);
const hashBytes = new Uint8Array(hashBuffer);
const toHex = b => b.toString(16).padStart(2, "0");
const hashStr = Array.from(hashBytes, toHex).join("");
return hashStr == hash;
},
/**
* Load (from disk) the JSON file distributed with the release for this collection.
* @param {String} bucket
* @param {String} collection
*/
async loadJSONDump(bucket, collection) {
// When using the preview bucket, we still want to load the main dump.
// But we store it locally in the preview bucket.
const jsonBucket = bucket.replace("-preview", "");
const fileURI = `resource://app/defaults/settings/${jsonBucket}/${collection}.json`;
let response;
try {
response = await fetch(fileURI);
} catch (e) {
// Return null if file is missing.
return { data: null, timestamp: null };
}
// Will throw if JSON is invalid.
return response.json();
},
};