gecko-dev/dom/quota/test/common/content.js

63 строки
2.2 KiB
JavaScript

/**
* Any copyright is dedicated to the Public Domain.
* http://creativecommons.org/publicdomain/zero/1.0/
*/
const NS_ERROR_STORAGE_BUSY = SpecialPowers.Cr.NS_ERROR_STORAGE_BUSY;
loadScript("dom/quota/test/common/global.js");
function clearAllDatabases(callback) {
let qms = SpecialPowers.Services.qms;
let principal = SpecialPowers.wrap(document).nodePrincipal;
let request = qms.clearStoragesForPrincipal(principal);
let cb = SpecialPowers.wrapCallback(callback);
request.callback = cb;
return request;
}
// SimpleDB connections and SpecialPowers wrapping:
//
// SpecialPowers provides a SpecialPowersHandler Proxy mechanism that lets our
// content-privileged code borrow its chrome-privileged principal to access
// things we shouldn't be able to access. The proxies wrap their returned
// values, so once we have something wrapped we can rely on returned objects
// being wrapped as well. The proxy will also automatically unwrap wrapped
// arguments we pass in. However, we need to invoke wrapCallback on callback
// functions so that the arguments they receive will be wrapped because the
// proxy does not automatically wrap content-privileged functions.
//
// Our use of (wrapped) SpecialPowers.Cc results in getSimpleDatabase()
// producing a wrapped nsISDBConnection instance. The nsISDBResult instances
// exposed on the (wrapped) nsISDBRequest are also wrapped.
// In particular, the wrapper takes responsibility for automatically cloning
// the ArrayBuffer returned by nsISDBResult.getAsArrayBuffer into the content
// compartment (rather than wrapping it) so that constructing a Uint8Array
// from it will succeed.
function getSimpleDatabase() {
let connection = SpecialPowers.Cc[
"@mozilla.org/dom/sdb-connection;1"
].createInstance(SpecialPowers.Ci.nsISDBConnection);
let principal = SpecialPowers.wrap(document).nodePrincipal;
connection.init(principal);
return connection;
}
async function requestFinished(request) {
await new Promise(function (resolve) {
request.callback = SpecialPowers.wrapCallback(function () {
resolve();
});
});
if (request.resultCode != SpecialPowers.Cr.NS_OK) {
throw new RequestError(request.resultCode, request.resultName);
}
return request.result;
}