gecko-dev/browser/components/sessionstore/test/browser_sessionStorage.js
David Rajchenbach-Teller d9df20222c Bug 1216250 - Limit amount of DOM Storage data stored by Session Restore. r=ttaubert
DOM Storage is a pretty inefficient and memory-hungry storage mechanism. Session Store attempts to record DOM Storage for each tab, which leads to (possibly very large) objects being serialized once to be sent from frame/content to parent and once to be sent from the main thread to the I/O thread. This is a suspect behind a number of crashes (see bug 1106264 for a discussion on the topic).

This patch limits the amount of DOM Storage that Session Restore attempts to store. We perform a quick estimate on the amount of memory needed to serialize DOM Storage and prevent storage larger than ~10M chars being sent from frame/content to the parent. Once this patch has landed, we will need to watch FX_SESSION_RESTORE_DOM_STORAGE_SIZE_ESTIMATE_CHARS to find out whether our threshold is meaningful.

--HG--
extra : transplant_source : %26%07%ADzjT%A9%E3%B9%B9%EC%9D%97n%23%B5%F2%DAZ%CD
2015-10-20 14:15:17 +02:00

229 lines
8.5 KiB
JavaScript

/* Any copyright is dedicated to the Public Domain.
* http://creativecommons.org/publicdomain/zero/1.0/ */
"use strict";
const RAND = Math.random();
const URL = "http://mochi.test:8888/browser/" +
"browser/components/sessionstore/test/browser_sessionStorage.html" +
"?" + RAND;
const OUTER_VALUE = "outer-value-" + RAND;
const INNER_VALUE = "inner-value-" + RAND;
/**
* This test ensures that setting, modifying and restoring sessionStorage data
* works as expected.
*/
add_task(function session_storage() {
let tab = gBrowser.addTab(URL);
let browser = tab.linkedBrowser;
yield promiseBrowserLoaded(browser);
// Flush to make sure chrome received all data.
yield TabStateFlusher.flush(browser);
let {storage} = JSON.parse(ss.getTabState(tab));
is(storage["http://example.com"].test, INNER_VALUE,
"sessionStorage data for example.com has been serialized correctly");
is(storage["http://mochi.test:8888"].test, OUTER_VALUE,
"sessionStorage data for mochi.test has been serialized correctly");
// Ensure that modifying sessionStore values works for the inner frame only.
yield modifySessionStorage(browser, {test: "modified1"}, {frameIndex: 0});
yield TabStateFlusher.flush(browser);
({storage} = JSON.parse(ss.getTabState(tab)));
is(storage["http://example.com"].test, "modified1",
"sessionStorage data for example.com has been serialized correctly");
is(storage["http://mochi.test:8888"].test, OUTER_VALUE,
"sessionStorage data for mochi.test has been serialized correctly");
// Ensure that modifying sessionStore values works for both frames.
yield modifySessionStorage(browser, {test: "modified"});
yield modifySessionStorage(browser, {test: "modified2"}, {frameIndex: 0});
yield TabStateFlusher.flush(browser);
({storage} = JSON.parse(ss.getTabState(tab)));
is(storage["http://example.com"].test, "modified2",
"sessionStorage data for example.com has been serialized correctly");
is(storage["http://mochi.test:8888"].test, "modified",
"sessionStorage data for mochi.test has been serialized correctly");
// Test that duplicating a tab works.
let tab2 = gBrowser.duplicateTab(tab);
let browser2 = tab2.linkedBrowser;
yield promiseTabRestored(tab2);
// Flush to make sure chrome received all data.
yield TabStateFlusher.flush(browser2);
({storage} = JSON.parse(ss.getTabState(tab2)));
is(storage["http://example.com"].test, "modified2",
"sessionStorage data for example.com has been duplicated correctly");
is(storage["http://mochi.test:8888"].test, "modified",
"sessionStorage data for mochi.test has been duplicated correctly");
// Ensure that the content script retains restored data
// (by e.g. duplicateTab) and sends it along with new data.
yield modifySessionStorage(browser2, {test: "modified3"});
yield TabStateFlusher.flush(browser2);
({storage} = JSON.parse(ss.getTabState(tab2)));
is(storage["http://example.com"].test, "modified2",
"sessionStorage data for example.com has been duplicated correctly");
is(storage["http://mochi.test:8888"].test, "modified3",
"sessionStorage data for mochi.test has been duplicated correctly");
// Check that loading a new URL discards data.
browser2.loadURI("http://mochi.test:8888/");
yield promiseBrowserLoaded(browser2);
yield TabStateFlusher.flush(browser2);
({storage} = JSON.parse(ss.getTabState(tab2)));
is(storage["http://mochi.test:8888"].test, "modified3",
"navigating retains correct storage data");
ok(!storage["http://example.com"], "storage data was discarded");
// Check that loading a new URL discards data.
browser2.loadURI("about:mozilla");
yield promiseBrowserLoaded(browser2);
yield TabStateFlusher.flush(browser2);
let state = JSON.parse(ss.getTabState(tab2));
ok(!state.hasOwnProperty("storage"), "storage data was discarded");
// Clean up.
yield promiseRemoveTab(tab);
yield promiseRemoveTab(tab2);
});
/**
* This test ensures that purging domain data also purges data from the
* sessionStorage data collected for tabs.
*/
add_task(function purge_domain() {
let tab = gBrowser.addTab(URL);
let browser = tab.linkedBrowser;
yield promiseBrowserLoaded(browser);
// Purge data for "mochi.test".
yield purgeDomainData(browser, "mochi.test");
// Flush to make sure chrome received all data.
yield TabStateFlusher.flush(browser);
let {storage} = JSON.parse(ss.getTabState(tab));
ok(!storage["http://mochi.test:8888"],
"sessionStorage data for mochi.test has been purged");
is(storage["http://example.com"].test, INNER_VALUE,
"sessionStorage data for example.com has been preserved");
yield promiseRemoveTab(tab);
});
/**
* This test ensures that collecting sessionStorage data respects the privacy
* levels as set by the user.
*/
add_task(function respect_privacy_level() {
let tab = gBrowser.addTab(URL + "&secure");
yield promiseBrowserLoaded(tab.linkedBrowser);
yield promiseRemoveTab(tab);
let [{state: {storage}}] = JSON.parse(ss.getClosedTabData(window));
is(storage["http://mochi.test:8888"].test, OUTER_VALUE,
"http sessionStorage data has been saved");
is(storage["https://example.com"].test, INNER_VALUE,
"https sessionStorage data has been saved");
// Disable saving data for encrypted sites.
Services.prefs.setIntPref("browser.sessionstore.privacy_level", 1);
tab = gBrowser.addTab(URL + "&secure");
yield promiseBrowserLoaded(tab.linkedBrowser);
yield promiseRemoveTab(tab);
[{state: {storage}}] = JSON.parse(ss.getClosedTabData(window));
is(storage["http://mochi.test:8888"].test, OUTER_VALUE,
"http sessionStorage data has been saved");
ok(!storage["https://example.com"],
"https sessionStorage data has *not* been saved");
// Disable saving data for any site.
Services.prefs.setIntPref("browser.sessionstore.privacy_level", 2);
// Check that duplicating a tab copies all private data.
tab = gBrowser.addTab(URL + "&secure");
yield promiseBrowserLoaded(tab.linkedBrowser);
let tab2 = gBrowser.duplicateTab(tab);
yield promiseTabRestored(tab2);
yield promiseRemoveTab(tab);
// With privacy_level=2 the |tab| shouldn't have any sessionStorage data.
[{state: {storage}}] = JSON.parse(ss.getClosedTabData(window));
ok(!storage, "sessionStorage data has *not* been saved");
// Remove all closed tabs before continuing with the next test.
// As Date.now() isn't monotonic we might sometimes check
// the wrong closedTabData entry.
while (ss.getClosedTabCount(window) > 0) {
ss.forgetClosedTab(window, 0);
}
// Restore the default privacy level and close the duplicated tab.
Services.prefs.clearUserPref("browser.sessionstore.privacy_level");
yield promiseRemoveTab(tab2);
// With privacy_level=0 the duplicated |tab2| should persist all data.
[{state: {storage}}] = JSON.parse(ss.getClosedTabData(window));
is(storage["http://mochi.test:8888"].test, OUTER_VALUE,
"http sessionStorage data has been saved");
is(storage["https://example.com"].test, INNER_VALUE,
"https sessionStorage data has been saved");
});
// Test that we record the size of messages.
add_task(function* test_telemetry() {
Services.telemetry.canRecordExtended = true;
let histogram = Services.telemetry.getHistogramById("FX_SESSION_RESTORE_DOM_STORAGE_SIZE_ESTIMATE_CHARS");
let snap1 = histogram.snapshot();
let tab = gBrowser.addTab(URL);
let browser = tab.linkedBrowser;
yield promiseBrowserLoaded(browser);
// Flush to make sure chrome received all data.
yield TabStateFlusher.flush(browser);
let snap2 = histogram.snapshot();
Assert.ok(snap2.counts[5] > snap1.counts[5]);
yield promiseRemoveTab(tab);
Services.telemetry.canRecordExtended = false;
});
// Lower the size limit for DOM Storage content. Check that DOM Storage
// is not updated, but that other things remain updated.
add_task(function* test_large_content() {
Services.prefs.setIntPref("browser.sessionstore.dom_storage_limit", 5);
let tab = gBrowser.addTab(URL);
let browser = tab.linkedBrowser;
yield promiseBrowserLoaded(browser);
// Flush to make sure chrome received all data.
yield TabStateFlusher.flush(browser);
let state = JSON.parse(ss.getTabState(tab));
info(JSON.stringify(state, null, "\t"));
Assert.equal(state.storage, null, "We have no storage for the tab");
Assert.equal(state.entries[0].title, OUTER_VALUE);
yield promiseRemoveTab(tab);
Services.prefs.clearUserPref("browser.sessionstore.dom_storage_limit");
});
function purgeDomainData(browser, domain) {
return sendMessage(browser, "ss-test:purgeDomainData", domain);
}