This patch introduces a cookie cache in the WebContent process to reduce
blocking IPC calls when JS accesses document.cookie. The UI process now
maintains a cookie version counter per-domain in shared memory. When JS
reads document.cookie, we check whether we have a valid cached cookie by
comparing the current shared version to the last used version. If they
match, the cached cookie is returned without IPC.
This optimization is based on Chromium's shared versioning, in which it
was observed that 87% of document.cookie accesses were redundant. See:
https://blog.chromium.org/2024/06/introducing-shared-memory-versioning-to.html
Note that this cache only supports document.cookie, not HTTP Cookie
headers. HTTP cookies are attached to requests with varying URLs and
paths. The cookies that match the document URL might not match the
request URL, which we wouldn't know from WebContent. So attaching the
cached document cookie would be incorrect.
On https://twinings.co.uk, we see approximately 600 document.cookie
requests while the page loads. This patch reduces the time spent in
the document.cookie getter from ~45ms to 2-3ms.
When cookies change or expire, we currently send a list of all changed
cookies to all WebContent processes. We then filter that list in the
WebContent process for cookies that match the page's URL before sending
out cookie change events to JS.
We now perform this filtering in the UI process, so each WebContent
process only receives the cookies it would be interested in, if any.
This serves two purposes:
1. Less IPC chatter.
2. This will let each ViewImplementation know that its cookie value has
actually changed.
(2) is for an upcoming change that will introduce a cookie cache, and
will allow each view to know it should bust that cache.
Note that for this filtering to work, we must iterate ViewImplementation
instances rather than WebContentClient in order to have the view's URL.
We must then associate the IPC with the view's page ID.
No changes to the /cookiestore WPT subtests.
It currently lives in LibWebView as it was only used for cookies and
local storage, both of which are managed in the UI process. Let's move
it to its own library now to allow other processes to use it, without
having to depend on LibWebView (and therefore LibWeb).
The inspector widget has this functionality, but it's limited to the
site you're currently viewing. This commit adds an option for removing
all cookies globally.
Previously, the workaround was to open a sqlite shell and run:
`DELETE FROM Cookies;` on the database yourself.
C++ will jovially select the implicit conversion operator, even if it's
complete bogus, such as for unknown-size types or non-destructible
types. Therefore, all such conversions (which incur a copy) must
(unfortunately) be explicit so that non-copyable types continue to work.
NOTE: We make an exception for trivially copyable types, since they
are, well, trivially copyable.
Co-authored-by: kleines Filmröllchen <filmroellchen@serenityos.org>
