Drop cache

[annevk]

As discussed in privacycg/storage-partitioning#11 it's complicated already and in a partitioned future even less desirable. There's also very little advocacy in favor of it that I've heard raising this topic with people. Folks primarily care about storage (and that clearing all of it, including service workers and such).

We'll likely do this in Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1671182.

[annevk]

Update: Firefox dropped support for this as discussed.

[o-t-w]

From a developer point of view the status of all of this is now a bit confusing.

• Firefox purposefully removed support for "cache"
• Chrome/Edge does support "cache" and clears all caches
• Safari Technology Preview does support "cache" but only clears bfcache?

Do I have that right?

[miketaylr]

• Safari Technology Preview does support "cache" but only clears bfcache?

I haven't done any testing on TP, but I did see they just added support for CSD in these two commits:

WebKit/WebKit@c65efd2
WebKit/WebKit@5e99c8f

Given WebKit/WebKit@c65efd2#diff-f978e2275336c983f36efd6d218fe5bd8c7d3f4aa9932618470bc6c73762ea99R396, I would expect it to not just be restricted to bfcache.

[cdumez]

• Safari Technology Preview does support "cache" but only clears bfcache?

I haven't done any testing on TP, but I did see they just added support for CSD in these two commits:

WebKit/WebKit@c65efd2 WebKit/WebKit@5e99c8f

Given WebKit/WebKit@c65efd2#diff-f978e2275336c983f36efd6d218fe5bd8c7d3f4aa9932618470bc6c73762ea99R396, I would expect it to not just be restricted to bfcache.

Correct. Unless there is a bug, my intention when implementing this was that cache would clear both the HTTP disk cache AND the bfcache in WebKit.