Updated mediawiki/extensions Project: mediawiki/extensions/Flow…


Updated mediawiki/extensions Project: mediawiki/extensions/Flow 645a6ecae6209b71bcbe52b8f3a8fb35e85ae010

Fix topic history's revision cache expansion

Cache indices try to store as little data as possible. For a list of
things (like history), it tries to only store an array of IDs in one
cache key, then store all data per entry in separate cache keys. This
should prevent huge cache entries & lots of duplicated data.

That also means that, when you do want to load that data, you just
get the IDs of the entries and have to expand those (load the real
data associated with those IDs)

As you'll see in container.php, the topic history index
(storage.topic_history.indexes.topic_lookup) defines shallow compactor
storage.topic_history.indexes.primary, which means it'll compact/expand
based on the primary key defined there: rev_id.
To expand those entries, it'll query that same index, for rev_id.

That index's retrieval method (findMulti) assumed it would only ever
be called with queries in the form of 'topic_root_id' = ... (which is
how we request data for a particular topic) - it didn't consider that
it would also be called to expand those revisions.

There already was a method findDescendants that queried posts &
summary after it had determined the tree of things inside a topic. I'm
now also accepting more than 'topic_root_id' input & relaying it to
that method. Does the trick!

Meanwhile, I also noticed that the safeguard to not let invalid data
(e.g. missing content from ExternalStore) be cached was incorrect: it
would still cache data if in that same index, other entries are valid.
Instead: it shouldn't cache if anything in there is invalid.

Bug: T103053
Change-Id: Ib92fc4549e8187aef38fbe6f5c87521d336c278b


jenkins-botAuthored on
Gerrit Code Review <gerrit@wikimedia.org>Committed on Jun 25 2015, 11:04 PM
rMEXTaefe7de9b738: Updated mediawiki/extensions Project…

Event Timeline

Gerrit Code Review <gerrit@wikimedia.org> committed rMEXT6fe869d441a2: Updated mediawiki/extensions Project: mediawiki/extensions/Flow… (authored by jenkins-bot <jenkins-bot@gerrit.wikimedia.org>).Jun 25 2015, 11:04 PM