When cache is disabled but temporary in-memory caches are allowed,
these were direct instances of cachestore_static with no loader, which
meant that the get_versioned and set_versioned functions did not work.
During install/upgrade, caching is disabled. This change provides a
way to temporarily enable caching (using in-memory cache storage only)
within a specific function; caches are deleted afterwards.
Adding this to two locations improves install performance quite a lot.
Caching is not enabled during the parts of plugin installation that
can vary for individual plugins (install.php/upgrade.php) as these
might be relying on its absence, for example by making direct database
changes.
Adds new set_versioned and get_versioned APIs to cache, which means you can
request a specific version from cache and it will not return an outdated
version.
This is important when using multi-layer-caches where a local cache might have
an outdated version of the cache, but the shared cache has a current version.
With this feature, the content of the cache does not have to be rebuilt, as
it will automatically retrieve it from the shared cache if necessary.
- count() can only be called on arrays or Countable, it can not be called on null
- recordset is neither so iterator_count() should be used
- instanceof or get_class() can not be applied to non-objects
- class methods must have the same arguments as methods in parent class
It is now safe to cache a reference to a cache and expect consistent results.
Changing identifiers altered cache results where a reference was
held to the cache. Identifiers have been set to be cached with
identifiers included so the caches are separate.
As a consequence of this it was identified that invalidation events
and identifiers don't easily work together as an event can't determine
which identifiers should be used for cache invalidation. So invalidation
events have been made incompatible with identifiers being set. No core
code used this combination as it's not possible to understand any expected
behaviour.
Event invalidation for application and session caches was centralised to the same
location. The only difference was the name of the lastinvalidation variable. This
improves support and consistency of invalidation code.
Cache data source aggregate functionality was found to be broken
and unused, because of this the decision was made to remove it
rather than fix it.
As it was broken we did not follow typical deprecation methods and
instead the code was removed outright with only structure
remaining and left deprecated.
The solution to this issue was to make the disabled cache factory
return a proper cache writer object when requested rather than a
disabled cache object.
This only changes things when CACHE_DISABLE_ALL has been defined.
