* user_lastaccess deleted when deleting course
* rewritten deleting of contexts - does not use get_context_instance() anymore because it is much more strict now
* added deleting of grade_letters and settings when deleting course
* improved handling of dirty contexts in general - caching, switching in cron, marking, loading, etc.
* role_assing() and role_unassign() now marks dirty contexts because we use has_capability() in this function - we can not do it later outside to speedup bulk operations
* fixed some inline docs
* fixed notice from rs closing
* removed cached $CONTEXT from has_capability() - $context is now required parameter; this was hiding serious bugs when context did not exist or ppl passed false as parameter
* removed some ===, we can not use these on function parameters - we must support ints, strings, '', nulls, etc. - this could be a source of really dangerous bugs in future
* some other improvements and fixes - documented inline
MDL-11527 fixed warning from $CFG->defaultuserroleid when installing and upgrading
+ removed reusing of previous contexts in has_capability() and get_context_instance() because it was hiding critical errors when context was false, not specified, etc.
+ tweaked roles defaults - faster and defaults are applied when roles exist
+ SYSCONTEXTID may be specified in config.php to eliminate 1 db query
+ static context cache is now reset after rebuilding of context paths
+ path field in context table is now nullable - pg compatibility requirement
+ other minor fixes
get_dirty_contexts() and mark_context_dirty() now use cache_flags
infrastructure. Remove deprecated cleanup_dirty_contexts() - this is
now handled by gc_cache_flags() in a more generic way.
new permanent context_temp table. Update for
Oracle added, extra NOT EXISTS cluse to avoid
insertion of duplicate records in potential
concurrency and minor refinements. MDL-11347
A bit of cleanup on the SQL we use for updates. Unfortunately, MySQL
uses non-SQL-standard syntax for updates reading or updating multiple
tables. After much testing across Pg and MySQL, I boiled it down to
the minimal differences -- but we still have different SQL.
The timings for this on a large reference install, calling
build_context_path(true):
- MySQL incompatible 1s
- Petr's fixes 60s -- DB complains of too many writes
- This commit 24s -- DB complains of too many writes
Also - fixed a remaining problem with $emptyclause
Affects MDL-11347
In one tiny patch we do two things.
First, we fix the race condition around dirty context and accessdata
timestamps -- it is saner to offset the check than to offset the
recording of the change (as an earlier patch did).
On a cluster, you still need NTP.
Second, we do away with CAST(). Ideally, the values should be compared
as ints but it's hard to get a CAST() syntax that is portable enough
to work on all our supported DBs. And Eloy pointed out (and I
corroborated testing) that we'll never have problems with the string
length, as our timestamps are always 10 chars as a string... and the
day they go to 11 chars we'll hit the unix Year-2038 bug.
Blocks not on the coursepage should have their context "hanging" from the
site context. get_context_instance() was doing this correctly, but not
build_context_path().
