The largest of the 2 typo3 libs we ship in Moodle is never used. So
don't even parse it.
This takes Moodle's "default homepage" from 1.8MB to 1.6MB of PHP.
Tiny, but every bit helps...
If MDL_PERFINC is defined, we now print to errorlog a listing
of the files included, their size, and then a total size.
The total size isn't the most important metric, though it does give us
a good idea of how much PHP the PHP engine is parsing for us. The main
cost is still in the seeks involved.
Even when using precompilers -- our best-case scenario -- each include
or require forces at least 2 stat()s to compare timestamps in the php
file vs the precompiled file. If the working set fits in buffers we are
fine, but our 60+ stat() calls per page is quite a bit.
is_siteadmin checks a few key capabilities to suss out if the user is
an admin. The main virtue of the function is that it does not use
the accesslib infrastructure -- it reads directly from the DB, which
is useful for the 1.9 accesslib upgrade.
If we are passed an empty string for $order, still create valid
SQL. Some callers in 1.9 seem to not care about order, passing
an explicit ''. Shocking! ;-)
These references to the deprecated functions were erroring out. Remove
them.
Note however that other role related cleanups done as part of
MDL-10679 "improvement to context_rel table and load_user_capability()"
are kept.
We now populate the context.path only where it's empty,
this means that we take 0.15s instead of 0.6s. More importantly,
we avoid thrashing the DB's indexes pointlessly.
We also support Oracle and its dirty hack here.
And the function now has a $force parameter that can be used to
actually overwrite the paths/depths in case they've been corrupted.
get_assignable_roles() was calling user_can_assign() (cost of 1~2 DBq)
once-per-role. Instead, we can do a single DB query that answers
all our questions in one go.
On a Moodle w 8 roles defined, saves 19 DB queries for the course page
for teachers/admins.
NOTE NOTE NOTE! With this patch we drop the insane strip/escape bit.
Only the caller knows if this is for display on html or for other uses,
so we'll be true and not mangle the data.
A review of all callers in 1.8 shows no problem - the strings were being
strip/escaped already.
With this patch, get_categories() now adds a nice context
sub-object to the returned object, which means callers can
save DB traffic.
It now also supports "deep" retrievals, which means we can
rewrite the course categories display pages to avoid
costly recursion.
Don't update fields unnecessarily. Cuts 3 DB queries per category
on course/index page (45 in a 15 category setup).
fix_course_sortorder() should be fixed to avoid recursion.
For an efficient print_courses() we need to grab in a constant number
of queries...
- course data
- "course manager" role assignments
- user records for the coursemanagers' fullname()
So here we do it in 2 DB queries. The 2nd one (grabbing RAs and user
records) can be expensive if we are dealing with a large number of
courses.
Which we shouldn't - When the number of courses is large the course
listing doesn't come this way anyway...
When querying capabilities of non-logged-in users, has_capability()
will now load accessdata for the subcontexts as needed.
Without this patch, below-the-course RAs and rdefs were ignored when
checking caps for a user different from $USER. I don't think it is
ever done in current moodle code, so the problem wasn't visible.
In any case - it's fixed ;-)
A bit of rework around require_login()
- Fixed a subtle bug in the check whether a user can see sitecourse
hidden activities
- Save 1 DBq and 2 includes per call by only calling
get_auth_plugin() only when needed.
- Grab the contexts we are interested in only once and keep them in
variables.
Both of them are dead code in 18_STABLE and HEAD. And if
role_add_lastaccess_entries() is ever used on a large site it will
hammer the DB to bits.
Remove before anyone is foolish enough to try it.
We had a 1s race condition where a user could get their rights loaded
at the exact time an admin is changing roles/caps and see the "old"
data. Or even see a half-updated view of the access controls.
Yuck.
So we fix the race condition backdating the dirtyness. Cheap, but
effective. And then we backdate it some more to cover for minor clock
flutter on clusters (you still need ntp however!).
has_capability() can handle the fake user that forum cron sets up
and will load the appropriate accessdata into $USER->access.
This makes forum cron work again. A test comparison between before
this patchseries yields:
With 1 forum post, sent total 24 times
- Before 11 000 DB queries (approx)
- After 506 DB queries
With 6 forum posts, sent a total of 452 times
- Before 47 876 DB queries
- After 8 256 DB queries
There is a very high variability, but we are going from 100-500
queries per sent email to 18-21 queries per sent email. The
variability probably stems from 2 of the 6 posts being in a 200-user
forum.
Still huge - by the time we are sending the email, we should know
everything we need to know about the user, the forum/thread/post and
the form. The average should be well below 1 DB query per email sent!
print_user_picture() was forcing an unneeded dbquery
if you need an imagealt. And who doesn't need one these days.
So - teach print_user_picture() to take either $userid
_or_ $userobj as the first parameter. If that first
parameter has the fields we need, never touch the db.
In other words, only touch the DB as a last resort.
There is a bit of ugliness in testing whether we have
the fields or not, because these fields are inconsistently
with/without NOT NULL in the DB definitions. So we cannot
use isset() because it barfs on nulls. And we cannot use empty()
because it will match both on "missing key" and ''.
And while at it, silence warnings that we are missing string
for the year(s). Also fixes a missing string bug in really boring
courses that noone's visitied in many years ;-)
Reworked the logic of the visibility checks so that we evaluate in a
chain:
- can view course (visible or user can see hidden)
- can view category (visible or user can see hidden)
Without this patch, users that could see hidden categories could not get
into courses inside of them.
While at it, fix reference to the old $USER->switchrole
Reworked course_parent_visible() to always return in a constant
number of db queries (2 worst case) regardless of nesting depth.
The rewritten version has a small cache, but if you are going to
walk many courses, it's still 1~2 DB queries per category seen,
so the right thing to do is to check it in the caller, as seen
in get_my_courses().
Reworked gmc to perform the course visibility checks. These are
very cheap if $CFG->allowvisiblecoursesinhiddencategories is true.
However, where we have to enforce category visibility, it adds a bit
of work. In simple terms, it adds a DB query to read all the categories,
and extra checks to make sure we are doing the right thing WRT
- course visibility vs the permission to see hidden courses
- category visibility vs the permission to see hidden categories
and still do it quickly.
Costs next to nothing according to testing, and allows us to walk
the categories very cheaply. We'll need this in get_my_courses()...
What a cheapskates I am...
If you are a teacher in course X, you have at least
teacher-in-X + defaultloggedinuser-sitewide. So in the
course you'll have techer+defaultloggedinuser.
We try to mimic that in switchrole.
Thanks to Petr for pointing me to a similar fix in CVS.
Probably related: MDL-10945
We had quite a bit of leftover rdef and ra mangling.
Be more thorough and clear it up.
While at it, make load_user_accessdata() and load_all_capabilities()
more consistent.
