up the documentation a little.
chx: can you double-check whether the global $conf variable is secure?
(That is, make sure it can't be send using the URL or something.)
keep track of the user's last access. In turn, this allowed me to:
1. Optimize the "Who's online" block. On drupal.org, the "Who's online"
block requires 32 SQL queries. With this patch, only 2 queries are
left (eliminated 30 SQL queries), and one of the two remaining queries
became appr. 20 times faster.
2. Correct the "Last access" column in the user administration overview
table. The presented data was not accurate, which led to the column
being removed. You can now sort users by 'last access'.
Drupal's existing caching mechanism doesn't perform well on highly dynamic websites in which the cache is flushed frequently. One example is a site that is under attack by a spambot that is posting spam comments every few seconds, causing all cached pages to be flushed every few seconds. Loose caching immediately flushes the cache only for specific users who have modified cached data (whether or not they are logged in), delaying the flushing of data for other users by several minutes.
(I rewrote the help text a bit and made minor changes to the code comments.)
That should improve performance of session handling as well improve
performance of the "Who's online"-block. Drupal.org's sessions table
contains appr. 40.000 sessions on a slow day and rendering the "Who's
online"-block became a performance bottleneck.
This change has yet to be tested on a busy site so things might go wrong.
Dries Buytaert
Steven Wittens
Kjartan Mannes