site-nodes cache reform: use ns_urlsspace instead of brute-force caching.
For OpenACS site with recent versions of NaviServer and XOTcl2,
cache sitenode information much more efficiently by the built-in
URL trie, which supports tree match operations, for
tree information. This means that for example for .vuh
handlers it is not necessary to cache the full url for
obtaining the site-node, like it was until now:
3839 id-/storage/view/installers/windows-installer/installer.htm
3839 id-/storage/view/aolserver/install.tgz
3839 id-/storage/view/tutorial/OpenACS_Tutorial.htm
3839 id-/storage/view/openacs-dotlrn-conference-2007-spring/Methodology_ALPE.pdf
3839 id-/storage/view/xowiki-resources/Assessment.jpg
3839 id-/storage/view/tutorial-page-map.png
...
Providing a single entry like
ns_urlspace set -key sitenode /storage/* 3839
is sufficient.
Why is this needed: current cache sizes of larger sites show 330K
(site A) and 390K (site B) cache entries. Matchbase flushes have to
gor thhrough all these entries, causing long lock times. Running
thhis code at OpenACS.org shows an improvement by a factor of more
than 200x.
