Static cache for taxonomy_get_parents and taxonomy_get_children

The static variables should be named for what they store, instead of $cache.

This should go into 6.x andthen be backported if necessary.

I tested a cached version of taxonomy_get_parents on Drupal 5 and Ubercart's catalog block benefits a lot from it. I'm sure similar taxonomy based menu structures will to. I agree that an optimization such as this one would be worth backporting to 5.x.

However, I not sure why the static variable needs protection?

The problem with this patch is that it also can break the API; when you do 'get - alter - save - get' you'll get an old copy of the data, not the updated version. This might be a little tricky ...

Maybe a $cachable argument would do it?

Please see my taxonomy_get_tree() cache patch at http://drupal.org/node/106015. Maybe that would help. At least they both should use the same implementation. I removed the static var there but may need to bring it back so we only pull from the cache once per page request.

Still applies but marking as needs work per Dries.

Bumping to 7.

tagging.

This is still valid, fresh patch.

+++ modules/taxonomy/taxonomy.module	2 Jan 2010 13:50:32 -0000
@@ -610,19 +612,25 @@ function taxonomy_vocabulary_get_names()
+    $tids = &drupal_static(__FUNCTION__, array());
+    if (isset($tids[$key][$tid])) {
+      $parents = $tids[$key][$tid];
+    }
+    else {
+      // Long code to set value of $parents.
+    }

+++ modules/taxonomy/taxonomy.module	2 Jan 2010 13:50:32 -0000
@@ -660,23 +668,30 @@ function taxonomy_get_parents_all($tid) 
+    $tids = &drupal_static(__FUNCTION__, array());
+  if (!isset($tids[$vid][$tid])) {
+    // Long code to set value of $children.
+  }
+  else {
+    $children = $tids[$vid][$tid];
   }

Looks good from an 'the code works' perspective, however, the anal part of me noted that the logic is reversed between instances. For taxonomy_get_children(), I would put the return of the cached $children variable in the 'if', and generate the value in the 'else' to be consistent with the other function.

10 days to code freeze. Better review yourself.

Yeah I thought about that when writing it, but couldn't decide which was best, sometimes it's better to just pick one though :p here it is as requested.

Yay - looks great!

Hm. It's not clear to me in my current, bleary-eyed state whether the most recent patch addresses Dries's concern at #4. Could someone enlighten me?

That's covered by drupal_static() and taxonomy_static_reset().

Comitted to CVS HEAD. Thanks.