Extend EntityFieldQuery to make OgMembershipFieldQuery

Of course, what use is a class if you don't actually use it! See attached second patch, with an implementation on that function I was talking about earlier - og_get_group_members_properties().

If you want to test, then set yourself up with a group and around 1,000 users. Load the group with entity_metadata_wrapper() and try accessing $wrapper->{'og_membership__' . OG_STATE_ACTIVE}->raw() (to avoid doing 1,000 user_loads) or whatever it would be and see how much of a speed improvement there is.

Yeah, I guess so.

Assume creating a standalone php file - benchmark.php, with the following code:

define('DRUPAL_ROOT', getcwd());

require_once DRUPAL_ROOT . '/includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);

$node_wrapper = entity_metadata_wrapper('node', 7);
$node_wrapper->{'members__' . OG_STATE_ACTIVE}->raw();

Take three test cases:

1. Firstly, as a control I comment out those last two lines. I use the devel module to measure the full page load time and memory
2. Now, with the attached patches in place, and node 7 being an OG with 2551 users I uncomment those two lines
3. Finally, without the patch applied.

I'm not producing repeat benchmarks or anything like that, I don't have time. My results are observational but significant enough to be representative. Fluctuations are natural but 95% of my results sit inside the quoted values. All tests are with a warm cache.

1. The control test shows that my site bootstraps at between 150-350ms and memory peaks at 6.75MB.
2. The second test adds around 100 ms to bring the average up to 200-400ms. Peak memory is up to 10.25.
3. The final test, without patches, sees loads consistently sit around 1500ms and peak memory roughly doubling to 21.5MB.

More scientific results I can't give you, but these are my observations - it's quicker.

Just wanted to bump this issue as I've been using the OgMembershipFieldQuery class in production for a long time now and I think it could be really beneficial in general.

... And here's an example of where this class is so useful:

    $user_query = new OgMembershipFieldQuery();
    $user_query
      ->setGroup('node', $profile->getIdentifier())
      ->setEntity('user')
      ->setFetchEntity();

    $members = $user_query->execute();