bp_groups_prefetch_activity_object_data( array $activities )

function bp_groups_prefetch_activity_object_data( $activities ) {
	$group_ids = array();

	if ( empty( $activities ) ) {
		return $activities;
	}

	foreach ( $activities as $activity ) {
		if ( buddypress()->groups->id !== $activity->component ) {
			continue;
		}

		$group_ids[] = $activity->item_id;
	}

	if ( ! empty( $group_ids ) ) {

		// TEMPORARY - Once the 'populate_extras' issue is solved
		// in the groups component, we can do this with groups_get_groups()
		// rather than manually.
		$uncached_ids = array();
		foreach ( $group_ids as $group_id ) {
			if ( false === wp_cache_get( $group_id, 'bp_groups' ) ) {
				$uncached_ids[] = $group_id;
			}
		}

		if ( ! empty( $uncached_ids ) ) {
			global $wpdb;
			$bp = buddypress();
			$uncached_ids_sql = implode( ',', wp_parse_id_list( $uncached_ids ) );
			$groups = $wpdb->get_results( "SELECT * FROM {$bp->groups->table_name} WHERE id IN ({$uncached_ids_sql})" );
			foreach ( $groups as $group ) {
				wp_cache_set( $group->id, $group, 'bp_groups' );
			}
		}
	}

	return $activities;
}