issue #130: add caching of the list of matching users

Author: dmitriim

classes/rule.php

@@ -189,5 +189,6 @@ protected function after_create() {
      */
     protected function after_update($result) {
         cache_helper::purge_by_event('ruleschanged');
+        cache::make('tool_dynamic_cohorts', 'matchinguserscount')->delete($this->get('id'));
     }
 }

classes/rule_manager.php

@@ -225,9 +225,11 @@ public static function delete_rule(rule $rule): void {
     public static function get_matching_users(rule $rule, ?int $userid = null): array {
         global $DB;
 
-        $conditions = $rule->get_condition_records();
+        $matchinguserscache = cache::make('tool_dynamic_cohorts', 'matchinguserscount');
 
+        $conditions = $rule->get_condition_records();
         if (empty($conditions)) {
+            $matchinguserscache->set($rule->get('id'), 0);
             return [];
         }
 
@@ -238,15 +240,21 @@ public static function get_matching_users(rule $rule, ?int $userid = null): arra
         } catch (\Exception $exception ) {
             self::trigger_matching_failed_event($rule, $exception->getMessage());
             $rule->mark_broken();
+            $matchinguserscache->set($rule->get('id'), 0);
 
             return [];
         }
 
         try {
-            return $DB->get_records_sql($sql . $sqldata->get_join() . ' WHERE ' . $sqldata->get_where(), $sqldata->get_params());
+            $users = $DB->get_records_sql($sql . $sqldata->get_join() . ' WHERE ' . $sqldata->get_where(), $sqldata->get_params());
+            if (empty($userid)) {
+                $matchinguserscache->set($rule->get('id'), count($users));
+            }
+            return $users;
         } catch (\Exception $exception) {
             self::trigger_matching_failed_event($rule, $exception->getMessage());
             $rule->mark_broken();
+            $matchinguserscache->set($rule->get('id'), 0);
 
             return [];
         }
@@ -256,37 +264,48 @@ public static function get_matching_users(rule $rule, ?int $userid = null): arra
      * Get count of matching users for a given rule.
      *
      * @param \tool_dynamic_cohorts\rule $rule
-     * @param int|null $userid
      *
      * @return int
      */
-    public static function get_matching_users_count(rule $rule, ?int $userid = null): int {
+    public static function get_matching_users_count(rule $rule): int {
         global $DB;
 
+        $matchinguserscache = cache::make('tool_dynamic_cohorts', 'matchinguserscount');
+
+        $count = $matchinguserscache->get($rule->get('id'));
+        if ($count !== false) {
+            return $count;
+        }
+
         $conditions = $rule->get_condition_records();
 
         if (empty($conditions)) {
+            $matchinguserscache->set($rule->get('id'), 0);
             return 0;
         }
 
         $sql = "SELECT COUNT(DISTINCT u.id) cnt FROM {user} u";
 
         try {
-            $sqldata = condition_manager::build_sql_data($conditions, $rule->get('operator'), $userid);
+            $sqldata = condition_manager::build_sql_data($conditions, $rule->get('operator'));
         } catch (\Exception $exception ) {
             self::trigger_matching_failed_event($rule, $exception->getMessage());
             $rule->mark_broken();
 
+            $matchinguserscache->set($rule->get('id'), 0);
             return 0;
         }
 
         try {
             $result = $DB->get_record_sql($sql . $sqldata->get_join() . ' WHERE ' . $sqldata->get_where(), $sqldata->get_params());
+            $matchinguserscache->set($rule->get('id'), $result->cnt);
+
             return $result->cnt;
         } catch (\Exception $exception) {
             self::trigger_matching_failed_event($rule, $exception->getMessage());
             $rule->mark_broken();
 
+            $matchinguserscache->set($rule->get('id'), 0);
             return 0;
         }
     }

db/caches.php

@@ -44,4 +44,9 @@
             'conditionschanged',
         ],
     ],
+    'matchinguserscount' => [
+        'mode' => cache_store::MODE_APPLICATION,
+        'simpledata' => true,
+        'staticacceleration' => true,
+    ],
 ];

lang/en/tool_dynamic_cohorts.php

@@ -36,6 +36,7 @@
 $string['bulkprocessing'] = 'Bulk processing';
 $string['bulkprocessing_help'] = 'If this option is enabled, users will be added and removed from cohort in bulk. This will significantly improve processing performance. However, using this option will suppress triggering events when users added or removed from cohort.';
 $string['cachedef_conditionrecords'] = 'Conditions for a rule';
+$string['cachedef_matchingusers'] = 'Matching users for a rule';
 $string['cachedef_rulesconditions'] = 'Rules with a specific condition';
 $string['cohort'] = 'Cohort';
 $string['cohortid'] = 'Cohort';

version.php

@@ -26,7 +26,7 @@
 
 $plugin->component = 'tool_dynamic_cohorts';
 $plugin->release = 2024112100;
-$plugin->version = 2024112101;
+$plugin->version = 2024112102;
 $plugin->requires = 2022112800;
 $plugin->supported = [404, 405];
 $plugin->maturity = MATURITY_STABLE;