CRM-20722: 'Lock wait timeout exceeded' error triggered on smart grou…

…p cache rebuild

This patch is merged upstream & I am submitting it &
civicrm#10943

to our codebase.

Doing this
a) syncs us with upstream in the area we are working on
b) adds some code consolidation making it easier for us to tinker with the impact of
cache tables.

Note that this change switches from one sql call to many when clearing groups from
the group_contact_cache table. I'm thinking this is probably not a problem for us as we have
not that many groups (& hopefully we can further reduce them).

Also the apparent COMMIT is a bit of a a myth - CRM_Core_Transaction does weird complex
transaction nesting stuff...

Change-Id: I3d6505b04af1134884f660d71316afb2490221d1

CRM/Contact/BAO/GroupContactCache.php

@@ -300,12 +300,12 @@ public static function updateCacheTime($groupID, $processed) {
    * @todo remove last call to this function from outside the class then make function protected,
    * enforce groupID as an array & remove non group handling.
    *
-   * @param int $groupID
+   * @param int $groupIDs
    *   the groupID to delete cache entries, NULL for all groups.
    * @param bool $onceOnly
    *   run the function exactly once for all groups.
    */
-  public static function remove($groupID = NULL, $onceOnly = TRUE) {
+  public static function remove($groupIDs = NULL, $onceOnly = TRUE) {
     static $invoked = FALSE;
 
     // typically this needs to happy only once per instance
@@ -316,21 +316,21 @@ public static function remove($groupID = NULL, $onceOnly = TRUE) {
     if (
       $onceOnly &&
       $invoked &&
-      $groupID == NULL
+      $groupIDs == NULL
     ) {
       return;
     }
 
-    if ($groupID == NULL) {
+    if ($groupIDs == NULL) {
       $invoked = TRUE;
     }
-    elseif (is_array($groupID)) {
-      foreach ($groupID as $gid) {
+    elseif (is_array($groupIDs)) {
+      foreach ($groupIDs as $gid) {
         unset(self::$_alreadyLoaded[$gid]);
       }
     }
-    elseif ($groupID && array_key_exists($groupID, self::$_alreadyLoaded)) {
-      unset(self::$_alreadyLoaded[$groupID]);
+    elseif ($groupIDs && array_key_exists($groupIDs, self::$_alreadyLoaded)) {
+      unset(self::$_alreadyLoaded[$groupIDs]);
     }
 
     $refresh = NULL;
@@ -340,7 +340,7 @@ public static function remove($groupID = NULL, $onceOnly = TRUE) {
       2 => array(self::getRefreshDateTime(), 'String'),
     );
 
-    if (!isset($groupID)) {
+    if (!isset($groupIDs)) {
       if ($smartGroupCacheTimeout == 0) {
         $query = "
 DELETE FROM civicrm_group_contact_cache
@@ -352,7 +352,6 @@ public static function remove($groupID = NULL, $onceOnly = TRUE) {
 ";
       }
       else {
-
         $query = "
 DELETE     gc
 FROM       civicrm_group_contact_cache gc
@@ -372,44 +371,49 @@ public static function remove($groupID = NULL, $onceOnly = TRUE) {
 AND    refresh_date IS NULL
 ";
       }
-    }
-    elseif (is_array($groupID)) {
-      $groupIDs = implode(', ', $groupID);
-      $query = "
-DELETE     g
-FROM       civicrm_group_contact_cache g
-WHERE      g.group_id IN ( $groupIDs )
-";
-      $update = "
-UPDATE civicrm_group g
-SET    cache_date = null,
-       refresh_date = null
-WHERE  id IN ( $groupIDs )
-";
+
+      CRM_Core_DAO::executeQuery($query, $params);
+      if ($refresh) {
+        CRM_Core_DAO::executeQuery($refresh, $params);
+      }
+      // also update the cache_date for these groups
+      CRM_Core_DAO::executeQuery($update, $params);
     }
     else {
-      $query = "
-DELETE     g
-FROM       civicrm_group_contact_cache g
-WHERE      g.group_id = %1
-";
-      $update = "
-UPDATE civicrm_group g
-SET    cache_date = null,
-       refresh_date = null
-WHERE  id = %1
-";
-      $params = array(1 => array($groupID, 'Integer'));
+      foreach ((array) $groupIDs as $groupID) {
+        self::clearGroupContactCache($groupID);
+      }
     }
+  }
 
-    CRM_Core_DAO::executeQuery($query, $params);
+  /**
+   * Function to clear group contact cache and reset the corresponding
+   *  group's cache and refresh date
+   *
+   *  @param int $groupID
+   *
+   */
+  public static function clearGroupContactCache($groupID) {
+    $transaction = new CRM_Core_Transaction();
+    $query = "
+    DELETE  g
+      FROM  civicrm_group_contact_cache g
+      WHERE  g.group_id = %1 ";
 
-    if ($refresh) {
-      CRM_Core_DAO::executeQuery($refresh, $params);
-    }
+    $update = "
+  UPDATE civicrm_group g
+    SET    cache_date = null, refresh_date = null
+    WHERE  id = %1 ";
+
+    $params = array(
+      1 => array($groupID, 'Integer'),
+    );
 
+    CRM_Core_DAO::executeQuery($query, $params);
     // also update the cache_date for these groups
     CRM_Core_DAO::executeQuery($update, $params);
+
+    $transaction->commit();
   }
 
   /**