MDL-20625 new delegated transaction support in DML

patkira · Nov 7, 2009 · d5a8d9a · d5a8d9a
1 parent 88d39d6
commit d5a8d9a
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Showing 25 changed files with 772 additions and 424 deletions.
diff --git a/auth/cas/auth.php b/auth/cas/auth.php
@@ -796,7 +796,7 @@ function sync_users ($do_updates = true) {
                     $creatorrole = false;
                 }
 
-                $DB->begin_sql();
+                $transaction = $DB->start_delegated_transaction();
                 $xcount = 0;
                 $maxxcount = 100;
 
@@ -816,14 +816,8 @@ function sync_users ($do_updates = true) {
                             role_unassign($creatorrole->id, $user->id, 0, $sitecontext->id, 'cas');
                         }
                     }
-
-                    if ($xcount++ > $maxxcount) {
-                        $DB->commit_sql();
-                        $DB->begin_sql();
-                        $xcount = 0;
-                    }
                 }
-                $DB->commit_sql();
+                $transaction->allow_commit();
                 unset($users); // free mem
             }
         } else { // end do updates
@@ -851,7 +845,7 @@ function sync_users ($do_updates = true) {
                 $creatorrole = false;
             }
 
-            $DB->begin_sql();
+            $transaction = $DB->start_delegated_transaction();
             foreach ($add_users as $user) {
                 $user = $this->get_userinfo_asobj($user->username);
 
@@ -879,7 +873,7 @@ function sync_users ($do_updates = true) {
                     role_assign($creatorrole->id, $user->id, 0, $sitecontext->id, 0, 0, 0, 'cas');
                 }
             }
-            $DB->commit_sql();
+            $transaction->allow_commit();
             unset($add_users); // free mem
         } else {
             print "No users to be added\n";

diff --git a/auth/db/auth.php b/auth/db/auth.php
@@ -344,7 +344,7 @@ function sync_users($do_updates=false) {
 
         if (!empty($add_users)) {
             print_string('auth_dbuserstoadd','auth_db',count($add_users)); echo "\n";
-            $DB->begin_sql();
+            $transaction = $DB->start_delegated_transaction();
             foreach($add_users as $user) {
                 $username = $user;
                 $user = $this->get_userinfo_asobj($user);
@@ -375,7 +375,7 @@ function sync_users($do_updates=false) {
                     echo "\t"; print_string('auth_dbinsertusererror', 'auth_db', $user->username); echo "\n";
                 }
             }
-            $DB->commit_sql();
+            $transaction->allow_commit();
             unset($add_users); // free mem
         }
         return true;

diff --git a/auth/ldap/auth.php b/auth/ldap/auth.php
@@ -729,7 +729,7 @@ function sync_users($do_updates=true) {
                     $creatorrole = false;
                 }
 
-                $DB->begin_sql();
+                $transaction = $DB->start_delegated_transaction();
                 $xcount = 0;
                 $maxxcount = 100;
 
@@ -749,14 +749,8 @@ function sync_users($do_updates=true) {
                             role_unassign($creatorrole->id, $user->id, 0, $sitecontext->id, 'ldap');
                         }
                     }
-
-                    if ($xcount++ > $maxxcount) {
-                        $DB->commit_sql();
-                        $DB->begin_sql();
-                        $xcount = 0;
-                    }
                 }
-                $DB->commit_sql();
+                $transaction->allow_commit();
                 unset($users); // free mem
             }
         } else { // end do updates
@@ -785,7 +779,7 @@ function sync_users($do_updates=true) {
                 $creatorrole = false;
             }
 
-            $DB->begin_sql();
+            $transaction = $DB->start_delegated_transaction();
             foreach ($add_users as $user) {
                 $user = $this->get_userinfo_asobj($user->username);
 
@@ -816,7 +810,7 @@ function sync_users($do_updates=true) {
                     role_assign($creatorrole->id, $user->id, 0, $sitecontext->id, 0, 0, 0, 'ldap');
                 }
             }
-            $DB->commit_sql();
+            $transaction->allow_commit();
             unset($add_users); // free mem
         } else {
             print "No users to be added\n";

diff --git a/auth/mnet/auth.php b/auth/mnet/auth.php
@@ -854,7 +854,7 @@ function refresh_log($array) {
         $start = ob_start();
 
         $returnString = '';
-        $DB->begin_sql();
+        $transaction = $DB->start_delegated_transaction();
         $useridarray = array();
 
         foreach($array as $logEntry) {
@@ -883,7 +883,7 @@ function refresh_log($array) {
             }
         }
         $MNET_REMOTE_CLIENT->commit();
-        $DB->commit_sql();
+        $transaction->allow_commit();
 
         $end = ob_end_clean();
 

diff --git a/enrol/database/enrol.php b/enrol/database/enrol.php
@@ -219,7 +219,8 @@ function sync_enrolments($role = null) {
         return true;
     }
 
-    $DB->begin_sql();
+    $transaction = $DB->start_delegated_transaction();
+
     $extcourses = array();
     while ($extcourse_obj = (object)$rs->FetchRow()) { // there are more course records
         $extcourse_obj = (object)array_change_key_case((array)$extcourse_obj , CASE_LOWER);
@@ -416,7 +417,7 @@ function sync_enrolments($role = null) {
         $ers->close(); // release the handle
     }
 
-    $DB->commit_sql();
+    $transaction->allow_commit();
 
     // we are done now, a bit of housekeeping
     fix_course_sortorder();

diff --git a/group/delete.php b/group/delete.php
@@ -49,11 +49,11 @@
     if (!confirm_sesskey() ) {
         print_error('confirmsesskeybad','error',$returnurl);
     }
-    $DB->begin_sql();
+
     foreach($groupidarray as $groupid) {
         groups_delete_group($groupid);
     }
-    $DB->commit_sql();
+
     redirect($returnurl);
 } else {
     $PAGE->set_title(get_string('deleteselectedgroup', 'group'));

diff --git a/group/externallib.php b/group/externallib.php
@@ -60,36 +60,31 @@ public static function create_groups($groups) {
 
         $params = self::validate_parameters(self::create_groups_parameters(), array('groups'=>$groups));
 
-        // ideally create all groups or none at all, unfortunately myisam engine does not support transactions :-(
-        $DB->begin_sql();
-        try {
-//TODO: there is a potential problem with events propagating actions to external systems :-(
-            $groups = array();
-
-            foreach ($params['groups'] as $group) {
-                $group = (object)$group;
-
-                if (trim($group->name) == '') {
-                    throw new invalid_parameter_exception('Invalid group name');
-                }
-                if ($DB->get_record('groups', array('courseid'=>$group->courseid, 'name'=>$group->name))) {
-                    throw new invalid_parameter_exception('Group with the same name already exists in the course');
-                }
-
-                // now security checks
-                $context = get_context_instance(CONTEXT_COURSE, $group->courseid);
-                self::validate_context($context);
-                require_capability('moodle/course:managegroups', $context);
-
-                // finally create the group
-                $group->id = groups_create_group($group, false);
-                $groups[] = (array)$group;
+        $transaction = $DB->start_delegated_transaction();
+
+        $groups = array();
+
+        foreach ($params['groups'] as $group) {
+            $group = (object)$group;
+
+            if (trim($group->name) == '') {
+                throw new invalid_parameter_exception('Invalid group name');
+            }
+            if ($DB->get_record('groups', array('courseid'=>$group->courseid, 'name'=>$group->name))) {
+                throw new invalid_parameter_exception('Group with the same name already exists in the course');
             }
-        } catch (Exception $ex) {
-            $DB->rollback_sql();
-            throw $ex;
+
+            // now security checks
+            $context = get_context_instance(CONTEXT_COURSE, $group->courseid);
+            self::validate_context($context);
+            require_capability('moodle/course:managegroups', $context);
+
+            // finally create the group
+            $group->id = groups_create_group($group, false);
+            $groups[] = (array)$group;
         }
-        $DB->commit_sql();
+
+        $transaction->allow_commit();
 
         return $groups;
     }
@@ -242,30 +237,27 @@ public static function delete_groups($groupids) {
 
         $params = self::validate_parameters(self::delete_groups_parameters(), array('groupids'=>$groupids));
 
-        $DB->begin_sql();
-        try {
+        $transaction = $DB->start_delegated_transaction();
+
 // TODO: this is problematic because the DB rollback does not handle deleting of images!!
 //       there is also potential problem with events propagating action to external systems :-(
-            foreach ($params['groupids'] as $groupid) {
-                // validate params
-                $groupid = validate_param($groupid, PARAM_INTEGER);
-                if (!$group = groups_get_group($groupid, 'id, courseid', IGNORE_MISSING)) {
-                    // silently ignore attempts to delete nonexisting groups
-                    continue;
-                }
-
-                // now security checks
-                $context = get_context_instance(CONTEXT_COURSE, $group->courseid);
-                self::validate_context($context);
-                require_capability('moodle/course:managegroups', $context);
-
-                groups_delete_group($group);
+        foreach ($params['groupids'] as $groupid) {
+            // validate params
+            $groupid = validate_param($groupid, PARAM_INTEGER);
+            if (!$group = groups_get_group($groupid, 'id, courseid', IGNORE_MISSING)) {
+                // silently ignore attempts to delete nonexisting groups
+                continue;
             }
-        } catch (Exception $ex) {
-            $DB->rollback_sql();
-            throw $ex;
+
+            // now security checks
+            $context = get_context_instance(CONTEXT_COURSE, $group->courseid);
+            self::validate_context($context);
+            require_capability('moodle/course:managegroups', $context);
+
+            groups_delete_group($group);
         }
-        $DB->commit_sql();
+
+        $transaction->allow_commit();
     }
 
    /**
@@ -361,33 +353,29 @@ public static function add_groupmembers($members) {
 
         $params = self::validate_parameters(self::add_groupmembers_parameters(), array('members'=>$members));
 
-        $DB->begin_sql();
-        try {
-// TODO: there is a potential problem with events propagating action to external systems :-(
-            foreach ($params['members'] as $member) {
-                // validate params
-                $groupid = $member['groupid'];
-                $userid = $member['userid'];
+        $transaction = $DB->start_delegated_transaction();
+        // TODO: there is a potential problem with events propagating action to external systems :-(
+        foreach ($params['members'] as $member) {
+            // validate params
+            $groupid = $member['groupid'];
+            $userid = $member['userid'];
 
-                $group = groups_get_group($groupid, 'id, courseid', MUST_EXIST);
-                $user = $DB->get_record('user', array('id'=>$userid, 'deleted'=>0, 'mnethostid'=>$CFG->mnet_localhost_id), '*', MUST_EXIST);
+            $group = groups_get_group($groupid, 'id, courseid', MUST_EXIST);
+            $user = $DB->get_record('user', array('id'=>$userid, 'deleted'=>0, 'mnethostid'=>$CFG->mnet_localhost_id), '*', MUST_EXIST);
 
-                // now security checks
-                $context = get_context_instance(CONTEXT_COURSE, $group->courseid);
-                self::validate_context($context);
-                require_capability('moodle/course:managegroups', $context);
+            // now security checks
+            $context = get_context_instance(CONTEXT_COURSE, $group->courseid);
+            self::validate_context($context);
+            require_capability('moodle/course:managegroups', $context);
 
-                // now make sure user is enrolled in course - this is mandatory requirement,
-                // unfortunately this is extermely slow
-                require_capability('moodle/course:view', $context, $userid, false);
+            // now make sure user is enrolled in course - this is mandatory requirement,
+            // unfortunately this is extermely slow
+            require_capability('moodle/course:view', $context, $userid, false);
 
-                groups_add_member($group, $user);
-            }
-        } catch (Exception $ex) {
-            $DB->rollback_sql();
-            throw $ex;
+            groups_add_member($group, $user);
         }
-        $DB->commit_sql();
+
+        $transaction->allow_commit();
     }
 
    /**
@@ -429,29 +417,26 @@ public static function delete_groupmembers($members) {
 
         $params = self::validate_parameters(self::delete_groupmembers_parameters(), array('members'=>$members));
 
-        $DB->begin_sql();
-        try {
+        $transaction = $DB->start_delegated_transaction();
+
 // TODO: there is a potential problem with events propagating action to external systems :-(
         foreach ($params['members'] as $member) {
-                // validate params
-                $groupid = $member['groupid'];
-                $userid = $member['userid'];
+            // validate params
+            $groupid = $member['groupid'];
+            $userid = $member['userid'];
 
-                $group = groups_get_group($groupid, 'id, courseid', MUST_EXIST);
-                $user = $DB->get_record('user', array('id'=>$userid, 'deleted'=>0, 'mnethostid'=>$CFG->mnet_localhost_id), '*', MUST_EXIST);
+            $group = groups_get_group($groupid, 'id, courseid', MUST_EXIST);
+            $user = $DB->get_record('user', array('id'=>$userid, 'deleted'=>0, 'mnethostid'=>$CFG->mnet_localhost_id), '*', MUST_EXIST);
 
-                // now security checks
-                $context = get_context_instance(CONTEXT_COURSE, $group->courseid);
-                self::validate_context($context);
-                require_capability('moodle/course:managegroups', $context);
+            // now security checks
+            $context = get_context_instance(CONTEXT_COURSE, $group->courseid);
+            self::validate_context($context);
+            require_capability('moodle/course:managegroups', $context);
 
-                groups_remove_member($group, $user);
-            }
-        } catch (Exception $ex) {
-            $DB->rollback_sql();
-            throw $ex;
+            groups_remove_member($group, $user);
         }
-        $DB->commit_sql();
+
+        $transaction->allow_commit();
     }
 
    /**

diff --git a/lang/en_utf8/error.php b/lang/en_utf8/error.php
@@ -178,6 +178,7 @@
 $string['ddlunknownerror'] = 'Unknown DDL library error';
 $string['ddlxmlfileerror'] = 'XML database file errors found';
 $string['dmlreadexception'] = 'Error reading from database';
+$string['dmltransactionexception'] = 'Database transaction error';
 $string['dmlwriteexception'] = 'Error writing to database';
 $string['destinationcmnotexit'] = 'The destination course module does not exist';
 $string['detectedbrokenplugin'] = 'Plugin \"$a\" is defective, can not continue, sorry.';

diff --git a/lib/accesslib.php b/lib/accesslib.php
@@ -2455,24 +2455,18 @@ function cleanup_contexts() {
                      ON c.instanceid = t.id
                WHERE t.id IS NULL AND c.contextlevel = ".CONTEXT_BLOCK."
            ";
+
+    // transactions used only for performance reasons here
+    $transaction = $DB->start_delegated_transaction();
+
     if ($rs = $DB->get_recordset_sql($sql)) {
-        $DB->begin_sql();
-        $ok = true;
         foreach ($rs as $ctx) {
-            if (!delete_context($ctx->contextlevel, $ctx->instanceid)) {
-                $ok = false;
-                break;
-            }
+            delete_context($ctx->contextlevel, $ctx->instanceid);
         }
         $rs->close();
-        if ($ok) {
-            $DB->commit_sql();
-            return true;
-        } else {
-            $DB->rollback_sql();
-            return false;
-        }
     }
+
+    $transaction->allow_commit();
     return true;
 }