From 236a52c4dedbadb51c01d3f6858de4572bbdac73 Mon Sep 17 00:00:00 2001
From: Neill Magill <neill.magill@nottingham.ac.uk>
Date: Tue, 18 Dec 2018 12:32:08 +0000
Subject: [PATCH 1/4] MDL-64427 category: Test getting category courses during
deletion
Adding a unit test for the situation where a course is partially
deleted when a list of courses in a category is retrived.
---
course/tests/category_test.php | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/course/tests/category_test.php b/course/tests/category_test.php
index 54899398c73..8d8b26be765 100644
--- a/course/tests/category_test.php
+++ b/course/tests/category_test.php
@@ -1080,4 +1080,26 @@ class core_course_category_testcase extends advanced_testcase {
}
return $draftid;
}
+
+ /**
+ * This test ensures that is the list of courses in a category can be retrieved while a course is being deleted.
+ */
+ public function test_get_courses_during_delete() {
+ global $DB;
+ $category = self::getDataGenerator()->create_category();
+ $course = self::getDataGenerator()->create_course(['category' => $category->id]);
+ $othercourse = self::getDataGenerator()->create_course(['category' => $category->id]);
+ $coursecategory = core_course_category::get($category->id);
+ // Get a list of courses before deletion to populate the cache.
+ $originalcourses = $coursecategory->get_courses();
+ $this->assertCount(2, $originalcourses);
+ $this->assertArrayHasKey($course->id, $originalcourses);
+ $this->assertArrayHasKey($othercourse->id, $originalcourses);
+ // Simulate the course deletion process being part way though.
+ $DB->delete_records('course', ['id' => $course->id]);
+ // Get the list of courses while a deletion is in progress.
+ $courses = $coursecategory->get_courses();
+ $this->assertCount(1, $courses);
+ $this->assertArrayHasKey($othercourse->id, $courses);
+ }
}
From 7289f5c0c1912c370486cbf6ac485b869cb6a3a4 Mon Sep 17 00:00:00 2001
From: Neill Magill <neill.magill@nottingham.ac.uk>
Date: Tue, 18 Dec 2018 11:16:03 +0000
Subject: [PATCH 2/4] MDL-64427 category: Stop error when another user deleting
courses
If you try to visit a category where another user is deleting a
course the coursecat cache may not be fresh. This is because there
is a breif time where the course record will have been deleted,
while it is deleting other course information, before the event that
triggers the coursecat cache to be purged is fired.
---
course/classes/category.php | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/course/classes/category.php b/course/classes/category.php
index 5812abdf133..15eb32a60d8 100644
--- a/course/classes/category.php
+++ b/course/classes/category.php
@@ -1582,7 +1582,10 @@ class core_course_category implements renderable, cacheable_object, IteratorAggr
}
// Prepare the list of core_course_list_element objects.
foreach ($ids as $id) {
- $courses[$id] = new core_course_list_element($records[$id]);
+ // If a course is deleted after we got the cache entry it may not exist in the database anymore.
+ if (!empty($records[$id])) {
+ $courses[$id] = new core_course_list_element($records[$id]);
+ }
}
}
return $courses;
@@ -1792,7 +1795,10 @@ class core_course_category implements renderable, cacheable_object, IteratorAggr
}
// Prepare the list of core_course_list_element objects.
foreach ($ids as $id) {
- $courses[$id] = new core_course_list_element($records[$id]);
+ // If a course is deleted after we got the cache entry it may not exist in the database anymore.
+ if (!empty($records[$id])) {
+ $courses[$id] = new core_course_list_element($records[$id]);
+ }
}
}
return $courses;
From d92acd5dcc4cb420b4a96f46dbb66c153a3f0c89 Mon Sep 17 00:00:00 2001
From: Neill Magill <neill.magill@nottingham.ac.uk>
Date: Wed, 20 Feb 2019 16:12:53 +0000
Subject: [PATCH 3/4] MDL-64427 course: Do not allow dirty cm_info during
course delete
When deleting a course (especially one containing a large amount of
data) the course mod info cache could contain entries for deleted
activities for a signifcant amount of time making it possible that
users could see errors in Moodle.
---
lib/moodlelib.php | 2 ++
1 file changed, 2 insertions(+)
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 6f4a6c08927..eb5147810f2 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -5287,6 +5287,7 @@ function remove_course_contents($courseid, $showfeedback = true, array $options
// Delete cm and its context - orphaned contexts are purged in cron in case of any race condition.
context_helper::delete_instance(CONTEXT_MODULE, $cm->id);
$DB->delete_records('course_modules', array('id' => $cm->id));
+ rebuild_course_cache($cm->course, true);
}
}
}
@@ -5323,6 +5324,7 @@ function remove_course_contents($courseid, $showfeedback = true, array $options
}
context_helper::delete_instance(CONTEXT_MODULE, $cm->id);
$DB->delete_records('course_modules', array('id' => $cm->id));
+ rebuild_course_cache($cm->course, true);
}
if ($showfeedback) {
From b26efcd8619ee4a78908d7d41c1d18b9d7f4e52b Mon Sep 17 00:00:00 2001
From: Neill Magill <neill.magill@nottingham.ac.uk>
Date: Thu, 28 Feb 2019 10:09:04 +0000
Subject: [PATCH 4/4] MDL-64427 course: Mark activities during course contents
deletion
When we want to delete all of the activities in a course we should
mark them as having a deletion in progress, as this makes them
unavailable to users immediately.
This should make it much less likely that a request to get a context
that does not exist should be made when a user accesses a page.
---
lib/moodlelib.php | 3 +++
1 file changed, 3 insertions(+)
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index eb5147810f2..cb91da2f556 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -5245,6 +5245,9 @@ function remove_course_contents($courseid, $showfeedback = true, array $options
echo $OUTPUT->notification($strdeleted.get_string('type_block_plural', 'plugin'), 'notifysuccess');
}
+ $DB->set_field('course_modules', 'deletioninprogress', '1', ['course' => $courseid]);
+ rebuild_course_cache($courseid, true);
+
// Get the list of all modules that are properly installed.
$allmodules = $DB->get_records_menu('modules', array(), '', 'name, id');