Commit 15d50fff authored by Marina Glancy's avatar Marina Glancy
Browse files

MDL-38147 Performance improvements to coursecat class:

- Retrieve and cache only often-used fields of course category
- Removed function coursecat::get_all_visible() as potentially causing performance issues
- removed function coursecat::get_all_parents() as ineffective and unnecessary, replaced with get_parents()
- retrieve all fields from course_categories when unretrieved field is accessed

Also some code improvements:
- rename functions starting with _ , rename arguments, etc.
parent e1d54562
......@@ -42,17 +42,17 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
'id' => array('id', 0),
'name' => array('na', ''),
'idnumber' => array('in', null),
'description' => array('de', null),
'descriptionformat' => array('df', 0 /*FORMAT_MOODLE*/),
'description' => null, // not cached
'descriptionformat' => null, // not cached
'parent' => array('pa', 0),
'sortorder' => array('so', 0),
'coursecount' => array('cc', 0),
'coursecount' => null, // not cached
'visible' => array('vi', 1),
'visibleold' => array('vo', 1),
'visibleold' => null, // not cached
'timemodified' => null, // not cached
'depth' => array('dh', 1),
'path' => array('ph', null),
'theme' => array('th', null)
'theme' => null, // not cached
);
/** @var int */
......@@ -65,10 +65,10 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
protected $idnumber = null;
/** @var string */
protected $description = null;
protected $description = false;
/** @var int */
protected $descriptionformat = 0;
protected $descriptionformat = false;
/** @var int */
protected $parent = 0;
......@@ -77,16 +77,16 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
protected $sortorder = 0;
/** @var int */
protected $coursecount = 0;
protected $coursecount = false;
/** @var int */
protected $visible = 1;
/** @var int */
protected $visibleold = 1;
protected $visibleold = false;
/** @var int */
protected $timemodified = 0;
protected $timemodified = false;
/** @var int */
protected $depth = 0;
......@@ -95,7 +95,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
protected $path = '';
/** @var string */
protected $theme = null;
protected $theme = false;
/** @var bool */
protected $fromcache;
......@@ -112,12 +112,22 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
}
/**
* Magic method getter, redirects to read only values.
* Magic method getter, redirects to read only values. Queries from DB the fields that were not cached
* @param string $name
* @return mixed
*/
public function __get($name) {
global $DB;
if (array_key_exists($name, self::$coursecatfields)) {
if ($this->$name === false) {
// property was not retrieved from DB, retrieve all not retrieved fields
$notretrievedfields = array_diff(self::$coursecatfields, array_filter(self::$coursecatfields));
$record = $DB->get_record('course_categories', array('id' => $this->id),
join(',', array_keys($notretrievedfields)), MUST_EXIST);
foreach ($record as $key => $value) {
$this->$key = $value;
}
}
return $this->$name;
}
debugging('Invalid coursecat property accessed! '.$name, DEBUG_DEVELOPER);
......@@ -152,7 +162,9 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
public function getIterator() {
$ret = array();
foreach (self::$coursecatfields as $property => $unused) {
$ret[$property] = $this->$property;
if ($this->$property !== false) {
$ret[$property] = $this->$property;
}
}
return new ArrayIterator($ret);
}
......@@ -180,7 +192,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
* Returns coursecat object for requested category
*
* If category is not visible to user it is treated as non existing
* unless $returninvisible is set to true
* unless $alwaysreturnhidden is set to true
*
* If id is 0, the pseudo object for root category is returned (convenient
* for calling other functions such as get_children())
......@@ -189,49 +201,46 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
* @param int $strictness whether to throw an exception (MUST_EXIST) or
* return null (IGNORE_MISSING) in case the category is not found or
* not visible to current user
* @param bool $returninvisible set to true if you want an object to be
* @param bool $alwaysreturnhidden set to true if you want an object to be
* returned even if this category is not visible to the current user
* (category is hidden and user does not have
* 'moodle/category:viewhiddencategories' capability). Use with care!
* @return null|\coursecat
* @return null|coursecat
*/
public static function get($id, $strictness = MUST_EXIST, $returninvisible = false) {
public static function get($id, $strictness = MUST_EXIST, $alwaysreturnhidden = false) {
global $DB;
if (!$id) {
if (!isset(self::$coursecat0)) {
$record = array(
'id' => 0,
'visible' => 1,
'depth' => 0,
'path' => ''
);
self::$coursecat0 = new coursecat((object)$record);
$record = new stdClass();
$record->id = 0;
$record->visible = 1;
$record->depth = 0;
$record->path = '';
self::$coursecat0 = new coursecat($record);
}
return self::$coursecat0;
}
$coursecatcache = cache::make('core', 'coursecat');
$coursecat = null;
if ($coursecatcache->has($id)) {
$coursecat = $coursecatcache->get($id);
} else {
$coursecat = $coursecatcache->get($id);
if ($coursecat === false) {
$all = self::get_all_ids();
if (array_key_exists($id, $all)) {
// retrieve from DB and store in cache
list($ccselect, $ccjoin) = context_instance_preload_sql('cc.id', CONTEXT_COURSECAT, 'ctx');
$sql = "SELECT cc.* $ccselect
// Retrieve from DB only the fields that need to be stored in cache
$fields = array_filter(array_keys(self::$coursecatfields), function ($element)
{ return (self::$coursecatfields[$element] !== null); } );
$ctxselect = context_helper::get_preload_record_columns_sql('ctx');
$sql = "SELECT cc.". join(',cc.', $fields). ", $ctxselect
FROM {course_categories} cc
$ccjoin
JOIN {context} ctx ON cc.id = ctx.instanceid AND ctx.contextlevel = ?
WHERE cc.id = ?";
if ($record = $DB->get_record_sql($sql, array($id))) {
if ($record = $DB->get_record_sql($sql, array(CONTEXT_COURSECAT, $id))) {
$coursecat = new coursecat($record);
// Store in cache
$coursecatcache->set($id, $coursecat);
} else {
// should not happen because if entry is present in get_all_ids() it should be found
self::purge_cache();
}
}
}
if ($coursecat && ($returninvisible || $coursecat->is_uservisible())) {
if ($coursecat && ($alwaysreturnhidden || $coursecat->is_uservisible())) {
return $coursecat;
} else {
if ($strictness == MUST_EXIST) {
......@@ -382,8 +391,8 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
*
* Please note that this function does not verify access control.
*
* This function calls coursecat::_change_parent if field 'parent' is updated.
* It also calls coursecat::_hide or coursecat::_show if 'visible' is updated.
* This function calls coursecat::change_parent_raw if field 'parent' is updated.
* It also calls coursecat::hide_raw or coursecat::show_raw if 'visible' is updated.
* Visibility is changed first and then parent is changed. This means that
* if parent category is hidden, the current category will become hidden
* too and it may overwrite whatever was set in field 'visible'.
......@@ -443,9 +452,9 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
$changes = false;
if (isset($data->visible)) {
if ($data->visible) {
$changes = $this->_show();
$changes = $this->show_raw();
} else {
$changes = $this->_hide(0);
$changes = $this->hide_raw(0);
}
}
......@@ -454,7 +463,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
self::purge_cache();
}
$parentcat = self::get($data->parent, MUST_EXIST, true);
$this->_change_parent($parentcat);
$this->change_parent_raw($parentcat);
fix_course_sortorder();
}
......@@ -566,34 +575,13 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
return $all;
}
/**
* Returns all categories in the system
*
* This function is protected because all functions operating with the full
* list of categories (including those not visible to the current user)
* must be only inside this class
*
* @return cacheable_object_array array of coursecat objects
*/
protected static function get_all() {
$all = self::get_all_ids();
$rv = array();
foreach ($all as $id => $unused) {
if ($coursecat = self::get($id, IGNORE_MISSING, true)) {
$rv[$id] = $coursecat;
}
}
unset($rv[0]);
return $rv;
}
/**
* Returns number of ALL categories in the system regardless if
* they are visible to current user or not
*
* @return int
*/
public static function cnt_all() {
public static function count_all() {
$all = self::get_all_ids();
return count($all) - 1; // do not count 0-category
}
......@@ -661,26 +649,32 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
return false;
}
// Check all child categories (we can't call get_children() because we need to check
// not visible categories too
$all = self::get_all();
foreach ($all as $coursecat) {
if (preg_match("|^{$this->path}/|", $coursecat->path)) {
// this is a child category
if (!$coursecat->is_uservisible() ||
!has_capability('moodle/category:manage', context_coursecat::instance($coursecat->id))) {
return false;
}
// Check all child categories (not only direct children)
$sql = context_helper::get_preload_record_columns_sql('ctx');
$childcategories = $DB->get_records_sql('SELECT c.id, c.visible, '. $sql.
' FROM {context} ctx '.
' JOIN {course_categories} c ON c.id = ctx.instanceid'.
' WHERE ctx.path like ? AND ctx.contextlevel = ?',
array($context->path. '/%', CONTEXT_COURSECAT));
foreach ($childcategories as $childcat) {
context_helper::preload_from_record($childcat);
$childcontext = context_coursecat::instance($childcat->id);
if ((!$childcat->visible && !has_capability('moodle/category:viewhiddencategories', $childcontext)) ||
!has_capability('moodle/category:manage', $childcontext)) {
return false;
}
}
// Check courses
$courses = $DB->get_fieldset_sql('SELECT instanceid FROM {context} '.
'WHERE path like :pathmask and contextlevel = :courselevel',
$sql = context_helper::get_preload_record_columns_sql('ctx');
$coursescontexts = $DB->get_records_sql('SELECT ctx.instanceid AS courseid, '.
$sql. ' FROM {context} ctx '.
'WHERE ctx.path like :pathmask and ctx.contextlevel = :courselevel',
array('pathmask' => $context->path. '/%',
'courselevel' => CONTEXT_COURSE));
foreach ($courses as $courseid) {
if (!can_delete_course($courseid)) {
foreach ($coursescontexts as $ctxrecord) {
context_helper::preload_from_record($ctxrecord);
if (!can_delete_course($ctxrecord->courseid)) {
return false;
}
}
......@@ -698,7 +692,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
* @param boolean $showfeedback display some notices
* @return array return deleted courses
*/
function delete_full($showfeedback = true) {
public function delete_full($showfeedback = true) {
global $CFG, $DB;
require_once($CFG->libdir.'/gradelib.php');
require_once($CFG->libdir.'/questionlib.php');
......@@ -843,7 +837,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
if ($children) {
foreach ($children as $childcat) {
$childcat->_change_parent($newparentcat);
$childcat->change_parent_raw($newparentcat);
// Log action.
add_to_log(SITEID, "category", "move", "editcategory.php?id=$childcat->id", $childcat->id);
}
......@@ -915,8 +909,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
if (!$newparentcat) {
return false;
}
$newparents = $newparentcat->get_all_parents();
if ($newparentcat->id == $this->id || isset($newparents[$this->id])) {
if ($newparentcat->id == $this->id || in_array($this->id, $newparentcat->get_parents())) {
// can not move to itself or it's own child
return false;
}
......@@ -933,7 +926,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
*
* @param coursecat $newparentcat
*/
protected function _change_parent(coursecat $newparentcat) {
protected function change_parent_raw(coursecat $newparentcat) {
global $DB;
$context = context_coursecat::instance($this->id);
......@@ -943,8 +936,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
$DB->set_field('course_categories', 'parent', 0, array('id' => $this->id));
$newparent = context_system::instance();
} else {
$checkparents = $newparentcat->get_all_parents();
if ($newparentcat->id == $this->id || isset($checkparents[$this->id])) {
if ($newparentcat->id == $this->id || in_array($this->id, $newparentcat->get_parents())) {
// can not move to itself or it's own child
throw new moodle_exception('cannotmovecategory');
}
......@@ -967,7 +959,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
fix_course_sortorder();
$this->restore();
// Hide object but store 1 in visibleold, because when parent category visibility changes this category must become visible again.
$this->_hide(1);
$this->hide_raw(1);
}
}
......@@ -997,7 +989,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
$newparentcat = self::get((int)$newparentcat, MUST_EXIST, true);
}
if ($newparentcat->id != $this->parent) {
$this->_change_parent($newparentcat);
$this->change_parent_raw($newparentcat);
fix_course_sortorder();
$this->restore();
add_to_log(SITEID, "category", "move", "editcategory.php?id=$this->id", $this->id);
......@@ -1022,11 +1014,12 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
* @param int $visibleold value to set in field $visibleold for this category
* @return bool whether changes have been made and caches need to be purged afterwards
*/
protected function _hide($visibleold = 0) {
protected function hide_raw($visibleold = 0) {
global $DB;
$changes = false;
if ($this->id && $this->visibleold != $visibleold) {
// Note that field 'visibleold' is not cached so we must retrieve it from DB if it is missing
if ($this->id && $this->__get('visibleold') != $visibleold) {
$this->visibleold = $visibleold;
$DB->set_field('course_categories', 'visibleold', $visibleold, array('id' => $this->id));
$changes = true;
......@@ -1062,7 +1055,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
* $coursecat->update(array('visible' => 0));
*/
public function hide() {
if ($this->_hide(0)) {
if ($this->hide_raw(0)) {
self::purge_cache();
add_to_log(SITEID, "category", "hide", "editcategory.php?id=$this->id", $this->id);
}
......@@ -1080,7 +1073,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
*
* @return bool whether changes have been made and caches need to be purged afterwards
*/
protected function _show() {
protected function show_raw() {
global $DB;
if ($this->visible) {
......@@ -1115,7 +1108,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
* $coursecat->update(array('visible' => 1));
*/
public function show() {
if ($this->_show()) {
if ($this->show_raw()) {
self::purge_cache();
add_to_log(SITEID, "category", "show", "editcategory.php?id=$this->id", $this->id);
}
......@@ -1137,7 +1130,7 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
}
/**
* Returns all parents of the element. Last element in the return array is the direct parent of this category
* Returns ids of all parents of the category. Last element in the return array is the direct parent
*
* For example, if you have a tree of categories like:
* Miscellaneous (id = 1)
......@@ -1145,21 +1138,18 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
* Sub-subcategory (id = 4)
* Other category (id = 3)
*
* coursecat::get(1)->get_all_parents() == array()
* coursecat::get(2)->get_all_parents() == array(1 => coursecat(...))
* coursecat::get(4)->get_all_parents() == array(1 => coursecat(...), 2 => coursecat(...));
* coursecat::get(1)->get_parents() == array()
* coursecat::get(2)->get_parents() == array(1)
* coursecat::get(4)->get_parents() == array(1, 2);
*
* Note that this method does not check if all parents are accessible by current user
*
* @return array of coursecat objects indexed by category id
* @return array of category ids
*/
public function get_all_parents() {
$parents = array();
if ($this->parent && ($parent = self::get($this->parent, IGNORE_MISSING, true))) {
$parents += array($parent->id => $parent) +
$parent->get_all_parents();
}
return array_reverse($parents, true);
public function get_parents() {
$parents = preg_split('|/|', $this->path, 0, PREG_SPLIT_NO_EMPTY);
array_pop($parents);
return $parents;
}
/**
......
......@@ -202,6 +202,6 @@ $definitions = array(
'coursecat' => array(
'mode' => cache_store::MODE_APPLICATION,
'simplekeys' => true,
'simpledata' => false,
'persistent' => true,
),
);
......@@ -207,8 +207,8 @@ class coursecatlib_testcase extends advanced_testcase {
// check function get_children()
$this->assertEquals(array($category2->id, $category3->id), array_keys($category1->get_children()));
// check function get_all_parents()
$this->assertEquals(array($category1->id, $category2->id), array_keys($category4->get_all_parents()));
// check function get_parents()
$this->assertEquals(array($category1->id, $category2->id), $category4->get_parents());
// can not move category to itself or to it's children
$this->assertFalse($category1->can_change_parent($category2->id));
......@@ -223,7 +223,7 @@ class coursecatlib_testcase extends advanced_testcase {
}
$category4->change_parent(0);
$this->assertEquals(array(), array_keys($category4->get_all_parents()));
$this->assertEquals(array(), $category4->get_parents());
$this->assertEquals(array($category2->id, $category3->id), array_keys($category1->get_children()));
$this->assertEquals(array(), array_keys($category2->get_children()));
}
......
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