From 0c2ddb687ab976cacbf5952a44c82b45ec0ebd03 Mon Sep 17 00:00:00 2001
From: Mark Nielsen <mark@moodlerooms.com>
Date: Tue, 22 Sep 2015 12:04:28 -0700
Subject: [PATCH] MDL-51498 core_grades: Prevent unnecessary grade record
 fetching

All of these changes make use of already
fetched grade data.  Without these changes,
the gradebook regrade process does not scale
well with very large courses because it fetches
many grade records, one at a time.
---
 lib/grade/grade_category.php | 9 ++++++---
 lib/grade/grade_item.php     | 2 +-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/lib/grade/grade_category.php b/lib/grade/grade_category.php
index f024bcb5a16..9764dc2a327 100644
--- a/lib/grade/grade_category.php
+++ b/lib/grade/grade_category.php
@@ -466,7 +466,7 @@ class grade_category extends grade_object {
                      WHERE id $usql";
             $items = $DB->get_records_sql($sql, $params);
             foreach ($items as $id => $item) {
-                $items[$id] = new grade_item($item);
+                $items[$id] = new grade_item($item, false);
             }
         }
 
@@ -501,10 +501,13 @@ class grade_category extends grade_object {
             $grademinoverrides = array();
 
             foreach ($rs as $used) {
-                $grade = new grade_grade($used);
+                $grade = new grade_grade($used, false);
                 if (isset($items[$grade->itemid])) {
                     // Prevent grade item to be fetched from DB.
                     $grade->grade_item =& $items[$grade->itemid];
+                } else if ($grade->itemid == $this->grade_item->id) {
+                    // This grade's grade item is not in $items.
+                    $grade->grade_item =& $this->grade_item;
                 }
                 if ($grade->userid != $prevuser) {
                     $this->aggregate_grades($prevuser,
@@ -882,7 +885,7 @@ class grade_category extends grade_object {
                                                        & $weights = null,
                                                        $grademinoverrides = array(),
                                                        $grademaxoverrides = array()) {
-        $category_item = $this->get_grade_item();
+        $category_item = $this->load_grade_item();
         $grademin = $category_item->grademin;
         $grademax = $category_item->grademax;
 
diff --git a/lib/grade/grade_item.php b/lib/grade/grade_item.php
index 6e23c3b2878..0d7cb1a7efc 100644
--- a/lib/grade/grade_item.php
+++ b/lib/grade/grade_item.php
@@ -680,7 +680,7 @@ class grade_item extends grade_object {
         // aggregate the category grade
         } else if ($this->is_category_item() or $this->is_course_item()) {
             // aggregate category grade item
-            $category = $this->get_item_category();
+            $category = $this->load_item_category();
             $category->grade_item =& $this;
             if ($category->generate_grades($userid)) {
                 return true;