studentquiz#72 Performance optimization: Don't load all attempts on s…

…tart

attempt.php

@@ -56,14 +56,27 @@
 
 $questionusage = question_engine::load_questions_usage_by_activity($attempt->questionusageid);
 
+$slots = $questionusage->get_slots();
+
+$questionids = explode(",",$attempt->ids);
+$originalnumofquestionids = count($questionids);
+
+if(!in_array($slot, $slots)) {
+    mod_studentquiz_add_question_to_attempt($questionusage, $studentquiz, $questionids, $slot-1);
+    if(count($questionids) != $originalnumofquestionids) {
+        $attempt->ids = implode(",", $questionids);
+        $DB->update_record('studentquiz_attempt', $attempt);
+    }
+}
+
 $actionurl = new moodle_url('/mod/studentquiz/attempt.php', array('cmid' => $cmid, 'id' => $attemptid, 'slot' => $slot));
 // Reroute this to attempt summary page if desired.
 $stopurl = new moodle_url('/mod/studentquiz/view.php', array('id' => $cmid));
 
 // Get Current Question.
 $question = $questionusage->get_question($slot);
 // Navigatable?
-$questionscount = $questionusage->question_count();
+$questionscount = count($questionids);
 $hasnext = $slot < $questionscount;
 $hasprevious = $slot > $questionusage->get_first_question_number();
 $canfinish = $questionusage->can_question_finish_during_attempt($slot);

db/install.xml

@@ -51,6 +51,7 @@
     </TABLE>
     <TABLE NAME="studentquiz_progress" COMMENT="Store progress information of student with this question">
         <FIELDS>
+            <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
             <FIELD NAME="questionid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false" COMMENT="Id of question"/>
             <FIELD NAME="userid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false" COMMENT="Id of user"/>
             <FIELD NAME="studentquizid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false" COMMENT="Id of studentquiz"/>
@@ -59,7 +60,6 @@
             <FIELD NAME="correctattempts" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false" COMMENT="Number of correct answers" />
         </FIELDS>
         <KEYS>
-            <KEY NAME="primary" TYPE="primary" FIELDS="questionid,userid,studentquizid"/>
             <KEY NAME="userid" TYPE="foreign" FIELDS="userid" REFTABLE="user" REFFIELDS="id"/>
             <KEY NAME="questionid" TYPE="foreign" FIELDS="questionid" REFTABLE="question" REFFIELDS="id"/>
             <KEY NAME="studentquizid" TYPE="foreign" FIELDS="studentquizid" REFTABLE="studentquiz" REFFIELDS="id"/>
@@ -121,6 +121,7 @@
             <FIELD NAME="userid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
             <FIELD NAME="questionusageid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
             <FIELD NAME="categoryid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
+            <FIELD NAME="ids" TYPE="text" NOTNULL="false" SEQUENCE="false" COMMENT=""/>
         </FIELDS>
         <KEYS>
             <KEY NAME="primary" TYPE="primary" FIELDS="id"/>

db/upgrade.php

@@ -393,5 +393,43 @@ function xmldb_studentquiz_upgrade($oldversion) {
         upgrade_mod_savepoint(true, 2018051300, 'studentquiz');
     }
 
+    if($oldversion < 2018121101) {
+        // Repair table studentquiz_progress
+        $table = new xmldb_table('studentquiz_progress');
+
+        // Adding fields to table studentquiz_progress.
+        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
+        $table->add_field('questionid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('userid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('studentquizid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('lastanswercorrect', XMLDB_TYPE_INTEGER, '2', null, XMLDB_NOTNULL, null, 0);
+        $table->add_field('attempts', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, 0);
+        $table->add_field('correctattempts', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, 0);
+
+        // Add key.
+        $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
+        $table->add_key('questionid', XMLDB_KEY_FOREIGN, array('questionid'), 'question', array('id'));
+        $table->add_key('userid', XMLDB_KEY_FOREIGN, array('userid'), 'user', array('id'));
+        $table->add_key('studentquizid', XMLDB_KEY_FOREIGN, array('studentquizid'), 'studentquiz', array('id'));
+
+        if($dbman->table_exists($table)) {
+            $dbman->drop_table($table);
+        }
+
+        // Conditionally launch create table for studentquiz_progress.
+        $dbman->create_table($table);
+
+        $table = new xmldb_table('studentquiz_attempt');
+        $field = new xmldb_field('ids', XMLDB_TYPE_TEXT, 'medium', null, null, null, null);
+
+        // Add field intro.
+        if (!$dbman->field_exists($table, $field)) {
+            $dbman->add_field($table, $field);
+        }
+
+
+        upgrade_mod_savepoint(true, 2018121101, 'studentquiz');
+    }
+
     return true;
 }

locallib.php

@@ -372,31 +372,46 @@ function mod_studentquiz_generate_attempt($ids, $studentquiz, $userid) {
     // TODO: Check if this is instance id from studentquiz table.
     $attempt->studentquizid = $studentquiz->id;
 
-    // Add questions to usage.
-    // Don't shuffle($ids) as per requirement for now.
-    $usageorder = array();
-    $allowedcategories = question_categorylist($studentquiz->categoryid);
-    foreach ($ids as $i => $questionid) {
-        $questiondata = question_bank::load_question($questionid);
-        // We have to check if the question is really from this module, limit questions to categories used in this module.
-        if (in_array($questiondata->category, $allowedcategories)) {
-            $usageorder[$i] = $questionusage->add_question($questiondata);
-        }
-    }
-
-    // Persistence.
-    // TODO: Is it necessary to start all questions here, or just the current one?
-    $questionusage->start_all_questions();
+    // Add first question to usage
+    mod_studentquiz_add_question_to_attempt($questionusage, $studentquiz, $ids);
 
     question_engine::save_questions_usage_by_activity($questionusage);
 
     $attempt->questionusageid = $questionusage->get_id();
+    $attempt->ids = implode(",",$ids);
 
     $attempt->id = $DB->insert_record('studentquiz_attempt', $attempt);
 
     return $attempt;
 }
 
+/**
+ * @param $questionusage question_usage_by_activity
+ * @param $studentquiz stdClass $studentquiz generating this attempt
+ * @param $questionids array $ids of question ids to be used in this attempt
+ * @throws coding_exception
+ */
+function mod_studentquiz_add_question_to_attempt(&$questionusage, $studentquiz, &$questionids, $lastslost = 0) {
+    $allowedcategories = question_categorylist($studentquiz->categoryid);
+    $i = $lastslost;
+    $addedquestions = 0;
+    while($addedquestions <= 0 && $i < count($questionids)) {
+        $questiondata = question_bank::load_question($questionids[$i]);
+        if (in_array($questiondata->category, $allowedcategories)) {
+            $questionusage->add_question($questiondata);
+            $addedquestions++;
+        }else{
+            unset($questionids[$i]);
+            $questionids = array_values($questionids);
+        }
+        $i++;
+    }
+
+    if($addedquestions == 0) throw new moodle_exception("Could not load any valid question for attempt", "studentquiz");
+
+    $questionusage->start_question($i);
+}
+
 
 /**
  * Trigger Report viewed Event

version.php

@@ -28,7 +28,7 @@
 defined('MOODLE_INTERNAL') || die();
 
 $plugin->component    = 'mod_studentquiz';
-$plugin->version      = 2018112900;
+$plugin->version      = 2018121101;
 $plugin->release      = 'v3.2.0';
 $plugin->requires     = 2017111306; // Version MOODLE_31, 3.1.0.
 $plugin->maturity     = MATURITY_STABLE;