diff --git a/config-dist.php b/config-dist.php
index d03b25ddb78..314b42d3483 100644
--- a/config-dist.php
+++ b/config-dist.php
@@ -588,6 +588,14 @@ $CFG->admin = 'admin';
//
// $CFG->disablelogintoken = true;
//
+// Document conversion limit
+//
+// How many times the background task should attempt to convert a given attempt
+// before removing it from the queue. Currently this limit is only used by the
+// mod_assign conversion task.
+//
+// $CFG->conversionattemptlimit = 3;
+//
//=========================================================================
// 7. SETTINGS FOR DEVELOPMENT SERVERS - not intended for production use!!!
//=========================================================================
diff --git a/mod/assign/feedback/editpdf/classes/event/observer.php b/mod/assign/feedback/editpdf/classes/event/observer.php
index 99de1651000..9797154df9b 100644
--- a/mod/assign/feedback/editpdf/classes/event/observer.php
+++ b/mod/assign/feedback/editpdf/classes/event/observer.php
@@ -35,17 +35,7 @@ class observer {
* @param \mod_assign\event\submission_created $event
*/
public static function submission_created(\mod_assign\event\submission_created $event) {
- global $DB;
-
- $submissionid = $event->other['submissionid'];
- $submissionattempt = $event->other['submissionattempt'];
- $fields = array( 'submissionid' => $submissionid, 'submissionattempt' => $submissionattempt);
- $record = (object) $fields;
-
- $exists = $DB->get_records('assignfeedback_editpdf_queue', $fields);
- if (!$exists) {
- $DB->insert_record('assignfeedback_editpdf_queue', $record);
- }
+ self::queue_conversion($event);
}
/**
@@ -53,6 +43,14 @@ class observer {
* @param \mod_assign\event\submission_updated $event
*/
public static function submission_updated(\mod_assign\event\submission_updated $event) {
+ self::queue_conversion($event);
+ }
+
+ /**
+ * Queue the submission for processing.
+ * @param $event The submission created/updated event.
+ */
+ protected static function queue_conversion($event) {
global $DB;
$submissionid = $event->other['submissionid'];
@@ -60,9 +58,13 @@ class observer {
$fields = array( 'submissionid' => $submissionid, 'submissionattempt' => $submissionattempt);
$record = (object) $fields;
- $exists = $DB->get_records('assignfeedback_editpdf_queue', $fields);
+ $exists = $DB->get_record('assignfeedback_editpdf_queue', $fields);
if (!$exists) {
$DB->insert_record('assignfeedback_editpdf_queue', $record);
+ } else {
+ // This submission attempt was already queued, so just reset the existing failure counter to ensure it gets processed.
+ $exists->attemptedconversions = 0;
+ $DB->update_record('assignfeedback_editpdf_queue', $exists);
}
}
}
diff --git a/mod/assign/feedback/editpdf/classes/task/convert_submissions.php b/mod/assign/feedback/editpdf/classes/task/convert_submissions.php
index 6771820171e..c8c1a270b88 100644
--- a/mod/assign/feedback/editpdf/classes/task/convert_submissions.php
+++ b/mod/assign/feedback/editpdf/classes/task/convert_submissions.php
@@ -58,15 +58,21 @@ class convert_submissions extends scheduled_task {
$assignmentcache = array();
+ $conversionattemptlimit = !empty($CFG->conversionattemptlimit) ? $CFG->conversionattemptlimit : 3;
foreach ($records as $record) {
$submissionid = $record->submissionid;
$submission = $DB->get_record('assign_submission', array('id' => $submissionid), '*', IGNORE_MISSING);
- if (!$submission) {
- // Submission no longer exists.
+ if (!$submission || $record->attemptedconversions >= $conversionattemptlimit) {
+ // Submission no longer exists; or we've exceeded the conversion attempt limit.
$DB->delete_records('assignfeedback_editpdf_queue', array('id' => $record->id));
continue;
}
+ // Record that we're attempting the conversion ahead of time.
+ // We can't do this afterwards as its possible for the conversion process to crash the script entirely.
+ $record->attemptedconversions++;
+ $DB->update_record('assignfeedback_editpdf_queue', $record);
+
$assignmentid = $submission->assignment;
$attemptnumber = $record->submissionattempt;
diff --git a/mod/assign/feedback/editpdf/db/install.xml b/mod/assign/feedback/editpdf/db/install.xml
index f8bdd557993..e5c8007bbb5 100644
--- a/mod/assign/feedback/editpdf/db/install.xml
+++ b/mod/assign/feedback/editpdf/db/install.xml
@@ -64,6 +64,7 @@
+
diff --git a/mod/assign/feedback/editpdf/db/upgrade.php b/mod/assign/feedback/editpdf/db/upgrade.php
index 995afce4e18..3140fc185e8 100644
--- a/mod/assign/feedback/editpdf/db/upgrade.php
+++ b/mod/assign/feedback/editpdf/db/upgrade.php
@@ -62,5 +62,38 @@ function xmldb_assignfeedback_editpdf_upgrade($oldversion) {
// Automatically generated Moodle v3.5.0 release upgrade line.
// Put any upgrade step following this.
+ if ($oldversion < 2018051401) {
+ $table = new xmldb_table('assignfeedback_editpdf_queue');
+ $field = new xmldb_field('attemptedconversions', XMLDB_TYPE_INTEGER, '10', null,
+ XMLDB_NOTNULL, null, 0, 'submissionattempt');
+
+ if (!$dbman->field_exists($table, $field)) {
+ $dbman->add_field($table, $field);
+ }
+
+ // Attempts are removed from the queue after being processed, a duplicate row won't achieve anything productive.
+ // So look for any duplicates and remove them so we can add a unique key.
+ $sql = "SELECT MIN(id) as minid, submissionid, submissionattempt
+ FROM {assignfeedback_editpdf_queue}
+ GROUP BY submissionid, submissionattempt
+ HAVING COUNT(id) > 1";
+
+ if ($duplicatedrows = $DB->get_recordset_sql($sql)) {
+ foreach ($duplicatedrows as $row) {
+ $DB->delete_records_select('assignfeedback_editpdf_queue',
+ 'submissionid = :submissionid AND submissionattempt = :submissionattempt AND id <> :minid', (array)$row);
+ }
+ }
+ $duplicatedrows->close();
+
+ // Define key submissionid-submissionattempt to be added to assignfeedback_editpdf_queue.
+ $table = new xmldb_table('assignfeedback_editpdf_queue');
+ $key = new xmldb_key('submissionid-submissionattempt', XMLDB_KEY_UNIQUE, ['submissionid', 'submissionattempt']);
+
+ $dbman->add_key($table, $key);
+
+ upgrade_plugin_savepoint(true, 2018051401, 'assignfeedback', 'editpdf');
+ }
+
return true;
}
diff --git a/mod/assign/feedback/editpdf/version.php b/mod/assign/feedback/editpdf/version.php
index 908d1601099..63735fcffe0 100644
--- a/mod/assign/feedback/editpdf/version.php
+++ b/mod/assign/feedback/editpdf/version.php
@@ -24,7 +24,6 @@
defined('MOODLE_INTERNAL') || die();
-$plugin->version = 2018051400;
+$plugin->version = 2018051401;
$plugin->requires = 2018050800;
$plugin->component = 'assignfeedback_editpdf';
-