From 28fd710f8406fab5dff858046dc4cc86dd7276c3 Mon Sep 17 00:00:00 2001
From: Andrew Nicols <andrew@nicols.co.uk>
Date: Fri, 1 Jun 2018 11:37:35 +0800
Subject: [PATCH] MDL-46881 core_task: Add a logging trait

---
 lib/classes/task/logging_trait.php | 113 +++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 lib/classes/task/logging_trait.php

diff --git a/lib/classes/task/logging_trait.php b/lib/classes/task/logging_trait.php
new file mode 100644
index 00000000000..ac2d4014a0b
--- /dev/null
+++ b/lib/classes/task/logging_trait.php
@@ -0,0 +1,113 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * This file defines a trait to assist with logging in tasks.
+ *
+ * @package    core
+ * @copyright  2018 Andrew Nicols <andrew@nicols.co.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core\task;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * This trait includes functions to assist with logging in tasks.
+ *
+ * @package    core
+ * @copyright  2018 Andrew Nicols <andrew@nicols.co.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+trait logging_trait {
+
+    /**
+     * @var \progress_trace
+     */
+    protected $_trace = null;
+
+    /**
+     * @var \stdClass
+     */
+    protected $_tracestats = null;
+
+    /**
+     * Get the progress_trace.
+     *
+     * @return  \progress_trace
+     */
+    protected function get_trace() {
+        if (null === $this->_trace) {
+            $this->_trace = new \text_progress_trace();
+            $this->_tracestats = (object) [];
+        }
+
+        return $this->_trace;
+    }
+
+    /**
+     * Log a message to the progress tracer.
+     *
+     * @param   string  $message
+     * @param   int     $depth
+     */
+    protected function log($message, $depth = 1) {
+        $this->get_trace()
+            ->output($message, $depth);
+    }
+
+    /**
+     * Log a start message to the progress tracer.
+     *
+     * @param   string  $message
+     * @param   int     $depth
+     */
+    protected function log_start($message, $depth = 0) {
+        $this->get_trace();
+
+        if (defined('MDL_PERFTOLOG') && MDL_PERFTOLOG) {
+            $this->_tracestats->$depth = [
+                'mem' => memory_get_usage(),
+                'time' => microtime(),
+            ];
+        }
+
+        $this->log($message, $depth);
+    }
+
+    /**
+     * Log an end message to the progress tracer.
+     *
+     * @param   string  $message
+     * @param   int     $depth
+     */
+    protected function log_finish($message, $depth = 0) {
+        $this->log($message, $depth);
+        if (isset($this->_tracestats->$depth)) {
+            $startstats = $this->_tracestats->$depth;
+            $this->log(
+                    sprintf("Time taken %s, memory total: %s, Memory growth: %s, Memory peak: %s",
+                        microtime_diff($startstats['time'], microtime()),
+                        display_size(memory_get_usage()),
+                        display_size(memory_get_usage() - $startstats['mem']),
+                        display_size(memory_get_peak_usage())
+                    ),
+                    $depth + 1
+                );
+        }
+    }
+}
-- 
2.17.1