weekly release 3.1dev
[moodle.git] / lib / classes / php_time_limit.php
CommitLineData
366b19a9 1<?php
2// This file is part of Moodle - http://moodle.org/
3//
4// Moodle is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// Moodle is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU General Public License for more details.
13//
14// You should have received a copy of the GNU General Public License
15// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
16
17/**
18 * PHP time limit management.
19 *
20 * @package core
21 * @copyright 2013 The Open University
22 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
23 */
24
25defined('MOODLE_INTERNAL') || die();
26
27/**
28 * Utility class to manage PHP time limit.
29 */
30class core_php_time_limit {
31 /**
32 * @var int Current end time of time limit (-1 if not set)
33 */
34 protected static $currentend = -1;
35
36 /**
37 * @var array Data for unit testing
38 */
39 protected static $unittestdata = array();
40
41 /**
42 * Sets the PHP time limit to a number of seconds from now.
43 *
44 * This function will always extend the time limit (in other words, if the time
45 * limit has already been set further in the future, it will do nothing).
46 *
47 * In order to support front-end servers which may time out silently if no
48 * output is displayed, you should ideally only call this function if you expect
49 * some output to be displayed at the same time. (I.e. if you call this function
50 * each time around a loop, also display some output each time around the loop,
51 * such as a progress bar update.)
52 *
53 * @param int $newlimit Limit in seconds from now (0 = infinite)
54 */
55 public static function raise($newlimit = 0) {
56 global $CFG;
57
58 // Special behaviour in unit tests so that we can check the value.
59 if (PHPUNIT_TEST) {
60 self::$unittestdata[] = $newlimit;
61 }
62
63 // If the time limit has already been set to 'infinite', ignore. Also do
64 // nothing in CLI scripts (including unit testing) which are set to
65 // infinite by default.
66 if (self::$currentend === 0 || CLI_SCRIPT) {
67 return;
68 }
69
70 // Maximum time limit can be set in config. This can be useful for front-end
71 // server systems; if the front-end server has a timeout without receiving
72 // data, it's helpful to set this timeout lower to ensure that a suitable
73 // error gets logged.
0b2f11db 74 if (!empty($CFG->maxtimelimit)) {
366b19a9 75 $realtimeout = max(1, $CFG->maxtimelimit);
76 if ($newlimit === 0) {
77 $newlimit = $realtimeout;
78 } else {
79 $newlimit = min($newlimit, $realtimeout);
80 }
81 }
82
83 // If new time limit is infinite, just set that.
84 if ($newlimit === 0) {
85 self::$currentend = 0;
86 @set_time_limit(0);
87 return;
88 }
89
90 // Calculate time limits to make sure it's longer than previous.
91 $now = time();
92 $newend = $now + $newlimit;
93 if (self::$currentend !== -1 && self::$currentend > $newend) {
94 // Existing time limit is already longer, so do nothing.
95 return;
96 }
97
98 // Set time limit and update current value.
99 @set_time_limit($newlimit);
100 self::$currentend = $newend;
101 }
102
103 /**
104 * For unit testing, returns an array of the values set during test.
105 *
106 * @return array Array of values set
107 */
108 public static function get_and_clear_unit_test_data() {
109 $data = self::$unittestdata;
110 self::$unittestdata = array();
111 return $data;
112 }
113}