class-semaphore.php — UpdraftPlus: WP Backup & Migration Plugin 1.26.4

updraftplus / includes / class-semaphore.php

updraftplus / includes Last commit date

class-semaphore.php

262 lines

1	<?php
2	// phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery -- Direct $wpdb query is required for this operation.
3	// phpcs:disable WordPress.DB.DirectDatabaseQuery.NoCaching -- some query operations need to always receive the most up-to-date or actual data directly from the database, reducing the risk of serving stale information.
4	/**
5	* Semaphore Lock Management
6	* Adapted from WP Social under the GPL - thanks to Alex King (https://github.com/crowdfavorite/wp-social)
7	*/
8	class UpdraftPlus_Semaphore {
9
10	/**
11	* Initializes the semaphore object.
12	*
13	* @static
14	* @return UpdraftPlus_Semaphore
15	*/
16	public static function factory() {
17	return new self;
18	}
19
20	/**
21	* Lock Broke
22	*
23	* @var boolean
24	*/
25	protected $lock_broke = false;
26
27	public $lock_name = 'lock';
28
29	/**
30	* Attempts to start the lock. If the rename works, the lock is started.
31	*
32	* @return bool
33	*/
34	public function lock() {
35	global $wpdb, $updraftplus;
36
37	// Attempt to set the lock
38	// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- Dynamic table name ($wpdb->options) and lock name used in semaphore queries cannot be parameterized
39	$affected = $wpdb->query("
40	UPDATE $wpdb->options
41	SET option_name = 'updraftplus_locked_".$this->lock_name."'
42	WHERE option_name = 'updraftplus_unlocked_".$this->lock_name."'
43	");
44
45	if ('0' == $affected && !$this->stuck_check()) {
46	$updraftplus->log('Semaphore lock ('.$this->lock_name.', '.$wpdb->options.') failed (line '.__LINE__.')');
47	return false;
48	}
49
50	// Check to see if all processes are complete
51	// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- Dynamic table name ($wpdb->options) and lock name used in semaphore queries cannot be parameterized
52	$affected = $wpdb->query("
53	UPDATE $wpdb->options
54	SET option_value = CAST(option_value AS UNSIGNED) + 1
55	WHERE option_name = 'updraftplus_semaphore_".$this->lock_name."'
56	AND option_value = '0'
57	");
58	if ('1' != $affected) {
59	if (!$this->stuck_check()) {
60	$updraftplus->log('Semaphore lock ('.$this->lock_name.', '.$wpdb->options.') failed (line '.__LINE__.')');
61	return false;
62	}
63
64	// Reset the semaphore to 1
65	// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- Dynamic table name ($wpdb->options) and lock name used in semaphore queries cannot be parameterized
66	$wpdb->query("
67	UPDATE $wpdb->options
68	SET option_value = '1'
69	WHERE option_name = 'updraftplus_semaphore_".$this->lock_name."'
70	");
71
72	$updraftplus->log('Semaphore ('.$this->lock_name.', '.$wpdb->options.') reset to 1');
73	}
74
75	// Set the lock time
76	// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- Dynamic table name ($wpdb->options) and lock name used in semaphore queries cannot be parameterized
77	$wpdb->query($wpdb->prepare("
78	UPDATE $wpdb->options
79	SET option_value = %s
80	WHERE option_name = 'updraftplus_last_lock_time_".$this->lock_name."'
81	", current_time('mysql', 1)));
82	$updraftplus->log('Set semaphore last lock ('.$this->lock_name.') time to '.current_time('mysql', 1));
83
84	$updraftplus->log('Semaphore lock ('.$this->lock_name.') complete');
85	return true;
86	}
87
88	public static function ensure_semaphore_exists($semaphore) {
89	// Make sure the options for semaphores exist
90	global $wpdb, $updraftplus;
91
92	$results = $wpdb->get_results(
93	$wpdb->prepare(
94	"SELECT option_id FROM $wpdb->options WHERE option_name IN (%s, %s, %s, %s)",
95	"updraftplus_locked_$semaphore",
96	"updraftplus_unlocked_$semaphore",
97	"updraftplus_last_lock_time_$semaphore",
98	"updraftplus_semaphore_$semaphore"
99	)
100	);
101
102	if (!is_array($results) \|\| count($results) < 3) {
103
104	if (is_array($results) && count($results) > 0) {
105	$updraftplus->log("Semaphore ($semaphore, ".$wpdb->options.") in an impossible/broken state - fixing (".count($results).")");
106	} else {
107	$updraftplus->log("Semaphore ($semaphore, ".$wpdb->options.") being initialised");
108	}
109
110	$wpdb->query(
111	$wpdb->prepare(
112	"DELETE FROM $wpdb->options WHERE option_name IN (%s, %s, %s, %s)",
113	'updraftplus_locked_'.$semaphore,
114	'updraftplus_unlocked_'.$semaphore,
115	'updraftplus_last_lock_time_'.$semaphore,
116	'updraftplus_semaphore_'.$semaphore
117	)
118	);
119
120	$wpdb->query(
121	$wpdb->prepare(
122	"INSERT INTO $wpdb->options (option_name, option_value, autoload) VALUES (%s, %s, %s), (%s, %s, %s), (%s, %s, %s)",
123	'updraftplus_unlocked_'.$semaphore,
124	'1',
125	'no',
126	'updraftplus_last_lock_time_'.$semaphore,
127	current_time('mysql', 1),
128	'no',
129	'updraftplus_semaphore_'.$semaphore,
130	'0',
131	'no'
132	)
133	);
134	}
135	}
136
137	/**
138	* Increment the semaphore.
139	*
140	* @param array $filters
141	* @return Updraft_Semaphore
142	*/
143	public function increment(array $filters = array()) {
144	global $wpdb, $updraftplus;
145
146	if (count($filters)) {
147	// Loop through all of the filters and increment the semaphore
148	foreach ($filters as $priority) {
149	for ($i = 0, $j = count($priority); $i < $j; ++$i) {
150	$this->increment();
151	}
152	}
153	} else {
154	// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- Dynamic table name ($wpdb->options) and lock name used in semaphore queries cannot be parameterized
155	$wpdb->query("
156	UPDATE $wpdb->options
157	SET option_value = CAST(option_value AS UNSIGNED) + 1
158	WHERE option_name = 'updraftplus_semaphore_".$this->lock_name."'
159	");
160	$updraftplus->log('Incremented the semaphore ('.$this->lock_name.') by 1');
161	}
162
163	return $this;
164	}
165
166	/**
167	* Decrements the semaphore.
168	*
169	* @return void
170	*/
171	public function decrement() {
172	global $wpdb, $updraftplus;
173
174	// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- Dynamic table name ($wpdb->options) and lock name used in semaphore queries cannot be parameterized
175	$wpdb->query("
176	UPDATE $wpdb->options
177	SET option_value = CAST(option_value AS UNSIGNED) - 1
178	WHERE option_name = 'updraftplus_semaphore_".$this->lock_name."'
179	AND CAST(option_value AS UNSIGNED) > 0
180	");
181	$updraftplus->log('Decremented the semaphore ('.$this->lock_name.') by 1');
182	}
183
184	/**
185	* Unlocks the process.
186	*
187	* @return bool
188	*/
189	public function unlock() {
190	global $wpdb, $updraftplus;
191
192	// Decrement for the master process.
193	$this->decrement();
194
195	// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- Dynamic table name ($wpdb->options) and lock name used in semaphore queries cannot be parameterized
196	$result = $wpdb->query("
197	UPDATE $wpdb->options
198	SET option_name = 'updraftplus_unlocked_".$this->lock_name."'
199	WHERE option_name = 'updraftplus_locked_".$this->lock_name."'
200	");
201
202	if ('1' == $result) {
203	$updraftplus->log('Semaphore ('.$this->lock_name.') unlocked');
204	return true;
205	}
206
207	$updraftplus->log('Semaphore ('.$this->lock_name.', '.$wpdb->options.') still locked ('.$result.')');
208	return false;
209	}
210
211	/**
212	* Attempts to jiggle the stuck lock loose.
213	*
214	* @return bool
215	*/
216	private function stuck_check() {
217	global $wpdb, $updraftplus;
218
219	// Check to see if we already broke the lock.
220	if ($this->lock_broke) {
221	return true;
222	}
223
224	$current_time = current_time('mysql', 1);
225	$three_minutes_before = gmdate('Y-m-d H:i:s', time()-(defined('UPDRAFTPLUS_SEMAPHORE_LOCK_WAIT') ? UPDRAFTPLUS_SEMAPHORE_LOCK_WAIT : 180));
226
227	// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- Dynamic table name ($wpdb->options) and lock name used in semaphore queries cannot be parameterized
228	$affected = $wpdb->query($wpdb->prepare("
229	UPDATE $wpdb->options
230	SET option_value = %s
231	WHERE option_name = 'updraftplus_last_lock_time_".$this->lock_name."'
232	AND option_value <= %s
233	", $current_time, $three_minutes_before));
234
235	if ('1' == $affected) {
236	$updraftplus->log('Semaphore ('.$this->lock_name.', '.$wpdb->options.') was stuck, set lock time to '.$current_time);
237	$this->lock_broke = true;
238	return true;
239	}
240
241	// Check if lock is greater that 24 hours
242	$last_lock_time = strtotime(UpdraftPlus_Options::get_updraft_option('updraftplus_last_lock_time_'.$this->lock_name, $current_time));
243	$next_day = strtotime($current_time.' +1 day');
244	if ($last_lock_time > $next_day) {
245	$this->lock_broke = true;
246	return true;
247	}
248
249	return false;
250	}
251
252	/**
253	* Remove a given lock from the options table in the database
254	*
255	* @return Boolean True if the lock has successfully been removed, false otherwise
256	*/
257	public function delete_lock() {
258	global $wpdb;
259	return (bool) $wpdb->query($wpdb->prepare("DELETE FROM {$wpdb->options} WHERE option_name = %s", $this->lock_name));
260	}
261	} // End UpdraftPlus_Semaphore
262