ActionScheduler_OptionLock.php — WooCommerce 10.9.4

woocommerce / packages / action-scheduler / classes / ActionScheduler_OptionLock.php

woocommerce / packages / action-scheduler / classes Last commit date

ActionScheduler_OptionLock.php

137 lines

1	<?php
2
3	/**
4	* Provide a way to set simple transient locks to block behaviour
5	* for up-to a given duration.
6	*
7	* Class ActionScheduler_OptionLock
8	*
9	* @since 3.0.0
10	*/
11	class ActionScheduler_OptionLock extends ActionScheduler_Lock {
12
13	/**
14	* Set a lock using options for a given amount of time (60 seconds by default).
15	*
16	* Using an autoloaded option avoids running database queries or other resource intensive tasks
17	* on frequently triggered hooks, like 'init' or 'shutdown'.
18	*
19	* For example, ActionScheduler_QueueRunner->maybe_dispatch_async_request() uses a lock to avoid
20	* calling ActionScheduler_QueueRunner->has_maximum_concurrent_batches() every time the 'shutdown',
21	* hook is triggered, because that method calls ActionScheduler_QueueRunner->store->get_claim_count()
22	* to find the current number of claims in the database.
23	*
24	* @param string $lock_type A string to identify different lock types.
25	* @bool True if lock value has changed, false if not or if set failed.
26	*/
27	public function set( $lock_type ) {
28	global $wpdb;
29
30	$lock_key = $this->get_key( $lock_type );
31	$existing_lock_value = $this->get_existing_lock( $lock_type );
32	$new_lock_value = $this->new_lock_value( $lock_type );
33
34	// The lock may not exist yet, or may have been deleted.
35	if ( empty( $existing_lock_value ) ) {
36	return (bool) $wpdb->insert(
37	$wpdb->options,
38	array(
39	'option_name' => $lock_key,
40	'option_value' => $new_lock_value,
41	'autoload' => 'no',
42	)
43	);
44	}
45
46	if ( $this->get_expiration_from( $existing_lock_value ) >= time() ) {
47	return false;
48	}
49
50	// Otherwise, try to obtain the lock.
51	return (bool) $wpdb->update(
52	$wpdb->options,
53	array( 'option_value' => $new_lock_value ),
54	array(
55	'option_name' => $lock_key,
56	'option_value' => $existing_lock_value,
57	)
58	);
59	}
60
61	/**
62	* If a lock is set, return the timestamp it was set to expiry.
63	*
64	* @param string $lock_type A string to identify different lock types.
65	* @return bool\|int False if no lock is set, otherwise the timestamp for when the lock is set to expire.
66	*/
67	public function get_expiration( $lock_type ) {
68	return $this->get_expiration_from( $this->get_existing_lock( $lock_type ) );
69	}
70
71	/**
72	* Given the lock string, derives the lock expiration timestamp (or false if it cannot be determined).
73	*
74	* @param string $lock_value String containing a timestamp, or pipe-separated combination of unique value and timestamp.
75	*
76	* @return false\|int
77	*/
78	private function get_expiration_from( $lock_value ) {
79	$lock_string = explode( '\|', $lock_value );
80
81	// Old style lock?
82	if ( count( $lock_string ) === 1 && is_numeric( $lock_string[0] ) ) {
83	return (int) $lock_string[0];
84	}
85
86	// New style lock?
87	if ( count( $lock_string ) === 2 && is_numeric( $lock_string[1] ) ) {
88	return (int) $lock_string[1];
89	}
90
91	return false;
92	}
93
94	/**
95	* Get the key to use for storing the lock in the transient
96	*
97	* @param string $lock_type A string to identify different lock types.
98	* @return string
99	*/
100	protected function get_key( $lock_type ) {
101	return sprintf( 'action_scheduler_lock_%s', $lock_type );
102	}
103
104	/**
105	* Supplies the existing lock value, or an empty string if not set.
106	*
107	* @param string $lock_type A string to identify different lock types.
108	*
109	* @return string
110	*/
111	private function get_existing_lock( $lock_type ) {
112	global $wpdb;
113
114	// Now grab the existing lock value, if there is one.
115	return (string) $wpdb->get_var(
116	$wpdb->prepare(
117	"SELECT option_value FROM $wpdb->options WHERE option_name = %s",
118	$this->get_key( $lock_type )
119	)
120	);
121	}
122
123	/**
124	* Supplies a lock value consisting of a unique value and the current timestamp, which are separated by a pipe
125	* character.
126	*
127	* Example: (string) "649de012e6b262.09774912\|1688068114"
128	*
129	* @param string $lock_type A string to identify different lock types.
130	*
131	* @return string
132	*/
133	private function new_lock_value( $lock_type ) {
134	return uniqid( '', true ) . '\|' . ( time() + $this->get_duration( $lock_type ) );
135	}
136	}
137