ActionScheduler_OptionLock.php — SureCart – Ecommerce Made Easy For Selling Physical Products, Digital Downloads, Subscriptions, Donations, & Payments 4.6.4

surecart / vendor / woocommerce / action-scheduler / classes / ActionScheduler_OptionLock.php

surecart / vendor / woocommerce / action-scheduler / classes Last commit date

ActionScheduler_OptionLock.php

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