solid-performance / src / Performance / Lock / Drivers / Database_Driver.php

Database_Driver.php in Solid Performance – Your No-Code Caching, Performance, & Page Speed Solution 1.9.0, at src/Performance/Lock/Drivers/Database_Driver.php

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1	<?php
2	/**
3	* The database lock driver. Stores locks in a custom table.
4	*
5	* @package SolidWP\Performance
6	*/
7
8	declare( strict_types=1 );
9
10	namespace SolidWP\Performance\Lock\Drivers;
11
12	use SolidWP\Performance\Lock\Contracts\Lock;
13	use SolidWP\Performance\Lock\Lock_Entry;
14	use SolidWP\Performance\StellarWP\DB\DB;
15	use SolidWP\Performance\StellarWP\DB\QueryBuilder\QueryBuilder;
16	use Throwable;
17
18	/**
19	* The database lock driver.
20	*
21	* @package SolidWP\Performance
22	*/
23	final class Database_Driver implements Lock {
24
25	/**
26	* @var Lock_Entry
27	*/
28	private Lock_Entry $lock_entry;
29
30	/**
31	* The un-prefixed table name for storing locks.
32	*
33	* @var string
34	*/
35	private string $table;
36
37	/**
38	* The prune probability odds.
39	*
40	* @var array{0: int, 1: int}
41	*/
42	private array $lottery;
43
44	/**
45	* @param Lock_Entry $lock_entry The lock entry.
46	* @param string $table The un-prefixed database table name where locks are stored.
47	* @param array{0: int, 1: int} $lottery The prune probability odds.
48	*/
49	public function __construct(
50	Lock_Entry $lock_entry,
51	string $table,
52	array $lottery = [ 2, 100 ]
53	) {
54	$this->lock_entry = $lock_entry;
55	$this->table = $table;
56	$this->lottery = $lottery;
57	}
58
59	/**
60	* Attempt to acquire a lock.
61	*
62	* @return bool
63	*/
64	public function acquire(): bool {
65	global $wpdb;
66
67	// Don't log duplicate key errors to the error log.
68	$suppress = $wpdb->suppress_errors();
69
70	try {
71	$this->query()->insert(
72	[
73	'lock_name' => $this->lock_entry->name(),
74	'lock_owner' => $this->lock_entry->owner(),
75	'expiration' => $this->expires_at(),
76	]
77	);
78
79	$acquired = true;
80	} catch ( Throwable $e ) {
81	$updated = $this->query()->where( 'lock_name', $this->lock_entry->name() )
82	->where( 'expiration', time(), '<=' )
83	->update(
84	[
85	'lock_owner' => $this->lock_entry->owner(),
86	'expiration' => $this->expires_at(),
87	]
88	);
89
90	$acquired = $updated >= 1;
91	}
92
93	// Resume original error suppression.
94	$wpdb->suppress_errors( $suppress );
95
96	// Lottery to randomly prune expired locks. Move to a WP cron job one day.
97	if ( random_int( 1, $this->lottery[1] ) <= $this->lottery[0] ) {
98	$table = $wpdb->prefix . $this->table;
99
100	$query = DB::raw(
101	"
102	DELETE FROM $table
103	WHERE `expiration` <= %d
104	",
105	[
106	time(),
107	]
108	);
109
110	DB::query( $query->sql );
111	}
112
113	return $acquired;
114	}
115
116	/**
117	* Determine if this lock is already acquired.
118	*
119	* @return bool
120	*/
121	public function is_acquired(): bool {
122	// Grab the CONSTANT 1, should be most efficient.
123	$sql = $this->query()->select( '1' )
124	->where( 'lock_name', $this->lock_entry->name() )
125	->where( 'expiration', time(), '>' )
126	->limit( 1 )
127	->getSQL();
128
129	return (bool) DB::get_var( $sql );
130	}
131
132	/**
133	* Get the original owner of the lock.
134	*
135	* @return string
136	*/
137	public function owner(): string {
138	return (string) DB::get_var(
139	$this->query()->select( 'lock_owner' )
140	->where( 'lock_name', $this->lock_entry->name() )
141	->getSQL()
142	);
143	}
144
145	/**
146	* Release the lock, if the original owner matches the current one.
147	*
148	* @return bool
149	*/
150	public function release(): bool {
151	$owner = $this->owner();
152
153	if ( ! strlen( $owner ) ) {
154	return false;
155	}
156
157	if ( $owner !== $this->lock_entry->owner() ) {
158	return false;
159	}
160
161	return $this->force_release();
162	}
163
164	/**
165	* Force release the lock, regardless of who owns it.
166	*
167	* @return bool
168	*/
169	public function force_release(): bool {
170	return (bool) $this->query()
171	->where( 'lock_name', $this->lock_entry->name() )
172	->delete();
173	}
174
175	/**
176	* Determine the expiration time based on now + the lock's expiration in seconds.
177	*
178	* @return int
179	*/
180	private function expires_at(): int {
181	$seconds = $this->lock_entry->expiration() > 0
182	? $this->lock_entry->expiration()
183	: YEAR_IN_SECONDS * 10; // 10 years in seconds.
184
185	return time() + $seconds;
186	}
187
188	/**
189	* Get the query builder for this table.
190	*
191	* @return QueryBuilder
192	*/
193	private function query(): QueryBuilder {
194	return DB::table( $this->table );
195	}
196	}
197