broken-link-notifier / includes / cache.php

cache.php in Broken Link Notifier trunk, at includes/cache.php

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1	<?php
2	/**
3	* Cache class file.
4	*/
5
6	// Exit if accessed directly.
7	if ( !defined( 'ABSPATH' ) ) {
8	exit;
9	}
10
11
12	/**
13	* Initialize the class
14	*/
15
16	new BLNOTIFIER_CACHE();
17
18
19	/**
20	* Cache class.
21	*/
22	class BLNOTIFIER_CACHE {
23
24	/**
25	* The table name
26	*
27	* @var string
28	*/
29	protected $table;
30
31
32	/**
33	* Length of time to cache links
34	*
35	* @var int
36	*/
37	public $cache_time_in_seconds;
38
39
40	/**
41	* Whether to mark (cached) at the end of the text response
42	*
43	* @var boolean
44	*/
45	private $mark_cached_in_text = false;
46
47
48	/**
49	* Constructor
50	*/
51	public function __construct() {
52
53	$this->cache_time_in_seconds = absint( get_option( 'blnotifier_cache', 0 ) );
54
55	global $wpdb;
56	$this->table = $wpdb->prefix . 'blnotifier_cache';
57	$this->maybe_create_table();
58	$this->maybe_cleanup_cache();
59	$this->maybe_delete_table_if_disabled();
60
61	} // End __construct()
62
63
64	/**
65	* Create the cache table if it doesn't already exist.
66	*/
67	public function maybe_create_table() {
68	if ( $this->cache_time_in_seconds === 0 ) {
69	return;
70	}
71
72	global $wpdb;
73
74	if ( $wpdb->get_var( "SHOW TABLES LIKE '{$this->table}'" ) !== $this->table ) { // phpcs:ignore
75	require_once ABSPATH . 'wp-admin/includes/upgrade.php';
76
77	$charset_collate = $wpdb->get_charset_collate();
78
79	$sql = "CREATE TABLE {$this->table} (
80	id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
81	link TEXT NOT NULL,
82	http_code SMALLINT UNSIGNED NOT NULL,
83	type VARCHAR(20) NOT NULL,
84	status_text TEXT,
85	last_checked DATETIME NOT NULL,
86	PRIMARY KEY (id),
87	UNIQUE KEY link_unique (link(191))
88	) $charset_collate;";
89
90	dbDelta( $sql );
91	}
92	} // End maybe_create_table()
93
94
95	/**
96	* Delete the table if cache is disabled
97	*
98	* @return void
99	*/
100	public function maybe_delete_table_if_disabled() {
101	if ( $this->cache_time_in_seconds === 0 ) {
102	$this->delete_cache_table();
103	}
104	} // End maybe_delete_table_if_disabled()
105
106
107	/**
108	* Delete the cache table from the database.
109	*/
110	public function delete_cache_table() {
111	global $wpdb;
112
113	$wpdb->query( "DROP TABLE IF EXISTS {$this->table}" ); // phpcs:ignore
114	} // End delete_cache_table()
115
116
117	/**
118	* Remove expired cache entries older than 8 hours.
119	*/
120	public function maybe_cleanup_cache() {
121	if ( $this->cache_time_in_seconds === 0 ) {
122	return;
123	}
124
125	global $wpdb;
126
127	$expiration_time = gmdate( 'Y-m-d H:i:s', time() - $this->cache_time_in_seconds );
128
129	$wpdb->query( $wpdb->prepare( // phpcs:ignore
130	"DELETE FROM {$this->table} WHERE last_checked < %s",
131	$expiration_time
132	) );
133	} // End maybe_cleanup_cache()
134
135
136	/**
137	* Retrieve a cached link if it's still valid.
138	*
139	* @param string $link The URL to look up.
140	* @return array\|false The cached status or false if not found or expired.
141	*/
142	public function get_cached_link( $link ) {
143	if ( $this->cache_time_in_seconds === 0 ) {
144	return false;
145	}
146
147	global $wpdb;
148
149	$row = $wpdb->get_row( $wpdb->prepare( // phpcs:ignore
150	"SELECT * FROM {$this->table} WHERE link = %s AND last_checked >= %s LIMIT 1",
151	$link,
152	gmdate( 'Y-m-d H:i:s', time() - $this->cache_time_in_seconds )
153	), ARRAY_A );
154
155	if ( $row ) {
156	$mark_cached = $this->mark_cached_in_text ? ' (cached)' : '';
157	return [
158	'type' => $row[ 'type' ],
159	'code' => (int) $row[ 'http_code' ],
160	'text' => $row[ 'status_text' ] . $mark_cached,
161	'link' => $row[ 'link' ]
162	];
163	}
164
165	return false;
166	} // End get_cached_link()
167
168
169	/**
170	* Store a link in the cache if it's good (not broken or warning).
171	*
172	* @param array $status The link status array.
173	*/
174	public function set_cached_link( $status ) {
175	if ( $this->cache_time_in_seconds === 0 ) {
176	return;
177	}
178
179	if ( ! is_array( $status ) \|\| ! isset( $status[ 'type' ], $status[ 'code' ], $status[ 'text' ], $status[ 'link' ] ) ) {
180	return;
181	}
182
183	if ( in_array( $status[ 'type' ], [ 'broken', 'warning' ], true ) ) {
184	return;
185	}
186
187	global $wpdb;
188
189	$wpdb->replace( // phpcs:ignore
190	$this->table,
191	[
192	'link' => $status[ 'link' ],
193	'http_code' => absint( $status[ 'code' ] ),
194	'type' => sanitize_text_field( $status[ 'type' ] ),
195	'status_text' => sanitize_text_field( $status[ 'text' ] ),
196	'last_checked' => current_time( 'mysql', 1 )
197	],
198	[
199	'%s',
200	'%d',
201	'%s',
202	'%s',
203	'%s'
204	]
205	);
206	} // End set_cached_link()
207
208	}