xspeed / includes / class-browser-cache.php

class-browser-cache.php in xSpeed Cache: AI-Powered Performance Hub with MCP, Caching & CDN 1.2.0, at includes/class-browser-cache.php

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1	<?php
2	/**
3	* Browser_Cache — writes/removes browser-cache directives in the site
4	* root .htaccess so static assets get long Cache-Control + Expires
5	* headers, and serves an nginx snippet for non-Apache hosts.
6	*
7	* Same shape as Gzip: marker block, insert_with_markers, snippet
8	* fallback. Independent toggle so users can enable browser caching
9	* without compression and vice versa.
10	*
11	* The default TTLs follow LiteSpeed/WP Rocket conventions:
12	* - Static assets (CSS/JS/fonts/images): 1 year + immutable.
13	* - HTML: 1 hour (so post edits go live the same day even if a CDN
14	* has cached the document).
15	*
16	* @package XSpeed
17	*/
18
19	declare(strict_types=1);
20
21	namespace XSpeed;
22
23	defined( 'ABSPATH' ) \|\| exit;
24
25	final class Browser_Cache {
26
27	public const MARKER = 'xSpeed Browser Cache';
28
29	public const DEFAULT_ASSET_TTL = 31536000; // 1 year
30	public const DEFAULT_HTML_TTL = 3600; // 1 hour
31
32	public static function apply( bool $enabled, array $opts = array() ): bool {
33	if ( ! function_exists( 'XSpeed\\Server::supports_htaccess' ) && class_exists( '\\XSpeed\\Server' ) ) {
34	if ( ! Server::supports_htaccess() ) {
35	return false;
36	}
37	}
38	$htaccess = ABSPATH . '.htaccess';
39	if ( ! file_exists( $htaccess ) ) {
40	return false;
41	}
42	if ( ! function_exists( 'insert_with_markers' ) ) {
43	require_once ABSPATH . 'wp-admin/includes/misc.php';
44	}
45	$rules = $enabled ? self::apache_rules( $opts ) : array();
46	return (bool) insert_with_markers( $htaccess, self::MARKER, $rules );
47	}
48
49	/**
50	* Apache rule lines. mod_expires handles the Expires header; an
51	* inline mod_headers Cache-Control mirror lets us include
52	* `immutable` (mod_expires doesn't emit it).
53	*
54	* @return string[]
55	*/
56	public static function apache_rules( array $opts = array() ): array {
57	$asset = (int) ( $opts['asset_ttl'] ?? self::DEFAULT_ASSET_TTL );
58	$html = (int) ( $opts['html_ttl'] ?? self::DEFAULT_HTML_TTL );
59	if ( $asset < 0 ) {
60	$asset = self::DEFAULT_ASSET_TTL;
61	}
62	if ( $html < 0 ) {
63	$html = self::DEFAULT_HTML_TTL;
64	}
65	return array(
66	'<IfModule mod_expires.c>',
67	' ExpiresActive On',
68	' ExpiresByType text/html "access plus ' . $html . ' seconds"',
69	' ExpiresByType text/css "access plus ' . $asset . ' seconds"',
70	' ExpiresByType text/javascript "access plus ' . $asset . ' seconds"',
71	' ExpiresByType application/javascript "access plus ' . $asset . ' seconds"',
72	' ExpiresByType application/json "access plus ' . $html . ' seconds"',
73	' ExpiresByType image/jpeg "access plus ' . $asset . ' seconds"',
74	' ExpiresByType image/png "access plus ' . $asset . ' seconds"',
75	' ExpiresByType image/webp "access plus ' . $asset . ' seconds"',
76	' ExpiresByType image/avif "access plus ' . $asset . ' seconds"',
77	' ExpiresByType image/gif "access plus ' . $asset . ' seconds"',
78	' ExpiresByType image/svg+xml "access plus ' . $asset . ' seconds"',
79	' ExpiresByType image/x-icon "access plus ' . $asset . ' seconds"',
80	' ExpiresByType font/woff2 "access plus ' . $asset . ' seconds"',
81	' ExpiresByType font/woff "access plus ' . $asset . ' seconds"',
82	' ExpiresByType font/ttf "access plus ' . $asset . ' seconds"',
83	' ExpiresByType font/otf "access plus ' . $asset . ' seconds"',
84	'</IfModule>',
85	'<IfModule mod_headers.c>',
86	' <FilesMatch "\.(css\|js\|jpg\|jpeg\|png\|gif\|webp\|avif\|svg\|ico\|woff2\|woff\|ttf\|otf\|eot\|mp4\|webm\|mp3\|ogg)$">',
87	' Header set Cache-Control "public, max-age=' . $asset . ', immutable"',
88	' </FilesMatch>',
89	' <FilesMatch "\.html$">',
90	' Header set Cache-Control "public, max-age=' . $html . '"',
91	' </FilesMatch>',
92	'</IfModule>',
93	);
94	}
95
96	/**
97	* nginx snippet — uses `expires` directive (the canonical nginx way)
98	* plus an `add_header` line for the immutable flag.
99	*/
100	/**
101	* Probe whether the server is actually emitting the Cache-Control
102	* headers our nginx snippet is supposed to add. Picks a recognisable
103	* static asset (anything in `wp-includes/css/` is always served on
104	* a WP install) and HEADs it, looking for `immutable` in the response
105	* — the unique fingerprint our snippet adds that WP core's defaults
106	* never set. Cached in a 5-minute transient so this never adds
107	* latency to the dashboard.
108	*
109	* Returns:
110	* true → headers present, no notice needed
111	* false → headers absent, snippet hasn't been pasted yet (or hasn't
112	* been reloaded into nginx), keep the notice up
113	*/
114	public static function probe_headers_present(): bool {
115	$cached = get_transient( 'xspeed_browser_cache_probe' );
116	if ( null !== $cached && false !== $cached ) {
117	return (bool) $cached;
118	}
119
120	$asset_url = includes_url( 'css/dashicons.min.css' );
121	$resp = wp_remote_head(
122	$asset_url,
123	array(
124	'timeout' => 3,
125	'sslverify' => false,
126	'redirection' => 0,
127	'headers' => array( 'Cache-Control' => 'no-cache' ),
128	)
129	);
130	if ( is_wp_error( $resp ) ) {
131	set_transient( 'xspeed_browser_cache_probe', 0, MINUTE_IN_SECONDS );
132	return false;
133	}
134	// wp_remote_retrieve_header() returns a STRING for a single header
135	// but an ARRAY when the header appears more than once (common behind
136	// CDNs / proxies, or nginx with multiple add_header lines). Casting
137	// an array with (string) emits an "Array to string conversion"
138	// warning AND flattens to the literal "Array", so the immutable
139	// check below silently false-negatives. Normalize array → string
140	// first. (FBS-82141)
141	$raw = wp_remote_retrieve_header( $resp, 'cache-control' );
142	$cache_control = is_array( $raw ) ? implode( ', ', $raw ) : (string) $raw;
143	$active = false !== stripos( $cache_control, 'immutable' );
144	set_transient( 'xspeed_browser_cache_probe', $active ? 1 : 0, 5 * MINUTE_IN_SECONDS );
145	return $active;
146	}
147
148	public static function nginx_snippet( array $opts = array() ): string {
149	$asset = (int) ( $opts['asset_ttl'] ?? self::DEFAULT_ASSET_TTL );
150	$html = (int) ( $opts['html_ttl'] ?? self::DEFAULT_HTML_TTL );
151	return implode(
152	"\n",
153	array(
154	'location ~* \.(css\|js\|jpg\|jpeg\|png\|gif\|webp\|avif\|svg\|ico\|woff2\|woff\|ttf\|otf\|eot\|mp4\|webm\|mp3\|ogg)$ {',
155	' expires ' . $asset . 's;',
156	' add_header Cache-Control "public, max-age=' . $asset . ', immutable";',
157	'}',
158	'location ~* \.html$ {',
159	' expires ' . $html . 's;',
160	' add_header Cache-Control "public, max-age=' . $html . '";',
161	'}',
162	)
163	);
164	}
165	}
166