activitypub / integration / class-wp-rest-cache.php

class-wp-rest-cache.php in ActivityPub 7.8.4, at integration/class-wp-rest-cache.php

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1	<?php
2	/**
3	* WP REST Cache integration file.
4	*
5	* This file contains code for caching ActivityPub REST requests.
6	*
7	* Copyright (C) 2025 Epiphyt
8	* Original code: https://epiph.yt/en/blog/2025/accidental-ddos-through-activitypub-plugin/
9	*
10	* Portions of this code are adapted from GPL v2 licensed code.
11	* As such, you may also redistribute and/or modify those portions under the terms of
12	* the GNU General Public License as published by the Free Software Foundation.
13	*
14	* https://www.gnu.org/licenses/gpl-2.0.html
15	*
16	* @package Activitypub
17	*/
18
19	namespace Activitypub\Integration;
20
21	use Activitypub\Collection\Outbox;
22	use Activitypub\Comment;
23	use WP_Rest_Cache_Plugin\Includes\Caching\Caching;
24
25	/**
26	* Compatibility with the WP REST Cache plugin.
27	*
28	* @see https://wordpress.org/plugins/wp-rest-cache/
29	*/
30	class WP_Rest_Cache {
31	/**
32	* Initialize the class, registering WordPress hooks.
33	*/
34	public static function init() {
35	\add_filter( 'wp_rest_cache/allowed_endpoints', array( self::class, 'add_activitypub_endpoints' ) );
36	\add_filter( 'wp_rest_cache/determine_object_type', array( self::class, 'set_object_type' ), 10, 4 );
37	\add_filter( 'wp_rest_cache/is_single_item', array( self::class, 'set_is_single_item' ), 10, 3 );
38	\add_action( 'transition_post_status', array( self::class, 'transition_post_status' ), 10, 3 );
39	\add_action( 'transition_comment_status', array( self::class, 'transition_comment_status' ), 10, 3 );
40	}
41
42	/**
43	* Add ActivityPub endpoints to the list of allowed endpoints.
44	*
45	* @param array $endpoints List of allowed endpoints.
46	*
47	* @return array Filtered list of allowed endpoints.
48	*/
49	public static function add_activitypub_endpoints( $endpoints ) {
50	$endpoints[ ACTIVITYPUB_REST_NAMESPACE ] = array( 'actors', 'collections', 'comments', 'interactions', 'nodeinfo', 'posts', 'users' );
51
52	return $endpoints;
53	}
54
55	/**
56	* Set whether the cache represents a single item.
57	*
58	* Always return false for ActivityPub endpoints, since cache entries cannot be flushed otherwise.
59	*
60	* @param bool $is_single Whether the current cache represents a single item.
61	* @param mixed $data Data to cache.
62	* @param string $uri Request URI.
63	*
64	* @return bool Whether the cache represents a single item.
65	*/
66	public static function set_is_single_item( $is_single, $data, $uri ) {
67	if ( self::is_activitypub_endpoint( $uri ) ) {
68	return false;
69	}
70
71	return $is_single;
72	}
73
74	/**
75	* Set object type for ActivityPub.
76	*
77	* @param string $object_type Object type.
78	* @param string $cache_key Object key.
79	* @param mixed $data Data to cache.
80	* @param string $uri Request URI.
81	*
82	* @return string Updated object type.
83	*/
84	public static function set_object_type( $object_type, $cache_key, $data, $uri ) {
85	if ( self::is_activitypub_endpoint( $uri ) ) {
86	return 'ActivityPub';
87	}
88
89	return $object_type;
90	}
91
92	/**
93	* Reset cache by transition post status.
94	*
95	* @param string $new_status New post status.
96	* @param string $old_status Old post status.
97	* @param \WP_Post $post Post object.
98	*/
99	public static function transition_post_status( $new_status, $old_status, $post ) {
100	if ( 'publish' !== $new_status && 'publish' !== $old_status ) {
101	return;
102	}
103
104	$post_types = \get_option( 'activitypub_support_post_types', array() );
105	$post_types[] = Outbox::POST_TYPE;
106
107	if ( ! \in_array( $post->post_type, $post_types, true ) ) {
108	return;
109	}
110
111	Caching::get_instance()->delete_object_type_caches( 'ActivityPub' );
112	}
113
114	/**
115	* Reset cache by transition comment status.
116	*
117	* @param string $new_status The new comment status.
118	* @param string $old_status The old comment status.
119	* @param \WP_Comment $comment Comment object.
120	*/
121	public static function transition_comment_status( $new_status, $old_status, $comment ) {
122	if ( 'approved' !== $new_status && 'approved' !== $old_status ) {
123	return;
124	}
125
126	$comment_types = Comment::get_comment_type_slugs();
127	$comment_types[] = 'comment';
128
129	if ( ! \in_array( $comment->comment_type ?: 'comment', $comment_types, true ) ) {
130	return;
131	}
132
133	Caching::get_instance()->delete_object_type_caches( 'ActivityPub' );
134	}
135
136	/**
137	* Test, whether the current endpoint is an ActivityPub endpoint.
138	*
139	* @param string $uri URI to test.
140	*
141	* @return bool Whether the current endpoint is an ActivityPub endpoint.
142	*/
143	private static function is_activitypub_endpoint( $uri ) {
144	$search = '/' . ACTIVITYPUB_REST_NAMESPACE . '/';
145
146	return \str_contains( $uri, $search ) \|\| \str_contains( $uri, 'rest_route=' . \rawurlencode( $search ) );
147	}
148	}
149