404-solution / includes / stats / StatsDashboardSnapshotCache.php

StatsDashboardSnapshotCache.php in 404 Solution trunk, at includes/stats/StatsDashboardSnapshotCache.php

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1	<?php
2
3	if (!defined('ABSPATH')) {
4	exit;
5	}
6
7	/**
8	* Owns the dashboard stats snapshot cache and stale-fallback refresh policy.
9	*/
10	class ABJ_404_Solution_StatsDashboardSnapshotCache {
11
12	/** @var int Retention for dashboard stats snapshot payload. */
13	const STATS_DASHBOARD_CACHE_TTL_SECONDS = 86400;
14	/** @var int Minimum time between full stats snapshot recomputes. */
15	const STATS_DASHBOARD_REFRESH_COOLDOWN_SECONDS = 30;
16
17	/** @var ABJ_404_Solution_StatsReadRepository */
18	private $statsReadRepository;
19	/** @var ABJ_404_Solution_StatsRefreshLock */
20	private $refreshLock;
21	/** @var ABJ_404_Solution_Logging */
22	private $logger;
23
24	/**
25	* @param ABJ_404_Solution_StatsReadRepository $statsReadRepository
26	* @param ABJ_404_Solution_StatsRefreshLock $refreshLock
27	* @param ABJ_404_Solution_Logging $logging
28	*/
29	public function __construct(
30	ABJ_404_Solution_StatsReadRepository $statsReadRepository,
31	ABJ_404_Solution_StatsRefreshLock $refreshLock,
32	$logging
33	) {
34	$this->statsReadRepository = $statsReadRepository;
35	$this->refreshLock = $refreshLock;
36	$this->logger = $logging;
37	}
38
39	/**
40	* @param bool $allowStale
41	* @return array{refreshed_at:int,hash:string,data:array<string, mixed>}
42	*/
43	public function getStatsDashboardSnapshot($allowStale = true) {
44	$cached = $this->getFromCache();
45	if ($cached !== null && !empty($cached['data']) && $allowStale) {
46	return $cached;
47	}
48
49	return $this->refresh(false);
50	}
51
52	/**
53	* @param bool $force
54	* @return array{refreshed_at:int,hash:string,data:array<string, mixed>}
55	*/
56	public function refresh($force = false) {
57	$cached = $this->getFromCache();
58	$hasCachedData = ($cached !== null && !empty($cached['data']));
59	$cachedAge = $hasCachedData ? max(0, abj_clock()->now() - (is_scalar($cached['refreshed_at'] ?? 0) ? intval($cached['refreshed_at'] ?? 0) : 0)) : PHP_INT_MAX;
60
61	if (!$force && $hasCachedData && $cachedAge < self::STATS_DASHBOARD_REFRESH_COOLDOWN_SECONDS) {
62	return $cached;
63	}
64
65	$lockKey = 'stats-dashboard:' . $this->getCacheKey();
66	$lockAcquired = $this->refreshLock->acquire($lockKey);
67	if (!$lockAcquired && $hasCachedData) {
68	return $cached;
69	}
70
71	try {
72	$data = $this->statsReadRepository->buildStatsDashboardSnapshotData();
73	$payload = array(
74	'refreshed_at' => abj_clock()->now(),
75	'hash' => $this->hash($data),
76	'data' => $data,
77	);
78	if (function_exists('set_transient')) {
79	set_transient($this->getCacheKey(), $payload, self::STATS_DASHBOARD_CACHE_TTL_SECONDS);
80	}
81	return $payload;
82	} catch (Throwable $e) {
83	if ($hasCachedData) {
84	$this->logger->debugMessage(__FUNCTION__ . ' failed to recompute stats snapshot; returning cached snapshot. Error: ' . $e->getMessage());
85	return $cached;
86	}
87	throw $e;
88	} finally {
89	if ($lockAcquired) {
90	$this->refreshLock->release($lockKey);
91	}
92	}
93	}
94
95	/** @return array{refreshed_at:int,hash:string,data:array<string, mixed>}\|null */
96	private function getFromCache() {
97	if (!function_exists('get_transient')) {
98	return null;
99	}
100	$cached = get_transient($this->getCacheKey());
101	if (!is_array($cached)) {
102	return null;
103	}
104	if (!array_key_exists('data', $cached) \|\| !is_array($cached['data'])) {
105	return null;
106	}
107	$data = array();
108	foreach ($cached['data'] as $key => $value) {
109	if (is_string($key)) {
110	$data[$key] = $value;
111	}
112	}
113
114	return array(
115	'refreshed_at' => is_scalar($cached['refreshed_at'] ?? null) ? intval($cached['refreshed_at']) : 0,
116	'hash' => is_string($cached['hash'] ?? null) ? $cached['hash'] : '',
117	'data' => $data,
118	);
119	}
120
121	/** @return string */
122	private function getCacheKey(): string {
123	$blogId = 1;
124	if (function_exists('get_current_blog_id')) {
125	$blogId = absint(get_current_blog_id());
126	if ($blogId <= 0) {
127	$blogId = 1;
128	}
129	}
130	return 'abj404_stats_dashboard_snapshot_v1_' . $blogId;
131	}
132
133	/**
134	* @param array<string, mixed> $data
135	* @return string
136	*/
137	private function hash($data) {
138	$encoded = function_exists('wp_json_encode') ? wp_json_encode($data) : json_encode($data);
139	if (!is_string($encoded)) {
140	$encoded = '';
141	}
142	return md5($encoded);
143	}
144	}
145