← All changes | includes/seo/class-sitemap-generator.php +1269 -119 2.7.0 → 2.14.1 View file →

		@@ -144,8 +144,98 @@
144	144	*/
145	145	public const REGENERATION_ERROR_OPTION = 'thinkrank_sitemap_regeneration_error';
146	146
147	147	/**
	148	+ * Delivery modes accepted by the `delivery_mode` setting.
	149	+ *
	150	+ * Mirrors LLMs_Txt_Manager::DELIVERY_MODES, which solved the same problem
	151	+ * for llms.txt. `auto` is the only value a site should normally need.
	152	+ *
	153	+ * @since 2.9.0
	154	+ * @var string[]
	155	+ */
	156	+ public const DELIVERY_MODES = ['auto', 'static', 'dynamic'];
	157	+
	158	+ /**
	159	+ * Cache group for documents rendered on the dynamic path.
	160	+ *
	161	+ * @since 2.9.0
	162	+ * @var string
	163	+ */
	164	+ private const DYNAMIC_CACHE_PREFIX = 'thinkrank_sitemap_doc_';
	165	+
	166	+ /**
	167	+ * How long a dynamically rendered document is cached.
	168	+ *
	169	+ * Invalidated by content and settings changes through
	170	+ * {@see self::flush_dynamic_cache()}, so this is only the backstop for a
	171	+ * change nothing hooked.
	172	+ *
	173	+ * @since 2.9.0
	174	+ * @var int
	175	+ */
	176	+ private const DYNAMIC_CACHE_TTL = 12 * HOUR_IN_SECONDS;
	177	+
	178	+ /**
	179	+ * How long the render lock is held before it is assumed abandoned.
	180	+ *
	181	+ * Long enough for a large site's full build, short enough that a request
	182	+ * killed mid-build does not lock the endpoint out for meaningfully long.
	183	+ *
	184	+ * @since 2.9.0
	185	+ * @var int
	186	+ */
	187	+ private const RENDER_LOCK_TTL = 60;
	188	+
	189	+ /**
	190	+ * Cached stand-in for "this site does not publish that name".
	191	+ *
	192	+ * published_document_names() lists what the configuration *could* produce,
	193	+ * but a child whose type is excluded produces nothing. Without a negative
	194	+ * entry those names miss the cache forever, so every request for one
	195	+ * rebuilt the entire sitemap — the same cost the positive cache exists to
	196	+ * avoid, on a public endpoint (#754 review).
	197	+ *
	198	+ * @since 2.9.0
	199	+ * @var string
	200	+ */
	201	+ private const ABSENT_MARKER = "\0thinkrank-absent";
	202	+
	203	+ /**
	204	+ * How many times, and how long, a losing request waits for the winner.
	205	+ *
	206	+ * Bounded at roughly a second in total: past that, building a second copy
	207	+ * costs less than making a crawler wait.
	208	+ *
	209	+ * @since 2.9.0
	210	+ * @var int
	211	+ */
	212	+ private const RENDER_LOCK_WAIT_ATTEMPTS = 4;
	213	+
	214	+ /**
	215	+ * @since 2.9.0
	216	+ * @var int
	217	+ */
	218	+ private const RENDER_LOCK_WAIT_MICROSECONDS = 250000;
	219	+
	220	+ /**
	221	+ * Where generated documents go instead of disk, when set.
	222	+ *
	223	+ * Every sitemap document this class produces — segments, the index, the
	224	+ * single flat file and local-sitemap.xml — is published through the one
	225	+ * writer, {@see self::save_sitemap_to_file()}. Swapping that writer for a
	226	+ * collector is therefore all it takes to render the same bytes without a
	227	+ * filesystem, which is what dynamic delivery needs (#752). Doing it here
	228	+ * rather than duplicating the build pipeline is deliberate: a second
	229	+ * pipeline would drift from this one, and the index in particular is
	230	+ * assembled from whatever the children actually produced.
	231	+ *
	232	+ * @since 2.9.0
	233	+ * @var callable|null
	234	+ */
	235	+ private $document_sink = null;
	236	+
	237	+ /**
148	238	* Transient guarding against two generations running at once. Shared with
149	239	* Sitemap_Endpoint's manual generate route so an automatic rebuild and a
150	240	* manual one cannot write the same files concurrently.
151	241	*
		@@ -161,8 +251,33 @@
161	251	* @var int
162	252	*/
163	253	private const TERM_WALK_CHUNK = 1000;
164	254
	255	+ /**
	256	+ * Exception code for an automatic rebuild stopped short of the memory limit.
	257	+ *
	258	+ * @since 2.10.1
	259	+ * @var int
	260	+ */
	261	+ private const MEMORY_ABORT_CODE = 4290;
	262	+
	263	+ /**
	264	+ * Whether the chunked walks should stop before the memory limit. Only on
	265	+ * for automatic rebuilds, whose failure is recorded and retried.
	266	+ *
	267	+ * @since 2.10.1
	268	+ * @var bool
	269	+ */
	270	+ private bool $memory_guard = false;
	271	+
	272	+ /**
	273	+ * Largest memory cost of one walked chunk in this rebuild, in bytes.
	274	+ *
	275	+ * @since 2.10.1
	276	+ * @var int
	277	+ */
	278	+ private int $walk_chunk_cost = 0;
	279	+
165	280	private array $sitemap_types = [
166	281	'posts' => [
167	282	'name' => 'Posts',
168	283	'post_types' => ['post'],
		@@ -189,25 +304,29 @@
189	304	]
190	305	];
191	306
192	307	/**
	308	+ * The generator the content-change listeners share, built on the first
	309	+ * change of a request.
	310	+ *
	311	+ * @since 2.10.1
	312	+ * @var self|null
	313	+ */
	314	+ private static ?self $listener = null;
	315	+
	316	+ /**
193	317	* Constructor
194	318	*
195	319	* @since 1.0.0
	320	+ * @since 2.10.1 Registers no hooks, whatever `$register_hooks` says. The
	321	+ * content-change listeners are registered once, at bootstrap,
	322	+ * by register_content_listeners().
196	323	*
197		- * @param bool $register_hooks Optional. Whether to register the auto-generation
198		- * hooks. Pass false for a read-only instance built
199		- * solely to query settings — the hooks are bound to
200		- * `$this`, so a second hook-registering instance
201		- * would run `handle_content_change()` twice per save.
	324	+ * @param bool $register_hooks Unused since 2.10.1; kept so existing callers,
	325	+ * Pro's included, keep working.
202	326	*/
203	327	public function __construct(bool $register_hooks = true) {
204	328	parent::__construct('sitemap');
205		-
206		- // Initialize auto-generation hooks
207		- if ($register_hooks) {
208		- $this->init_auto_generation_hooks();
209		- }
210	329	}
211	330
212	331	/**
213	332	* Filter the args of a sitemap post query.
		@@ -251,34 +370,154 @@
251	370	return (array) apply_filters('thinkrank_sitemap_term_query_args', $args);
252	371	}
253	372
254	373	/**
255		- * Initialize WordPress hooks for auto-generation
	374	+ * Register the content-change listeners that queue an automatic rebuild.
256	375	*
257		- * @since 1.0.0
	376	+ * Called once per request, at plugin bootstrap, next to the WP-Cron
	377	+ * listeners that run the rebuild these queue (both in
	378	+ * Plugin::register_sitemap_cron_listeners(), on plugins_loaded). The
	379	+ * constructor used to register them, so they existed only in a request
	380	+ * that happened to build a generator: the REST endpoint, the setup wizard,
	381	+ * an MCP ability. Block-editor saves go through REST and were heard. A
	382	+ * scheduled post published by WP-Cron, Quick Edit, the classic editor and
	383	+ * WP-CLI were not, so the post stayed out of the sitemap with nothing
	384	+ * pending to recover it (#824). Each instance also added its own set, so
	385	+ * one REST save ran the handlers once per generator built.
	386	+ *
	387	+ * The generator is built on the first change and shared for the rest of
	388	+ * the request, so a bulk edit does not construct one per post.
	389	+ *
	390	+ * @since 2.10.1
258	391	* @return void
259	392	*/
260		- private function init_auto_generation_hooks(): void {
261		- // Content change hooks - use priority 20 to run after other plugins
262		- add_action('save_post', [$this, 'handle_content_change'], 20, 2);
263		- add_action('delete_post', [$this, 'handle_content_deletion'], 20);
264		- add_action('wp_trash_post', [$this, 'handle_content_deletion'], 20);
265		- add_action('untrash_post', [$this, 'handle_content_change_by_id'], 20);
	393	+ public static function register_content_listeners(): void {
	394	+ // Priority 20, to run after other plugins.
	395	+ add_action('save_post', static function (int $post_id, \WP_Post $post): void {
	396	+ self::listener()->handle_content_change($post_id, $post);
	397	+ }, 20, 2);
	398	+ add_action('delete_post', static function (int $post_id): void {
	399	+ self::listener()->handle_content_deletion($post_id);
	400	+ }, 20);
	401	+ add_action('wp_trash_post', static function (int $post_id): void {
	402	+ self::listener()->handle_content_deletion($post_id);
	403	+ }, 20);
	404	+ add_action('untrash_post', static function (int $post_id): void {
	405	+ self::listener()->handle_content_change_by_id($post_id);
	406	+ }, 20);
266	407
267		- // Taxonomy change hooks
268		- add_action('created_term', [$this, 'handle_taxonomy_change'], 20, 3);
269		- add_action('edited_term', [$this, 'handle_taxonomy_change'], 20, 3);
270		- add_action('delete_term', [$this, 'handle_taxonomy_change'], 20, 3);
	408	+ foreach (['created_term', 'edited_term', 'delete_term'] as $hook) {
	409	+ add_action($hook, static function (int $term_id, int $tt_id, string $taxonomy): void {
	410	+ self::listener()->handle_taxonomy_change($term_id, $tt_id, $taxonomy);
	411	+ }, 20, 3);
	412	+ }
271	413
272		- // NOTE: the WP-Cron regeneration listeners (thinkrank_regenerate_sitemap
273		- // and thinkrank_regenerate_sitemap_settings) are registered at plugin
274		- // bootstrap (Plugin::register_sitemap_cron_listeners(), on plugins_loaded)
275		- // rather than here. A cron run never builds this class via the REST
276		- // endpoint (no rest_api_init), so registering them in the constructor
277		- // would leave the scheduled events with no listener at cron time.
	414	+ // The sitemap leaves out what the robots tag noindexes and what
	415	+ // ThinkRank redirects (#911), so a change to either decides what the
	416	+ // published files should list. Neither is a post or term save, and
	417	+ // without these the files kept the old answer until unrelated content
	418	+ // changed.
	419	+ foreach (self::ROBOTS_SETTINGS_OPTIONS as $option) {
	420	+ add_action('update_option_' . $option, static function ($old_value, $value): void {
	421	+ self::handle_robots_settings_change($old_value, $value);
	422	+ }, 20, 2);
	423	+ add_action('add_option_' . $option, static function ($name, $value): void {
	424	+ self::handle_robots_settings_change([], $value);
	425	+ }, 20, 2);
	426	+ }
	427	+
	428	+ add_action('thinkrank_object_redirect_saved', static function (): void {
	429	+ self::listener()->schedule_regeneration();
	430	+ }, 20, 0);
278	431	}
279	432
280	433	/**
	434	+ * Options holding robots directives the sitemap's item filter reads.
	435	+ *
	436	+ * @since 2.15.0
	437	+ * @var string[]
	438	+ */
	439	+ private const ROBOTS_SETTINGS_OPTIONS = [
	440	+ 'thinkrank_global_seo_settings',
	441	+ 'thinkrank_global_robot_meta_settings',
	442	+ ];
	443	+
	444	+ /**
	445	+ * Queue a rebuild when a saved robots setting changes a noindex decision.
	446	+ *
	447	+ * Both options carry far more than robots directives (titles, schema,
	448	+ * feature switches), so only a change to a noindex outcome rebuilds.
	449	+ *
	450	+ * @since 2.15.0
	451	+ *
	452	+ * @param mixed $old_value Previous option value.
	453	+ * @param mixed $value New option value.
	454	+ * @return void
	455	+ */
	456	+ public static function handle_robots_settings_change($old_value, $value): void {
	457	+ if (self::noindex_fingerprint($old_value) === self::noindex_fingerprint($value)) {
	458	+ return;
	459	+ }
	460	+
	461	+ // The matrix memoises the option for the request, and a rebuild that
	462	+ // runs in this request must read the value just saved.
	463	+ Content_Type_Settings::flush_cache();
	464	+
	465	+ self::listener()->schedule_regeneration();
	466	+ }
	467	+
	468	+ /**
	469	+ * The noindex decisions a robots option makes, keyed by what they apply to.
	470	+ *
	471	+ * Reads both shapes: the flat site-wide directives, and the per-entity
	472	+ * rows, where a row's directives apply only while its robots switch is on.
	473	+ * A row that is on but stores no `noindex` key changes nothing, matching
	474	+ * the array_merge() the robots tag does.
	475	+ *
	476	+ * @since 2.15.0
	477	+ *
	478	+ * @param mixed $value Option value.
	479	+ * @return array<string, bool|null>
	480	+ */
	481	+ private static function noindex_fingerprint($value): array {
	482	+ if (!is_array($value)) {
	483	+ return [];
	484	+ }
	485	+
	486	+ $decisions = [];
	487	+
	488	+ if (array_key_exists('noindex', $value) && !is_array($value['noindex'])) {
	489	+ $decisions['*'] = !empty($value['noindex']);
	490	+ }
	491	+
	492	+ foreach ($value as $key => $row) {
	493	+ if (!is_array($row)) {
	494	+ continue;
	495	+ }
	496	+
	497	+ $robots = $row['robots_meta'] ?? null;
	498	+
	499	+ $decisions[(string) $key] = !empty($row['robots_meta_enabled']) && is_array($robots) && array_key_exists('noindex', $robots)
	500	+ ? !empty($robots['noindex'])
	501	+ : null;
	502	+ }
	503	+
	504	+ ksort($decisions);
	505	+
	506	+ return $decisions;
	507	+ }
	508	+
	509	+ /**
	510	+ * The generator the content-change listeners share.
	511	+ *
	512	+ * @since 2.10.1
	513	+ * @return self
	514	+ */
	515	+ private static function listener(): self {
	516	+ return self::$listener ??= new self(false);
	517	+ }
	518	+
	519	+ /**
281	520	* Generate XML sitemap
282	521	*
283	522	* @since 1.0.0
284	523	*
		@@ -452,8 +691,15 @@
452	691	]
453	692	],
454	693	'use_sitemap_index' => false,
455	694
	695	+ // How the sitemap reaches crawlers. 'auto' keeps the historical
	696	+ // behaviour wherever the web root is writable, and only falls back
	697	+ // to serving the sitemap from PHP where writing a file is
	698	+ // impossible — previously a hard failure with nothing served
	699	+ // (#752).
	700	+ 'delivery_mode' => 'auto',
	701	+
456	702	// General Settings
457	703	'links_per_sitemap' => 1000,
458	704	'include_images' => true,
459	705	'include_featured_images' => false,
		@@ -519,8 +765,16 @@
519	765	if (array_key_exists('styling_logo_url', $sanitized)) {
520	766	$sanitized['styling_logo_url'] = esc_url_raw((string) $sanitized['styling_logo_url']);
521	767	}
522	768
	769	+ // A mode this build cannot act on has to be stored as the fallback
	770	+ // rather than kept verbatim, or get-sitemap-settings reports a delivery
	771	+ // mode the site does not actually apply.
	772	+ if (array_key_exists('delivery_mode', $sanitized)) {
	773	+ $mode = sanitize_key((string) $sanitized['delivery_mode']);
	774	+ $sanitized['delivery_mode'] = in_array($mode, self::DELIVERY_MODES, true) ? $mode : 'auto';
	775	+ }
	776	+
523	777	return $sanitized;
524	778	}
525	779
526	780	/**
		@@ -538,8 +792,15 @@
538	792	'title' => 'Enable Sitemap',
539	793	'description' => 'Generate XML sitemap for search engines',
540	794	'default' => true
541	795	],
	796	+ 'delivery_mode' => [
	797	+ 'type' => 'string',
	798	+ 'title' => 'Sitemap Delivery',
	799	+ 'description' => 'How the sitemap is served: auto picks static when the WordPress root is writable and dynamic when it is not, static writes files to the web root, dynamic serves the sitemap from WordPress with no files written',
	800	+ 'enum' => self::DELIVERY_MODES,
	801	+ 'default' => 'auto'
	802	+ ],
542	803	'include_posts' => [
543	804	'type' => 'boolean',
544	805	'title' => 'Include Posts',
545	806	'description' => 'Include blog posts in sitemap',
		@@ -762,8 +1023,11 @@
762	1023	// well-bounded routine with no ceiling (#402).
763	1024	$total = count($all_ids);
764	1025
765	1026	for ($offset = 0; $offset < $total; $offset += self::ID_WALK_CHUNK) {
	1027	+ $this->assert_memory_headroom();
	1028	+ $chunk_start = memory_get_usage(true);
	1029	+
766	1030	$chunk = array_slice($all_ids, $offset, self::ID_WALK_CHUNK);
767	1031
768	1032	$posts = get_posts($this->filter_query_args([
769	1033	'post_type' => $post_types,
		@@ -772,8 +1036,12 @@
772	1036	'post__in' => $chunk,
773	1037	'orderby' => 'post__in', // preserve the resolved order
774	1038	]));
775	1039
	1040	+ // get_featured_image() hydrates each featured image under the
	1041	+ // attachment's own ID, which the chunk's post IDs do not reach.
	1042	+ $attachment_ids = [];
	1043	+
776	1044	foreach ($posts as $post) {
777	1045	if ($this->should_include_in_sitemap($post, $settings)) {
778	1046	/**
779	1047	* Filter a sitemap entry's permalink.
		@@ -794,14 +1062,25 @@
794	1062	$priority = $this->calculate_intelligent_priority($post, $post->post_type);
795	1063	$changefreq = $this->calculate_change_frequency($post, $post->post_type);
796	1064	$images = $this->extract_post_images($post, $settings);
797	1065
	1066	+ $thumbnail_id = (int) get_post_thumbnail_id($post);
	1067	+ if ($thumbnail_id > 0) {
	1068	+ $attachment_ids[] = $thumbnail_id;
	1069	+ }
	1070	+
798	1071	yield $this->generate_url_entry($url, $lastmod, $priority, $changefreq, $images);
799	1072	}
800	1073	}
801	1074
802		- // Free the hydrated chunk before loading the next one.
	1075	+ // Free the hydrated chunk before loading the next one — including
	1076	+ // the copies get_posts() left in the runtime object cache.
803	1077	unset($posts);
	1078	+ $this->release_walk_memory(
	1079	+ $chunk_start,
	1080	+ $this->chunk_post_cache_groups($post_types),
	1081	+ array_merge($chunk, $attachment_ids)
	1082	+ );
804	1083	}
805	1084	}
806	1085
807	1086	/**
		@@ -861,8 +1140,11 @@
861	1140	// Same moving window as the post walk above, for the same reason.
862	1141	$total = count($all_ids);
863	1142
864	1143	for ($offset = 0; $offset < $total; $offset += self::TERM_WALK_CHUNK) {
	1144	+ $this->assert_memory_headroom();
	1145	+ $chunk_start = memory_get_usage(true);
	1146	+
865	1147	$chunk = array_slice($all_ids, $offset, self::TERM_WALK_CHUNK);
866	1148
867	1149	$terms = get_terms($this->filter_term_query_args([
868	1150	'taxonomy' => $taxonomy,
		@@ -875,12 +1157,12 @@
875	1157	continue;
876	1158	}
877	1159
878	1160	foreach ($terms as $term) {
879		- // A term the user marked noindex must not be advertised in the
880		- // sitemap: the robots tag now honours term meta, so listing it
881		- // here would have the sitemap contradict the page's own tag.
882		- if ($this->term_is_noindexed((int) $term->term_id)) {
	1161	+ // A term whose archive says noindex (its own override or its
	1162	+ // taxonomy's), or that redirects, must not be advertised: the
	1163	+ // sitemap would contradict the page's own signal (#911).
	1164	+ if (!Indexability::is_indexable_term($term)) {
883	1165	continue;
884	1166	}
885	1167
886	1168	$url = get_term_link($term);
		@@ -891,8 +1173,9 @@
891	1173	}
892	1174	}
893	1175
894	1176	unset($terms);
	1177	+ $this->release_walk_memory($chunk_start, ['terms', 'term_meta'], $chunk);
895	1178	}
896	1179	}
897	1180
898	1181	/**
		@@ -1184,14 +1467,15 @@
1184	1467	if (is_wp_error($all_terms)) {
1185	1468	return [];
1186	1469	}
1187	1470
1188		- // Drop terms the user marked noindex. This path feeds the single general
1189		- // sitemap while collect_taxonomy_entries_iter() feeds the segmented ones,
1190		- // so both need the filter or the two disagree about the same term.
	1471	+ // Drop terms that are not indexable destinations. This path feeds the
	1472	+ // single general sitemap while collect_taxonomy_entries_iter() feeds
	1473	+ // the segmented ones, so both need the filter or the two disagree about
	1474	+ // the same term.
1191	1475	$all_terms = array_values(array_filter(
1192	1476	$all_terms,
1193		- fn($term) => !$this->term_is_noindexed((int) $term->term_id)
	1477	+ static fn($term) => $term instanceof \WP_Term && Indexability::is_indexable_term($term)
1194	1478	));
1195	1479
1196	1480	// Group terms by taxonomy
1197	1481	return $this->group_terms_by_taxonomy($all_terms);
		@@ -1373,17 +1657,16 @@
1373	1657	if (!in_array($post->post_status, ['publish', 'private'], true)) {
1374	1658	return false;
1375	1659	}
1376	1660
1377		- // Check if post overrides robots and sets noindex.
1378		- if ((bool) get_post_meta($post->ID, '_thinkrank_robots_meta_enabled', true)) {
1379		- $raw = get_post_meta($post->ID, '_thinkrank_robots_meta', true);
1380		- if (is_string($raw) && $raw !== '') {
1381		- $robots = json_decode($raw, true);
1382		- if (is_array($robots) && !empty($robots['noindex'])) {
1383		- return false;
1384		- }
1385		- }
	1661	+ // A URL whose page says noindex, or that ThinkRank redirects, is not a
	1662	+ // destination. Only the per-post noindex used to be read here, so a
	1663	+ // post type set to No-index still had every item listed, and redirected
	1664	+ // posts were submitted as "Page with redirect" (#911). The password
	1665	+ // check stays with the setting above: listing protected posts is a
	1666	+ // choice this sitemap has always offered.
	1667	+ if (Indexability::is_post_noindexed($post) || Indexability::is_post_redirected($post)) {
	1668	+ return false;
1386	1669	}
1387	1670
1388	1671	return true;
1389	1672	}
		@@ -1422,35 +1705,8 @@
1422	1705	return $ids;
1423	1706	}
1424	1707
1425	1708	/**
1426		- * Whether a term carries an explicit noindex override.
1427		- *
1428		- * Mirrors the post-side check in should_include_post(); terms store the same
1429		- * `_thinkrank_robots_meta_enabled` / `_thinkrank_robots_meta` keys, written
1430		- * by the update-term-seo ability and by the SEO importer.
1431		- *
1432		- * @since 1.31.0
1433		- *
1434		- * @param int $term_id Term to test.
1435		- * @return bool True when the term is marked noindex.
1436		- */
1437		- private function term_is_noindexed(int $term_id): bool {
1438		- if (!(bool) get_term_meta($term_id, '_thinkrank_robots_meta_enabled', true)) {
1439		- return false;
1440		- }
1441		-
1442		- $raw = get_term_meta($term_id, '_thinkrank_robots_meta', true);
1443		- if (!is_string($raw) || $raw === '') {
1444		- return false;
1445		- }
1446		-
1447		- $robots = json_decode($raw, true);
1448		-
1449		- return is_array($robots) && !empty($robots['noindex']);
1450		- }
1451		-
1452		- /**
1453	1709	* Count total URLs in sitemap
1454	1710	*
1455	1711	* @since 1.0.0
1456	1712	*
		@@ -1729,8 +1985,14 @@
1729	1985	* @param string $source Either 'content' or 'settings'.
1730	1986	* @return void
1731	1987	*/
1732	1988	private function mark_regeneration_pending(string $source): void {
	1989	+ // Whatever made the static files stale made the rendered ones stale
	1990	+ // too. Invalidating here rather than only on the rebuild keeps the two
	1991	+ // delivery modes reacting to exactly the same triggers, which is the
	1992	+ // only way a dynamic site stays as fresh as a static one (#752).
	1993	+ $this->flush_dynamic_cache();
	1994	+
1733	1995	$pending = get_option(self::REGENERATION_PENDING_OPTION, []);
1734	1996	$pending = is_array($pending) ? $pending : [];
1735	1997
1736	1998	$since = !empty($pending['since']) ? (int) $pending['since'] : time();
		@@ -1736,11 +1998,13 @@
1736	1998	$since = !empty($pending['since']) ? (int) $pending['since'] : time();
1737	1999	$current = isset($pending['source']) ? (string) $pending['source'] : '';
1738	2000	$source = ($current === 'settings' || $source === 'settings') ? 'settings' : 'content';
1739	2001
	2002	+ // Merged so the bookkeeping a rebuild keeps on the marker (`started`,
	2003	+ // `memory_limit`) survives an edit made while it is outstanding.
1740	2004	update_option(
1741	2005	self::REGENERATION_PENDING_OPTION,
1742		- [
	2006	+ array_merge($pending, [
1743	2007	'since' => $since,
1744	2008	'source' => $source,
1745	2009	'attempts' => !empty($pending['attempts']) ? (int) $pending['attempts'] : 0,
1746	2010	'next_attempt' => !empty($pending['next_attempt'])
		@@ -1748,9 +2012,9 @@
1748	2012	: time() + self::REGENERATION_TAKEOVER_GRACE,
1749	2013	// Bumped on every change so a rebuild can tell whether the edit
1750	2014	// it started for is still the newest one outstanding.
1751	2015	'revision' => (!empty($pending['revision']) ? (int) $pending['revision'] : 0) + 1,
1752		- ],
	2016	+ ]),
1753	2017	true
1754	2018	);
1755	2019	}
1756	2020
		@@ -1796,8 +2060,18 @@
1796	2060	$revision !== null
1797	2061	&& is_array($pending)
1798	2062	&& (int) ($pending['revision'] ?? 0) !== $revision
1799	2063	) {
	2064	+ // This attempt succeeded, so drop what it claimed: the newer change
	2065	+ // waits the grace a fresh edit gets, not a failure backoff it never
	2066	+ // earned. Not zero: that edit queued its own debounced event, and
	2067	+ // a marker due at once had the next admin request rebuild in its
	2068	+ // shutdown and the event rebuild again seconds later.
	2069	+ unset($pending['started'], $pending['memory_limit']);
	2070	+ $pending['attempts'] = 0;
	2071	+ $pending['next_attempt'] = time() + self::REGENERATION_TAKEOVER_GRACE;
	2072	+
	2073	+ update_option(self::REGENERATION_PENDING_OPTION, $pending, true);
1800	2074	return;
1801	2075	}
1802	2076
1803	2077	delete_option(self::REGENERATION_PENDING_OPTION);
		@@ -1803,8 +2077,69 @@
1803	2077	delete_option(self::REGENERATION_PENDING_OPTION);
1804	2078	}
1805	2079
1806	2080	/**
	2081	+ * Record the attempt that is about to run before it runs.
	2082	+ *
	2083	+ * A PHP fatal — the memory limit or max_execution_time — is not a
	2084	+ * Throwable, so no catch or finally around the generation runs when the
	2085	+ * process dies, and a failure recorded afterwards was never recorded at
	2086	+ * all: `attempts` stayed 0, the backoff never applied, and the next request
	2087	+ * started the same doomed rebuild again (a fatal every few minutes for as
	2088	+ * long as an admin was logged in). Claiming the attempt up front makes the
	2089	+ * backoff hold even when nothing after this line gets to run, and leaves a
	2090	+ * `started` stamp the next attempt can recognise as an interrupted one.
	2091	+ *
	2092	+ * @since 2.10.1
	2093	+ * @return void
	2094	+ */
	2095	+ private function claim_regeneration_attempt(): void {
	2096	+ $pending = get_option(self::REGENERATION_PENDING_OPTION, null);
	2097	+
	2098	+ // Nothing outstanding (e.g. a manual generation already satisfied it):
	2099	+ // there is no marker to retry from, so nothing to claim.
	2100	+ if (!is_array($pending) || empty($pending['since'])) {
	2101	+ return;
	2102	+ }
	2103	+
	2104	+ if (!empty($pending['started'])) {
	2105	+ // The previous attempt claimed itself and never reported back.
	2106	+ update_option(
	2107	+ self::REGENERATION_ERROR_OPTION,
	2108	+ [
	2109	+ 'message' => __('The previous automatic sitemap rebuild stopped before it finished, most likely because PHP ran out of memory or time. It is retried with a growing delay. If this keeps happening, raise the PHP memory_limit or max_execution_time, or run WP-Cron from a system cron.', 'thinkrank'),
	2110	+ 'source' => isset($pending['source']) ? (string) $pending['source'] : 'content',
	2111	+ 'attempts' => !empty($pending['attempts']) ? (int) $pending['attempts'] : 1,
	2112	+ 'time' => (int) $pending['started'],
	2113	+ ],
	2114	+ false
	2115	+ );
	2116	+ }
	2117	+
	2118	+ $attempts = (!empty($pending['attempts']) ? (int) $pending['attempts'] : 0) + 1;
	2119	+
	2120	+ $pending['attempts'] = $attempts;
	2121	+ $pending['next_attempt'] = time() + $this->regeneration_backoff($attempts);
	2122	+ $pending['started'] = time();
	2123	+
	2124	+ update_option(self::REGENERATION_PENDING_OPTION, $pending, true);
	2125	+ }
	2126	+
	2127	+ /**
	2128	+ * Delay before the next takeover after the given number of attempts.
	2129	+ *
	2130	+ * @since 2.10.1
	2131	+ * @param int $attempts Attempts made so far (1 or more).
	2132	+ * @return int Seconds.
	2133	+ */
	2134	+ private function regeneration_backoff(int $attempts): int {
	2135	+ return (int) min(
	2136	+ self::REGENERATION_TAKEOVER_GRACE * (2 ** min(max($attempts, 1), 10)),
	2137	+ self::REGENERATION_MAX_BACKOFF
	2138	+ );
	2139	+ }
	2140	+
	2141	+ /**
1807	2142	* Record a failed regeneration instead of discarding it.
1808	2143	*
1809	2144	* Keeps the pending marker in place so the rebuild is retried, but backs the
1810	2145	* next attempt off exponentially (capped) so a persistently failing
		@@ -1810,22 +2145,30 @@
1810	2145	* next attempt off exponentially (capped) so a persistently failing
1811	2146	* generation cannot run on every admin request.
1812	2147	*
1813	2148	* @since 2.2.1
1814		- * @param string $message Failure detail.
1815		- * @param string $source Either 'content' or 'settings'.
	2149	+ * @since 2.10.1 Accepts the memory limit a rebuild had to stop short of, and
	2150	+ * does not count an attempt claim_regeneration_attempt()
	2151	+ * already counted.
	2152	+ * @param string $message Failure detail.
	2153	+ * @param string $source Either 'content' or 'settings'.
	2154	+ * @param int|null $memory_limit Memory limit (bytes) the rebuild stopped
	2155	+ * short of, when that was the failure.
1816	2156	* @return void
1817	2157	*/
1818		- private function record_regeneration_failure(string $message, string $source): void {
	2158	+ private function record_regeneration_failure(string $message, string $source, ?int $memory_limit = null): void {
1819	2159	$pending = get_option(self::REGENERATION_PENDING_OPTION, []);
1820	2160	$pending = is_array($pending) ? $pending : [];
1821		- $attempts = (!empty($pending['attempts']) ? (int) $pending['attempts'] : 0) + 1;
	2161	+ $attempts = !empty($pending['attempts']) ? (int) $pending['attempts'] : 0;
1822	2162
1823		- $backoff = min(
1824		- self::REGENERATION_TAKEOVER_GRACE * (2 ** min($attempts, 10)),
1825		- self::REGENERATION_MAX_BACKOFF
1826		- );
	2163	+ // An attempt that claimed itself up front has already been counted.
	2164	+ if (empty($pending['started'])) {
	2165	+ $attempts++;
	2166	+ }
	2167	+ $attempts = max($attempts, 1);
1827	2168
	2169	+ $backoff = $this->regeneration_backoff($attempts);
	2170	+
1828	2171	// Same precedence mark_regeneration_pending() enforces: a settings
1829	2172	// rebuild outranks a content one and must not be downgraded by a failed
1830	2173	// attempt. Overwriting it routed the retry back through the content
1831	2174	// path, where should_auto_generate() can be false and the completion
		@@ -1834,20 +2177,24 @@
1834	2177	// whichever attempt actually failed.
1835	2178	$current = isset($pending['source']) ? (string) $pending['source'] : '';
1836	2179	$pending_source = ($current === 'settings' || $source === 'settings') ? 'settings' : 'content';
1837	2180
1838		- update_option(
1839		- self::REGENERATION_PENDING_OPTION,
1840		- [
1841		- 'since' => !empty($pending['since']) ? (int) $pending['since'] : time(),
1842		- 'source' => $pending_source,
1843		- 'attempts' => $attempts,
1844		- 'next_attempt' => time() + $backoff,
1845		- 'revision' => !empty($pending['revision']) ? (int) $pending['revision'] : 0,
1846		- ],
1847		- true
1848		- );
	2181	+ $marker = [
	2182	+ 'since' => !empty($pending['since']) ? (int) $pending['since'] : time(),
	2183	+ 'source' => $pending_source,
	2184	+ 'attempts' => $attempts,
	2185	+ 'next_attempt' => time() + $backoff,
	2186	+ 'revision' => !empty($pending['revision']) ? (int) $pending['revision'] : 0,
	2187	+ ];
1849	2188
	2189	+ // Remembered so has_memory_for_retry() can keep requests with no more
	2190	+ // memory than this from repeating the same attempt.
	2191	+ if ($memory_limit !== null && $memory_limit > 0) {
	2192	+ $marker['memory_limit'] = $memory_limit;
	2193	+ }
	2194	+
	2195	+ update_option(self::REGENERATION_PENDING_OPTION, $marker, true);
	2196	+
1850	2197	update_option(
1851	2198	self::REGENERATION_ERROR_OPTION,
1852	2199	[
1853	2200	'message' => $message,
		@@ -1902,16 +2249,34 @@
1902	2249	if (!self::has_overdue_regeneration()) {
1903	2250	return;
1904	2251	}
1905	2252
1906		- // Cron is running: it is about to do exactly this work.
	2253	+ $pending = get_option(self::REGENERATION_PENDING_OPTION, []);
	2254	+ $pending = is_array($pending) ? $pending : [];
	2255	+ $source = isset($pending['source']) ? (string) $pending['source'] : 'content';
	2256	+
	2257	+ // Cron is running and its own event for this rebuild is still queued
	2258	+ // and due: it is about to do exactly this work. Only then — an event
	2259	+ // that has already been consumed (e.g. it fired while another process
	2260	+ // held the generation lock) is never re-queued, and returning here
	2261	+ // unconditionally left the rebuild to requests that could not finish it.
1907	2262	if (wp_doing_cron()) {
	2263	+ $hook = $source === 'settings' ? 'thinkrank_regenerate_sitemap_settings' : 'thinkrank_regenerate_sitemap';
	2264	+ $next = wp_next_scheduled($hook);
	2265	+
	2266	+ if ($next !== false && $next <= time()) {
	2267	+ return;
	2268	+ }
	2269	+ }
	2270	+
	2271	+ // The last attempt had to stop short of this process's memory limit.
	2272	+ // Retrying at the same (or a lower) limit only repeats that, so leave
	2273	+ // the rebuild to a process with more room — WP-CLI, a system cron, or a
	2274	+ // host with a higher limit — instead of burning it on every request.
	2275	+ if (!$this->has_memory_for_retry($pending)) {
1908	2276	return;
1909	2277	}
1910	2278
1911		- $pending = get_option(self::REGENERATION_PENDING_OPTION, []);
1912		- $source = (is_array($pending) && isset($pending['source'])) ? (string) $pending['source'] : 'content';
1913		-
1914	2279	if ($source === 'settings') {
1915	2280	$this->regenerate_sitemap_from_settings();
1916	2281	return;
1917	2282	}
		@@ -1945,8 +2310,228 @@
1945	2310	delete_transient(self::GENERATION_LOCK_TRANSIENT);
1946	2311	}
1947	2312
1948	2313	/**
	2314	+ * This process's PHP memory limit in bytes.
	2315	+ *
	2316	+ * @since 2.10.1
	2317	+ * @return int Bytes, or -1 when unlimited (or unreadable).
	2318	+ */
	2319	+ private function current_memory_limit(): int {
	2320	+ $limit = (string) ini_get('memory_limit');
	2321	+
	2322	+ if ($limit === '' || $limit === '-1') {
	2323	+ return -1;
	2324	+ }
	2325	+
	2326	+ $bytes = (int) wp_convert_hr_to_bytes($limit);
	2327	+
	2328	+ return $bytes > 0 ? $bytes : -1;
	2329	+ }
	2330	+
	2331	+ /**
	2332	+ * May this process retry a rebuild that last stopped at the memory limit?
	2333	+ *
	2334	+ * Raises the limit the way wp-admin does first, so a request that can get
	2335	+ * more room than the failed attempt had is still allowed to try.
	2336	+ *
	2337	+ * @since 2.10.1
	2338	+ * @param array $pending The pending marker.
	2339	+ * @return bool True when there is no recorded memory failure, or this
	2340	+ * process has more memory than the attempt that failed.
	2341	+ */
	2342	+ private function has_memory_for_retry(array $pending): bool {
	2343	+ if (empty($pending['memory_limit'])) {
	2344	+ return true;
	2345	+ }
	2346	+
	2347	+ wp_raise_memory_limit('admin');
	2348	+
	2349	+ $limit = $this->current_memory_limit();
	2350	+
	2351	+ return $limit === -1 || $limit > (int) $pending['memory_limit'];
	2352	+ }
	2353	+
	2354	+ /**
	2355	+ * Release what one walked chunk left behind.
	2356	+ *
	2357	+ * Hydrating a chunk through get_posts()/get_terms() also stores every
	2358	+ * object and its meta in the in-process object cache, which nothing
	2359	+ * empties until the request ends. Unsetting the chunk therefore freed
	2360	+ * nothing, and the walk grew with the size of the site instead of the size
	2361	+ * of a chunk — about 1.3 GB on a 45k-post site.
	2362	+ *
	2363	+ * A persistent object cache that supports it drops only its in-process
	2364	+ * copy (`flush_runtime`); the shared store keeps its data. WordPress's
	2365	+ * default cache has no shared store, and flushing it would empty every
	2366	+ * group for the rest of the request (options, the queried object, other
	2367	+ * plugins' data), so there only the chunk's own entries are deleted. A
	2368	+ * persistent cache without `flush_runtime` is left alone: deleting from it
	2369	+ * would evict the objects for every other request too.
	2370	+ *
	2371	+ * @since 2.10.1
	2372	+ * @param int $chunk_start memory_get_usage(true) before the chunk was hydrated.
	2373	+ * @param array $groups Cache groups keyed by the chunk's object IDs.
	2374	+ * @param int[] $ids The chunk's object IDs, plus any objects it
	2375	+ * hydrated under their own (featured images).
	2376	+ * @return void
	2377	+ * @throws \Error See assert_memory_headroom().
	2378	+ */
	2379	+ private function release_walk_memory(int $chunk_start, array $groups, array $ids): void {
	2380	+ // What one chunk costs before it is released: the margin the next one
	2381	+ // needs. Measured in the same real allocated size assert_memory_headroom()
	2382	+ // compares against the limit, so the two are the same unit.
	2383	+ $this->walk_chunk_cost = max($this->walk_chunk_cost, memory_get_usage(true) - $chunk_start);
	2384	+
	2385	+ if (wp_using_ext_object_cache()) {
	2386	+ if (
	2387	+ function_exists('wp_cache_supports')
	2388	+ && wp_cache_supports('flush_runtime')
	2389	+ && function_exists('wp_cache_flush_runtime')
	2390	+ ) {
	2391	+ wp_cache_flush_runtime();
	2392	+ }
	2393	+ } elseif (!empty($ids)) {
	2394	+ foreach ($groups as $group) {
	2395	+ wp_cache_delete_multiple($ids, $group);
	2396	+ }
	2397	+ }
	2398	+
	2399	+ $this->assert_memory_headroom();
	2400	+ }
	2401	+
	2402	+ /**
	2403	+ * Cache groups get_posts() fills per post for the given post types.
	2404	+ *
	2405	+ * The post, its meta, and one relationships group per taxonomy the post
	2406	+ * type uses (update_object_term_cache()). Term objects themselves are
	2407	+ * bounded by the number of terms, not posts, so they are left cached.
	2408	+ *
	2409	+ * @since 2.10.1
	2410	+ * @param string[] $post_types Post types being walked.
	2411	+ * @return string[] Cache groups keyed by post ID.
	2412	+ */
	2413	+ private function chunk_post_cache_groups(array $post_types): array {
	2414	+ $groups = ['posts', 'post_meta'];
	2415	+
	2416	+ foreach (get_object_taxonomies($post_types) as $taxonomy) {
	2417	+ $groups[] = $taxonomy . '_relationships';
	2418	+ }
	2419	+
	2420	+ return array_values(array_unique($groups));
	2421	+ }
	2422	+
	2423	+ /**
	2424	+ * Stop an automatic rebuild before the memory limit rather than at it.
	2425	+ *
	2426	+ * A PHP memory fatal skips every catch and finally, so the lock, the
	2427	+ * failure record and the backoff are all lost with it, while stopping here
	2428	+ * is an ordinary, fully recorded failure. Checked before each chunk is
	2429	+ * hydrated, against a margin of at least the largest chunk seen so far.
	2430	+ *
	2431	+ * It throws an \Error, not an \Exception, on purpose: the per-segment
	2432	+ * catch (\Exception) blocks in generate_multiple_sitemaps() would otherwise
	2433	+ * swallow it and carry on — writing an index without the aborted segments
	2434	+ * and then pruning their files as orphans. Only the automatic rebuild's
	2435	+ * catch (\Throwable) is meant to see it.
	2436	+ *
	2437	+ * @since 2.10.1
	2438	+ * @return void
	2439	+ * @throws \Error When the automatic rebuild is close to the memory limit.
	2440	+ */
	2441	+ private function assert_memory_headroom(): void {
	2442	+ if (!$this->memory_guard) {
	2443	+ return;
	2444	+ }
	2445	+
	2446	+ $limit = $this->current_memory_limit();
	2447	+ if ($limit === -1) {
	2448	+ return;
	2449	+ }
	2450	+
	2451	+ // A fifth of the limit (at least 32 MB) for writing the files, or one
	2452	+ // and a half of the costliest chunk if that is more — and never more
	2453	+ // than half the limit either way. Without that outer cap a single
	2454	+ // anomalously expensive chunk (500 posts of serialised page-builder or
	2455	+ // ACF meta reaches hundreds of megabytes) puts the margin above the
	2456	+ // limit itself, so every later check aborts at any usage at all, the
	2457	+ // failure records this process's limit, and has_memory_for_retry()
	2458	+ // then refuses every process that has the same limit. A site that
	2459	+ // never actually ran out of memory would stop rebuilding until WP-CLI
	2460	+ // or a system cron happened to run.
	2461	+ $headroom = (int) min(
	2462	+ max(
	2463	+ min(max($limit * 0.2, 32 * MB_IN_BYTES), $limit * 0.5),
	2464	+ $this->walk_chunk_cost * 1.5
	2465	+ ),
	2466	+ $limit * 0.5
	2467	+ );
	2468	+
	2469	+ // The real allocated size, which is what PHP enforces memory_limit
	2470	+ // against; memory_get_usage(false) reports only what is handed out of
	2471	+ // those allocations and so understates the margin by the allocator's
	2472	+ // slack.
	2473	+ $usage = memory_get_usage(true);
	2474	+
	2475	+ if ($usage > $limit - $headroom) {
	2476	+ throw new \Error(
	2477	+ sprintf(
	2478	+ /* translators: 1: memory in use, 2: PHP memory limit. */
	2479	+ esc_html__('The sitemap rebuild was stopped at %1$s of the %2$s PHP memory limit, before PHP would have run out of memory. It will be retried by a process with more memory (WP-CLI or a system cron). To let it finish in the admin, raise the PHP memory_limit.', 'thinkrank'),
	2480	+ esc_html((string) size_format($usage)),
	2481	+ esc_html((string) size_format($limit))
	2482	+ ),
	2483	+ // phpcs:ignore WordPress.Security.EscapeOutput.ExceptionNotEscaped -- an integer class constant, not output.
	2484	+ self::MEMORY_ABORT_CODE
	2485	+ );
	2486	+ }
	2487	+ }
	2488	+
	2489	+ /**
	2490	+ * Run an automatic rebuild's generation with the fatal-safe bookkeeping.
	2491	+ *
	2492	+ * @since 2.10.1
	2493	+ * @param array $settings Sitemap settings.
	2494	+ * @return bool Whatever generate_and_save() returned.
	2495	+ * @throws \Throwable Whatever generation throws, after the memory guard is
	2496	+ * switched back off.
	2497	+ */
	2498	+ private function generate_for_regeneration(array $settings): bool {
	2499	+ // Same headroom wp-admin gives itself; a no-op when the limit is
	2500	+ // already higher or unlimited.
	2501	+ wp_raise_memory_limit('admin');
	2502	+
	2503	+ $this->claim_regeneration_attempt();
	2504	+ $this->memory_guard = true;
	2505	+ $this->walk_chunk_cost = 0;
	2506	+
	2507	+ try {
	2508	+ return $this->generate_and_save($settings);
	2509	+ } finally {
	2510	+ $this->memory_guard = false;
	2511	+ }
	2512	+ }
	2513	+
	2514	+ /**
	2515	+ * Record a failure thrown by an automatic rebuild.
	2516	+ *
	2517	+ * @since 2.10.1
	2518	+ * @param \Throwable $e What was thrown.
	2519	+ * @param string $source Either 'content' or 'settings'.
	2520	+ * @return void
	2521	+ */
	2522	+ private function record_thrown_regeneration_failure(\Throwable $e, string $source): void {
	2523	+ $memory_limit = null;
	2524	+
	2525	+ if ($e instanceof \Error && $e->getCode() === self::MEMORY_ABORT_CODE) {
	2526	+ $memory_limit = $this->current_memory_limit();
	2527	+ $memory_limit = $memory_limit > 0 ? $memory_limit : null;
	2528	+ }
	2529	+
	2530	+ $this->record_regeneration_failure($e->getMessage(), $source, $memory_limit);
	2531	+ }
	2532	+
	2533	+ /**
1949	2534	* Report how automatic regeneration is faring, for the admin UI.
1950	2535	*
1951	2536	* The feature used to fail invisibly: `last_generated` simply stopped
1952	2537	* advancing and nothing drew attention to it (#629).
		@@ -2044,16 +2629,20 @@
2044	2629	* auto_generate setting: the user deliberately changed inclusion rules and
2045	2630	* expects the served file to reflect them even if content-triggered
2046	2631	* auto-generation is turned off. Still respects the master `enabled` flag.
2047	2632	*
2048		- * @return void
	2633	+ * @since 2.10.0 Reports whether the served sitemap was actually rebuilt, so
	2634	+ * a caller can say so rather than assume it (#764). Existing
	2635	+ * callers that ignore the return are unaffected.
	2636	+ *
	2637	+ * @return bool True when the served sitemap now reflects the settings.
2049	2638	*/
2050		- public function regenerate_sitemap_from_settings(): void {
	2639	+ public function regenerate_sitemap_from_settings(): bool {
2051	2640	if (!$this->acquire_generation_lock()) {
2052	2641	// A manual generation (or another request's takeover) is already
2053	2642	// writing the files; the pending marker survives so this rebuild is
2054	2643	// retried rather than lost.
2055		- return;
	2644	+ return false;
2056	2645	}
2057	2646
2058	2647	try {
2059	2648	$settings = $this->get_settings('site');
		@@ -2060,25 +2649,56 @@
2060	2649	if (empty($settings['enabled'])) {
2061	2650	// The sitemap was disabled: remove the previously generated static
2062	2651	// files so the web server stops serving a stale sitemap that
2063	2652	// crawlers would otherwise keep fetching.
2064		- $this->delete_published_sitemaps();
	2653	+ //
	2654	+ // A file that could not be removed is still being served, so
	2655	+ // this is not a success. Reporting one here would tell a caller
	2656	+ // the sitemap was gone while the web server kept answering with
	2657	+ // it, which is the failure this return value exists to prevent
	2658	+ // (#764).
	2659	+ $removal = $this->delete_published_sitemaps($settings);
	2660	+ $stuck = is_array($removal['failed'] ?? null) ? $removal['failed'] : [];
	2661	+
	2662	+ if (!empty($stuck)) {
	2663	+ $this->record_regeneration_failure(
	2664	+ $this->stuck_files_message($stuck, true),
	2665	+ 'settings'
	2666	+ );
	2667	+
	2668	+ return false;
	2669	+ }
	2670	+
2065	2671	$this->mark_regeneration_complete();
2066		- return;
	2672	+
	2673	+ return true;
2067	2674	}
2068	2675
2069	2676	$revision = $this->current_regeneration_revision();
2070	2677
2071		- if ($this->generate_and_save($settings)) {
	2678	+ if ('dynamic' === $this->resolve_delivery_mode($settings)) {
	2679	+ // Returns false when a static file is stuck in the web root:
	2680	+ // the server keeps serving that file in preference to WordPress,
	2681	+ // so the switch has not taken effect (#764).
	2682	+ return $this->switch_to_dynamic_delivery($settings, $revision, 'settings');
	2683	+ }
	2684	+
	2685	+ if ($this->generate_for_regeneration($settings)) {
2072	2686	$this->mark_regeneration_complete($revision);
2073		- } else {
2074		- $this->record_regeneration_failure(
2075		- __('The sitemap files could not be written to the site root.', 'thinkrank'),
2076		- 'settings'
2077		- );
	2687	+
	2688	+ return true;
2078	2689	}
	2690	+
	2691	+ $this->record_regeneration_failure(
	2692	+ $this->write_failure_message(),
	2693	+ 'settings'
	2694	+ );
	2695	+
	2696	+ return false;
2079	2697	} catch (\Throwable $e) {
2080		- $this->record_regeneration_failure($e->getMessage(), 'settings');
	2698	+ $this->record_thrown_regeneration_failure($e, 'settings');
	2699	+
	2700	+ return false;
2081	2701	} finally {
2082	2702	$this->release_generation_lock();
2083	2703	}
2084	2704	}
		@@ -2083,8 +2703,27 @@
2083	2703	}
2084	2704	}
2085	2705
2086	2706	/**
	2707	+ * When a rebuild has been outstanding since, or 0 when none is.
	2708	+ *
	2709	+ * Lets a caller report an honest "saved, but the served file has not caught
	2710	+ * up yet" instead of a bare success (#764).
	2711	+ *
	2712	+ * @since 2.10.0
	2713	+ * @return int Unix timestamp, or 0 when nothing is pending.
	2714	+ */
	2715	+ public static function regeneration_pending_since(): int {
	2716	+ $pending = get_option(self::REGENERATION_PENDING_OPTION, []);
	2717	+
	2718	+ if (!is_array($pending) || empty($pending['since'])) {
	2719	+ return 0;
	2720	+ }
	2721	+
	2722	+ return (int) $pending['since'];
	2723	+ }
	2724	+
	2725	+ /**
2087	2726	* Remove every static sitemap file ThinkRank publishes to the web root.
2088	2727	*
2089	2728	* Called when the sitemap feature is disabled, by the cleanup route, and by
2090	2729	* both removal paths, so /sitemap.xml, /sitemap_index.xml, the segmented
		@@ -2183,10 +2822,17 @@
2183	2822	return;
2184	2823	}
2185	2824
2186	2825	$revision = $this->current_regeneration_revision();
	2826	+ $settings = $this->get_settings('site');
2187	2827
2188		- if ($this->generate_and_save($this->get_settings('site'))) {
	2828	+ // See regenerate_sitemap_from_settings(): nothing to write.
	2829	+ if ('dynamic' === $this->resolve_delivery_mode($settings)) {
	2830	+ $this->switch_to_dynamic_delivery($settings, $revision, 'content');
	2831	+ return;
	2832	+ }
	2833	+
	2834	+ if ($this->generate_for_regeneration($settings)) {
2189	2835	$this->mark_regeneration_complete($revision);
2190	2836	} else {
2191	2837	// Previously this returned quietly and last_generated simply
2192	2838	// stopped advancing, leaving the site owner with no way to learn
		@@ -2191,14 +2837,14 @@
2191	2837	// Previously this returned quietly and last_generated simply
2192	2838	// stopped advancing, leaving the site owner with no way to learn
2193	2839	// the sitemap had stopped updating (#629).
2194	2840	$this->record_regeneration_failure(
2195		- __('The sitemap files could not be written to the site root.', 'thinkrank'),
	2841	+ $this->write_failure_message(),
2196	2842	'content'
2197	2843	);
2198	2844	}
2199	2845	} catch (\Throwable $e) {
2200		- $this->record_regeneration_failure($e->getMessage(), 'content');
	2846	+ $this->record_thrown_regeneration_failure($e, 'content');
2201	2847	} finally {
2202	2848	$this->release_generation_lock();
2203	2849	}
2204	2850	}
		@@ -2215,8 +2861,26 @@
2215	2861	* @param array $settings Sitemap settings.
2216	2862	* @return bool True when the sitemap files were written.
2217	2863	*/
2218	2864	public function generate_and_save(array $settings): bool {
	2865	+ // Dynamic delivery publishes no files, so writing them here would put a
	2866	+ // static copy back in the web root for the server to serve in place of
	2867	+ // the dynamic route. Guarding at each call site left gaps — the
	2868	+ // snapshot migrator's post-import regeneration had none — so the rule
	2869	+ // lives with the writing instead.
	2870	+ //
	2871	+ // `is_collecting()` is the exception that makes dynamic delivery work
	2872	+ // at all: render_document() and collect_documents() reach this same
	2873	+ // method with the writer swapped for a collector, and that is precisely
	2874	+ // the dynamic build. Only a real write is skipped.
	2875	+ if (!$this->is_collecting() && 'dynamic' === $this->resolve_delivery_mode($settings)) {
	2876	+ // Whatever prompted this call changed the sitemap's content, so the
	2877	+ // rendered copies must not outlive it.
	2878	+ $this->flush_dynamic_cache();
	2879	+
	2880	+ return true;
	2881	+ }
	2882	+
2219	2883	// Index mode is driven by the use_sitemap_index toggle (not merely by how
2220	2884	// many sitemap_urls happen to be configured). When the toggle is on but
2221	2885	// no child sitemaps are set up yet, synthesize the per-type segmented set
2222	2886	// so we emit a real <sitemapindex> with paginated children instead of a
		@@ -2243,9 +2907,13 @@
2243	2907	// names is never touched (#515).
2244	2908	$this->prune_orphaned_segments($settings, [['filename' => basename($primary)]]);
2245	2909	}
2246	2910
2247		- if ($written) {
	2911	+ // last_generated describes what is on disk. A dynamic render publishes
	2912	+ // nothing, so advancing it would report a static publication that never
	2913	+ // happened and would let primary_sitemap_file_exists() callers believe
	2914	+ // there is a file to serve.
	2915	+ if ($written && !$this->is_collecting()) {
2248	2916	$settings['last_generated'] = gmdate('c');
2249	2917	$this->save_settings('site', null, $settings);
2250	2918	}
2251	2919
		@@ -2252,8 +2920,433 @@
2252	2920	return $written;
2253	2921	}
2254	2922
2255	2923	/**
	2924	+ * Whether this instance is rendering documents rather than publishing them.
	2925	+ *
	2926	+ * @since 2.9.0
	2927	+ *
	2928	+ * @return bool
	2929	+ */
	2930	+ private function is_collecting(): bool {
	2931	+ return $this->document_sink !== null;
	2932	+ }
	2933	+
	2934	+ /**
	2935	+ * Complete a regeneration that delivers dynamically, retiring stale files.
	2936	+ *
	2937	+ * Dynamic delivery renders nothing to disk, but that is only half the job.
	2938	+ * A web server hands back an existing `/sitemap.xml` without ever loading
	2939	+ * WordPress, so any file left over from a previous static generation goes on
	2940	+ * being served forever and {@see \ThinkRank\Frontend\SEO_Manager
	2941	+ * ::maybe_serve_sitemap()} is never reached. Switching to dynamic while
	2942	+ * leaving those files in place would therefore appear to do nothing at all.
	2943	+ *
	2944	+ * Both transitions matter and they differ:
	2945	+ *
	2946	+ * - An explicit switch to `dynamic` happens on a site whose root is usually
	2947	+ * still writable, so the files can simply be removed.
	2948	+ * - An `auto` site that becomes read-only cannot remove them, because
	2949	+ * deleting an entry needs write permission on the directory that holds
	2950	+ * it. There the stale sitemap really is stuck in front of us, and the
	2951	+ * honest outcome is a recorded failure naming it rather than a rebuild
	2952	+ * reported as complete (#754 review).
	2953	+ *
	2954	+ * Ownership is tested per file by the shared helper, so another plugin's
	2955	+ * sitemap at one of our names is never deleted (#515).
	2956	+ *
	2957	+ * @since 2.9.0
	2958	+ *
	2959	+ * @param array $settings Sitemap settings.
	2960	+ * @param int $revision Revision this rebuild is completing.
	2961	+ * @param string $source 'settings' or 'content', for the failure record.
	2962	+ * @return void
	2963	+ */
	2964	+ private function switch_to_dynamic_delivery(array $settings, int $revision, string $source): bool {
	2965	+ $this->flush_dynamic_cache();
	2966	+
	2967	+ $removal = $this->delete_published_sitemaps($settings);
	2968	+ $stuck = is_array($removal['failed'] ?? null) ? $removal['failed'] : [];
	2969	+
	2970	+ if (!empty($stuck)) {
	2971	+ $this->record_regeneration_failure($this->stuck_files_message($stuck), $source);
	2972	+
	2973	+ return false;
	2974	+ }
	2975	+
	2976	+ $this->mark_regeneration_complete($revision);
	2977	+
	2978	+ return true;
	2979	+ }
	2980	+
	2981	+ /**
	2982	+ * Why a stale file left in the web root means the change has not landed.
	2983	+ *
	2984	+ * Shared by every path that removes published files, so they cannot
	2985	+ * describe the same situation differently (#764).
	2986	+ *
	2987	+ * The two situations that reach it differ in what WordPress is doing, and
	2988	+ * the message has to say which. After a switch to dynamic delivery
	2989	+ * WordPress IS serving the sitemap and the files shadow it. After the
	2990	+ * sitemap is switched off WordPress serves nothing, so the one message
	2991	+ * used to tell a site owner who had just disabled the sitemap that it was
	2992	+ * "being served from WordPress", which is the opposite of what they did.
	2993	+ *
	2994	+ * @since 2.10.0
	2995	+ * @since 2.10.0 Public, so the REST endpoint uses it rather than a copy;
	2996	+ * takes $sitemap_disabled for the disabled path.
	2997	+ *
	2998	+ * @param string[] $stuck Basenames that could not be removed.
	2999	+ * @param bool $sitemap_disabled True when the files outlived disabling
	3000	+ * the sitemap rather than a switch to
	3001	+ * dynamic delivery.
	3002	+ * @return string
	3003	+ */
	3004	+ public function stuck_files_message(array $stuck, bool $sitemap_disabled = false): string {
	3005	+ if ($sitemap_disabled) {
	3006	+ return sprintf(
	3007	+ /* translators: 1: comma-separated file names, 2: absolute path to the WordPress root. */
	3008	+ __('The sitemap is disabled, but these files are still in the site root and your web server is still serving them: %1$s. They could not be removed because %2$s is not writable. Delete them, or ask your host to make the WordPress root writable.', 'thinkrank'),
	3009	+ implode(', ', $stuck),
	3010	+ untrailingslashit(ABSPATH)
	3011	+ );
	3012	+ }
	3013	+
	3014	+ return sprintf(
	3015	+ /* translators: 1: comma-separated file names, 2: absolute path to the WordPress root. */
	3016	+ __('The sitemap is being served from WordPress, but these files are still in the site root and your web server will keep serving them instead: %1$s. They could not be removed because %2$s is not writable. Delete them, or ask your host to make the WordPress root writable.', 'thinkrank'),
	3017	+ implode(', ', $stuck),
	3018	+ untrailingslashit(ABSPATH)
	3019	+ );
	3020	+ }
	3021	+
	3022	+ /**
	3023	+ * What to tell the site owner when publishing the files failed.
	3024	+ *
	3025	+ * The old wording stated the symptom and stopped there, so the reported
	3026	+ * cause was a guess and this reached support as a plugin fault rather than
	3027	+ * a folder permission (#752, #753). When the root is demonstrably
	3028	+ * unwritable, say that, and say what to do about it.
	3029	+ *
	3030	+ * @since 2.9.0
	3031	+ *
	3032	+ * @return string
	3033	+ */
	3034	+ private function write_failure_message(): string {
	3035	+ if (!wp_is_writable(ABSPATH)) {
	3036	+ return sprintf(
	3037	+ /* translators: %s: absolute path to the WordPress root. */
	3038	+ __('The sitemap could not be written because the folder %s is not writable by PHP. Ask your host to make the WordPress root writable, or set Sitemap Delivery to Dynamic to serve the sitemap without writing files.', 'thinkrank'),
	3039	+ untrailingslashit(ABSPATH)
	3040	+ );
	3041	+ }
	3042	+
	3043	+ return __('The sitemap files could not be written to the site root.', 'thinkrank');
	3044	+ }
	3045	+
	3046	+ /**
	3047	+ * How this site delivers its sitemap.
	3048	+ *
	3049	+ * `auto` is resolved on whether the web root can be written. That is the
	3050	+ * right signal here (unlike llms.txt, where the question is whether the
	3051	+ * server applies the .htaccess charset block): a site whose root is
	3052	+ * read-only cannot publish a sitemap file at all, and before this existed
	3053	+ * the feature simply failed with "The sitemap files could not be written to
	3054	+ * the site root." and served nothing (#752).
	3055	+ *
	3056	+ * @since 2.9.0
	3057	+ *
	3058	+ * @param array|null $settings Sitemap settings (falls back to saved ones).
	3059	+ * @return string One of 'static' or 'dynamic'. Never 'auto'.
	3060	+ */
	3061	+ public function resolve_delivery_mode(?array $settings = null): string {
	3062	+ $settings = $settings ?? $this->get_settings('site');
	3063	+ $mode = (string) ($settings['delivery_mode'] ?? 'auto');
	3064	+
	3065	+ if ('static' === $mode || 'dynamic' === $mode) {
	3066	+ return $mode;
	3067	+ }
	3068	+
	3069	+ return wp_is_writable(ABSPATH) ? 'static' : 'dynamic';
	3070	+ }
	3071	+
	3072	+ /**
	3073	+ * Render one published sitemap document without touching the filesystem.
	3074	+ *
	3075	+ * Runs the ordinary build pipeline with the writer swapped for a collector,
	3076	+ * so the bytes returned here are the bytes the static path would have
	3077	+ * written. `SitemapDeliveryParityTest` asserts that equivalence rather than
	3078	+ * trusting it.
	3079	+ *
	3080	+ * The whole set is built to answer for one file, because the index can only
	3081	+ * be assembled from the children that were actually produced. The result is
	3082	+ * cached per document, so that cost is paid once per change and not once
	3083	+ * per crawler request.
	3084	+ *
	3085	+ * @since 2.9.0
	3086	+ *
	3087	+ * @param string $filename Published file name, e.g. 'sitemap.xml'.
	3088	+ * @param array|null $settings Sitemap settings (falls back to saved ones).
	3089	+ * @return string|null XML, or null when this site does not publish that name.
	3090	+ */
	3091	+ public function render_document(string $filename, ?array $settings = null): ?string {
	3092	+ $filename = basename($filename);
	3093	+ $settings = $settings ?? $this->get_settings('site');
	3094	+
	3095	+ if (empty($settings['enabled'])) {
	3096	+ return null;
	3097	+ }
	3098	+
	3099	+ $cached = get_transient($this->dynamic_cache_key($filename));
	3100	+ if (self::ABSENT_MARKER === $cached) {
	3101	+ return null;
	3102	+ }
	3103	+ if (is_string($cached) && '' !== $cached) {
	3104	+ return $cached;
	3105	+ }
	3106	+
	3107	+ // A miss builds the whole set, because the index can only be assembled
	3108	+ // from the children that were actually produced. Caching only the
	3109	+ // requested document therefore made a crawler walking the index and its
	3110	+ // children rebuild the entire site's sitemap once per file — every post
	3111	+ // and taxonomy query repeated N times on a public endpoint (#754
	3112	+ // review). The set is built once and stored in full.
	3113	+ return $this->stream_documents($settings, $filename);
	3114	+ }
	3115	+
	3116	+ /**
	3117	+ * Build every document, caching each as it is produced, keeping one.
	3118	+ *
	3119	+ * A miss has to build the whole set, because the index can only be
	3120	+ * assembled from the children that were actually produced. It does not have
	3121	+ * to *hold* the whole set: the static path never keeps more than one page
	3122	+ * in memory, writing each to disk as it goes, and buffering every
	3123	+ * document's XML to return one of them undid that on the request path,
	3124	+ * where a large site's entire sitemap corpus would sit in a single PHP
	3125	+ * process (#754 review).
	3126	+ *
	3127	+ * So the sink writes each document straight to its cache entry and lets it
	3128	+ * go, retaining only the one this request is answering. Peak retention is
	3129	+ * one document, whatever the site's size.
	3130	+ *
	3131	+ * Concurrency: the first request through takes a short lock and does the
	3132	+ * work. One that finds the lock held waits a bounded moment for the winner
	3133	+ * to publish, then builds anyway, because serving a correct sitemap late
	3134	+ * beats serving none.
	3135	+ *
	3136	+ * @since 2.9.0
	3137	+ *
	3138	+ * @param array $settings Sitemap settings.
	3139	+ * @param string $wanted Document this request is answering.
	3140	+ * @return string|null XML for $wanted, or null when the site does not publish it.
	3141	+ */
	3142	+ private function stream_documents(array $settings, string $wanted): ?string {
	3143	+ $lock = self::DYNAMIC_CACHE_PREFIX . 'lock';
	3144	+
	3145	+ if (!$this->acquire_render_lock($lock)) {
	3146	+ for ($attempt = 0; $attempt < self::RENDER_LOCK_WAIT_ATTEMPTS; $attempt++) {
	3147	+ usleep(self::RENDER_LOCK_WAIT_MICROSECONDS);
	3148	+
	3149	+ $cached = get_transient($this->dynamic_cache_key($wanted));
	3150	+ if (self::ABSENT_MARKER === $cached) {
	3151	+ return null;
	3152	+ }
	3153	+ if (is_string($cached) && '' !== $cached) {
	3154	+ return $cached;
	3155	+ }
	3156	+ }
	3157	+ }
	3158	+
	3159	+ $kept = null;
	3160	+ // Names only. Keeping the bodies here would be the very retention this
	3161	+ // method exists to avoid.
	3162	+ $produced = [];
	3163	+
	3164	+ $previous = $this->document_sink;
	3165	+ $this->document_sink = function (string $name, string $xml) use (&$kept, &$produced, $wanted): void {
	3166	+ $produced[$name] = true;
	3167	+ set_transient($this->dynamic_cache_key($name), $xml, self::DYNAMIC_CACHE_TTL);
	3168	+
	3169	+ if ($name === $wanted) {
	3170	+ $kept = $xml;
	3171	+ }
	3172	+ };
	3173	+
	3174	+ try {
	3175	+ $this->generate_and_save($settings);
	3176	+
	3177	+ // Names the configuration lists but this build did not produce get
	3178	+ // a negative entry, so asking for one again is a cache hit rather
	3179	+ // than another full rebuild.
	3180	+ $absent = $this->published_document_names($settings);
	3181	+
	3182	+ // Also the exact name this request asked for: a paginated page past
	3183	+ // the end of a stem is a legitimate request shape that the base
	3184	+ // list cannot enumerate, and without an entry it would rebuild on
	3185	+ // every hit.
	3186	+ $absent[] = $wanted;
	3187	+
	3188	+ foreach (array_unique($absent) as $name) {
	3189	+ if (!isset($produced[$name])) {
	3190	+ set_transient($this->dynamic_cache_key($name), self::ABSENT_MARKER, self::DYNAMIC_CACHE_TTL);
	3191	+ }
	3192	+ }
	3193	+ } finally {
	3194	+ $this->document_sink = $previous;
	3195	+ delete_transient($lock);
	3196	+ }
	3197	+
	3198	+ return $kept;
	3199	+ }
	3200	+
	3201	+ /**
	3202	+ * Take the render lock, if it is free.
	3203	+ *
	3204	+ * Not atomic across processes, and deliberately so: the fallback for losing
	3205	+ * a race is duplicated work, never a wrong or missing sitemap, so a
	3206	+ * heavier primitive would buy nothing here.
	3207	+ *
	3208	+ * @since 2.9.0
	3209	+ *
	3210	+ * @param string $lock Lock transient name.
	3211	+ * @return bool True when this request holds the lock.
	3212	+ */
	3213	+ private function acquire_render_lock(string $lock): bool {
	3214	+ if (false !== get_transient($lock)) {
	3215	+ return false;
	3216	+ }
	3217	+
	3218	+ set_transient($lock, time(), self::RENDER_LOCK_TTL);
	3219	+
	3220	+ return true;
	3221	+ }
	3222	+
	3223	+ /**
	3224	+ * Build every document this site publishes and return them all.
	3225	+ *
	3226	+ * Verification and tooling only. This retains the whole set in memory, so
	3227	+ * it must never be used to answer a request: {@see self::stream_documents()}
	3228	+ * is the serving path and keeps one document at a time regardless of site
	3229	+ * size (#754 review). `SitemapDeliveryParityTest` enforces that separation
	3230	+ * by failing if the request path routes back through here.
	3231	+ *
	3232	+ * @since 2.9.0
	3233	+ *
	3234	+ * @param array $settings Sitemap settings.
	3235	+ * @return array<string,string> Filename => XML.
	3236	+ */
	3237	+ public function collect_documents(array $settings): array {
	3238	+ $documents = [];
	3239	+
	3240	+ $previous = $this->document_sink;
	3241	+ $this->document_sink = static function (string $name, string $xml) use (&$documents): void {
	3242	+ $documents[$name] = $xml;
	3243	+ };
	3244	+
	3245	+ try {
	3246	+ $this->generate_and_save($settings);
	3247	+ } finally {
	3248	+ $this->document_sink = $previous;
	3249	+ }
	3250	+
	3251	+ return $documents;
	3252	+ }
	3253	+
	3254	+ /**
	3255	+ * The file names this site publishes, without building their contents.
	3256	+ *
	3257	+ * Used by the request router to decide whether a URL is ours before doing
	3258	+ * any work. Cheap: it reads the configured child list rather than querying
	3259	+ * for entries.
	3260	+ *
	3261	+ * @since 2.9.0
	3262	+ *
	3263	+ * @param array|null $settings Sitemap settings (falls back to saved ones).
	3264	+ * @return string[] File names, including paginated pages that may exist.
	3265	+ */
	3266	+ public function published_document_names(?array $settings = null): array {
	3267	+ $settings = $settings ?? $this->get_settings('site');
	3268	+ $resolved = $this->maybe_promote_to_index($settings);
	3269	+
	3270	+ $names = [$this->get_primary_sitemap_filename($settings), 'local-sitemap.xml'];
	3271	+
	3272	+ foreach ((array) ($resolved['sitemap_urls'] ?? []) as $child) {
	3273	+ if (!is_array($child) || empty($child['enabled'])) {
	3274	+ continue;
	3275	+ }
	3276	+
	3277	+ $path = (string) wp_parse_url((string) ($child['url'] ?? ''), PHP_URL_PATH);
	3278	+ if ('' !== $path) {
	3279	+ $names[] = basename($path);
	3280	+ }
	3281	+ }
	3282	+
	3283	+ return array_values(array_unique(array_filter($names)));
	3284	+ }
	3285	+
	3286	+ /**
	3287	+ * Does this site publish a document under that name?
	3288	+ *
	3289	+ * Not a plain membership test against {@see self::published_document_names()}:
	3290	+ * that lists the configured children, and a child over the per-file URL cap
	3291	+ * is split into `<stem>-2.xml`, `<stem>-3.xml` and so on, with every page
	3292	+ * listed in the index. Gating the request router on the base list alone
	3293	+ * therefore 404'd exactly the pages the index points at, which is worse than
	3294	+ * not serving them at all.
	3295	+ *
	3296	+ * Page counts are not knowable without building, so the stem is what is
	3297	+ * matched; a page that does not exist is answered by the build finding
	3298	+ * nothing for it, and is then cached as absent.
	3299	+ *
	3300	+ * @since 2.9.0
	3301	+ *
	3302	+ * @param string $name Requested file name.
	3303	+ * @param array|null $settings Sitemap settings (falls back to saved ones).
	3304	+ * @return bool
	3305	+ */
	3306	+ public function publishes_document_name(string $name, ?array $settings = null): bool {
	3307	+ $names = $this->published_document_names($settings);
	3308	+
	3309	+ if (in_array($name, $names, true)) {
	3310	+ return true;
	3311	+ }
	3312	+
	3313	+ if (!preg_match('/^(.*)-\d+\.xml$/i', $name, $m)) {
	3314	+ return false;
	3315	+ }
	3316	+
	3317	+ return in_array($m[1] . '.xml', $names, true);
	3318	+ }
	3319	+
	3320	+ /**
	3321	+ * Transient key for a rendered document.
	3322	+ *
	3323	+ * @since 2.9.0
	3324	+ *
	3325	+ * @param string $filename Published file name.
	3326	+ * @return string
	3327	+ */
	3328	+ private function dynamic_cache_key(string $filename): string {
	3329	+ return self::DYNAMIC_CACHE_PREFIX . md5($filename);
	3330	+ }
	3331	+
	3332	+ /**
	3333	+ * Drop every cached dynamic document.
	3334	+ *
	3335	+ * Called from the same places that mark the static files stale, so the two
	3336	+ * delivery modes invalidate on identical triggers.
	3337	+ *
	3338	+ * @since 2.9.0
	3339	+ *
	3340	+ * @return void
	3341	+ */
	3342	+ public function flush_dynamic_cache(): void {
	3343	+ foreach ($this->published_document_names() as $name) {
	3344	+ delete_transient($this->dynamic_cache_key($name));
	3345	+ }
	3346	+ }
	3347	+
	3348	+ /**
2256	3349	* Resolve index-vs-single mode, synthesizing child sitemaps when needed.
2257	3350	*
2258	3351	* - When use_sitemap_index is on but no child sitemaps are configured, build
2259	3352	* the per-type segmented set so a real <sitemapindex> is produced (#127).
		@@ -2448,8 +3541,18 @@
2448	3541	// File validation failed - error details available in exception
2449	3542	return false;
2450	3543	}
2451	3544
	3545	+ // Dynamic delivery: hand the document to the collector instead of the
	3546	+ // filesystem. Reported as published, because for this run it is — the
	3547	+ // caller's success/failure bookkeeping and the index assembly both key
	3548	+ // off this return value.
	3549	+ if ($this->document_sink !== null) {
	3550	+ ($this->document_sink)($filename, $sitemap_xml);
	3551	+
	3552	+ return true;
	3553	+ }
	3554	+
2452	3555	$sitemap_path = ABSPATH . $filename;
2453	3556
2454	3557	// Use WordPress filesystem API for better security
2455	3558	global $wp_filesystem;
		@@ -2779,12 +3882,30 @@
2779	3882	$buffer = [];
2780	3883	}
2781	3884	}
2782	3885
2783		- // Flush the trailing partial page, or a single empty page when the
2784		- // type had no entries at all (parity with the previous behavior of
2785		- // always writing at least one page per configured child).
2786		- if (!empty($buffer) || $page === 0) {
	3886	+ // Flush the trailing partial page.
	3887	+ //
	3888	+ // A type that produced nothing writes no page at all in index
	3889	+ // mode (#836). It used to write one empty urlset and list it in
	3890	+ // the index, so a crawler was asked to fetch a file that
	3891	+ // answers with no URLs — Search Console reports an empty
	3892	+ // sitemap referenced from an index as a warning, and the fetch
	3893	+ // is wasted on every pass. On this site three of eleven
	3894	+ // children were empty: a post type with nothing published and
	3895	+ // two taxonomies with no terms.
	3896	+ //
	3897	+ // Single-file mode still writes its one page even when empty,
	3898	+ // because that file IS the site's /sitemap.xml and a 404 there
	3899	+ // is worse than an empty urlset. Nothing lists it, so it costs
	3900	+ // no crawl budget.
	3901	+ //
	3902	+ // Skipping the write also keeps the filename out of
	3903	+ // $results['sitemaps_generated'], which is what
	3904	+ // prune_orphaned_segments() treats as "written this run" — so
	3905	+ // a type that empties after previously publishing has its
	3906	+ // stale file deleted rather than left serving.
	3907	+ if (!empty($buffer) || ($page === 0 && $index_config === null)) {
2787	3908	$page++;
2788	3909	$this->write_sitemap_page($this->paginate_url($sitemap_config['url'], $page), $this->wrap_urlset($buffer, $settings, $image_ns), $type, count($buffer), $results, $index_children);
2789	3910	}
2790	3911
		@@ -2863,8 +3984,15 @@
2863	3984	* @param array $generated Entries from $results['sitemaps_generated'].
2864	3985	* @return string[] Basenames removed.
2865	3986	*/
2866	3987	private function prune_orphaned_segments(array $settings, array $generated): array {
	3988	+ // Rendering for a request, not publishing: there is nothing on disk
	3989	+ // this run owns, and a dynamic render must never delete the files a
	3990	+ // site's previous static mode left behind.
	3991	+ if ($this->is_collecting()) {
	3992	+ return [];
	3993	+ }
	3994	+
2867	3995	$kept = [];
2868	3996	foreach ($generated as $entry) {
2869	3997	if (!empty($entry['filename'])) {
2870	3998	$kept[strtolower((string) $entry['filename'])] = true;
		@@ -2966,9 +4094,9 @@
2966	4094	// publishes under too (this method mirrors it deliberately), so on
2967	4095	// a migrated site the file at that path may never have been ours
2968	4096	// to delete (#515).
2969	4097	$path = ABSPATH . 'local-sitemap.xml';
2970		- if (file_exists($path) && $this->webroot_sitemap_is_ours($path, $settings)) {
	4098	+ if (!$this->is_collecting() && file_exists($path) && $this->webroot_sitemap_is_ours($path, $settings)) {
2971	4099	wp_delete_file($path);
2972	4100	}
2973	4101	return false;
2974	4102	}
		@@ -2990,8 +4118,25 @@
2990	4118	*
2991	4119	* @since 1.15.x
2992	4120	* @return array Zero or one URL entry
2993	4121	*/
	4122	+ /**
	4123	+ * Does this site publish a local business sitemap right now?
	4124	+ *
	4125	+ * The same gate {@see self::regenerate_local_sitemap()} applies, asked
	4126	+ * without writing anything. Callers that need to know whether the document
	4127	+ * exists must not test the filesystem: under dynamic delivery it is served
	4128	+ * from PHP and there is no file, which is how `local-sitemap.xml` came to be
	4129	+ * dropped from robots.txt on exactly those sites (#752).
	4130	+ *
	4131	+ * @since 2.9.0
	4132	+ *
	4133	+ * @return bool True when the local sitemap has content to publish.
	4134	+ */
	4135	+ public function publishes_local_sitemap(): bool {
	4136	+ return !empty($this->collect_local_entries());
	4137	+ }
	4138	+
2994	4139	private function collect_local_entries(): array {
2995	4140	if (!class_exists('ThinkRank\\SEO\\Site_Identity_Manager')) {
2996	4141	require_once THINKRANK_PLUGIN_DIR . 'includes/seo/class-site-identity-manager.php';
2997	4142	}
		@@ -3152,8 +4297,13 @@
3152	4297	* @param array $settings Sitemap settings, for the ownership test.
3153	4298	* @return void
3154	4299	*/
3155	4300	private function cleanup_stale_pages(string $base_url, int $current_pages, array $settings): void {
	4301	+ // See prune_orphaned_segments(): a dynamic render deletes nothing.
	4302	+ if ($this->is_collecting()) {
	4303	+ return;
	4304	+ }
	4305	+
3156	4306	$filename = basename(wp_parse_url($base_url, PHP_URL_PATH));
3157	4307	if (!preg_match('/^(.*)\.xml$/i', $filename, $m)) {
3158	4308	return;
3159	4309	}