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<?php |
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namespace ABlocks\Classes\PageCache; |
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|
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if ( ! defined( 'ABSPATH' ) ) { |
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exit; |
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} |
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|
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use ABlocks\Helper; |
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use ABlocks\Performance\StyleConsolidator; |
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|
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/** |
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* Page Cache — background maintenance. |
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* |
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* Two jobs need to happen without anyone watching: |
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* |
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* 1. Expiring cached pages once the configured TTL passes. Without this the |
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* "Expire after (hours)" setting is decorative — nothing prunes, and entries |
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* live until something invalidates them. |
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* 2. Reclaiming consolidated stylesheets. They are content-addressed and |
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* referenced by cached HTML, so they cannot be purged alongside pages; they |
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* have to age out instead, or the directory grows for the life of the site. |
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* |
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* ## On Action Scheduler |
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* |
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* Recurring maintenance uses WP-Cron. It is built in, needs no dependency, and |
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* the work is two small sweeps — Action Scheduler would buy nothing here, and |
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* requiring a second plugin to make a setting work is a bad trade for a free |
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* plugin that must run standalone. |
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* |
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* Bulk warming is different: it is a queue of potentially thousands of URLs that |
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* wants throttling, retries and progress. Action Scheduler is genuinely better |
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* at that, so it is used *when present* — it commonly already is, bundled inside |
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* WooCommerce, StoreEngine and others — and WP-Cron is used otherwise. Detection |
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* is by function, never by plugin: a bundled copy is as good as an active |
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* plugin, and Action Scheduler is designed to be loaded that way. |
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*/ |
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class Scheduler { |
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|
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const PRUNE_HOOK = 'ablocks/page_cache/prune'; |
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const WARM_HOOK = 'ablocks/page_cache/warm_url'; |
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const CRAWL_HOOK = 'ablocks/page_cache/crawl'; |
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const SKIP_OPTION = 'ablocks_crawl_skip'; |
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|
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/** |
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* Days after which an unused consolidated stylesheet is reclaimed. |
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*/ |
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const CSS_MAX_AGE_DAYS = 30; |
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|
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/** |
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* Seconds between warm requests, so warming never stampedes the site it is |
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* trying to make fast. |
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*/ |
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const WARM_SPACING = 5; |
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|
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/** |
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* URLs the background crawler queues per run. |
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*/ |
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const CRAWL_BATCH = 20; |
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|
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public static function init() { |
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add_action( self::PRUNE_HOOK, [ __CLASS__, 'run_prune' ] ); |
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add_action( self::WARM_HOOK, [ __CLASS__, 'warm_url' ], 10, 1 ); |
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add_action( self::CRAWL_HOOK, [ __CLASS__, 'run_crawl' ] ); |
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add_action( 'init', [ __CLASS__, 'ensure_events' ] ); |
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} |
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|
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/** |
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* Keep the recurring jobs registered, and drop them when unused. |
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*/ |
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public static function ensure_events() { |
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$wanted = Rules::is_enabled() || (bool) Helper::get_settings( 'perf_consolidate_css', false ); |
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$next = wp_next_scheduled( self::PRUNE_HOOK ); |
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|
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if ( $wanted && ! $next ) { |
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wp_schedule_event( time() + HOUR_IN_SECONDS, 'hourly', self::PRUNE_HOOK ); |
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} elseif ( ! $wanted && $next ) { |
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// Leave no orphan cron entry behind when both features are off. |
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wp_unschedule_event( $next, self::PRUNE_HOOK ); |
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} |
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|
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$crawl_wanted = Rules::is_enabled() && (bool) Helper::get_settings( 'perf_page_cache_crawler', false ); |
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$crawl_next = wp_next_scheduled( self::CRAWL_HOOK ); |
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|
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if ( $crawl_wanted && ! $crawl_next ) { |
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wp_schedule_event( time() + ( 5 * MINUTE_IN_SECONDS ), 'hourly', self::CRAWL_HOOK ); |
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} elseif ( ! $crawl_wanted && $crawl_next ) { |
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wp_unschedule_event( $crawl_next, self::CRAWL_HOOK ); |
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} |
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} |
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|
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/** |
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* Top up the cache with pages that are not in it yet. |
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* |
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* Deliberately incremental rather than a full crawl. It queues a small batch |
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* of *uncached* URLs each hour, so a large site fills in gradually instead of |
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* the site being hit with thousands of renders at once — and once the cache |
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* is warm the job finds nothing to do and costs almost nothing. |
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* |
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* This is also why nothing auto-crawls after a site-wide purge. Rebuilding |
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* every page the instant a header is edited is a self-inflicted load spike at |
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* exactly the wrong moment; letting the crawler refill it over the following |
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* hours, while visitors organically warm the popular pages, is gentler and |
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* reaches the same place. |
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* |
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* @return int URLs queued. |
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*/ |
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public static function run_crawl() { |
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if ( ! Rules::is_enabled() ) { |
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return 0; |
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} |
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|
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$batch = (int) apply_filters( |
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'ablocks/perf/page_cache/crawl_batch', |
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(int) Helper::get_settings( 'perf_page_cache_crawl_batch', self::CRAWL_BATCH ) |
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); |
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$batch = max( 1, min( 200, $batch ) ); |
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|
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// Pull a wider slice than the batch so that, once the head of the list is |
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// cached, the crawler can still find uncached pages further down instead |
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// of re-checking the same first N every hour. |
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$candidates = self::warmable_urls( $batch * 10 ); |
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$skip = self::skip_list(); |
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$now = time(); |
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$missing = []; |
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|
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foreach ( $candidates as $url ) { |
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if ( self::is_cached( $url ) ) { |
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// Cached now, so any earlier failures are irrelevant. |
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unset( $skip[ $url ] ); |
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continue; |
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} |
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|
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// Some URLs can never be cached — a login or account page sets a |
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// cookie, so the write path correctly refuses it. Without a memory of |
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// that, the crawler re-requests those same pages every single hour |
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// forever, which is pure waste on a job designed to run unattended. |
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if ( isset( $skip[ $url ]['until'] ) && $skip[ $url ]['until'] > $now ) { |
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continue; |
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} |
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|
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$missing[] = $url; |
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|
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if ( count( $missing ) >= $batch ) { |
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break; |
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} |
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}//end foreach |
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|
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if ( empty( $missing ) ) { |
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self::save_skip_list( $skip ); |
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return 0; |
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} |
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|
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foreach ( $missing as $url ) { |
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$attempts = isset( $skip[ $url ]['n'] ) ? (int) $skip[ $url ]['n'] + 1 : 1; |
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|
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$skip[ $url ] = [ |
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'n' => $attempts, |
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// Three attempts is enough to distinguish "not visited yet" from |
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// "will never cache"; after that, back off for a day so a page |
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// that becomes cacheable is still picked up eventually. |
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'until' => $attempts >= 3 ? $now + DAY_IN_SECONDS : 0, |
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]; |
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} |
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|
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self::save_skip_list( $skip ); |
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|
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return self::queue_warm( $missing, 0 ); |
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} |
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|
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/** |
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* Per-URL crawl attempt record. |
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* |
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* @return array<string, array{n:int, until:int}> |
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*/ |
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private static function skip_list() { |
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$list = get_option( self::SKIP_OPTION, [] ); |
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return is_array( $list ) ? $list : []; |
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} |
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|
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/** |
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* Persist the crawl attempt record, bounded. |
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* |
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* @param array $list Attempt record. |
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*/ |
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private static function save_skip_list( $list ) { |
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// Bounded so a site with a very large sitemap cannot grow this option |
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// without limit. Entries still in backoff are kept in preference to ones |
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// that have simply not been reached yet. |
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if ( count( $list ) > 500 ) { |
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uasort( |
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$list, |
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function ( $a, $b ) { |
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return ( isset( $b['until'] ) ? $b['until'] : 0 ) <=> ( isset( $a['until'] ) ? $a['until'] : 0 ); |
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} |
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); |
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$list = array_slice( $list, 0, 500, true ); |
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} |
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|
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update_option( self::SKIP_OPTION, $list, false ); |
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} |
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|
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/** |
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* Does a cache entry already exist for a URL? |
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* |
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* @param string $url URL to check. |
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* @return bool |
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*/ |
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public static function is_cached( $url ) { |
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$parts = wp_parse_url( $url ); |
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if ( empty( $parts['host'] ) ) { |
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return false; |
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} |
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|
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$file = Store::file_path( |
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$parts['host'], |
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isset( $parts['path'] ) ? $parts['path'] : '/', |
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'' |
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); |
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|
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return $file && file_exists( $file ); |
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} |
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|
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/** |
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* Remove every scheduled job. Called on deactivation. |
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*/ |
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public static function clear_events() { |
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wp_clear_scheduled_hook( self::PRUNE_HOOK ); |
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|
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if ( self::has_action_scheduler() ) { |
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as_unschedule_all_actions( self::WARM_HOOK ); |
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} |
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} |
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|
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/** |
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* Expire stale cached pages and reclaim unused stylesheets. |
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* |
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* @return array{pages:int, css:int} |
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*/ |
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public static function run_prune() { |
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$pages = Store::prune(); |
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|
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$css_days = (int) apply_filters( 'ablocks/perf/page_cache/css_max_age_days', self::CSS_MAX_AGE_DAYS ); |
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$css = StyleConsolidator::prune( $css_days ); |
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|
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return [ |
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'pages' => (int) $pages, |
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'css' => (int) $css, |
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]; |
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} |
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|
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/** |
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* Queue a set of URLs to be rendered into the cache. |
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* |
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* Requests are spaced rather than fired at once. Warming exists to spare |
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* visitors a render; doing it in one burst would hand the site the exact |
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* load spike the cache is meant to prevent. |
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* |
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* @param string[] $urls URLs to warm. |
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* @param int $delay Seconds before the first request. |
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* @return int Number of jobs queued. |
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*/ |
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public static function queue_warm( array $urls, $delay = 10 ) { |
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$urls = array_values( array_unique( array_filter( array_map( 'esc_url_raw', $urls ) ) ) ); |
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if ( empty( $urls ) ) { |
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return 0; |
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} |
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|
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$spacing = max( 1, (int) apply_filters( 'ablocks/perf/page_cache/warm_spacing', self::WARM_SPACING ) ); |
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$queued = 0; |
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|
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foreach ( $urls as $index => $url ) { |
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$when = time() + (int) $delay + ( $index * $spacing ); |
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|
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if ( self::has_action_scheduler() ) { |
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as_schedule_single_action( $when, self::WARM_HOOK, [ $url ], 'ablocks' ); |
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} else { |
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// WP-Cron dedupes on hook + args, so a URL already queued is not |
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// queued twice — which is the behaviour we want anyway. |
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if ( ! wp_next_scheduled( self::WARM_HOOK, [ $url ] ) ) { |
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wp_schedule_single_event( $when, self::WARM_HOOK, [ $url ] ); |
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} |
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} |
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|
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$queued++; |
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} |
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|
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return $queued; |
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} |
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|
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/** |
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* Render one URL so its cache entry exists before a visitor asks for it. |
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* |
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* A plain anonymous GET: the write path decides on its own whether the |
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* response is cacheable, so warming needs no special privileges and cannot |
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* cache something a visitor would not have. |
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* |
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* @param string $url URL to fetch. |
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*/ |
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public static function warm_url( $url ) { |
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$url = esc_url_raw( (string) $url ); |
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if ( empty( $url ) ) { |
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return; |
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} |
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|
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// Same-origin only. This runs from a queue whose contents could be |
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// filtered by other code, and it must never become a way to make the |
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// server issue arbitrary outbound requests. |
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$home = wp_parse_url( home_url() ); |
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$want = wp_parse_url( $url ); |
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if ( empty( $want['host'] ) || empty( $home['host'] ) || strtolower( $want['host'] ) !== strtolower( $home['host'] ) ) { |
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return; |
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} |
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|
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wp_remote_get( |
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$url, |
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[ |
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'timeout' => 15, |
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'blocking' => false, |
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'sslverify' => false, |
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'user-agent' => 'aBlocks-Cache-Warmer/' . ABLOCKS_VERSION, |
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'headers' => [ 'X-ABlocks-Warm' => '1' ], |
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] |
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); |
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} |
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|
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/** |
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* URLs worth warming. |
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* |
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* The site's own sitemap is preferred: it is the site's statement of what |
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* matters, and it includes archives, taxonomy and author pages that a post |
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* query alone would miss — which is what the other preloaders in this space |
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* read too. The post query remains as a fallback for sites that have the |
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* sitemap disabled or replaced. |
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* |
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* @param int $limit Maximum URLs to return. |
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* @return string[] |
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*/ |
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public static function warmable_urls( $limit = 100 ) { |
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$limit = max( 1, (int) $limit ); |
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|
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$urls = self::sitemap_urls( $limit ); |
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if ( count( $urls ) > 1 ) { |
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return array_slice( $urls, 0, $limit ); |
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} |
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|
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return self::queried_urls( $limit ); |
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} |
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|
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/** |
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* URLs read from the WordPress sitemap index. |
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* |
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* Fetched over HTTP rather than by calling the sitemap provider directly, |
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* because SEO plugins commonly replace core's sitemap with their own at the |
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* same address; going through the URL gets whichever one the site actually |
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* publishes. |
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* |
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* @param int $limit Stop after this many URLs. |
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* @return string[] |
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*/ |
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public static function sitemap_urls( $limit = 100 ) { |
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// Several candidates, because the address depends on what publishes the |
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// sitemap: core uses wp-sitemap.xml, Yoast and RankMath use |
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// sitemap_index.xml, others use sitemap.xml. Probing costs one request |
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// each and only until the first that answers, which beats making the |
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// user configure it. A site with none of them falls back to the query. |
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$candidates = (array) apply_filters( |
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'ablocks/perf/page_cache/sitemap_urls', |
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[ |
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home_url( '/wp-sitemap.xml' ), |
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home_url( '/sitemap_index.xml' ), |
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home_url( '/sitemap.xml' ), |
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] |
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); |
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|
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$children = []; |
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foreach ( $candidates as $candidate ) { |
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$children = self::read_sitemap( $candidate ); |
| 378 |
if ( ! empty( $children ) ) { |
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break; |
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} |
| 381 |
} |
| 382 |
|
| 383 |
if ( empty( $children ) ) { |
| 384 |
return []; |
| 385 |
} |
| 386 |
|
| 387 |
// An index lists sub-sitemaps; a flat sitemap lists pages. Both arrive as |
| 388 |
// <loc> values, so tell them apart by whether they look like sitemaps. |
| 389 |
$sub = array_values( |
| 390 |
array_filter( |
| 391 |
$children, |
| 392 |
function ( $url ) { |
| 393 |
return (bool) preg_match( '#\.xml(\?|$)#i', $url ); |
| 394 |
} |
| 395 |
) |
| 396 |
); |
| 397 |
|
| 398 |
if ( empty( $sub ) ) { |
| 399 |
return array_slice( $children, 0, $limit ); |
| 400 |
} |
| 401 |
|
| 402 |
$urls = [ home_url( '/' ) ]; |
| 403 |
foreach ( $sub as $child ) { |
| 404 |
$urls = array_merge( $urls, self::read_sitemap( $child ) ); |
| 405 |
if ( count( $urls ) >= $limit ) { |
| 406 |
break; |
| 407 |
} |
| 408 |
} |
| 409 |
|
| 410 |
return array_values( array_unique( $urls ) ); |
| 411 |
} |
| 412 |
|
| 413 |
/** |
| 414 |
* Extract <loc> values from one sitemap document. |
| 415 |
* |
| 416 |
* @param string $url Sitemap URL. |
| 417 |
* @return string[] |
| 418 |
*/ |
| 419 |
private static function read_sitemap( $url ) { |
| 420 |
if ( ! self::same_origin( $url ) ) { |
| 421 |
return []; |
| 422 |
} |
| 423 |
|
| 424 |
$response = wp_remote_get( |
| 425 |
$url, |
| 426 |
[ |
| 427 |
'timeout' => 20, |
| 428 |
'sslverify' => false, |
| 429 |
'user-agent' => 'aBlocks-Cache-Warmer/' . ABLOCKS_VERSION, |
| 430 |
] |
| 431 |
); |
| 432 |
|
| 433 |
if ( is_wp_error( $response ) || 200 !== (int) wp_remote_retrieve_response_code( $response ) ) { |
| 434 |
return []; |
| 435 |
} |
| 436 |
|
| 437 |
$body = wp_remote_retrieve_body( $response ); |
| 438 |
if ( empty( $body ) || ! preg_match_all( '#<loc>\s*([^<]+?)\s*</loc>#i', $body, $matches ) ) { |
| 439 |
return []; |
| 440 |
} |
| 441 |
|
| 442 |
$urls = []; |
| 443 |
foreach ( $matches[1] as $loc ) { |
| 444 |
$loc = esc_url_raw( html_entity_decode( trim( $loc ), ENT_QUOTES, 'UTF-8' ) ); |
| 445 |
if ( $loc && self::same_origin( $loc ) ) { |
| 446 |
$urls[] = $loc; |
| 447 |
} |
| 448 |
} |
| 449 |
|
| 450 |
return array_values( array_unique( $urls ) ); |
| 451 |
} |
| 452 |
|
| 453 |
/** |
| 454 |
* Is a URL on this site? |
| 455 |
* |
| 456 |
* @param string $url Candidate URL. |
| 457 |
* @return bool |
| 458 |
*/ |
| 459 |
private static function same_origin( $url ) { |
| 460 |
$home = wp_parse_url( home_url() ); |
| 461 |
$want = wp_parse_url( $url ); |
| 462 |
|
| 463 |
return ! empty( $want['host'] ) |
| 464 |
&& ! empty( $home['host'] ) |
| 465 |
&& strtolower( $want['host'] ) === strtolower( $home['host'] ); |
| 466 |
} |
| 467 |
|
| 468 |
/** |
| 469 |
* Fallback URL list: recently modified public posts, plus the front page. |
| 470 |
* |
| 471 |
* @param int $limit Maximum URLs to return. |
| 472 |
* @return string[] |
| 473 |
*/ |
| 474 |
private static function queried_urls( $limit = 100 ) { |
| 475 |
$limit = max( 1, (int) $limit ); |
| 476 |
|
| 477 |
$post_types = array_values( |
| 478 |
array_filter( |
| 479 |
get_post_types( [ 'public' => true ], 'names' ), |
| 480 |
function ( $type ) { |
| 481 |
return 'attachment' !== $type; |
| 482 |
} |
| 483 |
) |
| 484 |
); |
| 485 |
|
| 486 |
$query = new \WP_Query( |
| 487 |
[ |
| 488 |
'post_type' => $post_types, |
| 489 |
'post_status' => 'publish', |
| 490 |
'posts_per_page' => $limit, |
| 491 |
'orderby' => 'modified', |
| 492 |
'order' => 'DESC', |
| 493 |
'has_password' => false, |
| 494 |
'ignore_sticky_posts' => true, |
| 495 |
'no_found_rows' => true, |
| 496 |
'update_post_meta_cache' => false, |
| 497 |
'update_post_term_cache' => false, |
| 498 |
'fields' => 'ids', |
| 499 |
] |
| 500 |
); |
| 501 |
|
| 502 |
$urls = [ home_url( '/' ) ]; |
| 503 |
foreach ( $query->posts as $post_id ) { |
| 504 |
$permalink = get_permalink( $post_id ); |
| 505 |
if ( $permalink ) { |
| 506 |
$urls[] = $permalink; |
| 507 |
} |
| 508 |
} |
| 509 |
|
| 510 |
return array_values( array_unique( $urls ) ); |
| 511 |
} |
| 512 |
|
| 513 |
/** |
| 514 |
* Is Action Scheduler available to this request? |
| 515 |
* |
| 516 |
* Checked by function, not by plugin: Action Scheduler is normally bundled |
| 517 |
* inside another plugin's vendor directory rather than activated on its own, |
| 518 |
* and a bundled copy works exactly as well. |
| 519 |
* |
| 520 |
* @return bool |
| 521 |
*/ |
| 522 |
public static function has_action_scheduler() { |
| 523 |
return function_exists( 'as_schedule_single_action' ) |
| 524 |
&& function_exists( 'as_unschedule_all_actions' ); |
| 525 |
} |
| 526 |
|
| 527 |
/** |
| 528 |
* Which backend bulk warming will use, for display. |
| 529 |
* |
| 530 |
* @return string |
| 531 |
*/ |
| 532 |
public static function warm_backend() { |
| 533 |
return self::has_action_scheduler() ? 'action-scheduler' : 'wp-cron'; |
| 534 |
} |
| 535 |
} |
| 536 |
|
