| @@ -2,13 +2,19 @@ | ||
| 2 | 2 | /** |
| 3 | 3 | * Resource Hints processor — pure HTML transformer for resource hints. |
| 4 | 4 | * |
| 5 | 5 | * Given a fully-rendered page and the Preload module's options, it: |
| 6 | - * 1. Finds the first N above-the-fold <img> (the LCP candidate) and emits | |
| 7 | - * a <link rel="preload" as="image" fetchpriority="high"> for each in | |
| 8 | - * the <head>, carrying srcset/sizes as imagesrcset/imagesizes so the | |
| 6 | + * 1. Ranks every eligible <img> by the largest declared size it can read — | |
| 7 | + * width×height attributes, else the widest srcset candidate — boosted by | |
| 8 | + * the author's own priority signals (fetchpriority="high", an explicit | |
| 9 | + * loading="eager") and lightly weighted by document position, and emits | |
| 10 | + * a <link rel="preload" as="image" fetchpriority="high"> for the top N | |
| 11 | + * in the <head>, carrying srcset/sizes as imagesrcset/imagesizes so the | |
| 9 | 12 | * browser can pick the right candidate — then adds fetchpriority="high" |
| 10 | - * to the <img> itself so it beats any loading="lazy" the theme set. | |
| 13 | + * to the <img> itself. Ranking by size rather than document position: | |
| 14 | + * the first images on a real page are usually header chrome, not the | |
| 15 | + * hero (#96). Images inside <footer>/<nav>/<aside>, images the theme | |
| 16 | + * explicitly lazy-loads, and tiny images never compete (FBS-84576). | |
| 11 | 17 | * 2. Emits <link rel="preconnect"> for detected web-font hosts |
| 12 | 18 | * (fonts.googleapis.com + fonts.gstatic.com) and any user-supplied |
| 13 | 19 | * hosts, deduped. |
| 14 | 20 | * |
| @@ -57,8 +63,20 @@ | ||
| 57 | 63 | [ $html, $preload ] = self::build_lcp_preload( $html, $count, $exclusions ); |
| 58 | 64 | $hints .= $preload; |
| 59 | 65 | } |
| 60 | 66 | |
| 67 | + // The manual list runs AFTER the automatic pick so it can deduplicate | |
| 68 | + // against it: a URL both name should carry ONE hint, not two. It exists | |
| 69 | + // for the image the detector cannot see — most often a hero section's | |
| 70 | + // CSS background-image, where the LCP element is a <div> with none of | |
| 71 | + // the width/height/fetchpriority signals the scorer reads. On the site | |
| 72 | + // that surfaced this, 3.3s of a 5.3s mobile LCP was pure discovery | |
| 73 | + // delay for exactly such an image. (FBS-84578) | |
| 74 | + $manual = array_filter( array_map( 'strval', (array) ( $opts['preload_images'] ?? array() ) ) ); | |
| 75 | + if ( ! empty( $manual ) ) { | |
| 76 | + $hints .= self::build_manual_image_preloads( $manual, $hints ); | |
| 77 | + } | |
| 78 | + | |
| 61 | 79 | // Full-page eager promotion for Lazy-excluded heroes (FBS-83553 H2). The |
| 62 | 80 | // Lazy module only filters the_content/thumbnail/avatar/widget, so a |
| 63 | 81 | // theme/builder hero printed OUTSIDE those keeps WP core's |
| 64 | 82 | // loading="lazy". This pass runs over the whole document, so it can reach |
| @@ -77,8 +95,61 @@ | ||
| 77 | 95 | return self::inject_into_head( $html, $hints ); |
| 78 | 96 | } |
| 79 | 97 | |
| 80 | 98 | /** |
| 99 | + * How many entries of the manual preload list are honoured. Preloading | |
| 100 | + * competes with the page for its top network priority — a long list | |
| 101 | + * inverts the benefit, so the cap is deliberately small. | |
| 102 | + */ | |
| 103 | + private const MAX_MANUAL_PRELOADS = 3; | |
| 104 | + | |
| 105 | + /** | |
| 106 | + * One `<link rel="preload" as="image">` per manual list entry. | |
| 107 | + * | |
| 108 | + * Entries are full URLs or site-relative paths. Anything that is neither | |
| 109 | + * (a data: URI, a bare word) is skipped rather than guessed at, and a URL | |
| 110 | + * the automatic pick already emitted is skipped too — one hint per image, | |
| 111 | + * whoever names it first. | |
| 112 | + * | |
| 113 | + * @param array<int,string> $urls The configured list. | |
| 114 | + * @param string $existing_hints Hints already built this request. | |
| 115 | + */ | |
| 116 | + private static function build_manual_image_preloads( array $urls, string $existing_hints ): string { | |
| 117 | + /** | |
| 118 | + * Filter the manual image-preload list before it is emitted. | |
| 119 | + * | |
| 120 | + * @param array<int,string> $urls Configured URLs, in panel order. | |
| 121 | + */ | |
| 122 | + $urls = (array) apply_filters( 'xspeed_preload_images', $urls ); | |
| 123 | + | |
| 124 | + $out = ''; | |
| 125 | + $seen = array(); | |
| 126 | + foreach ( $urls as $url ) { | |
| 127 | + $url = trim( (string) $url ); | |
| 128 | + if ( '' === $url ) { | |
| 129 | + continue; | |
| 130 | + } | |
| 131 | + // A full URL or a site-relative path; nothing else is guessable. | |
| 132 | + $is_absolute = (bool) preg_match( '#^https?://#i', $url ); | |
| 133 | + $is_relative = '' !== $url && '/' === $url[0] && ( strlen( $url ) < 2 || '/' !== $url[1] ); | |
| 134 | + if ( ! $is_absolute && ! $is_relative ) { | |
| 135 | + continue; | |
| 136 | + } | |
| 137 | + $href = esc_url( $url ); | |
| 138 | + if ( '' === $href || isset( $seen[ $href ] ) || false !== strpos( $existing_hints, 'href="' . $href . '"' ) ) { | |
| 139 | + continue; | |
| 140 | + } | |
| 141 | + $seen[ $href ] = true; | |
| 142 | + $out .= '<link rel="preload" as="image" href="' . $href . '" fetchpriority="high">'; | |
| 143 | + if ( count( $seen ) >= self::MAX_MANUAL_PRELOADS ) { | |
| 144 | + break; | |
| 145 | + } | |
| 146 | + } | |
| 147 | + | |
| 148 | + return $out; | |
| 149 | + } | |
| 150 | + | |
| 151 | + /** | |
| 81 | 152 | * Strip core `loading="lazy"` and add `fetchpriority="high"` + |
| 82 | 153 | * `decoding="async"` on every <img> whose tag matches one of the given |
| 83 | 154 | * exclusion substrings. Mirrors what Lazy_Loader does for an excluded image |
| 84 | 155 | * inside the_content, but page-wide so heroes outside it are covered too. |
| @@ -168,9 +239,8 @@ | ||
| 168 | 239 | return array( $html, '' ); |
| 169 | 240 | } |
| 170 | 241 | |
| 171 | 242 | $preload = ''; |
| 172 | - $done = 0; | |
| 173 | 243 | |
| 174 | 244 | // Snapshot of already-present preload markup, for idempotency: a second |
| 175 | 245 | // pass (e.g. cache-off ob_start over an already-processed body) must not |
| 176 | 246 | // re-emit a <link> for an image we preloaded before. |
| @@ -175,64 +245,151 @@ | ||
| 175 | 245 | // pass (e.g. cache-off ob_start over an already-processed body) must not |
| 176 | 246 | // re-emit a <link> for an image we preloaded before. |
| 177 | 247 | $existing = $html; |
| 178 | 248 | |
| 179 | - // Walk <img> tags in document order. preg_replace_callback lets us | |
| 180 | - // rewrite the tag (add fetchpriority) and harvest the src in one pass. | |
| 181 | - $html = preg_replace_callback( | |
| 182 | - '#<img\b[^>]*>#i', | |
| 183 | - static function ( array $m ) use ( &$done, &$preload, $count, $exclusions, $existing ) { | |
| 184 | - $tag = $m[0]; | |
| 185 | - if ( $done >= $count ) { | |
| 186 | - return $tag; | |
| 187 | - } | |
| 249 | + // PASS 1 — collect every eligible <img> and score it. | |
| 250 | + // | |
| 251 | + // This used to preload the first N eligible tags in DOCUMENT ORDER. | |
| 252 | + // Position is not a proxy for rendered size: on real pages the first | |
| 253 | + // images are header chrome, breadcrumbs or badge rows, and the actual | |
| 254 | + // LCP element is a hero further down. Preloading the wrong image gains | |
| 255 | + // nothing — it just adds a high-priority request competing with the | |
| 256 | + // one that matters, and the feature reported success either way. The | |
| 257 | + // marker list and size gate were heuristics layered on top of the | |
| 258 | + // wrong primitive rather than replacing it. (#96) | |
| 259 | + $candidates = array(); | |
| 260 | + $skip_ranges = self::chrome_container_ranges( $html ); | |
| 261 | + if ( preg_match_all( '#<img\b[^>]*>#i', $html, $matches, PREG_OFFSET_CAPTURE ) ) { | |
| 262 | + foreach ( $matches[0] as $index => $match ) { | |
| 263 | + [ $tag, $offset ] = $match; | |
| 188 | 264 | |
| 189 | 265 | // Skip anything the user excluded. |
| 266 | + $excluded = false; | |
| 190 | 267 | foreach ( $exclusions as $needle ) { |
| 191 | 268 | if ( '' !== $needle && false !== stripos( $tag, $needle ) ) { |
| 192 | - return $tag; | |
| 269 | + $excluded = true; | |
| 270 | + break; | |
| 193 | 271 | } |
| 194 | 272 | } |
| 273 | + if ( $excluded ) { | |
| 274 | + continue; | |
| 275 | + } | |
| 195 | 276 | |
| 277 | + // An image inside <footer>/<nav>/<aside> is site chrome by | |
| 278 | + // construction — a footer brand strip or FAQ illustration can | |
| 279 | + // never be the LCP element, whatever size it declares. On the | |
| 280 | + // FBS-84576 repro these decoys outranked the real hero three | |
| 281 | + // times on one layout. | |
| 282 | + if ( self::offset_in_ranges( $offset, $skip_ranges ) ) { | |
| 283 | + continue; | |
| 284 | + } | |
| 285 | + | |
| 286 | + // An image the theme explicitly lazy-loads is never the | |
| 287 | + // intended LCP — the author has already said "this can wait". | |
| 288 | + // Preloading it would contradict the markup and steal | |
| 289 | + // bandwidth from the image that matters. (FBS-84576) | |
| 290 | + if ( 'lazy' === strtolower( self::attr( $tag, 'loading' ) ) ) { | |
| 291 | + continue; | |
| 292 | + } | |
| 293 | + | |
| 196 | 294 | // Resolve the EFFECTIVE image URL. Page builders + JS lazy |
| 197 | 295 | // loaders park a placeholder (a data: URI or a 1px spacer) in |
| 198 | 296 | // `src` and the real URL in `data-src`, so the hero the browser |
| 199 | - // actually paints is behind data-src. Reading `src` alone made | |
| 200 | - // the LCP picker skip the real hero and fasten onto a later plain | |
| 201 | - // <img> decoy. Prefer data-src when src is a placeholder. | |
| 202 | - // (FBS-83553 H1) | |
| 297 | + // actually paints is behind data-src. (FBS-83553 H1) | |
| 203 | 298 | [ $src, $srcset, $sizes ] = self::effective_image_src( $tag ); |
| 204 | 299 | if ( '' === $src ) { |
| 205 | - return $tag; // no real URL (pure data-URI spacer, no data-src). | |
| 300 | + continue; // no real URL (pure data-URI spacer, no data-src). | |
| 206 | 301 | } |
| 207 | 302 | |
| 208 | - // Size gate: never spend the LCP preload budget on an image that | |
| 209 | - // is obviously not the hero — a logo/icon/avatar. When explicit | |
| 210 | - // width & height are on the tag and it's small in BOTH dimensions, | |
| 211 | - // skip it and keep looking. Missing dimensions → don't guess, let | |
| 212 | - // it through. (FBS-83553 H1 "logo before hero".) | |
| 303 | + // Chrome markers / explicit opt-out / obviously-tiny images | |
| 304 | + // never compete. (FBS-83553 H1 "logo before hero".) | |
| 213 | 305 | if ( self::looks_too_small( $tag ) ) { |
| 214 | - return $tag; | |
| 306 | + continue; | |
| 215 | 307 | } |
| 216 | 308 | |
| 217 | - // Idempotency: if this src is already the target of a | |
| 218 | - // rel="preload" as="image" link, count it as done (so the | |
| 219 | - // budget is respected) but don't emit a duplicate <link>. | |
| 220 | - $already = (bool) preg_match( | |
| 221 | - '#rel=["\']preload["\'][^>]*as=["\']image["\'][^>]*' . preg_quote( $src, '#' ) . '#i', | |
| 222 | - $existing | |
| 309 | + $candidates[] = array( | |
| 310 | + 'tag' => $tag, | |
| 311 | + 'src' => $src, | |
| 312 | + 'srcset' => $srcset, | |
| 313 | + 'sizes' => $sizes, | |
| 314 | + 'score' => self::weighted_score( self::lcp_score( $tag, $srcset ), $tag, $index ), | |
| 315 | + 'order' => $index, | |
| 223 | 316 | ); |
| 224 | - if ( ! $already ) { | |
| 225 | - $preload .= self::preload_link( $src, $srcset, $sizes ); | |
| 317 | + } | |
| 318 | + } | |
| 319 | + | |
| 320 | + // PASS 1b — the same for CSS background images. | |
| 321 | + // | |
| 322 | + // On a page builder the hero is usually a background-image on the | |
| 323 | + // section, not an <img>, so an <img>-only candidate set never contained | |
| 324 | + // the element that actually paints as LCP. It preloaded whatever <img> | |
| 325 | + // happened to be there — measured at 0ms against the feature switched | |
| 326 | + // off, while spending a high-priority fetch on the critical path — or, | |
| 327 | + // on a page with no <img> at all, emitted nothing. (#247) | |
| 328 | + foreach ( self::background_candidates( $html, $exclusions, $skip_ranges ) as $bg ) { | |
| 329 | + $candidates[] = $bg; | |
| 330 | + } | |
| 331 | + | |
| 332 | + if ( empty( $candidates ) ) { | |
| 333 | + return array( $html, '' ); | |
| 334 | + } | |
| 335 | + | |
| 336 | + // Rank by score, biggest first. Document order breaks ties, so two | |
| 337 | + // equally-sized images (or two of unknown size) keep the previous | |
| 338 | + // first-wins behaviour — the change only matters when we can actually | |
| 339 | + // tell one is larger. | |
| 340 | + usort( | |
| 341 | + $candidates, | |
| 342 | + static function ( array $a, array $b ) { | |
| 343 | + if ( $a['score'] === $b['score'] ) { | |
| 344 | + return $a['order'] <=> $b['order']; | |
| 226 | 345 | } |
| 227 | - $done++; | |
| 346 | + return $b['score'] <=> $a['score']; | |
| 347 | + } | |
| 348 | + ); | |
| 228 | 349 | |
| 350 | + $winners = array_slice( $candidates, 0, $count ); | |
| 351 | + | |
| 352 | + // PASS 2 — emit the preload links and promote the winning tags. | |
| 353 | + $chosen = array(); | |
| 354 | + foreach ( $winners as $w ) { | |
| 355 | + // Idempotency: if this src is already the target of a | |
| 356 | + // rel="preload" as="image" link, still promote the tag but don't | |
| 357 | + // emit a duplicate <link>. | |
| 358 | + $already = (bool) preg_match( | |
| 359 | + '#rel=["\']preload["\'][^>]*as=["\']image["\'][^>]*' . preg_quote( $w['src'], '#' ) . '#i', | |
| 360 | + $existing | |
| 361 | + ); | |
| 362 | + if ( ! $already ) { | |
| 363 | + $preload .= self::preload_link( $w['src'], $w['srcset'], $w['sizes'] ); | |
| 364 | + } | |
| 365 | + // Only <img> winners are promoted in PASS 2 — there is no | |
| 366 | + // fetchpriority/loading attribute to fix on a background element, | |
| 367 | + // and its `order` is offset past every <img> index precisely so it | |
| 368 | + // can never select one for rewriting. | |
| 369 | + if ( empty( $w['background'] ) ) { | |
| 370 | + $chosen[ $w['order'] ] = true; | |
| 371 | + } | |
| 372 | + } | |
| 373 | + | |
| 374 | + // Rewrite only the winning tags. Counting occurrences rather than | |
| 375 | + // matching on tag text, because the same markup can legitimately | |
| 376 | + // appear more than once on a page and only the ranked instance should | |
| 377 | + // be promoted. | |
| 378 | + $seen = -1; | |
| 379 | + $html = preg_replace_callback( | |
| 380 | + '#<img\b[^>]*>#i', | |
| 381 | + static function ( array $m ) use ( &$seen, $chosen ) { | |
| 382 | + ++$seen; | |
| 383 | + if ( ! isset( $chosen[ $seen ] ) ) { | |
| 384 | + return $m[0]; | |
| 385 | + } | |
| 229 | 386 | // Add fetchpriority="high" AND remove any loading="lazy" the |
| 230 | 387 | // theme / WP core left on the LCP image. fetchpriority="high" |
| 231 | 388 | // with loading="lazy" is contradictory — the browser can still |
| 232 | 389 | // defer a lazy image, so preloading it while it stays lazy wins |
| 233 | 390 | // nothing. Stripping lazy is what actually lets the preload land. |
| 234 | - return self::promote_lcp_img( $tag ); | |
| 391 | + return self::promote_lcp_img( $m[0] ); | |
| 235 | 392 | }, |
| 236 | 393 | $html |
| 237 | 394 | ); |
| 238 | 395 | |
| @@ -239,8 +396,331 @@ | ||
| 239 | 396 | return array( (string) $html, $preload ); |
| 240 | 397 | } |
| 241 | 398 | |
| 242 | 399 | /** |
| 400 | + * Collect CSS `background-image` heroes as LCP candidates. | |
| 401 | + * | |
| 402 | + * Only INLINE `style` attributes are read. A background declared in an | |
| 403 | + * external stylesheet is invisible here by design: resolving it would mean | |
| 404 | + * fetching and parsing CSS from inside an output-buffer pass, and the URL a | |
| 405 | + * selector resolves to depends on cascade order we cannot evaluate from | |
| 406 | + * markup. Builders that put the hero in a generated per-post stylesheet are | |
| 407 | + * therefore still unserved — worth doing, but not at this cost. (#247) | |
| 408 | + * | |
| 409 | + * Scores are the element's declared pixel area so a background competes | |
| 410 | + * against an <img> in the SAME units — the whole point being that the | |
| 411 | + * bigger of the two should win regardless of which kind it is. | |
| 412 | + * | |
| 413 | + * @param string $html Full page HTML. | |
| 414 | + * @param string[] $exclusions Substring patterns the user excluded. | |
| 415 | + * @param array<int,array{0:int,1:int}> $skip_ranges Byte ranges of chrome containers. | |
| 416 | + * @return array<int,array{tag:string,src:string,srcset:string,sizes:string,score:float,order:int,background:bool}> | |
| 417 | + */ | |
| 418 | + private static function background_candidates( string $html, array $exclusions, array $skip_ranges ): array { | |
| 419 | + if ( ! preg_match_all( '#<(?:div|section|header|figure|a|span|li|main|article|aside)\b[^>]*\sstyle\s*=\s*(["\']).*?\1[^>]*>#is', $html, $matches, PREG_OFFSET_CAPTURE ) ) { | |
| 420 | + return array(); | |
| 421 | + } | |
| 422 | + | |
| 423 | + $found = array(); | |
| 424 | + foreach ( $matches[0] as $index => $match ) { | |
| 425 | + [ $tag, $offset ] = $match; | |
| 426 | + | |
| 427 | + // The same chrome-container gate as <img>: a background painted | |
| 428 | + // inside <footer>/<nav>/<aside> is never the hero. (FBS-84576) | |
| 429 | + if ( self::offset_in_ranges( $offset, $skip_ranges ) ) { | |
| 430 | + continue; | |
| 431 | + } | |
| 432 | + | |
| 433 | + $style = self::attr( $tag, 'style' ); | |
| 434 | + if ( '' === $style || false === stripos( $style, 'background' ) ) { | |
| 435 | + continue; | |
| 436 | + } | |
| 437 | + | |
| 438 | + $src = self::background_url( $style ); | |
| 439 | + if ( '' === $src ) { | |
| 440 | + continue; | |
| 441 | + } | |
| 442 | + | |
| 443 | + foreach ( $exclusions as $needle ) { | |
| 444 | + if ( '' !== $needle && false !== stripos( $tag, $needle ) ) { | |
| 445 | + continue 2; | |
| 446 | + } | |
| 447 | + } | |
| 448 | + | |
| 449 | + // Same chrome/opt-out gates as <img>. A logo painted as a background | |
| 450 | + // is no more the hero than a logo in an <img>. | |
| 451 | + if ( self::looks_too_small( $tag ) ) { | |
| 452 | + continue; | |
| 453 | + } | |
| 454 | + | |
| 455 | + $area = self::style_area( $style ); | |
| 456 | + if ( 0 === $area ) { | |
| 457 | + // Nothing readable. Deliberately non-zero for the same reason | |
| 458 | + // UNKNOWN_SIZE_SCORE is: an unmeasurable background must still | |
| 459 | + // beat nothing on a page that declares no sizes at all, while | |
| 460 | + // losing to anything we can actually measure. | |
| 461 | + $area = self::UNKNOWN_SIZE_SCORE; | |
| 462 | + } | |
| 463 | + | |
| 464 | + $found[] = array( | |
| 465 | + 'tag' => $tag, | |
| 466 | + 'src' => $src, | |
| 467 | + 'srcset' => '', | |
| 468 | + 'sizes' => '', | |
| 469 | + 'score' => (float) $area, | |
| 470 | + // Offset so a background never ties ahead of an <img> that | |
| 471 | + // appeared earlier in the document; ties still break on order. | |
| 472 | + 'order' => 100000 + $index, | |
| 473 | + 'background' => true, | |
| 474 | + ); | |
| 475 | + } | |
| 476 | + | |
| 477 | + return $found; | |
| 478 | + } | |
| 479 | + | |
| 480 | + /** | |
| 481 | + * Pull a real image URL out of a `background`/`background-image` declaration. | |
| 482 | + * | |
| 483 | + * Returns '' for anything with nothing to fetch: a gradient (which is a | |
| 484 | + * background-image but not a resource), a data: URI, or `none`. | |
| 485 | + */ | |
| 486 | + private static function background_url( string $style ): string { | |
| 487 | + // Decode BEFORE parsing. Builders emit the url() quotes HTML-encoded | |
| 488 | + // inside a style attribute (url("/hero.jpg")), and `"` | |
| 489 | + // carries a semicolon — so splitting the declaration on `;` first | |
| 490 | + // truncated the value to `url("` and found no URL at all. | |
| 491 | + $style = html_entity_decode( $style, ENT_QUOTES ); | |
| 492 | + | |
| 493 | + if ( ! preg_match( '#background(?:-image)?\s*:\s*((?:[^;\'"]|"[^"]*"|\'[^\']*\')+)#i', $style, $decl ) ) { | |
| 494 | + return ''; | |
| 495 | + } | |
| 496 | + if ( ! preg_match( '#url\(\s*(["\']?)(.*?)\1\s*\)#is', $decl[1], $m ) ) { | |
| 497 | + return ''; | |
| 498 | + } | |
| 499 | + $url = trim( $m[2] ); | |
| 500 | + if ( '' === $url || 0 === stripos( $url, 'data:' ) ) { | |
| 501 | + return ''; | |
| 502 | + } | |
| 503 | + return $url; | |
| 504 | + } | |
| 505 | + | |
| 506 | + /** | |
| 507 | + * Declared pixel area from an inline style, or 0 when it can't be read. | |
| 508 | + * | |
| 509 | + * Only px is honoured. A percentage or viewport unit resolves against a | |
| 510 | + * containing block we cannot see from markup, and guessing one produced the | |
| 511 | + * wrong winner more often than declining to. | |
| 512 | + */ | |
| 513 | + private static function style_area( string $style ): int { | |
| 514 | + $w = self::style_px( $style, 'width' ); | |
| 515 | + $h = self::style_px( $style, 'height' ); | |
| 516 | + if ( $w > 0 && $h > 0 ) { | |
| 517 | + return $w * $h; | |
| 518 | + } | |
| 519 | + if ( $w > 0 ) { | |
| 520 | + return (int) round( $w * $w * self::ASSUMED_ASPECT_RATIO ); | |
| 521 | + } | |
| 522 | + return 0; | |
| 523 | + } | |
| 524 | + | |
| 525 | + /** One px-valued CSS length from an inline style, or 0. */ | |
| 526 | + private static function style_px( string $style, string $prop ): int { | |
| 527 | + if ( preg_match( '#(?:^|;)\s*' . preg_quote( $prop, '#' ) . '\s*:\s*(\d+(?:\.\d+)?)px#i', $style, $m ) ) { | |
| 528 | + return (int) round( (float) $m[1] ); | |
| 529 | + } | |
| 530 | + return 0; | |
| 531 | + } | |
| 532 | + | |
| 533 | + /** | |
| 534 | + * How likely is this <img> to be the LCP element? Higher wins. | |
| 535 | + * | |
| 536 | + * Rendered area is the best available proxy, and we can only read what the | |
| 537 | + * markup declares: | |
| 538 | + * | |
| 539 | + * 1. `width` × `height` attributes — the real area, when present. | |
| 540 | + * 2. The largest `srcset` / `data-srcset` candidate width, squared into a | |
| 541 | + * pseudo-area. A responsive hero usually omits width/height but ships | |
| 542 | + * a 1600w+ candidate, which says more about its size than its | |
| 543 | + * position ever did. | |
| 544 | + * 3. Nothing readable → a neutral score, so the image still competes | |
| 545 | + * (matching looks_too_small()'s "don't guess" rule) but loses to any | |
| 546 | + * image we CAN measure as larger. | |
| 547 | + * | |
| 548 | + * @param string $tag The full <img> tag. | |
| 549 | + * @param string $srcset Resolved srcset (may come from data-srcset). | |
| 550 | + */ | |
| 551 | + private static function lcp_score( string $tag, string $srcset ): float { | |
| 552 | + $w = self::attr( $tag, 'width' ); | |
| 553 | + $h = self::attr( $tag, 'height' ); | |
| 554 | + if ( '' !== $w && '' !== $h && is_numeric( $w ) && is_numeric( $h ) ) { | |
| 555 | + return (float) ( (int) $w * (int) $h ); | |
| 556 | + } | |
| 557 | + | |
| 558 | + $widest = self::widest_srcset_width( $srcset ); | |
| 559 | + if ( $widest > 0 ) { | |
| 560 | + // Estimate an AREA, not a square. Squaring the width compared a | |
| 561 | + // pseudo-area against a real one and overstated the width-only | |
| 562 | + // candidate by roughly the inverse of its aspect ratio, so a | |
| 563 | + // 1024w sidebar thumbnail (1 048 576) beat a declared 1200×600 | |
| 564 | + // hero (720 000) — a regression on exactly the mixed pages that | |
| 565 | + // document order used to get right, since the hero usually comes | |
| 566 | + // first. Assuming a 16:9 box keeps both sides in the same units. | |
| 567 | + return round( $widest * $widest * self::ASSUMED_ASPECT_RATIO ); | |
| 568 | + } | |
| 569 | + | |
| 570 | + return (float) self::UNKNOWN_SIZE_SCORE; | |
| 571 | + } | |
| 572 | + | |
| 573 | + /** | |
| 574 | + * Fold the author's own priority signals and document position into an | |
| 575 | + * area score. (FBS-84576) | |
| 576 | + * | |
| 577 | + * Boosts are ADDITIVE, in area units, so they can rescue an image whose | |
| 578 | + * size the markup doesn't declare: a hero with no width/height and no | |
| 579 | + * `w`-descriptor srcset scores UNKNOWN_SIZE_SCORE, and multiplying that | |
| 580 | + * by any factor still loses to a 548×136 logo that declares itself. This | |
| 581 | + * is exactly the live miss — the real hero carried loading="eager" | |
| 582 | + * fetchpriority="high" and lost to three dimension-declaring decoys. | |
| 583 | + * | |
| 584 | + * - fetchpriority="high" is the strongest signal there is: the author | |
| 585 | + * (or WP core's own LCP detection) has already named this image the | |
| 586 | + * hero. Worth a hero-sized area. | |
| 587 | + * - An EXPLICIT loading="eager" is a weaker but deliberate "load me | |
| 588 | + * now" (the default is eager, so writing it out is a choice). | |
| 589 | + * | |
| 590 | + * Position is a light multiplicative weight — earlier is better, but the | |
| 591 | + * spread is capped well under 5× so it can only break near-ties, never | |
| 592 | + * outrank a genuinely larger image further down (the logo-vs-hero case). | |
| 593 | + * | |
| 594 | + * @param float $score Base area score from lcp_score() / style_area(). | |
| 595 | + * @param string $tag The candidate's full tag (for the signal attrs). | |
| 596 | + * @param int $order Document-order index of the candidate. | |
| 597 | + */ | |
| 598 | + private static function weighted_score( float $score, string $tag, int $order ): float { | |
| 599 | + if ( 'high' === strtolower( self::attr( $tag, 'fetchpriority' ) ) ) { | |
| 600 | + $score += self::FETCHPRIORITY_HIGH_BOOST; | |
| 601 | + } | |
| 602 | + if ( 'eager' === strtolower( self::attr( $tag, 'loading' ) ) ) { | |
| 603 | + $score += self::EAGER_BOOST; | |
| 604 | + } | |
| 605 | + return $score * self::position_weight( $order ); | |
| 606 | + } | |
| 607 | + | |
| 608 | + /** | |
| 609 | + * Document-position weight: 1.25 for the first image, easing to 1.0 by | |
| 610 | + * the tenth. The whole spread is 25%, far under the 5× area difference it | |
| 611 | + * must never override — it exists only to keep the old first-wins | |
| 612 | + * behaviour for images we can't tell apart. | |
| 613 | + */ | |
| 614 | + private static function position_weight( int $order ): float { | |
| 615 | + return 1.0 + 0.25 * max( 0.0, 1.0 - $order / 10 ); | |
| 616 | + } | |
| 617 | + | |
| 618 | + /** | |
| 619 | + * Area-unit boost for fetchpriority="high" — roughly a 940×530 hero, so | |
| 620 | + * an explicitly-marked image outranks any mid-page decoy even when its | |
| 621 | + * own size is unreadable, while a genuinely huge unmarked image can still | |
| 622 | + * beat a marked small one. | |
| 623 | + */ | |
| 624 | + private const FETCHPRIORITY_HIGH_BOOST = 500000.0; | |
| 625 | + | |
| 626 | + /** | |
| 627 | + * Area-unit boost for an explicit loading="eager" — roughly 420×240, | |
| 628 | + * enough to break ties in favour of the author's intent without letting | |
| 629 | + * an eager logo outrank a plain hero. | |
| 630 | + */ | |
| 631 | + private const EAGER_BOOST = 100000.0; | |
| 632 | + | |
| 633 | + /** | |
| 634 | + * Byte ranges of <footer>/<nav>/<aside> regions. Nesting-aware per tag | |
| 635 | + * name (a nav inside a nav extends the range); an unclosed open tag | |
| 636 | + * poisons through to the end of the document, which errs on the side of | |
| 637 | + * not preloading — the safe direction, since a wrong preload is worse | |
| 638 | + * than none. (FBS-84576) | |
| 639 | + * | |
| 640 | + * @return array<int,array{0:int,1:int}> [start, end] byte offsets. | |
| 641 | + */ | |
| 642 | + private static function chrome_container_ranges( string $html ): array { | |
| 643 | + $ranges = array(); | |
| 644 | + foreach ( array( 'footer', 'nav', 'aside' ) as $name ) { | |
| 645 | + // (?=[\s/>]) rather than \b: a word boundary sits before the `-` | |
| 646 | + // of a custom element, so `<nav\b` would swallow `<nav-menu>`. | |
| 647 | + if ( ! preg_match_all( '#<(/?)' . $name . '(?=[\s/>])[^>]*>#i', $html, $m, PREG_OFFSET_CAPTURE ) ) { | |
| 648 | + continue; | |
| 649 | + } | |
| 650 | + $depth = 0; | |
| 651 | + $start = 0; | |
| 652 | + foreach ( $m[0] as $i => $match ) { | |
| 653 | + $closing = '' !== $m[1][ $i ][0]; | |
| 654 | + if ( ! $closing ) { | |
| 655 | + if ( 0 === $depth ) { | |
| 656 | + $start = $match[1]; | |
| 657 | + } | |
| 658 | + ++$depth; | |
| 659 | + } elseif ( $depth > 0 ) { | |
| 660 | + --$depth; | |
| 661 | + if ( 0 === $depth ) { | |
| 662 | + $ranges[] = array( $start, $match[1] ); | |
| 663 | + } | |
| 664 | + } | |
| 665 | + } | |
| 666 | + if ( $depth > 0 ) { | |
| 667 | + $ranges[] = array( $start, strlen( $html ) ); | |
| 668 | + } | |
| 669 | + } | |
| 670 | + return $ranges; | |
| 671 | + } | |
| 672 | + | |
| 673 | + /** Does a byte offset fall inside any of the given [start, end] ranges? */ | |
| 674 | + private static function offset_in_ranges( int $offset, array $ranges ): bool { | |
| 675 | + foreach ( $ranges as $range ) { | |
| 676 | + if ( $offset > $range[0] && $offset < $range[1] ) { | |
| 677 | + return true; | |
| 678 | + } | |
| 679 | + } | |
| 680 | + return false; | |
| 681 | + } | |
| 682 | + | |
| 683 | + /** | |
| 684 | + * Score for an image whose size we can't read at all. | |
| 685 | + * | |
| 686 | + * Deliberately non-zero: an unmeasurable image must still beat nothing and | |
| 687 | + * still be preloadable on a page where no image declares its size. But it | |
| 688 | + * sits below a 200×200 declared area (40 000), so anything we CAN measure | |
| 689 | + * as a plausible hero outranks a guess. | |
| 690 | + */ | |
| 691 | + private const UNKNOWN_SIZE_SCORE = 1; | |
| 692 | + | |
| 693 | + /** | |
| 694 | + * Height-to-width ratio assumed when only a `w` descriptor is readable. | |
| 695 | + * | |
| 696 | + * 9/16 — the commonest hero/banner shape, and close enough that a | |
| 697 | + * width-only candidate is compared against a declared w×h area on the | |
| 698 | + * same scale rather than being systematically inflated. | |
| 699 | + */ | |
| 700 | + private const ASSUMED_ASPECT_RATIO = 9 / 16; | |
| 701 | + | |
| 702 | + /** | |
| 703 | + * Largest `w` descriptor in a srcset, or 0 when there isn't one. | |
| 704 | + * | |
| 705 | + * Only `w` descriptors are read. An `x` descriptor (`hero.jpg 2x`) | |
| 706 | + * describes pixel density, not layout width, so it says nothing about | |
| 707 | + * rendered area. | |
| 708 | + */ | |
| 709 | + private static function widest_srcset_width( string $srcset ): int { | |
| 710 | + if ( '' === $srcset ) { | |
| 711 | + return 0; | |
| 712 | + } | |
| 713 | + $widest = 0; | |
| 714 | + foreach ( explode( ',', $srcset ) as $candidate ) { | |
| 715 | + if ( preg_match( '#(\d+)w\s*$#', trim( $candidate ), $m ) ) { | |
| 716 | + $widest = max( $widest, (int) $m[1] ); | |
| 717 | + } | |
| 718 | + } | |
| 719 | + return $widest; | |
| 720 | + } | |
| 721 | + | |
| 722 | + /** | |
| 243 | 723 | * Assemble one <link rel="preload" as="image" fetchpriority="high">. |
| 244 | 724 | * |
| 245 | 725 | * The href/srcset run through the `xspeed_lcp_preload_url` / |
| 246 | 726 | * `xspeed_lcp_preload_srcset` filters first. This is the coordination point |
| @@ -301,9 +781,17 @@ | ||
| 301 | 781 | * Extract a single/double-quoted attribute value from a tag. Returns '' |
| 302 | 782 | * when the attribute is absent. |
| 303 | 783 | */ |
| 304 | 784 | private static function attr( string $tag, string $name ): string { |
| 305 | - if ( preg_match( '#\b' . preg_quote( $name, '#' ) . '=(["\'])(.*?)\1#is', $tag, $m ) ) { | |
| 785 | + // Anchor on a real attribute boundary, not `\b`. A word boundary sits | |
| 786 | + // between the `-` and the `w` of `data-width`, so `\bwidth=` matched | |
| 787 | + // inside it: a lazy-loaded hero carrying `data-width="50" | |
| 788 | + // data-height="50"` was scored 50×50 and rejected by | |
| 789 | + // looks_too_small() — defeating the feature on exactly the images the | |
| 790 | + // data-src/data-srcset handling exists to support. Requiring | |
| 791 | + // whitespace (or the start of the string) before the name means only | |
| 792 | + // a genuine attribute matches. | |
| 793 | + if ( preg_match( '#(?:^|\s)' . preg_quote( $name, '#' ) . '\s*=\s*(["\'])(.*?)\1#is', $tag, $m ) ) { | |
| 306 | 794 | return trim( $m[2] ); |
| 307 | 795 | } |
| 308 | 796 | return ''; |
| 309 | 797 | } |
| @@ -354,13 +842,21 @@ | ||
| 354 | 842 | */ |
| 355 | 843 | private const NON_HERO_MARKERS = array( 'logo', 'icon', 'avatar', 'gravatar', 'spinner', 'emoji', 'site-icon', 'custom-logo' ); |
| 356 | 844 | |
| 357 | 845 | /** |
| 846 | + * Below this declared area (px²) an image is a badge/thumb/divider, never | |
| 847 | + * an LCP hero — 10 000 is a 100×100 square, or a 500×20 strip. Applied | |
| 848 | + * only when BOTH dimensions are readable. (FBS-84576) | |
| 849 | + */ | |
| 850 | + private const MIN_LCP_AREA = 10000; | |
| 851 | + | |
| 852 | + /** | |
| 358 | 853 | * Is this <img> too small / too chrome-like to be the LCP hero? True when |
| 359 | 854 | * either (a) it carries a logo/icon/avatar marker, (b) an explicit |
| 360 | - * `data-no-lcp` opt-out, or (c) BOTH width and height are present and both | |
| 361 | - * are ≤ the threshold. Missing dimensions are NOT guessed — an image whose | |
| 362 | - * size we can't read still competes. (FBS-83553 H1 "logo before hero".) | |
| 855 | + * `data-no-lcp` opt-out, or (c) BOTH width and height are present and | |
| 856 | + * both are ≤ the dimension threshold, or their area is under | |
| 857 | + * MIN_LCP_AREA. Missing dimensions are NOT guessed — an image whose size | |
| 858 | + * we can't read still competes. (FBS-83553 H1 "logo before hero".) | |
| 363 | 859 | */ |
| 364 | 860 | private static function looks_too_small( string $tag ): bool { |
| 365 | 861 | if ( false !== stripos( $tag, 'data-no-lcp' ) ) { |
| 366 | 862 | return true; |
| @@ -376,8 +872,11 @@ | ||
| 376 | 872 | $w = self::attr( $tag, 'width' ); |
| 377 | 873 | $h = self::attr( $tag, 'height' ); |
| 378 | 874 | if ( '' === $w || '' === $h || ! is_numeric( $w ) || ! is_numeric( $h ) ) { |
| 379 | 875 | return false; // unknown size — don't guess; let it compete. |
| 876 | + } | |
| 877 | + if ( (int) $w * (int) $h < self::MIN_LCP_AREA ) { | |
| 878 | + return true; | |
| 380 | 879 | } |
| 381 | 880 | return (int) $w <= self::MIN_LCP_DIMENSION && (int) $h <= self::MIN_LCP_DIMENSION; |
| 382 | 881 | } |
| 383 | 882 | |
