includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 use MediaWiki\Logger\LoggerFactory;
  28 use MediaWiki\ProcOpenError;
  29 use MediaWiki\Session\SessionManager;
  30 use MediaWiki\MediaWikiServices;
  31 use MediaWiki\Shell\Shell;
  32 use Wikimedia\ScopedCallback;
  33 use Wikimedia\Rdbms\DBReplicationWaitError;
  34
  35 /**
  36  * Load an extension
  37  *
  38  * This queues an extension to be loaded through
  39  * the ExtensionRegistry system.
  40  *
  41  * @param string $ext Name of the extension to load
  42  * @param string|null $path Absolute path of where to find the extension.json file
  43  * @since 1.25
  44  */
  45 function wfLoadExtension( $ext, $path = null ) {
  46         if ( !$path ) {
  47                 global $wgExtensionDirectory;
  48                 $path = "$wgExtensionDirectory/$ext/extension.json";
  49         }
  50         ExtensionRegistry::getInstance()->queue( $path );
  51 }
  52
  53 /**
  54  * Load multiple extensions at once
  55  *
  56  * Same as wfLoadExtension, but more efficient if you
  57  * are loading multiple extensions.
  58  *
  59  * If you want to specify custom paths, you should interact with
  60  * ExtensionRegistry directly.
  61  *
  62  * @see wfLoadExtension
  63  * @param string[] $exts Array of extension names to load
  64  * @since 1.25
  65  */
  66 function wfLoadExtensions( array $exts ) {
  67         global $wgExtensionDirectory;
  68         $registry = ExtensionRegistry::getInstance();
  69         foreach ( $exts as $ext ) {
  70                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
  71         }
  72 }
  73
  74 /**
  75  * Load a skin
  76  *
  77  * @see wfLoadExtension
  78  * @param string $skin Name of the extension to load
  79  * @param string|null $path Absolute path of where to find the skin.json file
  80  * @since 1.25
  81  */
  82 function wfLoadSkin( $skin, $path = null ) {
  83         if ( !$path ) {
  84                 global $wgStyleDirectory;
  85                 $path = "$wgStyleDirectory/$skin/skin.json";
  86         }
  87         ExtensionRegistry::getInstance()->queue( $path );
  88 }
  89
  90 /**
  91  * Load multiple skins at once
  92  *
  93  * @see wfLoadExtensions
  94  * @param string[] $skins Array of extension names to load
  95  * @since 1.25
  96  */
  97 function wfLoadSkins( array $skins ) {
  98         global $wgStyleDirectory;
  99         $registry = ExtensionRegistry::getInstance();
 100         foreach ( $skins as $skin ) {
 101                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 102         }
 103 }
 104
 105 /**
 106  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 107  * @param array $a
 108  * @param array $b
 109  * @return array
 110  */
 111 function wfArrayDiff2( $a, $b ) {
 112         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 113 }
 114
 115 /**
 116  * @param array|string $a
 117  * @param array|string $b
 118  * @return int
 119  */
 120 function wfArrayDiff2_cmp( $a, $b ) {
 121         if ( is_string( $a ) && is_string( $b ) ) {
 122                 return strcmp( $a, $b );
 123         } elseif ( count( $a ) !== count( $b ) ) {
 124                 return count( $a ) <=> count( $b );
 125         } else {
 126                 reset( $a );
 127                 reset( $b );
 128                 while ( key( $a ) !== null && key( $b ) !== null ) {
 129                         $valueA = current( $a );
 130                         $valueB = current( $b );
 131                         $cmp = strcmp( $valueA, $valueB );
 132                         if ( $cmp !== 0 ) {
 133                                 return $cmp;
 134                         }
 135                         next( $a );
 136                         next( $b );
 137                 }
 138                 return 0;
 139         }
 140 }
 141
 142 /**
 143  * Like array_filter with ARRAY_FILTER_USE_BOTH, but works pre-5.6.
 144  *
 145  * @param array $arr
 146  * @param callable $callback Will be called with the array value and key (in that order) and
 147  *   should return a bool which will determine whether the array element is kept.
 148  * @return array
 149  */
 150 function wfArrayFilter( array $arr, callable $callback ) {
 151         if ( defined( 'ARRAY_FILTER_USE_BOTH' ) ) {
 152                 return array_filter( $arr, $callback, ARRAY_FILTER_USE_BOTH );
 153         }
 154         $filteredKeys = array_filter( array_keys( $arr ), function ( $key ) use ( $arr, $callback ) {
 155                 return call_user_func( $callback, $arr[$key], $key );
 156         } );
 157         return array_intersect_key( $arr, array_fill_keys( $filteredKeys, true ) );
 158 }
 159
 160 /**
 161  * Like array_filter with ARRAY_FILTER_USE_KEY, but works pre-5.6.
 162  *
 163  * @param array $arr
 164  * @param callable $callback Will be called with the array key and should return a bool which
 165  *   will determine whether the array element is kept.
 166  * @return array
 167  */
 168 function wfArrayFilterByKey( array $arr, callable $callback ) {
 169         return wfArrayFilter( $arr, function ( $val, $key ) use ( $callback ) {
 170                 return call_user_func( $callback, $key );
 171         } );
 172 }
 173
 174 /**
 175  * Appends to second array if $value differs from that in $default
 176  *
 177  * @param string|int $key
 178  * @param mixed $value
 179  * @param mixed $default
 180  * @param array &$changed Array to alter
 181  * @throws MWException
 182  */
 183 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 184         if ( is_null( $changed ) ) {
 185                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 186         }
 187         if ( $default[$key] !== $value ) {
 188                 $changed[$key] = $value;
 189         }
 190 }
 191
 192 /**
 193  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 194  * e.g.
 195  *     wfMergeErrorArrays(
 196  *       [ [ 'x' ] ],
 197  *       [ [ 'x', '2' ] ],
 198  *       [ [ 'x' ] ],
 199  *       [ [ 'y' ] ]
 200  *     );
 201  * returns:
 202  *     [
 203  *       [ 'x', '2' ],
 204  *       [ 'x' ],
 205  *       [ 'y' ]
 206  *     ]
 207  *
 208  * @param array $array1,...
 209  * @return array
 210  */
 211 function wfMergeErrorArrays( /*...*/ ) {
 212         $args = func_get_args();
 213         $out = [];
 214         foreach ( $args as $errors ) {
 215                 foreach ( $errors as $params ) {
 216                         $originalParams = $params;
 217                         if ( $params[0] instanceof MessageSpecifier ) {
 218                                 $msg = $params[0];
 219                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 220                         }
 221                         # @todo FIXME: Sometimes get nested arrays for $params,
 222                         # which leads to E_NOTICEs
 223                         $spec = implode( "\t", $params );
 224                         $out[$spec] = $originalParams;
 225                 }
 226         }
 227         return array_values( $out );
 228 }
 229
 230 /**
 231  * Insert array into another array after the specified *KEY*
 232  *
 233  * @param array $array The array.
 234  * @param array $insert The array to insert.
 235  * @param mixed $after The key to insert after
 236  * @return array
 237  */
 238 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 239         // Find the offset of the element to insert after.
 240         $keys = array_keys( $array );
 241         $offsetByKey = array_flip( $keys );
 242
 243         $offset = $offsetByKey[$after];
 244
 245         // Insert at the specified offset
 246         $before = array_slice( $array, 0, $offset + 1, true );
 247         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 248
 249         $output = $before + $insert + $after;
 250
 251         return $output;
 252 }
 253
 254 /**
 255  * Recursively converts the parameter (an object) to an array with the same data
 256  *
 257  * @param object|array $objOrArray
 258  * @param bool $recursive
 259  * @return array
 260  */
 261 function wfObjectToArray( $objOrArray, $recursive = true ) {
 262         $array = [];
 263         if ( is_object( $objOrArray ) ) {
 264                 $objOrArray = get_object_vars( $objOrArray );
 265         }
 266         foreach ( $objOrArray as $key => $value ) {
 267                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 268                         $value = wfObjectToArray( $value );
 269                 }
 270
 271                 $array[$key] = $value;
 272         }
 273
 274         return $array;
 275 }
 276
 277 /**
 278  * Get a random decimal value between 0 and 1, in a way
 279  * not likely to give duplicate values for any realistic
 280  * number of articles.
 281  *
 282  * @note This is designed for use in relation to Special:RandomPage
 283  *       and the page_random database field.
 284  *
 285  * @return string
 286  */
 287 function wfRandom() {
 288         // The maximum random value is "only" 2^31-1, so get two random
 289         // values to reduce the chance of dupes
 290         $max = mt_getrandmax() + 1;
 291         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 292         return $rand;
 293 }
 294
 295 /**
 296  * Get a random string containing a number of pseudo-random hex characters.
 297  *
 298  * @note This is not secure, if you are trying to generate some sort
 299  *       of token please use MWCryptRand instead.
 300  *
 301  * @param int $length The length of the string to generate
 302  * @return string
 303  * @since 1.20
 304  */
 305 function wfRandomString( $length = 32 ) {
 306         $str = '';
 307         for ( $n = 0; $n < $length; $n += 7 ) {
 308                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 309         }
 310         return substr( $str, 0, $length );
 311 }
 312
 313 /**
 314  * We want some things to be included as literal characters in our title URLs
 315  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 316  * all of the following should be safe:
 317  *
 318  * ;:@&=$-_.+!*'(),
 319  *
 320  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 321  * character which should not be encoded. More importantly, google chrome
 322  * always converts %7E back to ~, and converting it in this function can
 323  * cause a redirect loop (T105265).
 324  *
 325  * But + is not safe because it's used to indicate a space; &= are only safe in
 326  * paths and not in queries (and we don't distinguish here); ' seems kind of
 327  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 328  * is reserved, we don't care.  So the list we unescape is:
 329  *
 330  * ;:@$!*(),/~
 331  *
 332  * However, IIS7 redirects fail when the url contains a colon (see T24709),
 333  * so no fancy : for IIS7.
 334  *
 335  * %2F in the page titles seems to fatally break for some reason.
 336  *
 337  * @param string $s
 338  * @return string
 339  */
 340 function wfUrlencode( $s ) {
 341         static $needle;
 342
 343         if ( is_null( $s ) ) {
 344                 $needle = null;
 345                 return '';
 346         }
 347
 348         if ( is_null( $needle ) ) {
 349                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 350                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 351                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 352                 ) {
 353                         $needle[] = '%3A';
 354                 }
 355         }
 356
 357         $s = urlencode( $s );
 358         $s = str_ireplace(
 359                 $needle,
 360                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 361                 $s
 362         );
 363
 364         return $s;
 365 }
 366
 367 /**
 368  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 369  * "days=7&limit=100". Options in the first array override options in the second.
 370  * Options set to null or false will not be output.
 371  *
 372  * @param array $array1 ( String|Array )
 373  * @param array|null $array2 ( String|Array )
 374  * @param string $prefix
 375  * @return string
 376  */
 377 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 378         if ( !is_null( $array2 ) ) {
 379                 $array1 = $array1 + $array2;
 380         }
 381
 382         $cgi = '';
 383         foreach ( $array1 as $key => $value ) {
 384                 if ( !is_null( $value ) && $value !== false ) {
 385                         if ( $cgi != '' ) {
 386                                 $cgi .= '&';
 387                         }
 388                         if ( $prefix !== '' ) {
 389                                 $key = $prefix . "[$key]";
 390                         }
 391                         if ( is_array( $value ) ) {
 392                                 $firstTime = true;
 393                                 foreach ( $value as $k => $v ) {
 394                                         $cgi .= $firstTime ? '' : '&';
 395                                         if ( is_array( $v ) ) {
 396                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 397                                         } else {
 398                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 399                                         }
 400                                         $firstTime = false;
 401                                 }
 402                         } else {
 403                                 if ( is_object( $value ) ) {
 404                                         $value = $value->__toString();
 405                                 }
 406                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 407                         }
 408                 }
 409         }
 410         return $cgi;
 411 }
 412
 413 /**
 414  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 415  * its argument and returns the same string in array form.  This allows compatibility
 416  * with legacy functions that accept raw query strings instead of nice
 417  * arrays.  Of course, keys and values are urldecode()d.
 418  *
 419  * @param string $query Query string
 420  * @return string[] Array version of input
 421  */
 422 function wfCgiToArray( $query ) {
 423         if ( isset( $query[0] ) && $query[0] == '?' ) {
 424                 $query = substr( $query, 1 );
 425         }
 426         $bits = explode( '&', $query );
 427         $ret = [];
 428         foreach ( $bits as $bit ) {
 429                 if ( $bit === '' ) {
 430                         continue;
 431                 }
 432                 if ( strpos( $bit, '=' ) === false ) {
 433                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 434                         $key = $bit;
 435                         $value = '';
 436                 } else {
 437                         list( $key, $value ) = explode( '=', $bit );
 438                 }
 439                 $key = urldecode( $key );
 440                 $value = urldecode( $value );
 441                 if ( strpos( $key, '[' ) !== false ) {
 442                         $keys = array_reverse( explode( '[', $key ) );
 443                         $key = array_pop( $keys );
 444                         $temp = $value;
 445                         foreach ( $keys as $k ) {
 446                                 $k = substr( $k, 0, -1 );
 447                                 $temp = [ $k => $temp ];
 448                         }
 449                         if ( isset( $ret[$key] ) ) {
 450                                 $ret[$key] = array_merge( $ret[$key], $temp );
 451                         } else {
 452                                 $ret[$key] = $temp;
 453                         }
 454                 } else {
 455                         $ret[$key] = $value;
 456                 }
 457         }
 458         return $ret;
 459 }
 460
 461 /**
 462  * Append a query string to an existing URL, which may or may not already
 463  * have query string parameters already. If so, they will be combined.
 464  *
 465  * @param string $url
 466  * @param string|string[] $query String or associative array
 467  * @return string
 468  */
 469 function wfAppendQuery( $url, $query ) {
 470         if ( is_array( $query ) ) {
 471                 $query = wfArrayToCgi( $query );
 472         }
 473         if ( $query != '' ) {
 474                 // Remove the fragment, if there is one
 475                 $fragment = false;
 476                 $hashPos = strpos( $url, '#' );
 477                 if ( $hashPos !== false ) {
 478                         $fragment = substr( $url, $hashPos );
 479                         $url = substr( $url, 0, $hashPos );
 480                 }
 481
 482                 // Add parameter
 483                 if ( false === strpos( $url, '?' ) ) {
 484                         $url .= '?';
 485                 } else {
 486                         $url .= '&';
 487                 }
 488                 $url .= $query;
 489
 490                 // Put the fragment back
 491                 if ( $fragment !== false ) {
 492                         $url .= $fragment;
 493                 }
 494         }
 495         return $url;
 496 }
 497
 498 /**
 499  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 500  * is correct.
 501  *
 502  * The meaning of the PROTO_* constants is as follows:
 503  * PROTO_HTTP: Output a URL starting with http://
 504  * PROTO_HTTPS: Output a URL starting with https://
 505  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 506  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 507  *    on which protocol was used for the current incoming request
 508  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 509  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 510  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 511  *
 512  * @todo this won't work with current-path-relative URLs
 513  * like "subdir/foo.html", etc.
 514  *
 515  * @param string $url Either fully-qualified or a local path + query
 516  * @param string|int|null $defaultProto One of the PROTO_* constants. Determines the
 517  *    protocol to use if $url or $wgServer is protocol-relative
 518  * @return string|false Fully-qualified URL, current-path-relative URL or false if
 519  *    no valid URL can be constructed
 520  */
 521 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 522         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 523                 $wgHttpsPort;
 524         if ( $defaultProto === PROTO_CANONICAL ) {
 525                 $serverUrl = $wgCanonicalServer;
 526         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 527                 // Make $wgInternalServer fall back to $wgServer if not set
 528                 $serverUrl = $wgInternalServer;
 529         } else {
 530                 $serverUrl = $wgServer;
 531                 if ( $defaultProto === PROTO_CURRENT ) {
 532                         $defaultProto = $wgRequest->getProtocol() . '://';
 533                 }
 534         }
 535
 536         // Analyze $serverUrl to obtain its protocol
 537         $bits = wfParseUrl( $serverUrl );
 538         $serverHasProto = $bits && $bits['scheme'] != '';
 539
 540         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 541                 if ( $serverHasProto ) {
 542                         $defaultProto = $bits['scheme'] . '://';
 543                 } else {
 544                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 545                         // This really isn't supposed to happen. Fall back to HTTP in this
 546                         // ridiculous case.
 547                         $defaultProto = PROTO_HTTP;
 548                 }
 549         }
 550
 551         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 552
 553         if ( substr( $url, 0, 2 ) == '//' ) {
 554                 $url = $defaultProtoWithoutSlashes . $url;
 555         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 556                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 557                 // otherwise leave it alone.
 558                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 559         }
 560
 561         $bits = wfParseUrl( $url );
 562
 563         // ensure proper port for HTTPS arrives in URL
 564         // https://phabricator.wikimedia.org/T67184
 565         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 566                 $bits['port'] = $wgHttpsPort;
 567         }
 568
 569         if ( $bits && isset( $bits['path'] ) ) {
 570                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 571                 return wfAssembleUrl( $bits );
 572         } elseif ( $bits ) {
 573                 # No path to expand
 574                 return $url;
 575         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 576                 # URL is a relative path
 577                 return wfRemoveDotSegments( $url );
 578         }
 579
 580         # Expanded URL is not valid.
 581         return false;
 582 }
 583
 584 /**
 585  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 586  * if you need to edit part of a URL and put it back together.
 587  *
 588  * This is the basic structure used (brackets contain keys for $urlParts):
 589  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 590  *
 591  * @todo Need to integrate this into wfExpandUrl (see T34168)
 592  *
 593  * @since 1.19
 594  * @param array $urlParts URL parts, as output from wfParseUrl
 595  * @return string URL assembled from its component parts
 596  */
 597 function wfAssembleUrl( $urlParts ) {
 598         $result = '';
 599
 600         if ( isset( $urlParts['delimiter'] ) ) {
 601                 if ( isset( $urlParts['scheme'] ) ) {
 602                         $result .= $urlParts['scheme'];
 603                 }
 604
 605                 $result .= $urlParts['delimiter'];
 606         }
 607
 608         if ( isset( $urlParts['host'] ) ) {
 609                 if ( isset( $urlParts['user'] ) ) {
 610                         $result .= $urlParts['user'];
 611                         if ( isset( $urlParts['pass'] ) ) {
 612                                 $result .= ':' . $urlParts['pass'];
 613                         }
 614                         $result .= '@';
 615                 }
 616
 617                 $result .= $urlParts['host'];
 618
 619                 if ( isset( $urlParts['port'] ) ) {
 620                         $result .= ':' . $urlParts['port'];
 621                 }
 622         }
 623
 624         if ( isset( $urlParts['path'] ) ) {
 625                 $result .= $urlParts['path'];
 626         }
 627
 628         if ( isset( $urlParts['query'] ) ) {
 629                 $result .= '?' . $urlParts['query'];
 630         }
 631
 632         if ( isset( $urlParts['fragment'] ) ) {
 633                 $result .= '#' . $urlParts['fragment'];
 634         }
 635
 636         return $result;
 637 }
 638
 639 /**
 640  * Remove all dot-segments in the provided URL path.  For example,
 641  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 642  * RFC3986 section 5.2.4.
 643  *
 644  * @todo Need to integrate this into wfExpandUrl (see T34168)
 645  *
 646  * @since 1.19
 647  *
 648  * @param string $urlPath URL path, potentially containing dot-segments
 649  * @return string URL path with all dot-segments removed
 650  */
 651 function wfRemoveDotSegments( $urlPath ) {
 652         $output = '';
 653         $inputOffset = 0;
 654         $inputLength = strlen( $urlPath );
 655
 656         while ( $inputOffset < $inputLength ) {
 657                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 658                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 659                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 660                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 661                 $trimOutput = false;
 662
 663                 if ( $prefixLengthTwo == './' ) {
 664                         # Step A, remove leading "./"
 665                         $inputOffset += 2;
 666                 } elseif ( $prefixLengthThree == '../' ) {
 667                         # Step A, remove leading "../"
 668                         $inputOffset += 3;
 669                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 670                         # Step B, replace leading "/.$" with "/"
 671                         $inputOffset += 1;
 672                         $urlPath[$inputOffset] = '/';
 673                 } elseif ( $prefixLengthThree == '/./' ) {
 674                         # Step B, replace leading "/./" with "/"
 675                         $inputOffset += 2;
 676                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 677                         # Step C, replace leading "/..$" with "/" and
 678                         # remove last path component in output
 679                         $inputOffset += 2;
 680                         $urlPath[$inputOffset] = '/';
 681                         $trimOutput = true;
 682                 } elseif ( $prefixLengthFour == '/../' ) {
 683                         # Step C, replace leading "/../" with "/" and
 684                         # remove last path component in output
 685                         $inputOffset += 3;
 686                         $trimOutput = true;
 687                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 688                         # Step D, remove "^.$"
 689                         $inputOffset += 1;
 690                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 691                         # Step D, remove "^..$"
 692                         $inputOffset += 2;
 693                 } else {
 694                         # Step E, move leading path segment to output
 695                         if ( $prefixLengthOne == '/' ) {
 696                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 697                         } else {
 698                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 699                         }
 700                         if ( $slashPos === false ) {
 701                                 $output .= substr( $urlPath, $inputOffset );
 702                                 $inputOffset = $inputLength;
 703                         } else {
 704                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 705                                 $inputOffset += $slashPos - $inputOffset;
 706                         }
 707                 }
 708
 709                 if ( $trimOutput ) {
 710                         $slashPos = strrpos( $output, '/' );
 711                         if ( $slashPos === false ) {
 712                                 $output = '';
 713                         } else {
 714                                 $output = substr( $output, 0, $slashPos );
 715                         }
 716                 }
 717         }
 718
 719         return $output;
 720 }
 721
 722 /**
 723  * Returns a regular expression of url protocols
 724  *
 725  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 726  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 727  * @return string
 728  */
 729 function wfUrlProtocols( $includeProtocolRelative = true ) {
 730         global $wgUrlProtocols;
 731
 732         // Cache return values separately based on $includeProtocolRelative
 733         static $withProtRel = null, $withoutProtRel = null;
 734         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 735         if ( !is_null( $cachedValue ) ) {
 736                 return $cachedValue;
 737         }
 738
 739         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 740         // with LocalSettings files from 1.5
 741         if ( is_array( $wgUrlProtocols ) ) {
 742                 $protocols = [];
 743                 foreach ( $wgUrlProtocols as $protocol ) {
 744                         // Filter out '//' if !$includeProtocolRelative
 745                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 746                                 $protocols[] = preg_quote( $protocol, '/' );
 747                         }
 748                 }
 749
 750                 $retval = implode( '|', $protocols );
 751         } else {
 752                 // Ignore $includeProtocolRelative in this case
 753                 // This case exists for pre-1.6 compatibility, and we can safely assume
 754                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 755                 // URLs weren't supported until 1.18
 756                 $retval = $wgUrlProtocols;
 757         }
 758
 759         // Cache return value
 760         if ( $includeProtocolRelative ) {
 761                 $withProtRel = $retval;
 762         } else {
 763                 $withoutProtRel = $retval;
 764         }
 765         return $retval;
 766 }
 767
 768 /**
 769  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 770  * you need a regex that matches all URL protocols but does not match protocol-
 771  * relative URLs
 772  * @return string
 773  */
 774 function wfUrlProtocolsWithoutProtRel() {
 775         return wfUrlProtocols( false );
 776 }
 777
 778 /**
 779  * parse_url() work-alike, but non-broken.  Differences:
 780  *
 781  * 1) Does not raise warnings on bad URLs (just returns false).
 782  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 783  *    protocol-relative URLs) correctly.
 784  * 3) Adds a "delimiter" element to the array (see (2)).
 785  * 4) Verifies that the protocol is on the $wgUrlProtocols whitelist.
 786  * 5) Rejects some invalid URLs that parse_url doesn't, e.g. the empty string or URLs starting with
 787  *    a line feed character.
 788  *
 789  * @param string $url A URL to parse
 790  * @return string[]|bool Bits of the URL in an associative array, or false on failure.
 791  *   Possible fields:
 792  *   - scheme: URI scheme (protocol), e.g. 'http', 'mailto'. Lowercase, always present, but can
 793  *       be an empty string for protocol-relative URLs.
 794  *   - delimiter: either '://', ':' or '//'. Always present.
 795  *   - host: domain name / IP. Always present, but could be an empty string, e.g. for file: URLs.
 796  *   - user: user name, e.g. for HTTP Basic auth URLs such as http://user:pass@example.com/
 797  *       Missing when there is no username.
 798  *   - pass: password, same as above.
 799  *   - path: path including the leading /. Will be missing when empty (e.g. 'http://example.com')
 800  *   - query: query string (as a string; see wfCgiToArray() for parsing it), can be missing.
 801  *   - fragment: the part after #, can be missing.
 802  */
 803 function wfParseUrl( $url ) {
 804         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 805
 806         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 807         // bad that the easiest way to handle them is to just prepend 'http:' and
 808         // strip the protocol out later.
 809         $wasRelative = substr( $url, 0, 2 ) == '//';
 810         if ( $wasRelative ) {
 811                 $url = "http:$url";
 812         }
 813         Wikimedia\suppressWarnings();
 814         $bits = parse_url( $url );
 815         Wikimedia\restoreWarnings();
 816         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 817         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 818         if ( !$bits || !isset( $bits['scheme'] ) ) {
 819                 return false;
 820         }
 821
 822         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 823         $bits['scheme'] = strtolower( $bits['scheme'] );
 824
 825         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 826         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 827                 $bits['delimiter'] = '://';
 828         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 829                 $bits['delimiter'] = ':';
 830                 // parse_url detects for news: and mailto: the host part of an url as path
 831                 // We have to correct this wrong detection
 832                 if ( isset( $bits['path'] ) ) {
 833                         $bits['host'] = $bits['path'];
 834                         $bits['path'] = '';
 835                 }
 836         } else {
 837                 return false;
 838         }
 839
 840         /* Provide an empty host for eg. file:/// urls (see T30627) */
 841         if ( !isset( $bits['host'] ) ) {
 842                 $bits['host'] = '';
 843
 844                 // See T47069
 845                 if ( isset( $bits['path'] ) ) {
 846                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 847                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 848                                 $bits['path'] = '/' . $bits['path'];
 849                         }
 850                 } else {
 851                         $bits['path'] = '';
 852                 }
 853         }
 854
 855         // If the URL was protocol-relative, fix scheme and delimiter
 856         if ( $wasRelative ) {
 857                 $bits['scheme'] = '';
 858                 $bits['delimiter'] = '//';
 859         }
 860         return $bits;
 861 }
 862
 863 /**
 864  * Take a URL, make sure it's expanded to fully qualified, and replace any
 865  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 866  * for more compact display and legibility for local audiences.
 867  *
 868  * @todo handle punycode domains too
 869  *
 870  * @param string $url
 871  * @return string
 872  */
 873 function wfExpandIRI( $url ) {
 874         return preg_replace_callback(
 875                 '/((?:%[89A-F][0-9A-F])+)/i',
 876                 'wfExpandIRI_callback',
 877                 wfExpandUrl( $url )
 878         );
 879 }
 880
 881 /**
 882  * Private callback for wfExpandIRI
 883  * @param array $matches
 884  * @return string
 885  */
 886 function wfExpandIRI_callback( $matches ) {
 887         return urldecode( $matches[1] );
 888 }
 889
 890 /**
 891  * Make URL indexes, appropriate for the el_index field of externallinks.
 892  *
 893  * @param string $url
 894  * @return array
 895  */
 896 function wfMakeUrlIndexes( $url ) {
 897         $bits = wfParseUrl( $url );
 898
 899         // Reverse the labels in the hostname, convert to lower case
 900         // For emails reverse domainpart only
 901         if ( $bits['scheme'] == 'mailto' ) {
 902                 $mailparts = explode( '@', $bits['host'], 2 );
 903                 if ( count( $mailparts ) === 2 ) {
 904                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 905                 } else {
 906                         // No domain specified, don't mangle it
 907                         $domainpart = '';
 908                 }
 909                 $reversedHost = $domainpart . '@' . $mailparts[0];
 910         } else {
 911                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 912         }
 913         // Add an extra dot to the end
 914         // Why? Is it in wrong place in mailto links?
 915         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 916                 $reversedHost .= '.';
 917         }
 918         // Reconstruct the pseudo-URL
 919         $prot = $bits['scheme'];
 920         $index = $prot . $bits['delimiter'] . $reversedHost;
 921         // Leave out user and password. Add the port, path, query and fragment
 922         if ( isset( $bits['port'] ) ) {
 923                 $index .= ':' . $bits['port'];
 924         }
 925         if ( isset( $bits['path'] ) ) {
 926                 $index .= $bits['path'];
 927         } else {
 928                 $index .= '/';
 929         }
 930         if ( isset( $bits['query'] ) ) {
 931                 $index .= '?' . $bits['query'];
 932         }
 933         if ( isset( $bits['fragment'] ) ) {
 934                 $index .= '#' . $bits['fragment'];
 935         }
 936
 937         if ( $prot == '' ) {
 938                 return [ "http:$index", "https:$index" ];
 939         } else {
 940                 return [ $index ];
 941         }
 942 }
 943
 944 /**
 945  * Check whether a given URL has a domain that occurs in a given set of domains
 946  * @param string $url
 947  * @param array $domains Array of domains (strings)
 948  * @return bool True if the host part of $url ends in one of the strings in $domains
 949  */
 950 function wfMatchesDomainList( $url, $domains ) {
 951         $bits = wfParseUrl( $url );
 952         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 953                 $host = '.' . $bits['host'];
 954                 foreach ( (array)$domains as $domain ) {
 955                         $domain = '.' . $domain;
 956                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 957                                 return true;
 958                         }
 959                 }
 960         }
 961         return false;
 962 }
 963
 964 /**
 965  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 966  * In normal operation this is a NOP.
 967  *
 968  * Controlling globals:
 969  * $wgDebugLogFile - points to the log file
 970  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 971  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 972  *
 973  * @since 1.25 support for additional context data
 974  *
 975  * @param string $text
 976  * @param string|bool $dest Destination of the message:
 977  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 978  *     - 'private': excluded from HTML output
 979  *   For backward compatibility, it can also take a boolean:
 980  *     - true: same as 'all'
 981  *     - false: same as 'private'
 982  * @param array $context Additional logging context data
 983  */
 984 function wfDebug( $text, $dest = 'all', array $context = [] ) {
 985         global $wgDebugRawPage, $wgDebugLogPrefix;
 986         global $wgDebugTimestamps;
 987
 988         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 989                 return;
 990         }
 991
 992         $text = trim( $text );
 993
 994         if ( $wgDebugTimestamps ) {
 995                 $context['seconds_elapsed'] = sprintf(
 996                         '%6.4f',
 997                         microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT']
 998                 );
 999                 $context['memory_used'] = sprintf(
1000                         '%5.1fM',
1001                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1002                 );
1003         }
1004
1005         if ( $wgDebugLogPrefix !== '' ) {
1006                 $context['prefix'] = $wgDebugLogPrefix;
1007         }
1008         $context['private'] = ( $dest === false || $dest === 'private' );
1009
1010         $logger = LoggerFactory::getInstance( 'wfDebug' );
1011         $logger->debug( $text, $context );
1012 }
1013
1014 /**
1015  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1016  * @return bool
1017  */
1018 function wfIsDebugRawPage() {
1019         static $cache;
1020         if ( $cache !== null ) {
1021                 return $cache;
1022         }
1023         // Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1024         // phpcs:ignore MediaWiki.Usage.SuperGlobalsUsage.SuperGlobals
1025         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1026                 || (
1027                         isset( $_SERVER['SCRIPT_NAME'] )
1028                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1029                 )
1030         ) {
1031                 $cache = true;
1032         } else {
1033                 $cache = false;
1034         }
1035         return $cache;
1036 }
1037
1038 /**
1039  * Send a line giving PHP memory usage.
1040  *
1041  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1042  */
1043 function wfDebugMem( $exact = false ) {
1044         $mem = memory_get_usage();
1045         if ( !$exact ) {
1046                 $mem = floor( $mem / 1024 ) . ' KiB';
1047         } else {
1048                 $mem .= ' B';
1049         }
1050         wfDebug( "Memory usage: $mem\n" );
1051 }
1052
1053 /**
1054  * Send a line to a supplementary debug log file, if configured, or main debug
1055  * log if not.
1056  *
1057  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1058  * a string filename or an associative array mapping 'destination' to the
1059  * desired filename. The associative array may also contain a 'sample' key
1060  * with an integer value, specifying a sampling factor. Sampled log events
1061  * will be emitted with a 1 in N random chance.
1062  *
1063  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1064  * @since 1.25 support for additional context data
1065  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1066  *
1067  * @param string $logGroup
1068  * @param string $text
1069  * @param string|bool $dest Destination of the message:
1070  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1071  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1072  *       discarded otherwise
1073  *   For backward compatibility, it can also take a boolean:
1074  *     - true: same as 'all'
1075  *     - false: same as 'private'
1076  * @param array $context Additional logging context data
1077  */
1078 function wfDebugLog(
1079         $logGroup, $text, $dest = 'all', array $context = []
1080 ) {
1081         $text = trim( $text );
1082
1083         $logger = LoggerFactory::getInstance( $logGroup );
1084         $context['private'] = ( $dest === false || $dest === 'private' );
1085         $logger->info( $text, $context );
1086 }
1087
1088 /**
1089  * Log for database errors
1090  *
1091  * @since 1.25 support for additional context data
1092  *
1093  * @param string $text Database error message.
1094  * @param array $context Additional logging context data
1095  */
1096 function wfLogDBError( $text, array $context = [] ) {
1097         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1098         $logger->error( trim( $text ), $context );
1099 }
1100
1101 /**
1102  * Throws a warning that $function is deprecated
1103  *
1104  * @param string $function
1105  * @param string|bool $version Version of MediaWiki that the function
1106  *    was deprecated in (Added in 1.19).
1107  * @param string|bool $component Added in 1.19.
1108  * @param int $callerOffset How far up the call stack is the original
1109  *    caller. 2 = function that called the function that called
1110  *    wfDeprecated (Added in 1.20)
1111  *
1112  * @return null
1113  */
1114 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1115         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1116 }
1117
1118 /**
1119  * Send a warning either to the debug log or in a PHP error depending on
1120  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1121  *
1122  * @param string $msg Message to send
1123  * @param int $callerOffset Number of items to go back in the backtrace to
1124  *        find the correct caller (1 = function calling wfWarn, ...)
1125  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1126  *        only used when $wgDevelopmentWarnings is true
1127  */
1128 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1129         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1130 }
1131
1132 /**
1133  * Send a warning as a PHP error and the debug log. This is intended for logging
1134  * warnings in production. For logging development warnings, use WfWarn instead.
1135  *
1136  * @param string $msg Message to send
1137  * @param int $callerOffset Number of items to go back in the backtrace to
1138  *        find the correct caller (1 = function calling wfLogWarning, ...)
1139  * @param int $level PHP error level; defaults to E_USER_WARNING
1140  */
1141 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1142         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1143 }
1144
1145 /**
1146  * Log to a file without getting "file size exceeded" signals.
1147  *
1148  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1149  * send lines to the specified port, prefixed by the specified prefix and a space.
1150  * @since 1.25 support for additional context data
1151  *
1152  * @param string $text
1153  * @param string $file Filename
1154  * @param array $context Additional logging context data
1155  * @throws MWException
1156  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1157  */
1158 function wfErrorLog( $text, $file, array $context = [] ) {
1159         wfDeprecated( __METHOD__, '1.25' );
1160         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1161         $context['destination'] = $file;
1162         $logger->info( trim( $text ), $context );
1163 }
1164
1165 /**
1166  * @todo document
1167  * @todo Move logic to MediaWiki.php
1168  */
1169 function wfLogProfilingData() {
1170         global $wgDebugLogGroups, $wgDebugRawPage;
1171
1172         $context = RequestContext::getMain();
1173         $request = $context->getRequest();
1174
1175         $profiler = Profiler::instance();
1176         $profiler->setContext( $context );
1177         $profiler->logData();
1178
1179         // Send out any buffered statsd metrics as needed
1180         MediaWiki::emitBufferedStatsdData(
1181                 MediaWikiServices::getInstance()->getStatsdDataFactory(),
1182                 $context->getConfig()
1183         );
1184
1185         // Profiling must actually be enabled...
1186         if ( $profiler instanceof ProfilerStub ) {
1187                 return;
1188         }
1189
1190         if ( isset( $wgDebugLogGroups['profileoutput'] )
1191                 && $wgDebugLogGroups['profileoutput'] === false
1192         ) {
1193                 // Explicitly disabled
1194                 return;
1195         }
1196         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1197                 return;
1198         }
1199
1200         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1201         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1202                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1203         }
1204         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1205                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1206         }
1207         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1208                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1209         }
1210         if ( isset( $ctx['forwarded_for'] ) ||
1211                 isset( $ctx['client_ip'] ) ||
1212                 isset( $ctx['from'] ) ) {
1213                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1214         }
1215
1216         // Don't load $wgUser at this late stage just for statistics purposes
1217         // @todo FIXME: We can detect some anons even if it is not loaded.
1218         // See User::getId()
1219         $user = $context->getUser();
1220         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1221
1222         // Command line script uses a FauxRequest object which does not have
1223         // any knowledge about an URL and throw an exception instead.
1224         try {
1225                 $ctx['url'] = urldecode( $request->getRequestURL() );
1226         } catch ( Exception $ignored ) {
1227                 // no-op
1228         }
1229
1230         $ctx['output'] = $profiler->getOutput();
1231
1232         $log = LoggerFactory::getInstance( 'profileoutput' );
1233         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1234 }
1235
1236 /**
1237  * Increment a statistics counter
1238  *
1239  * @param string $key
1240  * @param int $count
1241  * @return void
1242  */
1243 function wfIncrStats( $key, $count = 1 ) {
1244         $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1245         $stats->updateCount( $key, $count );
1246 }
1247
1248 /**
1249  * Check whether the wiki is in read-only mode.
1250  *
1251  * @return bool
1252  */
1253 function wfReadOnly() {
1254         return MediaWikiServices::getInstance()->getReadOnlyMode()
1255                 ->isReadOnly();
1256 }
1257
1258 /**
1259  * Check if the site is in read-only mode and return the message if so
1260  *
1261  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1262  * for replica DB lag. This may result in DB connection being made.
1263  *
1264  * @return string|bool String when in read-only mode; false otherwise
1265  */
1266 function wfReadOnlyReason() {
1267         return MediaWikiServices::getInstance()->getReadOnlyMode()
1268                 ->getReason();
1269 }
1270
1271 /**
1272  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1273  *
1274  * @return string|bool String when in read-only mode; false otherwise
1275  * @since 1.27
1276  */
1277 function wfConfiguredReadOnlyReason() {
1278         return MediaWikiServices::getInstance()->getConfiguredReadOnlyMode()
1279                 ->getReason();
1280 }
1281
1282 /**
1283  * Return a Language object from $langcode
1284  *
1285  * @param Language|string|bool $langcode Either:
1286  *                  - a Language object
1287  *                  - code of the language to get the message for, if it is
1288  *                    a valid code create a language for that language, if
1289  *                    it is a string but not a valid code then make a basic
1290  *                    language object
1291  *                  - a boolean: if it's false then use the global object for
1292  *                    the current user's language (as a fallback for the old parameter
1293  *                    functionality), or if it is true then use global object
1294  *                    for the wiki's content language.
1295  * @return Language
1296  */
1297 function wfGetLangObj( $langcode = false ) {
1298         # Identify which language to get or create a language object for.
1299         # Using is_object here due to Stub objects.
1300         if ( is_object( $langcode ) ) {
1301                 # Great, we already have the object (hopefully)!
1302                 return $langcode;
1303         }
1304
1305         global $wgContLang, $wgLanguageCode;
1306         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1307                 # $langcode is the language code of the wikis content language object.
1308                 # or it is a boolean and value is true
1309                 return $wgContLang;
1310         }
1311
1312         global $wgLang;
1313         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1314                 # $langcode is the language code of user language object.
1315                 # or it was a boolean and value is false
1316                 return $wgLang;
1317         }
1318
1319         $validCodes = array_keys( Language::fetchLanguageNames() );
1320         if ( in_array( $langcode, $validCodes ) ) {
1321                 # $langcode corresponds to a valid language.
1322                 return Language::factory( $langcode );
1323         }
1324
1325         # $langcode is a string, but not a valid language code; use content language.
1326         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1327         return $wgContLang;
1328 }
1329
1330 /**
1331  * This is the function for getting translated interface messages.
1332  *
1333  * @see Message class for documentation how to use them.
1334  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1335  *
1336  * This function replaces all old wfMsg* functions.
1337  *
1338  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1339  * @param string ...$params Normal message parameters
1340  * @return Message
1341  *
1342  * @since 1.17
1343  *
1344  * @see Message::__construct
1345  */
1346 function wfMessage( $key, ...$params ) {
1347         $message = new Message( $key );
1348
1349         // We call Message::params() to reduce code duplication
1350         if ( $params ) {
1351                 $message->params( ...$params );
1352         }
1353
1354         return $message;
1355 }
1356
1357 /**
1358  * This function accepts multiple message keys and returns a message instance
1359  * for the first message which is non-empty. If all messages are empty then an
1360  * instance of the first message key is returned.
1361  *
1362  * @param string|string[] ...$keys Message keys
1363  * @return Message
1364  *
1365  * @since 1.18
1366  *
1367  * @see Message::newFallbackSequence
1368  */
1369 function wfMessageFallback( ...$keys ) {
1370         return Message::newFallbackSequence( ...$keys );
1371 }
1372
1373 /**
1374  * Replace message parameter keys on the given formatted output.
1375  *
1376  * @param string $message
1377  * @param array $args
1378  * @return string
1379  * @private
1380  */
1381 function wfMsgReplaceArgs( $message, $args ) {
1382         # Fix windows line-endings
1383         # Some messages are split with explode("\n", $msg)
1384         $message = str_replace( "\r", '', $message );
1385
1386         // Replace arguments
1387         if ( is_array( $args ) && $args ) {
1388                 if ( is_array( $args[0] ) ) {
1389                         $args = array_values( $args[0] );
1390                 }
1391                 $replacementKeys = [];
1392                 foreach ( $args as $n => $param ) {
1393                         $replacementKeys['$' . ( $n + 1 )] = $param;
1394                 }
1395                 $message = strtr( $message, $replacementKeys );
1396         }
1397
1398         return $message;
1399 }
1400
1401 /**
1402  * Fetch server name for use in error reporting etc.
1403  * Use real server name if available, so we know which machine
1404  * in a server farm generated the current page.
1405  *
1406  * @return string
1407  */
1408 function wfHostname() {
1409         static $host;
1410         if ( is_null( $host ) ) {
1411                 # Hostname overriding
1412                 global $wgOverrideHostname;
1413                 if ( $wgOverrideHostname !== false ) {
1414                         # Set static and skip any detection
1415                         $host = $wgOverrideHostname;
1416                         return $host;
1417                 }
1418
1419                 if ( function_exists( 'posix_uname' ) ) {
1420                         // This function not present on Windows
1421                         $uname = posix_uname();
1422                 } else {
1423                         $uname = false;
1424                 }
1425                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1426                         $host = $uname['nodename'];
1427                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1428                         # Windows computer name
1429                         $host = getenv( 'COMPUTERNAME' );
1430                 } else {
1431                         # This may be a virtual server.
1432                         $host = $_SERVER['SERVER_NAME'];
1433                 }
1434         }
1435         return $host;
1436 }
1437
1438 /**
1439  * Returns a script tag that stores the amount of time it took MediaWiki to
1440  * handle the request in milliseconds as 'wgBackendResponseTime'.
1441  *
1442  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1443  * hostname of the server handling the request.
1444  *
1445  * @param string $nonce Value from OutputPage::getCSPNonce
1446  * @return string|WrappedString HTML
1447  */
1448 function wfReportTime( $nonce = null ) {
1449         global $wgShowHostnames;
1450
1451         $elapsed = ( microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT'] );
1452         // seconds to milliseconds
1453         $responseTime = round( $elapsed * 1000 );
1454         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1455         if ( $wgShowHostnames ) {
1456                 $reportVars['wgHostname'] = wfHostname();
1457         }
1458         return Skin::makeVariablesScript( $reportVars, $nonce );
1459 }
1460
1461 /**
1462  * Safety wrapper for debug_backtrace().
1463  *
1464  * Will return an empty array if debug_backtrace is disabled, otherwise
1465  * the output from debug_backtrace() (trimmed).
1466  *
1467  * @param int $limit This parameter can be used to limit the number of stack frames returned
1468  *
1469  * @return array Array of backtrace information
1470  */
1471 function wfDebugBacktrace( $limit = 0 ) {
1472         static $disabled = null;
1473
1474         if ( is_null( $disabled ) ) {
1475                 $disabled = !function_exists( 'debug_backtrace' );
1476                 if ( $disabled ) {
1477                         wfDebug( "debug_backtrace() is disabled\n" );
1478                 }
1479         }
1480         if ( $disabled ) {
1481                 return [];
1482         }
1483
1484         if ( $limit ) {
1485                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1486         } else {
1487                 return array_slice( debug_backtrace(), 1 );
1488         }
1489 }
1490
1491 /**
1492  * Get a debug backtrace as a string
1493  *
1494  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1495  *   Defaults to $wgCommandLineMode if unset.
1496  * @return string
1497  * @since 1.25 Supports $raw parameter.
1498  */
1499 function wfBacktrace( $raw = null ) {
1500         global $wgCommandLineMode;
1501
1502         if ( $raw === null ) {
1503                 $raw = $wgCommandLineMode;
1504         }
1505
1506         if ( $raw ) {
1507                 $frameFormat = "%s line %s calls %s()\n";
1508                 $traceFormat = "%s";
1509         } else {
1510                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1511                 $traceFormat = "<ul>\n%s</ul>\n";
1512         }
1513
1514         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1515                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1516                 $line = $frame['line'] ?? '-';
1517                 $call = $frame['function'];
1518                 if ( !empty( $frame['class'] ) ) {
1519                         $call = $frame['class'] . $frame['type'] . $call;
1520                 }
1521                 return sprintf( $frameFormat, $file, $line, $call );
1522         }, wfDebugBacktrace() );
1523
1524         return sprintf( $traceFormat, implode( '', $frames ) );
1525 }
1526
1527 /**
1528  * Get the name of the function which called this function
1529  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1530  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1531  * wfGetCaller( 3 ) is the parent of that.
1532  *
1533  * @param int $level
1534  * @return string
1535  */
1536 function wfGetCaller( $level = 2 ) {
1537         $backtrace = wfDebugBacktrace( $level + 1 );
1538         if ( isset( $backtrace[$level] ) ) {
1539                 return wfFormatStackFrame( $backtrace[$level] );
1540         } else {
1541                 return 'unknown';
1542         }
1543 }
1544
1545 /**
1546  * Return a string consisting of callers in the stack. Useful sometimes
1547  * for profiling specific points.
1548  *
1549  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1550  * @return string
1551  */
1552 function wfGetAllCallers( $limit = 3 ) {
1553         $trace = array_reverse( wfDebugBacktrace() );
1554         if ( !$limit || $limit > count( $trace ) - 1 ) {
1555                 $limit = count( $trace ) - 1;
1556         }
1557         $trace = array_slice( $trace, -$limit - 1, $limit );
1558         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1559 }
1560
1561 /**
1562  * Return a string representation of frame
1563  *
1564  * @param array $frame
1565  * @return string
1566  */
1567 function wfFormatStackFrame( $frame ) {
1568         if ( !isset( $frame['function'] ) ) {
1569                 return 'NO_FUNCTION_GIVEN';
1570         }
1571         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1572                 $frame['class'] . $frame['type'] . $frame['function'] :
1573                 $frame['function'];
1574 }
1575
1576 /* Some generic result counters, pulled out of SearchEngine */
1577
1578 /**
1579  * @todo document
1580  *
1581  * @param int $offset
1582  * @param int $limit
1583  * @return string
1584  */
1585 function wfShowingResults( $offset, $limit ) {
1586         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1587 }
1588
1589 /**
1590  * Whether the client accept gzip encoding
1591  *
1592  * Uses the Accept-Encoding header to check if the client supports gzip encoding.
1593  * Use this when considering to send a gzip-encoded response to the client.
1594  *
1595  * @param bool $force Forces another check even if we already have a cached result.
1596  * @return bool
1597  */
1598 function wfClientAcceptsGzip( $force = false ) {
1599         static $result = null;
1600         if ( $result === null || $force ) {
1601                 $result = false;
1602                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1603                         # @todo FIXME: We may want to blacklist some broken browsers
1604                         $m = [];
1605                         if ( preg_match(
1606                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1607                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1608                                         $m
1609                                 )
1610                         ) {
1611                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1612                                         $result = false;
1613                                         return $result;
1614                                 }
1615                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1616                                 $result = true;
1617                         }
1618                 }
1619         }
1620         return $result;
1621 }
1622
1623 /**
1624  * Escapes the given text so that it may be output using addWikiText()
1625  * without any linking, formatting, etc. making its way through. This
1626  * is achieved by substituting certain characters with HTML entities.
1627  * As required by the callers, "<nowiki>" is not used.
1628  *
1629  * @param string $text Text to be escaped
1630  * @return string
1631  */
1632 function wfEscapeWikiText( $text ) {
1633         global $wgEnableMagicLinks;
1634         static $repl = null, $repl2 = null;
1635         if ( $repl === null || defined( 'MW_PARSER_TEST' ) || defined( 'MW_PHPUNIT_TEST' ) ) {
1636                 // Tests depend upon being able to change $wgEnableMagicLinks, so don't cache
1637                 // in those situations
1638                 $repl = [
1639                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1640                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1641                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1642                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1643                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1644                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1645                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1646                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1647                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1648                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1649                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1650                         '__' => '_&#95;', '://' => '&#58;//',
1651                 ];
1652
1653                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1654                 // We have to catch everything "\s" matches in PCRE
1655                 foreach ( $magicLinks as $magic ) {
1656                         $repl["$magic "] = "$magic&#32;";
1657                         $repl["$magic\t"] = "$magic&#9;";
1658                         $repl["$magic\r"] = "$magic&#13;";
1659                         $repl["$magic\n"] = "$magic&#10;";
1660                         $repl["$magic\f"] = "$magic&#12;";
1661                 }
1662
1663                 // And handle protocols that don't use "://"
1664                 global $wgUrlProtocols;
1665                 $repl2 = [];
1666                 foreach ( $wgUrlProtocols as $prot ) {
1667                         if ( substr( $prot, -1 ) === ':' ) {
1668                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1669                         }
1670                 }
1671                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1672         }
1673         $text = substr( strtr( "\n$text", $repl ), 1 );
1674         $text = preg_replace( $repl2, '$1&#58;', $text );
1675         return $text;
1676 }
1677
1678 /**
1679  * Sets dest to source and returns the original value of dest
1680  * If source is NULL, it just returns the value, it doesn't set the variable
1681  * If force is true, it will set the value even if source is NULL
1682  *
1683  * @param mixed &$dest
1684  * @param mixed $source
1685  * @param bool $force
1686  * @return mixed
1687  */
1688 function wfSetVar( &$dest, $source, $force = false ) {
1689         $temp = $dest;
1690         if ( !is_null( $source ) || $force ) {
1691                 $dest = $source;
1692         }
1693         return $temp;
1694 }
1695
1696 /**
1697  * As for wfSetVar except setting a bit
1698  *
1699  * @param int &$dest
1700  * @param int $bit
1701  * @param bool $state
1702  *
1703  * @return bool
1704  */
1705 function wfSetBit( &$dest, $bit, $state = true ) {
1706         $temp = (bool)( $dest & $bit );
1707         if ( !is_null( $state ) ) {
1708                 if ( $state ) {
1709                         $dest |= $bit;
1710                 } else {
1711                         $dest &= ~$bit;
1712                 }
1713         }
1714         return $temp;
1715 }
1716
1717 /**
1718  * A wrapper around the PHP function var_export().
1719  * Either print it or add it to the regular output ($wgOut).
1720  *
1721  * @param mixed $var A PHP variable to dump.
1722  */
1723 function wfVarDump( $var ) {
1724         global $wgOut;
1725         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1726         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1727                 print $s;
1728         } else {
1729                 $wgOut->addHTML( $s );
1730         }
1731 }
1732
1733 /**
1734  * Provide a simple HTTP error.
1735  *
1736  * @param int|string $code
1737  * @param string $label
1738  * @param string $desc
1739  */
1740 function wfHttpError( $code, $label, $desc ) {
1741         global $wgOut;
1742         HttpStatus::header( $code );
1743         if ( $wgOut ) {
1744                 $wgOut->disable();
1745                 $wgOut->sendCacheControl();
1746         }
1747
1748         MediaWiki\HeaderCallback::warnIfHeadersSent();
1749         header( 'Content-type: text/html; charset=utf-8' );
1750         print '<!DOCTYPE html>' .
1751                 '<html><head><title>' .
1752                 htmlspecialchars( $label ) .
1753                 '</title></head><body><h1>' .
1754                 htmlspecialchars( $label ) .
1755                 '</h1><p>' .
1756                 nl2br( htmlspecialchars( $desc ) ) .
1757                 "</p></body></html>\n";
1758 }
1759
1760 /**
1761  * Clear away any user-level output buffers, discarding contents.
1762  *
1763  * Suitable for 'starting afresh', for instance when streaming
1764  * relatively large amounts of data without buffering, or wanting to
1765  * output image files without ob_gzhandler's compression.
1766  *
1767  * The optional $resetGzipEncoding parameter controls suppression of
1768  * the Content-Encoding header sent by ob_gzhandler; by default it
1769  * is left. See comments for wfClearOutputBuffers() for why it would
1770  * be used.
1771  *
1772  * Note that some PHP configuration options may add output buffer
1773  * layers which cannot be removed; these are left in place.
1774  *
1775  * @param bool $resetGzipEncoding
1776  */
1777 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1778         if ( $resetGzipEncoding ) {
1779                 // Suppress Content-Encoding and Content-Length
1780                 // headers from OutputHandler::handle.
1781                 global $wgDisableOutputCompression;
1782                 $wgDisableOutputCompression = true;
1783         }
1784         while ( $status = ob_get_status() ) {
1785                 if ( isset( $status['flags'] ) ) {
1786                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1787                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1788                 } elseif ( isset( $status['del'] ) ) {
1789                         $deleteable = $status['del'];
1790                 } else {
1791                         // Guess that any PHP-internal setting can't be removed.
1792                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1793                 }
1794                 if ( !$deleteable ) {
1795                         // Give up, and hope the result doesn't break
1796                         // output behavior.
1797                         break;
1798                 }
1799                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1800                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1801                         break;
1802                 }
1803                 if ( !ob_end_clean() ) {
1804                         // Could not remove output buffer handler; abort now
1805                         // to avoid getting in some kind of infinite loop.
1806                         break;
1807                 }
1808                 if ( $resetGzipEncoding ) {
1809                         if ( $status['name'] == 'ob_gzhandler' ) {
1810                                 // Reset the 'Content-Encoding' field set by this handler
1811                                 // so we can start fresh.
1812                                 header_remove( 'Content-Encoding' );
1813                                 break;
1814                         }
1815                 }
1816         }
1817 }
1818
1819 /**
1820  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1821  *
1822  * Clear away output buffers, but keep the Content-Encoding header
1823  * produced by ob_gzhandler, if any.
1824  *
1825  * This should be used for HTTP 304 responses, where you need to
1826  * preserve the Content-Encoding header of the real result, but
1827  * also need to suppress the output of ob_gzhandler to keep to spec
1828  * and avoid breaking Firefox in rare cases where the headers and
1829  * body are broken over two packets.
1830  */
1831 function wfClearOutputBuffers() {
1832         wfResetOutputBuffers( false );
1833 }
1834
1835 /**
1836  * Converts an Accept-* header into an array mapping string values to quality
1837  * factors
1838  *
1839  * @param string $accept
1840  * @param string $def Default
1841  * @return float[] Associative array of string => float pairs
1842  */
1843 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1844         # No arg means accept anything (per HTTP spec)
1845         if ( !$accept ) {
1846                 return [ $def => 1.0 ];
1847         }
1848
1849         $prefs = [];
1850
1851         $parts = explode( ',', $accept );
1852
1853         foreach ( $parts as $part ) {
1854                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1855                 $values = explode( ';', trim( $part ) );
1856                 $match = [];
1857                 if ( count( $values ) == 1 ) {
1858                         $prefs[$values[0]] = 1.0;
1859                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1860                         $prefs[$values[0]] = floatval( $match[1] );
1861                 }
1862         }
1863
1864         return $prefs;
1865 }
1866
1867 /**
1868  * Checks if a given MIME type matches any of the keys in the given
1869  * array. Basic wildcards are accepted in the array keys.
1870  *
1871  * Returns the matching MIME type (or wildcard) if a match, otherwise
1872  * NULL if no match.
1873  *
1874  * @param string $type
1875  * @param array $avail
1876  * @return string
1877  * @private
1878  */
1879 function mimeTypeMatch( $type, $avail ) {
1880         if ( array_key_exists( $type, $avail ) ) {
1881                 return $type;
1882         } else {
1883                 $mainType = explode( '/', $type )[0];
1884                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1885                         return "$mainType/*";
1886                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1887                         return '*/*';
1888                 } else {
1889                         return null;
1890                 }
1891         }
1892 }
1893
1894 /**
1895  * Returns the 'best' match between a client's requested internet media types
1896  * and the server's list of available types. Each list should be an associative
1897  * array of type to preference (preference is a float between 0.0 and 1.0).
1898  * Wildcards in the types are acceptable.
1899  *
1900  * @param array $cprefs Client's acceptable type list
1901  * @param array $sprefs Server's offered types
1902  * @return string
1903  *
1904  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1905  * XXX: generalize to negotiate other stuff
1906  */
1907 function wfNegotiateType( $cprefs, $sprefs ) {
1908         $combine = [];
1909
1910         foreach ( array_keys( $sprefs ) as $type ) {
1911                 $subType = explode( '/', $type )[1];
1912                 if ( $subType != '*' ) {
1913                         $ckey = mimeTypeMatch( $type, $cprefs );
1914                         if ( $ckey ) {
1915                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1916                         }
1917                 }
1918         }
1919
1920         foreach ( array_keys( $cprefs ) as $type ) {
1921                 $subType = explode( '/', $type )[1];
1922                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1923                         $skey = mimeTypeMatch( $type, $sprefs );
1924                         if ( $skey ) {
1925                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1926                         }
1927                 }
1928         }
1929
1930         $bestq = 0;
1931         $besttype = null;
1932
1933         foreach ( array_keys( $combine ) as $type ) {
1934                 if ( $combine[$type] > $bestq ) {
1935                         $besttype = $type;
1936                         $bestq = $combine[$type];
1937                 }
1938         }
1939
1940         return $besttype;
1941 }
1942
1943 /**
1944  * Reference-counted warning suppression
1945  *
1946  * @deprecated since 1.26, use Wikimedia\suppressWarnings() directly
1947  * @param bool $end
1948  */
1949 function wfSuppressWarnings( $end = false ) {
1950         Wikimedia\suppressWarnings( $end );
1951 }
1952
1953 /**
1954  * @deprecated since 1.26, use Wikimedia\restoreWarnings() directly
1955  * Restore error level to previous value
1956  */
1957 function wfRestoreWarnings() {
1958         Wikimedia\restoreWarnings();
1959 }
1960
1961 /**
1962  * Get a timestamp string in one of various formats
1963  *
1964  * @param mixed $outputtype A timestamp in one of the supported formats, the
1965  *   function will autodetect which format is supplied and act accordingly.
1966  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
1967  * @return string|bool String / false The same date in the format specified in $outputtype or false
1968  */
1969 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
1970         $ret = MWTimestamp::convert( $outputtype, $ts );
1971         if ( $ret === false ) {
1972                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
1973         }
1974         return $ret;
1975 }
1976
1977 /**
1978  * Return a formatted timestamp, or null if input is null.
1979  * For dealing with nullable timestamp columns in the database.
1980  *
1981  * @param int $outputtype
1982  * @param string $ts
1983  * @return string
1984  */
1985 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
1986         if ( is_null( $ts ) ) {
1987                 return null;
1988         } else {
1989                 return wfTimestamp( $outputtype, $ts );
1990         }
1991 }
1992
1993 /**
1994  * Convenience function; returns MediaWiki timestamp for the present time.
1995  *
1996  * @return string
1997  */
1998 function wfTimestampNow() {
1999         # return NOW
2000         return MWTimestamp::now( TS_MW );
2001 }
2002
2003 /**
2004  * Check if the operating system is Windows
2005  *
2006  * @return bool True if it's Windows, false otherwise.
2007  */
2008 function wfIsWindows() {
2009         static $isWindows = null;
2010         if ( $isWindows === null ) {
2011                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2012         }
2013         return $isWindows;
2014 }
2015
2016 /**
2017  * Check if we are running under HHVM
2018  *
2019  * @return bool
2020  */
2021 function wfIsHHVM() {
2022         return defined( 'HHVM_VERSION' );
2023 }
2024
2025 /**
2026  * Check if we are running from the commandline
2027  *
2028  * @since 1.31
2029  * @return bool
2030  */
2031 function wfIsCLI() {
2032         return PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg';
2033 }
2034
2035 /**
2036  * Tries to get the system directory for temporary files. First
2037  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2038  * environment variables are then checked in sequence, then
2039  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2040  *
2041  * NOTE: When possible, use instead the tmpfile() function to create
2042  * temporary files to avoid race conditions on file creation, etc.
2043  *
2044  * @return string
2045  */
2046 function wfTempDir() {
2047         global $wgTmpDirectory;
2048
2049         if ( $wgTmpDirectory !== false ) {
2050                 return $wgTmpDirectory;
2051         }
2052
2053         return TempFSFile::getUsableTempDirectory();
2054 }
2055
2056 /**
2057  * Make directory, and make all parent directories if they don't exist
2058  *
2059  * @param string $dir Full path to directory to create
2060  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2061  * @param string $caller Optional caller param for debugging.
2062  * @throws MWException
2063  * @return bool
2064  */
2065 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2066         global $wgDirectoryMode;
2067
2068         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2069                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2070         }
2071
2072         if ( !is_null( $caller ) ) {
2073                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2074         }
2075
2076         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2077                 return true;
2078         }
2079
2080         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
2081
2082         if ( is_null( $mode ) ) {
2083                 $mode = $wgDirectoryMode;
2084         }
2085
2086         // Turn off the normal warning, we're doing our own below
2087         Wikimedia\suppressWarnings();
2088         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2089         Wikimedia\restoreWarnings();
2090
2091         if ( !$ok ) {
2092                 // directory may have been created on another request since we last checked
2093                 if ( is_dir( $dir ) ) {
2094                         return true;
2095                 }
2096
2097                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2098                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2099         }
2100         return $ok;
2101 }
2102
2103 /**
2104  * Remove a directory and all its content.
2105  * Does not hide error.
2106  * @param string $dir
2107  */
2108 function wfRecursiveRemoveDir( $dir ) {
2109         wfDebug( __FUNCTION__ . "( $dir )\n" );
2110         // taken from https://secure.php.net/manual/en/function.rmdir.php#98622
2111         if ( is_dir( $dir ) ) {
2112                 $objects = scandir( $dir );
2113                 foreach ( $objects as $object ) {
2114                         if ( $object != "." && $object != ".." ) {
2115                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2116                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2117                                 } else {
2118                                         unlink( $dir . '/' . $object );
2119                                 }
2120                         }
2121                 }
2122                 reset( $objects );
2123                 rmdir( $dir );
2124         }
2125 }
2126
2127 /**
2128  * @param int $nr The number to format
2129  * @param int $acc The number of digits after the decimal point, default 2
2130  * @param bool $round Whether or not to round the value, default true
2131  * @return string
2132  */
2133 function wfPercent( $nr, $acc = 2, $round = true ) {
2134         $ret = sprintf( "%.${acc}f", $nr );
2135         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2136 }
2137
2138 /**
2139  * Safety wrapper around ini_get() for boolean settings.
2140  * The values returned from ini_get() are pre-normalized for settings
2141  * set via php.ini or php_flag/php_admin_flag... but *not*
2142  * for those set via php_value/php_admin_value.
2143  *
2144  * It's fairly common for people to use php_value instead of php_flag,
2145  * which can leave you with an 'off' setting giving a false positive
2146  * for code that just takes the ini_get() return value as a boolean.
2147  *
2148  * To make things extra interesting, setting via php_value accepts
2149  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2150  * Unrecognized values go false... again opposite PHP's own coercion
2151  * from string to bool.
2152  *
2153  * Luckily, 'properly' set settings will always come back as '0' or '1',
2154  * so we only have to worry about them and the 'improper' settings.
2155  *
2156  * I frickin' hate PHP... :P
2157  *
2158  * @param string $setting
2159  * @return bool
2160  */
2161 function wfIniGetBool( $setting ) {
2162         return wfStringToBool( ini_get( $setting ) );
2163 }
2164
2165 /**
2166  * Convert string value to boolean, when the following are interpreted as true:
2167  * - on
2168  * - true
2169  * - yes
2170  * - Any number, except 0
2171  * All other strings are interpreted as false.
2172  *
2173  * @param string $val
2174  * @return bool
2175  * @since 1.31
2176  */
2177 function wfStringToBool( $val ) {
2178         $val = strtolower( $val );
2179         // 'on' and 'true' can't have whitespace around them, but '1' can.
2180         return $val == 'on'
2181                 || $val == 'true'
2182                 || $val == 'yes'
2183                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2184 }
2185
2186 /**
2187  * Version of escapeshellarg() that works better on Windows.
2188  *
2189  * Originally, this fixed the incorrect use of single quotes on Windows
2190  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2191  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2192  *
2193  * @param string $args,... strings to escape and glue together,
2194  *  or a single array of strings parameter
2195  * @return string
2196  * @deprecated since 1.30 use MediaWiki\Shell::escape()
2197  */
2198 function wfEscapeShellArg( /*...*/ ) {
2199         $args = func_get_args();
2200
2201         return call_user_func_array( Shell::class . '::escape', $args );
2202 }
2203
2204 /**
2205  * Execute a shell command, with time and memory limits mirrored from the PHP
2206  * configuration if supported.
2207  *
2208  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2209  *   or an array of unescaped arguments, in which case each value will be escaped
2210  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2211  * @param null|mixed &$retval Optional, will receive the program's exit code.
2212  *   (non-zero is usually failure). If there is an error from
2213  *   read, select, or proc_open(), this will be set to -1.
2214  * @param array $environ Optional environment variables which should be
2215  *   added to the executed command environment.
2216  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2217  *   this overwrites the global wgMaxShell* limits.
2218  * @param array $options Array of options:
2219  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2220  *     including errors from limit.sh
2221  *   - profileMethod: By default this function will profile based on the calling
2222  *     method. Set this to a string for an alternative method to profile from
2223  *
2224  * @return string Collected stdout as a string
2225  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2226  */
2227 function wfShellExec( $cmd, &$retval = null, $environ = [],
2228         $limits = [], $options = []
2229 ) {
2230         if ( Shell::isDisabled() ) {
2231                 $retval = 1;
2232                 // Backwards compatibility be upon us...
2233                 return 'Unable to run external programs, proc_open() is disabled.';
2234         }
2235
2236         if ( is_array( $cmd ) ) {
2237                 $cmd = Shell::escape( $cmd );
2238         }
2239
2240         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2241         $profileMethod = $options['profileMethod'] ?? wfGetCaller();
2242
2243         try {
2244                 $result = Shell::command( [] )
2245                         ->unsafeParams( (array)$cmd )
2246                         ->environment( $environ )
2247                         ->limits( $limits )
2248                         ->includeStderr( $includeStderr )
2249                         ->profileMethod( $profileMethod )
2250                         // For b/c
2251                         ->restrict( Shell::RESTRICT_NONE )
2252                         ->execute();
2253         } catch ( ProcOpenError $ex ) {
2254                 $retval = -1;
2255                 return '';
2256         }
2257
2258         $retval = $result->getExitCode();
2259
2260         return $result->getStdout();
2261 }
2262
2263 /**
2264  * Execute a shell command, returning both stdout and stderr. Convenience
2265  * function, as all the arguments to wfShellExec can become unwieldy.
2266  *
2267  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2268  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2269  *   or an array of unescaped arguments, in which case each value will be escaped
2270  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2271  * @param null|mixed &$retval Optional, will receive the program's exit code.
2272  *   (non-zero is usually failure)
2273  * @param array $environ Optional environment variables which should be
2274  *   added to the executed command environment.
2275  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2276  *   this overwrites the global wgMaxShell* limits.
2277  * @return string Collected stdout and stderr as a string
2278  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2279  */
2280 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2281         return wfShellExec( $cmd, $retval, $environ, $limits,
2282                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2283 }
2284
2285 /**
2286  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2287  * Note that $parameters should be a flat array and an option with an argument
2288  * should consist of two consecutive items in the array (do not use "--option value").
2289  *
2290  * @deprecated since 1.31, use Shell::makeScriptCommand()
2291  *
2292  * @param string $script MediaWiki cli script path
2293  * @param array $parameters Arguments and options to the script
2294  * @param array $options Associative array of options:
2295  *     'php': The path to the php executable
2296  *     'wrapper': Path to a PHP wrapper to handle the maintenance script
2297  * @return string
2298  */
2299 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2300         global $wgPhpCli;
2301         // Give site config file a chance to run the script in a wrapper.
2302         // The caller may likely want to call wfBasename() on $script.
2303         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2304         $cmd = isset( $options['php'] ) ? [ $options['php'] ] : [ $wgPhpCli ];
2305         if ( isset( $options['wrapper'] ) ) {
2306                 $cmd[] = $options['wrapper'];
2307         }
2308         $cmd[] = $script;
2309         // Escape each parameter for shell
2310         return Shell::escape( array_merge( $cmd, $parameters ) );
2311 }
2312
2313 /**
2314  * wfMerge attempts to merge differences between three texts.
2315  * Returns true for a clean merge and false for failure or a conflict.
2316  *
2317  * @param string $old
2318  * @param string $mine
2319  * @param string $yours
2320  * @param string &$result
2321  * @param string &$mergeAttemptResult
2322  * @return bool
2323  */
2324 function wfMerge( $old, $mine, $yours, &$result, &$mergeAttemptResult = null ) {
2325         global $wgDiff3;
2326
2327         # This check may also protect against code injection in
2328         # case of broken installations.
2329         Wikimedia\suppressWarnings();
2330         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2331         Wikimedia\restoreWarnings();
2332
2333         if ( !$haveDiff3 ) {
2334                 wfDebug( "diff3 not found\n" );
2335                 return false;
2336         }
2337
2338         # Make temporary files
2339         $td = wfTempDir();
2340         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2341         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2342         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2343
2344         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2345         #       a newline character. To avoid this, we normalize the trailing whitespace before
2346         #       creating the diff.
2347
2348         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2349         fclose( $oldtextFile );
2350         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2351         fclose( $mytextFile );
2352         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2353         fclose( $yourtextFile );
2354
2355         # Check for a conflict
2356         $cmd = Shell::escape( $wgDiff3, '-a', '--overlap-only', $mytextName,
2357                 $oldtextName, $yourtextName );
2358         $handle = popen( $cmd, 'r' );
2359
2360         $mergeAttemptResult = '';
2361         do {
2362                 $data = fread( $handle, 8192 );
2363                 if ( strlen( $data ) == 0 ) {
2364                         break;
2365                 }
2366                 $mergeAttemptResult .= $data;
2367         } while ( true );
2368         pclose( $handle );
2369
2370         $conflict = $mergeAttemptResult !== '';
2371
2372         # Merge differences
2373         $cmd = Shell::escape( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2374                 $oldtextName, $yourtextName );
2375         $handle = popen( $cmd, 'r' );
2376         $result = '';
2377         do {
2378                 $data = fread( $handle, 8192 );
2379                 if ( strlen( $data ) == 0 ) {
2380                         break;
2381                 }
2382                 $result .= $data;
2383         } while ( true );
2384         pclose( $handle );
2385         unlink( $mytextName );
2386         unlink( $oldtextName );
2387         unlink( $yourtextName );
2388
2389         if ( $result === '' && $old !== '' && !$conflict ) {
2390                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2391                 $conflict = true;
2392         }
2393         return !$conflict;
2394 }
2395
2396 /**
2397  * Returns unified plain-text diff of two texts.
2398  * "Useful" for machine processing of diffs.
2399  *
2400  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2401  *
2402  * @param string $before The text before the changes.
2403  * @param string $after The text after the changes.
2404  * @param string $params Command-line options for the diff command.
2405  * @return string Unified diff of $before and $after
2406  */
2407 function wfDiff( $before, $after, $params = '-u' ) {
2408         if ( $before == $after ) {
2409                 return '';
2410         }
2411
2412         global $wgDiff;
2413         Wikimedia\suppressWarnings();
2414         $haveDiff = $wgDiff && file_exists( $wgDiff );
2415         Wikimedia\restoreWarnings();
2416
2417         # This check may also protect against code injection in
2418         # case of broken installations.
2419         if ( !$haveDiff ) {
2420                 wfDebug( "diff executable not found\n" );
2421                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2422                 $format = new UnifiedDiffFormatter();
2423                 return $format->format( $diffs );
2424         }
2425
2426         # Make temporary files
2427         $td = wfTempDir();
2428         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2429         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2430
2431         fwrite( $oldtextFile, $before );
2432         fclose( $oldtextFile );
2433         fwrite( $newtextFile, $after );
2434         fclose( $newtextFile );
2435
2436         // Get the diff of the two files
2437         $cmd = "$wgDiff " . $params . ' ' . Shell::escape( $oldtextName, $newtextName );
2438
2439         $h = popen( $cmd, 'r' );
2440         if ( !$h ) {
2441                 unlink( $oldtextName );
2442                 unlink( $newtextName );
2443                 throw new Exception( __METHOD__ . '(): popen() failed' );
2444         }
2445
2446         $diff = '';
2447
2448         do {
2449                 $data = fread( $h, 8192 );
2450                 if ( strlen( $data ) == 0 ) {
2451                         break;
2452                 }
2453                 $diff .= $data;
2454         } while ( true );
2455
2456         // Clean up
2457         pclose( $h );
2458         unlink( $oldtextName );
2459         unlink( $newtextName );
2460
2461         // Kill the --- and +++ lines. They're not useful.
2462         $diff_lines = explode( "\n", $diff );
2463         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2464                 unset( $diff_lines[0] );
2465         }
2466         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2467                 unset( $diff_lines[1] );
2468         }
2469
2470         $diff = implode( "\n", $diff_lines );
2471
2472         return $diff;
2473 }
2474
2475 /**
2476  * This function works like "use VERSION" in Perl, the program will die with a
2477  * backtrace if the current version of PHP is less than the version provided
2478  *
2479  * This is useful for extensions which due to their nature are not kept in sync
2480  * with releases, and might depend on other versions of PHP than the main code
2481  *
2482  * Note: PHP might die due to parsing errors in some cases before it ever
2483  *       manages to call this function, such is life
2484  *
2485  * @see perldoc -f use
2486  *
2487  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2488  *
2489  * @deprecated since 1.30
2490  *
2491  * @throws MWException
2492  */
2493 function wfUsePHP( $req_ver ) {
2494         wfDeprecated( __FUNCTION__, '1.30' );
2495         $php_ver = PHP_VERSION;
2496
2497         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2498                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2499         }
2500 }
2501
2502 /**
2503  * This function works like "use VERSION" in Perl except it checks the version
2504  * of MediaWiki, the program will die with a backtrace if the current version
2505  * of MediaWiki is less than the version provided.
2506  *
2507  * This is useful for extensions which due to their nature are not kept in sync
2508  * with releases
2509  *
2510  * Note: Due to the behavior of PHP's version_compare() which is used in this
2511  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2512  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2513  * targeted version number. For example if you wanted to allow any variation
2514  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2515  * not result in the same comparison due to the internal logic of
2516  * version_compare().
2517  *
2518  * @see perldoc -f use
2519  *
2520  * @deprecated since 1.26, use the "requires" property of extension.json
2521  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2522  * @throws MWException
2523  */
2524 function wfUseMW( $req_ver ) {
2525         global $wgVersion;
2526
2527         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2528                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2529         }
2530 }
2531
2532 /**
2533  * Return the final portion of a pathname.
2534  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2535  * https://bugs.php.net/bug.php?id=33898
2536  *
2537  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2538  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2539  *
2540  * @param string $path
2541  * @param string $suffix String to remove if present
2542  * @return string
2543  */
2544 function wfBaseName( $path, $suffix = '' ) {
2545         if ( $suffix == '' ) {
2546                 $encSuffix = '';
2547         } else {
2548                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2549         }
2550
2551         $matches = [];
2552         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2553                 return $matches[1];
2554         } else {
2555                 return '';
2556         }
2557 }
2558
2559 /**
2560  * Generate a relative path name to the given file.
2561  * May explode on non-matching case-insensitive paths,
2562  * funky symlinks, etc.
2563  *
2564  * @param string $path Absolute destination path including target filename
2565  * @param string $from Absolute source path, directory only
2566  * @return string
2567  */
2568 function wfRelativePath( $path, $from ) {
2569         // Normalize mixed input on Windows...
2570         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2571         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2572
2573         // Trim trailing slashes -- fix for drive root
2574         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2575         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2576
2577         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2578         $against = explode( DIRECTORY_SEPARATOR, $from );
2579
2580         if ( $pieces[0] !== $against[0] ) {
2581                 // Non-matching Windows drive letters?
2582                 // Return a full path.
2583                 return $path;
2584         }
2585
2586         // Trim off common prefix
2587         while ( count( $pieces ) && count( $against )
2588                 && $pieces[0] == $against[0] ) {
2589                 array_shift( $pieces );
2590                 array_shift( $against );
2591         }
2592
2593         // relative dots to bump us to the parent
2594         while ( count( $against ) ) {
2595                 array_unshift( $pieces, '..' );
2596                 array_shift( $against );
2597         }
2598
2599         array_push( $pieces, wfBaseName( $path ) );
2600
2601         return implode( DIRECTORY_SEPARATOR, $pieces );
2602 }
2603
2604 /**
2605  * Reset the session id
2606  *
2607  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2608  * @since 1.22
2609  */
2610 function wfResetSessionID() {
2611         wfDeprecated( __FUNCTION__, '1.27' );
2612         $session = SessionManager::getGlobalSession();
2613         $delay = $session->delaySave();
2614
2615         $session->resetId();
2616
2617         // Make sure a session is started, since that's what the old
2618         // wfResetSessionID() did.
2619         if ( session_id() !== $session->getId() ) {
2620                 wfSetupSession( $session->getId() );
2621         }
2622
2623         ScopedCallback::consume( $delay );
2624 }
2625
2626 /**
2627  * Initialise php session
2628  *
2629  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2630  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2631  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2632  *  here), then calling $session->persist().
2633  * @param bool|string $sessionId
2634  */
2635 function wfSetupSession( $sessionId = false ) {
2636         wfDeprecated( __FUNCTION__, '1.27' );
2637
2638         if ( $sessionId ) {
2639                 session_id( $sessionId );
2640         }
2641
2642         $session = SessionManager::getGlobalSession();
2643         $session->persist();
2644
2645         if ( session_id() !== $session->getId() ) {
2646                 session_id( $session->getId() );
2647         }
2648         Wikimedia\quietCall( 'session_start' );
2649 }
2650
2651 /**
2652  * Get an object from the precompiled serialized directory
2653  *
2654  * @param string $name
2655  * @return mixed The variable on success, false on failure
2656  */
2657 function wfGetPrecompiledData( $name ) {
2658         global $IP;
2659
2660         $file = "$IP/serialized/$name";
2661         if ( file_exists( $file ) ) {
2662                 $blob = file_get_contents( $file );
2663                 if ( $blob ) {
2664                         return unserialize( $blob );
2665                 }
2666         }
2667         return false;
2668 }
2669
2670 /**
2671  * @since 1.32
2672  * @param string[] $data Array with string keys/values to export
2673  * @param string $header
2674  * @return string PHP code
2675  */
2676 function wfMakeStaticArrayFile( array $data, $header = 'Automatically generated' ) {
2677         $format = "\t%s => %s,\n";
2678         $code = "<?php\n"
2679                 . "// " . implode( "\n// ", explode( "\n", $header ) ) . "\n"
2680                 . "return [\n";
2681         foreach ( $data as $key => $value ) {
2682                 $code .= sprintf(
2683                         $format,
2684                         var_export( $key, true ),
2685                         var_export( $value, true )
2686                 );
2687         }
2688         $code .= "];\n";
2689         return $code;
2690 }
2691
2692 /**
2693  * Make a cache key for the local wiki.
2694  *
2695  * @deprecated since 1.30 Call makeKey on a BagOStuff instance
2696  * @param string $args,...
2697  * @return string
2698  */
2699 function wfMemcKey( /*...*/ ) {
2700         return call_user_func_array(
2701                 [ ObjectCache::getLocalClusterInstance(), 'makeKey' ],
2702                 func_get_args()
2703         );
2704 }
2705
2706 /**
2707  * Make a cache key for a foreign DB.
2708  *
2709  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2710  *
2711  * @param string $db
2712  * @param string $prefix
2713  * @param string $args,...
2714  * @return string
2715  */
2716 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
2717         $args = array_slice( func_get_args(), 2 );
2718         $keyspace = $prefix ? "$db-$prefix" : $db;
2719         return call_user_func_array(
2720                 [ ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ],
2721                 [ $keyspace, $args ]
2722         );
2723 }
2724
2725 /**
2726  * Make a cache key with database-agnostic prefix.
2727  *
2728  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
2729  * instead. Must have a prefix as otherwise keys that use a database name
2730  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
2731  *
2732  * @deprecated since 1.30 Call makeGlobalKey on a BagOStuff instance
2733  * @since 1.26
2734  * @param string $args,...
2735  * @return string
2736  */
2737 function wfGlobalCacheKey( /*...*/ ) {
2738         return call_user_func_array(
2739                 [ ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ],
2740                 func_get_args()
2741         );
2742 }
2743
2744 /**
2745  * Get an ASCII string identifying this wiki
2746  * This is used as a prefix in memcached keys
2747  *
2748  * @return string
2749  */
2750 function wfWikiID() {
2751         global $wgDBprefix, $wgDBname;
2752         if ( $wgDBprefix ) {
2753                 return "$wgDBname-$wgDBprefix";
2754         } else {
2755                 return $wgDBname;
2756         }
2757 }
2758
2759 /**
2760  * Split a wiki ID into DB name and table prefix
2761  *
2762  * @param string $wiki
2763  *
2764  * @return array
2765  */
2766 function wfSplitWikiID( $wiki ) {
2767         $bits = explode( '-', $wiki, 2 );
2768         if ( count( $bits ) < 2 ) {
2769                 $bits[] = '';
2770         }
2771         return $bits;
2772 }
2773
2774 /**
2775  * Get a Database object.
2776  *
2777  * @param int $db Index of the connection to get. May be DB_MASTER for the
2778  *            master (for write queries), DB_REPLICA for potentially lagged read
2779  *            queries, or an integer >= 0 for a particular server.
2780  *
2781  * @param string|string[] $groups Query groups. An array of group names that this query
2782  *                belongs to. May contain a single string if the query is only
2783  *                in one group.
2784  *
2785  * @param string|bool $wiki The wiki ID, or false for the current wiki
2786  *
2787  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
2788  * will always return the same object, unless the underlying connection or load
2789  * balancer is manually destroyed.
2790  *
2791  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
2792  * updater to ensure that a proper database is being updated.
2793  *
2794  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
2795  *       on an injected instance of LoadBalancer.
2796  *
2797  * @return \Wikimedia\Rdbms\Database
2798  */
2799 function wfGetDB( $db, $groups = [], $wiki = false ) {
2800         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
2801 }
2802
2803 /**
2804  * Get a load balancer object.
2805  *
2806  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancer()
2807  *              or MediaWikiServices::getDBLoadBalancerFactory() instead.
2808  *
2809  * @param string|bool $wiki Wiki ID, or false for the current wiki
2810  * @return \Wikimedia\Rdbms\LoadBalancer
2811  */
2812 function wfGetLB( $wiki = false ) {
2813         if ( $wiki === false ) {
2814                 return MediaWikiServices::getInstance()->getDBLoadBalancer();
2815         } else {
2816                 $factory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2817                 return $factory->getMainLB( $wiki );
2818         }
2819 }
2820
2821 /**
2822  * Get the load balancer factory object
2823  *
2824  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancerFactory() instead.
2825  *
2826  * @return \Wikimedia\Rdbms\LBFactory
2827  */
2828 function wfGetLBFactory() {
2829         return MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2830 }
2831
2832 /**
2833  * Find a file.
2834  * Shortcut for RepoGroup::singleton()->findFile()
2835  *
2836  * @param string|Title $title String or Title object
2837  * @param array $options Associative array of options (see RepoGroup::findFile)
2838  * @return File|bool File, or false if the file does not exist
2839  */
2840 function wfFindFile( $title, $options = [] ) {
2841         return RepoGroup::singleton()->findFile( $title, $options );
2842 }
2843
2844 /**
2845  * Get an object referring to a locally registered file.
2846  * Returns a valid placeholder object if the file does not exist.
2847  *
2848  * @param Title|string $title
2849  * @return LocalFile|null A File, or null if passed an invalid Title
2850  */
2851 function wfLocalFile( $title ) {
2852         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
2853 }
2854
2855 /**
2856  * Should low-performance queries be disabled?
2857  *
2858  * @return bool
2859  * @codeCoverageIgnore
2860  */
2861 function wfQueriesMustScale() {
2862         global $wgMiserMode;
2863         return $wgMiserMode
2864                 || ( SiteStats::pages() > 100000
2865                 && SiteStats::edits() > 1000000
2866                 && SiteStats::users() > 10000 );
2867 }
2868
2869 /**
2870  * Get the path to a specified script file, respecting file
2871  * extensions; this is a wrapper around $wgScriptPath etc.
2872  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
2873  *
2874  * @param string $script Script filename, sans extension
2875  * @return string
2876  */
2877 function wfScript( $script = 'index' ) {
2878         global $wgScriptPath, $wgScript, $wgLoadScript;
2879         if ( $script === 'index' ) {
2880                 return $wgScript;
2881         } elseif ( $script === 'load' ) {
2882                 return $wgLoadScript;
2883         } else {
2884                 return "{$wgScriptPath}/{$script}.php";
2885         }
2886 }
2887
2888 /**
2889  * Get the script URL.
2890  *
2891  * @return string Script URL
2892  */
2893 function wfGetScriptUrl() {
2894         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
2895                 /* as it was called, minus the query string.
2896                  *
2897                  * Some sites use Apache rewrite rules to handle subdomains,
2898                  * and have PHP set up in a weird way that causes PHP_SELF
2899                  * to contain the rewritten URL instead of the one that the
2900                  * outside world sees.
2901                  *
2902                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
2903                  * provides containing the "before" URL.
2904                  */
2905                 return $_SERVER['SCRIPT_NAME'];
2906         } else {
2907                 return $_SERVER['URL'];
2908         }
2909 }
2910
2911 /**
2912  * Convenience function converts boolean values into "true"
2913  * or "false" (string) values
2914  *
2915  * @param bool $value
2916  * @return string
2917  */
2918 function wfBoolToStr( $value ) {
2919         return $value ? 'true' : 'false';
2920 }
2921
2922 /**
2923  * Get a platform-independent path to the null file, e.g. /dev/null
2924  *
2925  * @return string
2926  */
2927 function wfGetNull() {
2928         return wfIsWindows() ? 'NUL' : '/dev/null';
2929 }
2930
2931 /**
2932  * Waits for the replica DBs to catch up to the master position
2933  *
2934  * Use this when updating very large numbers of rows, as in maintenance scripts,
2935  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
2936  *
2937  * By default this waits on the main DB cluster of the current wiki.
2938  * If $cluster is set to "*" it will wait on all DB clusters, including
2939  * external ones. If the lag being waiting on is caused by the code that
2940  * does this check, it makes since to use $ifWritesSince, particularly if
2941  * cluster is "*", to avoid excess overhead.
2942  *
2943  * Never call this function after a big DB write that is still in a transaction.
2944  * This only makes sense after the possible lag inducing changes were committed.
2945  *
2946  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
2947  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
2948  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
2949  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
2950  * @return bool Success (able to connect and no timeouts reached)
2951  * @deprecated since 1.27 Use LBFactory::waitForReplication
2952  */
2953 function wfWaitForSlaves(
2954         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
2955 ) {
2956         if ( $timeout === null ) {
2957                 $timeout = wfIsCLI() ? 60 : 10;
2958         }
2959
2960         if ( $cluster === '*' ) {
2961                 $cluster = false;
2962                 $wiki = false;
2963         } elseif ( $wiki === false ) {
2964                 $wiki = wfWikiID();
2965         }
2966
2967         try {
2968                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2969                 $lbFactory->waitForReplication( [
2970                         'wiki' => $wiki,
2971                         'cluster' => $cluster,
2972                         'timeout' => $timeout,
2973                         // B/C: first argument used to be "max seconds of lag"; ignore such values
2974                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
2975                 ] );
2976         } catch ( DBReplicationWaitError $e ) {
2977                 return false;
2978         }
2979
2980         return true;
2981 }
2982
2983 /**
2984  * Count down from $seconds to zero on the terminal, with a one-second pause
2985  * between showing each number. For use in command-line scripts.
2986  *
2987  * @deprecated since 1.31, use Maintenance::countDown()
2988  *
2989  * @codeCoverageIgnore
2990  * @param int $seconds
2991  */
2992 function wfCountDown( $seconds ) {
2993         wfDeprecated( __FUNCTION__, '1.31' );
2994         for ( $i = $seconds; $i >= 0; $i-- ) {
2995                 if ( $i != $seconds ) {
2996                         echo str_repeat( "\x08", strlen( $i + 1 ) );
2997                 }
2998                 echo $i;
2999                 flush();
3000                 if ( $i ) {
3001                         sleep( 1 );
3002                 }
3003         }
3004         echo "\n";
3005 }
3006
3007 /**
3008  * Replace all invalid characters with '-'.
3009  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
3010  * By default, $wgIllegalFileChars includes ':', '/', '\'.
3011  *
3012  * @param string $name Filename to process
3013  * @return string
3014  */
3015 function wfStripIllegalFilenameChars( $name ) {
3016         global $wgIllegalFileChars;
3017         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3018         $name = preg_replace(
3019                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3020                 '-',
3021                 $name
3022         );
3023         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
3024         $name = wfBaseName( $name );
3025         return $name;
3026 }
3027
3028 /**
3029  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3030  *
3031  * @return int Resulting value of the memory limit.
3032  */
3033 function wfMemoryLimit() {
3034         global $wgMemoryLimit;
3035         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3036         if ( $memlimit != -1 ) {
3037                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3038                 if ( $conflimit == -1 ) {
3039                         wfDebug( "Removing PHP's memory limit\n" );
3040                         Wikimedia\suppressWarnings();
3041                         ini_set( 'memory_limit', $conflimit );
3042                         Wikimedia\restoreWarnings();
3043                         return $conflimit;
3044                 } elseif ( $conflimit > $memlimit ) {
3045                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3046                         Wikimedia\suppressWarnings();
3047                         ini_set( 'memory_limit', $conflimit );
3048                         Wikimedia\restoreWarnings();
3049                         return $conflimit;
3050                 }
3051         }
3052         return $memlimit;
3053 }
3054
3055 /**
3056  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3057  *
3058  * @return int Prior time limit
3059  * @since 1.26
3060  */
3061 function wfTransactionalTimeLimit() {
3062         global $wgTransactionalTimeLimit;
3063
3064         $timeLimit = ini_get( 'max_execution_time' );
3065         // Note that CLI scripts use 0
3066         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3067                 set_time_limit( $wgTransactionalTimeLimit );
3068         }
3069
3070         ignore_user_abort( true ); // ignore client disconnects
3071
3072         return $timeLimit;
3073 }
3074
3075 /**
3076  * Converts shorthand byte notation to integer form
3077  *
3078  * @param string $string
3079  * @param int $default Returned if $string is empty
3080  * @return int
3081  */
3082 function wfShorthandToInteger( $string = '', $default = -1 ) {
3083         $string = trim( $string );
3084         if ( $string === '' ) {
3085                 return $default;
3086         }
3087         $last = $string[strlen( $string ) - 1];
3088         $val = intval( $string );
3089         switch ( $last ) {
3090                 case 'g':
3091                 case 'G':
3092                         $val *= 1024;
3093                         // break intentionally missing
3094                 case 'm':
3095                 case 'M':
3096                         $val *= 1024;
3097                         // break intentionally missing
3098                 case 'k':
3099                 case 'K':
3100                         $val *= 1024;
3101         }
3102
3103         return $val;
3104 }
3105
3106 /**
3107  * Get the normalised IETF language tag
3108  * See unit test for examples.
3109  * See mediawiki.language.bcp47 for the JavaScript implementation.
3110  *
3111  * @deprecated since 1.31, use LanguageCode::bcp47() directly.
3112  *
3113  * @param string $code The language code.
3114  * @return string The language code which complying with BCP 47 standards.
3115  */
3116 function wfBCP47( $code ) {
3117         return LanguageCode::bcp47( $code );
3118 }
3119
3120 /**
3121  * Get a specific cache object.
3122  *
3123  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3124  * @return BagOStuff
3125  */
3126 function wfGetCache( $cacheType ) {
3127         return ObjectCache::getInstance( $cacheType );
3128 }
3129
3130 /**
3131  * Get the main cache object
3132  *
3133  * @return BagOStuff
3134  */
3135 function wfGetMainCache() {
3136         global $wgMainCacheType;
3137         return ObjectCache::getInstance( $wgMainCacheType );
3138 }
3139
3140 /**
3141  * Get the cache object used by the message cache
3142  *
3143  * @return BagOStuff
3144  */
3145 function wfGetMessageCacheStorage() {
3146         global $wgMessageCacheType;
3147         return ObjectCache::getInstance( $wgMessageCacheType );
3148 }
3149
3150 /**
3151  * Call hook functions defined in $wgHooks
3152  *
3153  * @param string $event Event name
3154  * @param array $args Parameters passed to hook functions
3155  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3156  *
3157  * @return bool True if no handler aborted the hook
3158  * @deprecated since 1.25 - use Hooks::run
3159  */
3160 function wfRunHooks( $event, array $args = [], $deprecatedVersion = null ) {
3161         wfDeprecated( __METHOD__, '1.25' );
3162         return Hooks::run( $event, $args, $deprecatedVersion );
3163 }
3164
3165 /**
3166  * Wrapper around php's unpack.
3167  *
3168  * @param string $format The format string (See php's docs)
3169  * @param string $data A binary string of binary data
3170  * @param int|bool $length The minimum length of $data or false. This is to
3171  *      prevent reading beyond the end of $data. false to disable the check.
3172  *
3173  * Also be careful when using this function to read unsigned 32 bit integer
3174  * because php might make it negative.
3175  *
3176  * @throws MWException If $data not long enough, or if unpack fails
3177  * @return array Associative array of the extracted data
3178  */
3179 function wfUnpack( $format, $data, $length = false ) {
3180         if ( $length !== false ) {
3181                 $realLen = strlen( $data );
3182                 if ( $realLen < $length ) {
3183                         throw new MWException( "Tried to use wfUnpack on a "
3184                                 . "string of length $realLen, but needed one "
3185                                 . "of at least length $length."
3186                         );
3187                 }
3188         }
3189
3190         Wikimedia\suppressWarnings();
3191         $result = unpack( $format, $data );
3192         Wikimedia\restoreWarnings();
3193
3194         if ( $result === false ) {
3195                 // If it cannot extract the packed data.
3196                 throw new MWException( "unpack could not unpack binary data" );
3197         }
3198         return $result;
3199 }
3200
3201 /**
3202  * Determine if an image exists on the 'bad image list'.
3203  *
3204  * The format of MediaWiki:Bad_image_list is as follows:
3205  *    * Only list items (lines starting with "*") are considered
3206  *    * The first link on a line must be a link to a bad image
3207  *    * Any subsequent links on the same line are considered to be exceptions,
3208  *      i.e. articles where the image may occur inline.
3209  *
3210  * @param string $name The image name to check
3211  * @param Title|bool $contextTitle The page on which the image occurs, if known
3212  * @param string $blacklist Wikitext of a file blacklist
3213  * @return bool
3214  */
3215 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3216         # Handle redirects; callers almost always hit wfFindFile() anyway,
3217         # so just use that method because it has a fast process cache.
3218         $file = wfFindFile( $name ); // get the final name
3219         $name = $file ? $file->getTitle()->getDBkey() : $name;
3220
3221         # Run the extension hook
3222         $bad = false;
3223         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3224                 return (bool)$bad;
3225         }
3226
3227         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3228         $key = $cache->makeKey(
3229                 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist )
3230         );
3231         $badImages = $cache->get( $key );
3232
3233         if ( $badImages === false ) { // cache miss
3234                 if ( $blacklist === null ) {
3235                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3236                 }
3237                 # Build the list now
3238                 $badImages = [];
3239                 $lines = explode( "\n", $blacklist );
3240                 foreach ( $lines as $line ) {
3241                         # List items only
3242                         if ( substr( $line, 0, 1 ) !== '*' ) {
3243                                 continue;
3244                         }
3245
3246                         # Find all links
3247                         $m = [];
3248                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3249                                 continue;
3250                         }
3251
3252                         $exceptions = [];
3253                         $imageDBkey = false;
3254                         foreach ( $m[1] as $i => $titleText ) {
3255                                 $title = Title::newFromText( $titleText );
3256                                 if ( !is_null( $title ) ) {
3257                                         if ( $i == 0 ) {
3258                                                 $imageDBkey = $title->getDBkey();
3259                                         } else {
3260                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3261                                         }
3262                                 }
3263                         }
3264
3265                         if ( $imageDBkey !== false ) {
3266                                 $badImages[$imageDBkey] = $exceptions;
3267                         }
3268                 }
3269                 $cache->set( $key, $badImages, 60 );
3270         }
3271
3272         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3273         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3274
3275         return $bad;
3276 }
3277
3278 /**
3279  * Determine whether the client at a given source IP is likely to be able to
3280  * access the wiki via HTTPS.
3281  *
3282  * @param string $ip The IPv4/6 address in the normal human-readable form
3283  * @return bool
3284  */
3285 function wfCanIPUseHTTPS( $ip ) {
3286         $canDo = true;
3287         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3288         return !!$canDo;
3289 }
3290
3291 /**
3292  * Determine input string is represents as infinity
3293  *
3294  * @param string $str The string to determine
3295  * @return bool
3296  * @since 1.25
3297  */
3298 function wfIsInfinity( $str ) {
3299         // These are hardcoded elsewhere in MediaWiki (e.g. mediawiki.special.block.js).
3300         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3301         return in_array( $str, $infinityValues );
3302 }
3303
3304 /**
3305  * Returns true if these thumbnail parameters match one that MediaWiki
3306  * requests from file description pages and/or parser output.
3307  *
3308  * $params is considered non-standard if they involve a non-standard
3309  * width or any non-default parameters aside from width and page number.
3310  * The number of possible files with standard parameters is far less than
3311  * that of all combinations; rate-limiting for them can thus be more generious.
3312  *
3313  * @param File $file
3314  * @param array $params
3315  * @return bool
3316  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3317  */
3318 function wfThumbIsStandard( File $file, array $params ) {
3319         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3320
3321         $multipliers = [ 1 ];
3322         if ( $wgResponsiveImages ) {
3323                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3324                 // @see Linker::processResponsiveImages
3325                 $multipliers[] = 1.5;
3326                 $multipliers[] = 2;
3327         }
3328
3329         $handler = $file->getHandler();
3330         if ( !$handler || !isset( $params['width'] ) ) {
3331                 return false;
3332         }
3333
3334         $basicParams = [];
3335         if ( isset( $params['page'] ) ) {
3336                 $basicParams['page'] = $params['page'];
3337         }
3338
3339         $thumbLimits = [];
3340         $imageLimits = [];
3341         // Expand limits to account for multipliers
3342         foreach ( $multipliers as $multiplier ) {
3343                 $thumbLimits = array_merge( $thumbLimits, array_map(
3344                         function ( $width ) use ( $multiplier ) {
3345                                 return round( $width * $multiplier );
3346                         }, $wgThumbLimits )
3347                 );
3348                 $imageLimits = array_merge( $imageLimits, array_map(
3349                         function ( $pair ) use ( $multiplier ) {
3350                                 return [
3351                                         round( $pair[0] * $multiplier ),
3352                                         round( $pair[1] * $multiplier ),
3353                                 ];
3354                         }, $wgImageLimits )
3355                 );
3356         }
3357
3358         // Check if the width matches one of $wgThumbLimits
3359         if ( in_array( $params['width'], $thumbLimits ) ) {
3360                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3361                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3362                 $handler->normaliseParams( $file, $normalParams );
3363         } else {
3364                 // If not, then check if the width matchs one of $wgImageLimits
3365                 $match = false;
3366                 foreach ( $imageLimits as $pair ) {
3367                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3368                         // Decide whether the thumbnail should be scaled on width or height.
3369                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3370                         $handler->normaliseParams( $file, $normalParams );
3371                         // Check if this standard thumbnail size maps to the given width
3372                         if ( $normalParams['width'] == $params['width'] ) {
3373                                 $match = true;
3374                                 break;
3375                         }
3376                 }
3377                 if ( !$match ) {
3378                         return false; // not standard for description pages
3379                 }
3380         }
3381
3382         // Check that the given values for non-page, non-width, params are just defaults
3383         foreach ( $params as $key => $value ) {
3384                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3385                         return false;
3386                 }
3387         }
3388
3389         return true;
3390 }
3391
3392 /**
3393  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3394  *
3395  * Values that exist in both values will be combined with += (all values of the array
3396  * of $newValues will be added to the values of the array of $baseArray, while values,
3397  * that exists in both, the value of $baseArray will be used).
3398  *
3399  * @param array $baseArray The array where you want to add the values of $newValues to
3400  * @param array $newValues An array with new values
3401  * @return array The combined array
3402  * @since 1.26
3403  */
3404 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3405         // First merge items that are in both arrays
3406         foreach ( $baseArray as $name => &$groupVal ) {
3407                 if ( isset( $newValues[$name] ) ) {
3408                         $groupVal += $newValues[$name];
3409                 }
3410         }
3411         // Now add items that didn't exist yet
3412         $baseArray += $newValues;
3413
3414         return $baseArray;
3415 }
3416
3417 /**
3418  * Get system resource usage of current request context.
3419  * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
3420  * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
3421  *
3422  * @since 1.24
3423  * @return array|bool Resource usage data or false if no data available.
3424  */
3425 function wfGetRusage() {
3426         if ( !function_exists( 'getrusage' ) ) {
3427                 return false;
3428         } elseif ( defined( 'HHVM_VERSION' ) && PHP_OS === 'Linux' ) {
3429                 return getrusage( 2 /* RUSAGE_THREAD */ );
3430         } else {
3431                 return getrusage( 0 /* RUSAGE_SELF */ );
3432         }
3433 }