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