includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 use MediaWiki\Logger\LoggerFactory;
  28 use MediaWiki\ProcOpenError;
  29 use MediaWiki\Session\SessionManager;
  30 use MediaWiki\MediaWikiServices;
  31 use MediaWiki\Shell\Shell;
  32 use Wikimedia\ScopedCallback;
  33 use Wikimedia\Rdbms\DBReplicationWaitError;
  34
  35 /**
  36  * Load an extension
  37  *
  38  * This queues an extension to be loaded through
  39  * the ExtensionRegistry system.
  40  *
  41  * @param string $ext Name of the extension to load
  42  * @param string|null $path Absolute path of where to find the extension.json file
  43  * @since 1.25
  44  */
  45 function wfLoadExtension( $ext, $path = null ) {
  46         if ( !$path ) {
  47                 global $wgExtensionDirectory;
  48                 $path = "$wgExtensionDirectory/$ext/extension.json";
  49         }
  50         ExtensionRegistry::getInstance()->queue( $path );
  51 }
  52
  53 /**
  54  * Load multiple extensions at once
  55  *
  56  * Same as wfLoadExtension, but more efficient if you
  57  * are loading multiple extensions.
  58  *
  59  * If you want to specify custom paths, you should interact with
  60  * ExtensionRegistry directly.
  61  *
  62  * @see wfLoadExtension
  63  * @param string[] $exts Array of extension names to load
  64  * @since 1.25
  65  */
  66 function wfLoadExtensions( array $exts ) {
  67         global $wgExtensionDirectory;
  68         $registry = ExtensionRegistry::getInstance();
  69         foreach ( $exts as $ext ) {
  70                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
  71         }
  72 }
  73
  74 /**
  75  * Load a skin
  76  *
  77  * @see wfLoadExtension
  78  * @param string $skin Name of the extension to load
  79  * @param string|null $path Absolute path of where to find the skin.json file
  80  * @since 1.25
  81  */
  82 function wfLoadSkin( $skin, $path = null ) {
  83         if ( !$path ) {
  84                 global $wgStyleDirectory;
  85                 $path = "$wgStyleDirectory/$skin/skin.json";
  86         }
  87         ExtensionRegistry::getInstance()->queue( $path );
  88 }
  89
  90 /**
  91  * Load multiple skins at once
  92  *
  93  * @see wfLoadExtensions
  94  * @param string[] $skins Array of extension names to load
  95  * @since 1.25
  96  */
  97 function wfLoadSkins( array $skins ) {
  98         global $wgStyleDirectory;
  99         $registry = ExtensionRegistry::getInstance();
 100         foreach ( $skins as $skin ) {
 101                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 102         }
 103 }
 104
 105 /**
 106  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 107  * @param array $a
 108  * @param array $b
 109  * @return array
 110  */
 111 function wfArrayDiff2( $a, $b ) {
 112         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 113 }
 114
 115 /**
 116  * @param array|string $a
 117  * @param array|string $b
 118  * @return int
 119  */
 120 function wfArrayDiff2_cmp( $a, $b ) {
 121         if ( is_string( $a ) && is_string( $b ) ) {
 122                 return strcmp( $a, $b );
 123         } elseif ( count( $a ) !== count( $b ) ) {
 124                 return count( $a ) < count( $b ) ? -1 : 1;
 125         } else {
 126                 reset( $a );
 127                 reset( $b );
 128                 while ( key( $a ) !== null && key( $b ) !== null ) {
 129                         $valueA = current( $a );
 130                         $valueB = current( $b );
 131                         $cmp = strcmp( $valueA, $valueB );
 132                         if ( $cmp !== 0 ) {
 133                                 return $cmp;
 134                         }
 135                         next( $a );
 136                         next( $b );
 137                 }
 138                 return 0;
 139         }
 140 }
 141
 142 /**
 143  * Like array_filter with ARRAY_FILTER_USE_BOTH, but works pre-5.6.
 144  *
 145  * @param array $arr
 146  * @param callable $callback Will be called with the array value and key (in that order) and
 147  *   should return a bool which will determine whether the array element is kept.
 148  * @return array
 149  */
 150 function wfArrayFilter( array $arr, callable $callback ) {
 151         if ( defined( 'ARRAY_FILTER_USE_BOTH' ) ) {
 152                 return array_filter( $arr, $callback, ARRAY_FILTER_USE_BOTH );
 153         }
 154         $filteredKeys = array_filter( array_keys( $arr ), function ( $key ) use ( $arr, $callback ) {
 155                 return call_user_func( $callback, $arr[$key], $key );
 156         } );
 157         return array_intersect_key( $arr, array_fill_keys( $filteredKeys, true ) );
 158 }
 159
 160 /**
 161  * Like array_filter with ARRAY_FILTER_USE_KEY, but works pre-5.6.
 162  *
 163  * @param array $arr
 164  * @param callable $callback Will be called with the array key and should return a bool which
 165  *   will determine whether the array element is kept.
 166  * @return array
 167  */
 168 function wfArrayFilterByKey( array $arr, callable $callback ) {
 169         return wfArrayFilter( $arr, function ( $val, $key ) use ( $callback ) {
 170                 return call_user_func( $callback, $key );
 171         } );
 172 }
 173
 174 /**
 175  * Appends to second array if $value differs from that in $default
 176  *
 177  * @param string|int $key
 178  * @param mixed $value
 179  * @param mixed $default
 180  * @param array &$changed Array to alter
 181  * @throws MWException
 182  */
 183 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 184         if ( is_null( $changed ) ) {
 185                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 186         }
 187         if ( $default[$key] !== $value ) {
 188                 $changed[$key] = $value;
 189         }
 190 }
 191
 192 /**
 193  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 194  * e.g.
 195  *     wfMergeErrorArrays(
 196  *       [ [ 'x' ] ],
 197  *       [ [ 'x', '2' ] ],
 198  *       [ [ 'x' ] ],
 199  *       [ [ 'y' ] ]
 200  *     );
 201  * returns:
 202  *     [
 203  *       [ 'x', '2' ],
 204  *       [ 'x' ],
 205  *       [ 'y' ]
 206  *     ]
 207  *
 208  * @param array $array1,...
 209  * @return array
 210  */
 211 function wfMergeErrorArrays( /*...*/ ) {
 212         $args = func_get_args();
 213         $out = [];
 214         foreach ( $args as $errors ) {
 215                 foreach ( $errors as $params ) {
 216                         $originalParams = $params;
 217                         if ( $params[0] instanceof MessageSpecifier ) {
 218                                 $msg = $params[0];
 219                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 220                         }
 221                         # @todo FIXME: Sometimes get nested arrays for $params,
 222                         # which leads to E_NOTICEs
 223                         $spec = implode( "\t", $params );
 224                         $out[$spec] = $originalParams;
 225                 }
 226         }
 227         return array_values( $out );
 228 }
 229
 230 /**
 231  * Insert array into another array after the specified *KEY*
 232  *
 233  * @param array $array The array.
 234  * @param array $insert The array to insert.
 235  * @param mixed $after The key to insert after
 236  * @return array
 237  */
 238 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 239         // Find the offset of the element to insert after.
 240         $keys = array_keys( $array );
 241         $offsetByKey = array_flip( $keys );
 242
 243         $offset = $offsetByKey[$after];
 244
 245         // Insert at the specified offset
 246         $before = array_slice( $array, 0, $offset + 1, true );
 247         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 248
 249         $output = $before + $insert + $after;
 250
 251         return $output;
 252 }
 253
 254 /**
 255  * Recursively converts the parameter (an object) to an array with the same data
 256  *
 257  * @param object|array $objOrArray
 258  * @param bool $recursive
 259  * @return array
 260  */
 261 function wfObjectToArray( $objOrArray, $recursive = true ) {
 262         $array = [];
 263         if ( is_object( $objOrArray ) ) {
 264                 $objOrArray = get_object_vars( $objOrArray );
 265         }
 266         foreach ( $objOrArray as $key => $value ) {
 267                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 268                         $value = wfObjectToArray( $value );
 269                 }
 270
 271                 $array[$key] = $value;
 272         }
 273
 274         return $array;
 275 }
 276
 277 /**
 278  * Get a random decimal value between 0 and 1, in a way
 279  * not likely to give duplicate values for any realistic
 280  * number of articles.
 281  *
 282  * @note This is designed for use in relation to Special:RandomPage
 283  *       and the page_random database field.
 284  *
 285  * @return string
 286  */
 287 function wfRandom() {
 288         // The maximum random value is "only" 2^31-1, so get two random
 289         // values to reduce the chance of dupes
 290         $max = mt_getrandmax() + 1;
 291         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 292         return $rand;
 293 }
 294
 295 /**
 296  * Get a random string containing a number of pseudo-random hex characters.
 297  *
 298  * @note This is not secure, if you are trying to generate some sort
 299  *       of token please use MWCryptRand instead.
 300  *
 301  * @param int $length The length of the string to generate
 302  * @return string
 303  * @since 1.20
 304  */
 305 function wfRandomString( $length = 32 ) {
 306         $str = '';
 307         for ( $n = 0; $n < $length; $n += 7 ) {
 308                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 309         }
 310         return substr( $str, 0, $length );
 311 }
 312
 313 /**
 314  * We want some things to be included as literal characters in our title URLs
 315  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 316  * all of the following should be safe:
 317  *
 318  * ;:@&=$-_.+!*'(),
 319  *
 320  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 321  * character which should not be encoded. More importantly, google chrome
 322  * always converts %7E back to ~, and converting it in this function can
 323  * cause a redirect loop (T105265).
 324  *
 325  * But + is not safe because it's used to indicate a space; &= are only safe in
 326  * paths and not in queries (and we don't distinguish here); ' seems kind of
 327  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 328  * is reserved, we don't care.  So the list we unescape is:
 329  *
 330  * ;:@$!*(),/~
 331  *
 332  * However, IIS7 redirects fail when the url contains a colon (see T24709),
 333  * so no fancy : for IIS7.
 334  *
 335  * %2F in the page titles seems to fatally break for some reason.
 336  *
 337  * @param string $s
 338  * @return string
 339  */
 340 function wfUrlencode( $s ) {
 341         static $needle;
 342
 343         if ( is_null( $s ) ) {
 344                 $needle = null;
 345                 return '';
 346         }
 347
 348         if ( is_null( $needle ) ) {
 349                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 350                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 351                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 352                 ) {
 353                         $needle[] = '%3A';
 354                 }
 355         }
 356
 357         $s = urlencode( $s );
 358         $s = str_ireplace(
 359                 $needle,
 360                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 361                 $s
 362         );
 363
 364         return $s;
 365 }
 366
 367 /**
 368  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 369  * "days=7&limit=100". Options in the first array override options in the second.
 370  * Options set to null or false will not be output.
 371  *
 372  * @param array $array1 ( String|Array )
 373  * @param array|null $array2 ( String|Array )
 374  * @param string $prefix
 375  * @return string
 376  */
 377 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 378         if ( !is_null( $array2 ) ) {
 379                 $array1 = $array1 + $array2;
 380         }
 381
 382         $cgi = '';
 383         foreach ( $array1 as $key => $value ) {
 384                 if ( !is_null( $value ) && $value !== false ) {
 385                         if ( $cgi != '' ) {
 386                                 $cgi .= '&';
 387                         }
 388                         if ( $prefix !== '' ) {
 389                                 $key = $prefix . "[$key]";
 390                         }
 391                         if ( is_array( $value ) ) {
 392                                 $firstTime = true;
 393                                 foreach ( $value as $k => $v ) {
 394                                         $cgi .= $firstTime ? '' : '&';
 395                                         if ( is_array( $v ) ) {
 396                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 397                                         } else {
 398                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 399                                         }
 400                                         $firstTime = false;
 401                                 }
 402                         } else {
 403                                 if ( is_object( $value ) ) {
 404                                         $value = $value->__toString();
 405                                 }
 406                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 407                         }
 408                 }
 409         }
 410         return $cgi;
 411 }
 412
 413 /**
 414  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 415  * its argument and returns the same string in array form.  This allows compatibility
 416  * with legacy functions that accept raw query strings instead of nice
 417  * arrays.  Of course, keys and values are urldecode()d.
 418  *
 419  * @param string $query Query string
 420  * @return string[] Array version of input
 421  */
 422 function wfCgiToArray( $query ) {
 423         if ( isset( $query[0] ) && $query[0] == '?' ) {
 424                 $query = substr( $query, 1 );
 425         }
 426         $bits = explode( '&', $query );
 427         $ret = [];
 428         foreach ( $bits as $bit ) {
 429                 if ( $bit === '' ) {
 430                         continue;
 431                 }
 432                 if ( strpos( $bit, '=' ) === false ) {
 433                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 434                         $key = $bit;
 435                         $value = '';
 436                 } else {
 437                         list( $key, $value ) = explode( '=', $bit );
 438                 }
 439                 $key = urldecode( $key );
 440                 $value = urldecode( $value );
 441                 if ( strpos( $key, '[' ) !== false ) {
 442                         $keys = array_reverse( explode( '[', $key ) );
 443                         $key = array_pop( $keys );
 444                         $temp = $value;
 445                         foreach ( $keys as $k ) {
 446                                 $k = substr( $k, 0, -1 );
 447                                 $temp = [ $k => $temp ];
 448                         }
 449                         if ( isset( $ret[$key] ) ) {
 450                                 $ret[$key] = array_merge( $ret[$key], $temp );
 451                         } else {
 452                                 $ret[$key] = $temp;
 453                         }
 454                 } else {
 455                         $ret[$key] = $value;
 456                 }
 457         }
 458         return $ret;
 459 }
 460
 461 /**
 462  * Append a query string to an existing URL, which may or may not already
 463  * have query string parameters already. If so, they will be combined.
 464  *
 465  * @param string $url
 466  * @param string|string[] $query String or associative array
 467  * @return string
 468  */
 469 function wfAppendQuery( $url, $query ) {
 470         if ( is_array( $query ) ) {
 471                 $query = wfArrayToCgi( $query );
 472         }
 473         if ( $query != '' ) {
 474                 // Remove the fragment, if there is one
 475                 $fragment = false;
 476                 $hashPos = strpos( $url, '#' );
 477                 if ( $hashPos !== false ) {
 478                         $fragment = substr( $url, $hashPos );
 479                         $url = substr( $url, 0, $hashPos );
 480                 }
 481
 482                 // Add parameter
 483                 if ( false === strpos( $url, '?' ) ) {
 484                         $url .= '?';
 485                 } else {
 486                         $url .= '&';
 487                 }
 488                 $url .= $query;
 489
 490                 // Put the fragment back
 491                 if ( $fragment !== false ) {
 492                         $url .= $fragment;
 493                 }
 494         }
 495         return $url;
 496 }
 497
 498 /**
 499  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 500  * is correct.
 501  *
 502  * The meaning of the PROTO_* constants is as follows:
 503  * PROTO_HTTP: Output a URL starting with http://
 504  * PROTO_HTTPS: Output a URL starting with https://
 505  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 506  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 507  *    on which protocol was used for the current incoming request
 508  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 509  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 510  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 511  *
 512  * @todo this won't work with current-path-relative URLs
 513  * like "subdir/foo.html", etc.
 514  *
 515  * @param string $url Either fully-qualified or a local path + query
 516  * @param string|int|null $defaultProto One of the PROTO_* constants. Determines the
 517  *    protocol to use if $url or $wgServer is protocol-relative
 518  * @return string|false Fully-qualified URL, current-path-relative URL or false if
 519  *    no valid URL can be constructed
 520  */
 521 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 522         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 523                 $wgHttpsPort;
 524         if ( $defaultProto === PROTO_CANONICAL ) {
 525                 $serverUrl = $wgCanonicalServer;
 526         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 527                 // Make $wgInternalServer fall back to $wgServer if not set
 528                 $serverUrl = $wgInternalServer;
 529         } else {
 530                 $serverUrl = $wgServer;
 531                 if ( $defaultProto === PROTO_CURRENT ) {
 532                         $defaultProto = $wgRequest->getProtocol() . '://';
 533                 }
 534         }
 535
 536         // Analyze $serverUrl to obtain its protocol
 537         $bits = wfParseUrl( $serverUrl );
 538         $serverHasProto = $bits && $bits['scheme'] != '';
 539
 540         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 541                 if ( $serverHasProto ) {
 542                         $defaultProto = $bits['scheme'] . '://';
 543                 } else {
 544                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 545                         // This really isn't supposed to happen. Fall back to HTTP in this
 546                         // ridiculous case.
 547                         $defaultProto = PROTO_HTTP;
 548                 }
 549         }
 550
 551         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 552
 553         if ( substr( $url, 0, 2 ) == '//' ) {
 554                 $url = $defaultProtoWithoutSlashes . $url;
 555         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 556                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 557                 // otherwise leave it alone.
 558                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 559         }
 560
 561         $bits = wfParseUrl( $url );
 562
 563         // ensure proper port for HTTPS arrives in URL
 564         // https://phabricator.wikimedia.org/T67184
 565         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 566                 $bits['port'] = $wgHttpsPort;
 567         }
 568
 569         if ( $bits && isset( $bits['path'] ) ) {
 570                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 571                 return wfAssembleUrl( $bits );
 572         } elseif ( $bits ) {
 573                 # No path to expand
 574                 return $url;
 575         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 576                 # URL is a relative path
 577                 return wfRemoveDotSegments( $url );
 578         }
 579
 580         # Expanded URL is not valid.
 581         return false;
 582 }
 583
 584 /**
 585  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 586  * if you need to edit part of a URL and put it back together.
 587  *
 588  * This is the basic structure used (brackets contain keys for $urlParts):
 589  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 590  *
 591  * @todo Need to integrate this into wfExpandUrl (see T34168)
 592  *
 593  * @since 1.19
 594  * @param array $urlParts URL parts, as output from wfParseUrl
 595  * @return string URL assembled from its component parts
 596  */
 597 function wfAssembleUrl( $urlParts ) {
 598         $result = '';
 599
 600         if ( isset( $urlParts['delimiter'] ) ) {
 601                 if ( isset( $urlParts['scheme'] ) ) {
 602                         $result .= $urlParts['scheme'];
 603                 }
 604
 605                 $result .= $urlParts['delimiter'];
 606         }
 607
 608         if ( isset( $urlParts['host'] ) ) {
 609                 if ( isset( $urlParts['user'] ) ) {
 610                         $result .= $urlParts['user'];
 611                         if ( isset( $urlParts['pass'] ) ) {
 612                                 $result .= ':' . $urlParts['pass'];
 613                         }
 614                         $result .= '@';
 615                 }
 616
 617                 $result .= $urlParts['host'];
 618
 619                 if ( isset( $urlParts['port'] ) ) {
 620                         $result .= ':' . $urlParts['port'];
 621                 }
 622         }
 623
 624         if ( isset( $urlParts['path'] ) ) {
 625                 $result .= $urlParts['path'];
 626         }
 627
 628         if ( isset( $urlParts['query'] ) ) {
 629                 $result .= '?' . $urlParts['query'];
 630         }
 631
 632         if ( isset( $urlParts['fragment'] ) ) {
 633                 $result .= '#' . $urlParts['fragment'];
 634         }
 635
 636         return $result;
 637 }
 638
 639 /**
 640  * Remove all dot-segments in the provided URL path.  For example,
 641  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 642  * RFC3986 section 5.2.4.
 643  *
 644  * @todo Need to integrate this into wfExpandUrl (see T34168)
 645  *
 646  * @param string $urlPath URL path, potentially containing dot-segments
 647  * @return string URL path with all dot-segments removed
 648  */
 649 function wfRemoveDotSegments( $urlPath ) {
 650         $output = '';
 651         $inputOffset = 0;
 652         $inputLength = strlen( $urlPath );
 653
 654         while ( $inputOffset < $inputLength ) {
 655                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 656                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 657                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 658                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 659                 $trimOutput = false;
 660
 661                 if ( $prefixLengthTwo == './' ) {
 662                         # Step A, remove leading "./"
 663                         $inputOffset += 2;
 664                 } elseif ( $prefixLengthThree == '../' ) {
 665                         # Step A, remove leading "../"
 666                         $inputOffset += 3;
 667                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 668                         # Step B, replace leading "/.$" with "/"
 669                         $inputOffset += 1;
 670                         $urlPath[$inputOffset] = '/';
 671                 } elseif ( $prefixLengthThree == '/./' ) {
 672                         # Step B, replace leading "/./" with "/"
 673                         $inputOffset += 2;
 674                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 675                         # Step C, replace leading "/..$" with "/" and
 676                         # remove last path component in output
 677                         $inputOffset += 2;
 678                         $urlPath[$inputOffset] = '/';
 679                         $trimOutput = true;
 680                 } elseif ( $prefixLengthFour == '/../' ) {
 681                         # Step C, replace leading "/../" with "/" and
 682                         # remove last path component in output
 683                         $inputOffset += 3;
 684                         $trimOutput = true;
 685                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 686                         # Step D, remove "^.$"
 687                         $inputOffset += 1;
 688                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 689                         # Step D, remove "^..$"
 690                         $inputOffset += 2;
 691                 } else {
 692                         # Step E, move leading path segment to output
 693                         if ( $prefixLengthOne == '/' ) {
 694                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 695                         } else {
 696                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 697                         }
 698                         if ( $slashPos === false ) {
 699                                 $output .= substr( $urlPath, $inputOffset );
 700                                 $inputOffset = $inputLength;
 701                         } else {
 702                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 703                                 $inputOffset += $slashPos - $inputOffset;
 704                         }
 705                 }
 706
 707                 if ( $trimOutput ) {
 708                         $slashPos = strrpos( $output, '/' );
 709                         if ( $slashPos === false ) {
 710                                 $output = '';
 711                         } else {
 712                                 $output = substr( $output, 0, $slashPos );
 713                         }
 714                 }
 715         }
 716
 717         return $output;
 718 }
 719
 720 /**
 721  * Returns a regular expression of url protocols
 722  *
 723  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 724  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 725  * @return string
 726  */
 727 function wfUrlProtocols( $includeProtocolRelative = true ) {
 728         global $wgUrlProtocols;
 729
 730         // Cache return values separately based on $includeProtocolRelative
 731         static $withProtRel = null, $withoutProtRel = null;
 732         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 733         if ( !is_null( $cachedValue ) ) {
 734                 return $cachedValue;
 735         }
 736
 737         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 738         // with LocalSettings files from 1.5
 739         if ( is_array( $wgUrlProtocols ) ) {
 740                 $protocols = [];
 741                 foreach ( $wgUrlProtocols as $protocol ) {
 742                         // Filter out '//' if !$includeProtocolRelative
 743                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 744                                 $protocols[] = preg_quote( $protocol, '/' );
 745                         }
 746                 }
 747
 748                 $retval = implode( '|', $protocols );
 749         } else {
 750                 // Ignore $includeProtocolRelative in this case
 751                 // This case exists for pre-1.6 compatibility, and we can safely assume
 752                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 753                 // URLs weren't supported until 1.18
 754                 $retval = $wgUrlProtocols;
 755         }
 756
 757         // Cache return value
 758         if ( $includeProtocolRelative ) {
 759                 $withProtRel = $retval;
 760         } else {
 761                 $withoutProtRel = $retval;
 762         }
 763         return $retval;
 764 }
 765
 766 /**
 767  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 768  * you need a regex that matches all URL protocols but does not match protocol-
 769  * relative URLs
 770  * @return string
 771  */
 772 function wfUrlProtocolsWithoutProtRel() {
 773         return wfUrlProtocols( false );
 774 }
 775
 776 /**
 777  * parse_url() work-alike, but non-broken.  Differences:
 778  *
 779  * 1) Does not raise warnings on bad URLs (just returns false).
 780  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 781  *    protocol-relative URLs) correctly.
 782  * 3) Adds a "delimiter" element to the array (see (2)).
 783  * 4) Verifies that the protocol is on the $wgUrlProtocols whitelist.
 784  * 5) Rejects some invalid URLs that parse_url doesn't, e.g. the empty string or URLs starting with
 785  *    a line feed character.
 786  *
 787  * @param string $url A URL to parse
 788  * @return string[]|bool Bits of the URL in an associative array, or false on failure.
 789  *   Possible fields:
 790  *   - scheme: URI scheme (protocol), e.g. 'http', 'mailto'. Lowercase, always present, but can
 791  *       be an empty string for protocol-relative URLs.
 792  *   - delimiter: either '://', ':' or '//'. Always present.
 793  *   - host: domain name / IP. Always present, but could be an empty string, e.g. for file: URLs.
 794  *   - user: user name, e.g. for HTTP Basic auth URLs such as http://user:pass@example.com/
 795  *       Missing when there is no username.
 796  *   - pass: password, same as above.
 797  *   - path: path including the leading /. Will be missing when empty (e.g. 'http://example.com')
 798  *   - query: query string (as a string; see wfCgiToArray() for parsing it), can be missing.
 799  *   - fragment: the part after #, can be missing.
 800  */
 801 function wfParseUrl( $url ) {
 802         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 803
 804         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 805         // bad that the easiest way to handle them is to just prepend 'http:' and
 806         // strip the protocol out later.
 807         $wasRelative = substr( $url, 0, 2 ) == '//';
 808         if ( $wasRelative ) {
 809                 $url = "http:$url";
 810         }
 811         Wikimedia\suppressWarnings();
 812         $bits = parse_url( $url );
 813         Wikimedia\restoreWarnings();
 814
 815         // T212067: PHP < 5.6.28, 7.0.0–7.0.12, and HHVM (all relevant versions) screw up parsing
 816         // the query part of pathless URLs
 817         if ( isset( $bits['host'] ) && strpos( $bits['host'], '?' ) !== false ) {
 818                 list( $host, $query ) = explode( '?', $bits['host'], 2 );
 819                 $bits['host'] = $host;
 820                 $bits['query'] = $query
 821                         . ( $bits['path'] ?? '' )
 822                         . ( isset( $bits['query'] ) ? '?' . $bits['query'] : '' );
 823                 unset( $bits['path'] );
 824         }
 825
 826         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 827         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 828         if ( !$bits || !isset( $bits['scheme'] ) ) {
 829                 return false;
 830         }
 831
 832         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 833         $bits['scheme'] = strtolower( $bits['scheme'] );
 834
 835         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 836         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 837                 $bits['delimiter'] = '://';
 838         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 839                 $bits['delimiter'] = ':';
 840                 // parse_url detects for news: and mailto: the host part of an url as path
 841                 // We have to correct this wrong detection
 842                 if ( isset( $bits['path'] ) ) {
 843                         $bits['host'] = $bits['path'];
 844                         $bits['path'] = '';
 845                 }
 846         } else {
 847                 return false;
 848         }
 849
 850         /* Provide an empty host for eg. file:/// urls (see T30627) */
 851         if ( !isset( $bits['host'] ) ) {
 852                 $bits['host'] = '';
 853
 854                 // See T47069
 855                 if ( isset( $bits['path'] ) ) {
 856                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 857                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 858                                 $bits['path'] = '/' . $bits['path'];
 859                         }
 860                 } else {
 861                         $bits['path'] = '';
 862                 }
 863         }
 864
 865         // If the URL was protocol-relative, fix scheme and delimiter
 866         if ( $wasRelative ) {
 867                 $bits['scheme'] = '';
 868                 $bits['delimiter'] = '//';
 869         }
 870         return $bits;
 871 }
 872
 873 /**
 874  * Take a URL, make sure it's expanded to fully qualified, and replace any
 875  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 876  * for more compact display and legibility for local audiences.
 877  *
 878  * @todo handle punycode domains too
 879  *
 880  * @param string $url
 881  * @return string
 882  */
 883 function wfExpandIRI( $url ) {
 884         return preg_replace_callback(
 885                 '/((?:%[89A-F][0-9A-F])+)/i',
 886                 'wfExpandIRI_callback',
 887                 wfExpandUrl( $url )
 888         );
 889 }
 890
 891 /**
 892  * Private callback for wfExpandIRI
 893  * @param array $matches
 894  * @return string
 895  */
 896 function wfExpandIRI_callback( $matches ) {
 897         return urldecode( $matches[1] );
 898 }
 899
 900 /**
 901  * Make URL indexes, appropriate for the el_index field of externallinks.
 902  *
 903  * @param string $url
 904  * @return array
 905  */
 906 function wfMakeUrlIndexes( $url ) {
 907         $bits = wfParseUrl( $url );
 908
 909         // Reverse the labels in the hostname, convert to lower case
 910         // For emails reverse domainpart only
 911         if ( $bits['scheme'] == 'mailto' ) {
 912                 $mailparts = explode( '@', $bits['host'], 2 );
 913                 if ( count( $mailparts ) === 2 ) {
 914                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 915                 } else {
 916                         // No domain specified, don't mangle it
 917                         $domainpart = '';
 918                 }
 919                 $reversedHost = $domainpart . '@' . $mailparts[0];
 920         } else {
 921                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 922         }
 923         // Add an extra dot to the end
 924         // Why? Is it in wrong place in mailto links?
 925         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 926                 $reversedHost .= '.';
 927         }
 928         // Reconstruct the pseudo-URL
 929         $prot = $bits['scheme'];
 930         $index = $prot . $bits['delimiter'] . $reversedHost;
 931         // Leave out user and password. Add the port, path, query and fragment
 932         if ( isset( $bits['port'] ) ) {
 933                 $index .= ':' . $bits['port'];
 934         }
 935         if ( isset( $bits['path'] ) ) {
 936                 $index .= $bits['path'];
 937         } else {
 938                 $index .= '/';
 939         }
 940         if ( isset( $bits['query'] ) ) {
 941                 $index .= '?' . $bits['query'];
 942         }
 943         if ( isset( $bits['fragment'] ) ) {
 944                 $index .= '#' . $bits['fragment'];
 945         }
 946
 947         if ( $prot == '' ) {
 948                 return [ "http:$index", "https:$index" ];
 949         } else {
 950                 return [ $index ];
 951         }
 952 }
 953
 954 /**
 955  * Check whether a given URL has a domain that occurs in a given set of domains
 956  * @param string $url
 957  * @param array $domains Array of domains (strings)
 958  * @return bool True if the host part of $url ends in one of the strings in $domains
 959  */
 960 function wfMatchesDomainList( $url, $domains ) {
 961         $bits = wfParseUrl( $url );
 962         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 963                 $host = '.' . $bits['host'];
 964                 foreach ( (array)$domains as $domain ) {
 965                         $domain = '.' . $domain;
 966                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 967                                 return true;
 968                         }
 969                 }
 970         }
 971         return false;
 972 }
 973
 974 /**
 975  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 976  * In normal operation this is a NOP.
 977  *
 978  * Controlling globals:
 979  * $wgDebugLogFile - points to the log file
 980  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 981  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 982  *
 983  * @since 1.25 support for additional context data
 984  *
 985  * @param string $text
 986  * @param string|bool $dest Destination of the message:
 987  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 988  *     - 'private': excluded from HTML output
 989  *   For backward compatibility, it can also take a boolean:
 990  *     - true: same as 'all'
 991  *     - false: same as 'private'
 992  * @param array $context Additional logging context data
 993  */
 994 function wfDebug( $text, $dest = 'all', array $context = [] ) {
 995         global $wgDebugRawPage, $wgDebugLogPrefix;
 996         global $wgDebugTimestamps;
 997
 998         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 999                 return;
1000         }
1001
1002         $text = trim( $text );
1003
1004         if ( $wgDebugTimestamps ) {
1005                 $context['seconds_elapsed'] = sprintf(
1006                         '%6.4f',
1007                         microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT']
1008                 );
1009                 $context['memory_used'] = sprintf(
1010                         '%5.1fM',
1011                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1012                 );
1013         }
1014
1015         if ( $wgDebugLogPrefix !== '' ) {
1016                 $context['prefix'] = $wgDebugLogPrefix;
1017         }
1018         $context['private'] = ( $dest === false || $dest === 'private' );
1019
1020         $logger = LoggerFactory::getInstance( 'wfDebug' );
1021         $logger->debug( $text, $context );
1022 }
1023
1024 /**
1025  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1026  * @return bool
1027  */
1028 function wfIsDebugRawPage() {
1029         static $cache;
1030         if ( $cache !== null ) {
1031                 return $cache;
1032         }
1033         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1034         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1035                 || (
1036                         isset( $_SERVER['SCRIPT_NAME'] )
1037                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1038                 )
1039         ) {
1040                 $cache = true;
1041         } else {
1042                 $cache = false;
1043         }
1044         return $cache;
1045 }
1046
1047 /**
1048  * Send a line giving PHP memory usage.
1049  *
1050  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1051  */
1052 function wfDebugMem( $exact = false ) {
1053         $mem = memory_get_usage();
1054         if ( !$exact ) {
1055                 $mem = floor( $mem / 1024 ) . ' KiB';
1056         } else {
1057                 $mem .= ' B';
1058         }
1059         wfDebug( "Memory usage: $mem\n" );
1060 }
1061
1062 /**
1063  * Send a line to a supplementary debug log file, if configured, or main debug
1064  * log if not.
1065  *
1066  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1067  * a string filename or an associative array mapping 'destination' to the
1068  * desired filename. The associative array may also contain a 'sample' key
1069  * with an integer value, specifying a sampling factor. Sampled log events
1070  * will be emitted with a 1 in N random chance.
1071  *
1072  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1073  * @since 1.25 support for additional context data
1074  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1075  *
1076  * @param string $logGroup
1077  * @param string $text
1078  * @param string|bool $dest Destination of the message:
1079  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1080  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1081  *       discarded otherwise
1082  *   For backward compatibility, it can also take a boolean:
1083  *     - true: same as 'all'
1084  *     - false: same as 'private'
1085  * @param array $context Additional logging context data
1086  */
1087 function wfDebugLog(
1088         $logGroup, $text, $dest = 'all', array $context = []
1089 ) {
1090         $text = trim( $text );
1091
1092         $logger = LoggerFactory::getInstance( $logGroup );
1093         $context['private'] = ( $dest === false || $dest === 'private' );
1094         $logger->info( $text, $context );
1095 }
1096
1097 /**
1098  * Log for database errors
1099  *
1100  * @since 1.25 support for additional context data
1101  *
1102  * @param string $text Database error message.
1103  * @param array $context Additional logging context data
1104  */
1105 function wfLogDBError( $text, array $context = [] ) {
1106         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1107         $logger->error( trim( $text ), $context );
1108 }
1109
1110 /**
1111  * Throws a warning that $function is deprecated
1112  *
1113  * @param string $function
1114  * @param string|bool $version Version of MediaWiki that the function
1115  *    was deprecated in (Added in 1.19).
1116  * @param string|bool $component Added in 1.19.
1117  * @param int $callerOffset How far up the call stack is the original
1118  *    caller. 2 = function that called the function that called
1119  *    wfDeprecated (Added in 1.20)
1120  *
1121  * @return null
1122  */
1123 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1124         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1125 }
1126
1127 /**
1128  * Send a warning either to the debug log or in a PHP error depending on
1129  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1130  *
1131  * @param string $msg Message to send
1132  * @param int $callerOffset Number of items to go back in the backtrace to
1133  *        find the correct caller (1 = function calling wfWarn, ...)
1134  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1135  *        only used when $wgDevelopmentWarnings is true
1136  */
1137 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1138         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1139 }
1140
1141 /**
1142  * Send a warning as a PHP error and the debug log. This is intended for logging
1143  * warnings in production. For logging development warnings, use WfWarn instead.
1144  *
1145  * @param string $msg Message to send
1146  * @param int $callerOffset Number of items to go back in the backtrace to
1147  *        find the correct caller (1 = function calling wfLogWarning, ...)
1148  * @param int $level PHP error level; defaults to E_USER_WARNING
1149  */
1150 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1151         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1152 }
1153
1154 /**
1155  * Log to a file without getting "file size exceeded" signals.
1156  *
1157  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1158  * send lines to the specified port, prefixed by the specified prefix and a space.
1159  * @since 1.25 support for additional context data
1160  *
1161  * @param string $text
1162  * @param string $file Filename
1163  * @param array $context Additional logging context data
1164  * @throws MWException
1165  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1166  */
1167 function wfErrorLog( $text, $file, array $context = [] ) {
1168         wfDeprecated( __METHOD__, '1.25' );
1169         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1170         $context['destination'] = $file;
1171         $logger->info( trim( $text ), $context );
1172 }
1173
1174 /**
1175  * @todo document
1176  * @todo Move logic to MediaWiki.php
1177  */
1178 function wfLogProfilingData() {
1179         global $wgDebugLogGroups, $wgDebugRawPage;
1180
1181         $context = RequestContext::getMain();
1182         $request = $context->getRequest();
1183
1184         $profiler = Profiler::instance();
1185         $profiler->setContext( $context );
1186         $profiler->logData();
1187
1188         // Send out any buffered statsd metrics as needed
1189         MediaWiki::emitBufferedStatsdData(
1190                 MediaWikiServices::getInstance()->getStatsdDataFactory(),
1191                 $context->getConfig()
1192         );
1193
1194         // Profiling must actually be enabled...
1195         if ( $profiler instanceof ProfilerStub ) {
1196                 return;
1197         }
1198
1199         if ( isset( $wgDebugLogGroups['profileoutput'] )
1200                 && $wgDebugLogGroups['profileoutput'] === false
1201         ) {
1202                 // Explicitly disabled
1203                 return;
1204         }
1205         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1206                 return;
1207         }
1208
1209         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1210         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1211                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1212         }
1213         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1214                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1215         }
1216         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1217                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1218         }
1219         if ( isset( $ctx['forwarded_for'] ) ||
1220                 isset( $ctx['client_ip'] ) ||
1221                 isset( $ctx['from'] ) ) {
1222                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1223         }
1224
1225         // Don't load $wgUser at this late stage just for statistics purposes
1226         // @todo FIXME: We can detect some anons even if it is not loaded.
1227         // See User::getId()
1228         $user = $context->getUser();
1229         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1230
1231         // Command line script uses a FauxRequest object which does not have
1232         // any knowledge about an URL and throw an exception instead.
1233         try {
1234                 $ctx['url'] = urldecode( $request->getRequestURL() );
1235         } catch ( Exception $ignored ) {
1236                 // no-op
1237         }
1238
1239         $ctx['output'] = $profiler->getOutput();
1240
1241         $log = LoggerFactory::getInstance( 'profileoutput' );
1242         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1243 }
1244
1245 /**
1246  * Increment a statistics counter
1247  *
1248  * @param string $key
1249  * @param int $count
1250  * @return void
1251  */
1252 function wfIncrStats( $key, $count = 1 ) {
1253         $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1254         $stats->updateCount( $key, $count );
1255 }
1256
1257 /**
1258  * Check whether the wiki is in read-only mode.
1259  *
1260  * @return bool
1261  */
1262 function wfReadOnly() {
1263         return MediaWikiServices::getInstance()->getReadOnlyMode()
1264                 ->isReadOnly();
1265 }
1266
1267 /**
1268  * Check if the site is in read-only mode and return the message if so
1269  *
1270  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1271  * for replica DB lag. This may result in DB connection being made.
1272  *
1273  * @return string|bool String when in read-only mode; false otherwise
1274  */
1275 function wfReadOnlyReason() {
1276         return MediaWikiServices::getInstance()->getReadOnlyMode()
1277                 ->getReason();
1278 }
1279
1280 /**
1281  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1282  *
1283  * @return string|bool String when in read-only mode; false otherwise
1284  * @since 1.27
1285  */
1286 function wfConfiguredReadOnlyReason() {
1287         return MediaWikiServices::getInstance()->getConfiguredReadOnlyMode()
1288                 ->getReason();
1289 }
1290
1291 /**
1292  * Return a Language object from $langcode
1293  *
1294  * @param Language|string|bool $langcode Either:
1295  *                  - a Language object
1296  *                  - code of the language to get the message for, if it is
1297  *                    a valid code create a language for that language, if
1298  *                    it is a string but not a valid code then make a basic
1299  *                    language object
1300  *                  - a boolean: if it's false then use the global object for
1301  *                    the current user's language (as a fallback for the old parameter
1302  *                    functionality), or if it is true then use global object
1303  *                    for the wiki's content language.
1304  * @return Language
1305  */
1306 function wfGetLangObj( $langcode = false ) {
1307         # Identify which language to get or create a language object for.
1308         # Using is_object here due to Stub objects.
1309         if ( is_object( $langcode ) ) {
1310                 # Great, we already have the object (hopefully)!
1311                 return $langcode;
1312         }
1313
1314         global $wgContLang, $wgLanguageCode;
1315         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1316                 # $langcode is the language code of the wikis content language object.
1317                 # or it is a boolean and value is true
1318                 return $wgContLang;
1319         }
1320
1321         global $wgLang;
1322         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1323                 # $langcode is the language code of user language object.
1324                 # or it was a boolean and value is false
1325                 return $wgLang;
1326         }
1327
1328         $validCodes = array_keys( Language::fetchLanguageNames() );
1329         if ( in_array( $langcode, $validCodes ) ) {
1330                 # $langcode corresponds to a valid language.
1331                 return Language::factory( $langcode );
1332         }
1333
1334         # $langcode is a string, but not a valid language code; use content language.
1335         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1336         return $wgContLang;
1337 }
1338
1339 /**
1340  * This is the function for getting translated interface messages.
1341  *
1342  * @see Message class for documentation how to use them.
1343  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1344  *
1345  * This function replaces all old wfMsg* functions.
1346  *
1347  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1348  * @param mixed $params,... Normal message parameters
1349  * @return Message
1350  *
1351  * @since 1.17
1352  *
1353  * @see Message::__construct
1354  */
1355 function wfMessage( $key /*...*/ ) {
1356         $message = new Message( $key );
1357
1358         // We call Message::params() to reduce code duplication
1359         $params = func_get_args();
1360         array_shift( $params );
1361         if ( $params ) {
1362                 call_user_func_array( [ $message, 'params' ], $params );
1363         }
1364
1365         return $message;
1366 }
1367
1368 /**
1369  * This function accepts multiple message keys and returns a message instance
1370  * for the first message which is non-empty. If all messages are empty then an
1371  * instance of the first message key is returned.
1372  *
1373  * @param string|string[] $keys,... Message keys
1374  * @return Message
1375  *
1376  * @since 1.18
1377  *
1378  * @see Message::newFallbackSequence
1379  */
1380 function wfMessageFallback( /*...*/ ) {
1381         $args = func_get_args();
1382         return call_user_func_array( 'Message::newFallbackSequence', $args );
1383 }
1384
1385 /**
1386  * Replace message parameter keys on the given formatted output.
1387  *
1388  * @param string $message
1389  * @param array $args
1390  * @return string
1391  * @private
1392  */
1393 function wfMsgReplaceArgs( $message, $args ) {
1394         # Fix windows line-endings
1395         # Some messages are split with explode("\n", $msg)
1396         $message = str_replace( "\r", '', $message );
1397
1398         // Replace arguments
1399         if ( is_array( $args ) && $args ) {
1400                 if ( is_array( $args[0] ) ) {
1401                         $args = array_values( $args[0] );
1402                 }
1403                 $replacementKeys = [];
1404                 foreach ( $args as $n => $param ) {
1405                         $replacementKeys['$' . ( $n + 1 )] = $param;
1406                 }
1407                 $message = strtr( $message, $replacementKeys );
1408         }
1409
1410         return $message;
1411 }
1412
1413 /**
1414  * Fetch server name for use in error reporting etc.
1415  * Use real server name if available, so we know which machine
1416  * in a server farm generated the current page.
1417  *
1418  * @return string
1419  */
1420 function wfHostname() {
1421         static $host;
1422         if ( is_null( $host ) ) {
1423                 # Hostname overriding
1424                 global $wgOverrideHostname;
1425                 if ( $wgOverrideHostname !== false ) {
1426                         # Set static and skip any detection
1427                         $host = $wgOverrideHostname;
1428                         return $host;
1429                 }
1430
1431                 if ( function_exists( 'posix_uname' ) ) {
1432                         // This function not present on Windows
1433                         $uname = posix_uname();
1434                 } else {
1435                         $uname = false;
1436                 }
1437                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1438                         $host = $uname['nodename'];
1439                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1440                         # Windows computer name
1441                         $host = getenv( 'COMPUTERNAME' );
1442                 } else {
1443                         # This may be a virtual server.
1444                         $host = $_SERVER['SERVER_NAME'];
1445                 }
1446         }
1447         return $host;
1448 }
1449
1450 /**
1451  * Returns a script tag that stores the amount of time it took MediaWiki to
1452  * handle the request in milliseconds as 'wgBackendResponseTime'.
1453  *
1454  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1455  * hostname of the server handling the request.
1456  *
1457  * @return string
1458  */
1459 function wfReportTime() {
1460         global $wgShowHostnames;
1461
1462         $elapsed = ( microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT'] );
1463         // seconds to milliseconds
1464         $responseTime = round( $elapsed * 1000 );
1465         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1466         if ( $wgShowHostnames ) {
1467                 $reportVars['wgHostname'] = wfHostname();
1468         }
1469         return Skin::makeVariablesScript( $reportVars );
1470 }
1471
1472 /**
1473  * Safety wrapper for debug_backtrace().
1474  *
1475  * Will return an empty array if debug_backtrace is disabled, otherwise
1476  * the output from debug_backtrace() (trimmed).
1477  *
1478  * @param int $limit This parameter can be used to limit the number of stack frames returned
1479  *
1480  * @return array Array of backtrace information
1481  */
1482 function wfDebugBacktrace( $limit = 0 ) {
1483         static $disabled = null;
1484
1485         if ( is_null( $disabled ) ) {
1486                 $disabled = !function_exists( 'debug_backtrace' );
1487                 if ( $disabled ) {
1488                         wfDebug( "debug_backtrace() is disabled\n" );
1489                 }
1490         }
1491         if ( $disabled ) {
1492                 return [];
1493         }
1494
1495         if ( $limit ) {
1496                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1497         } else {
1498                 return array_slice( debug_backtrace(), 1 );
1499         }
1500 }
1501
1502 /**
1503  * Get a debug backtrace as a string
1504  *
1505  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1506  *   Defaults to $wgCommandLineMode if unset.
1507  * @return string
1508  * @since 1.25 Supports $raw parameter.
1509  */
1510 function wfBacktrace( $raw = null ) {
1511         global $wgCommandLineMode;
1512
1513         if ( $raw === null ) {
1514                 $raw = $wgCommandLineMode;
1515         }
1516
1517         if ( $raw ) {
1518                 $frameFormat = "%s line %s calls %s()\n";
1519                 $traceFormat = "%s";
1520         } else {
1521                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1522                 $traceFormat = "<ul>\n%s</ul>\n";
1523         }
1524
1525         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1526                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1527                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1528                 $call = $frame['function'];
1529                 if ( !empty( $frame['class'] ) ) {
1530                         $call = $frame['class'] . $frame['type'] . $call;
1531                 }
1532                 return sprintf( $frameFormat, $file, $line, $call );
1533         }, wfDebugBacktrace() );
1534
1535         return sprintf( $traceFormat, implode( '', $frames ) );
1536 }
1537
1538 /**
1539  * Get the name of the function which called this function
1540  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1541  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1542  * wfGetCaller( 3 ) is the parent of that.
1543  *
1544  * @param int $level
1545  * @return string
1546  */
1547 function wfGetCaller( $level = 2 ) {
1548         $backtrace = wfDebugBacktrace( $level + 1 );
1549         if ( isset( $backtrace[$level] ) ) {
1550                 return wfFormatStackFrame( $backtrace[$level] );
1551         } else {
1552                 return 'unknown';
1553         }
1554 }
1555
1556 /**
1557  * Return a string consisting of callers in the stack. Useful sometimes
1558  * for profiling specific points.
1559  *
1560  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1561  * @return string
1562  */
1563 function wfGetAllCallers( $limit = 3 ) {
1564         $trace = array_reverse( wfDebugBacktrace() );
1565         if ( !$limit || $limit > count( $trace ) - 1 ) {
1566                 $limit = count( $trace ) - 1;
1567         }
1568         $trace = array_slice( $trace, -$limit - 1, $limit );
1569         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1570 }
1571
1572 /**
1573  * Return a string representation of frame
1574  *
1575  * @param array $frame
1576  * @return string
1577  */
1578 function wfFormatStackFrame( $frame ) {
1579         if ( !isset( $frame['function'] ) ) {
1580                 return 'NO_FUNCTION_GIVEN';
1581         }
1582         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1583                 $frame['class'] . $frame['type'] . $frame['function'] :
1584                 $frame['function'];
1585 }
1586
1587 /* Some generic result counters, pulled out of SearchEngine */
1588
1589 /**
1590  * @todo document
1591  *
1592  * @param int $offset
1593  * @param int $limit
1594  * @return string
1595  */
1596 function wfShowingResults( $offset, $limit ) {
1597         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1598 }
1599
1600 /**
1601  * Whether the client accept gzip encoding
1602  *
1603  * Uses the Accept-Encoding header to check if the client supports gzip encoding.
1604  * Use this when considering to send a gzip-encoded response to the client.
1605  *
1606  * @param bool $force Forces another check even if we already have a cached result.
1607  * @return bool
1608  */
1609 function wfClientAcceptsGzip( $force = false ) {
1610         static $result = null;
1611         if ( $result === null || $force ) {
1612                 $result = false;
1613                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1614                         # @todo FIXME: We may want to blacklist some broken browsers
1615                         $m = [];
1616                         if ( preg_match(
1617                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1618                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1619                                         $m
1620                                 )
1621                         ) {
1622                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1623                                         $result = false;
1624                                         return $result;
1625                                 }
1626                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1627                                 $result = true;
1628                         }
1629                 }
1630         }
1631         return $result;
1632 }
1633
1634 /**
1635  * Escapes the given text so that it may be output using addWikiText()
1636  * without any linking, formatting, etc. making its way through. This
1637  * is achieved by substituting certain characters with HTML entities.
1638  * As required by the callers, "<nowiki>" is not used.
1639  *
1640  * @param string $text Text to be escaped
1641  * @return string
1642  */
1643 function wfEscapeWikiText( $text ) {
1644         global $wgEnableMagicLinks;
1645         static $repl = null, $repl2 = null;
1646         if ( $repl === null || defined( 'MW_PARSER_TEST' ) || defined( 'MW_PHPUNIT_TEST' ) ) {
1647                 // Tests depend upon being able to change $wgEnableMagicLinks, so don't cache
1648                 // in those situations
1649                 $repl = [
1650                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1651                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1652                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1653                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1654                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1655                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1656                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1657                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1658                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1659                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1660                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1661                         '__' => '_&#95;', '://' => '&#58;//',
1662                 ];
1663
1664                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1665                 // We have to catch everything "\s" matches in PCRE
1666                 foreach ( $magicLinks as $magic ) {
1667                         $repl["$magic "] = "$magic&#32;";
1668                         $repl["$magic\t"] = "$magic&#9;";
1669                         $repl["$magic\r"] = "$magic&#13;";
1670                         $repl["$magic\n"] = "$magic&#10;";
1671                         $repl["$magic\f"] = "$magic&#12;";
1672                 }
1673
1674                 // And handle protocols that don't use "://"
1675                 global $wgUrlProtocols;
1676                 $repl2 = [];
1677                 foreach ( $wgUrlProtocols as $prot ) {
1678                         if ( substr( $prot, -1 ) === ':' ) {
1679                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1680                         }
1681                 }
1682                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1683         }
1684         $text = substr( strtr( "\n$text", $repl ), 1 );
1685         $text = preg_replace( $repl2, '$1&#58;', $text );
1686         return $text;
1687 }
1688
1689 /**
1690  * Sets dest to source and returns the original value of dest
1691  * If source is NULL, it just returns the value, it doesn't set the variable
1692  * If force is true, it will set the value even if source is NULL
1693  *
1694  * @param mixed &$dest
1695  * @param mixed $source
1696  * @param bool $force
1697  * @return mixed
1698  */
1699 function wfSetVar( &$dest, $source, $force = false ) {
1700         $temp = $dest;
1701         if ( !is_null( $source ) || $force ) {
1702                 $dest = $source;
1703         }
1704         return $temp;
1705 }
1706
1707 /**
1708  * As for wfSetVar except setting a bit
1709  *
1710  * @param int &$dest
1711  * @param int $bit
1712  * @param bool $state
1713  *
1714  * @return bool
1715  */
1716 function wfSetBit( &$dest, $bit, $state = true ) {
1717         $temp = (bool)( $dest & $bit );
1718         if ( !is_null( $state ) ) {
1719                 if ( $state ) {
1720                         $dest |= $bit;
1721                 } else {
1722                         $dest &= ~$bit;
1723                 }
1724         }
1725         return $temp;
1726 }
1727
1728 /**
1729  * A wrapper around the PHP function var_export().
1730  * Either print it or add it to the regular output ($wgOut).
1731  *
1732  * @param mixed $var A PHP variable to dump.
1733  */
1734 function wfVarDump( $var ) {
1735         global $wgOut;
1736         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1737         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1738                 print $s;
1739         } else {
1740                 $wgOut->addHTML( $s );
1741         }
1742 }
1743
1744 /**
1745  * Provide a simple HTTP error.
1746  *
1747  * @param int|string $code
1748  * @param string $label
1749  * @param string $desc
1750  */
1751 function wfHttpError( $code, $label, $desc ) {
1752         global $wgOut;
1753         HttpStatus::header( $code );
1754         if ( $wgOut ) {
1755                 $wgOut->disable();
1756                 $wgOut->sendCacheControl();
1757         }
1758
1759         MediaWiki\HeaderCallback::warnIfHeadersSent();
1760         header( 'Content-type: text/html; charset=utf-8' );
1761         print '<!DOCTYPE html>' .
1762                 '<html><head><title>' .
1763                 htmlspecialchars( $label ) .
1764                 '</title></head><body><h1>' .
1765                 htmlspecialchars( $label ) .
1766                 '</h1><p>' .
1767                 nl2br( htmlspecialchars( $desc ) ) .
1768                 "</p></body></html>\n";
1769 }
1770
1771 /**
1772  * Clear away any user-level output buffers, discarding contents.
1773  *
1774  * Suitable for 'starting afresh', for instance when streaming
1775  * relatively large amounts of data without buffering, or wanting to
1776  * output image files without ob_gzhandler's compression.
1777  *
1778  * The optional $resetGzipEncoding parameter controls suppression of
1779  * the Content-Encoding header sent by ob_gzhandler; by default it
1780  * is left. See comments for wfClearOutputBuffers() for why it would
1781  * be used.
1782  *
1783  * Note that some PHP configuration options may add output buffer
1784  * layers which cannot be removed; these are left in place.
1785  *
1786  * @param bool $resetGzipEncoding
1787  */
1788 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1789         if ( $resetGzipEncoding ) {
1790                 // Suppress Content-Encoding and Content-Length
1791                 // headers from OutputHandler::handle.
1792                 global $wgDisableOutputCompression;
1793                 $wgDisableOutputCompression = true;
1794         }
1795         while ( $status = ob_get_status() ) {
1796                 if ( isset( $status['flags'] ) ) {
1797                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1798                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1799                 } elseif ( isset( $status['del'] ) ) {
1800                         $deleteable = $status['del'];
1801                 } else {
1802                         // Guess that any PHP-internal setting can't be removed.
1803                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1804                 }
1805                 if ( !$deleteable ) {
1806                         // Give up, and hope the result doesn't break
1807                         // output behavior.
1808                         break;
1809                 }
1810                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1811                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1812                         break;
1813                 }
1814                 if ( !ob_end_clean() ) {
1815                         // Could not remove output buffer handler; abort now
1816                         // to avoid getting in some kind of infinite loop.
1817                         break;
1818                 }
1819                 if ( $resetGzipEncoding ) {
1820                         if ( $status['name'] == 'ob_gzhandler' ) {
1821                                 // Reset the 'Content-Encoding' field set by this handler
1822                                 // so we can start fresh.
1823                                 header_remove( 'Content-Encoding' );
1824                                 break;
1825                         }
1826                 }
1827         }
1828 }
1829
1830 /**
1831  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1832  *
1833  * Clear away output buffers, but keep the Content-Encoding header
1834  * produced by ob_gzhandler, if any.
1835  *
1836  * This should be used for HTTP 304 responses, where you need to
1837  * preserve the Content-Encoding header of the real result, but
1838  * also need to suppress the output of ob_gzhandler to keep to spec
1839  * and avoid breaking Firefox in rare cases where the headers and
1840  * body are broken over two packets.
1841  */
1842 function wfClearOutputBuffers() {
1843         wfResetOutputBuffers( false );
1844 }
1845
1846 /**
1847  * Converts an Accept-* header into an array mapping string values to quality
1848  * factors
1849  *
1850  * @param string $accept
1851  * @param string $def Default
1852  * @return float[] Associative array of string => float pairs
1853  */
1854 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1855         # No arg means accept anything (per HTTP spec)
1856         if ( !$accept ) {
1857                 return [ $def => 1.0 ];
1858         }
1859
1860         $prefs = [];
1861
1862         $parts = explode( ',', $accept );
1863
1864         foreach ( $parts as $part ) {
1865                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1866                 $values = explode( ';', trim( $part ) );
1867                 $match = [];
1868                 if ( count( $values ) == 1 ) {
1869                         $prefs[$values[0]] = 1.0;
1870                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1871                         $prefs[$values[0]] = floatval( $match[1] );
1872                 }
1873         }
1874
1875         return $prefs;
1876 }
1877
1878 /**
1879  * Checks if a given MIME type matches any of the keys in the given
1880  * array. Basic wildcards are accepted in the array keys.
1881  *
1882  * Returns the matching MIME type (or wildcard) if a match, otherwise
1883  * NULL if no match.
1884  *
1885  * @param string $type
1886  * @param array $avail
1887  * @return string
1888  * @private
1889  */
1890 function mimeTypeMatch( $type, $avail ) {
1891         if ( array_key_exists( $type, $avail ) ) {
1892                 return $type;
1893         } else {
1894                 $mainType = explode( '/', $type )[0];
1895                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1896                         return "$mainType/*";
1897                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1898                         return '*/*';
1899                 } else {
1900                         return null;
1901                 }
1902         }
1903 }
1904
1905 /**
1906  * Returns the 'best' match between a client's requested internet media types
1907  * and the server's list of available types. Each list should be an associative
1908  * array of type to preference (preference is a float between 0.0 and 1.0).
1909  * Wildcards in the types are acceptable.
1910  *
1911  * @param array $cprefs Client's acceptable type list
1912  * @param array $sprefs Server's offered types
1913  * @return string
1914  *
1915  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1916  * XXX: generalize to negotiate other stuff
1917  */
1918 function wfNegotiateType( $cprefs, $sprefs ) {
1919         $combine = [];
1920
1921         foreach ( array_keys( $sprefs ) as $type ) {
1922                 $subType = explode( '/', $type )[1];
1923                 if ( $subType != '*' ) {
1924                         $ckey = mimeTypeMatch( $type, $cprefs );
1925                         if ( $ckey ) {
1926                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1927                         }
1928                 }
1929         }
1930
1931         foreach ( array_keys( $cprefs ) as $type ) {
1932                 $subType = explode( '/', $type )[1];
1933                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1934                         $skey = mimeTypeMatch( $type, $sprefs );
1935                         if ( $skey ) {
1936                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1937                         }
1938                 }
1939         }
1940
1941         $bestq = 0;
1942         $besttype = null;
1943
1944         foreach ( array_keys( $combine ) as $type ) {
1945                 if ( $combine[$type] > $bestq ) {
1946                         $besttype = $type;
1947                         $bestq = $combine[$type];
1948                 }
1949         }
1950
1951         return $besttype;
1952 }
1953
1954 /**
1955  * Reference-counted warning suppression
1956  *
1957  * @deprecated since 1.26, use Wikimedia\suppressWarnings() directly
1958  * @param bool $end
1959  */
1960 function wfSuppressWarnings( $end = false ) {
1961         Wikimedia\suppressWarnings( $end );
1962 }
1963
1964 /**
1965  * @deprecated since 1.26, use Wikimedia\restoreWarnings() directly
1966  * Restore error level to previous value
1967  */
1968 function wfRestoreWarnings() {
1969         Wikimedia\restoreWarnings();
1970 }
1971
1972 /**
1973  * Get a timestamp string in one of various formats
1974  *
1975  * @param mixed $outputtype A timestamp in one of the supported formats, the
1976  *   function will autodetect which format is supplied and act accordingly.
1977  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
1978  * @return string|bool String / false The same date in the format specified in $outputtype or false
1979  */
1980 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
1981         $ret = MWTimestamp::convert( $outputtype, $ts );
1982         if ( $ret === false ) {
1983                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
1984         }
1985         return $ret;
1986 }
1987
1988 /**
1989  * Return a formatted timestamp, or null if input is null.
1990  * For dealing with nullable timestamp columns in the database.
1991  *
1992  * @param int $outputtype
1993  * @param string $ts
1994  * @return string
1995  */
1996 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
1997         if ( is_null( $ts ) ) {
1998                 return null;
1999         } else {
2000                 return wfTimestamp( $outputtype, $ts );
2001         }
2002 }
2003
2004 /**
2005  * Convenience function; returns MediaWiki timestamp for the present time.
2006  *
2007  * @return string
2008  */
2009 function wfTimestampNow() {
2010         # return NOW
2011         return MWTimestamp::now( TS_MW );
2012 }
2013
2014 /**
2015  * Check if the operating system is Windows
2016  *
2017  * @return bool True if it's Windows, false otherwise.
2018  */
2019 function wfIsWindows() {
2020         static $isWindows = null;
2021         if ( $isWindows === null ) {
2022                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2023         }
2024         return $isWindows;
2025 }
2026
2027 /**
2028  * Check if we are running under HHVM
2029  *
2030  * @return bool
2031  */
2032 function wfIsHHVM() {
2033         return defined( 'HHVM_VERSION' );
2034 }
2035
2036 /**
2037  * Check if we are running from the commandline
2038  *
2039  * @since 1.31
2040  * @return bool
2041  */
2042 function wfIsCLI() {
2043         return PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg';
2044 }
2045
2046 /**
2047  * Tries to get the system directory for temporary files. First
2048  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2049  * environment variables are then checked in sequence, then
2050  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2051  *
2052  * NOTE: When possible, use instead the tmpfile() function to create
2053  * temporary files to avoid race conditions on file creation, etc.
2054  *
2055  * @return string
2056  */
2057 function wfTempDir() {
2058         global $wgTmpDirectory;
2059
2060         if ( $wgTmpDirectory !== false ) {
2061                 return $wgTmpDirectory;
2062         }
2063
2064         return TempFSFile::getUsableTempDirectory();
2065 }
2066
2067 /**
2068  * Make directory, and make all parent directories if they don't exist
2069  *
2070  * @param string $dir Full path to directory to create
2071  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2072  * @param string $caller Optional caller param for debugging.
2073  * @throws MWException
2074  * @return bool
2075  */
2076 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2077         global $wgDirectoryMode;
2078
2079         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2080                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2081         }
2082
2083         if ( !is_null( $caller ) ) {
2084                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2085         }
2086
2087         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2088                 return true;
2089         }
2090
2091         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
2092
2093         if ( is_null( $mode ) ) {
2094                 $mode = $wgDirectoryMode;
2095         }
2096
2097         // Turn off the normal warning, we're doing our own below
2098         Wikimedia\suppressWarnings();
2099         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2100         Wikimedia\restoreWarnings();
2101
2102         if ( !$ok ) {
2103                 // directory may have been created on another request since we last checked
2104                 if ( is_dir( $dir ) ) {
2105                         return true;
2106                 }
2107
2108                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2109                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2110         }
2111         return $ok;
2112 }
2113
2114 /**
2115  * Remove a directory and all its content.
2116  * Does not hide error.
2117  * @param string $dir
2118  */
2119 function wfRecursiveRemoveDir( $dir ) {
2120         wfDebug( __FUNCTION__ . "( $dir )\n" );
2121         // taken from https://secure.php.net/manual/en/function.rmdir.php#98622
2122         if ( is_dir( $dir ) ) {
2123                 $objects = scandir( $dir );
2124                 foreach ( $objects as $object ) {
2125                         if ( $object != "." && $object != ".." ) {
2126                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2127                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2128                                 } else {
2129                                         unlink( $dir . '/' . $object );
2130                                 }
2131                         }
2132                 }
2133                 reset( $objects );
2134                 rmdir( $dir );
2135         }
2136 }
2137
2138 /**
2139  * @param int $nr The number to format
2140  * @param int $acc The number of digits after the decimal point, default 2
2141  * @param bool $round Whether or not to round the value, default true
2142  * @return string
2143  */
2144 function wfPercent( $nr, $acc = 2, $round = true ) {
2145         $ret = sprintf( "%.${acc}f", $nr );
2146         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2147 }
2148
2149 /**
2150  * Safety wrapper around ini_get() for boolean settings.
2151  * The values returned from ini_get() are pre-normalized for settings
2152  * set via php.ini or php_flag/php_admin_flag... but *not*
2153  * for those set via php_value/php_admin_value.
2154  *
2155  * It's fairly common for people to use php_value instead of php_flag,
2156  * which can leave you with an 'off' setting giving a false positive
2157  * for code that just takes the ini_get() return value as a boolean.
2158  *
2159  * To make things extra interesting, setting via php_value accepts
2160  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2161  * Unrecognized values go false... again opposite PHP's own coercion
2162  * from string to bool.
2163  *
2164  * Luckily, 'properly' set settings will always come back as '0' or '1',
2165  * so we only have to worry about them and the 'improper' settings.
2166  *
2167  * I frickin' hate PHP... :P
2168  *
2169  * @param string $setting
2170  * @return bool
2171  */
2172 function wfIniGetBool( $setting ) {
2173         return wfStringToBool( ini_get( $setting ) );
2174 }
2175
2176 /**
2177  * Convert string value to boolean, when the following are interpreted as true:
2178  * - on
2179  * - true
2180  * - yes
2181  * - Any number, except 0
2182  * All other strings are interpreted as false.
2183  *
2184  * @param string $val
2185  * @return bool
2186  * @since 1.31
2187  */
2188 function wfStringToBool( $val ) {
2189         $val = strtolower( $val );
2190         // 'on' and 'true' can't have whitespace around them, but '1' can.
2191         return $val == 'on'
2192                 || $val == 'true'
2193                 || $val == 'yes'
2194                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2195 }
2196
2197 /**
2198  * Version of escapeshellarg() that works better on Windows.
2199  *
2200  * Originally, this fixed the incorrect use of single quotes on Windows
2201  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2202  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2203  *
2204  * @param string $args,... strings to escape and glue together,
2205  *  or a single array of strings parameter
2206  * @return string
2207  * @deprecated since 1.30 use MediaWiki\Shell::escape()
2208  */
2209 function wfEscapeShellArg( /*...*/ ) {
2210         $args = func_get_args();
2211
2212         return call_user_func_array( Shell::class . '::escape', $args );
2213 }
2214
2215 /**
2216  * Check if wfShellExec() is effectively disabled via php.ini config
2217  *
2218  * @return bool|string False or 'disabled'
2219  * @since 1.22
2220  * @deprecated since 1.30 use MediaWiki\Shell::isDisabled()
2221  */
2222 function wfShellExecDisabled() {
2223         wfDeprecated( __FUNCTION__, '1.30' );
2224         return Shell::isDisabled() ? 'disabled' : false;
2225 }
2226
2227 /**
2228  * Execute a shell command, with time and memory limits mirrored from the PHP
2229  * configuration if supported.
2230  *
2231  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2232  *   or an array of unescaped arguments, in which case each value will be escaped
2233  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2234  * @param null|mixed &$retval Optional, will receive the program's exit code.
2235  *   (non-zero is usually failure). If there is an error from
2236  *   read, select, or proc_open(), this will be set to -1.
2237  * @param array $environ Optional environment variables which should be
2238  *   added to the executed command environment.
2239  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2240  *   this overwrites the global wgMaxShell* limits.
2241  * @param array $options Array of options:
2242  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2243  *     including errors from limit.sh
2244  *   - profileMethod: By default this function will profile based on the calling
2245  *     method. Set this to a string for an alternative method to profile from
2246  *
2247  * @return string Collected stdout as a string
2248  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2249  */
2250 function wfShellExec( $cmd, &$retval = null, $environ = [],
2251         $limits = [], $options = []
2252 ) {
2253         if ( Shell::isDisabled() ) {
2254                 $retval = 1;
2255                 // Backwards compatibility be upon us...
2256                 return 'Unable to run external programs, proc_open() is disabled.';
2257         }
2258
2259         if ( is_array( $cmd ) ) {
2260                 $cmd = Shell::escape( $cmd );
2261         }
2262
2263         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2264         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2265
2266         try {
2267                 $result = Shell::command( [] )
2268                         ->unsafeParams( (array)$cmd )
2269                         ->environment( $environ )
2270                         ->limits( $limits )
2271                         ->includeStderr( $includeStderr )
2272                         ->profileMethod( $profileMethod )
2273                         // For b/c
2274                         ->restrict( Shell::RESTRICT_NONE )
2275                         ->execute();
2276         } catch ( ProcOpenError $ex ) {
2277                 $retval = -1;
2278                 return '';
2279         }
2280
2281         $retval = $result->getExitCode();
2282
2283         return $result->getStdout();
2284 }
2285
2286 /**
2287  * Execute a shell command, returning both stdout and stderr. Convenience
2288  * function, as all the arguments to wfShellExec can become unwieldy.
2289  *
2290  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2291  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2292  *   or an array of unescaped arguments, in which case each value will be escaped
2293  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2294  * @param null|mixed &$retval Optional, will receive the program's exit code.
2295  *   (non-zero is usually failure)
2296  * @param array $environ Optional environment variables which should be
2297  *   added to the executed command environment.
2298  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2299  *   this overwrites the global wgMaxShell* limits.
2300  * @return string Collected stdout and stderr as a string
2301  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2302  */
2303 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2304         return wfShellExec( $cmd, $retval, $environ, $limits,
2305                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2306 }
2307
2308 /**
2309  * Formerly set the locale for locale-sensitive operations
2310  *
2311  * This is now done in Setup.php.
2312  *
2313  * @deprecated since 1.30, no longer needed
2314  * @see $wgShellLocale
2315  */
2316 function wfInitShellLocale() {
2317         wfDeprecated( __FUNCTION__, '1.30' );
2318 }
2319
2320 /**
2321  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2322  * Note that $parameters should be a flat array and an option with an argument
2323  * should consist of two consecutive items in the array (do not use "--option value").
2324  *
2325  * @deprecated since 1.31, use Shell::makeScriptCommand()
2326  *
2327  * @param string $script MediaWiki cli script path
2328  * @param array $parameters Arguments and options to the script
2329  * @param array $options Associative array of options:
2330  *     'php': The path to the php executable
2331  *     'wrapper': Path to a PHP wrapper to handle the maintenance script
2332  * @return string
2333  */
2334 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2335         global $wgPhpCli;
2336         // Give site config file a chance to run the script in a wrapper.
2337         // The caller may likely want to call wfBasename() on $script.
2338         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2339         $cmd = isset( $options['php'] ) ? [ $options['php'] ] : [ $wgPhpCli ];
2340         if ( isset( $options['wrapper'] ) ) {
2341                 $cmd[] = $options['wrapper'];
2342         }
2343         $cmd[] = $script;
2344         // Escape each parameter for shell
2345         return Shell::escape( array_merge( $cmd, $parameters ) );
2346 }
2347
2348 /**
2349  * wfMerge attempts to merge differences between three texts.
2350  * Returns true for a clean merge and false for failure or a conflict.
2351  *
2352  * @param string $old
2353  * @param string $mine
2354  * @param string $yours
2355  * @param string &$result
2356  * @param string &$mergeAttemptResult
2357  * @return bool
2358  */
2359 function wfMerge( $old, $mine, $yours, &$result, &$mergeAttemptResult = null ) {
2360         global $wgDiff3;
2361
2362         # This check may also protect against code injection in
2363         # case of broken installations.
2364         Wikimedia\suppressWarnings();
2365         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2366         Wikimedia\restoreWarnings();
2367
2368         if ( !$haveDiff3 ) {
2369                 wfDebug( "diff3 not found\n" );
2370                 return false;
2371         }
2372
2373         # Make temporary files
2374         $td = wfTempDir();
2375         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2376         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2377         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2378
2379         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2380         #       a newline character. To avoid this, we normalize the trailing whitespace before
2381         #       creating the diff.
2382
2383         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2384         fclose( $oldtextFile );
2385         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2386         fclose( $mytextFile );
2387         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2388         fclose( $yourtextFile );
2389
2390         # Check for a conflict
2391         $cmd = Shell::escape( $wgDiff3, '-a', '--overlap-only', $mytextName,
2392                 $oldtextName, $yourtextName );
2393         $handle = popen( $cmd, 'r' );
2394
2395         $mergeAttemptResult = '';
2396         do {
2397                 $data = fread( $handle, 8192 );
2398                 if ( strlen( $data ) == 0 ) {
2399                         break;
2400                 }
2401                 $mergeAttemptResult .= $data;
2402         } while ( true );
2403         pclose( $handle );
2404
2405         $conflict = $mergeAttemptResult !== '';
2406
2407         # Merge differences
2408         $cmd = Shell::escape( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2409                 $oldtextName, $yourtextName );
2410         $handle = popen( $cmd, 'r' );
2411         $result = '';
2412         do {
2413                 $data = fread( $handle, 8192 );
2414                 if ( strlen( $data ) == 0 ) {
2415                         break;
2416                 }
2417                 $result .= $data;
2418         } while ( true );
2419         pclose( $handle );
2420         unlink( $mytextName );
2421         unlink( $oldtextName );
2422         unlink( $yourtextName );
2423
2424         if ( $result === '' && $old !== '' && !$conflict ) {
2425                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2426                 $conflict = true;
2427         }
2428         return !$conflict;
2429 }
2430
2431 /**
2432  * Returns unified plain-text diff of two texts.
2433  * "Useful" for machine processing of diffs.
2434  *
2435  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2436  *
2437  * @param string $before The text before the changes.
2438  * @param string $after The text after the changes.
2439  * @param string $params Command-line options for the diff command.
2440  * @return string Unified diff of $before and $after
2441  */
2442 function wfDiff( $before, $after, $params = '-u' ) {
2443         if ( $before == $after ) {
2444                 return '';
2445         }
2446
2447         global $wgDiff;
2448         Wikimedia\suppressWarnings();
2449         $haveDiff = $wgDiff && file_exists( $wgDiff );
2450         Wikimedia\restoreWarnings();
2451
2452         # This check may also protect against code injection in
2453         # case of broken installations.
2454         if ( !$haveDiff ) {
2455                 wfDebug( "diff executable not found\n" );
2456                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2457                 $format = new UnifiedDiffFormatter();
2458                 return $format->format( $diffs );
2459         }
2460
2461         # Make temporary files
2462         $td = wfTempDir();
2463         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2464         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2465
2466         fwrite( $oldtextFile, $before );
2467         fclose( $oldtextFile );
2468         fwrite( $newtextFile, $after );
2469         fclose( $newtextFile );
2470
2471         // Get the diff of the two files
2472         $cmd = "$wgDiff " . $params . ' ' . Shell::escape( $oldtextName, $newtextName );
2473
2474         $h = popen( $cmd, 'r' );
2475         if ( !$h ) {
2476                 unlink( $oldtextName );
2477                 unlink( $newtextName );
2478                 throw new Exception( __METHOD__ . '(): popen() failed' );
2479         }
2480
2481         $diff = '';
2482
2483         do {
2484                 $data = fread( $h, 8192 );
2485                 if ( strlen( $data ) == 0 ) {
2486                         break;
2487                 }
2488                 $diff .= $data;
2489         } while ( true );
2490
2491         // Clean up
2492         pclose( $h );
2493         unlink( $oldtextName );
2494         unlink( $newtextName );
2495
2496         // Kill the --- and +++ lines. They're not useful.
2497         $diff_lines = explode( "\n", $diff );
2498         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2499                 unset( $diff_lines[0] );
2500         }
2501         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2502                 unset( $diff_lines[1] );
2503         }
2504
2505         $diff = implode( "\n", $diff_lines );
2506
2507         return $diff;
2508 }
2509
2510 /**
2511  * This function works like "use VERSION" in Perl, the program will die with a
2512  * backtrace if the current version of PHP is less than the version provided
2513  *
2514  * This is useful for extensions which due to their nature are not kept in sync
2515  * with releases, and might depend on other versions of PHP than the main code
2516  *
2517  * Note: PHP might die due to parsing errors in some cases before it ever
2518  *       manages to call this function, such is life
2519  *
2520  * @see perldoc -f use
2521  *
2522  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2523  *
2524  * @deprecated since 1.30
2525  *
2526  * @throws MWException
2527  */
2528 function wfUsePHP( $req_ver ) {
2529         wfDeprecated( __FUNCTION__, '1.30' );
2530         $php_ver = PHP_VERSION;
2531
2532         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2533                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2534         }
2535 }
2536
2537 /**
2538  * This function works like "use VERSION" in Perl except it checks the version
2539  * of MediaWiki, the program will die with a backtrace if the current version
2540  * of MediaWiki is less than the version provided.
2541  *
2542  * This is useful for extensions which due to their nature are not kept in sync
2543  * with releases
2544  *
2545  * Note: Due to the behavior of PHP's version_compare() which is used in this
2546  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2547  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2548  * targeted version number. For example if you wanted to allow any variation
2549  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2550  * not result in the same comparison due to the internal logic of
2551  * version_compare().
2552  *
2553  * @see perldoc -f use
2554  *
2555  * @deprecated since 1.26, use the "requires" property of extension.json
2556  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2557  * @throws MWException
2558  */
2559 function wfUseMW( $req_ver ) {
2560         global $wgVersion;
2561
2562         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2563                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2564         }
2565 }
2566
2567 /**
2568  * Return the final portion of a pathname.
2569  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2570  * https://bugs.php.net/bug.php?id=33898
2571  *
2572  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2573  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2574  *
2575  * @param string $path
2576  * @param string $suffix String to remove if present
2577  * @return string
2578  */
2579 function wfBaseName( $path, $suffix = '' ) {
2580         if ( $suffix == '' ) {
2581                 $encSuffix = '';
2582         } else {
2583                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2584         }
2585
2586         $matches = [];
2587         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2588                 return $matches[1];
2589         } else {
2590                 return '';
2591         }
2592 }
2593
2594 /**
2595  * Generate a relative path name to the given file.
2596  * May explode on non-matching case-insensitive paths,
2597  * funky symlinks, etc.
2598  *
2599  * @param string $path Absolute destination path including target filename
2600  * @param string $from Absolute source path, directory only
2601  * @return string
2602  */
2603 function wfRelativePath( $path, $from ) {
2604         // Normalize mixed input on Windows...
2605         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2606         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2607
2608         // Trim trailing slashes -- fix for drive root
2609         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2610         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2611
2612         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2613         $against = explode( DIRECTORY_SEPARATOR, $from );
2614
2615         if ( $pieces[0] !== $against[0] ) {
2616                 // Non-matching Windows drive letters?
2617                 // Return a full path.
2618                 return $path;
2619         }
2620
2621         // Trim off common prefix
2622         while ( count( $pieces ) && count( $against )
2623                 && $pieces[0] == $against[0] ) {
2624                 array_shift( $pieces );
2625                 array_shift( $against );
2626         }
2627
2628         // relative dots to bump us to the parent
2629         while ( count( $against ) ) {
2630                 array_unshift( $pieces, '..' );
2631                 array_shift( $against );
2632         }
2633
2634         array_push( $pieces, wfBaseName( $path ) );
2635
2636         return implode( DIRECTORY_SEPARATOR, $pieces );
2637 }
2638
2639 /**
2640  * Reset the session id
2641  *
2642  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2643  * @since 1.22
2644  */
2645 function wfResetSessionID() {
2646         wfDeprecated( __FUNCTION__, '1.27' );
2647         $session = SessionManager::getGlobalSession();
2648         $delay = $session->delaySave();
2649
2650         $session->resetId();
2651
2652         // Make sure a session is started, since that's what the old
2653         // wfResetSessionID() did.
2654         if ( session_id() !== $session->getId() ) {
2655                 wfSetupSession( $session->getId() );
2656         }
2657
2658         ScopedCallback::consume( $delay );
2659 }
2660
2661 /**
2662  * Initialise php session
2663  *
2664  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2665  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2666  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2667  *  here), then calling $session->persist().
2668  * @param bool|string $sessionId
2669  */
2670 function wfSetupSession( $sessionId = false ) {
2671         wfDeprecated( __FUNCTION__, '1.27' );
2672
2673         if ( $sessionId ) {
2674                 session_id( $sessionId );
2675         }
2676
2677         $session = SessionManager::getGlobalSession();
2678         $session->persist();
2679
2680         if ( session_id() !== $session->getId() ) {
2681                 session_id( $session->getId() );
2682         }
2683         Wikimedia\quietCall( 'session_start' );
2684 }
2685
2686 /**
2687  * Get an object from the precompiled serialized directory
2688  *
2689  * @param string $name
2690  * @return mixed The variable on success, false on failure
2691  */
2692 function wfGetPrecompiledData( $name ) {
2693         global $IP;
2694
2695         $file = "$IP/serialized/$name";
2696         if ( file_exists( $file ) ) {
2697                 $blob = file_get_contents( $file );
2698                 if ( $blob ) {
2699                         return unserialize( $blob );
2700                 }
2701         }
2702         return false;
2703 }
2704
2705 /**
2706  * Make a cache key for the local wiki.
2707  *
2708  * @deprecated since 1.30 Call makeKey on a BagOStuff instance
2709  * @param string $args,...
2710  * @return string
2711  */
2712 function wfMemcKey( /*...*/ ) {
2713         return call_user_func_array(
2714                 [ ObjectCache::getLocalClusterInstance(), 'makeKey' ],
2715                 func_get_args()
2716         );
2717 }
2718
2719 /**
2720  * Make a cache key for a foreign DB.
2721  *
2722  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2723  *
2724  * @param string $db
2725  * @param string $prefix
2726  * @param string $args,...
2727  * @return string
2728  */
2729 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
2730         $args = array_slice( func_get_args(), 2 );
2731         $keyspace = $prefix ? "$db-$prefix" : $db;
2732         return call_user_func_array(
2733                 [ ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ],
2734                 [ $keyspace, $args ]
2735         );
2736 }
2737
2738 /**
2739  * Make a cache key with database-agnostic prefix.
2740  *
2741  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
2742  * instead. Must have a prefix as otherwise keys that use a database name
2743  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
2744  *
2745  * @deprecated since 1.30 Call makeGlobalKey on a BagOStuff instance
2746  * @since 1.26
2747  * @param string $args,...
2748  * @return string
2749  */
2750 function wfGlobalCacheKey( /*...*/ ) {
2751         return call_user_func_array(
2752                 [ ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ],
2753                 func_get_args()
2754         );
2755 }
2756
2757 /**
2758  * Get an ASCII string identifying this wiki
2759  * This is used as a prefix in memcached keys
2760  *
2761  * @return string
2762  */
2763 function wfWikiID() {
2764         global $wgDBprefix, $wgDBname;
2765         if ( $wgDBprefix ) {
2766                 return "$wgDBname-$wgDBprefix";
2767         } else {
2768                 return $wgDBname;
2769         }
2770 }
2771
2772 /**
2773  * Split a wiki ID into DB name and table prefix
2774  *
2775  * @param string $wiki
2776  *
2777  * @return array
2778  */
2779 function wfSplitWikiID( $wiki ) {
2780         $bits = explode( '-', $wiki, 2 );
2781         if ( count( $bits ) < 2 ) {
2782                 $bits[] = '';
2783         }
2784         return $bits;
2785 }
2786
2787 /**
2788  * Get a Database object.
2789  *
2790  * @param int $db Index of the connection to get. May be DB_MASTER for the
2791  *            master (for write queries), DB_REPLICA for potentially lagged read
2792  *            queries, or an integer >= 0 for a particular server.
2793  *
2794  * @param string|string[] $groups Query groups. An array of group names that this query
2795  *                belongs to. May contain a single string if the query is only
2796  *                in one group.
2797  *
2798  * @param string|bool $wiki The wiki ID, or false for the current wiki
2799  *
2800  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
2801  * will always return the same object, unless the underlying connection or load
2802  * balancer is manually destroyed.
2803  *
2804  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
2805  * updater to ensure that a proper database is being updated.
2806  *
2807  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
2808  *       on an injected instance of LoadBalancer.
2809  *
2810  * @return \Wikimedia\Rdbms\Database
2811  */
2812 function wfGetDB( $db, $groups = [], $wiki = false ) {
2813         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
2814 }
2815
2816 /**
2817  * Get a load balancer object.
2818  *
2819  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancer()
2820  *              or MediaWikiServices::getDBLoadBalancerFactory() instead.
2821  *
2822  * @param string|bool $wiki Wiki ID, or false for the current wiki
2823  * @return \Wikimedia\Rdbms\LoadBalancer
2824  */
2825 function wfGetLB( $wiki = false ) {
2826         if ( $wiki === false ) {
2827                 return MediaWikiServices::getInstance()->getDBLoadBalancer();
2828         } else {
2829                 $factory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2830                 return $factory->getMainLB( $wiki );
2831         }
2832 }
2833
2834 /**
2835  * Get the load balancer factory object
2836  *
2837  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancerFactory() instead.
2838  *
2839  * @return \Wikimedia\Rdbms\LBFactory
2840  */
2841 function wfGetLBFactory() {
2842         return MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2843 }
2844
2845 /**
2846  * Find a file.
2847  * Shortcut for RepoGroup::singleton()->findFile()
2848  *
2849  * @param string|Title $title String or Title object
2850  * @param array $options Associative array of options (see RepoGroup::findFile)
2851  * @return File|bool File, or false if the file does not exist
2852  */
2853 function wfFindFile( $title, $options = [] ) {
2854         return RepoGroup::singleton()->findFile( $title, $options );
2855 }
2856
2857 /**
2858  * Get an object referring to a locally registered file.
2859  * Returns a valid placeholder object if the file does not exist.
2860  *
2861  * @param Title|string $title
2862  * @return LocalFile|null A File, or null if passed an invalid Title
2863  */
2864 function wfLocalFile( $title ) {
2865         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
2866 }
2867
2868 /**
2869  * Should low-performance queries be disabled?
2870  *
2871  * @return bool
2872  * @codeCoverageIgnore
2873  */
2874 function wfQueriesMustScale() {
2875         global $wgMiserMode;
2876         return $wgMiserMode
2877                 || ( SiteStats::pages() > 100000
2878                 && SiteStats::edits() > 1000000
2879                 && SiteStats::users() > 10000 );
2880 }
2881
2882 /**
2883  * Get the path to a specified script file, respecting file
2884  * extensions; this is a wrapper around $wgScriptPath etc.
2885  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
2886  *
2887  * @param string $script Script filename, sans extension
2888  * @return string
2889  */
2890 function wfScript( $script = 'index' ) {
2891         global $wgScriptPath, $wgScript, $wgLoadScript;
2892         if ( $script === 'index' ) {
2893                 return $wgScript;
2894         } elseif ( $script === 'load' ) {
2895                 return $wgLoadScript;
2896         } else {
2897                 return "{$wgScriptPath}/{$script}.php";
2898         }
2899 }
2900
2901 /**
2902  * Get the script URL.
2903  *
2904  * @return string Script URL
2905  */
2906 function wfGetScriptUrl() {
2907         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
2908                 /* as it was called, minus the query string.
2909                  *
2910                  * Some sites use Apache rewrite rules to handle subdomains,
2911                  * and have PHP set up in a weird way that causes PHP_SELF
2912                  * to contain the rewritten URL instead of the one that the
2913                  * outside world sees.
2914                  *
2915                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
2916                  * provides containing the "before" URL.
2917                  */
2918                 return $_SERVER['SCRIPT_NAME'];
2919         } else {
2920                 return $_SERVER['URL'];
2921         }
2922 }
2923
2924 /**
2925  * Convenience function converts boolean values into "true"
2926  * or "false" (string) values
2927  *
2928  * @param bool $value
2929  * @return string
2930  */
2931 function wfBoolToStr( $value ) {
2932         return $value ? 'true' : 'false';
2933 }
2934
2935 /**
2936  * Get a platform-independent path to the null file, e.g. /dev/null
2937  *
2938  * @return string
2939  */
2940 function wfGetNull() {
2941         return wfIsWindows() ? 'NUL' : '/dev/null';
2942 }
2943
2944 /**
2945  * Waits for the replica DBs to catch up to the master position
2946  *
2947  * Use this when updating very large numbers of rows, as in maintenance scripts,
2948  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
2949  *
2950  * By default this waits on the main DB cluster of the current wiki.
2951  * If $cluster is set to "*" it will wait on all DB clusters, including
2952  * external ones. If the lag being waiting on is caused by the code that
2953  * does this check, it makes since to use $ifWritesSince, particularly if
2954  * cluster is "*", to avoid excess overhead.
2955  *
2956  * Never call this function after a big DB write that is still in a transaction.
2957  * This only makes sense after the possible lag inducing changes were committed.
2958  *
2959  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
2960  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
2961  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
2962  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
2963  * @return bool Success (able to connect and no timeouts reached)
2964  * @deprecated since 1.27 Use LBFactory::waitForReplication
2965  */
2966 function wfWaitForSlaves(
2967         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
2968 ) {
2969         if ( $timeout === null ) {
2970                 $timeout = wfIsCLI() ? 60 : 10;
2971         }
2972
2973         if ( $cluster === '*' ) {
2974                 $cluster = false;
2975                 $wiki = false;
2976         } elseif ( $wiki === false ) {
2977                 $wiki = wfWikiID();
2978         }
2979
2980         try {
2981                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2982                 $lbFactory->waitForReplication( [
2983                         'wiki' => $wiki,
2984                         'cluster' => $cluster,
2985                         'timeout' => $timeout,
2986                         // B/C: first argument used to be "max seconds of lag"; ignore such values
2987                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
2988                 ] );
2989         } catch ( DBReplicationWaitError $e ) {
2990                 return false;
2991         }
2992
2993         return true;
2994 }
2995
2996 /**
2997  * Count down from $seconds to zero on the terminal, with a one-second pause
2998  * between showing each number. For use in command-line scripts.
2999  *
3000  * @deprecated since 1.31, use Maintenance::countDown()
3001  *
3002  * @codeCoverageIgnore
3003  * @param int $seconds
3004  */
3005 function wfCountDown( $seconds ) {
3006         for ( $i = $seconds; $i >= 0; $i-- ) {
3007                 if ( $i != $seconds ) {
3008                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3009                 }
3010                 echo $i;
3011                 flush();
3012                 if ( $i ) {
3013                         sleep( 1 );
3014                 }
3015         }
3016         echo "\n";
3017 }
3018
3019 /**
3020  * Replace all invalid characters with '-'.
3021  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
3022  * By default, $wgIllegalFileChars includes ':', '/', '\'.
3023  *
3024  * @param string $name Filename to process
3025  * @return string
3026  */
3027 function wfStripIllegalFilenameChars( $name ) {
3028         global $wgIllegalFileChars;
3029         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3030         $name = preg_replace(
3031                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3032                 '-',
3033                 $name
3034         );
3035         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
3036         $name = wfBaseName( $name );
3037         return $name;
3038 }
3039
3040 /**
3041  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3042  *
3043  * @return int Resulting value of the memory limit.
3044  */
3045 function wfMemoryLimit() {
3046         global $wgMemoryLimit;
3047         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3048         if ( $memlimit != -1 ) {
3049                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3050                 if ( $conflimit == -1 ) {
3051                         wfDebug( "Removing PHP's memory limit\n" );
3052                         Wikimedia\suppressWarnings();
3053                         ini_set( 'memory_limit', $conflimit );
3054                         Wikimedia\restoreWarnings();
3055                         return $conflimit;
3056                 } elseif ( $conflimit > $memlimit ) {
3057                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3058                         Wikimedia\suppressWarnings();
3059                         ini_set( 'memory_limit', $conflimit );
3060                         Wikimedia\restoreWarnings();
3061                         return $conflimit;
3062                 }
3063         }
3064         return $memlimit;
3065 }
3066
3067 /**
3068  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3069  *
3070  * @return int Prior time limit
3071  * @since 1.26
3072  */
3073 function wfTransactionalTimeLimit() {
3074         global $wgTransactionalTimeLimit;
3075
3076         $timeLimit = ini_get( 'max_execution_time' );
3077         // Note that CLI scripts use 0
3078         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3079                 set_time_limit( $wgTransactionalTimeLimit );
3080         }
3081
3082         ignore_user_abort( true ); // ignore client disconnects
3083
3084         return $timeLimit;
3085 }
3086
3087 /**
3088  * Converts shorthand byte notation to integer form
3089  *
3090  * @param string $string
3091  * @param int $default Returned if $string is empty
3092  * @return int
3093  */
3094 function wfShorthandToInteger( $string = '', $default = -1 ) {
3095         $string = trim( $string );
3096         if ( $string === '' ) {
3097                 return $default;
3098         }
3099         $last = $string[strlen( $string ) - 1];
3100         $val = intval( $string );
3101         switch ( $last ) {
3102                 case 'g':
3103                 case 'G':
3104                         $val *= 1024;
3105                         // break intentionally missing
3106                 case 'm':
3107                 case 'M':
3108                         $val *= 1024;
3109                         // break intentionally missing
3110                 case 'k':
3111                 case 'K':
3112                         $val *= 1024;
3113         }
3114
3115         return $val;
3116 }
3117
3118 /**
3119  * Get the normalised IETF language tag
3120  * See unit test for examples.
3121  * See mediawiki.language.bcp47 for the JavaScript implementation.
3122  *
3123  * @deprecated since 1.31, use LanguageCode::bcp47() directly.
3124  *
3125  * @param string $code The language code.
3126  * @return string The language code which complying with BCP 47 standards.
3127  */
3128 function wfBCP47( $code ) {
3129         return LanguageCode::bcp47( $code );
3130 }
3131
3132 /**
3133  * Get a specific cache object.
3134  *
3135  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3136  * @return BagOStuff
3137  */
3138 function wfGetCache( $cacheType ) {
3139         return ObjectCache::getInstance( $cacheType );
3140 }
3141
3142 /**
3143  * Get the main cache object
3144  *
3145  * @return BagOStuff
3146  */
3147 function wfGetMainCache() {
3148         global $wgMainCacheType;
3149         return ObjectCache::getInstance( $wgMainCacheType );
3150 }
3151
3152 /**
3153  * Get the cache object used by the message cache
3154  *
3155  * @return BagOStuff
3156  */
3157 function wfGetMessageCacheStorage() {
3158         global $wgMessageCacheType;
3159         return ObjectCache::getInstance( $wgMessageCacheType );
3160 }
3161
3162 /**
3163  * Get the cache object used by the parser cache
3164  *
3165  * @deprecated since 1.30, use MediaWikiServices::getParserCache()->getCacheStorage()
3166  * @return BagOStuff
3167  */
3168 function wfGetParserCacheStorage() {
3169         global $wgParserCacheType;
3170         return ObjectCache::getInstance( $wgParserCacheType );
3171 }
3172
3173 /**
3174  * Call hook functions defined in $wgHooks
3175  *
3176  * @param string $event Event name
3177  * @param array $args Parameters passed to hook functions
3178  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3179  *
3180  * @return bool True if no handler aborted the hook
3181  * @deprecated since 1.25 - use Hooks::run
3182  */
3183 function wfRunHooks( $event, array $args = [], $deprecatedVersion = null ) {
3184         wfDeprecated( __METHOD__, '1.25' );
3185         return Hooks::run( $event, $args, $deprecatedVersion );
3186 }
3187
3188 /**
3189  * Wrapper around php's unpack.
3190  *
3191  * @param string $format The format string (See php's docs)
3192  * @param string $data A binary string of binary data
3193  * @param int|bool $length The minimum length of $data or false. This is to
3194  *      prevent reading beyond the end of $data. false to disable the check.
3195  *
3196  * Also be careful when using this function to read unsigned 32 bit integer
3197  * because php might make it negative.
3198  *
3199  * @throws MWException If $data not long enough, or if unpack fails
3200  * @return array Associative array of the extracted data
3201  */
3202 function wfUnpack( $format, $data, $length = false ) {
3203         if ( $length !== false ) {
3204                 $realLen = strlen( $data );
3205                 if ( $realLen < $length ) {
3206                         throw new MWException( "Tried to use wfUnpack on a "
3207                                 . "string of length $realLen, but needed one "
3208                                 . "of at least length $length."
3209                         );
3210                 }
3211         }
3212
3213         Wikimedia\suppressWarnings();
3214         $result = unpack( $format, $data );
3215         Wikimedia\restoreWarnings();
3216
3217         if ( $result === false ) {
3218                 // If it cannot extract the packed data.
3219                 throw new MWException( "unpack could not unpack binary data" );
3220         }
3221         return $result;
3222 }
3223
3224 /**
3225  * Determine if an image exists on the 'bad image list'.
3226  *
3227  * The format of MediaWiki:Bad_image_list is as follows:
3228  *    * Only list items (lines starting with "*") are considered
3229  *    * The first link on a line must be a link to a bad image
3230  *    * Any subsequent links on the same line are considered to be exceptions,
3231  *      i.e. articles where the image may occur inline.
3232  *
3233  * @param string $name The image name to check
3234  * @param Title|bool $contextTitle The page on which the image occurs, if known
3235  * @param string $blacklist Wikitext of a file blacklist
3236  * @return bool
3237  */
3238 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3239         # Handle redirects; callers almost always hit wfFindFile() anyway,
3240         # so just use that method because it has a fast process cache.
3241         $file = wfFindFile( $name ); // get the final name
3242         $name = $file ? $file->getTitle()->getDBkey() : $name;
3243
3244         # Run the extension hook
3245         $bad = false;
3246         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3247                 return (bool)$bad;
3248         }
3249
3250         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3251         $key = $cache->makeKey(
3252                 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist )
3253         );
3254         $badImages = $cache->get( $key );
3255
3256         if ( $badImages === false ) { // cache miss
3257                 if ( $blacklist === null ) {
3258                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3259                 }
3260                 # Build the list now
3261                 $badImages = [];
3262                 $lines = explode( "\n", $blacklist );
3263                 foreach ( $lines as $line ) {
3264                         # List items only
3265                         if ( substr( $line, 0, 1 ) !== '*' ) {
3266                                 continue;
3267                         }
3268
3269                         # Find all links
3270                         $m = [];
3271                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3272                                 continue;
3273                         }
3274
3275                         $exceptions = [];
3276                         $imageDBkey = false;
3277                         foreach ( $m[1] as $i => $titleText ) {
3278                                 $title = Title::newFromText( $titleText );
3279                                 if ( !is_null( $title ) ) {
3280                                         if ( $i == 0 ) {
3281                                                 $imageDBkey = $title->getDBkey();
3282                                         } else {
3283                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3284                                         }
3285                                 }
3286                         }
3287
3288                         if ( $imageDBkey !== false ) {
3289                                 $badImages[$imageDBkey] = $exceptions;
3290                         }
3291                 }
3292                 $cache->set( $key, $badImages, 60 );
3293         }
3294
3295         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3296         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3297
3298         return $bad;
3299 }
3300
3301 /**
3302  * Determine whether the client at a given source IP is likely to be able to
3303  * access the wiki via HTTPS.
3304  *
3305  * @param string $ip The IPv4/6 address in the normal human-readable form
3306  * @return bool
3307  */
3308 function wfCanIPUseHTTPS( $ip ) {
3309         $canDo = true;
3310         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3311         return !!$canDo;
3312 }
3313
3314 /**
3315  * Determine input string is represents as infinity
3316  *
3317  * @param string $str The string to determine
3318  * @return bool
3319  * @since 1.25
3320  */
3321 function wfIsInfinity( $str ) {
3322         // These are hardcoded elsewhere in MediaWiki (e.g. mediawiki.special.block.js).
3323         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3324         return in_array( $str, $infinityValues );
3325 }
3326
3327 /**
3328  * Returns true if these thumbnail parameters match one that MediaWiki
3329  * requests from file description pages and/or parser output.
3330  *
3331  * $params is considered non-standard if they involve a non-standard
3332  * width or any non-default parameters aside from width and page number.
3333  * The number of possible files with standard parameters is far less than
3334  * that of all combinations; rate-limiting for them can thus be more generious.
3335  *
3336  * @param File $file
3337  * @param array $params
3338  * @return bool
3339  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3340  */
3341 function wfThumbIsStandard( File $file, array $params ) {
3342         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3343
3344         $multipliers = [ 1 ];
3345         if ( $wgResponsiveImages ) {
3346                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3347                 // @see Linker::processResponsiveImages
3348                 $multipliers[] = 1.5;
3349                 $multipliers[] = 2;
3350         }
3351
3352         $handler = $file->getHandler();
3353         if ( !$handler || !isset( $params['width'] ) ) {
3354                 return false;
3355         }
3356
3357         $basicParams = [];
3358         if ( isset( $params['page'] ) ) {
3359                 $basicParams['page'] = $params['page'];
3360         }
3361
3362         $thumbLimits = [];
3363         $imageLimits = [];
3364         // Expand limits to account for multipliers
3365         foreach ( $multipliers as $multiplier ) {
3366                 $thumbLimits = array_merge( $thumbLimits, array_map(
3367                         function ( $width ) use ( $multiplier ) {
3368                                 return round( $width * $multiplier );
3369                         }, $wgThumbLimits )
3370                 );
3371                 $imageLimits = array_merge( $imageLimits, array_map(
3372                         function ( $pair ) use ( $multiplier ) {
3373                                 return [
3374                                         round( $pair[0] * $multiplier ),
3375                                         round( $pair[1] * $multiplier ),
3376                                 ];
3377                         }, $wgImageLimits )
3378                 );
3379         }
3380
3381         // Check if the width matches one of $wgThumbLimits
3382         if ( in_array( $params['width'], $thumbLimits ) ) {
3383                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3384                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3385                 $handler->normaliseParams( $file, $normalParams );
3386         } else {
3387                 // If not, then check if the width matchs one of $wgImageLimits
3388                 $match = false;
3389                 foreach ( $imageLimits as $pair ) {
3390                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3391                         // Decide whether the thumbnail should be scaled on width or height.
3392                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3393                         $handler->normaliseParams( $file, $normalParams );
3394                         // Check if this standard thumbnail size maps to the given width
3395                         if ( $normalParams['width'] == $params['width'] ) {
3396                                 $match = true;
3397                                 break;
3398                         }
3399                 }
3400                 if ( !$match ) {
3401                         return false; // not standard for description pages
3402                 }
3403         }
3404
3405         // Check that the given values for non-page, non-width, params are just defaults
3406         foreach ( $params as $key => $value ) {
3407                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3408                         return false;
3409                 }
3410         }
3411
3412         return true;
3413 }
3414
3415 /**
3416  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3417  *
3418  * Values that exist in both values will be combined with += (all values of the array
3419  * of $newValues will be added to the values of the array of $baseArray, while values,
3420  * that exists in both, the value of $baseArray will be used).
3421  *
3422  * @param array $baseArray The array where you want to add the values of $newValues to
3423  * @param array $newValues An array with new values
3424  * @return array The combined array
3425  * @since 1.26
3426  */
3427 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3428         // First merge items that are in both arrays
3429         foreach ( $baseArray as $name => &$groupVal ) {
3430                 if ( isset( $newValues[$name] ) ) {
3431                         $groupVal += $newValues[$name];
3432                 }
3433         }
3434         // Now add items that didn't exist yet
3435         $baseArray += $newValues;
3436
3437         return $baseArray;
3438 }
3439
3440 /**
3441  * Get system resource usage of current request context.
3442  * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
3443  * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
3444  *
3445  * @since 1.24
3446  * @return array|bool Resource usage data or false if no data available.
3447  */
3448 function wfGetRusage() {
3449         if ( !function_exists( 'getrusage' ) ) {
3450                 return false;
3451         } elseif ( defined( 'HHVM_VERSION' ) && PHP_OS === 'Linux' ) {
3452                 return getrusage( 2 /* RUSAGE_THREAD */ );
3453         } else {
3454                 return getrusage( 0 /* RUSAGE_SELF */ );
3455         }
3456 }