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  * @since 1.19
 647  *
 648  * @param string $urlPath URL path, potentially containing dot-segments
 649  * @return string URL path with all dot-segments removed
 650  */
 651 function wfRemoveDotSegments( $urlPath ) {
 652         $output = '';
 653         $inputOffset = 0;
 654         $inputLength = strlen( $urlPath );
 655
 656         while ( $inputOffset < $inputLength ) {
 657                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 658                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 659                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 660                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 661                 $trimOutput = false;
 662
 663                 if ( $prefixLengthTwo == './' ) {
 664                         # Step A, remove leading "./"
 665                         $inputOffset += 2;
 666                 } elseif ( $prefixLengthThree == '../' ) {
 667                         # Step A, remove leading "../"
 668                         $inputOffset += 3;
 669                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 670                         # Step B, replace leading "/.$" with "/"
 671                         $inputOffset += 1;
 672                         $urlPath[$inputOffset] = '/';
 673                 } elseif ( $prefixLengthThree == '/./' ) {
 674                         # Step B, replace leading "/./" with "/"
 675                         $inputOffset += 2;
 676                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 677                         # Step C, replace leading "/..$" with "/" and
 678                         # remove last path component in output
 679                         $inputOffset += 2;
 680                         $urlPath[$inputOffset] = '/';
 681                         $trimOutput = true;
 682                 } elseif ( $prefixLengthFour == '/../' ) {
 683                         # Step C, replace leading "/../" with "/" and
 684                         # remove last path component in output
 685                         $inputOffset += 3;
 686                         $trimOutput = true;
 687                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 688                         # Step D, remove "^.$"
 689                         $inputOffset += 1;
 690                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 691                         # Step D, remove "^..$"
 692                         $inputOffset += 2;
 693                 } else {
 694                         # Step E, move leading path segment to output
 695                         if ( $prefixLengthOne == '/' ) {
 696                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 697                         } else {
 698                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 699                         }
 700                         if ( $slashPos === false ) {
 701                                 $output .= substr( $urlPath, $inputOffset );
 702                                 $inputOffset = $inputLength;
 703                         } else {
 704                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 705                                 $inputOffset += $slashPos - $inputOffset;
 706                         }
 707                 }
 708
 709                 if ( $trimOutput ) {
 710                         $slashPos = strrpos( $output, '/' );
 711                         if ( $slashPos === false ) {
 712                                 $output = '';
 713                         } else {
 714                                 $output = substr( $output, 0, $slashPos );
 715                         }
 716                 }
 717         }
 718
 719         return $output;
 720 }
 721
 722 /**
 723  * Returns a regular expression of url protocols
 724  *
 725  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 726  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 727  * @return string
 728  */
 729 function wfUrlProtocols( $includeProtocolRelative = true ) {
 730         global $wgUrlProtocols;
 731
 732         // Cache return values separately based on $includeProtocolRelative
 733         static $withProtRel = null, $withoutProtRel = null;
 734         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 735         if ( !is_null( $cachedValue ) ) {
 736                 return $cachedValue;
 737         }
 738
 739         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 740         // with LocalSettings files from 1.5
 741         if ( is_array( $wgUrlProtocols ) ) {
 742                 $protocols = [];
 743                 foreach ( $wgUrlProtocols as $protocol ) {
 744                         // Filter out '//' if !$includeProtocolRelative
 745                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 746                                 $protocols[] = preg_quote( $protocol, '/' );
 747                         }
 748                 }
 749
 750                 $retval = implode( '|', $protocols );
 751         } else {
 752                 // Ignore $includeProtocolRelative in this case
 753                 // This case exists for pre-1.6 compatibility, and we can safely assume
 754                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 755                 // URLs weren't supported until 1.18
 756                 $retval = $wgUrlProtocols;
 757         }
 758
 759         // Cache return value
 760         if ( $includeProtocolRelative ) {
 761                 $withProtRel = $retval;
 762         } else {
 763                 $withoutProtRel = $retval;
 764         }
 765         return $retval;
 766 }
 767
 768 /**
 769  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 770  * you need a regex that matches all URL protocols but does not match protocol-
 771  * relative URLs
 772  * @return string
 773  */
 774 function wfUrlProtocolsWithoutProtRel() {
 775         return wfUrlProtocols( false );
 776 }
 777
 778 /**
 779  * parse_url() work-alike, but non-broken.  Differences:
 780  *
 781  * 1) Does not raise warnings on bad URLs (just returns false).
 782  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 783  *    protocol-relative URLs) correctly.
 784  * 3) Adds a "delimiter" element to the array (see (2)).
 785  * 4) Verifies that the protocol is on the $wgUrlProtocols whitelist.
 786  * 5) Rejects some invalid URLs that parse_url doesn't, e.g. the empty string or URLs starting with
 787  *    a line feed character.
 788  *
 789  * @param string $url A URL to parse
 790  * @return string[]|bool Bits of the URL in an associative array, or false on failure.
 791  *   Possible fields:
 792  *   - scheme: URI scheme (protocol), e.g. 'http', 'mailto'. Lowercase, always present, but can
 793  *       be an empty string for protocol-relative URLs.
 794  *   - delimiter: either '://', ':' or '//'. Always present.
 795  *   - host: domain name / IP. Always present, but could be an empty string, e.g. for file: URLs.
 796  *   - user: user name, e.g. for HTTP Basic auth URLs such as http://user:pass@example.com/
 797  *       Missing when there is no username.
 798  *   - pass: password, same as above.
 799  *   - path: path including the leading /. Will be missing when empty (e.g. 'http://example.com')
 800  *   - query: query string (as a string; see wfCgiToArray() for parsing it), can be missing.
 801  *   - fragment: the part after #, can be missing.
 802  */
 803 function wfParseUrl( $url ) {
 804         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 805
 806         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 807         // bad that the easiest way to handle them is to just prepend 'http:' and
 808         // strip the protocol out later.
 809         $wasRelative = substr( $url, 0, 2 ) == '//';
 810         if ( $wasRelative ) {
 811                 $url = "http:$url";
 812         }
 813         Wikimedia\suppressWarnings();
 814         $bits = parse_url( $url );
 815         Wikimedia\restoreWarnings();
 816         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 817         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 818         if ( !$bits || !isset( $bits['scheme'] ) ) {
 819                 return false;
 820         }
 821
 822         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 823         $bits['scheme'] = strtolower( $bits['scheme'] );
 824
 825         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 826         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 827                 $bits['delimiter'] = '://';
 828         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 829                 $bits['delimiter'] = ':';
 830                 // parse_url detects for news: and mailto: the host part of an url as path
 831                 // We have to correct this wrong detection
 832                 if ( isset( $bits['path'] ) ) {
 833                         $bits['host'] = $bits['path'];
 834                         $bits['path'] = '';
 835                 }
 836         } else {
 837                 return false;
 838         }
 839
 840         /* Provide an empty host for eg. file:/// urls (see T30627) */
 841         if ( !isset( $bits['host'] ) ) {
 842                 $bits['host'] = '';
 843
 844                 // See T47069
 845                 if ( isset( $bits['path'] ) ) {
 846                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 847                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 848                                 $bits['path'] = '/' . $bits['path'];
 849                         }
 850                 } else {
 851                         $bits['path'] = '';
 852                 }
 853         }
 854
 855         // If the URL was protocol-relative, fix scheme and delimiter
 856         if ( $wasRelative ) {
 857                 $bits['scheme'] = '';
 858                 $bits['delimiter'] = '//';
 859         }
 860         return $bits;
 861 }
 862
 863 /**
 864  * Take a URL, make sure it's expanded to fully qualified, and replace any
 865  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 866  * for more compact display and legibility for local audiences.
 867  *
 868  * @todo handle punycode domains too
 869  *
 870  * @param string $url
 871  * @return string
 872  */
 873 function wfExpandIRI( $url ) {
 874         return preg_replace_callback(
 875                 '/((?:%[89A-F][0-9A-F])+)/i',
 876                 'wfExpandIRI_callback',
 877                 wfExpandUrl( $url )
 878         );
 879 }
 880
 881 /**
 882  * Private callback for wfExpandIRI
 883  * @param array $matches
 884  * @return string
 885  */
 886 function wfExpandIRI_callback( $matches ) {
 887         return urldecode( $matches[1] );
 888 }
 889
 890 /**
 891  * Make URL indexes, appropriate for the el_index field of externallinks.
 892  *
 893  * @param string $url
 894  * @return array
 895  */
 896 function wfMakeUrlIndexes( $url ) {
 897         $bits = wfParseUrl( $url );
 898
 899         // Reverse the labels in the hostname, convert to lower case
 900         // For emails reverse domainpart only
 901         if ( $bits['scheme'] == 'mailto' ) {
 902                 $mailparts = explode( '@', $bits['host'], 2 );
 903                 if ( count( $mailparts ) === 2 ) {
 904                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 905                 } else {
 906                         // No domain specified, don't mangle it
 907                         $domainpart = '';
 908                 }
 909                 $reversedHost = $domainpart . '@' . $mailparts[0];
 910         } else {
 911                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 912         }
 913         // Add an extra dot to the end
 914         // Why? Is it in wrong place in mailto links?
 915         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 916                 $reversedHost .= '.';
 917         }
 918         // Reconstruct the pseudo-URL
 919         $prot = $bits['scheme'];
 920         $index = $prot . $bits['delimiter'] . $reversedHost;
 921         // Leave out user and password. Add the port, path, query and fragment
 922         if ( isset( $bits['port'] ) ) {
 923                 $index .= ':' . $bits['port'];
 924         }
 925         if ( isset( $bits['path'] ) ) {
 926                 $index .= $bits['path'];
 927         } else {
 928                 $index .= '/';
 929         }
 930         if ( isset( $bits['query'] ) ) {
 931                 $index .= '?' . $bits['query'];
 932         }
 933         if ( isset( $bits['fragment'] ) ) {
 934                 $index .= '#' . $bits['fragment'];
 935         }
 936
 937         if ( $prot == '' ) {
 938                 return [ "http:$index", "https:$index" ];
 939         } else {
 940                 return [ $index ];
 941         }
 942 }
 943
 944 /**
 945  * Check whether a given URL has a domain that occurs in a given set of domains
 946  * @param string $url
 947  * @param array $domains Array of domains (strings)
 948  * @return bool True if the host part of $url ends in one of the strings in $domains
 949  */
 950 function wfMatchesDomainList( $url, $domains ) {
 951         $bits = wfParseUrl( $url );
 952         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 953                 $host = '.' . $bits['host'];
 954                 foreach ( (array)$domains as $domain ) {
 955                         $domain = '.' . $domain;
 956                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 957                                 return true;
 958                         }
 959                 }
 960         }
 961         return false;
 962 }
 963
 964 /**
 965  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 966  * In normal operation this is a NOP.
 967  *
 968  * Controlling globals:
 969  * $wgDebugLogFile - points to the log file
 970  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 971  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 972  *
 973  * @since 1.25 support for additional context data
 974  *
 975  * @param string $text
 976  * @param string|bool $dest Destination of the message:
 977  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 978  *     - 'private': excluded from HTML output
 979  *   For backward compatibility, it can also take a boolean:
 980  *     - true: same as 'all'
 981  *     - false: same as 'private'
 982  * @param array $context Additional logging context data
 983  */
 984 function wfDebug( $text, $dest = 'all', array $context = [] ) {
 985         global $wgDebugRawPage, $wgDebugLogPrefix;
 986         global $wgDebugTimestamps;
 987
 988         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 989                 return;
 990         }
 991
 992         $text = trim( $text );
 993
 994         if ( $wgDebugTimestamps ) {
 995                 $context['seconds_elapsed'] = sprintf(
 996                         '%6.4f',
 997                         microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT']
 998                 );
 999                 $context['memory_used'] = sprintf(
1000                         '%5.1fM',
1001                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1002                 );
1003         }
1004
1005         if ( $wgDebugLogPrefix !== '' ) {
1006                 $context['prefix'] = $wgDebugLogPrefix;
1007         }
1008         $context['private'] = ( $dest === false || $dest === 'private' );
1009
1010         $logger = LoggerFactory::getInstance( 'wfDebug' );
1011         $logger->debug( $text, $context );
1012 }
1013
1014 /**
1015  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1016  * @return bool
1017  */
1018 function wfIsDebugRawPage() {
1019         static $cache;
1020         if ( $cache !== null ) {
1021                 return $cache;
1022         }
1023         // Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1024         // phpcs:ignore MediaWiki.Usage.SuperGlobalsUsage.SuperGlobals
1025         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1026                 || (
1027                         isset( $_SERVER['SCRIPT_NAME'] )
1028                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1029                 )
1030         ) {
1031                 $cache = true;
1032         } else {
1033                 $cache = false;
1034         }
1035         return $cache;
1036 }
1037
1038 /**
1039  * Send a line giving PHP memory usage.
1040  *
1041  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1042  */
1043 function wfDebugMem( $exact = false ) {
1044         $mem = memory_get_usage();
1045         if ( !$exact ) {
1046                 $mem = floor( $mem / 1024 ) . ' KiB';
1047         } else {
1048                 $mem .= ' B';
1049         }
1050         wfDebug( "Memory usage: $mem\n" );
1051 }
1052
1053 /**
1054  * Send a line to a supplementary debug log file, if configured, or main debug
1055  * log if not.
1056  *
1057  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1058  * a string filename or an associative array mapping 'destination' to the
1059  * desired filename. The associative array may also contain a 'sample' key
1060  * with an integer value, specifying a sampling factor. Sampled log events
1061  * will be emitted with a 1 in N random chance.
1062  *
1063  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1064  * @since 1.25 support for additional context data
1065  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1066  *
1067  * @param string $logGroup
1068  * @param string $text
1069  * @param string|bool $dest Destination of the message:
1070  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1071  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1072  *       discarded otherwise
1073  *   For backward compatibility, it can also take a boolean:
1074  *     - true: same as 'all'
1075  *     - false: same as 'private'
1076  * @param array $context Additional logging context data
1077  */
1078 function wfDebugLog(
1079         $logGroup, $text, $dest = 'all', array $context = []
1080 ) {
1081         $text = trim( $text );
1082
1083         $logger = LoggerFactory::getInstance( $logGroup );
1084         $context['private'] = ( $dest === false || $dest === 'private' );
1085         $logger->info( $text, $context );
1086 }
1087
1088 /**
1089  * Log for database errors
1090  *
1091  * @since 1.25 support for additional context data
1092  *
1093  * @param string $text Database error message.
1094  * @param array $context Additional logging context data
1095  */
1096 function wfLogDBError( $text, array $context = [] ) {
1097         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1098         $logger->error( trim( $text ), $context );
1099 }
1100
1101 /**
1102  * Throws a warning that $function is deprecated
1103  *
1104  * @param string $function
1105  * @param string|bool $version Version of MediaWiki that the function
1106  *    was deprecated in (Added in 1.19).
1107  * @param string|bool $component Added in 1.19.
1108  * @param int $callerOffset How far up the call stack is the original
1109  *    caller. 2 = function that called the function that called
1110  *    wfDeprecated (Added in 1.20)
1111  *
1112  * @return null
1113  */
1114 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1115         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1116 }
1117
1118 /**
1119  * Send a warning either to the debug log or in a PHP error depending on
1120  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1121  *
1122  * @param string $msg Message to send
1123  * @param int $callerOffset Number of items to go back in the backtrace to
1124  *        find the correct caller (1 = function calling wfWarn, ...)
1125  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1126  *        only used when $wgDevelopmentWarnings is true
1127  */
1128 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1129         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1130 }
1131
1132 /**
1133  * Send a warning as a PHP error and the debug log. This is intended for logging
1134  * warnings in production. For logging development warnings, use WfWarn instead.
1135  *
1136  * @param string $msg Message to send
1137  * @param int $callerOffset Number of items to go back in the backtrace to
1138  *        find the correct caller (1 = function calling wfLogWarning, ...)
1139  * @param int $level PHP error level; defaults to E_USER_WARNING
1140  */
1141 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1142         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1143 }
1144
1145 /**
1146  * Log to a file without getting "file size exceeded" signals.
1147  *
1148  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1149  * send lines to the specified port, prefixed by the specified prefix and a space.
1150  * @since 1.25 support for additional context data
1151  *
1152  * @param string $text
1153  * @param string $file Filename
1154  * @param array $context Additional logging context data
1155  * @throws MWException
1156  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1157  */
1158 function wfErrorLog( $text, $file, array $context = [] ) {
1159         wfDeprecated( __METHOD__, '1.25' );
1160         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1161         $context['destination'] = $file;
1162         $logger->info( trim( $text ), $context );
1163 }
1164
1165 /**
1166  * @todo document
1167  * @todo Move logic to MediaWiki.php
1168  */
1169 function wfLogProfilingData() {
1170         global $wgDebugLogGroups, $wgDebugRawPage;
1171
1172         $context = RequestContext::getMain();
1173         $request = $context->getRequest();
1174
1175         $profiler = Profiler::instance();
1176         $profiler->setContext( $context );
1177         $profiler->logData();
1178
1179         // Send out any buffered statsd metrics as needed
1180         MediaWiki::emitBufferedStatsdData(
1181                 MediaWikiServices::getInstance()->getStatsdDataFactory(),
1182                 $context->getConfig()
1183         );
1184
1185         // Profiling must actually be enabled...
1186         if ( $profiler instanceof ProfilerStub ) {
1187                 return;
1188         }
1189
1190         if ( isset( $wgDebugLogGroups['profileoutput'] )
1191                 && $wgDebugLogGroups['profileoutput'] === false
1192         ) {
1193                 // Explicitly disabled
1194                 return;
1195         }
1196         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1197                 return;
1198         }
1199
1200         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1201         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1202                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1203         }
1204         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1205                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1206         }
1207         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1208                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1209         }
1210         if ( isset( $ctx['forwarded_for'] ) ||
1211                 isset( $ctx['client_ip'] ) ||
1212                 isset( $ctx['from'] ) ) {
1213                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1214         }
1215
1216         // Don't load $wgUser at this late stage just for statistics purposes
1217         // @todo FIXME: We can detect some anons even if it is not loaded.
1218         // See User::getId()
1219         $user = $context->getUser();
1220         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1221
1222         // Command line script uses a FauxRequest object which does not have
1223         // any knowledge about an URL and throw an exception instead.
1224         try {
1225                 $ctx['url'] = urldecode( $request->getRequestURL() );
1226         } catch ( Exception $ignored ) {
1227                 // no-op
1228         }
1229
1230         $ctx['output'] = $profiler->getOutput();
1231
1232         $log = LoggerFactory::getInstance( 'profileoutput' );
1233         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1234 }
1235
1236 /**
1237  * Increment a statistics counter
1238  *
1239  * @param string $key
1240  * @param int $count
1241  * @return void
1242  */
1243 function wfIncrStats( $key, $count = 1 ) {
1244         $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1245         $stats->updateCount( $key, $count );
1246 }
1247
1248 /**
1249  * Check whether the wiki is in read-only mode.
1250  *
1251  * @return bool
1252  */
1253 function wfReadOnly() {
1254         return MediaWikiServices::getInstance()->getReadOnlyMode()
1255                 ->isReadOnly();
1256 }
1257
1258 /**
1259  * Check if the site is in read-only mode and return the message if so
1260  *
1261  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1262  * for replica DB lag. This may result in DB connection being made.
1263  *
1264  * @return string|bool String when in read-only mode; false otherwise
1265  */
1266 function wfReadOnlyReason() {
1267         return MediaWikiServices::getInstance()->getReadOnlyMode()
1268                 ->getReason();
1269 }
1270
1271 /**
1272  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1273  *
1274  * @return string|bool String when in read-only mode; false otherwise
1275  * @since 1.27
1276  */
1277 function wfConfiguredReadOnlyReason() {
1278         return MediaWikiServices::getInstance()->getConfiguredReadOnlyMode()
1279                 ->getReason();
1280 }
1281
1282 /**
1283  * Return a Language object from $langcode
1284  *
1285  * @param Language|string|bool $langcode Either:
1286  *                  - a Language object
1287  *                  - code of the language to get the message for, if it is
1288  *                    a valid code create a language for that language, if
1289  *                    it is a string but not a valid code then make a basic
1290  *                    language object
1291  *                  - a boolean: if it's false then use the global object for
1292  *                    the current user's language (as a fallback for the old parameter
1293  *                    functionality), or if it is true then use global object
1294  *                    for the wiki's content language.
1295  * @return Language
1296  */
1297 function wfGetLangObj( $langcode = false ) {
1298         # Identify which language to get or create a language object for.
1299         # Using is_object here due to Stub objects.
1300         if ( is_object( $langcode ) ) {
1301                 # Great, we already have the object (hopefully)!
1302                 return $langcode;
1303         }
1304
1305         global $wgContLang, $wgLanguageCode;
1306         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1307                 # $langcode is the language code of the wikis content language object.
1308                 # or it is a boolean and value is true
1309                 return $wgContLang;
1310         }
1311
1312         global $wgLang;
1313         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1314                 # $langcode is the language code of user language object.
1315                 # or it was a boolean and value is false
1316                 return $wgLang;
1317         }
1318
1319         $validCodes = array_keys( Language::fetchLanguageNames() );
1320         if ( in_array( $langcode, $validCodes ) ) {
1321                 # $langcode corresponds to a valid language.
1322                 return Language::factory( $langcode );
1323         }
1324
1325         # $langcode is a string, but not a valid language code; use content language.
1326         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1327         return $wgContLang;
1328 }
1329
1330 /**
1331  * This is the function for getting translated interface messages.
1332  *
1333  * @see Message class for documentation how to use them.
1334  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1335  *
1336  * This function replaces all old wfMsg* functions.
1337  *
1338  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1339  * @param mixed $params,... Normal message parameters
1340  * @return Message
1341  *
1342  * @since 1.17
1343  *
1344  * @see Message::__construct
1345  */
1346 function wfMessage( $key /*...*/ ) {
1347         $message = new Message( $key );
1348
1349         // We call Message::params() to reduce code duplication
1350         $params = func_get_args();
1351         array_shift( $params );
1352         if ( $params ) {
1353                 call_user_func_array( [ $message, 'params' ], $params );
1354         }
1355
1356         return $message;
1357 }
1358
1359 /**
1360  * This function accepts multiple message keys and returns a message instance
1361  * for the first message which is non-empty. If all messages are empty then an
1362  * instance of the first message key is returned.
1363  *
1364  * @param string|string[] $keys,... Message keys
1365  * @return Message
1366  *
1367  * @since 1.18
1368  *
1369  * @see Message::newFallbackSequence
1370  */
1371 function wfMessageFallback( /*...*/ ) {
1372         $args = func_get_args();
1373         return call_user_func_array( 'Message::newFallbackSequence', $args );
1374 }
1375
1376 /**
1377  * Replace message parameter keys on the given formatted output.
1378  *
1379  * @param string $message
1380  * @param array $args
1381  * @return string
1382  * @private
1383  */
1384 function wfMsgReplaceArgs( $message, $args ) {
1385         # Fix windows line-endings
1386         # Some messages are split with explode("\n", $msg)
1387         $message = str_replace( "\r", '', $message );
1388
1389         // Replace arguments
1390         if ( is_array( $args ) && $args ) {
1391                 if ( is_array( $args[0] ) ) {
1392                         $args = array_values( $args[0] );
1393                 }
1394                 $replacementKeys = [];
1395                 foreach ( $args as $n => $param ) {
1396                         $replacementKeys['$' . ( $n + 1 )] = $param;
1397                 }
1398                 $message = strtr( $message, $replacementKeys );
1399         }
1400
1401         return $message;
1402 }
1403
1404 /**
1405  * Fetch server name for use in error reporting etc.
1406  * Use real server name if available, so we know which machine
1407  * in a server farm generated the current page.
1408  *
1409  * @return string
1410  */
1411 function wfHostname() {
1412         static $host;
1413         if ( is_null( $host ) ) {
1414                 # Hostname overriding
1415                 global $wgOverrideHostname;
1416                 if ( $wgOverrideHostname !== false ) {
1417                         # Set static and skip any detection
1418                         $host = $wgOverrideHostname;
1419                         return $host;
1420                 }
1421
1422                 if ( function_exists( 'posix_uname' ) ) {
1423                         // This function not present on Windows
1424                         $uname = posix_uname();
1425                 } else {
1426                         $uname = false;
1427                 }
1428                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1429                         $host = $uname['nodename'];
1430                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1431                         # Windows computer name
1432                         $host = getenv( 'COMPUTERNAME' );
1433                 } else {
1434                         # This may be a virtual server.
1435                         $host = $_SERVER['SERVER_NAME'];
1436                 }
1437         }
1438         return $host;
1439 }
1440
1441 /**
1442  * Returns a script tag that stores the amount of time it took MediaWiki to
1443  * handle the request in milliseconds as 'wgBackendResponseTime'.
1444  *
1445  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1446  * hostname of the server handling the request.
1447  *
1448  * @param string $nonce Value from OutputPage::getCSPNonce
1449  * @return string|WrappedString HTML
1450  */
1451 function wfReportTime( $nonce = null ) {
1452         global $wgShowHostnames;
1453
1454         $elapsed = ( microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT'] );
1455         // seconds to milliseconds
1456         $responseTime = round( $elapsed * 1000 );
1457         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1458         if ( $wgShowHostnames ) {
1459                 $reportVars['wgHostname'] = wfHostname();
1460         }
1461         return Skin::makeVariablesScript( $reportVars, $nonce );
1462 }
1463
1464 /**
1465  * Safety wrapper for debug_backtrace().
1466  *
1467  * Will return an empty array if debug_backtrace is disabled, otherwise
1468  * the output from debug_backtrace() (trimmed).
1469  *
1470  * @param int $limit This parameter can be used to limit the number of stack frames returned
1471  *
1472  * @return array Array of backtrace information
1473  */
1474 function wfDebugBacktrace( $limit = 0 ) {
1475         static $disabled = null;
1476
1477         if ( is_null( $disabled ) ) {
1478                 $disabled = !function_exists( 'debug_backtrace' );
1479                 if ( $disabled ) {
1480                         wfDebug( "debug_backtrace() is disabled\n" );
1481                 }
1482         }
1483         if ( $disabled ) {
1484                 return [];
1485         }
1486
1487         if ( $limit ) {
1488                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1489         } else {
1490                 return array_slice( debug_backtrace(), 1 );
1491         }
1492 }
1493
1494 /**
1495  * Get a debug backtrace as a string
1496  *
1497  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1498  *   Defaults to $wgCommandLineMode if unset.
1499  * @return string
1500  * @since 1.25 Supports $raw parameter.
1501  */
1502 function wfBacktrace( $raw = null ) {
1503         global $wgCommandLineMode;
1504
1505         if ( $raw === null ) {
1506                 $raw = $wgCommandLineMode;
1507         }
1508
1509         if ( $raw ) {
1510                 $frameFormat = "%s line %s calls %s()\n";
1511                 $traceFormat = "%s";
1512         } else {
1513                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1514                 $traceFormat = "<ul>\n%s</ul>\n";
1515         }
1516
1517         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1518                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1519                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1520                 $call = $frame['function'];
1521                 if ( !empty( $frame['class'] ) ) {
1522                         $call = $frame['class'] . $frame['type'] . $call;
1523                 }
1524                 return sprintf( $frameFormat, $file, $line, $call );
1525         }, wfDebugBacktrace() );
1526
1527         return sprintf( $traceFormat, implode( '', $frames ) );
1528 }
1529
1530 /**
1531  * Get the name of the function which called this function
1532  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1533  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1534  * wfGetCaller( 3 ) is the parent of that.
1535  *
1536  * @param int $level
1537  * @return string
1538  */
1539 function wfGetCaller( $level = 2 ) {
1540         $backtrace = wfDebugBacktrace( $level + 1 );
1541         if ( isset( $backtrace[$level] ) ) {
1542                 return wfFormatStackFrame( $backtrace[$level] );
1543         } else {
1544                 return 'unknown';
1545         }
1546 }
1547
1548 /**
1549  * Return a string consisting of callers in the stack. Useful sometimes
1550  * for profiling specific points.
1551  *
1552  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1553  * @return string
1554  */
1555 function wfGetAllCallers( $limit = 3 ) {
1556         $trace = array_reverse( wfDebugBacktrace() );
1557         if ( !$limit || $limit > count( $trace ) - 1 ) {
1558                 $limit = count( $trace ) - 1;
1559         }
1560         $trace = array_slice( $trace, -$limit - 1, $limit );
1561         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1562 }
1563
1564 /**
1565  * Return a string representation of frame
1566  *
1567  * @param array $frame
1568  * @return string
1569  */
1570 function wfFormatStackFrame( $frame ) {
1571         if ( !isset( $frame['function'] ) ) {
1572                 return 'NO_FUNCTION_GIVEN';
1573         }
1574         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1575                 $frame['class'] . $frame['type'] . $frame['function'] :
1576                 $frame['function'];
1577 }
1578
1579 /* Some generic result counters, pulled out of SearchEngine */
1580
1581 /**
1582  * @todo document
1583  *
1584  * @param int $offset
1585  * @param int $limit
1586  * @return string
1587  */
1588 function wfShowingResults( $offset, $limit ) {
1589         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1590 }
1591
1592 /**
1593  * Whether the client accept gzip encoding
1594  *
1595  * Uses the Accept-Encoding header to check if the client supports gzip encoding.
1596  * Use this when considering to send a gzip-encoded response to the client.
1597  *
1598  * @param bool $force Forces another check even if we already have a cached result.
1599  * @return bool
1600  */
1601 function wfClientAcceptsGzip( $force = false ) {
1602         static $result = null;
1603         if ( $result === null || $force ) {
1604                 $result = false;
1605                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1606                         # @todo FIXME: We may want to blacklist some broken browsers
1607                         $m = [];
1608                         if ( preg_match(
1609                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1610                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1611                                         $m
1612                                 )
1613                         ) {
1614                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1615                                         $result = false;
1616                                         return $result;
1617                                 }
1618                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1619                                 $result = true;
1620                         }
1621                 }
1622         }
1623         return $result;
1624 }
1625
1626 /**
1627  * Escapes the given text so that it may be output using addWikiText()
1628  * without any linking, formatting, etc. making its way through. This
1629  * is achieved by substituting certain characters with HTML entities.
1630  * As required by the callers, "<nowiki>" is not used.
1631  *
1632  * @param string $text Text to be escaped
1633  * @return string
1634  */
1635 function wfEscapeWikiText( $text ) {
1636         global $wgEnableMagicLinks;
1637         static $repl = null, $repl2 = null;
1638         if ( $repl === null || defined( 'MW_PARSER_TEST' ) || defined( 'MW_PHPUNIT_TEST' ) ) {
1639                 // Tests depend upon being able to change $wgEnableMagicLinks, so don't cache
1640                 // in those situations
1641                 $repl = [
1642                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1643                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1644                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1645                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1646                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1647                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1648                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1649                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1650                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1651                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1652                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1653                         '__' => '_&#95;', '://' => '&#58;//',
1654                 ];
1655
1656                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1657                 // We have to catch everything "\s" matches in PCRE
1658                 foreach ( $magicLinks as $magic ) {
1659                         $repl["$magic "] = "$magic&#32;";
1660                         $repl["$magic\t"] = "$magic&#9;";
1661                         $repl["$magic\r"] = "$magic&#13;";
1662                         $repl["$magic\n"] = "$magic&#10;";
1663                         $repl["$magic\f"] = "$magic&#12;";
1664                 }
1665
1666                 // And handle protocols that don't use "://"
1667                 global $wgUrlProtocols;
1668                 $repl2 = [];
1669                 foreach ( $wgUrlProtocols as $prot ) {
1670                         if ( substr( $prot, -1 ) === ':' ) {
1671                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1672                         }
1673                 }
1674                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1675         }
1676         $text = substr( strtr( "\n$text", $repl ), 1 );
1677         $text = preg_replace( $repl2, '$1&#58;', $text );
1678         return $text;
1679 }
1680
1681 /**
1682  * Sets dest to source and returns the original value of dest
1683  * If source is NULL, it just returns the value, it doesn't set the variable
1684  * If force is true, it will set the value even if source is NULL
1685  *
1686  * @param mixed &$dest
1687  * @param mixed $source
1688  * @param bool $force
1689  * @return mixed
1690  */
1691 function wfSetVar( &$dest, $source, $force = false ) {
1692         $temp = $dest;
1693         if ( !is_null( $source ) || $force ) {
1694                 $dest = $source;
1695         }
1696         return $temp;
1697 }
1698
1699 /**
1700  * As for wfSetVar except setting a bit
1701  *
1702  * @param int &$dest
1703  * @param int $bit
1704  * @param bool $state
1705  *
1706  * @return bool
1707  */
1708 function wfSetBit( &$dest, $bit, $state = true ) {
1709         $temp = (bool)( $dest & $bit );
1710         if ( !is_null( $state ) ) {
1711                 if ( $state ) {
1712                         $dest |= $bit;
1713                 } else {
1714                         $dest &= ~$bit;
1715                 }
1716         }
1717         return $temp;
1718 }
1719
1720 /**
1721  * A wrapper around the PHP function var_export().
1722  * Either print it or add it to the regular output ($wgOut).
1723  *
1724  * @param mixed $var A PHP variable to dump.
1725  */
1726 function wfVarDump( $var ) {
1727         global $wgOut;
1728         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1729         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1730                 print $s;
1731         } else {
1732                 $wgOut->addHTML( $s );
1733         }
1734 }
1735
1736 /**
1737  * Provide a simple HTTP error.
1738  *
1739  * @param int|string $code
1740  * @param string $label
1741  * @param string $desc
1742  */
1743 function wfHttpError( $code, $label, $desc ) {
1744         global $wgOut;
1745         HttpStatus::header( $code );
1746         if ( $wgOut ) {
1747                 $wgOut->disable();
1748                 $wgOut->sendCacheControl();
1749         }
1750
1751         MediaWiki\HeaderCallback::warnIfHeadersSent();
1752         header( 'Content-type: text/html; charset=utf-8' );
1753         print '<!DOCTYPE html>' .
1754                 '<html><head><title>' .
1755                 htmlspecialchars( $label ) .
1756                 '</title></head><body><h1>' .
1757                 htmlspecialchars( $label ) .
1758                 '</h1><p>' .
1759                 nl2br( htmlspecialchars( $desc ) ) .
1760                 "</p></body></html>\n";
1761 }
1762
1763 /**
1764  * Clear away any user-level output buffers, discarding contents.
1765  *
1766  * Suitable for 'starting afresh', for instance when streaming
1767  * relatively large amounts of data without buffering, or wanting to
1768  * output image files without ob_gzhandler's compression.
1769  *
1770  * The optional $resetGzipEncoding parameter controls suppression of
1771  * the Content-Encoding header sent by ob_gzhandler; by default it
1772  * is left. See comments for wfClearOutputBuffers() for why it would
1773  * be used.
1774  *
1775  * Note that some PHP configuration options may add output buffer
1776  * layers which cannot be removed; these are left in place.
1777  *
1778  * @param bool $resetGzipEncoding
1779  */
1780 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1781         if ( $resetGzipEncoding ) {
1782                 // Suppress Content-Encoding and Content-Length
1783                 // headers from OutputHandler::handle.
1784                 global $wgDisableOutputCompression;
1785                 $wgDisableOutputCompression = true;
1786         }
1787         while ( $status = ob_get_status() ) {
1788                 if ( isset( $status['flags'] ) ) {
1789                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1790                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1791                 } elseif ( isset( $status['del'] ) ) {
1792                         $deleteable = $status['del'];
1793                 } else {
1794                         // Guess that any PHP-internal setting can't be removed.
1795                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1796                 }
1797                 if ( !$deleteable ) {
1798                         // Give up, and hope the result doesn't break
1799                         // output behavior.
1800                         break;
1801                 }
1802                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1803                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1804                         break;
1805                 }
1806                 if ( !ob_end_clean() ) {
1807                         // Could not remove output buffer handler; abort now
1808                         // to avoid getting in some kind of infinite loop.
1809                         break;
1810                 }
1811                 if ( $resetGzipEncoding ) {
1812                         if ( $status['name'] == 'ob_gzhandler' ) {
1813                                 // Reset the 'Content-Encoding' field set by this handler
1814                                 // so we can start fresh.
1815                                 header_remove( 'Content-Encoding' );
1816                                 break;
1817                         }
1818                 }
1819         }
1820 }
1821
1822 /**
1823  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1824  *
1825  * Clear away output buffers, but keep the Content-Encoding header
1826  * produced by ob_gzhandler, if any.
1827  *
1828  * This should be used for HTTP 304 responses, where you need to
1829  * preserve the Content-Encoding header of the real result, but
1830  * also need to suppress the output of ob_gzhandler to keep to spec
1831  * and avoid breaking Firefox in rare cases where the headers and
1832  * body are broken over two packets.
1833  */
1834 function wfClearOutputBuffers() {
1835         wfResetOutputBuffers( false );
1836 }
1837
1838 /**
1839  * Converts an Accept-* header into an array mapping string values to quality
1840  * factors
1841  *
1842  * @param string $accept
1843  * @param string $def Default
1844  * @return float[] Associative array of string => float pairs
1845  */
1846 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1847         # No arg means accept anything (per HTTP spec)
1848         if ( !$accept ) {
1849                 return [ $def => 1.0 ];
1850         }
1851
1852         $prefs = [];
1853
1854         $parts = explode( ',', $accept );
1855
1856         foreach ( $parts as $part ) {
1857                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1858                 $values = explode( ';', trim( $part ) );
1859                 $match = [];
1860                 if ( count( $values ) == 1 ) {
1861                         $prefs[$values[0]] = 1.0;
1862                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1863                         $prefs[$values[0]] = floatval( $match[1] );
1864                 }
1865         }
1866
1867         return $prefs;
1868 }
1869
1870 /**
1871  * Checks if a given MIME type matches any of the keys in the given
1872  * array. Basic wildcards are accepted in the array keys.
1873  *
1874  * Returns the matching MIME type (or wildcard) if a match, otherwise
1875  * NULL if no match.
1876  *
1877  * @param string $type
1878  * @param array $avail
1879  * @return string
1880  * @private
1881  */
1882 function mimeTypeMatch( $type, $avail ) {
1883         if ( array_key_exists( $type, $avail ) ) {
1884                 return $type;
1885         } else {
1886                 $mainType = explode( '/', $type )[0];
1887                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1888                         return "$mainType/*";
1889                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1890                         return '*/*';
1891                 } else {
1892                         return null;
1893                 }
1894         }
1895 }
1896
1897 /**
1898  * Returns the 'best' match between a client's requested internet media types
1899  * and the server's list of available types. Each list should be an associative
1900  * array of type to preference (preference is a float between 0.0 and 1.0).
1901  * Wildcards in the types are acceptable.
1902  *
1903  * @param array $cprefs Client's acceptable type list
1904  * @param array $sprefs Server's offered types
1905  * @return string
1906  *
1907  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1908  * XXX: generalize to negotiate other stuff
1909  */
1910 function wfNegotiateType( $cprefs, $sprefs ) {
1911         $combine = [];
1912
1913         foreach ( array_keys( $sprefs ) as $type ) {
1914                 $subType = explode( '/', $type )[1];
1915                 if ( $subType != '*' ) {
1916                         $ckey = mimeTypeMatch( $type, $cprefs );
1917                         if ( $ckey ) {
1918                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1919                         }
1920                 }
1921         }
1922
1923         foreach ( array_keys( $cprefs ) as $type ) {
1924                 $subType = explode( '/', $type )[1];
1925                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1926                         $skey = mimeTypeMatch( $type, $sprefs );
1927                         if ( $skey ) {
1928                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1929                         }
1930                 }
1931         }
1932
1933         $bestq = 0;
1934         $besttype = null;
1935
1936         foreach ( array_keys( $combine ) as $type ) {
1937                 if ( $combine[$type] > $bestq ) {
1938                         $besttype = $type;
1939                         $bestq = $combine[$type];
1940                 }
1941         }
1942
1943         return $besttype;
1944 }
1945
1946 /**
1947  * Reference-counted warning suppression
1948  *
1949  * @deprecated since 1.26, use Wikimedia\suppressWarnings() directly
1950  * @param bool $end
1951  */
1952 function wfSuppressWarnings( $end = false ) {
1953         Wikimedia\suppressWarnings( $end );
1954 }
1955
1956 /**
1957  * @deprecated since 1.26, use Wikimedia\restoreWarnings() directly
1958  * Restore error level to previous value
1959  */
1960 function wfRestoreWarnings() {
1961         Wikimedia\restoreWarnings();
1962 }
1963
1964 /**
1965  * Get a timestamp string in one of various formats
1966  *
1967  * @param mixed $outputtype A timestamp in one of the supported formats, the
1968  *   function will autodetect which format is supplied and act accordingly.
1969  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
1970  * @return string|bool String / false The same date in the format specified in $outputtype or false
1971  */
1972 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
1973         $ret = MWTimestamp::convert( $outputtype, $ts );
1974         if ( $ret === false ) {
1975                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
1976         }
1977         return $ret;
1978 }
1979
1980 /**
1981  * Return a formatted timestamp, or null if input is null.
1982  * For dealing with nullable timestamp columns in the database.
1983  *
1984  * @param int $outputtype
1985  * @param string $ts
1986  * @return string
1987  */
1988 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
1989         if ( is_null( $ts ) ) {
1990                 return null;
1991         } else {
1992                 return wfTimestamp( $outputtype, $ts );
1993         }
1994 }
1995
1996 /**
1997  * Convenience function; returns MediaWiki timestamp for the present time.
1998  *
1999  * @return string
2000  */
2001 function wfTimestampNow() {
2002         # return NOW
2003         return MWTimestamp::now( TS_MW );
2004 }
2005
2006 /**
2007  * Check if the operating system is Windows
2008  *
2009  * @return bool True if it's Windows, false otherwise.
2010  */
2011 function wfIsWindows() {
2012         static $isWindows = null;
2013         if ( $isWindows === null ) {
2014                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2015         }
2016         return $isWindows;
2017 }
2018
2019 /**
2020  * Check if we are running under HHVM
2021  *
2022  * @return bool
2023  */
2024 function wfIsHHVM() {
2025         return defined( 'HHVM_VERSION' );
2026 }
2027
2028 /**
2029  * Check if we are running from the commandline
2030  *
2031  * @since 1.31
2032  * @return bool
2033  */
2034 function wfIsCLI() {
2035         return PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg';
2036 }
2037
2038 /**
2039  * Tries to get the system directory for temporary files. First
2040  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2041  * environment variables are then checked in sequence, then
2042  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2043  *
2044  * NOTE: When possible, use instead the tmpfile() function to create
2045  * temporary files to avoid race conditions on file creation, etc.
2046  *
2047  * @return string
2048  */
2049 function wfTempDir() {
2050         global $wgTmpDirectory;
2051
2052         if ( $wgTmpDirectory !== false ) {
2053                 return $wgTmpDirectory;
2054         }
2055
2056         return TempFSFile::getUsableTempDirectory();
2057 }
2058
2059 /**
2060  * Make directory, and make all parent directories if they don't exist
2061  *
2062  * @param string $dir Full path to directory to create
2063  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2064  * @param string $caller Optional caller param for debugging.
2065  * @throws MWException
2066  * @return bool
2067  */
2068 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2069         global $wgDirectoryMode;
2070
2071         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2072                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2073         }
2074
2075         if ( !is_null( $caller ) ) {
2076                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2077         }
2078
2079         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2080                 return true;
2081         }
2082
2083         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
2084
2085         if ( is_null( $mode ) ) {
2086                 $mode = $wgDirectoryMode;
2087         }
2088
2089         // Turn off the normal warning, we're doing our own below
2090         Wikimedia\suppressWarnings();
2091         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2092         Wikimedia\restoreWarnings();
2093
2094         if ( !$ok ) {
2095                 // directory may have been created on another request since we last checked
2096                 if ( is_dir( $dir ) ) {
2097                         return true;
2098                 }
2099
2100                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2101                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2102         }
2103         return $ok;
2104 }
2105
2106 /**
2107  * Remove a directory and all its content.
2108  * Does not hide error.
2109  * @param string $dir
2110  */
2111 function wfRecursiveRemoveDir( $dir ) {
2112         wfDebug( __FUNCTION__ . "( $dir )\n" );
2113         // taken from https://secure.php.net/manual/en/function.rmdir.php#98622
2114         if ( is_dir( $dir ) ) {
2115                 $objects = scandir( $dir );
2116                 foreach ( $objects as $object ) {
2117                         if ( $object != "." && $object != ".." ) {
2118                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2119                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2120                                 } else {
2121                                         unlink( $dir . '/' . $object );
2122                                 }
2123                         }
2124                 }
2125                 reset( $objects );
2126                 rmdir( $dir );
2127         }
2128 }
2129
2130 /**
2131  * @param int $nr The number to format
2132  * @param int $acc The number of digits after the decimal point, default 2
2133  * @param bool $round Whether or not to round the value, default true
2134  * @return string
2135  */
2136 function wfPercent( $nr, $acc = 2, $round = true ) {
2137         $ret = sprintf( "%.${acc}f", $nr );
2138         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2139 }
2140
2141 /**
2142  * Safety wrapper around ini_get() for boolean settings.
2143  * The values returned from ini_get() are pre-normalized for settings
2144  * set via php.ini or php_flag/php_admin_flag... but *not*
2145  * for those set via php_value/php_admin_value.
2146  *
2147  * It's fairly common for people to use php_value instead of php_flag,
2148  * which can leave you with an 'off' setting giving a false positive
2149  * for code that just takes the ini_get() return value as a boolean.
2150  *
2151  * To make things extra interesting, setting via php_value accepts
2152  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2153  * Unrecognized values go false... again opposite PHP's own coercion
2154  * from string to bool.
2155  *
2156  * Luckily, 'properly' set settings will always come back as '0' or '1',
2157  * so we only have to worry about them and the 'improper' settings.
2158  *
2159  * I frickin' hate PHP... :P
2160  *
2161  * @param string $setting
2162  * @return bool
2163  */
2164 function wfIniGetBool( $setting ) {
2165         return wfStringToBool( ini_get( $setting ) );
2166 }
2167
2168 /**
2169  * Convert string value to boolean, when the following are interpreted as true:
2170  * - on
2171  * - true
2172  * - yes
2173  * - Any number, except 0
2174  * All other strings are interpreted as false.
2175  *
2176  * @param string $val
2177  * @return bool
2178  * @since 1.31
2179  */
2180 function wfStringToBool( $val ) {
2181         $val = strtolower( $val );
2182         // 'on' and 'true' can't have whitespace around them, but '1' can.
2183         return $val == 'on'
2184                 || $val == 'true'
2185                 || $val == 'yes'
2186                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2187 }
2188
2189 /**
2190  * Version of escapeshellarg() that works better on Windows.
2191  *
2192  * Originally, this fixed the incorrect use of single quotes on Windows
2193  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2194  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2195  *
2196  * @param string $args,... strings to escape and glue together,
2197  *  or a single array of strings parameter
2198  * @return string
2199  * @deprecated since 1.30 use MediaWiki\Shell::escape()
2200  */
2201 function wfEscapeShellArg( /*...*/ ) {
2202         $args = func_get_args();
2203
2204         return call_user_func_array( Shell::class . '::escape', $args );
2205 }
2206
2207 /**
2208  * Execute a shell command, with time and memory limits mirrored from the PHP
2209  * configuration if supported.
2210  *
2211  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2212  *   or an array of unescaped arguments, in which case each value will be escaped
2213  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2214  * @param null|mixed &$retval Optional, will receive the program's exit code.
2215  *   (non-zero is usually failure). If there is an error from
2216  *   read, select, or proc_open(), this will be set to -1.
2217  * @param array $environ Optional environment variables which should be
2218  *   added to the executed command environment.
2219  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2220  *   this overwrites the global wgMaxShell* limits.
2221  * @param array $options Array of options:
2222  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2223  *     including errors from limit.sh
2224  *   - profileMethod: By default this function will profile based on the calling
2225  *     method. Set this to a string for an alternative method to profile from
2226  *
2227  * @return string Collected stdout as a string
2228  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2229  */
2230 function wfShellExec( $cmd, &$retval = null, $environ = [],
2231         $limits = [], $options = []
2232 ) {
2233         if ( Shell::isDisabled() ) {
2234                 $retval = 1;
2235                 // Backwards compatibility be upon us...
2236                 return 'Unable to run external programs, proc_open() is disabled.';
2237         }
2238
2239         if ( is_array( $cmd ) ) {
2240                 $cmd = Shell::escape( $cmd );
2241         }
2242
2243         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2244         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2245
2246         try {
2247                 $result = Shell::command( [] )
2248                         ->unsafeParams( (array)$cmd )
2249                         ->environment( $environ )
2250                         ->limits( $limits )
2251                         ->includeStderr( $includeStderr )
2252                         ->profileMethod( $profileMethod )
2253                         // For b/c
2254                         ->restrict( Shell::RESTRICT_NONE )
2255                         ->execute();
2256         } catch ( ProcOpenError $ex ) {
2257                 $retval = -1;
2258                 return '';
2259         }
2260
2261         $retval = $result->getExitCode();
2262
2263         return $result->getStdout();
2264 }
2265
2266 /**
2267  * Execute a shell command, returning both stdout and stderr. Convenience
2268  * function, as all the arguments to wfShellExec can become unwieldy.
2269  *
2270  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2271  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2272  *   or an array of unescaped arguments, in which case each value will be escaped
2273  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2274  * @param null|mixed &$retval Optional, will receive the program's exit code.
2275  *   (non-zero is usually failure)
2276  * @param array $environ Optional environment variables which should be
2277  *   added to the executed command environment.
2278  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2279  *   this overwrites the global wgMaxShell* limits.
2280  * @return string Collected stdout and stderr as a string
2281  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2282  */
2283 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2284         return wfShellExec( $cmd, $retval, $environ, $limits,
2285                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2286 }
2287
2288 /**
2289  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2290  * Note that $parameters should be a flat array and an option with an argument
2291  * should consist of two consecutive items in the array (do not use "--option value").
2292  *
2293  * @deprecated since 1.31, use Shell::makeScriptCommand()
2294  *
2295  * @param string $script MediaWiki cli script path
2296  * @param array $parameters Arguments and options to the script
2297  * @param array $options Associative array of options:
2298  *     'php': The path to the php executable
2299  *     'wrapper': Path to a PHP wrapper to handle the maintenance script
2300  * @return string
2301  */
2302 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2303         global $wgPhpCli;
2304         // Give site config file a chance to run the script in a wrapper.
2305         // The caller may likely want to call wfBasename() on $script.
2306         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2307         $cmd = isset( $options['php'] ) ? [ $options['php'] ] : [ $wgPhpCli ];
2308         if ( isset( $options['wrapper'] ) ) {
2309                 $cmd[] = $options['wrapper'];
2310         }
2311         $cmd[] = $script;
2312         // Escape each parameter for shell
2313         return Shell::escape( array_merge( $cmd, $parameters ) );
2314 }
2315
2316 /**
2317  * wfMerge attempts to merge differences between three texts.
2318  * Returns true for a clean merge and false for failure or a conflict.
2319  *
2320  * @param string $old
2321  * @param string $mine
2322  * @param string $yours
2323  * @param string &$result
2324  * @param string &$mergeAttemptResult
2325  * @return bool
2326  */
2327 function wfMerge( $old, $mine, $yours, &$result, &$mergeAttemptResult = null ) {
2328         global $wgDiff3;
2329
2330         # This check may also protect against code injection in
2331         # case of broken installations.
2332         Wikimedia\suppressWarnings();
2333         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2334         Wikimedia\restoreWarnings();
2335
2336         if ( !$haveDiff3 ) {
2337                 wfDebug( "diff3 not found\n" );
2338                 return false;
2339         }
2340
2341         # Make temporary files
2342         $td = wfTempDir();
2343         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2344         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2345         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2346
2347         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2348         #       a newline character. To avoid this, we normalize the trailing whitespace before
2349         #       creating the diff.
2350
2351         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2352         fclose( $oldtextFile );
2353         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2354         fclose( $mytextFile );
2355         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2356         fclose( $yourtextFile );
2357
2358         # Check for a conflict
2359         $cmd = Shell::escape( $wgDiff3, '-a', '--overlap-only', $mytextName,
2360                 $oldtextName, $yourtextName );
2361         $handle = popen( $cmd, 'r' );
2362
2363         $mergeAttemptResult = '';
2364         do {
2365                 $data = fread( $handle, 8192 );
2366                 if ( strlen( $data ) == 0 ) {
2367                         break;
2368                 }
2369                 $mergeAttemptResult .= $data;
2370         } while ( true );
2371         pclose( $handle );
2372
2373         $conflict = $mergeAttemptResult !== '';
2374
2375         # Merge differences
2376         $cmd = Shell::escape( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2377                 $oldtextName, $yourtextName );
2378         $handle = popen( $cmd, 'r' );
2379         $result = '';
2380         do {
2381                 $data = fread( $handle, 8192 );
2382                 if ( strlen( $data ) == 0 ) {
2383                         break;
2384                 }
2385                 $result .= $data;
2386         } while ( true );
2387         pclose( $handle );
2388         unlink( $mytextName );
2389         unlink( $oldtextName );
2390         unlink( $yourtextName );
2391
2392         if ( $result === '' && $old !== '' && !$conflict ) {
2393                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2394                 $conflict = true;
2395         }
2396         return !$conflict;
2397 }
2398
2399 /**
2400  * Returns unified plain-text diff of two texts.
2401  * "Useful" for machine processing of diffs.
2402  *
2403  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2404  *
2405  * @param string $before The text before the changes.
2406  * @param string $after The text after the changes.
2407  * @param string $params Command-line options for the diff command.
2408  * @return string Unified diff of $before and $after
2409  */
2410 function wfDiff( $before, $after, $params = '-u' ) {
2411         if ( $before == $after ) {
2412                 return '';
2413         }
2414
2415         global $wgDiff;
2416         Wikimedia\suppressWarnings();
2417         $haveDiff = $wgDiff && file_exists( $wgDiff );
2418         Wikimedia\restoreWarnings();
2419
2420         # This check may also protect against code injection in
2421         # case of broken installations.
2422         if ( !$haveDiff ) {
2423                 wfDebug( "diff executable not found\n" );
2424                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2425                 $format = new UnifiedDiffFormatter();
2426                 return $format->format( $diffs );
2427         }
2428
2429         # Make temporary files
2430         $td = wfTempDir();
2431         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2432         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2433
2434         fwrite( $oldtextFile, $before );
2435         fclose( $oldtextFile );
2436         fwrite( $newtextFile, $after );
2437         fclose( $newtextFile );
2438
2439         // Get the diff of the two files
2440         $cmd = "$wgDiff " . $params . ' ' . Shell::escape( $oldtextName, $newtextName );
2441
2442         $h = popen( $cmd, 'r' );
2443         if ( !$h ) {
2444                 unlink( $oldtextName );
2445                 unlink( $newtextName );
2446                 throw new Exception( __METHOD__ . '(): popen() failed' );
2447         }
2448
2449         $diff = '';
2450
2451         do {
2452                 $data = fread( $h, 8192 );
2453                 if ( strlen( $data ) == 0 ) {
2454                         break;
2455                 }
2456                 $diff .= $data;
2457         } while ( true );
2458
2459         // Clean up
2460         pclose( $h );
2461         unlink( $oldtextName );
2462         unlink( $newtextName );
2463
2464         // Kill the --- and +++ lines. They're not useful.
2465         $diff_lines = explode( "\n", $diff );
2466         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2467                 unset( $diff_lines[0] );
2468         }
2469         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2470                 unset( $diff_lines[1] );
2471         }
2472
2473         $diff = implode( "\n", $diff_lines );
2474
2475         return $diff;
2476 }
2477
2478 /**
2479  * This function works like "use VERSION" in Perl, the program will die with a
2480  * backtrace if the current version of PHP is less than the version provided
2481  *
2482  * This is useful for extensions which due to their nature are not kept in sync
2483  * with releases, and might depend on other versions of PHP than the main code
2484  *
2485  * Note: PHP might die due to parsing errors in some cases before it ever
2486  *       manages to call this function, such is life
2487  *
2488  * @see perldoc -f use
2489  *
2490  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2491  *
2492  * @deprecated since 1.30
2493  *
2494  * @throws MWException
2495  */
2496 function wfUsePHP( $req_ver ) {
2497         wfDeprecated( __FUNCTION__, '1.30' );
2498         $php_ver = PHP_VERSION;
2499
2500         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2501                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2502         }
2503 }
2504
2505 /**
2506  * This function works like "use VERSION" in Perl except it checks the version
2507  * of MediaWiki, the program will die with a backtrace if the current version
2508  * of MediaWiki is less than the version provided.
2509  *
2510  * This is useful for extensions which due to their nature are not kept in sync
2511  * with releases
2512  *
2513  * Note: Due to the behavior of PHP's version_compare() which is used in this
2514  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2515  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2516  * targeted version number. For example if you wanted to allow any variation
2517  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2518  * not result in the same comparison due to the internal logic of
2519  * version_compare().
2520  *
2521  * @see perldoc -f use
2522  *
2523  * @deprecated since 1.26, use the "requires" property of extension.json
2524  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2525  * @throws MWException
2526  */
2527 function wfUseMW( $req_ver ) {
2528         global $wgVersion;
2529
2530         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2531                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2532         }
2533 }
2534
2535 /**
2536  * Return the final portion of a pathname.
2537  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2538  * https://bugs.php.net/bug.php?id=33898
2539  *
2540  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2541  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2542  *
2543  * @param string $path
2544  * @param string $suffix String to remove if present
2545  * @return string
2546  */
2547 function wfBaseName( $path, $suffix = '' ) {
2548         if ( $suffix == '' ) {
2549                 $encSuffix = '';
2550         } else {
2551                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2552         }
2553
2554         $matches = [];
2555         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2556                 return $matches[1];
2557         } else {
2558                 return '';
2559         }
2560 }
2561
2562 /**
2563  * Generate a relative path name to the given file.
2564  * May explode on non-matching case-insensitive paths,
2565  * funky symlinks, etc.
2566  *
2567  * @param string $path Absolute destination path including target filename
2568  * @param string $from Absolute source path, directory only
2569  * @return string
2570  */
2571 function wfRelativePath( $path, $from ) {
2572         // Normalize mixed input on Windows...
2573         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2574         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2575
2576         // Trim trailing slashes -- fix for drive root
2577         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2578         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2579
2580         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2581         $against = explode( DIRECTORY_SEPARATOR, $from );
2582
2583         if ( $pieces[0] !== $against[0] ) {
2584                 // Non-matching Windows drive letters?
2585                 // Return a full path.
2586                 return $path;
2587         }
2588
2589         // Trim off common prefix
2590         while ( count( $pieces ) && count( $against )
2591                 && $pieces[0] == $against[0] ) {
2592                 array_shift( $pieces );
2593                 array_shift( $against );
2594         }
2595
2596         // relative dots to bump us to the parent
2597         while ( count( $against ) ) {
2598                 array_unshift( $pieces, '..' );
2599                 array_shift( $against );
2600         }
2601
2602         array_push( $pieces, wfBaseName( $path ) );
2603
2604         return implode( DIRECTORY_SEPARATOR, $pieces );
2605 }
2606
2607 /**
2608  * Reset the session id
2609  *
2610  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2611  * @since 1.22
2612  */
2613 function wfResetSessionID() {
2614         wfDeprecated( __FUNCTION__, '1.27' );
2615         $session = SessionManager::getGlobalSession();
2616         $delay = $session->delaySave();
2617
2618         $session->resetId();
2619
2620         // Make sure a session is started, since that's what the old
2621         // wfResetSessionID() did.
2622         if ( session_id() !== $session->getId() ) {
2623                 wfSetupSession( $session->getId() );
2624         }
2625
2626         ScopedCallback::consume( $delay );
2627 }
2628
2629 /**
2630  * Initialise php session
2631  *
2632  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2633  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2634  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2635  *  here), then calling $session->persist().
2636  * @param bool|string $sessionId
2637  */
2638 function wfSetupSession( $sessionId = false ) {
2639         wfDeprecated( __FUNCTION__, '1.27' );
2640
2641         if ( $sessionId ) {
2642                 session_id( $sessionId );
2643         }
2644
2645         $session = SessionManager::getGlobalSession();
2646         $session->persist();
2647
2648         if ( session_id() !== $session->getId() ) {
2649                 session_id( $session->getId() );
2650         }
2651         Wikimedia\quietCall( 'session_start' );
2652 }
2653
2654 /**
2655  * Get an object from the precompiled serialized directory
2656  *
2657  * @param string $name
2658  * @return mixed The variable on success, false on failure
2659  */
2660 function wfGetPrecompiledData( $name ) {
2661         global $IP;
2662
2663         $file = "$IP/serialized/$name";
2664         if ( file_exists( $file ) ) {
2665                 $blob = file_get_contents( $file );
2666                 if ( $blob ) {
2667                         return unserialize( $blob );
2668                 }
2669         }
2670         return false;
2671 }
2672
2673 /**
2674  * @since 1.32
2675  * @param string[] $data Array with string keys/values to export
2676  * @param string $header
2677  * @return string PHP code
2678  */
2679 function wfMakeStaticArrayFile( array $data, $header = 'Automatically generated' ) {
2680         $format = "\t%s => %s,\n";
2681         $code = "<?php\n"
2682                 . "// " . implode( "\n// ", explode( "\n", $header ) ) . "\n"
2683                 . "return [\n";
2684         foreach ( $data as $key => $value ) {
2685                 $code .= sprintf(
2686                         $format,
2687                         var_export( $key, true ),
2688                         var_export( $value, true )
2689                 );
2690         }
2691         $code .= "];\n";
2692         return $code;
2693 }
2694
2695 /**
2696  * Make a cache key for the local wiki.
2697  *
2698  * @deprecated since 1.30 Call makeKey on a BagOStuff instance
2699  * @param string $args,...
2700  * @return string
2701  */
2702 function wfMemcKey( /*...*/ ) {
2703         return call_user_func_array(
2704                 [ ObjectCache::getLocalClusterInstance(), 'makeKey' ],
2705                 func_get_args()
2706         );
2707 }
2708
2709 /**
2710  * Make a cache key for a foreign DB.
2711  *
2712  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2713  *
2714  * @param string $db
2715  * @param string $prefix
2716  * @param string $args,...
2717  * @return string
2718  */
2719 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
2720         $args = array_slice( func_get_args(), 2 );
2721         $keyspace = $prefix ? "$db-$prefix" : $db;
2722         return call_user_func_array(
2723                 [ ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ],
2724                 [ $keyspace, $args ]
2725         );
2726 }
2727
2728 /**
2729  * Make a cache key with database-agnostic prefix.
2730  *
2731  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
2732  * instead. Must have a prefix as otherwise keys that use a database name
2733  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
2734  *
2735  * @deprecated since 1.30 Call makeGlobalKey on a BagOStuff instance
2736  * @since 1.26
2737  * @param string $args,...
2738  * @return string
2739  */
2740 function wfGlobalCacheKey( /*...*/ ) {
2741         return call_user_func_array(
2742                 [ ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ],
2743                 func_get_args()
2744         );
2745 }
2746
2747 /**
2748  * Get an ASCII string identifying this wiki
2749  * This is used as a prefix in memcached keys
2750  *
2751  * @return string
2752  */
2753 function wfWikiID() {
2754         global $wgDBprefix, $wgDBname;
2755         if ( $wgDBprefix ) {
2756                 return "$wgDBname-$wgDBprefix";
2757         } else {
2758                 return $wgDBname;
2759         }
2760 }
2761
2762 /**
2763  * Split a wiki ID into DB name and table prefix
2764  *
2765  * @param string $wiki
2766  *
2767  * @return array
2768  */
2769 function wfSplitWikiID( $wiki ) {
2770         $bits = explode( '-', $wiki, 2 );
2771         if ( count( $bits ) < 2 ) {
2772                 $bits[] = '';
2773         }
2774         return $bits;
2775 }
2776
2777 /**
2778  * Get a Database object.
2779  *
2780  * @param int $db Index of the connection to get. May be DB_MASTER for the
2781  *            master (for write queries), DB_REPLICA for potentially lagged read
2782  *            queries, or an integer >= 0 for a particular server.
2783  *
2784  * @param string|string[] $groups Query groups. An array of group names that this query
2785  *                belongs to. May contain a single string if the query is only
2786  *                in one group.
2787  *
2788  * @param string|bool $wiki The wiki ID, or false for the current wiki
2789  *
2790  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
2791  * will always return the same object, unless the underlying connection or load
2792  * balancer is manually destroyed.
2793  *
2794  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
2795  * updater to ensure that a proper database is being updated.
2796  *
2797  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
2798  *       on an injected instance of LoadBalancer.
2799  *
2800  * @return \Wikimedia\Rdbms\Database
2801  */
2802 function wfGetDB( $db, $groups = [], $wiki = false ) {
2803         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
2804 }
2805
2806 /**
2807  * Get a load balancer object.
2808  *
2809  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancer()
2810  *              or MediaWikiServices::getDBLoadBalancerFactory() instead.
2811  *
2812  * @param string|bool $wiki Wiki ID, or false for the current wiki
2813  * @return \Wikimedia\Rdbms\LoadBalancer
2814  */
2815 function wfGetLB( $wiki = false ) {
2816         if ( $wiki === false ) {
2817                 return MediaWikiServices::getInstance()->getDBLoadBalancer();
2818         } else {
2819                 $factory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2820                 return $factory->getMainLB( $wiki );
2821         }
2822 }
2823
2824 /**
2825  * Get the load balancer factory object
2826  *
2827  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancerFactory() instead.
2828  *
2829  * @return \Wikimedia\Rdbms\LBFactory
2830  */
2831 function wfGetLBFactory() {
2832         return MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2833 }
2834
2835 /**
2836  * Find a file.
2837  * Shortcut for RepoGroup::singleton()->findFile()
2838  *
2839  * @param string|Title $title String or Title object
2840  * @param array $options Associative array of options (see RepoGroup::findFile)
2841  * @return File|bool File, or false if the file does not exist
2842  */
2843 function wfFindFile( $title, $options = [] ) {
2844         return RepoGroup::singleton()->findFile( $title, $options );
2845 }
2846
2847 /**
2848  * Get an object referring to a locally registered file.
2849  * Returns a valid placeholder object if the file does not exist.
2850  *
2851  * @param Title|string $title
2852  * @return LocalFile|null A File, or null if passed an invalid Title
2853  */
2854 function wfLocalFile( $title ) {
2855         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
2856 }
2857
2858 /**
2859  * Should low-performance queries be disabled?
2860  *
2861  * @return bool
2862  * @codeCoverageIgnore
2863  */
2864 function wfQueriesMustScale() {
2865         global $wgMiserMode;
2866         return $wgMiserMode
2867                 || ( SiteStats::pages() > 100000
2868                 && SiteStats::edits() > 1000000
2869                 && SiteStats::users() > 10000 );
2870 }
2871
2872 /**
2873  * Get the path to a specified script file, respecting file
2874  * extensions; this is a wrapper around $wgScriptPath etc.
2875  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
2876  *
2877  * @param string $script Script filename, sans extension
2878  * @return string
2879  */
2880 function wfScript( $script = 'index' ) {
2881         global $wgScriptPath, $wgScript, $wgLoadScript;
2882         if ( $script === 'index' ) {
2883                 return $wgScript;
2884         } elseif ( $script === 'load' ) {
2885                 return $wgLoadScript;
2886         } else {
2887                 return "{$wgScriptPath}/{$script}.php";
2888         }
2889 }
2890
2891 /**
2892  * Get the script URL.
2893  *
2894  * @return string Script URL
2895  */
2896 function wfGetScriptUrl() {
2897         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
2898                 /* as it was called, minus the query string.
2899                  *
2900                  * Some sites use Apache rewrite rules to handle subdomains,
2901                  * and have PHP set up in a weird way that causes PHP_SELF
2902                  * to contain the rewritten URL instead of the one that the
2903                  * outside world sees.
2904                  *
2905                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
2906                  * provides containing the "before" URL.
2907                  */
2908                 return $_SERVER['SCRIPT_NAME'];
2909         } else {
2910                 return $_SERVER['URL'];
2911         }
2912 }
2913
2914 /**
2915  * Convenience function converts boolean values into "true"
2916  * or "false" (string) values
2917  *
2918  * @param bool $value
2919  * @return string
2920  */
2921 function wfBoolToStr( $value ) {
2922         return $value ? 'true' : 'false';
2923 }
2924
2925 /**
2926  * Get a platform-independent path to the null file, e.g. /dev/null
2927  *
2928  * @return string
2929  */
2930 function wfGetNull() {
2931         return wfIsWindows() ? 'NUL' : '/dev/null';
2932 }
2933
2934 /**
2935  * Waits for the replica DBs to catch up to the master position
2936  *
2937  * Use this when updating very large numbers of rows, as in maintenance scripts,
2938  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
2939  *
2940  * By default this waits on the main DB cluster of the current wiki.
2941  * If $cluster is set to "*" it will wait on all DB clusters, including
2942  * external ones. If the lag being waiting on is caused by the code that
2943  * does this check, it makes since to use $ifWritesSince, particularly if
2944  * cluster is "*", to avoid excess overhead.
2945  *
2946  * Never call this function after a big DB write that is still in a transaction.
2947  * This only makes sense after the possible lag inducing changes were committed.
2948  *
2949  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
2950  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
2951  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
2952  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
2953  * @return bool Success (able to connect and no timeouts reached)
2954  * @deprecated since 1.27 Use LBFactory::waitForReplication
2955  */
2956 function wfWaitForSlaves(
2957         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
2958 ) {
2959         if ( $timeout === null ) {
2960                 $timeout = wfIsCLI() ? 60 : 10;
2961         }
2962
2963         if ( $cluster === '*' ) {
2964                 $cluster = false;
2965                 $wiki = false;
2966         } elseif ( $wiki === false ) {
2967                 $wiki = wfWikiID();
2968         }
2969
2970         try {
2971                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2972                 $lbFactory->waitForReplication( [
2973                         'wiki' => $wiki,
2974                         'cluster' => $cluster,
2975                         'timeout' => $timeout,
2976                         // B/C: first argument used to be "max seconds of lag"; ignore such values
2977                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
2978                 ] );
2979         } catch ( DBReplicationWaitError $e ) {
2980                 return false;
2981         }
2982
2983         return true;
2984 }
2985
2986 /**
2987  * Count down from $seconds to zero on the terminal, with a one-second pause
2988  * between showing each number. For use in command-line scripts.
2989  *
2990  * @deprecated since 1.31, use Maintenance::countDown()
2991  *
2992  * @codeCoverageIgnore
2993  * @param int $seconds
2994  */
2995 function wfCountDown( $seconds ) {
2996         wfDeprecated( __FUNCTION__, '1.31' );
2997         for ( $i = $seconds; $i >= 0; $i-- ) {
2998                 if ( $i != $seconds ) {
2999                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3000                 }
3001                 echo $i;
3002                 flush();
3003                 if ( $i ) {
3004                         sleep( 1 );
3005                 }
3006         }
3007         echo "\n";
3008 }
3009
3010 /**
3011  * Replace all invalid characters with '-'.
3012  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
3013  * By default, $wgIllegalFileChars includes ':', '/', '\'.
3014  *
3015  * @param string $name Filename to process
3016  * @return string
3017  */
3018 function wfStripIllegalFilenameChars( $name ) {
3019         global $wgIllegalFileChars;
3020         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3021         $name = preg_replace(
3022                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3023                 '-',
3024                 $name
3025         );
3026         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
3027         $name = wfBaseName( $name );
3028         return $name;
3029 }
3030
3031 /**
3032  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3033  *
3034  * @return int Resulting value of the memory limit.
3035  */
3036 function wfMemoryLimit() {
3037         global $wgMemoryLimit;
3038         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3039         if ( $memlimit != -1 ) {
3040                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3041                 if ( $conflimit == -1 ) {
3042                         wfDebug( "Removing PHP's memory limit\n" );
3043                         Wikimedia\suppressWarnings();
3044                         ini_set( 'memory_limit', $conflimit );
3045                         Wikimedia\restoreWarnings();
3046                         return $conflimit;
3047                 } elseif ( $conflimit > $memlimit ) {
3048                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3049                         Wikimedia\suppressWarnings();
3050                         ini_set( 'memory_limit', $conflimit );
3051                         Wikimedia\restoreWarnings();
3052                         return $conflimit;
3053                 }
3054         }
3055         return $memlimit;
3056 }
3057
3058 /**
3059  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3060  *
3061  * @return int Prior time limit
3062  * @since 1.26
3063  */
3064 function wfTransactionalTimeLimit() {
3065         global $wgTransactionalTimeLimit;
3066
3067         $timeLimit = ini_get( 'max_execution_time' );
3068         // Note that CLI scripts use 0
3069         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3070                 set_time_limit( $wgTransactionalTimeLimit );
3071         }
3072
3073         ignore_user_abort( true ); // ignore client disconnects
3074
3075         return $timeLimit;
3076 }
3077
3078 /**
3079  * Converts shorthand byte notation to integer form
3080  *
3081  * @param string $string
3082  * @param int $default Returned if $string is empty
3083  * @return int
3084  */
3085 function wfShorthandToInteger( $string = '', $default = -1 ) {
3086         $string = trim( $string );
3087         if ( $string === '' ) {
3088                 return $default;
3089         }
3090         $last = $string[strlen( $string ) - 1];
3091         $val = intval( $string );
3092         switch ( $last ) {
3093                 case 'g':
3094                 case 'G':
3095                         $val *= 1024;
3096                         // break intentionally missing
3097                 case 'm':
3098                 case 'M':
3099                         $val *= 1024;
3100                         // break intentionally missing
3101                 case 'k':
3102                 case 'K':
3103                         $val *= 1024;
3104         }
3105
3106         return $val;
3107 }
3108
3109 /**
3110  * Get the normalised IETF language tag
3111  * See unit test for examples.
3112  * See mediawiki.language.bcp47 for the JavaScript implementation.
3113  *
3114  * @deprecated since 1.31, use LanguageCode::bcp47() directly.
3115  *
3116  * @param string $code The language code.
3117  * @return string The language code which complying with BCP 47 standards.
3118  */
3119 function wfBCP47( $code ) {
3120         return LanguageCode::bcp47( $code );
3121 }
3122
3123 /**
3124  * Get a specific cache object.
3125  *
3126  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3127  * @return BagOStuff
3128  */
3129 function wfGetCache( $cacheType ) {
3130         return ObjectCache::getInstance( $cacheType );
3131 }
3132
3133 /**
3134  * Get the main cache object
3135  *
3136  * @return BagOStuff
3137  */
3138 function wfGetMainCache() {
3139         global $wgMainCacheType;
3140         return ObjectCache::getInstance( $wgMainCacheType );
3141 }
3142
3143 /**
3144  * Get the cache object used by the message cache
3145  *
3146  * @return BagOStuff
3147  */
3148 function wfGetMessageCacheStorage() {
3149         global $wgMessageCacheType;
3150         return ObjectCache::getInstance( $wgMessageCacheType );
3151 }
3152
3153 /**
3154  * Get the cache object used by the parser cache
3155  *
3156  * @deprecated since 1.30, use MediaWikiServices::getParserCache()->getCacheStorage()
3157  * @return BagOStuff
3158  */
3159 function wfGetParserCacheStorage() {
3160         global $wgParserCacheType;
3161         return ObjectCache::getInstance( $wgParserCacheType );
3162 }
3163
3164 /**
3165  * Call hook functions defined in $wgHooks
3166  *
3167  * @param string $event Event name
3168  * @param array $args Parameters passed to hook functions
3169  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3170  *
3171  * @return bool True if no handler aborted the hook
3172  * @deprecated since 1.25 - use Hooks::run
3173  */
3174 function wfRunHooks( $event, array $args = [], $deprecatedVersion = null ) {
3175         wfDeprecated( __METHOD__, '1.25' );
3176         return Hooks::run( $event, $args, $deprecatedVersion );
3177 }
3178
3179 /**
3180  * Wrapper around php's unpack.
3181  *
3182  * @param string $format The format string (See php's docs)
3183  * @param string $data A binary string of binary data
3184  * @param int|bool $length The minimum length of $data or false. This is to
3185  *      prevent reading beyond the end of $data. false to disable the check.
3186  *
3187  * Also be careful when using this function to read unsigned 32 bit integer
3188  * because php might make it negative.
3189  *
3190  * @throws MWException If $data not long enough, or if unpack fails
3191  * @return array Associative array of the extracted data
3192  */
3193 function wfUnpack( $format, $data, $length = false ) {
3194         if ( $length !== false ) {
3195                 $realLen = strlen( $data );
3196                 if ( $realLen < $length ) {
3197                         throw new MWException( "Tried to use wfUnpack on a "
3198                                 . "string of length $realLen, but needed one "
3199                                 . "of at least length $length."
3200                         );
3201                 }
3202         }
3203
3204         Wikimedia\suppressWarnings();
3205         $result = unpack( $format, $data );
3206         Wikimedia\restoreWarnings();
3207
3208         if ( $result === false ) {
3209                 // If it cannot extract the packed data.
3210                 throw new MWException( "unpack could not unpack binary data" );
3211         }
3212         return $result;
3213 }
3214
3215 /**
3216  * Determine if an image exists on the 'bad image list'.
3217  *
3218  * The format of MediaWiki:Bad_image_list is as follows:
3219  *    * Only list items (lines starting with "*") are considered
3220  *    * The first link on a line must be a link to a bad image
3221  *    * Any subsequent links on the same line are considered to be exceptions,
3222  *      i.e. articles where the image may occur inline.
3223  *
3224  * @param string $name The image name to check
3225  * @param Title|bool $contextTitle The page on which the image occurs, if known
3226  * @param string $blacklist Wikitext of a file blacklist
3227  * @return bool
3228  */
3229 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3230         # Handle redirects; callers almost always hit wfFindFile() anyway,
3231         # so just use that method because it has a fast process cache.
3232         $file = wfFindFile( $name ); // get the final name
3233         $name = $file ? $file->getTitle()->getDBkey() : $name;
3234
3235         # Run the extension hook
3236         $bad = false;
3237         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3238                 return (bool)$bad;
3239         }
3240
3241         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3242         $key = $cache->makeKey(
3243                 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist )
3244         );
3245         $badImages = $cache->get( $key );
3246
3247         if ( $badImages === false ) { // cache miss
3248                 if ( $blacklist === null ) {
3249                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3250                 }
3251                 # Build the list now
3252                 $badImages = [];
3253                 $lines = explode( "\n", $blacklist );
3254                 foreach ( $lines as $line ) {
3255                         # List items only
3256                         if ( substr( $line, 0, 1 ) !== '*' ) {
3257                                 continue;
3258                         }
3259
3260                         # Find all links
3261                         $m = [];
3262                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3263                                 continue;
3264                         }
3265
3266                         $exceptions = [];
3267                         $imageDBkey = false;
3268                         foreach ( $m[1] as $i => $titleText ) {
3269                                 $title = Title::newFromText( $titleText );
3270                                 if ( !is_null( $title ) ) {
3271                                         if ( $i == 0 ) {
3272                                                 $imageDBkey = $title->getDBkey();
3273                                         } else {
3274                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3275                                         }
3276                                 }
3277                         }
3278
3279                         if ( $imageDBkey !== false ) {
3280                                 $badImages[$imageDBkey] = $exceptions;
3281                         }
3282                 }
3283                 $cache->set( $key, $badImages, 60 );
3284         }
3285
3286         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3287         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3288
3289         return $bad;
3290 }
3291
3292 /**
3293  * Determine whether the client at a given source IP is likely to be able to
3294  * access the wiki via HTTPS.
3295  *
3296  * @param string $ip The IPv4/6 address in the normal human-readable form
3297  * @return bool
3298  */
3299 function wfCanIPUseHTTPS( $ip ) {
3300         $canDo = true;
3301         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3302         return !!$canDo;
3303 }
3304
3305 /**
3306  * Determine input string is represents as infinity
3307  *
3308  * @param string $str The string to determine
3309  * @return bool
3310  * @since 1.25
3311  */
3312 function wfIsInfinity( $str ) {
3313         // These are hardcoded elsewhere in MediaWiki (e.g. mediawiki.special.block.js).
3314         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3315         return in_array( $str, $infinityValues );
3316 }
3317
3318 /**
3319  * Returns true if these thumbnail parameters match one that MediaWiki
3320  * requests from file description pages and/or parser output.
3321  *
3322  * $params is considered non-standard if they involve a non-standard
3323  * width or any non-default parameters aside from width and page number.
3324  * The number of possible files with standard parameters is far less than
3325  * that of all combinations; rate-limiting for them can thus be more generious.
3326  *
3327  * @param File $file
3328  * @param array $params
3329  * @return bool
3330  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3331  */
3332 function wfThumbIsStandard( File $file, array $params ) {
3333         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3334
3335         $multipliers = [ 1 ];
3336         if ( $wgResponsiveImages ) {
3337                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3338                 // @see Linker::processResponsiveImages
3339                 $multipliers[] = 1.5;
3340                 $multipliers[] = 2;
3341         }
3342
3343         $handler = $file->getHandler();
3344         if ( !$handler || !isset( $params['width'] ) ) {
3345                 return false;
3346         }
3347
3348         $basicParams = [];
3349         if ( isset( $params['page'] ) ) {
3350                 $basicParams['page'] = $params['page'];
3351         }
3352
3353         $thumbLimits = [];
3354         $imageLimits = [];
3355         // Expand limits to account for multipliers
3356         foreach ( $multipliers as $multiplier ) {
3357                 $thumbLimits = array_merge( $thumbLimits, array_map(
3358                         function ( $width ) use ( $multiplier ) {
3359                                 return round( $width * $multiplier );
3360                         }, $wgThumbLimits )
3361                 );
3362                 $imageLimits = array_merge( $imageLimits, array_map(
3363                         function ( $pair ) use ( $multiplier ) {
3364                                 return [
3365                                         round( $pair[0] * $multiplier ),
3366                                         round( $pair[1] * $multiplier ),
3367                                 ];
3368                         }, $wgImageLimits )
3369                 );
3370         }
3371
3372         // Check if the width matches one of $wgThumbLimits
3373         if ( in_array( $params['width'], $thumbLimits ) ) {
3374                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3375                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3376                 $handler->normaliseParams( $file, $normalParams );
3377         } else {
3378                 // If not, then check if the width matchs one of $wgImageLimits
3379                 $match = false;
3380                 foreach ( $imageLimits as $pair ) {
3381                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3382                         // Decide whether the thumbnail should be scaled on width or height.
3383                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3384                         $handler->normaliseParams( $file, $normalParams );
3385                         // Check if this standard thumbnail size maps to the given width
3386                         if ( $normalParams['width'] == $params['width'] ) {
3387                                 $match = true;
3388                                 break;
3389                         }
3390                 }
3391                 if ( !$match ) {
3392                         return false; // not standard for description pages
3393                 }
3394         }
3395
3396         // Check that the given values for non-page, non-width, params are just defaults
3397         foreach ( $params as $key => $value ) {
3398                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3399                         return false;
3400                 }
3401         }
3402
3403         return true;
3404 }
3405
3406 /**
3407  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3408  *
3409  * Values that exist in both values will be combined with += (all values of the array
3410  * of $newValues will be added to the values of the array of $baseArray, while values,
3411  * that exists in both, the value of $baseArray will be used).
3412  *
3413  * @param array $baseArray The array where you want to add the values of $newValues to
3414  * @param array $newValues An array with new values
3415  * @return array The combined array
3416  * @since 1.26
3417  */
3418 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3419         // First merge items that are in both arrays
3420         foreach ( $baseArray as $name => &$groupVal ) {
3421                 if ( isset( $newValues[$name] ) ) {
3422                         $groupVal += $newValues[$name];
3423                 }
3424         }
3425         // Now add items that didn't exist yet
3426         $baseArray += $newValues;
3427
3428         return $baseArray;
3429 }
3430
3431 /**
3432  * Get system resource usage of current request context.
3433  * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
3434  * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
3435  *
3436  * @since 1.24
3437  * @return array|bool Resource usage data or false if no data available.
3438  */
3439 function wfGetRusage() {
3440         if ( !function_exists( 'getrusage' ) ) {
3441                 return false;
3442         } elseif ( defined( 'HHVM_VERSION' ) && PHP_OS === 'Linux' ) {
3443                 return getrusage( 2 /* RUSAGE_THREAD */ );
3444         } else {
3445                 return getrusage( 0 /* RUSAGE_SELF */ );
3446         }
3447 }