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\Linker\LinkTarget;
  28 use MediaWiki\Logger\LoggerFactory;
  29 use MediaWiki\MediaWikiServices;
  30 use MediaWiki\ProcOpenError;
  31 use MediaWiki\Session\SessionManager;
  32 use MediaWiki\Shell\Shell;
  33 use Wikimedia\WrappedString;
  34 use Wikimedia\AtEase\AtEase;
  35
  36 /**
  37  * Load an extension
  38  *
  39  * This queues an extension to be loaded through
  40  * the ExtensionRegistry system.
  41  *
  42  * @param string $ext Name of the extension to load
  43  * @param string|null $path Absolute path of where to find the extension.json file
  44  * @since 1.25
  45  */
  46 function wfLoadExtension( $ext, $path = null ) {
  47         if ( !$path ) {
  48                 global $wgExtensionDirectory;
  49                 $path = "$wgExtensionDirectory/$ext/extension.json";
  50         }
  51         ExtensionRegistry::getInstance()->queue( $path );
  52 }
  53
  54 /**
  55  * Load multiple extensions at once
  56  *
  57  * Same as wfLoadExtension, but more efficient if you
  58  * are loading multiple extensions.
  59  *
  60  * If you want to specify custom paths, you should interact with
  61  * ExtensionRegistry directly.
  62  *
  63  * @see wfLoadExtension
  64  * @param string[] $exts Array of extension names to load
  65  * @since 1.25
  66  */
  67 function wfLoadExtensions( array $exts ) {
  68         global $wgExtensionDirectory;
  69         $registry = ExtensionRegistry::getInstance();
  70         foreach ( $exts as $ext ) {
  71                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
  72         }
  73 }
  74
  75 /**
  76  * Load a skin
  77  *
  78  * @see wfLoadExtension
  79  * @param string $skin Name of the extension to load
  80  * @param string|null $path Absolute path of where to find the skin.json file
  81  * @since 1.25
  82  */
  83 function wfLoadSkin( $skin, $path = null ) {
  84         if ( !$path ) {
  85                 global $wgStyleDirectory;
  86                 $path = "$wgStyleDirectory/$skin/skin.json";
  87         }
  88         ExtensionRegistry::getInstance()->queue( $path );
  89 }
  90
  91 /**
  92  * Load multiple skins at once
  93  *
  94  * @see wfLoadExtensions
  95  * @param string[] $skins Array of extension names to load
  96  * @since 1.25
  97  */
  98 function wfLoadSkins( array $skins ) {
  99         global $wgStyleDirectory;
 100         $registry = ExtensionRegistry::getInstance();
 101         foreach ( $skins as $skin ) {
 102                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 103         }
 104 }
 105
 106 /**
 107  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 108  * @param array $a
 109  * @param array $b
 110  * @return array
 111  */
 112 function wfArrayDiff2( $a, $b ) {
 113         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 114 }
 115
 116 /**
 117  * @param array|string $a
 118  * @param array|string $b
 119  * @return int
 120  */
 121 function wfArrayDiff2_cmp( $a, $b ) {
 122         if ( is_string( $a ) && is_string( $b ) ) {
 123                 return strcmp( $a, $b );
 124         } elseif ( count( $a ) !== count( $b ) ) {
 125                 return count( $a ) <=> count( $b );
 126         } else {
 127                 reset( $a );
 128                 reset( $b );
 129                 while ( key( $a ) !== null && key( $b ) !== null ) {
 130                         $valueA = current( $a );
 131                         $valueB = current( $b );
 132                         $cmp = strcmp( $valueA, $valueB );
 133                         if ( $cmp !== 0 ) {
 134                                 return $cmp;
 135                         }
 136                         next( $a );
 137                         next( $b );
 138                 }
 139                 return 0;
 140         }
 141 }
 142
 143 /**
 144  * Appends to second array if $value differs from that in $default
 145  *
 146  * @param string|int $key
 147  * @param mixed $value
 148  * @param mixed $default
 149  * @param array &$changed Array to alter
 150  * @throws MWException
 151  */
 152 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 153         if ( is_null( $changed ) ) {
 154                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 155         }
 156         if ( $default[$key] !== $value ) {
 157                 $changed[$key] = $value;
 158         }
 159 }
 160
 161 /**
 162  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 163  * e.g.
 164  *     wfMergeErrorArrays(
 165  *       [ [ 'x' ] ],
 166  *       [ [ 'x', '2' ] ],
 167  *       [ [ 'x' ] ],
 168  *       [ [ 'y' ] ]
 169  *     );
 170  * returns:
 171  *     [
 172  *       [ 'x', '2' ],
 173  *       [ 'x' ],
 174  *       [ 'y' ]
 175  *     ]
 176  *
 177  * @param array ...$args
 178  * @return array
 179  */
 180 function wfMergeErrorArrays( ...$args ) {
 181         $out = [];
 182         foreach ( $args as $errors ) {
 183                 foreach ( $errors as $params ) {
 184                         $originalParams = $params;
 185                         if ( $params[0] instanceof MessageSpecifier ) {
 186                                 $msg = $params[0];
 187                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 188                         }
 189                         # @todo FIXME: Sometimes get nested arrays for $params,
 190                         # which leads to E_NOTICEs
 191                         $spec = implode( "\t", $params );
 192                         $out[$spec] = $originalParams;
 193                 }
 194         }
 195         return array_values( $out );
 196 }
 197
 198 /**
 199  * Insert array into another array after the specified *KEY*
 200  *
 201  * @param array $array The array.
 202  * @param array $insert The array to insert.
 203  * @param mixed $after The key to insert after. Callers need to make sure the key is set.
 204  * @return array
 205  */
 206 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 207         // Find the offset of the element to insert after.
 208         $keys = array_keys( $array );
 209         $offsetByKey = array_flip( $keys );
 210
 211         $offset = $offsetByKey[$after];
 212
 213         // Insert at the specified offset
 214         $before = array_slice( $array, 0, $offset + 1, true );
 215         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 216
 217         $output = $before + $insert + $after;
 218
 219         return $output;
 220 }
 221
 222 /**
 223  * Recursively converts the parameter (an object) to an array with the same data
 224  *
 225  * @param object|array $objOrArray
 226  * @param bool $recursive
 227  * @return array
 228  */
 229 function wfObjectToArray( $objOrArray, $recursive = true ) {
 230         $array = [];
 231         if ( is_object( $objOrArray ) ) {
 232                 $objOrArray = get_object_vars( $objOrArray );
 233         }
 234         foreach ( $objOrArray as $key => $value ) {
 235                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 236                         $value = wfObjectToArray( $value );
 237                 }
 238
 239                 $array[$key] = $value;
 240         }
 241
 242         return $array;
 243 }
 244
 245 /**
 246  * Get a random decimal value in the domain of [0, 1), in a way
 247  * not likely to give duplicate values for any realistic
 248  * number of articles.
 249  *
 250  * @note This is designed for use in relation to Special:RandomPage
 251  *       and the page_random database field.
 252  *
 253  * @return string
 254  */
 255 function wfRandom() {
 256         // The maximum random value is "only" 2^31-1, so get two random
 257         // values to reduce the chance of dupes
 258         $max = mt_getrandmax() + 1;
 259         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 260         return $rand;
 261 }
 262
 263 /**
 264  * Get a random string containing a number of pseudo-random hex characters.
 265  *
 266  * @note This is not secure, if you are trying to generate some sort
 267  *       of token please use MWCryptRand instead.
 268  *
 269  * @param int $length The length of the string to generate
 270  * @return string
 271  * @since 1.20
 272  */
 273 function wfRandomString( $length = 32 ) {
 274         $str = '';
 275         for ( $n = 0; $n < $length; $n += 7 ) {
 276                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 277         }
 278         return substr( $str, 0, $length );
 279 }
 280
 281 /**
 282  * We want some things to be included as literal characters in our title URLs
 283  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 284  * all of the following should be safe:
 285  *
 286  * ;:@&=$-_.+!*'(),
 287  *
 288  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 289  * character which should not be encoded. More importantly, google chrome
 290  * always converts %7E back to ~, and converting it in this function can
 291  * cause a redirect loop (T105265).
 292  *
 293  * But + is not safe because it's used to indicate a space; &= are only safe in
 294  * paths and not in queries (and we don't distinguish here); ' seems kind of
 295  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 296  * is reserved, we don't care.  So the list we unescape is:
 297  *
 298  * ;:@$!*(),/~
 299  *
 300  * However, IIS7 redirects fail when the url contains a colon (see T24709),
 301  * so no fancy : for IIS7.
 302  *
 303  * %2F in the page titles seems to fatally break for some reason.
 304  *
 305  * @param string $s
 306  * @return string
 307  */
 308 function wfUrlencode( $s ) {
 309         static $needle;
 310
 311         if ( is_null( $s ) ) {
 312                 // Reset $needle for testing.
 313                 $needle = null;
 314                 return '';
 315         }
 316
 317         if ( is_null( $needle ) ) {
 318                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 319                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 320                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 321                 ) {
 322                         $needle[] = '%3A';
 323                 }
 324         }
 325
 326         $s = urlencode( $s );
 327         $s = str_ireplace(
 328                 $needle,
 329                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 330                 $s
 331         );
 332
 333         return $s;
 334 }
 335
 336 /**
 337  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 338  * "days=7&limit=100". Options in the first array override options in the second.
 339  * Options set to null or false will not be output.
 340  *
 341  * @param array $array1 ( String|Array )
 342  * @param array|null $array2 ( String|Array )
 343  * @param string $prefix
 344  * @return string
 345  */
 346 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 347         if ( !is_null( $array2 ) ) {
 348                 $array1 = $array1 + $array2;
 349         }
 350
 351         $cgi = '';
 352         foreach ( $array1 as $key => $value ) {
 353                 if ( !is_null( $value ) && $value !== false ) {
 354                         if ( $cgi != '' ) {
 355                                 $cgi .= '&';
 356                         }
 357                         if ( $prefix !== '' ) {
 358                                 $key = $prefix . "[$key]";
 359                         }
 360                         if ( is_array( $value ) ) {
 361                                 $firstTime = true;
 362                                 foreach ( $value as $k => $v ) {
 363                                         $cgi .= $firstTime ? '' : '&';
 364                                         if ( is_array( $v ) ) {
 365                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 366                                         } else {
 367                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 368                                         }
 369                                         $firstTime = false;
 370                                 }
 371                         } else {
 372                                 if ( is_object( $value ) ) {
 373                                         $value = $value->__toString();
 374                                 }
 375                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 376                         }
 377                 }
 378         }
 379         return $cgi;
 380 }
 381
 382 /**
 383  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 384  * its argument and returns the same string in array form.  This allows compatibility
 385  * with legacy functions that accept raw query strings instead of nice
 386  * arrays.  Of course, keys and values are urldecode()d.
 387  *
 388  * @param string $query Query string
 389  * @return string[] Array version of input
 390  */
 391 function wfCgiToArray( $query ) {
 392         if ( isset( $query[0] ) && $query[0] == '?' ) {
 393                 $query = substr( $query, 1 );
 394         }
 395         $bits = explode( '&', $query );
 396         $ret = [];
 397         foreach ( $bits as $bit ) {
 398                 if ( $bit === '' ) {
 399                         continue;
 400                 }
 401                 if ( strpos( $bit, '=' ) === false ) {
 402                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 403                         $key = $bit;
 404                         $value = '';
 405                 } else {
 406                         list( $key, $value ) = explode( '=', $bit );
 407                 }
 408                 $key = urldecode( $key );
 409                 $value = urldecode( $value );
 410                 if ( strpos( $key, '[' ) !== false ) {
 411                         $keys = array_reverse( explode( '[', $key ) );
 412                         $key = array_pop( $keys );
 413                         $temp = $value;
 414                         foreach ( $keys as $k ) {
 415                                 $k = substr( $k, 0, -1 );
 416                                 $temp = [ $k => $temp ];
 417                         }
 418                         if ( isset( $ret[$key] ) ) {
 419                                 $ret[$key] = array_merge( $ret[$key], $temp );
 420                         } else {
 421                                 $ret[$key] = $temp;
 422                         }
 423                 } else {
 424                         $ret[$key] = $value;
 425                 }
 426         }
 427         return $ret;
 428 }
 429
 430 /**
 431  * Append a query string to an existing URL, which may or may not already
 432  * have query string parameters already. If so, they will be combined.
 433  *
 434  * @param string $url
 435  * @param string|string[] $query String or associative array
 436  * @return string
 437  */
 438 function wfAppendQuery( $url, $query ) {
 439         if ( is_array( $query ) ) {
 440                 $query = wfArrayToCgi( $query );
 441         }
 442         if ( $query != '' ) {
 443                 // Remove the fragment, if there is one
 444                 $fragment = false;
 445                 $hashPos = strpos( $url, '#' );
 446                 if ( $hashPos !== false ) {
 447                         $fragment = substr( $url, $hashPos );
 448                         $url = substr( $url, 0, $hashPos );
 449                 }
 450
 451                 // Add parameter
 452                 if ( strpos( $url, '?' ) === false ) {
 453                         $url .= '?';
 454                 } else {
 455                         $url .= '&';
 456                 }
 457                 $url .= $query;
 458
 459                 // Put the fragment back
 460                 if ( $fragment !== false ) {
 461                         $url .= $fragment;
 462                 }
 463         }
 464         return $url;
 465 }
 466
 467 /**
 468  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 469  * is correct.
 470  *
 471  * The meaning of the PROTO_* constants is as follows:
 472  * PROTO_HTTP: Output a URL starting with http://
 473  * PROTO_HTTPS: Output a URL starting with https://
 474  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 475  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 476  *    on which protocol was used for the current incoming request
 477  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 478  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 479  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 480  *
 481  * @todo this won't work with current-path-relative URLs
 482  * like "subdir/foo.html", etc.
 483  *
 484  * @param string $url Either fully-qualified or a local path + query
 485  * @param string|int|null $defaultProto One of the PROTO_* constants. Determines the
 486  *    protocol to use if $url or $wgServer is protocol-relative
 487  * @return string|false Fully-qualified URL, current-path-relative URL or false if
 488  *    no valid URL can be constructed
 489  */
 490 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 491         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 492                 $wgHttpsPort;
 493         if ( $defaultProto === PROTO_CANONICAL ) {
 494                 $serverUrl = $wgCanonicalServer;
 495         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 496                 // Make $wgInternalServer fall back to $wgServer if not set
 497                 $serverUrl = $wgInternalServer;
 498         } else {
 499                 $serverUrl = $wgServer;
 500                 if ( $defaultProto === PROTO_CURRENT ) {
 501                         $defaultProto = $wgRequest->getProtocol() . '://';
 502                 }
 503         }
 504
 505         // Analyze $serverUrl to obtain its protocol
 506         $bits = wfParseUrl( $serverUrl );
 507         $serverHasProto = $bits && $bits['scheme'] != '';
 508
 509         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 510                 if ( $serverHasProto ) {
 511                         $defaultProto = $bits['scheme'] . '://';
 512                 } else {
 513                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 514                         // This really isn't supposed to happen. Fall back to HTTP in this
 515                         // ridiculous case.
 516                         $defaultProto = PROTO_HTTP;
 517                 }
 518         }
 519
 520         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 521
 522         if ( substr( $url, 0, 2 ) == '//' ) {
 523                 $url = $defaultProtoWithoutSlashes . $url;
 524         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 525                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 526                 // otherwise leave it alone.
 527                 if ( $serverHasProto ) {
 528                         $url = $serverUrl . $url;
 529                 } else {
 530                         // If an HTTPS URL is synthesized from a protocol-relative $wgServer, allow the
 531                         // user to override the port number (T67184)
 532                         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 533                                 if ( isset( $bits['port'] ) ) {
 534                                         throw new Exception( 'A protocol-relative $wgServer may not contain a port number' );
 535                                 }
 536                                 $url = $defaultProtoWithoutSlashes . $serverUrl . ':' . $wgHttpsPort . $url;
 537                         } else {
 538                                 $url = $defaultProtoWithoutSlashes . $serverUrl . $url;
 539                         }
 540                 }
 541         }
 542
 543         $bits = wfParseUrl( $url );
 544
 545         if ( $bits && isset( $bits['path'] ) ) {
 546                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 547                 return wfAssembleUrl( $bits );
 548         } elseif ( $bits ) {
 549                 # No path to expand
 550                 return $url;
 551         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 552                 # URL is a relative path
 553                 return wfRemoveDotSegments( $url );
 554         }
 555
 556         # Expanded URL is not valid.
 557         return false;
 558 }
 559
 560 /**
 561  * Get the wiki's "server", i.e. the protocol and host part of the URL, with a
 562  * protocol specified using a PROTO_* constant as in wfExpandUrl()
 563  *
 564  * @since 1.32
 565  * @param string|int|null $proto One of the PROTO_* constants.
 566  * @return string The URL
 567  */
 568 function wfGetServerUrl( $proto ) {
 569         $url = wfExpandUrl( '/', $proto );
 570         return substr( $url, 0, -1 );
 571 }
 572
 573 /**
 574  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 575  * if you need to edit part of a URL and put it back together.
 576  *
 577  * This is the basic structure used (brackets contain keys for $urlParts):
 578  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 579  *
 580  * @todo Need to integrate this into wfExpandUrl (see T34168)
 581  *
 582  * @since 1.19
 583  * @param array $urlParts URL parts, as output from wfParseUrl
 584  * @return string URL assembled from its component parts
 585  */
 586 function wfAssembleUrl( $urlParts ) {
 587         $result = '';
 588
 589         if ( isset( $urlParts['delimiter'] ) ) {
 590                 if ( isset( $urlParts['scheme'] ) ) {
 591                         $result .= $urlParts['scheme'];
 592                 }
 593
 594                 $result .= $urlParts['delimiter'];
 595         }
 596
 597         if ( isset( $urlParts['host'] ) ) {
 598                 if ( isset( $urlParts['user'] ) ) {
 599                         $result .= $urlParts['user'];
 600                         if ( isset( $urlParts['pass'] ) ) {
 601                                 $result .= ':' . $urlParts['pass'];
 602                         }
 603                         $result .= '@';
 604                 }
 605
 606                 $result .= $urlParts['host'];
 607
 608                 if ( isset( $urlParts['port'] ) ) {
 609                         $result .= ':' . $urlParts['port'];
 610                 }
 611         }
 612
 613         if ( isset( $urlParts['path'] ) ) {
 614                 $result .= $urlParts['path'];
 615         }
 616
 617         if ( isset( $urlParts['query'] ) ) {
 618                 $result .= '?' . $urlParts['query'];
 619         }
 620
 621         if ( isset( $urlParts['fragment'] ) ) {
 622                 $result .= '#' . $urlParts['fragment'];
 623         }
 624
 625         return $result;
 626 }
 627
 628 /**
 629  * Remove all dot-segments in the provided URL path.  For example,
 630  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 631  * RFC3986 section 5.2.4.
 632  *
 633  * @todo Need to integrate this into wfExpandUrl (see T34168)
 634  *
 635  * @since 1.19
 636  *
 637  * @param string $urlPath URL path, potentially containing dot-segments
 638  * @return string URL path with all dot-segments removed
 639  */
 640 function wfRemoveDotSegments( $urlPath ) {
 641         $output = '';
 642         $inputOffset = 0;
 643         $inputLength = strlen( $urlPath );
 644
 645         while ( $inputOffset < $inputLength ) {
 646                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 647                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 648                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 649                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 650                 $trimOutput = false;
 651
 652                 if ( $prefixLengthTwo == './' ) {
 653                         # Step A, remove leading "./"
 654                         $inputOffset += 2;
 655                 } elseif ( $prefixLengthThree == '../' ) {
 656                         # Step A, remove leading "../"
 657                         $inputOffset += 3;
 658                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 659                         # Step B, replace leading "/.$" with "/"
 660                         $inputOffset += 1;
 661                         $urlPath[$inputOffset] = '/';
 662                 } elseif ( $prefixLengthThree == '/./' ) {
 663                         # Step B, replace leading "/./" with "/"
 664                         $inputOffset += 2;
 665                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 666                         # Step C, replace leading "/..$" with "/" and
 667                         # remove last path component in output
 668                         $inputOffset += 2;
 669                         $urlPath[$inputOffset] = '/';
 670                         $trimOutput = true;
 671                 } elseif ( $prefixLengthFour == '/../' ) {
 672                         # Step C, replace leading "/../" with "/" and
 673                         # remove last path component in output
 674                         $inputOffset += 3;
 675                         $trimOutput = true;
 676                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 677                         # Step D, remove "^.$"
 678                         $inputOffset += 1;
 679                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 680                         # Step D, remove "^..$"
 681                         $inputOffset += 2;
 682                 } else {
 683                         # Step E, move leading path segment to output
 684                         if ( $prefixLengthOne == '/' ) {
 685                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 686                         } else {
 687                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 688                         }
 689                         if ( $slashPos === false ) {
 690                                 $output .= substr( $urlPath, $inputOffset );
 691                                 $inputOffset = $inputLength;
 692                         } else {
 693                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 694                                 $inputOffset += $slashPos - $inputOffset;
 695                         }
 696                 }
 697
 698                 if ( $trimOutput ) {
 699                         $slashPos = strrpos( $output, '/' );
 700                         if ( $slashPos === false ) {
 701                                 $output = '';
 702                         } else {
 703                                 $output = substr( $output, 0, $slashPos );
 704                         }
 705                 }
 706         }
 707
 708         return $output;
 709 }
 710
 711 /**
 712  * Returns a regular expression of url protocols
 713  *
 714  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 715  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 716  * @return string
 717  */
 718 function wfUrlProtocols( $includeProtocolRelative = true ) {
 719         global $wgUrlProtocols;
 720
 721         // Cache return values separately based on $includeProtocolRelative
 722         static $withProtRel = null, $withoutProtRel = null;
 723         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 724         if ( !is_null( $cachedValue ) ) {
 725                 return $cachedValue;
 726         }
 727
 728         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 729         // with LocalSettings files from 1.5
 730         if ( is_array( $wgUrlProtocols ) ) {
 731                 $protocols = [];
 732                 foreach ( $wgUrlProtocols as $protocol ) {
 733                         // Filter out '//' if !$includeProtocolRelative
 734                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 735                                 $protocols[] = preg_quote( $protocol, '/' );
 736                         }
 737                 }
 738
 739                 $retval = implode( '|', $protocols );
 740         } else {
 741                 // Ignore $includeProtocolRelative in this case
 742                 // This case exists for pre-1.6 compatibility, and we can safely assume
 743                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 744                 // URLs weren't supported until 1.18
 745                 $retval = $wgUrlProtocols;
 746         }
 747
 748         // Cache return value
 749         if ( $includeProtocolRelative ) {
 750                 $withProtRel = $retval;
 751         } else {
 752                 $withoutProtRel = $retval;
 753         }
 754         return $retval;
 755 }
 756
 757 /**
 758  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 759  * you need a regex that matches all URL protocols but does not match protocol-
 760  * relative URLs
 761  * @return string
 762  */
 763 function wfUrlProtocolsWithoutProtRel() {
 764         return wfUrlProtocols( false );
 765 }
 766
 767 /**
 768  * parse_url() work-alike, but non-broken.  Differences:
 769  *
 770  * 1) Does not raise warnings on bad URLs (just returns false).
 771  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 772  *    protocol-relative URLs) correctly.
 773  * 3) Adds a "delimiter" element to the array (see (2)).
 774  * 4) Verifies that the protocol is on the $wgUrlProtocols whitelist.
 775  * 5) Rejects some invalid URLs that parse_url doesn't, e.g. the empty string or URLs starting with
 776  *    a line feed character.
 777  *
 778  * @param string $url A URL to parse
 779  * @return string[]|bool Bits of the URL in an associative array, or false on failure.
 780  *   Possible fields:
 781  *   - scheme: URI scheme (protocol), e.g. 'http', 'mailto'. Lowercase, always present, but can
 782  *       be an empty string for protocol-relative URLs.
 783  *   - delimiter: either '://', ':' or '//'. Always present.
 784  *   - host: domain name / IP. Always present, but could be an empty string, e.g. for file: URLs.
 785  *   - user: user name, e.g. for HTTP Basic auth URLs such as http://user:pass@example.com/
 786  *       Missing when there is no username.
 787  *   - pass: password, same as above.
 788  *   - path: path including the leading /. Will be missing when empty (e.g. 'http://example.com')
 789  *   - query: query string (as a string; see wfCgiToArray() for parsing it), can be missing.
 790  *   - fragment: the part after #, can be missing.
 791  */
 792 function wfParseUrl( $url ) {
 793         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 794
 795         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 796         // bad that the easiest way to handle them is to just prepend 'http:' and
 797         // strip the protocol out later.
 798         $wasRelative = substr( $url, 0, 2 ) == '//';
 799         if ( $wasRelative ) {
 800                 $url = "http:$url";
 801         }
 802         AtEase::suppressWarnings();
 803         $bits = parse_url( $url );
 804         AtEase::restoreWarnings();
 805         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 806         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 807         if ( !$bits || !isset( $bits['scheme'] ) ) {
 808                 return false;
 809         }
 810
 811         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 812         $bits['scheme'] = strtolower( $bits['scheme'] );
 813
 814         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 815         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 816                 $bits['delimiter'] = '://';
 817         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 818                 $bits['delimiter'] = ':';
 819                 // parse_url detects for news: and mailto: the host part of an url as path
 820                 // We have to correct this wrong detection
 821                 if ( isset( $bits['path'] ) ) {
 822                         $bits['host'] = $bits['path'];
 823                         $bits['path'] = '';
 824                 }
 825         } else {
 826                 return false;
 827         }
 828
 829         /* Provide an empty host for eg. file:/// urls (see T30627) */
 830         if ( !isset( $bits['host'] ) ) {
 831                 $bits['host'] = '';
 832
 833                 // See T47069
 834                 if ( isset( $bits['path'] ) ) {
 835                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 836                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 837                                 $bits['path'] = '/' . $bits['path'];
 838                         }
 839                 } else {
 840                         $bits['path'] = '';
 841                 }
 842         }
 843
 844         // If the URL was protocol-relative, fix scheme and delimiter
 845         if ( $wasRelative ) {
 846                 $bits['scheme'] = '';
 847                 $bits['delimiter'] = '//';
 848         }
 849         return $bits;
 850 }
 851
 852 /**
 853  * Take a URL, make sure it's expanded to fully qualified, and replace any
 854  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 855  * for more compact display and legibility for local audiences.
 856  *
 857  * @todo handle punycode domains too
 858  *
 859  * @param string $url
 860  * @return string
 861  */
 862 function wfExpandIRI( $url ) {
 863         return preg_replace_callback(
 864                 '/((?:%[89A-F][0-9A-F])+)/i',
 865                 function ( array $matches ) {
 866                         return urldecode( $matches[1] );
 867                 },
 868                 wfExpandUrl( $url )
 869         );
 870 }
 871
 872 /**
 873  * Check whether a given URL has a domain that occurs in a given set of domains
 874  * @param string $url
 875  * @param array $domains Array of domains (strings)
 876  * @return bool True if the host part of $url ends in one of the strings in $domains
 877  */
 878 function wfMatchesDomainList( $url, $domains ) {
 879         $bits = wfParseUrl( $url );
 880         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 881                 $host = '.' . $bits['host'];
 882                 foreach ( (array)$domains as $domain ) {
 883                         $domain = '.' . $domain;
 884                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 885                                 return true;
 886                         }
 887                 }
 888         }
 889         return false;
 890 }
 891
 892 /**
 893  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 894  * In normal operation this is a NOP.
 895  *
 896  * Controlling globals:
 897  * $wgDebugLogFile - points to the log file
 898  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 899  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 900  *
 901  * @since 1.25 support for additional context data
 902  *
 903  * @param string $text
 904  * @param string|bool $dest Destination of the message:
 905  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 906  *     - 'private': excluded from HTML output
 907  *   For backward compatibility, it can also take a boolean:
 908  *     - true: same as 'all'
 909  *     - false: same as 'private'
 910  * @param array $context Additional logging context data
 911  */
 912 function wfDebug( $text, $dest = 'all', array $context = [] ) {
 913         global $wgDebugRawPage, $wgDebugLogPrefix;
 914         global $wgDebugTimestamps;
 915
 916         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 917                 return;
 918         }
 919
 920         $text = trim( $text );
 921
 922         if ( $wgDebugTimestamps ) {
 923                 $context['seconds_elapsed'] = sprintf(
 924                         '%6.4f',
 925                         microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT']
 926                 );
 927                 $context['memory_used'] = sprintf(
 928                         '%5.1fM',
 929                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
 930                 );
 931         }
 932
 933         if ( $wgDebugLogPrefix !== '' ) {
 934                 $context['prefix'] = $wgDebugLogPrefix;
 935         }
 936         $context['private'] = ( $dest === false || $dest === 'private' );
 937
 938         $logger = LoggerFactory::getInstance( 'wfDebug' );
 939         $logger->debug( $text, $context );
 940 }
 941
 942 /**
 943  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 944  * @return bool
 945  */
 946 function wfIsDebugRawPage() {
 947         static $cache;
 948         if ( $cache !== null ) {
 949                 return $cache;
 950         }
 951         // Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 952         // phpcs:ignore MediaWiki.Usage.SuperGlobalsUsage.SuperGlobals
 953         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 954                 || (
 955                         isset( $_SERVER['SCRIPT_NAME'] )
 956                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 957                 )
 958         ) {
 959                 $cache = true;
 960         } else {
 961                 $cache = false;
 962         }
 963         return $cache;
 964 }
 965
 966 /**
 967  * Send a line giving PHP memory usage.
 968  *
 969  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
 970  */
 971 function wfDebugMem( $exact = false ) {
 972         $mem = memory_get_usage();
 973         if ( !$exact ) {
 974                 $mem = floor( $mem / 1024 ) . ' KiB';
 975         } else {
 976                 $mem .= ' B';
 977         }
 978         wfDebug( "Memory usage: $mem\n" );
 979 }
 980
 981 /**
 982  * Send a line to a supplementary debug log file, if configured, or main debug
 983  * log if not.
 984  *
 985  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
 986  * a string filename or an associative array mapping 'destination' to the
 987  * desired filename. The associative array may also contain a 'sample' key
 988  * with an integer value, specifying a sampling factor. Sampled log events
 989  * will be emitted with a 1 in N random chance.
 990  *
 991  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
 992  * @since 1.25 support for additional context data
 993  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
 994  *
 995  * @param string $logGroup
 996  * @param string $text
 997  * @param string|bool $dest Destination of the message:
 998  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 999  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1000  *       discarded otherwise
1001  *   For backward compatibility, it can also take a boolean:
1002  *     - true: same as 'all'
1003  *     - false: same as 'private'
1004  * @param array $context Additional logging context data
1005  */
1006 function wfDebugLog(
1007         $logGroup, $text, $dest = 'all', array $context = []
1008 ) {
1009         $text = trim( $text );
1010
1011         $logger = LoggerFactory::getInstance( $logGroup );
1012         $context['private'] = ( $dest === false || $dest === 'private' );
1013         $logger->info( $text, $context );
1014 }
1015
1016 /**
1017  * Log for database errors
1018  *
1019  * @since 1.25 support for additional context data
1020  *
1021  * @param string $text Database error message.
1022  * @param array $context Additional logging context data
1023  */
1024 function wfLogDBError( $text, array $context = [] ) {
1025         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1026         $logger->error( trim( $text ), $context );
1027 }
1028
1029 /**
1030  * Throws a warning that $function is deprecated
1031  *
1032  * @param string $function Function that is deprecated.
1033  * @param string|bool $version Version of MediaWiki that the function
1034  *    was deprecated in (Added in 1.19).
1035  * @param string|bool $component Component to which the function belongs.
1036  *    If false, it is assumed the function is in MediaWiki core (Added in 1.19).
1037  * @param int $callerOffset How far up the call stack is the original
1038  *    caller. 2 = function that called the function that called
1039  *    wfDeprecated (Added in 1.20).
1040  *
1041  * @throws Exception If the MediaWiki version number is not a string or boolean.
1042  */
1043 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1044         if ( is_string( $version ) || is_bool( $version ) ) {
1045                 MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1046         } else {
1047                 throw new Exception(
1048                         "MediaWiki version must either be a string or a boolean. " .
1049                         "Example valid version: '1.33'"
1050                 );
1051         }
1052 }
1053
1054 /**
1055  * Send a warning either to the debug log or in a PHP error depending on
1056  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1057  *
1058  * @param string $msg Message to send
1059  * @param int $callerOffset Number of items to go back in the backtrace to
1060  *        find the correct caller (1 = function calling wfWarn, ...)
1061  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1062  *        only used when $wgDevelopmentWarnings is true
1063  */
1064 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1065         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1066 }
1067
1068 /**
1069  * Send a warning as a PHP error and the debug log. This is intended for logging
1070  * warnings in production. For logging development warnings, use WfWarn instead.
1071  *
1072  * @param string $msg Message to send
1073  * @param int $callerOffset Number of items to go back in the backtrace to
1074  *        find the correct caller (1 = function calling wfLogWarning, ...)
1075  * @param int $level PHP error level; defaults to E_USER_WARNING
1076  */
1077 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1078         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1079 }
1080
1081 /**
1082  * @todo document
1083  * @todo Move logic to MediaWiki.php
1084  */
1085 function wfLogProfilingData() {
1086         global $wgDebugLogGroups, $wgDebugRawPage;
1087
1088         $context = RequestContext::getMain();
1089         $request = $context->getRequest();
1090
1091         $profiler = Profiler::instance();
1092         $profiler->setContext( $context );
1093         $profiler->logData();
1094
1095         // Send out any buffered statsd metrics as needed
1096         MediaWiki::emitBufferedStatsdData(
1097                 MediaWikiServices::getInstance()->getStatsdDataFactory(),
1098                 $context->getConfig()
1099         );
1100
1101         // Profiling must actually be enabled...
1102         if ( $profiler instanceof ProfilerStub ) {
1103                 return;
1104         }
1105
1106         if ( isset( $wgDebugLogGroups['profileoutput'] )
1107                 && $wgDebugLogGroups['profileoutput'] === false
1108         ) {
1109                 // Explicitly disabled
1110                 return;
1111         }
1112         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1113                 return;
1114         }
1115
1116         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1117         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1118                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1119         }
1120         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1121                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1122         }
1123         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1124                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1125         }
1126         if ( isset( $ctx['forwarded_for'] ) ||
1127                 isset( $ctx['client_ip'] ) ||
1128                 isset( $ctx['from'] ) ) {
1129                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1130         }
1131
1132         // Don't load $wgUser at this late stage just for statistics purposes
1133         // @todo FIXME: We can detect some anons even if it is not loaded.
1134         // See User::getId()
1135         $user = $context->getUser();
1136         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1137
1138         // Command line script uses a FauxRequest object which does not have
1139         // any knowledge about an URL and throw an exception instead.
1140         try {
1141                 $ctx['url'] = urldecode( $request->getRequestURL() );
1142         } catch ( Exception $ignored ) {
1143                 // no-op
1144         }
1145
1146         $ctx['output'] = $profiler->getOutput();
1147
1148         $log = LoggerFactory::getInstance( 'profileoutput' );
1149         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1150 }
1151
1152 /**
1153  * Increment a statistics counter
1154  *
1155  * @param string $key
1156  * @param int $count
1157  * @return void
1158  */
1159 function wfIncrStats( $key, $count = 1 ) {
1160         $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1161         $stats->updateCount( $key, $count );
1162 }
1163
1164 /**
1165  * Check whether the wiki is in read-only mode.
1166  *
1167  * @return bool
1168  */
1169 function wfReadOnly() {
1170         return MediaWikiServices::getInstance()->getReadOnlyMode()
1171                 ->isReadOnly();
1172 }
1173
1174 /**
1175  * Check if the site is in read-only mode and return the message if so
1176  *
1177  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1178  * for replica DB lag. This may result in DB connection being made.
1179  *
1180  * @return string|bool String when in read-only mode; false otherwise
1181  */
1182 function wfReadOnlyReason() {
1183         return MediaWikiServices::getInstance()->getReadOnlyMode()
1184                 ->getReason();
1185 }
1186
1187 /**
1188  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1189  *
1190  * @return string|bool String when in read-only mode; false otherwise
1191  * @since 1.27
1192  */
1193 function wfConfiguredReadOnlyReason() {
1194         return MediaWikiServices::getInstance()->getConfiguredReadOnlyMode()
1195                 ->getReason();
1196 }
1197
1198 /**
1199  * Return a Language object from $langcode
1200  *
1201  * @param Language|string|bool $langcode Either:
1202  *                  - a Language object
1203  *                  - code of the language to get the message for, if it is
1204  *                    a valid code create a language for that language, if
1205  *                    it is a string but not a valid code then make a basic
1206  *                    language object
1207  *                  - a boolean: if it's false then use the global object for
1208  *                    the current user's language (as a fallback for the old parameter
1209  *                    functionality), or if it is true then use global object
1210  *                    for the wiki's content language.
1211  * @return Language
1212  */
1213 function wfGetLangObj( $langcode = false ) {
1214         # Identify which language to get or create a language object for.
1215         # Using is_object here due to Stub objects.
1216         if ( is_object( $langcode ) ) {
1217                 # Great, we already have the object (hopefully)!
1218                 return $langcode;
1219         }
1220
1221         global $wgLanguageCode;
1222         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1223                 # $langcode is the language code of the wikis content language object.
1224                 # or it is a boolean and value is true
1225                 return MediaWikiServices::getInstance()->getContentLanguage();
1226         }
1227
1228         global $wgLang;
1229         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1230                 # $langcode is the language code of user language object.
1231                 # or it was a boolean and value is false
1232                 return $wgLang;
1233         }
1234
1235         $validCodes = array_keys( Language::fetchLanguageNames() );
1236         if ( in_array( $langcode, $validCodes ) ) {
1237                 # $langcode corresponds to a valid language.
1238                 return Language::factory( $langcode );
1239         }
1240
1241         # $langcode is a string, but not a valid language code; use content language.
1242         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1243         return MediaWikiServices::getInstance()->getContentLanguage();
1244 }
1245
1246 /**
1247  * This is the function for getting translated interface messages.
1248  *
1249  * @see Message class for documentation how to use them.
1250  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1251  *
1252  * This function replaces all old wfMsg* functions.
1253  *
1254  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1255  * @param string|string[] ...$params Normal message parameters
1256  * @return Message
1257  *
1258  * @since 1.17
1259  *
1260  * @see Message::__construct
1261  */
1262 function wfMessage( $key, ...$params ) {
1263         $message = new Message( $key );
1264
1265         // We call Message::params() to reduce code duplication
1266         if ( $params ) {
1267                 $message->params( ...$params );
1268         }
1269
1270         return $message;
1271 }
1272
1273 /**
1274  * This function accepts multiple message keys and returns a message instance
1275  * for the first message which is non-empty. If all messages are empty then an
1276  * instance of the first message key is returned.
1277  *
1278  * @param string ...$keys Message keys
1279  * @return Message
1280  *
1281  * @since 1.18
1282  *
1283  * @see Message::newFallbackSequence
1284  */
1285 function wfMessageFallback( ...$keys ) {
1286         return Message::newFallbackSequence( ...$keys );
1287 }
1288
1289 /**
1290  * Replace message parameter keys on the given formatted output.
1291  *
1292  * @param string $message
1293  * @param array $args
1294  * @return string
1295  * @private
1296  */
1297 function wfMsgReplaceArgs( $message, $args ) {
1298         # Fix windows line-endings
1299         # Some messages are split with explode("\n", $msg)
1300         $message = str_replace( "\r", '', $message );
1301
1302         // Replace arguments
1303         if ( is_array( $args ) && $args ) {
1304                 if ( is_array( $args[0] ) ) {
1305                         $args = array_values( $args[0] );
1306                 }
1307                 $replacementKeys = [];
1308                 foreach ( $args as $n => $param ) {
1309                         $replacementKeys['$' . ( $n + 1 )] = $param;
1310                 }
1311                 $message = strtr( $message, $replacementKeys );
1312         }
1313
1314         return $message;
1315 }
1316
1317 /**
1318  * Fetch server name for use in error reporting etc.
1319  * Use real server name if available, so we know which machine
1320  * in a server farm generated the current page.
1321  *
1322  * @return string
1323  */
1324 function wfHostname() {
1325         static $host;
1326         if ( is_null( $host ) ) {
1327                 # Hostname overriding
1328                 global $wgOverrideHostname;
1329                 if ( $wgOverrideHostname !== false ) {
1330                         # Set static and skip any detection
1331                         $host = $wgOverrideHostname;
1332                         return $host;
1333                 }
1334
1335                 if ( function_exists( 'posix_uname' ) ) {
1336                         // This function not present on Windows
1337                         $uname = posix_uname();
1338                 } else {
1339                         $uname = false;
1340                 }
1341                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1342                         $host = $uname['nodename'];
1343                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1344                         # Windows computer name
1345                         $host = getenv( 'COMPUTERNAME' );
1346                 } else {
1347                         # This may be a virtual server.
1348                         $host = $_SERVER['SERVER_NAME'];
1349                 }
1350         }
1351         return $host;
1352 }
1353
1354 /**
1355  * Returns a script tag that stores the amount of time it took MediaWiki to
1356  * handle the request in milliseconds as 'wgBackendResponseTime'.
1357  *
1358  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1359  * hostname of the server handling the request.
1360  *
1361  * @param string|null $nonce Value from OutputPage::getCSPNonce
1362  * @return string|WrappedString HTML
1363  */
1364 function wfReportTime( $nonce = null ) {
1365         global $wgShowHostnames;
1366
1367         $elapsed = ( microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT'] );
1368         // seconds to milliseconds
1369         $responseTime = round( $elapsed * 1000 );
1370         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1371         if ( $wgShowHostnames ) {
1372                 $reportVars['wgHostname'] = wfHostname();
1373         }
1374         return Skin::makeVariablesScript( $reportVars, $nonce );
1375 }
1376
1377 /**
1378  * Safety wrapper for debug_backtrace().
1379  *
1380  * Will return an empty array if debug_backtrace is disabled, otherwise
1381  * the output from debug_backtrace() (trimmed).
1382  *
1383  * @param int $limit This parameter can be used to limit the number of stack frames returned
1384  *
1385  * @return array Array of backtrace information
1386  */
1387 function wfDebugBacktrace( $limit = 0 ) {
1388         static $disabled = null;
1389
1390         if ( is_null( $disabled ) ) {
1391                 $disabled = !function_exists( 'debug_backtrace' );
1392                 if ( $disabled ) {
1393                         wfDebug( "debug_backtrace() is disabled\n" );
1394                 }
1395         }
1396         if ( $disabled ) {
1397                 return [];
1398         }
1399
1400         if ( $limit ) {
1401                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1402         } else {
1403                 return array_slice( debug_backtrace(), 1 );
1404         }
1405 }
1406
1407 /**
1408  * Get a debug backtrace as a string
1409  *
1410  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1411  *   Defaults to $wgCommandLineMode if unset.
1412  * @return string
1413  * @since 1.25 Supports $raw parameter.
1414  */
1415 function wfBacktrace( $raw = null ) {
1416         global $wgCommandLineMode;
1417
1418         if ( $raw === null ) {
1419                 $raw = $wgCommandLineMode;
1420         }
1421
1422         if ( $raw ) {
1423                 $frameFormat = "%s line %s calls %s()\n";
1424                 $traceFormat = "%s";
1425         } else {
1426                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1427                 $traceFormat = "<ul>\n%s</ul>\n";
1428         }
1429
1430         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1431                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1432                 $line = $frame['line'] ?? '-';
1433                 $call = $frame['function'];
1434                 if ( !empty( $frame['class'] ) ) {
1435                         $call = $frame['class'] . $frame['type'] . $call;
1436                 }
1437                 return sprintf( $frameFormat, $file, $line, $call );
1438         }, wfDebugBacktrace() );
1439
1440         return sprintf( $traceFormat, implode( '', $frames ) );
1441 }
1442
1443 /**
1444  * Get the name of the function which called this function
1445  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1446  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1447  * wfGetCaller( 3 ) is the parent of that.
1448  *
1449  * @param int $level
1450  * @return string
1451  */
1452 function wfGetCaller( $level = 2 ) {
1453         $backtrace = wfDebugBacktrace( $level + 1 );
1454         if ( isset( $backtrace[$level] ) ) {
1455                 return wfFormatStackFrame( $backtrace[$level] );
1456         } else {
1457                 return 'unknown';
1458         }
1459 }
1460
1461 /**
1462  * Return a string consisting of callers in the stack. Useful sometimes
1463  * for profiling specific points.
1464  *
1465  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1466  * @return string
1467  */
1468 function wfGetAllCallers( $limit = 3 ) {
1469         $trace = array_reverse( wfDebugBacktrace() );
1470         if ( !$limit || $limit > count( $trace ) - 1 ) {
1471                 $limit = count( $trace ) - 1;
1472         }
1473         $trace = array_slice( $trace, -$limit - 1, $limit );
1474         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1475 }
1476
1477 /**
1478  * Return a string representation of frame
1479  *
1480  * @param array $frame
1481  * @return string
1482  */
1483 function wfFormatStackFrame( $frame ) {
1484         if ( !isset( $frame['function'] ) ) {
1485                 return 'NO_FUNCTION_GIVEN';
1486         }
1487         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1488                 $frame['class'] . $frame['type'] . $frame['function'] :
1489                 $frame['function'];
1490 }
1491
1492 /* Some generic result counters, pulled out of SearchEngine */
1493
1494 /**
1495  * @todo document
1496  *
1497  * @param int $offset
1498  * @param int $limit
1499  * @return string
1500  */
1501 function wfShowingResults( $offset, $limit ) {
1502         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1503 }
1504
1505 /**
1506  * Whether the client accept gzip encoding
1507  *
1508  * Uses the Accept-Encoding header to check if the client supports gzip encoding.
1509  * Use this when considering to send a gzip-encoded response to the client.
1510  *
1511  * @param bool $force Forces another check even if we already have a cached result.
1512  * @return bool
1513  */
1514 function wfClientAcceptsGzip( $force = false ) {
1515         static $result = null;
1516         if ( $result === null || $force ) {
1517                 $result = false;
1518                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1519                         # @todo FIXME: We may want to blacklist some broken browsers
1520                         $m = [];
1521                         if ( preg_match(
1522                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1523                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1524                                         $m
1525                                 )
1526                         ) {
1527                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1528                                         $result = false;
1529                                         return $result;
1530                                 }
1531                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1532                                 $result = true;
1533                         }
1534                 }
1535         }
1536         return $result;
1537 }
1538
1539 /**
1540  * Escapes the given text so that it may be output using addWikiText()
1541  * without any linking, formatting, etc. making its way through. This
1542  * is achieved by substituting certain characters with HTML entities.
1543  * As required by the callers, "<nowiki>" is not used.
1544  *
1545  * @param string $text Text to be escaped
1546  * @param-taint $text escapes_html
1547  * @return string
1548  */
1549 function wfEscapeWikiText( $text ) {
1550         global $wgEnableMagicLinks;
1551         static $repl = null, $repl2 = null;
1552         if ( $repl === null || defined( 'MW_PARSER_TEST' ) || defined( 'MW_PHPUNIT_TEST' ) ) {
1553                 // Tests depend upon being able to change $wgEnableMagicLinks, so don't cache
1554                 // in those situations
1555                 $repl = [
1556                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1557                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1558                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1559                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1560                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1561                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1562                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1563                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1564                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1565                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1566                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1567                         '__' => '_&#95;', '://' => '&#58;//',
1568                 ];
1569
1570                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1571                 // We have to catch everything "\s" matches in PCRE
1572                 foreach ( $magicLinks as $magic ) {
1573                         $repl["$magic "] = "$magic&#32;";
1574                         $repl["$magic\t"] = "$magic&#9;";
1575                         $repl["$magic\r"] = "$magic&#13;";
1576                         $repl["$magic\n"] = "$magic&#10;";
1577                         $repl["$magic\f"] = "$magic&#12;";
1578                 }
1579
1580                 // And handle protocols that don't use "://"
1581                 global $wgUrlProtocols;
1582                 $repl2 = [];
1583                 foreach ( $wgUrlProtocols as $prot ) {
1584                         if ( substr( $prot, -1 ) === ':' ) {
1585                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1586                         }
1587                 }
1588                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1589         }
1590         $text = substr( strtr( "\n$text", $repl ), 1 );
1591         $text = preg_replace( $repl2, '$1&#58;', $text );
1592         return $text;
1593 }
1594
1595 /**
1596  * Sets dest to source and returns the original value of dest
1597  * If source is NULL, it just returns the value, it doesn't set the variable
1598  * If force is true, it will set the value even if source is NULL
1599  *
1600  * @param mixed &$dest
1601  * @param mixed $source
1602  * @param bool $force
1603  * @return mixed
1604  */
1605 function wfSetVar( &$dest, $source, $force = false ) {
1606         $temp = $dest;
1607         if ( !is_null( $source ) || $force ) {
1608                 $dest = $source;
1609         }
1610         return $temp;
1611 }
1612
1613 /**
1614  * As for wfSetVar except setting a bit
1615  *
1616  * @param int &$dest
1617  * @param int $bit
1618  * @param bool $state
1619  *
1620  * @return bool
1621  */
1622 function wfSetBit( &$dest, $bit, $state = true ) {
1623         $temp = (bool)( $dest & $bit );
1624         if ( !is_null( $state ) ) {
1625                 if ( $state ) {
1626                         $dest |= $bit;
1627                 } else {
1628                         $dest &= ~$bit;
1629                 }
1630         }
1631         return $temp;
1632 }
1633
1634 /**
1635  * A wrapper around the PHP function var_export().
1636  * Either print it or add it to the regular output ($wgOut).
1637  *
1638  * @param mixed $var A PHP variable to dump.
1639  */
1640 function wfVarDump( $var ) {
1641         global $wgOut;
1642         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1643         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1644                 print $s;
1645         } else {
1646                 $wgOut->addHTML( $s );
1647         }
1648 }
1649
1650 /**
1651  * Provide a simple HTTP error.
1652  *
1653  * @param int|string $code
1654  * @param string $label
1655  * @param string $desc
1656  */
1657 function wfHttpError( $code, $label, $desc ) {
1658         global $wgOut;
1659         HttpStatus::header( $code );
1660         if ( $wgOut ) {
1661                 $wgOut->disable();
1662                 $wgOut->sendCacheControl();
1663         }
1664
1665         MediaWiki\HeaderCallback::warnIfHeadersSent();
1666         header( 'Content-type: text/html; charset=utf-8' );
1667         print '<!DOCTYPE html>' .
1668                 '<html><head><title>' .
1669                 htmlspecialchars( $label ) .
1670                 '</title></head><body><h1>' .
1671                 htmlspecialchars( $label ) .
1672                 '</h1><p>' .
1673                 nl2br( htmlspecialchars( $desc ) ) .
1674                 "</p></body></html>\n";
1675 }
1676
1677 /**
1678  * Clear away any user-level output buffers, discarding contents.
1679  *
1680  * Suitable for 'starting afresh', for instance when streaming
1681  * relatively large amounts of data without buffering, or wanting to
1682  * output image files without ob_gzhandler's compression.
1683  *
1684  * The optional $resetGzipEncoding parameter controls suppression of
1685  * the Content-Encoding header sent by ob_gzhandler; by default it
1686  * is left. See comments for wfClearOutputBuffers() for why it would
1687  * be used.
1688  *
1689  * Note that some PHP configuration options may add output buffer
1690  * layers which cannot be removed; these are left in place.
1691  *
1692  * @param bool $resetGzipEncoding
1693  */
1694 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1695         if ( $resetGzipEncoding ) {
1696                 // Suppress Content-Encoding and Content-Length
1697                 // headers from OutputHandler::handle.
1698                 global $wgDisableOutputCompression;
1699                 $wgDisableOutputCompression = true;
1700         }
1701         while ( $status = ob_get_status() ) {
1702                 if ( isset( $status['flags'] ) ) {
1703                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1704                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1705                 } elseif ( isset( $status['del'] ) ) {
1706                         $deleteable = $status['del'];
1707                 } else {
1708                         // Guess that any PHP-internal setting can't be removed.
1709                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1710                 }
1711                 if ( !$deleteable ) {
1712                         // Give up, and hope the result doesn't break
1713                         // output behavior.
1714                         break;
1715                 }
1716                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1717                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1718                         break;
1719                 }
1720                 if ( !ob_end_clean() ) {
1721                         // Could not remove output buffer handler; abort now
1722                         // to avoid getting in some kind of infinite loop.
1723                         break;
1724                 }
1725                 if ( $resetGzipEncoding && $status['name'] == 'ob_gzhandler' ) {
1726                         // Reset the 'Content-Encoding' field set by this handler
1727                         // so we can start fresh.
1728                         header_remove( 'Content-Encoding' );
1729                         break;
1730                 }
1731         }
1732 }
1733
1734 /**
1735  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1736  *
1737  * Clear away output buffers, but keep the Content-Encoding header
1738  * produced by ob_gzhandler, if any.
1739  *
1740  * This should be used for HTTP 304 responses, where you need to
1741  * preserve the Content-Encoding header of the real result, but
1742  * also need to suppress the output of ob_gzhandler to keep to spec
1743  * and avoid breaking Firefox in rare cases where the headers and
1744  * body are broken over two packets.
1745  */
1746 function wfClearOutputBuffers() {
1747         wfResetOutputBuffers( false );
1748 }
1749
1750 /**
1751  * Converts an Accept-* header into an array mapping string values to quality
1752  * factors
1753  *
1754  * @param string $accept
1755  * @param string $def Default
1756  * @return float[] Associative array of string => float pairs
1757  */
1758 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1759         # No arg means accept anything (per HTTP spec)
1760         if ( !$accept ) {
1761                 return [ $def => 1.0 ];
1762         }
1763
1764         $prefs = [];
1765
1766         $parts = explode( ',', $accept );
1767
1768         foreach ( $parts as $part ) {
1769                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1770                 $values = explode( ';', trim( $part ) );
1771                 $match = [];
1772                 if ( count( $values ) == 1 ) {
1773                         $prefs[$values[0]] = 1.0;
1774                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1775                         $prefs[$values[0]] = floatval( $match[1] );
1776                 }
1777         }
1778
1779         return $prefs;
1780 }
1781
1782 /**
1783  * Checks if a given MIME type matches any of the keys in the given
1784  * array. Basic wildcards are accepted in the array keys.
1785  *
1786  * Returns the matching MIME type (or wildcard) if a match, otherwise
1787  * NULL if no match.
1788  *
1789  * @param string $type
1790  * @param array $avail
1791  * @return string
1792  * @private
1793  */
1794 function mimeTypeMatch( $type, $avail ) {
1795         if ( array_key_exists( $type, $avail ) ) {
1796                 return $type;
1797         } else {
1798                 $mainType = explode( '/', $type )[0];
1799                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1800                         return "$mainType/*";
1801                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1802                         return '*/*';
1803                 } else {
1804                         return null;
1805                 }
1806         }
1807 }
1808
1809 /**
1810  * Returns the 'best' match between a client's requested internet media types
1811  * and the server's list of available types. Each list should be an associative
1812  * array of type to preference (preference is a float between 0.0 and 1.0).
1813  * Wildcards in the types are acceptable.
1814  *
1815  * @param array $cprefs Client's acceptable type list
1816  * @param array $sprefs Server's offered types
1817  * @return string
1818  *
1819  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1820  * XXX: generalize to negotiate other stuff
1821  */
1822 function wfNegotiateType( $cprefs, $sprefs ) {
1823         $combine = [];
1824
1825         foreach ( array_keys( $sprefs ) as $type ) {
1826                 $subType = explode( '/', $type )[1];
1827                 if ( $subType != '*' ) {
1828                         $ckey = mimeTypeMatch( $type, $cprefs );
1829                         if ( $ckey ) {
1830                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1831                         }
1832                 }
1833         }
1834
1835         foreach ( array_keys( $cprefs ) as $type ) {
1836                 $subType = explode( '/', $type )[1];
1837                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1838                         $skey = mimeTypeMatch( $type, $sprefs );
1839                         if ( $skey ) {
1840                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1841                         }
1842                 }
1843         }
1844
1845         $bestq = 0;
1846         $besttype = null;
1847
1848         foreach ( array_keys( $combine ) as $type ) {
1849                 if ( $combine[$type] > $bestq ) {
1850                         $besttype = $type;
1851                         $bestq = $combine[$type];
1852                 }
1853         }
1854
1855         return $besttype;
1856 }
1857
1858 /**
1859  * Get a timestamp string in one of various formats
1860  *
1861  * @param mixed $outputtype A timestamp in one of the supported formats, the
1862  *   function will autodetect which format is supplied and act accordingly.
1863  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
1864  * @return string|bool String / false The same date in the format specified in $outputtype or false
1865  */
1866 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
1867         $ret = MWTimestamp::convert( $outputtype, $ts );
1868         if ( $ret === false ) {
1869                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
1870         }
1871         return $ret;
1872 }
1873
1874 /**
1875  * Return a formatted timestamp, or null if input is null.
1876  * For dealing with nullable timestamp columns in the database.
1877  *
1878  * @param int $outputtype
1879  * @param string|null $ts
1880  * @return string
1881  */
1882 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
1883         if ( is_null( $ts ) ) {
1884                 return null;
1885         } else {
1886                 return wfTimestamp( $outputtype, $ts );
1887         }
1888 }
1889
1890 /**
1891  * Convenience function; returns MediaWiki timestamp for the present time.
1892  *
1893  * @return string TS_MW timestamp
1894  */
1895 function wfTimestampNow() {
1896         return MWTimestamp::now( TS_MW );
1897 }
1898
1899 /**
1900  * Check if the operating system is Windows
1901  *
1902  * @return bool True if it's Windows, false otherwise.
1903  */
1904 function wfIsWindows() {
1905         static $isWindows = null;
1906         if ( $isWindows === null ) {
1907                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
1908         }
1909         return $isWindows;
1910 }
1911
1912 /**
1913  * Check if we are running under HHVM
1914  *
1915  * @return bool
1916  */
1917 function wfIsHHVM() {
1918         return defined( 'HHVM_VERSION' );
1919 }
1920
1921 /**
1922  * Check if we are running from the commandline
1923  *
1924  * @since 1.31
1925  * @return bool
1926  */
1927 function wfIsCLI() {
1928         return PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg';
1929 }
1930
1931 /**
1932  * Tries to get the system directory for temporary files. First
1933  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
1934  * environment variables are then checked in sequence, then
1935  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
1936  *
1937  * NOTE: When possible, use instead the tmpfile() function to create
1938  * temporary files to avoid race conditions on file creation, etc.
1939  *
1940  * @return string
1941  */
1942 function wfTempDir() {
1943         global $wgTmpDirectory;
1944
1945         if ( $wgTmpDirectory !== false ) {
1946                 return $wgTmpDirectory;
1947         }
1948
1949         return TempFSFile::getUsableTempDirectory();
1950 }
1951
1952 /**
1953  * Make directory, and make all parent directories if they don't exist
1954  *
1955  * @param string $dir Full path to directory to create
1956  * @param int|null $mode Chmod value to use, default is $wgDirectoryMode
1957  * @param string|null $caller Optional caller param for debugging.
1958  * @throws MWException
1959  * @return bool
1960  */
1961 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
1962         global $wgDirectoryMode;
1963
1964         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
1965                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
1966         }
1967
1968         if ( !is_null( $caller ) ) {
1969                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
1970         }
1971
1972         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
1973                 return true;
1974         }
1975
1976         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
1977
1978         if ( is_null( $mode ) ) {
1979                 $mode = $wgDirectoryMode;
1980         }
1981
1982         // Turn off the normal warning, we're doing our own below
1983         AtEase::suppressWarnings();
1984         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
1985         AtEase::restoreWarnings();
1986
1987         if ( !$ok ) {
1988                 // directory may have been created on another request since we last checked
1989                 if ( is_dir( $dir ) ) {
1990                         return true;
1991                 }
1992
1993                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
1994                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
1995         }
1996         return $ok;
1997 }
1998
1999 /**
2000  * Remove a directory and all its content.
2001  * Does not hide error.
2002  * @param string $dir
2003  */
2004 function wfRecursiveRemoveDir( $dir ) {
2005         wfDebug( __FUNCTION__ . "( $dir )\n" );
2006         // taken from https://www.php.net/manual/en/function.rmdir.php#98622
2007         if ( is_dir( $dir ) ) {
2008                 $objects = scandir( $dir );
2009                 foreach ( $objects as $object ) {
2010                         if ( $object != "." && $object != ".." ) {
2011                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2012                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2013                                 } else {
2014                                         unlink( $dir . '/' . $object );
2015                                 }
2016                         }
2017                 }
2018                 reset( $objects );
2019                 rmdir( $dir );
2020         }
2021 }
2022
2023 /**
2024  * @param int $nr The number to format
2025  * @param int $acc The number of digits after the decimal point, default 2
2026  * @param bool $round Whether or not to round the value, default true
2027  * @return string
2028  */
2029 function wfPercent( $nr, $acc = 2, $round = true ) {
2030         $ret = sprintf( "%.${acc}f", $nr );
2031         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2032 }
2033
2034 /**
2035  * Safety wrapper around ini_get() for boolean settings.
2036  * The values returned from ini_get() are pre-normalized for settings
2037  * set via php.ini or php_flag/php_admin_flag... but *not*
2038  * for those set via php_value/php_admin_value.
2039  *
2040  * It's fairly common for people to use php_value instead of php_flag,
2041  * which can leave you with an 'off' setting giving a false positive
2042  * for code that just takes the ini_get() return value as a boolean.
2043  *
2044  * To make things extra interesting, setting via php_value accepts
2045  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2046  * Unrecognized values go false... again opposite PHP's own coercion
2047  * from string to bool.
2048  *
2049  * Luckily, 'properly' set settings will always come back as '0' or '1',
2050  * so we only have to worry about them and the 'improper' settings.
2051  *
2052  * I frickin' hate PHP... :P
2053  *
2054  * @param string $setting
2055  * @return bool
2056  */
2057 function wfIniGetBool( $setting ) {
2058         return wfStringToBool( ini_get( $setting ) );
2059 }
2060
2061 /**
2062  * Convert string value to boolean, when the following are interpreted as true:
2063  * - on
2064  * - true
2065  * - yes
2066  * - Any number, except 0
2067  * All other strings are interpreted as false.
2068  *
2069  * @param string $val
2070  * @return bool
2071  * @since 1.31
2072  */
2073 function wfStringToBool( $val ) {
2074         $val = strtolower( $val );
2075         // 'on' and 'true' can't have whitespace around them, but '1' can.
2076         return $val == 'on'
2077                 || $val == 'true'
2078                 || $val == 'yes'
2079                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2080 }
2081
2082 /**
2083  * Version of escapeshellarg() that works better on Windows.
2084  *
2085  * Originally, this fixed the incorrect use of single quotes on Windows
2086  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2087  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2088  *
2089  * @param string|string[] ...$args strings to escape and glue together,
2090  *  or a single array of strings parameter
2091  * @return string
2092  * @deprecated since 1.30 use MediaWiki\Shell\Shell::escape()
2093  */
2094 function wfEscapeShellArg( ...$args ) {
2095         return Shell::escape( ...$args );
2096 }
2097
2098 /**
2099  * Execute a shell command, with time and memory limits mirrored from the PHP
2100  * configuration if supported.
2101  *
2102  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2103  *   or an array of unescaped arguments, in which case each value will be escaped
2104  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2105  * @param null|mixed &$retval Optional, will receive the program's exit code.
2106  *   (non-zero is usually failure). If there is an error from
2107  *   read, select, or proc_open(), this will be set to -1.
2108  * @param array $environ Optional environment variables which should be
2109  *   added to the executed command environment.
2110  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2111  *   this overwrites the global wgMaxShell* limits.
2112  * @param array $options Array of options:
2113  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2114  *     including errors from limit.sh
2115  *   - profileMethod: By default this function will profile based on the calling
2116  *     method. Set this to a string for an alternative method to profile from
2117  *
2118  * @return string Collected stdout as a string
2119  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2120  */
2121 function wfShellExec( $cmd, &$retval = null, $environ = [],
2122         $limits = [], $options = []
2123 ) {
2124         if ( Shell::isDisabled() ) {
2125                 $retval = 1;
2126                 // Backwards compatibility be upon us...
2127                 return 'Unable to run external programs, proc_open() is disabled.';
2128         }
2129
2130         if ( is_array( $cmd ) ) {
2131                 $cmd = Shell::escape( $cmd );
2132         }
2133
2134         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2135         $profileMethod = $options['profileMethod'] ?? wfGetCaller();
2136
2137         try {
2138                 $result = Shell::command( [] )
2139                         ->unsafeParams( (array)$cmd )
2140                         ->environment( $environ )
2141                         ->limits( $limits )
2142                         ->includeStderr( $includeStderr )
2143                         ->profileMethod( $profileMethod )
2144                         // For b/c
2145                         ->restrict( Shell::RESTRICT_NONE )
2146                         ->execute();
2147         } catch ( ProcOpenError $ex ) {
2148                 $retval = -1;
2149                 return '';
2150         }
2151
2152         $retval = $result->getExitCode();
2153
2154         return $result->getStdout();
2155 }
2156
2157 /**
2158  * Execute a shell command, returning both stdout and stderr. Convenience
2159  * function, as all the arguments to wfShellExec can become unwieldy.
2160  *
2161  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2162  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2163  *   or an array of unescaped arguments, in which case each value will be escaped
2164  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2165  * @param null|mixed &$retval Optional, will receive the program's exit code.
2166  *   (non-zero is usually failure)
2167  * @param array $environ Optional environment variables which should be
2168  *   added to the executed command environment.
2169  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2170  *   this overwrites the global wgMaxShell* limits.
2171  * @return string Collected stdout and stderr as a string
2172  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2173  */
2174 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2175         return wfShellExec( $cmd, $retval, $environ, $limits,
2176                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2177 }
2178
2179 /**
2180  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2181  * Note that $parameters should be a flat array and an option with an argument
2182  * should consist of two consecutive items in the array (do not use "--option value").
2183  *
2184  * @deprecated since 1.31, use Shell::makeScriptCommand()
2185  *
2186  * @param string $script MediaWiki cli script path
2187  * @param array $parameters Arguments and options to the script
2188  * @param array $options Associative array of options:
2189  *     'php': The path to the php executable
2190  *     'wrapper': Path to a PHP wrapper to handle the maintenance script
2191  * @return string
2192  */
2193 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2194         global $wgPhpCli;
2195         // Give site config file a chance to run the script in a wrapper.
2196         // The caller may likely want to call wfBasename() on $script.
2197         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2198         $cmd = [ $options['php'] ?? $wgPhpCli ];
2199         if ( isset( $options['wrapper'] ) ) {
2200                 $cmd[] = $options['wrapper'];
2201         }
2202         $cmd[] = $script;
2203         // Escape each parameter for shell
2204         return Shell::escape( array_merge( $cmd, $parameters ) );
2205 }
2206
2207 /**
2208  * wfMerge attempts to merge differences between three texts.
2209  * Returns true for a clean merge and false for failure or a conflict.
2210  *
2211  * @param string $old
2212  * @param string $mine
2213  * @param string $yours
2214  * @param string &$result
2215  * @param string|null &$mergeAttemptResult
2216  * @return bool
2217  */
2218 function wfMerge( $old, $mine, $yours, &$result, &$mergeAttemptResult = null ) {
2219         global $wgDiff3;
2220
2221         # This check may also protect against code injection in
2222         # case of broken installations.
2223         AtEase::suppressWarnings();
2224         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2225         AtEase::restoreWarnings();
2226
2227         if ( !$haveDiff3 ) {
2228                 wfDebug( "diff3 not found\n" );
2229                 return false;
2230         }
2231
2232         # Make temporary files
2233         $td = wfTempDir();
2234         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2235         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2236         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2237
2238         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2239         #       a newline character. To avoid this, we normalize the trailing whitespace before
2240         #       creating the diff.
2241
2242         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2243         fclose( $oldtextFile );
2244         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2245         fclose( $mytextFile );
2246         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2247         fclose( $yourtextFile );
2248
2249         # Check for a conflict
2250         $cmd = Shell::escape( $wgDiff3, '-a', '--overlap-only', $mytextName,
2251                 $oldtextName, $yourtextName );
2252         $handle = popen( $cmd, 'r' );
2253
2254         $mergeAttemptResult = '';
2255         do {
2256                 $data = fread( $handle, 8192 );
2257                 if ( strlen( $data ) == 0 ) {
2258                         break;
2259                 }
2260                 $mergeAttemptResult .= $data;
2261         } while ( true );
2262         pclose( $handle );
2263
2264         $conflict = $mergeAttemptResult !== '';
2265
2266         # Merge differences
2267         $cmd = Shell::escape( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2268                 $oldtextName, $yourtextName );
2269         $handle = popen( $cmd, 'r' );
2270         $result = '';
2271         do {
2272                 $data = fread( $handle, 8192 );
2273                 if ( strlen( $data ) == 0 ) {
2274                         break;
2275                 }
2276                 $result .= $data;
2277         } while ( true );
2278         pclose( $handle );
2279         unlink( $mytextName );
2280         unlink( $oldtextName );
2281         unlink( $yourtextName );
2282
2283         if ( $result === '' && $old !== '' && !$conflict ) {
2284                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2285                 $conflict = true;
2286         }
2287         return !$conflict;
2288 }
2289
2290 /**
2291  * Returns unified plain-text diff of two texts.
2292  * "Useful" for machine processing of diffs.
2293  *
2294  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2295  *
2296  * @param string $before The text before the changes.
2297  * @param string $after The text after the changes.
2298  * @param string $params Command-line options for the diff command.
2299  * @return string Unified diff of $before and $after
2300  */
2301 function wfDiff( $before, $after, $params = '-u' ) {
2302         if ( $before == $after ) {
2303                 return '';
2304         }
2305
2306         global $wgDiff;
2307         AtEase::suppressWarnings();
2308         $haveDiff = $wgDiff && file_exists( $wgDiff );
2309         AtEase::restoreWarnings();
2310
2311         # This check may also protect against code injection in
2312         # case of broken installations.
2313         if ( !$haveDiff ) {
2314                 wfDebug( "diff executable not found\n" );
2315                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2316                 $format = new UnifiedDiffFormatter();
2317                 return $format->format( $diffs );
2318         }
2319
2320         # Make temporary files
2321         $td = wfTempDir();
2322         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2323         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2324
2325         fwrite( $oldtextFile, $before );
2326         fclose( $oldtextFile );
2327         fwrite( $newtextFile, $after );
2328         fclose( $newtextFile );
2329
2330         // Get the diff of the two files
2331         $cmd = "$wgDiff " . $params . ' ' . Shell::escape( $oldtextName, $newtextName );
2332
2333         $h = popen( $cmd, 'r' );
2334         if ( !$h ) {
2335                 unlink( $oldtextName );
2336                 unlink( $newtextName );
2337                 throw new Exception( __METHOD__ . '(): popen() failed' );
2338         }
2339
2340         $diff = '';
2341
2342         do {
2343                 $data = fread( $h, 8192 );
2344                 if ( strlen( $data ) == 0 ) {
2345                         break;
2346                 }
2347                 $diff .= $data;
2348         } while ( true );
2349
2350         // Clean up
2351         pclose( $h );
2352         unlink( $oldtextName );
2353         unlink( $newtextName );
2354
2355         // Kill the --- and +++ lines. They're not useful.
2356         $diff_lines = explode( "\n", $diff );
2357         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2358                 unset( $diff_lines[0] );
2359         }
2360         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2361                 unset( $diff_lines[1] );
2362         }
2363
2364         $diff = implode( "\n", $diff_lines );
2365
2366         return $diff;
2367 }
2368
2369 /**
2370  * Return the final portion of a pathname.
2371  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2372  * https://bugs.php.net/bug.php?id=33898
2373  *
2374  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2375  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2376  *
2377  * @param string $path
2378  * @param string $suffix String to remove if present
2379  * @return string
2380  */
2381 function wfBaseName( $path, $suffix = '' ) {
2382         if ( $suffix == '' ) {
2383                 $encSuffix = '';
2384         } else {
2385                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2386         }
2387
2388         $matches = [];
2389         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2390                 return $matches[1];
2391         } else {
2392                 return '';
2393         }
2394 }
2395
2396 /**
2397  * Generate a relative path name to the given file.
2398  * May explode on non-matching case-insensitive paths,
2399  * funky symlinks, etc.
2400  *
2401  * @param string $path Absolute destination path including target filename
2402  * @param string $from Absolute source path, directory only
2403  * @return string
2404  */
2405 function wfRelativePath( $path, $from ) {
2406         // Normalize mixed input on Windows...
2407         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2408         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2409
2410         // Trim trailing slashes -- fix for drive root
2411         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2412         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2413
2414         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2415         $against = explode( DIRECTORY_SEPARATOR, $from );
2416
2417         if ( $pieces[0] !== $against[0] ) {
2418                 // Non-matching Windows drive letters?
2419                 // Return a full path.
2420                 return $path;
2421         }
2422
2423         // Trim off common prefix
2424         while ( count( $pieces ) && count( $against )
2425                 && $pieces[0] == $against[0] ) {
2426                 array_shift( $pieces );
2427                 array_shift( $against );
2428         }
2429
2430         // relative dots to bump us to the parent
2431         while ( count( $against ) ) {
2432                 array_unshift( $pieces, '..' );
2433                 array_shift( $against );
2434         }
2435
2436         array_push( $pieces, wfBaseName( $path ) );
2437
2438         return implode( DIRECTORY_SEPARATOR, $pieces );
2439 }
2440
2441 /**
2442  * Initialise php session
2443  *
2444  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2445  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2446  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2447  *  here), then calling $session->persist().
2448  * @param bool|string $sessionId
2449  */
2450 function wfSetupSession( $sessionId = false ) {
2451         wfDeprecated( __FUNCTION__, '1.27' );
2452
2453         if ( $sessionId ) {
2454                 session_id( $sessionId );
2455         }
2456
2457         $session = SessionManager::getGlobalSession();
2458         $session->persist();
2459
2460         if ( session_id() !== $session->getId() ) {
2461                 session_id( $session->getId() );
2462         }
2463         AtEase::quietCall( 'session_start' );
2464 }
2465
2466 /**
2467  * Get an object from the precompiled serialized directory
2468  *
2469  * @param string $name
2470  * @return mixed The variable on success, false on failure
2471  */
2472 function wfGetPrecompiledData( $name ) {
2473         global $IP;
2474
2475         $file = "$IP/serialized/$name";
2476         if ( file_exists( $file ) ) {
2477                 $blob = file_get_contents( $file );
2478                 if ( $blob ) {
2479                         return unserialize( $blob );
2480                 }
2481         }
2482         return false;
2483 }
2484
2485 /**
2486  * Make a cache key for the local wiki.
2487  *
2488  * @deprecated since 1.30 Call makeKey on a BagOStuff instance
2489  * @param string ...$args
2490  * @return string
2491  */
2492 function wfMemcKey( ...$args ) {
2493         return ObjectCache::getLocalClusterInstance()->makeKey( ...$args );
2494 }
2495
2496 /**
2497  * Make a cache key for a foreign DB.
2498  *
2499  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2500  *
2501  * @param string $db
2502  * @param string $prefix
2503  * @param string ...$args
2504  * @return string
2505  */
2506 function wfForeignMemcKey( $db, $prefix, ...$args ) {
2507         $keyspace = $prefix ? "$db-$prefix" : $db;
2508         return ObjectCache::getLocalClusterInstance()->makeKeyInternal( $keyspace, $args );
2509 }
2510
2511 /**
2512  * Make a cache key with database-agnostic prefix.
2513  *
2514  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
2515  * instead. Must have a prefix as otherwise keys that use a database name
2516  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
2517  *
2518  * @deprecated since 1.30 Call makeGlobalKey on a BagOStuff instance
2519  * @since 1.26
2520  * @param string ...$args
2521  * @return string
2522  */
2523 function wfGlobalCacheKey( ...$args ) {
2524         return ObjectCache::getLocalClusterInstance()->makeGlobalKey( ...$args );
2525 }
2526
2527 /**
2528  * Get an ASCII string identifying this wiki
2529  * This is used as a prefix in memcached keys
2530  *
2531  * @return string
2532  */
2533 function wfWikiID() {
2534         global $wgDBprefix, $wgDBname;
2535         if ( $wgDBprefix ) {
2536                 return "$wgDBname-$wgDBprefix";
2537         } else {
2538                 return $wgDBname;
2539         }
2540 }
2541
2542 /**
2543  * Get a Database object.
2544  *
2545  * @param int $db Index of the connection to get. May be DB_MASTER for the
2546  *            master (for write queries), DB_REPLICA for potentially lagged read
2547  *            queries, or an integer >= 0 for a particular server.
2548  *
2549  * @param string|string[] $groups Query groups. An array of group names that this query
2550  *                belongs to. May contain a single string if the query is only
2551  *                in one group.
2552  *
2553  * @param string|bool $wiki The wiki ID, or false for the current wiki
2554  *
2555  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
2556  * will always return the same object, unless the underlying connection or load
2557  * balancer is manually destroyed.
2558  *
2559  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
2560  * updater to ensure that a proper database is being updated.
2561  *
2562  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
2563  *       on an injected instance of LoadBalancer.
2564  *
2565  * @return \Wikimedia\Rdbms\Database
2566  */
2567 function wfGetDB( $db, $groups = [], $wiki = false ) {
2568         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
2569 }
2570
2571 /**
2572  * Get a load balancer object.
2573  *
2574  * @deprecated since 1.27, use MediaWikiServices::getInstance()->getDBLoadBalancer()
2575  *              or MediaWikiServices::getInstance()->getDBLoadBalancerFactory() instead.
2576  *
2577  * @param string|bool $wiki Wiki ID, or false for the current wiki
2578  * @return \Wikimedia\Rdbms\LoadBalancer
2579  */
2580 function wfGetLB( $wiki = false ) {
2581         if ( $wiki === false ) {
2582                 return MediaWikiServices::getInstance()->getDBLoadBalancer();
2583         } else {
2584                 $factory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2585                 return $factory->getMainLB( $wiki );
2586         }
2587 }
2588
2589 /**
2590  * Find a file.
2591  * @deprecated since 1.34, use MediaWikiServices
2592  * @param string|LinkTarget $title String or LinkTarget object
2593  * @param array $options Associative array of options (see RepoGroup::findFile)
2594  * @return File|bool File, or false if the file does not exist
2595  */
2596 function wfFindFile( $title, $options = [] ) {
2597         return MediaWikiServices::getInstance()->getRepoGroup()->findFile( $title, $options );
2598 }
2599
2600 /**
2601  * Get an object referring to a locally registered file.
2602  * Returns a valid placeholder object if the file does not exist.
2603  *
2604  * @deprecated since 1.34, use MediaWikiServices
2605  * @param Title|string $title
2606  * @return LocalFile|null A File, or null if passed an invalid Title
2607  */
2608 function wfLocalFile( $title ) {
2609         return MediaWikiServices::getInstance()->getRepoGroup()->getLocalRepo()->newFile( $title );
2610 }
2611
2612 /**
2613  * Should low-performance queries be disabled?
2614  *
2615  * @return bool
2616  * @codeCoverageIgnore
2617  */
2618 function wfQueriesMustScale() {
2619         global $wgMiserMode;
2620         return $wgMiserMode
2621                 || ( SiteStats::pages() > 100000
2622                 && SiteStats::edits() > 1000000
2623                 && SiteStats::users() > 10000 );
2624 }
2625
2626 /**
2627  * Get the path to a specified script file, respecting file
2628  * extensions; this is a wrapper around $wgScriptPath etc.
2629  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
2630  *
2631  * @param string $script Script filename, sans extension
2632  * @return string
2633  */
2634 function wfScript( $script = 'index' ) {
2635         global $wgScriptPath, $wgScript, $wgLoadScript;
2636         if ( $script === 'index' ) {
2637                 return $wgScript;
2638         } elseif ( $script === 'load' ) {
2639                 return $wgLoadScript;
2640         } else {
2641                 return "{$wgScriptPath}/{$script}.php";
2642         }
2643 }
2644
2645 /**
2646  * Get the script URL.
2647  *
2648  * @return string Script URL
2649  */
2650 function wfGetScriptUrl() {
2651         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
2652                 /* as it was called, minus the query string.
2653                  *
2654                  * Some sites use Apache rewrite rules to handle subdomains,
2655                  * and have PHP set up in a weird way that causes PHP_SELF
2656                  * to contain the rewritten URL instead of the one that the
2657                  * outside world sees.
2658                  *
2659                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
2660                  * provides containing the "before" URL.
2661                  */
2662                 return $_SERVER['SCRIPT_NAME'];
2663         } else {
2664                 return $_SERVER['URL'];
2665         }
2666 }
2667
2668 /**
2669  * Convenience function converts boolean values into "true"
2670  * or "false" (string) values
2671  *
2672  * @param bool $value
2673  * @return string
2674  */
2675 function wfBoolToStr( $value ) {
2676         return $value ? 'true' : 'false';
2677 }
2678
2679 /**
2680  * Get a platform-independent path to the null file, e.g. /dev/null
2681  *
2682  * @return string
2683  */
2684 function wfGetNull() {
2685         return wfIsWindows() ? 'NUL' : '/dev/null';
2686 }
2687
2688 /**
2689  * Waits for the replica DBs to catch up to the master position
2690  *
2691  * Use this when updating very large numbers of rows, as in maintenance scripts,
2692  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
2693  *
2694  * By default this waits on the main DB cluster of the current wiki.
2695  * If $cluster is set to "*" it will wait on all DB clusters, including
2696  * external ones. If the lag being waiting on is caused by the code that
2697  * does this check, it makes since to use $ifWritesSince, particularly if
2698  * cluster is "*", to avoid excess overhead.
2699  *
2700  * Never call this function after a big DB write that is still in a transaction.
2701  * This only makes sense after the possible lag inducing changes were committed.
2702  *
2703  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
2704  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
2705  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
2706  * @param int|null $timeout Max wait time. Default: 60 seconds (cli), 1 second (web)
2707  * @return bool Success (able to connect and no timeouts reached)
2708  * @deprecated since 1.27 Use LBFactory::waitForReplication
2709  */
2710 function wfWaitForSlaves(
2711         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
2712 ) {
2713         $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2714
2715         if ( $cluster === '*' ) {
2716                 $cluster = false;
2717                 $domain = false;
2718         } elseif ( $wiki === false ) {
2719                 $domain = $lbFactory->getLocalDomainID();
2720         } else {
2721                 $domain = $wiki;
2722         }
2723
2724         $opts = [
2725                 'domain' => $domain,
2726                 'cluster' => $cluster,
2727                 // B/C: first argument used to be "max seconds of lag"; ignore such values
2728                 'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
2729         ];
2730         if ( $timeout !== null ) {
2731                 $opts['timeout'] = $timeout;
2732         }
2733
2734         return $lbFactory->waitForReplication( $opts );
2735 }
2736
2737 /**
2738  * Replace all invalid characters with '-'.
2739  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
2740  * By default, $wgIllegalFileChars includes ':', '/', '\'.
2741  *
2742  * @param string $name Filename to process
2743  * @return string
2744  */
2745 function wfStripIllegalFilenameChars( $name ) {
2746         global $wgIllegalFileChars;
2747         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
2748         $name = preg_replace(
2749                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
2750                 '-',
2751                 $name
2752         );
2753         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
2754         $name = wfBaseName( $name );
2755         return $name;
2756 }
2757
2758 /**
2759  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
2760  *
2761  * @return int Resulting value of the memory limit.
2762  */
2763 function wfMemoryLimit() {
2764         global $wgMemoryLimit;
2765         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
2766         if ( $memlimit != -1 ) {
2767                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
2768                 if ( $conflimit == -1 ) {
2769                         wfDebug( "Removing PHP's memory limit\n" );
2770                         Wikimedia\suppressWarnings();
2771                         ini_set( 'memory_limit', $conflimit );
2772                         Wikimedia\restoreWarnings();
2773                         return $conflimit;
2774                 } elseif ( $conflimit > $memlimit ) {
2775                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
2776                         Wikimedia\suppressWarnings();
2777                         ini_set( 'memory_limit', $conflimit );
2778                         Wikimedia\restoreWarnings();
2779                         return $conflimit;
2780                 }
2781         }
2782         return $memlimit;
2783 }
2784
2785 /**
2786  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
2787  *
2788  * @return int Prior time limit
2789  * @since 1.26
2790  */
2791 function wfTransactionalTimeLimit() {
2792         global $wgTransactionalTimeLimit;
2793
2794         $timeLimit = ini_get( 'max_execution_time' );
2795         // Note that CLI scripts use 0
2796         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
2797                 set_time_limit( $wgTransactionalTimeLimit );
2798         }
2799
2800         ignore_user_abort( true ); // ignore client disconnects
2801
2802         return $timeLimit;
2803 }
2804
2805 /**
2806  * Converts shorthand byte notation to integer form
2807  *
2808  * @param string $string
2809  * @param int $default Returned if $string is empty
2810  * @return int
2811  */
2812 function wfShorthandToInteger( $string = '', $default = -1 ) {
2813         $string = trim( $string );
2814         if ( $string === '' ) {
2815                 return $default;
2816         }
2817         $last = $string[strlen( $string ) - 1];
2818         $val = intval( $string );
2819         switch ( $last ) {
2820                 case 'g':
2821                 case 'G':
2822                         $val *= 1024;
2823                         // break intentionally missing
2824                 case 'm':
2825                 case 'M':
2826                         $val *= 1024;
2827                         // break intentionally missing
2828                 case 'k':
2829                 case 'K':
2830                         $val *= 1024;
2831         }
2832
2833         return $val;
2834 }
2835
2836 /**
2837  * Get a specific cache object.
2838  *
2839  * @deprecated since 1.32, use ObjectCache::getInstance() instead
2840  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
2841  * @return BagOStuff
2842  */
2843 function wfGetCache( $cacheType ) {
2844         return ObjectCache::getInstance( $cacheType );
2845 }
2846
2847 /**
2848  * Get the main cache object
2849  *
2850  * @deprecated since 1.32, use ObjectCache::getLocalClusterInstance() instead
2851  * @return BagOStuff
2852  */
2853 function wfGetMainCache() {
2854         return ObjectCache::getLocalClusterInstance();
2855 }
2856
2857 /**
2858  * Get the cache object used by the message cache
2859  *
2860  * @return BagOStuff
2861  */
2862 function wfGetMessageCacheStorage() {
2863         global $wgMessageCacheType;
2864         return ObjectCache::getInstance( $wgMessageCacheType );
2865 }
2866
2867 /**
2868  * Wrapper around php's unpack.
2869  *
2870  * @param string $format The format string (See php's docs)
2871  * @param string $data A binary string of binary data
2872  * @param int|bool $length The minimum length of $data or false. This is to
2873  *      prevent reading beyond the end of $data. false to disable the check.
2874  *
2875  * Also be careful when using this function to read unsigned 32 bit integer
2876  * because php might make it negative.
2877  *
2878  * @throws MWException If $data not long enough, or if unpack fails
2879  * @return array Associative array of the extracted data
2880  */
2881 function wfUnpack( $format, $data, $length = false ) {
2882         if ( $length !== false ) {
2883                 $realLen = strlen( $data );
2884                 if ( $realLen < $length ) {
2885                         throw new MWException( "Tried to use wfUnpack on a "
2886                                 . "string of length $realLen, but needed one "
2887                                 . "of at least length $length."
2888                         );
2889                 }
2890         }
2891
2892         Wikimedia\suppressWarnings();
2893         $result = unpack( $format, $data );
2894         Wikimedia\restoreWarnings();
2895
2896         if ( $result === false ) {
2897                 // If it cannot extract the packed data.
2898                 throw new MWException( "unpack could not unpack binary data" );
2899         }
2900         return $result;
2901 }
2902
2903 /**
2904  * Determine if an image exists on the 'bad image list'.
2905  *
2906  * The format of MediaWiki:Bad_image_list is as follows:
2907  *    * Only list items (lines starting with "*") are considered
2908  *    * The first link on a line must be a link to a bad image
2909  *    * Any subsequent links on the same line are considered to be exceptions,
2910  *      i.e. articles where the image may occur inline.
2911  *
2912  * @param string $name The image name to check
2913  * @param Title|bool $contextTitle The page on which the image occurs, if known
2914  * @param string|null $blacklist Wikitext of a file blacklist
2915  * @return bool
2916  */
2917 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
2918         # Handle redirects; callers almost always hit wfFindFile() anyway,
2919         # so just use that method because it has a fast process cache.
2920         $file = MediaWikiServices::getInstance()->getRepoGroup()->findFile( $name ); // get the final name
2921         $name = $file ? $file->getTitle()->getDBkey() : $name;
2922
2923         # Run the extension hook
2924         $bad = false;
2925         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
2926                 return (bool)$bad;
2927         }
2928
2929         $cache = ObjectCache::getLocalServerInstance( 'hash' );
2930         $key = $cache->makeKey(
2931                 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist )
2932         );
2933         $badImages = $cache->get( $key );
2934
2935         if ( $badImages === false ) { // cache miss
2936                 if ( $blacklist === null ) {
2937                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
2938                 }
2939                 # Build the list now
2940                 $badImages = [];
2941                 $lines = explode( "\n", $blacklist );
2942                 foreach ( $lines as $line ) {
2943                         # List items only
2944                         if ( substr( $line, 0, 1 ) !== '*' ) {
2945                                 continue;
2946                         }
2947
2948                         # Find all links
2949                         $m = [];
2950                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
2951                                 continue;
2952                         }
2953
2954                         $exceptions = [];
2955                         $imageDBkey = false;
2956                         foreach ( $m[1] as $i => $titleText ) {
2957                                 $title = Title::newFromText( $titleText );
2958                                 if ( !is_null( $title ) ) {
2959                                         if ( $i == 0 ) {
2960                                                 $imageDBkey = $title->getDBkey();
2961                                         } else {
2962                                                 $exceptions[$title->getPrefixedDBkey()] = true;
2963                                         }
2964                                 }
2965                         }
2966
2967                         if ( $imageDBkey !== false ) {
2968                                 $badImages[$imageDBkey] = $exceptions;
2969                         }
2970                 }
2971                 $cache->set( $key, $badImages, 60 );
2972         }
2973
2974         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
2975         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
2976
2977         return $bad;
2978 }
2979
2980 /**
2981  * Determine whether the client at a given source IP is likely to be able to
2982  * access the wiki via HTTPS.
2983  *
2984  * @param string $ip The IPv4/6 address in the normal human-readable form
2985  * @return bool
2986  */
2987 function wfCanIPUseHTTPS( $ip ) {
2988         $canDo = true;
2989         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
2990         return (bool)$canDo;
2991 }
2992
2993 /**
2994  * Determine input string is represents as infinity
2995  *
2996  * @param string $str The string to determine
2997  * @return bool
2998  * @since 1.25
2999  */
3000 function wfIsInfinity( $str ) {
3001         // These are hardcoded elsewhere in MediaWiki (e.g. mediawiki.special.block.js).
3002         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3003         return in_array( $str, $infinityValues );
3004 }
3005
3006 /**
3007  * Returns true if these thumbnail parameters match one that MediaWiki
3008  * requests from file description pages and/or parser output.
3009  *
3010  * $params is considered non-standard if they involve a non-standard
3011  * width or any non-default parameters aside from width and page number.
3012  * The number of possible files with standard parameters is far less than
3013  * that of all combinations; rate-limiting for them can thus be more generious.
3014  *
3015  * @param File $file
3016  * @param array $params
3017  * @return bool
3018  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3019  */
3020 function wfThumbIsStandard( File $file, array $params ) {
3021         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3022
3023         $multipliers = [ 1 ];
3024         if ( $wgResponsiveImages ) {
3025                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3026                 // @see Linker::processResponsiveImages
3027                 $multipliers[] = 1.5;
3028                 $multipliers[] = 2;
3029         }
3030
3031         $handler = $file->getHandler();
3032         if ( !$handler || !isset( $params['width'] ) ) {
3033                 return false;
3034         }
3035
3036         $basicParams = [];
3037         if ( isset( $params['page'] ) ) {
3038                 $basicParams['page'] = $params['page'];
3039         }
3040
3041         $thumbLimits = [];
3042         $imageLimits = [];
3043         // Expand limits to account for multipliers
3044         foreach ( $multipliers as $multiplier ) {
3045                 $thumbLimits = array_merge( $thumbLimits, array_map(
3046                         function ( $width ) use ( $multiplier ) {
3047                                 return round( $width * $multiplier );
3048                         }, $wgThumbLimits )
3049                 );
3050                 $imageLimits = array_merge( $imageLimits, array_map(
3051                         function ( $pair ) use ( $multiplier ) {
3052                                 return [
3053                                         round( $pair[0] * $multiplier ),
3054                                         round( $pair[1] * $multiplier ),
3055                                 ];
3056                         }, $wgImageLimits )
3057                 );
3058         }
3059
3060         // Check if the width matches one of $wgThumbLimits
3061         if ( in_array( $params['width'], $thumbLimits ) ) {
3062                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3063                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3064                 $handler->normaliseParams( $file, $normalParams );
3065         } else {
3066                 // If not, then check if the width matchs one of $wgImageLimits
3067                 $match = false;
3068                 foreach ( $imageLimits as $pair ) {
3069                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3070                         // Decide whether the thumbnail should be scaled on width or height.
3071                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3072                         $handler->normaliseParams( $file, $normalParams );
3073                         // Check if this standard thumbnail size maps to the given width
3074                         if ( $normalParams['width'] == $params['width'] ) {
3075                                 $match = true;
3076                                 break;
3077                         }
3078                 }
3079                 if ( !$match ) {
3080                         return false; // not standard for description pages
3081                 }
3082         }
3083
3084         // Check that the given values for non-page, non-width, params are just defaults
3085         foreach ( $params as $key => $value ) {
3086                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3087                         return false;
3088                 }
3089         }
3090
3091         return true;
3092 }
3093
3094 /**
3095  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3096  *
3097  * Values that exist in both values will be combined with += (all values of the array
3098  * of $newValues will be added to the values of the array of $baseArray, while values,
3099  * that exists in both, the value of $baseArray will be used).
3100  *
3101  * @param array $baseArray The array where you want to add the values of $newValues to
3102  * @param array $newValues An array with new values
3103  * @return array The combined array
3104  * @since 1.26
3105  */
3106 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3107         // First merge items that are in both arrays
3108         foreach ( $baseArray as $name => &$groupVal ) {
3109                 if ( isset( $newValues[$name] ) ) {
3110                         $groupVal += $newValues[$name];
3111                 }
3112         }
3113         // Now add items that didn't exist yet
3114         $baseArray += $newValues;
3115
3116         return $baseArray;
3117 }
3118
3119 /**
3120  * Get system resource usage of current request context.
3121  * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
3122  * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
3123  *
3124  * @since 1.24
3125  * @return array|bool Resource usage data or false if no data available.
3126  */
3127 function wfGetRusage() {
3128         if ( !function_exists( 'getrusage' ) ) {
3129                 return false;
3130         } elseif ( defined( 'HHVM_VERSION' ) && PHP_OS === 'Linux' ) {
3131                 return getrusage( 2 /* RUSAGE_THREAD */ );
3132         } else {
3133                 return getrusage( 0 /* RUSAGE_SELF */ );
3134         }
3135 }