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\ScopedCallback;
  34 use Wikimedia\WrappedString;
  35 use Wikimedia\AtEase\AtEase;
  36
  37 /**
  38  * Load an extension
  39  *
  40  * This queues an extension to be loaded through
  41  * the ExtensionRegistry system.
  42  *
  43  * @param string $ext Name of the extension to load
  44  * @param string|null $path Absolute path of where to find the extension.json file
  45  * @since 1.25
  46  */
  47 function wfLoadExtension( $ext, $path = null ) {
  48         if ( !$path ) {
  49                 global $wgExtensionDirectory;
  50                 $path = "$wgExtensionDirectory/$ext/extension.json";
  51         }
  52         ExtensionRegistry::getInstance()->queue( $path );
  53 }
  54
  55 /**
  56  * Load multiple extensions at once
  57  *
  58  * Same as wfLoadExtension, but more efficient if you
  59  * are loading multiple extensions.
  60  *
  61  * If you want to specify custom paths, you should interact with
  62  * ExtensionRegistry directly.
  63  *
  64  * @see wfLoadExtension
  65  * @param string[] $exts Array of extension names to load
  66  * @since 1.25
  67  */
  68 function wfLoadExtensions( array $exts ) {
  69         global $wgExtensionDirectory;
  70         $registry = ExtensionRegistry::getInstance();
  71         foreach ( $exts as $ext ) {
  72                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
  73         }
  74 }
  75
  76 /**
  77  * Load a skin
  78  *
  79  * @see wfLoadExtension
  80  * @param string $skin Name of the extension to load
  81  * @param string|null $path Absolute path of where to find the skin.json file
  82  * @since 1.25
  83  */
  84 function wfLoadSkin( $skin, $path = null ) {
  85         if ( !$path ) {
  86                 global $wgStyleDirectory;
  87                 $path = "$wgStyleDirectory/$skin/skin.json";
  88         }
  89         ExtensionRegistry::getInstance()->queue( $path );
  90 }
  91
  92 /**
  93  * Load multiple skins at once
  94  *
  95  * @see wfLoadExtensions
  96  * @param string[] $skins Array of extension names to load
  97  * @since 1.25
  98  */
  99 function wfLoadSkins( array $skins ) {
 100         global $wgStyleDirectory;
 101         $registry = ExtensionRegistry::getInstance();
 102         foreach ( $skins as $skin ) {
 103                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 104         }
 105 }
 106
 107 /**
 108  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 109  * @param array $a
 110  * @param array $b
 111  * @return array
 112  */
 113 function wfArrayDiff2( $a, $b ) {
 114         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 115 }
 116
 117 /**
 118  * @param array|string $a
 119  * @param array|string $b
 120  * @return int
 121  */
 122 function wfArrayDiff2_cmp( $a, $b ) {
 123         if ( is_string( $a ) && is_string( $b ) ) {
 124                 return strcmp( $a, $b );
 125         } elseif ( count( $a ) !== count( $b ) ) {
 126                 return count( $a ) <=> count( $b );
 127         } else {
 128                 reset( $a );
 129                 reset( $b );
 130                 while ( key( $a ) !== null && key( $b ) !== null ) {
 131                         $valueA = current( $a );
 132                         $valueB = current( $b );
 133                         $cmp = strcmp( $valueA, $valueB );
 134                         if ( $cmp !== 0 ) {
 135                                 return $cmp;
 136                         }
 137                         next( $a );
 138                         next( $b );
 139                 }
 140                 return 0;
 141         }
 142 }
 143
 144 /**
 145  * Appends to second array if $value differs from that in $default
 146  *
 147  * @param string|int $key
 148  * @param mixed $value
 149  * @param mixed $default
 150  * @param array &$changed Array to alter
 151  * @throws MWException
 152  */
 153 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 154         if ( is_null( $changed ) ) {
 155                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 156         }
 157         if ( $default[$key] !== $value ) {
 158                 $changed[$key] = $value;
 159         }
 160 }
 161
 162 /**
 163  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 164  * e.g.
 165  *     wfMergeErrorArrays(
 166  *       [ [ 'x' ] ],
 167  *       [ [ 'x', '2' ] ],
 168  *       [ [ 'x' ] ],
 169  *       [ [ 'y' ] ]
 170  *     );
 171  * returns:
 172  *     [
 173  *       [ 'x', '2' ],
 174  *       [ 'x' ],
 175  *       [ 'y' ]
 176  *     ]
 177  *
 178  * @param array ...$args
 179  * @return array
 180  */
 181 function wfMergeErrorArrays( ...$args ) {
 182         $out = [];
 183         foreach ( $args as $errors ) {
 184                 foreach ( $errors as $params ) {
 185                         $originalParams = $params;
 186                         if ( $params[0] instanceof MessageSpecifier ) {
 187                                 $msg = $params[0];
 188                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 189                         }
 190                         # @todo FIXME: Sometimes get nested arrays for $params,
 191                         # which leads to E_NOTICEs
 192                         $spec = implode( "\t", $params );
 193                         $out[$spec] = $originalParams;
 194                 }
 195         }
 196         return array_values( $out );
 197 }
 198
 199 /**
 200  * Insert array into another array after the specified *KEY*
 201  *
 202  * @param array $array The array.
 203  * @param array $insert The array to insert.
 204  * @param mixed $after The key to insert after. Callers need to make sure the key is set.
 205  * @return array
 206  */
 207 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 208         // Find the offset of the element to insert after.
 209         $keys = array_keys( $array );
 210         $offsetByKey = array_flip( $keys );
 211
 212         $offset = $offsetByKey[$after];
 213
 214         // Insert at the specified offset
 215         $before = array_slice( $array, 0, $offset + 1, true );
 216         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 217
 218         $output = $before + $insert + $after;
 219
 220         return $output;
 221 }
 222
 223 /**
 224  * Recursively converts the parameter (an object) to an array with the same data
 225  *
 226  * @param object|array $objOrArray
 227  * @param bool $recursive
 228  * @return array
 229  */
 230 function wfObjectToArray( $objOrArray, $recursive = true ) {
 231         $array = [];
 232         if ( is_object( $objOrArray ) ) {
 233                 $objOrArray = get_object_vars( $objOrArray );
 234         }
 235         foreach ( $objOrArray as $key => $value ) {
 236                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 237                         $value = wfObjectToArray( $value );
 238                 }
 239
 240                 $array[$key] = $value;
 241         }
 242
 243         return $array;
 244 }
 245
 246 /**
 247  * Get a random decimal value in the domain of [0, 1), in a way
 248  * not likely to give duplicate values for any realistic
 249  * number of articles.
 250  *
 251  * @note This is designed for use in relation to Special:RandomPage
 252  *       and the page_random database field.
 253  *
 254  * @return string
 255  */
 256 function wfRandom() {
 257         // The maximum random value is "only" 2^31-1, so get two random
 258         // values to reduce the chance of dupes
 259         $max = mt_getrandmax() + 1;
 260         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 261         return $rand;
 262 }
 263
 264 /**
 265  * Get a random string containing a number of pseudo-random hex characters.
 266  *
 267  * @note This is not secure, if you are trying to generate some sort
 268  *       of token please use MWCryptRand instead.
 269  *
 270  * @param int $length The length of the string to generate
 271  * @return string
 272  * @since 1.20
 273  */
 274 function wfRandomString( $length = 32 ) {
 275         $str = '';
 276         for ( $n = 0; $n < $length; $n += 7 ) {
 277                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 278         }
 279         return substr( $str, 0, $length );
 280 }
 281
 282 /**
 283  * We want some things to be included as literal characters in our title URLs
 284  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 285  * all of the following should be safe:
 286  *
 287  * ;:@&=$-_.+!*'(),
 288  *
 289  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 290  * character which should not be encoded. More importantly, google chrome
 291  * always converts %7E back to ~, and converting it in this function can
 292  * cause a redirect loop (T105265).
 293  *
 294  * But + is not safe because it's used to indicate a space; &= are only safe in
 295  * paths and not in queries (and we don't distinguish here); ' seems kind of
 296  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 297  * is reserved, we don't care.  So the list we unescape is:
 298  *
 299  * ;:@$!*(),/~
 300  *
 301  * However, IIS7 redirects fail when the url contains a colon (see T24709),
 302  * so no fancy : for IIS7.
 303  *
 304  * %2F in the page titles seems to fatally break for some reason.
 305  *
 306  * @param string $s
 307  * @return string
 308  */
 309 function wfUrlencode( $s ) {
 310         static $needle;
 311
 312         if ( is_null( $s ) ) {
 313                 // Reset $needle for testing.
 314                 $needle = null;
 315                 return '';
 316         }
 317
 318         if ( is_null( $needle ) ) {
 319                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 320                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 321                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 322                 ) {
 323                         $needle[] = '%3A';
 324                 }
 325         }
 326
 327         $s = urlencode( $s );
 328         $s = str_ireplace(
 329                 $needle,
 330                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 331                 $s
 332         );
 333
 334         return $s;
 335 }
 336
 337 /**
 338  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 339  * "days=7&limit=100". Options in the first array override options in the second.
 340  * Options set to null or false will not be output.
 341  *
 342  * @param array $array1 ( String|Array )
 343  * @param array|null $array2 ( String|Array )
 344  * @param string $prefix
 345  * @return string
 346  */
 347 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 348         if ( !is_null( $array2 ) ) {
 349                 $array1 = $array1 + $array2;
 350         }
 351
 352         $cgi = '';
 353         foreach ( $array1 as $key => $value ) {
 354                 if ( !is_null( $value ) && $value !== false ) {
 355                         if ( $cgi != '' ) {
 356                                 $cgi .= '&';
 357                         }
 358                         if ( $prefix !== '' ) {
 359                                 $key = $prefix . "[$key]";
 360                         }
 361                         if ( is_array( $value ) ) {
 362                                 $firstTime = true;
 363                                 foreach ( $value as $k => $v ) {
 364                                         $cgi .= $firstTime ? '' : '&';
 365                                         if ( is_array( $v ) ) {
 366                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 367                                         } else {
 368                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 369                                         }
 370                                         $firstTime = false;
 371                                 }
 372                         } else {
 373                                 if ( is_object( $value ) ) {
 374                                         $value = $value->__toString();
 375                                 }
 376                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 377                         }
 378                 }
 379         }
 380         return $cgi;
 381 }
 382
 383 /**
 384  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 385  * its argument and returns the same string in array form.  This allows compatibility
 386  * with legacy functions that accept raw query strings instead of nice
 387  * arrays.  Of course, keys and values are urldecode()d.
 388  *
 389  * @param string $query Query string
 390  * @return string[] Array version of input
 391  */
 392 function wfCgiToArray( $query ) {
 393         if ( isset( $query[0] ) && $query[0] == '?' ) {
 394                 $query = substr( $query, 1 );
 395         }
 396         $bits = explode( '&', $query );
 397         $ret = [];
 398         foreach ( $bits as $bit ) {
 399                 if ( $bit === '' ) {
 400                         continue;
 401                 }
 402                 if ( strpos( $bit, '=' ) === false ) {
 403                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 404                         $key = $bit;
 405                         $value = '';
 406                 } else {
 407                         list( $key, $value ) = explode( '=', $bit );
 408                 }
 409                 $key = urldecode( $key );
 410                 $value = urldecode( $value );
 411                 if ( strpos( $key, '[' ) !== false ) {
 412                         $keys = array_reverse( explode( '[', $key ) );
 413                         $key = array_pop( $keys );
 414                         $temp = $value;
 415                         foreach ( $keys as $k ) {
 416                                 $k = substr( $k, 0, -1 );
 417                                 $temp = [ $k => $temp ];
 418                         }
 419                         if ( isset( $ret[$key] ) ) {
 420                                 $ret[$key] = array_merge( $ret[$key], $temp );
 421                         } else {
 422                                 $ret[$key] = $temp;
 423                         }
 424                 } else {
 425                         $ret[$key] = $value;
 426                 }
 427         }
 428         return $ret;
 429 }
 430
 431 /**
 432  * Append a query string to an existing URL, which may or may not already
 433  * have query string parameters already. If so, they will be combined.
 434  *
 435  * @param string $url
 436  * @param string|string[] $query String or associative array
 437  * @return string
 438  */
 439 function wfAppendQuery( $url, $query ) {
 440         if ( is_array( $query ) ) {
 441                 $query = wfArrayToCgi( $query );
 442         }
 443         if ( $query != '' ) {
 444                 // Remove the fragment, if there is one
 445                 $fragment = false;
 446                 $hashPos = strpos( $url, '#' );
 447                 if ( $hashPos !== false ) {
 448                         $fragment = substr( $url, $hashPos );
 449                         $url = substr( $url, 0, $hashPos );
 450                 }
 451
 452                 // Add parameter
 453                 if ( strpos( $url, '?' ) === false ) {
 454                         $url .= '?';
 455                 } else {
 456                         $url .= '&';
 457                 }
 458                 $url .= $query;
 459
 460                 // Put the fragment back
 461                 if ( $fragment !== false ) {
 462                         $url .= $fragment;
 463                 }
 464         }
 465         return $url;
 466 }
 467
 468 /**
 469  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 470  * is correct.
 471  *
 472  * The meaning of the PROTO_* constants is as follows:
 473  * PROTO_HTTP: Output a URL starting with http://
 474  * PROTO_HTTPS: Output a URL starting with https://
 475  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 476  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 477  *    on which protocol was used for the current incoming request
 478  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 479  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 480  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 481  *
 482  * @todo this won't work with current-path-relative URLs
 483  * like "subdir/foo.html", etc.
 484  *
 485  * @param string $url Either fully-qualified or a local path + query
 486  * @param string|int|null $defaultProto One of the PROTO_* constants. Determines the
 487  *    protocol to use if $url or $wgServer is protocol-relative
 488  * @return string|false Fully-qualified URL, current-path-relative URL or false if
 489  *    no valid URL can be constructed
 490  */
 491 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 492         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 493                 $wgHttpsPort;
 494         if ( $defaultProto === PROTO_CANONICAL ) {
 495                 $serverUrl = $wgCanonicalServer;
 496         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 497                 // Make $wgInternalServer fall back to $wgServer if not set
 498                 $serverUrl = $wgInternalServer;
 499         } else {
 500                 $serverUrl = $wgServer;
 501                 if ( $defaultProto === PROTO_CURRENT ) {
 502                         $defaultProto = $wgRequest->getProtocol() . '://';
 503                 }
 504         }
 505
 506         // Analyze $serverUrl to obtain its protocol
 507         $bits = wfParseUrl( $serverUrl );
 508         $serverHasProto = $bits && $bits['scheme'] != '';
 509
 510         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 511                 if ( $serverHasProto ) {
 512                         $defaultProto = $bits['scheme'] . '://';
 513                 } else {
 514                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 515                         // This really isn't supposed to happen. Fall back to HTTP in this
 516                         // ridiculous case.
 517                         $defaultProto = PROTO_HTTP;
 518                 }
 519         }
 520
 521         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 522
 523         if ( substr( $url, 0, 2 ) == '//' ) {
 524                 $url = $defaultProtoWithoutSlashes . $url;
 525         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 526                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 527                 // otherwise leave it alone.
 528                 if ( $serverHasProto ) {
 529                         $url = $serverUrl . $url;
 530                 } else {
 531                         // If an HTTPS URL is synthesized from a protocol-relative $wgServer, allow the
 532                         // user to override the port number (T67184)
 533                         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 534                                 if ( isset( $bits['port'] ) ) {
 535                                         throw new Exception( 'A protocol-relative $wgServer may not contain a port number' );
 536                                 }
 537                                 $url = $defaultProtoWithoutSlashes . $serverUrl . ':' . $wgHttpsPort . $url;
 538                         } else {
 539                                 $url = $defaultProtoWithoutSlashes . $serverUrl . $url;
 540                         }
 541                 }
 542         }
 543
 544         $bits = wfParseUrl( $url );
 545
 546         if ( $bits && isset( $bits['path'] ) ) {
 547                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 548                 return wfAssembleUrl( $bits );
 549         } elseif ( $bits ) {
 550                 # No path to expand
 551                 return $url;
 552         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 553                 # URL is a relative path
 554                 return wfRemoveDotSegments( $url );
 555         }
 556
 557         # Expanded URL is not valid.
 558         return false;
 559 }
 560
 561 /**
 562  * Get the wiki's "server", i.e. the protocol and host part of the URL, with a
 563  * protocol specified using a PROTO_* constant as in wfExpandUrl()
 564  *
 565  * @since 1.32
 566  * @param string|int|null $proto One of the PROTO_* constants.
 567  * @return string The URL
 568  */
 569 function wfGetServerUrl( $proto ) {
 570         $url = wfExpandUrl( '/', $proto );
 571         return substr( $url, 0, -1 );
 572 }
 573
 574 /**
 575  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 576  * if you need to edit part of a URL and put it back together.
 577  *
 578  * This is the basic structure used (brackets contain keys for $urlParts):
 579  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 580  *
 581  * @todo Need to integrate this into wfExpandUrl (see T34168)
 582  *
 583  * @since 1.19
 584  * @param array $urlParts URL parts, as output from wfParseUrl
 585  * @return string URL assembled from its component parts
 586  */
 587 function wfAssembleUrl( $urlParts ) {
 588         $result = '';
 589
 590         if ( isset( $urlParts['delimiter'] ) ) {
 591                 if ( isset( $urlParts['scheme'] ) ) {
 592                         $result .= $urlParts['scheme'];
 593                 }
 594
 595                 $result .= $urlParts['delimiter'];
 596         }
 597
 598         if ( isset( $urlParts['host'] ) ) {
 599                 if ( isset( $urlParts['user'] ) ) {
 600                         $result .= $urlParts['user'];
 601                         if ( isset( $urlParts['pass'] ) ) {
 602                                 $result .= ':' . $urlParts['pass'];
 603                         }
 604                         $result .= '@';
 605                 }
 606
 607                 $result .= $urlParts['host'];
 608
 609                 if ( isset( $urlParts['port'] ) ) {
 610                         $result .= ':' . $urlParts['port'];
 611                 }
 612         }
 613
 614         if ( isset( $urlParts['path'] ) ) {
 615                 $result .= $urlParts['path'];
 616         }
 617
 618         if ( isset( $urlParts['query'] ) ) {
 619                 $result .= '?' . $urlParts['query'];
 620         }
 621
 622         if ( isset( $urlParts['fragment'] ) ) {
 623                 $result .= '#' . $urlParts['fragment'];
 624         }
 625
 626         return $result;
 627 }
 628
 629 /**
 630  * Remove all dot-segments in the provided URL path.  For example,
 631  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 632  * RFC3986 section 5.2.4.
 633  *
 634  * @todo Need to integrate this into wfExpandUrl (see T34168)
 635  *
 636  * @since 1.19
 637  *
 638  * @param string $urlPath URL path, potentially containing dot-segments
 639  * @return string URL path with all dot-segments removed
 640  */
 641 function wfRemoveDotSegments( $urlPath ) {
 642         $output = '';
 643         $inputOffset = 0;
 644         $inputLength = strlen( $urlPath );
 645
 646         while ( $inputOffset < $inputLength ) {
 647                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 648                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 649                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 650                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 651                 $trimOutput = false;
 652
 653                 if ( $prefixLengthTwo == './' ) {
 654                         # Step A, remove leading "./"
 655                         $inputOffset += 2;
 656                 } elseif ( $prefixLengthThree == '../' ) {
 657                         # Step A, remove leading "../"
 658                         $inputOffset += 3;
 659                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 660                         # Step B, replace leading "/.$" with "/"
 661                         $inputOffset += 1;
 662                         $urlPath[$inputOffset] = '/';
 663                 } elseif ( $prefixLengthThree == '/./' ) {
 664                         # Step B, replace leading "/./" with "/"
 665                         $inputOffset += 2;
 666                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 667                         # Step C, replace leading "/..$" with "/" and
 668                         # remove last path component in output
 669                         $inputOffset += 2;
 670                         $urlPath[$inputOffset] = '/';
 671                         $trimOutput = true;
 672                 } elseif ( $prefixLengthFour == '/../' ) {
 673                         # Step C, replace leading "/../" with "/" and
 674                         # remove last path component in output
 675                         $inputOffset += 3;
 676                         $trimOutput = true;
 677                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 678                         # Step D, remove "^.$"
 679                         $inputOffset += 1;
 680                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 681                         # Step D, remove "^..$"
 682                         $inputOffset += 2;
 683                 } else {
 684                         # Step E, move leading path segment to output
 685                         if ( $prefixLengthOne == '/' ) {
 686                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 687                         } else {
 688                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 689                         }
 690                         if ( $slashPos === false ) {
 691                                 $output .= substr( $urlPath, $inputOffset );
 692                                 $inputOffset = $inputLength;
 693                         } else {
 694                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 695                                 $inputOffset += $slashPos - $inputOffset;
 696                         }
 697                 }
 698
 699                 if ( $trimOutput ) {
 700                         $slashPos = strrpos( $output, '/' );
 701                         if ( $slashPos === false ) {
 702                                 $output = '';
 703                         } else {
 704                                 $output = substr( $output, 0, $slashPos );
 705                         }
 706                 }
 707         }
 708
 709         return $output;
 710 }
 711
 712 /**
 713  * Returns a regular expression of url protocols
 714  *
 715  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 716  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 717  * @return string
 718  */
 719 function wfUrlProtocols( $includeProtocolRelative = true ) {
 720         global $wgUrlProtocols;
 721
 722         // Cache return values separately based on $includeProtocolRelative
 723         static $withProtRel = null, $withoutProtRel = null;
 724         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 725         if ( !is_null( $cachedValue ) ) {
 726                 return $cachedValue;
 727         }
 728
 729         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 730         // with LocalSettings files from 1.5
 731         if ( is_array( $wgUrlProtocols ) ) {
 732                 $protocols = [];
 733                 foreach ( $wgUrlProtocols as $protocol ) {
 734                         // Filter out '//' if !$includeProtocolRelative
 735                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 736                                 $protocols[] = preg_quote( $protocol, '/' );
 737                         }
 738                 }
 739
 740                 $retval = implode( '|', $protocols );
 741         } else {
 742                 // Ignore $includeProtocolRelative in this case
 743                 // This case exists for pre-1.6 compatibility, and we can safely assume
 744                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 745                 // URLs weren't supported until 1.18
 746                 $retval = $wgUrlProtocols;
 747         }
 748
 749         // Cache return value
 750         if ( $includeProtocolRelative ) {
 751                 $withProtRel = $retval;
 752         } else {
 753                 $withoutProtRel = $retval;
 754         }
 755         return $retval;
 756 }
 757
 758 /**
 759  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 760  * you need a regex that matches all URL protocols but does not match protocol-
 761  * relative URLs
 762  * @return string
 763  */
 764 function wfUrlProtocolsWithoutProtRel() {
 765         return wfUrlProtocols( false );
 766 }
 767
 768 /**
 769  * parse_url() work-alike, but non-broken.  Differences:
 770  *
 771  * 1) Does not raise warnings on bad URLs (just returns false).
 772  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 773  *    protocol-relative URLs) correctly.
 774  * 3) Adds a "delimiter" element to the array (see (2)).
 775  * 4) Verifies that the protocol is on the $wgUrlProtocols whitelist.
 776  * 5) Rejects some invalid URLs that parse_url doesn't, e.g. the empty string or URLs starting with
 777  *    a line feed character.
 778  *
 779  * @param string $url A URL to parse
 780  * @return string[]|bool Bits of the URL in an associative array, or false on failure.
 781  *   Possible fields:
 782  *   - scheme: URI scheme (protocol), e.g. 'http', 'mailto'. Lowercase, always present, but can
 783  *       be an empty string for protocol-relative URLs.
 784  *   - delimiter: either '://', ':' or '//'. Always present.
 785  *   - host: domain name / IP. Always present, but could be an empty string, e.g. for file: URLs.
 786  *   - user: user name, e.g. for HTTP Basic auth URLs such as http://user:pass@example.com/
 787  *       Missing when there is no username.
 788  *   - pass: password, same as above.
 789  *   - path: path including the leading /. Will be missing when empty (e.g. 'http://example.com')
 790  *   - query: query string (as a string; see wfCgiToArray() for parsing it), can be missing.
 791  *   - fragment: the part after #, can be missing.
 792  */
 793 function wfParseUrl( $url ) {
 794         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 795
 796         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 797         // bad that the easiest way to handle them is to just prepend 'http:' and
 798         // strip the protocol out later.
 799         $wasRelative = substr( $url, 0, 2 ) == '//';
 800         if ( $wasRelative ) {
 801                 $url = "http:$url";
 802         }
 803         AtEase::suppressWarnings();
 804         $bits = parse_url( $url );
 805         AtEase::restoreWarnings();
 806         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 807         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 808         if ( !$bits || !isset( $bits['scheme'] ) ) {
 809                 return false;
 810         }
 811
 812         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 813         $bits['scheme'] = strtolower( $bits['scheme'] );
 814
 815         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 816         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 817                 $bits['delimiter'] = '://';
 818         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 819                 $bits['delimiter'] = ':';
 820                 // parse_url detects for news: and mailto: the host part of an url as path
 821                 // We have to correct this wrong detection
 822                 if ( isset( $bits['path'] ) ) {
 823                         $bits['host'] = $bits['path'];
 824                         $bits['path'] = '';
 825                 }
 826         } else {
 827                 return false;
 828         }
 829
 830         /* Provide an empty host for eg. file:/// urls (see T30627) */
 831         if ( !isset( $bits['host'] ) ) {
 832                 $bits['host'] = '';
 833
 834                 // See T47069
 835                 if ( isset( $bits['path'] ) ) {
 836                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 837                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 838                                 $bits['path'] = '/' . $bits['path'];
 839                         }
 840                 } else {
 841                         $bits['path'] = '';
 842                 }
 843         }
 844
 845         // If the URL was protocol-relative, fix scheme and delimiter
 846         if ( $wasRelative ) {
 847                 $bits['scheme'] = '';
 848                 $bits['delimiter'] = '//';
 849         }
 850         return $bits;
 851 }
 852
 853 /**
 854  * Take a URL, make sure it's expanded to fully qualified, and replace any
 855  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 856  * for more compact display and legibility for local audiences.
 857  *
 858  * @todo handle punycode domains too
 859  *
 860  * @param string $url
 861  * @return string
 862  */
 863 function wfExpandIRI( $url ) {
 864         return preg_replace_callback(
 865                 '/((?:%[89A-F][0-9A-F])+)/i',
 866                 function ( array $matches ) {
 867                         return urldecode( $matches[1] );
 868                 },
 869                 wfExpandUrl( $url )
 870         );
 871 }
 872
 873 /**
 874  * Check whether a given URL has a domain that occurs in a given set of domains
 875  * @param string $url
 876  * @param array $domains Array of domains (strings)
 877  * @return bool True if the host part of $url ends in one of the strings in $domains
 878  */
 879 function wfMatchesDomainList( $url, $domains ) {
 880         $bits = wfParseUrl( $url );
 881         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 882                 $host = '.' . $bits['host'];
 883                 foreach ( (array)$domains as $domain ) {
 884                         $domain = '.' . $domain;
 885                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 886                                 return true;
 887                         }
 888                 }
 889         }
 890         return false;
 891 }
 892
 893 /**
 894  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 895  * In normal operation this is a NOP.
 896  *
 897  * Controlling globals:
 898  * $wgDebugLogFile - points to the log file
 899  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 900  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 901  *
 902  * @since 1.25 support for additional context data
 903  *
 904  * @param string $text
 905  * @param string|bool $dest Destination of the message:
 906  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 907  *     - 'private': excluded from HTML output
 908  *   For backward compatibility, it can also take a boolean:
 909  *     - true: same as 'all'
 910  *     - false: same as 'private'
 911  * @param array $context Additional logging context data
 912  */
 913 function wfDebug( $text, $dest = 'all', array $context = [] ) {
 914         global $wgDebugRawPage, $wgDebugLogPrefix;
 915         global $wgDebugTimestamps;
 916
 917         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 918                 return;
 919         }
 920
 921         $text = trim( $text );
 922
 923         if ( $wgDebugTimestamps ) {
 924                 $context['seconds_elapsed'] = sprintf(
 925                         '%6.4f',
 926                         microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT']
 927                 );
 928                 $context['memory_used'] = sprintf(
 929                         '%5.1fM',
 930                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
 931                 );
 932         }
 933
 934         if ( $wgDebugLogPrefix !== '' ) {
 935                 $context['prefix'] = $wgDebugLogPrefix;
 936         }
 937         $context['private'] = ( $dest === false || $dest === 'private' );
 938
 939         $logger = LoggerFactory::getInstance( 'wfDebug' );
 940         $logger->debug( $text, $context );
 941 }
 942
 943 /**
 944  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 945  * @return bool
 946  */
 947 function wfIsDebugRawPage() {
 948         static $cache;
 949         if ( $cache !== null ) {
 950                 return $cache;
 951         }
 952         // Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 953         // phpcs:ignore MediaWiki.Usage.SuperGlobalsUsage.SuperGlobals
 954         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 955                 || (
 956                         isset( $_SERVER['SCRIPT_NAME'] )
 957                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 958                 )
 959         ) {
 960                 $cache = true;
 961         } else {
 962                 $cache = false;
 963         }
 964         return $cache;
 965 }
 966
 967 /**
 968  * Send a line giving PHP memory usage.
 969  *
 970  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
 971  */
 972 function wfDebugMem( $exact = false ) {
 973         $mem = memory_get_usage();
 974         if ( !$exact ) {
 975                 $mem = floor( $mem / 1024 ) . ' KiB';
 976         } else {
 977                 $mem .= ' B';
 978         }
 979         wfDebug( "Memory usage: $mem\n" );
 980 }
 981
 982 /**
 983  * Send a line to a supplementary debug log file, if configured, or main debug
 984  * log if not.
 985  *
 986  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
 987  * a string filename or an associative array mapping 'destination' to the
 988  * desired filename. The associative array may also contain a 'sample' key
 989  * with an integer value, specifying a sampling factor. Sampled log events
 990  * will be emitted with a 1 in N random chance.
 991  *
 992  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
 993  * @since 1.25 support for additional context data
 994  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
 995  *
 996  * @param string $logGroup
 997  * @param string $text
 998  * @param string|bool $dest Destination of the message:
 999  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1000  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1001  *       discarded otherwise
1002  *   For backward compatibility, it can also take a boolean:
1003  *     - true: same as 'all'
1004  *     - false: same as 'private'
1005  * @param array $context Additional logging context data
1006  */
1007 function wfDebugLog(
1008         $logGroup, $text, $dest = 'all', array $context = []
1009 ) {
1010         $text = trim( $text );
1011
1012         $logger = LoggerFactory::getInstance( $logGroup );
1013         $context['private'] = ( $dest === false || $dest === 'private' );
1014         $logger->info( $text, $context );
1015 }
1016
1017 /**
1018  * Log for database errors
1019  *
1020  * @since 1.25 support for additional context data
1021  *
1022  * @param string $text Database error message.
1023  * @param array $context Additional logging context data
1024  */
1025 function wfLogDBError( $text, array $context = [] ) {
1026         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1027         $logger->error( trim( $text ), $context );
1028 }
1029
1030 /**
1031  * Throws a warning that $function is deprecated
1032  *
1033  * @param string $function Function that is deprecated.
1034  * @param string|bool $version Version of MediaWiki that the function
1035  *    was deprecated in (Added in 1.19).
1036  * @param string|bool $component Component to which the function belongs.
1037  *    If false, it is assumed the function is in MediaWiki core (Added in 1.19).
1038  * @param int $callerOffset How far up the call stack is the original
1039  *    caller. 2 = function that called the function that called
1040  *    wfDeprecated (Added in 1.20).
1041  */
1042 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1043         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1044 }
1045
1046 /**
1047  * Send a warning either to the debug log or in a PHP error depending on
1048  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1049  *
1050  * @param string $msg Message to send
1051  * @param int $callerOffset Number of items to go back in the backtrace to
1052  *        find the correct caller (1 = function calling wfWarn, ...)
1053  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1054  *        only used when $wgDevelopmentWarnings is true
1055  */
1056 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1057         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1058 }
1059
1060 /**
1061  * Send a warning as a PHP error and the debug log. This is intended for logging
1062  * warnings in production. For logging development warnings, use WfWarn instead.
1063  *
1064  * @param string $msg Message to send
1065  * @param int $callerOffset Number of items to go back in the backtrace to
1066  *        find the correct caller (1 = function calling wfLogWarning, ...)
1067  * @param int $level PHP error level; defaults to E_USER_WARNING
1068  */
1069 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1070         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1071 }
1072
1073 /**
1074  * @todo document
1075  * @todo Move logic to MediaWiki.php
1076  */
1077 function wfLogProfilingData() {
1078         global $wgDebugLogGroups, $wgDebugRawPage;
1079
1080         $context = RequestContext::getMain();
1081         $request = $context->getRequest();
1082
1083         $profiler = Profiler::instance();
1084         $profiler->setContext( $context );
1085         $profiler->logData();
1086
1087         // Send out any buffered statsd metrics as needed
1088         MediaWiki::emitBufferedStatsdData(
1089                 MediaWikiServices::getInstance()->getStatsdDataFactory(),
1090                 $context->getConfig()
1091         );
1092
1093         // Profiling must actually be enabled...
1094         if ( $profiler instanceof ProfilerStub ) {
1095                 return;
1096         }
1097
1098         if ( isset( $wgDebugLogGroups['profileoutput'] )
1099                 && $wgDebugLogGroups['profileoutput'] === false
1100         ) {
1101                 // Explicitly disabled
1102                 return;
1103         }
1104         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1105                 return;
1106         }
1107
1108         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1109         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1110                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1111         }
1112         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1113                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1114         }
1115         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1116                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1117         }
1118         if ( isset( $ctx['forwarded_for'] ) ||
1119                 isset( $ctx['client_ip'] ) ||
1120                 isset( $ctx['from'] ) ) {
1121                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1122         }
1123
1124         // Don't load $wgUser at this late stage just for statistics purposes
1125         // @todo FIXME: We can detect some anons even if it is not loaded.
1126         // See User::getId()
1127         $user = $context->getUser();
1128         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1129
1130         // Command line script uses a FauxRequest object which does not have
1131         // any knowledge about an URL and throw an exception instead.
1132         try {
1133                 $ctx['url'] = urldecode( $request->getRequestURL() );
1134         } catch ( Exception $ignored ) {
1135                 // no-op
1136         }
1137
1138         $ctx['output'] = $profiler->getOutput();
1139
1140         $log = LoggerFactory::getInstance( 'profileoutput' );
1141         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1142 }
1143
1144 /**
1145  * Increment a statistics counter
1146  *
1147  * @param string $key
1148  * @param int $count
1149  * @return void
1150  */
1151 function wfIncrStats( $key, $count = 1 ) {
1152         $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1153         $stats->updateCount( $key, $count );
1154 }
1155
1156 /**
1157  * Check whether the wiki is in read-only mode.
1158  *
1159  * @return bool
1160  */
1161 function wfReadOnly() {
1162         return MediaWikiServices::getInstance()->getReadOnlyMode()
1163                 ->isReadOnly();
1164 }
1165
1166 /**
1167  * Check if the site is in read-only mode and return the message if so
1168  *
1169  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1170  * for replica DB lag. This may result in DB connection being made.
1171  *
1172  * @return string|bool String when in read-only mode; false otherwise
1173  */
1174 function wfReadOnlyReason() {
1175         return MediaWikiServices::getInstance()->getReadOnlyMode()
1176                 ->getReason();
1177 }
1178
1179 /**
1180  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1181  *
1182  * @return string|bool String when in read-only mode; false otherwise
1183  * @since 1.27
1184  */
1185 function wfConfiguredReadOnlyReason() {
1186         return MediaWikiServices::getInstance()->getConfiguredReadOnlyMode()
1187                 ->getReason();
1188 }
1189
1190 /**
1191  * Return a Language object from $langcode
1192  *
1193  * @param Language|string|bool $langcode Either:
1194  *                  - a Language object
1195  *                  - code of the language to get the message for, if it is
1196  *                    a valid code create a language for that language, if
1197  *                    it is a string but not a valid code then make a basic
1198  *                    language object
1199  *                  - a boolean: if it's false then use the global object for
1200  *                    the current user's language (as a fallback for the old parameter
1201  *                    functionality), or if it is true then use global object
1202  *                    for the wiki's content language.
1203  * @return Language
1204  */
1205 function wfGetLangObj( $langcode = false ) {
1206         # Identify which language to get or create a language object for.
1207         # Using is_object here due to Stub objects.
1208         if ( is_object( $langcode ) ) {
1209                 # Great, we already have the object (hopefully)!
1210                 return $langcode;
1211         }
1212
1213         global $wgLanguageCode;
1214         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1215                 # $langcode is the language code of the wikis content language object.
1216                 # or it is a boolean and value is true
1217                 return MediaWikiServices::getInstance()->getContentLanguage();
1218         }
1219
1220         global $wgLang;
1221         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1222                 # $langcode is the language code of user language object.
1223                 # or it was a boolean and value is false
1224                 return $wgLang;
1225         }
1226
1227         $validCodes = array_keys( Language::fetchLanguageNames() );
1228         if ( in_array( $langcode, $validCodes ) ) {
1229                 # $langcode corresponds to a valid language.
1230                 return Language::factory( $langcode );
1231         }
1232
1233         # $langcode is a string, but not a valid language code; use content language.
1234         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1235         return MediaWikiServices::getInstance()->getContentLanguage();
1236 }
1237
1238 /**
1239  * This is the function for getting translated interface messages.
1240  *
1241  * @see Message class for documentation how to use them.
1242  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1243  *
1244  * This function replaces all old wfMsg* functions.
1245  *
1246  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1247  * @param string|string[] ...$params Normal message parameters
1248  * @return Message
1249  *
1250  * @since 1.17
1251  *
1252  * @see Message::__construct
1253  */
1254 function wfMessage( $key, ...$params ) {
1255         $message = new Message( $key );
1256
1257         // We call Message::params() to reduce code duplication
1258         if ( $params ) {
1259                 $message->params( ...$params );
1260         }
1261
1262         return $message;
1263 }
1264
1265 /**
1266  * This function accepts multiple message keys and returns a message instance
1267  * for the first message which is non-empty. If all messages are empty then an
1268  * instance of the first message key is returned.
1269  *
1270  * @param string ...$keys Message keys
1271  * @return Message
1272  *
1273  * @since 1.18
1274  *
1275  * @see Message::newFallbackSequence
1276  */
1277 function wfMessageFallback( ...$keys ) {
1278         return Message::newFallbackSequence( ...$keys );
1279 }
1280
1281 /**
1282  * Replace message parameter keys on the given formatted output.
1283  *
1284  * @param string $message
1285  * @param array $args
1286  * @return string
1287  * @private
1288  */
1289 function wfMsgReplaceArgs( $message, $args ) {
1290         # Fix windows line-endings
1291         # Some messages are split with explode("\n", $msg)
1292         $message = str_replace( "\r", '', $message );
1293
1294         // Replace arguments
1295         if ( is_array( $args ) && $args ) {
1296                 if ( is_array( $args[0] ) ) {
1297                         $args = array_values( $args[0] );
1298                 }
1299                 $replacementKeys = [];
1300                 foreach ( $args as $n => $param ) {
1301                         $replacementKeys['$' . ( $n + 1 )] = $param;
1302                 }
1303                 $message = strtr( $message, $replacementKeys );
1304         }
1305
1306         return $message;
1307 }
1308
1309 /**
1310  * Fetch server name for use in error reporting etc.
1311  * Use real server name if available, so we know which machine
1312  * in a server farm generated the current page.
1313  *
1314  * @return string
1315  */
1316 function wfHostname() {
1317         static $host;
1318         if ( is_null( $host ) ) {
1319                 # Hostname overriding
1320                 global $wgOverrideHostname;
1321                 if ( $wgOverrideHostname !== false ) {
1322                         # Set static and skip any detection
1323                         $host = $wgOverrideHostname;
1324                         return $host;
1325                 }
1326
1327                 if ( function_exists( 'posix_uname' ) ) {
1328                         // This function not present on Windows
1329                         $uname = posix_uname();
1330                 } else {
1331                         $uname = false;
1332                 }
1333                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1334                         $host = $uname['nodename'];
1335                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1336                         # Windows computer name
1337                         $host = getenv( 'COMPUTERNAME' );
1338                 } else {
1339                         # This may be a virtual server.
1340                         $host = $_SERVER['SERVER_NAME'];
1341                 }
1342         }
1343         return $host;
1344 }
1345
1346 /**
1347  * Returns a script tag that stores the amount of time it took MediaWiki to
1348  * handle the request in milliseconds as 'wgBackendResponseTime'.
1349  *
1350  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1351  * hostname of the server handling the request.
1352  *
1353  * @param string|null $nonce Value from OutputPage::getCSPNonce
1354  * @return string|WrappedString HTML
1355  */
1356 function wfReportTime( $nonce = null ) {
1357         global $wgShowHostnames;
1358
1359         $elapsed = ( microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT'] );
1360         // seconds to milliseconds
1361         $responseTime = round( $elapsed * 1000 );
1362         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1363         if ( $wgShowHostnames ) {
1364                 $reportVars['wgHostname'] = wfHostname();
1365         }
1366         return Skin::makeVariablesScript( $reportVars, $nonce );
1367 }
1368
1369 /**
1370  * Safety wrapper for debug_backtrace().
1371  *
1372  * Will return an empty array if debug_backtrace is disabled, otherwise
1373  * the output from debug_backtrace() (trimmed).
1374  *
1375  * @param int $limit This parameter can be used to limit the number of stack frames returned
1376  *
1377  * @return array Array of backtrace information
1378  */
1379 function wfDebugBacktrace( $limit = 0 ) {
1380         static $disabled = null;
1381
1382         if ( is_null( $disabled ) ) {
1383                 $disabled = !function_exists( 'debug_backtrace' );
1384                 if ( $disabled ) {
1385                         wfDebug( "debug_backtrace() is disabled\n" );
1386                 }
1387         }
1388         if ( $disabled ) {
1389                 return [];
1390         }
1391
1392         if ( $limit ) {
1393                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1394         } else {
1395                 return array_slice( debug_backtrace(), 1 );
1396         }
1397 }
1398
1399 /**
1400  * Get a debug backtrace as a string
1401  *
1402  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1403  *   Defaults to $wgCommandLineMode if unset.
1404  * @return string
1405  * @since 1.25 Supports $raw parameter.
1406  */
1407 function wfBacktrace( $raw = null ) {
1408         global $wgCommandLineMode;
1409
1410         if ( $raw === null ) {
1411                 $raw = $wgCommandLineMode;
1412         }
1413
1414         if ( $raw ) {
1415                 $frameFormat = "%s line %s calls %s()\n";
1416                 $traceFormat = "%s";
1417         } else {
1418                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1419                 $traceFormat = "<ul>\n%s</ul>\n";
1420         }
1421
1422         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1423                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1424                 $line = $frame['line'] ?? '-';
1425                 $call = $frame['function'];
1426                 if ( !empty( $frame['class'] ) ) {
1427                         $call = $frame['class'] . $frame['type'] . $call;
1428                 }
1429                 return sprintf( $frameFormat, $file, $line, $call );
1430         }, wfDebugBacktrace() );
1431
1432         return sprintf( $traceFormat, implode( '', $frames ) );
1433 }
1434
1435 /**
1436  * Get the name of the function which called this function
1437  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1438  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1439  * wfGetCaller( 3 ) is the parent of that.
1440  *
1441  * @param int $level
1442  * @return string
1443  */
1444 function wfGetCaller( $level = 2 ) {
1445         $backtrace = wfDebugBacktrace( $level + 1 );
1446         if ( isset( $backtrace[$level] ) ) {
1447                 return wfFormatStackFrame( $backtrace[$level] );
1448         } else {
1449                 return 'unknown';
1450         }
1451 }
1452
1453 /**
1454  * Return a string consisting of callers in the stack. Useful sometimes
1455  * for profiling specific points.
1456  *
1457  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1458  * @return string
1459  */
1460 function wfGetAllCallers( $limit = 3 ) {
1461         $trace = array_reverse( wfDebugBacktrace() );
1462         if ( !$limit || $limit > count( $trace ) - 1 ) {
1463                 $limit = count( $trace ) - 1;
1464         }
1465         $trace = array_slice( $trace, -$limit - 1, $limit );
1466         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1467 }
1468
1469 /**
1470  * Return a string representation of frame
1471  *
1472  * @param array $frame
1473  * @return string
1474  */
1475 function wfFormatStackFrame( $frame ) {
1476         if ( !isset( $frame['function'] ) ) {
1477                 return 'NO_FUNCTION_GIVEN';
1478         }
1479         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1480                 $frame['class'] . $frame['type'] . $frame['function'] :
1481                 $frame['function'];
1482 }
1483
1484 /* Some generic result counters, pulled out of SearchEngine */
1485
1486 /**
1487  * @todo document
1488  *
1489  * @param int $offset
1490  * @param int $limit
1491  * @return string
1492  */
1493 function wfShowingResults( $offset, $limit ) {
1494         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1495 }
1496
1497 /**
1498  * Whether the client accept gzip encoding
1499  *
1500  * Uses the Accept-Encoding header to check if the client supports gzip encoding.
1501  * Use this when considering to send a gzip-encoded response to the client.
1502  *
1503  * @param bool $force Forces another check even if we already have a cached result.
1504  * @return bool
1505  */
1506 function wfClientAcceptsGzip( $force = false ) {
1507         static $result = null;
1508         if ( $result === null || $force ) {
1509                 $result = false;
1510                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1511                         # @todo FIXME: We may want to blacklist some broken browsers
1512                         $m = [];
1513                         if ( preg_match(
1514                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1515                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1516                                         $m
1517                                 )
1518                         ) {
1519                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1520                                         $result = false;
1521                                         return $result;
1522                                 }
1523                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1524                                 $result = true;
1525                         }
1526                 }
1527         }
1528         return $result;
1529 }
1530
1531 /**
1532  * Escapes the given text so that it may be output using addWikiText()
1533  * without any linking, formatting, etc. making its way through. This
1534  * is achieved by substituting certain characters with HTML entities.
1535  * As required by the callers, "<nowiki>" is not used.
1536  *
1537  * @param string $text Text to be escaped
1538  * @param-taint $text escapes_html
1539  * @return string
1540  */
1541 function wfEscapeWikiText( $text ) {
1542         global $wgEnableMagicLinks;
1543         static $repl = null, $repl2 = null;
1544         if ( $repl === null || defined( 'MW_PARSER_TEST' ) || defined( 'MW_PHPUNIT_TEST' ) ) {
1545                 // Tests depend upon being able to change $wgEnableMagicLinks, so don't cache
1546                 // in those situations
1547                 $repl = [
1548                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1549                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1550                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1551                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1552                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1553                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1554                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1555                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1556                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1557                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1558                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1559                         '__' => '_&#95;', '://' => '&#58;//',
1560                 ];
1561
1562                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1563                 // We have to catch everything "\s" matches in PCRE
1564                 foreach ( $magicLinks as $magic ) {
1565                         $repl["$magic "] = "$magic&#32;";
1566                         $repl["$magic\t"] = "$magic&#9;";
1567                         $repl["$magic\r"] = "$magic&#13;";
1568                         $repl["$magic\n"] = "$magic&#10;";
1569                         $repl["$magic\f"] = "$magic&#12;";
1570                 }
1571
1572                 // And handle protocols that don't use "://"
1573                 global $wgUrlProtocols;
1574                 $repl2 = [];
1575                 foreach ( $wgUrlProtocols as $prot ) {
1576                         if ( substr( $prot, -1 ) === ':' ) {
1577                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1578                         }
1579                 }
1580                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1581         }
1582         $text = substr( strtr( "\n$text", $repl ), 1 );
1583         $text = preg_replace( $repl2, '$1&#58;', $text );
1584         return $text;
1585 }
1586
1587 /**
1588  * Sets dest to source and returns the original value of dest
1589  * If source is NULL, it just returns the value, it doesn't set the variable
1590  * If force is true, it will set the value even if source is NULL
1591  *
1592  * @param mixed &$dest
1593  * @param mixed $source
1594  * @param bool $force
1595  * @return mixed
1596  */
1597 function wfSetVar( &$dest, $source, $force = false ) {
1598         $temp = $dest;
1599         if ( !is_null( $source ) || $force ) {
1600                 $dest = $source;
1601         }
1602         return $temp;
1603 }
1604
1605 /**
1606  * As for wfSetVar except setting a bit
1607  *
1608  * @param int &$dest
1609  * @param int $bit
1610  * @param bool $state
1611  *
1612  * @return bool
1613  */
1614 function wfSetBit( &$dest, $bit, $state = true ) {
1615         $temp = (bool)( $dest & $bit );
1616         if ( !is_null( $state ) ) {
1617                 if ( $state ) {
1618                         $dest |= $bit;
1619                 } else {
1620                         $dest &= ~$bit;
1621                 }
1622         }
1623         return $temp;
1624 }
1625
1626 /**
1627  * A wrapper around the PHP function var_export().
1628  * Either print it or add it to the regular output ($wgOut).
1629  *
1630  * @param mixed $var A PHP variable to dump.
1631  */
1632 function wfVarDump( $var ) {
1633         global $wgOut;
1634         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1635         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1636                 print $s;
1637         } else {
1638                 $wgOut->addHTML( $s );
1639         }
1640 }
1641
1642 /**
1643  * Provide a simple HTTP error.
1644  *
1645  * @param int|string $code
1646  * @param string $label
1647  * @param string $desc
1648  */
1649 function wfHttpError( $code, $label, $desc ) {
1650         global $wgOut;
1651         HttpStatus::header( $code );
1652         if ( $wgOut ) {
1653                 $wgOut->disable();
1654                 $wgOut->sendCacheControl();
1655         }
1656
1657         MediaWiki\HeaderCallback::warnIfHeadersSent();
1658         header( 'Content-type: text/html; charset=utf-8' );
1659         print '<!DOCTYPE html>' .
1660                 '<html><head><title>' .
1661                 htmlspecialchars( $label ) .
1662                 '</title></head><body><h1>' .
1663                 htmlspecialchars( $label ) .
1664                 '</h1><p>' .
1665                 nl2br( htmlspecialchars( $desc ) ) .
1666                 "</p></body></html>\n";
1667 }
1668
1669 /**
1670  * Clear away any user-level output buffers, discarding contents.
1671  *
1672  * Suitable for 'starting afresh', for instance when streaming
1673  * relatively large amounts of data without buffering, or wanting to
1674  * output image files without ob_gzhandler's compression.
1675  *
1676  * The optional $resetGzipEncoding parameter controls suppression of
1677  * the Content-Encoding header sent by ob_gzhandler; by default it
1678  * is left. See comments for wfClearOutputBuffers() for why it would
1679  * be used.
1680  *
1681  * Note that some PHP configuration options may add output buffer
1682  * layers which cannot be removed; these are left in place.
1683  *
1684  * @param bool $resetGzipEncoding
1685  */
1686 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1687         if ( $resetGzipEncoding ) {
1688                 // Suppress Content-Encoding and Content-Length
1689                 // headers from OutputHandler::handle.
1690                 global $wgDisableOutputCompression;
1691                 $wgDisableOutputCompression = true;
1692         }
1693         while ( $status = ob_get_status() ) {
1694                 if ( isset( $status['flags'] ) ) {
1695                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1696                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1697                 } elseif ( isset( $status['del'] ) ) {
1698                         $deleteable = $status['del'];
1699                 } else {
1700                         // Guess that any PHP-internal setting can't be removed.
1701                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1702                 }
1703                 if ( !$deleteable ) {
1704                         // Give up, and hope the result doesn't break
1705                         // output behavior.
1706                         break;
1707                 }
1708                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1709                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1710                         break;
1711                 }
1712                 if ( !ob_end_clean() ) {
1713                         // Could not remove output buffer handler; abort now
1714                         // to avoid getting in some kind of infinite loop.
1715                         break;
1716                 }
1717                 if ( $resetGzipEncoding && $status['name'] == 'ob_gzhandler' ) {
1718                         // Reset the 'Content-Encoding' field set by this handler
1719                         // so we can start fresh.
1720                         header_remove( 'Content-Encoding' );
1721                         break;
1722                 }
1723         }
1724 }
1725
1726 /**
1727  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1728  *
1729  * Clear away output buffers, but keep the Content-Encoding header
1730  * produced by ob_gzhandler, if any.
1731  *
1732  * This should be used for HTTP 304 responses, where you need to
1733  * preserve the Content-Encoding header of the real result, but
1734  * also need to suppress the output of ob_gzhandler to keep to spec
1735  * and avoid breaking Firefox in rare cases where the headers and
1736  * body are broken over two packets.
1737  */
1738 function wfClearOutputBuffers() {
1739         wfResetOutputBuffers( false );
1740 }
1741
1742 /**
1743  * Converts an Accept-* header into an array mapping string values to quality
1744  * factors
1745  *
1746  * @param string $accept
1747  * @param string $def Default
1748  * @return float[] Associative array of string => float pairs
1749  */
1750 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1751         # No arg means accept anything (per HTTP spec)
1752         if ( !$accept ) {
1753                 return [ $def => 1.0 ];
1754         }
1755
1756         $prefs = [];
1757
1758         $parts = explode( ',', $accept );
1759
1760         foreach ( $parts as $part ) {
1761                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1762                 $values = explode( ';', trim( $part ) );
1763                 $match = [];
1764                 if ( count( $values ) == 1 ) {
1765                         $prefs[$values[0]] = 1.0;
1766                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1767                         $prefs[$values[0]] = floatval( $match[1] );
1768                 }
1769         }
1770
1771         return $prefs;
1772 }
1773
1774 /**
1775  * Checks if a given MIME type matches any of the keys in the given
1776  * array. Basic wildcards are accepted in the array keys.
1777  *
1778  * Returns the matching MIME type (or wildcard) if a match, otherwise
1779  * NULL if no match.
1780  *
1781  * @param string $type
1782  * @param array $avail
1783  * @return string
1784  * @private
1785  */
1786 function mimeTypeMatch( $type, $avail ) {
1787         if ( array_key_exists( $type, $avail ) ) {
1788                 return $type;
1789         } else {
1790                 $mainType = explode( '/', $type )[0];
1791                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1792                         return "$mainType/*";
1793                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1794                         return '*/*';
1795                 } else {
1796                         return null;
1797                 }
1798         }
1799 }
1800
1801 /**
1802  * Returns the 'best' match between a client's requested internet media types
1803  * and the server's list of available types. Each list should be an associative
1804  * array of type to preference (preference is a float between 0.0 and 1.0).
1805  * Wildcards in the types are acceptable.
1806  *
1807  * @param array $cprefs Client's acceptable type list
1808  * @param array $sprefs Server's offered types
1809  * @return string
1810  *
1811  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1812  * XXX: generalize to negotiate other stuff
1813  */
1814 function wfNegotiateType( $cprefs, $sprefs ) {
1815         $combine = [];
1816
1817         foreach ( array_keys( $sprefs ) as $type ) {
1818                 $subType = explode( '/', $type )[1];
1819                 if ( $subType != '*' ) {
1820                         $ckey = mimeTypeMatch( $type, $cprefs );
1821                         if ( $ckey ) {
1822                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1823                         }
1824                 }
1825         }
1826
1827         foreach ( array_keys( $cprefs ) as $type ) {
1828                 $subType = explode( '/', $type )[1];
1829                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1830                         $skey = mimeTypeMatch( $type, $sprefs );
1831                         if ( $skey ) {
1832                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1833                         }
1834                 }
1835         }
1836
1837         $bestq = 0;
1838         $besttype = null;
1839
1840         foreach ( array_keys( $combine ) as $type ) {
1841                 if ( $combine[$type] > $bestq ) {
1842                         $besttype = $type;
1843                         $bestq = $combine[$type];
1844                 }
1845         }
1846
1847         return $besttype;
1848 }
1849
1850 /**
1851  * Get a timestamp string in one of various formats
1852  *
1853  * @param mixed $outputtype A timestamp in one of the supported formats, the
1854  *   function will autodetect which format is supplied and act accordingly.
1855  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
1856  * @return string|bool String / false The same date in the format specified in $outputtype or false
1857  */
1858 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
1859         $ret = MWTimestamp::convert( $outputtype, $ts );
1860         if ( $ret === false ) {
1861                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
1862         }
1863         return $ret;
1864 }
1865
1866 /**
1867  * Return a formatted timestamp, or null if input is null.
1868  * For dealing with nullable timestamp columns in the database.
1869  *
1870  * @param int $outputtype
1871  * @param string|null $ts
1872  * @return string
1873  */
1874 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
1875         if ( is_null( $ts ) ) {
1876                 return null;
1877         } else {
1878                 return wfTimestamp( $outputtype, $ts );
1879         }
1880 }
1881
1882 /**
1883  * Convenience function; returns MediaWiki timestamp for the present time.
1884  *
1885  * @return string
1886  */
1887 function wfTimestampNow() {
1888         # return NOW
1889         return MWTimestamp::now( TS_MW );
1890 }
1891
1892 /**
1893  * Check if the operating system is Windows
1894  *
1895  * @return bool True if it's Windows, false otherwise.
1896  */
1897 function wfIsWindows() {
1898         static $isWindows = null;
1899         if ( $isWindows === null ) {
1900                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
1901         }
1902         return $isWindows;
1903 }
1904
1905 /**
1906  * Check if we are running under HHVM
1907  *
1908  * @return bool
1909  */
1910 function wfIsHHVM() {
1911         return defined( 'HHVM_VERSION' );
1912 }
1913
1914 /**
1915  * Check if we are running from the commandline
1916  *
1917  * @since 1.31
1918  * @return bool
1919  */
1920 function wfIsCLI() {
1921         return PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg';
1922 }
1923
1924 /**
1925  * Tries to get the system directory for temporary files. First
1926  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
1927  * environment variables are then checked in sequence, then
1928  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
1929  *
1930  * NOTE: When possible, use instead the tmpfile() function to create
1931  * temporary files to avoid race conditions on file creation, etc.
1932  *
1933  * @return string
1934  */
1935 function wfTempDir() {
1936         global $wgTmpDirectory;
1937
1938         if ( $wgTmpDirectory !== false ) {
1939                 return $wgTmpDirectory;
1940         }
1941
1942         return TempFSFile::getUsableTempDirectory();
1943 }
1944
1945 /**
1946  * Make directory, and make all parent directories if they don't exist
1947  *
1948  * @param string $dir Full path to directory to create
1949  * @param int|null $mode Chmod value to use, default is $wgDirectoryMode
1950  * @param string|null $caller Optional caller param for debugging.
1951  * @throws MWException
1952  * @return bool
1953  */
1954 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
1955         global $wgDirectoryMode;
1956
1957         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
1958                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
1959         }
1960
1961         if ( !is_null( $caller ) ) {
1962                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
1963         }
1964
1965         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
1966                 return true;
1967         }
1968
1969         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
1970
1971         if ( is_null( $mode ) ) {
1972                 $mode = $wgDirectoryMode;
1973         }
1974
1975         // Turn off the normal warning, we're doing our own below
1976         AtEase::suppressWarnings();
1977         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
1978         AtEase::restoreWarnings();
1979
1980         if ( !$ok ) {
1981                 // directory may have been created on another request since we last checked
1982                 if ( is_dir( $dir ) ) {
1983                         return true;
1984                 }
1985
1986                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
1987                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
1988         }
1989         return $ok;
1990 }
1991
1992 /**
1993  * Remove a directory and all its content.
1994  * Does not hide error.
1995  * @param string $dir
1996  */
1997 function wfRecursiveRemoveDir( $dir ) {
1998         wfDebug( __FUNCTION__ . "( $dir )\n" );
1999         // taken from https://www.php.net/manual/en/function.rmdir.php#98622
2000         if ( is_dir( $dir ) ) {
2001                 $objects = scandir( $dir );
2002                 foreach ( $objects as $object ) {
2003                         if ( $object != "." && $object != ".." ) {
2004                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2005                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2006                                 } else {
2007                                         unlink( $dir . '/' . $object );
2008                                 }
2009                         }
2010                 }
2011                 reset( $objects );
2012                 rmdir( $dir );
2013         }
2014 }
2015
2016 /**
2017  * @param int $nr The number to format
2018  * @param int $acc The number of digits after the decimal point, default 2
2019  * @param bool $round Whether or not to round the value, default true
2020  * @return string
2021  */
2022 function wfPercent( $nr, $acc = 2, $round = true ) {
2023         $ret = sprintf( "%.${acc}f", $nr );
2024         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2025 }
2026
2027 /**
2028  * Safety wrapper around ini_get() for boolean settings.
2029  * The values returned from ini_get() are pre-normalized for settings
2030  * set via php.ini or php_flag/php_admin_flag... but *not*
2031  * for those set via php_value/php_admin_value.
2032  *
2033  * It's fairly common for people to use php_value instead of php_flag,
2034  * which can leave you with an 'off' setting giving a false positive
2035  * for code that just takes the ini_get() return value as a boolean.
2036  *
2037  * To make things extra interesting, setting via php_value accepts
2038  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2039  * Unrecognized values go false... again opposite PHP's own coercion
2040  * from string to bool.
2041  *
2042  * Luckily, 'properly' set settings will always come back as '0' or '1',
2043  * so we only have to worry about them and the 'improper' settings.
2044  *
2045  * I frickin' hate PHP... :P
2046  *
2047  * @param string $setting
2048  * @return bool
2049  */
2050 function wfIniGetBool( $setting ) {
2051         return wfStringToBool( ini_get( $setting ) );
2052 }
2053
2054 /**
2055  * Convert string value to boolean, when the following are interpreted as true:
2056  * - on
2057  * - true
2058  * - yes
2059  * - Any number, except 0
2060  * All other strings are interpreted as false.
2061  *
2062  * @param string $val
2063  * @return bool
2064  * @since 1.31
2065  */
2066 function wfStringToBool( $val ) {
2067         $val = strtolower( $val );
2068         // 'on' and 'true' can't have whitespace around them, but '1' can.
2069         return $val == 'on'
2070                 || $val == 'true'
2071                 || $val == 'yes'
2072                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2073 }
2074
2075 /**
2076  * Version of escapeshellarg() that works better on Windows.
2077  *
2078  * Originally, this fixed the incorrect use of single quotes on Windows
2079  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2080  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2081  *
2082  * @param string|string[] ...$args strings to escape and glue together,
2083  *  or a single array of strings parameter
2084  * @return string
2085  * @deprecated since 1.30 use MediaWiki\Shell\Shell::escape()
2086  */
2087 function wfEscapeShellArg( ...$args ) {
2088         return Shell::escape( ...$args );
2089 }
2090
2091 /**
2092  * Execute a shell command, with time and memory limits mirrored from the PHP
2093  * configuration if supported.
2094  *
2095  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2096  *   or an array of unescaped arguments, in which case each value will be escaped
2097  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2098  * @param null|mixed &$retval Optional, will receive the program's exit code.
2099  *   (non-zero is usually failure). If there is an error from
2100  *   read, select, or proc_open(), this will be set to -1.
2101  * @param array $environ Optional environment variables which should be
2102  *   added to the executed command environment.
2103  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2104  *   this overwrites the global wgMaxShell* limits.
2105  * @param array $options Array of options:
2106  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2107  *     including errors from limit.sh
2108  *   - profileMethod: By default this function will profile based on the calling
2109  *     method. Set this to a string for an alternative method to profile from
2110  *
2111  * @return string Collected stdout as a string
2112  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2113  */
2114 function wfShellExec( $cmd, &$retval = null, $environ = [],
2115         $limits = [], $options = []
2116 ) {
2117         if ( Shell::isDisabled() ) {
2118                 $retval = 1;
2119                 // Backwards compatibility be upon us...
2120                 return 'Unable to run external programs, proc_open() is disabled.';
2121         }
2122
2123         if ( is_array( $cmd ) ) {
2124                 $cmd = Shell::escape( $cmd );
2125         }
2126
2127         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2128         $profileMethod = $options['profileMethod'] ?? wfGetCaller();
2129
2130         try {
2131                 $result = Shell::command( [] )
2132                         ->unsafeParams( (array)$cmd )
2133                         ->environment( $environ )
2134                         ->limits( $limits )
2135                         ->includeStderr( $includeStderr )
2136                         ->profileMethod( $profileMethod )
2137                         // For b/c
2138                         ->restrict( Shell::RESTRICT_NONE )
2139                         ->execute();
2140         } catch ( ProcOpenError $ex ) {
2141                 $retval = -1;
2142                 return '';
2143         }
2144
2145         $retval = $result->getExitCode();
2146
2147         return $result->getStdout();
2148 }
2149
2150 /**
2151  * Execute a shell command, returning both stdout and stderr. Convenience
2152  * function, as all the arguments to wfShellExec can become unwieldy.
2153  *
2154  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2155  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2156  *   or an array of unescaped arguments, in which case each value will be escaped
2157  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2158  * @param null|mixed &$retval Optional, will receive the program's exit code.
2159  *   (non-zero is usually failure)
2160  * @param array $environ Optional environment variables which should be
2161  *   added to the executed command environment.
2162  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2163  *   this overwrites the global wgMaxShell* limits.
2164  * @return string Collected stdout and stderr as a string
2165  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2166  */
2167 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2168         return wfShellExec( $cmd, $retval, $environ, $limits,
2169                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2170 }
2171
2172 /**
2173  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2174  * Note that $parameters should be a flat array and an option with an argument
2175  * should consist of two consecutive items in the array (do not use "--option value").
2176  *
2177  * @deprecated since 1.31, use Shell::makeScriptCommand()
2178  *
2179  * @param string $script MediaWiki cli script path
2180  * @param array $parameters Arguments and options to the script
2181  * @param array $options Associative array of options:
2182  *     'php': The path to the php executable
2183  *     'wrapper': Path to a PHP wrapper to handle the maintenance script
2184  * @return string
2185  */
2186 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2187         global $wgPhpCli;
2188         // Give site config file a chance to run the script in a wrapper.
2189         // The caller may likely want to call wfBasename() on $script.
2190         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2191         $cmd = [ $options['php'] ?? $wgPhpCli ];
2192         if ( isset( $options['wrapper'] ) ) {
2193                 $cmd[] = $options['wrapper'];
2194         }
2195         $cmd[] = $script;
2196         // Escape each parameter for shell
2197         return Shell::escape( array_merge( $cmd, $parameters ) );
2198 }
2199
2200 /**
2201  * wfMerge attempts to merge differences between three texts.
2202  * Returns true for a clean merge and false for failure or a conflict.
2203  *
2204  * @param string $old
2205  * @param string $mine
2206  * @param string $yours
2207  * @param string &$result
2208  * @param string|null &$mergeAttemptResult
2209  * @return bool
2210  */
2211 function wfMerge( $old, $mine, $yours, &$result, &$mergeAttemptResult = null ) {
2212         global $wgDiff3;
2213
2214         # This check may also protect against code injection in
2215         # case of broken installations.
2216         AtEase::suppressWarnings();
2217         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2218         AtEase::restoreWarnings();
2219
2220         if ( !$haveDiff3 ) {
2221                 wfDebug( "diff3 not found\n" );
2222                 return false;
2223         }
2224
2225         # Make temporary files
2226         $td = wfTempDir();
2227         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2228         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2229         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2230
2231         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2232         #       a newline character. To avoid this, we normalize the trailing whitespace before
2233         #       creating the diff.
2234
2235         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2236         fclose( $oldtextFile );
2237         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2238         fclose( $mytextFile );
2239         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2240         fclose( $yourtextFile );
2241
2242         # Check for a conflict
2243         $cmd = Shell::escape( $wgDiff3, '-a', '--overlap-only', $mytextName,
2244                 $oldtextName, $yourtextName );
2245         $handle = popen( $cmd, 'r' );
2246
2247         $mergeAttemptResult = '';
2248         do {
2249                 $data = fread( $handle, 8192 );
2250                 if ( strlen( $data ) == 0 ) {
2251                         break;
2252                 }
2253                 $mergeAttemptResult .= $data;
2254         } while ( true );
2255         pclose( $handle );
2256
2257         $conflict = $mergeAttemptResult !== '';
2258
2259         # Merge differences
2260         $cmd = Shell::escape( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2261                 $oldtextName, $yourtextName );
2262         $handle = popen( $cmd, 'r' );
2263         $result = '';
2264         do {
2265                 $data = fread( $handle, 8192 );
2266                 if ( strlen( $data ) == 0 ) {
2267                         break;
2268                 }
2269                 $result .= $data;
2270         } while ( true );
2271         pclose( $handle );
2272         unlink( $mytextName );
2273         unlink( $oldtextName );
2274         unlink( $yourtextName );
2275
2276         if ( $result === '' && $old !== '' && !$conflict ) {
2277                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2278                 $conflict = true;
2279         }
2280         return !$conflict;
2281 }
2282
2283 /**
2284  * Returns unified plain-text diff of two texts.
2285  * "Useful" for machine processing of diffs.
2286  *
2287  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2288  *
2289  * @param string $before The text before the changes.
2290  * @param string $after The text after the changes.
2291  * @param string $params Command-line options for the diff command.
2292  * @return string Unified diff of $before and $after
2293  */
2294 function wfDiff( $before, $after, $params = '-u' ) {
2295         if ( $before == $after ) {
2296                 return '';
2297         }
2298
2299         global $wgDiff;
2300         AtEase::suppressWarnings();
2301         $haveDiff = $wgDiff && file_exists( $wgDiff );
2302         AtEase::restoreWarnings();
2303
2304         # This check may also protect against code injection in
2305         # case of broken installations.
2306         if ( !$haveDiff ) {
2307                 wfDebug( "diff executable not found\n" );
2308                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2309                 $format = new UnifiedDiffFormatter();
2310                 return $format->format( $diffs );
2311         }
2312
2313         # Make temporary files
2314         $td = wfTempDir();
2315         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2316         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2317
2318         fwrite( $oldtextFile, $before );
2319         fclose( $oldtextFile );
2320         fwrite( $newtextFile, $after );
2321         fclose( $newtextFile );
2322
2323         // Get the diff of the two files
2324         $cmd = "$wgDiff " . $params . ' ' . Shell::escape( $oldtextName, $newtextName );
2325
2326         $h = popen( $cmd, 'r' );
2327         if ( !$h ) {
2328                 unlink( $oldtextName );
2329                 unlink( $newtextName );
2330                 throw new Exception( __METHOD__ . '(): popen() failed' );
2331         }
2332
2333         $diff = '';
2334
2335         do {
2336                 $data = fread( $h, 8192 );
2337                 if ( strlen( $data ) == 0 ) {
2338                         break;
2339                 }
2340                 $diff .= $data;
2341         } while ( true );
2342
2343         // Clean up
2344         pclose( $h );
2345         unlink( $oldtextName );
2346         unlink( $newtextName );
2347
2348         // Kill the --- and +++ lines. They're not useful.
2349         $diff_lines = explode( "\n", $diff );
2350         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2351                 unset( $diff_lines[0] );
2352         }
2353         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2354                 unset( $diff_lines[1] );
2355         }
2356
2357         $diff = implode( "\n", $diff_lines );
2358
2359         return $diff;
2360 }
2361
2362 /**
2363  * Return the final portion of a pathname.
2364  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2365  * https://bugs.php.net/bug.php?id=33898
2366  *
2367  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2368  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2369  *
2370  * @param string $path
2371  * @param string $suffix String to remove if present
2372  * @return string
2373  */
2374 function wfBaseName( $path, $suffix = '' ) {
2375         if ( $suffix == '' ) {
2376                 $encSuffix = '';
2377         } else {
2378                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2379         }
2380
2381         $matches = [];
2382         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2383                 return $matches[1];
2384         } else {
2385                 return '';
2386         }
2387 }
2388
2389 /**
2390  * Generate a relative path name to the given file.
2391  * May explode on non-matching case-insensitive paths,
2392  * funky symlinks, etc.
2393  *
2394  * @param string $path Absolute destination path including target filename
2395  * @param string $from Absolute source path, directory only
2396  * @return string
2397  */
2398 function wfRelativePath( $path, $from ) {
2399         // Normalize mixed input on Windows...
2400         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2401         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2402
2403         // Trim trailing slashes -- fix for drive root
2404         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2405         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2406
2407         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2408         $against = explode( DIRECTORY_SEPARATOR, $from );
2409
2410         if ( $pieces[0] !== $against[0] ) {
2411                 // Non-matching Windows drive letters?
2412                 // Return a full path.
2413                 return $path;
2414         }
2415
2416         // Trim off common prefix
2417         while ( count( $pieces ) && count( $against )
2418                 && $pieces[0] == $against[0] ) {
2419                 array_shift( $pieces );
2420                 array_shift( $against );
2421         }
2422
2423         // relative dots to bump us to the parent
2424         while ( count( $against ) ) {
2425                 array_unshift( $pieces, '..' );
2426                 array_shift( $against );
2427         }
2428
2429         array_push( $pieces, wfBaseName( $path ) );
2430
2431         return implode( DIRECTORY_SEPARATOR, $pieces );
2432 }
2433
2434 /**
2435  * Reset the session id
2436  *
2437  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2438  * @since 1.22
2439  */
2440 function wfResetSessionID() {
2441         wfDeprecated( __FUNCTION__, '1.27' );
2442         $session = SessionManager::getGlobalSession();
2443         $delay = $session->delaySave();
2444
2445         $session->resetId();
2446
2447         // Make sure a session is started, since that's what the old
2448         // wfResetSessionID() did.
2449         if ( session_id() !== $session->getId() ) {
2450                 wfSetupSession( $session->getId() );
2451         }
2452
2453         ScopedCallback::consume( $delay );
2454 }
2455
2456 /**
2457  * Initialise php session
2458  *
2459  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2460  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2461  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2462  *  here), then calling $session->persist().
2463  * @param bool|string $sessionId
2464  */
2465 function wfSetupSession( $sessionId = false ) {
2466         wfDeprecated( __FUNCTION__, '1.27' );
2467
2468         if ( $sessionId ) {
2469                 session_id( $sessionId );
2470         }
2471
2472         $session = SessionManager::getGlobalSession();
2473         $session->persist();
2474
2475         if ( session_id() !== $session->getId() ) {
2476                 session_id( $session->getId() );
2477         }
2478         AtEase::quietCall( 'session_start' );
2479 }
2480
2481 /**
2482  * Get an object from the precompiled serialized directory
2483  *
2484  * @param string $name
2485  * @return mixed The variable on success, false on failure
2486  */
2487 function wfGetPrecompiledData( $name ) {
2488         global $IP;
2489
2490         $file = "$IP/serialized/$name";
2491         if ( file_exists( $file ) ) {
2492                 $blob = file_get_contents( $file );
2493                 if ( $blob ) {
2494                         return unserialize( $blob );
2495                 }
2496         }
2497         return false;
2498 }
2499
2500 /**
2501  * Make a cache key for the local wiki.
2502  *
2503  * @deprecated since 1.30 Call makeKey on a BagOStuff instance
2504  * @param string ...$args
2505  * @return string
2506  */
2507 function wfMemcKey( ...$args ) {
2508         return ObjectCache::getLocalClusterInstance()->makeKey( ...$args );
2509 }
2510
2511 /**
2512  * Make a cache key for a foreign DB.
2513  *
2514  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2515  *
2516  * @param string $db
2517  * @param string $prefix
2518  * @param string ...$args
2519  * @return string
2520  */
2521 function wfForeignMemcKey( $db, $prefix, ...$args ) {
2522         $keyspace = $prefix ? "$db-$prefix" : $db;
2523         return ObjectCache::getLocalClusterInstance()->makeKeyInternal( $keyspace, $args );
2524 }
2525
2526 /**
2527  * Make a cache key with database-agnostic prefix.
2528  *
2529  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
2530  * instead. Must have a prefix as otherwise keys that use a database name
2531  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
2532  *
2533  * @deprecated since 1.30 Call makeGlobalKey on a BagOStuff instance
2534  * @since 1.26
2535  * @param string ...$args
2536  * @return string
2537  */
2538 function wfGlobalCacheKey( ...$args ) {
2539         return ObjectCache::getLocalClusterInstance()->makeGlobalKey( ...$args );
2540 }
2541
2542 /**
2543  * Get an ASCII string identifying this wiki
2544  * This is used as a prefix in memcached keys
2545  *
2546  * @return string
2547  */
2548 function wfWikiID() {
2549         global $wgDBprefix, $wgDBname;
2550         if ( $wgDBprefix ) {
2551                 return "$wgDBname-$wgDBprefix";
2552         } else {
2553                 return $wgDBname;
2554         }
2555 }
2556
2557 /**
2558  * Get a Database object.
2559  *
2560  * @param int $db Index of the connection to get. May be DB_MASTER for the
2561  *            master (for write queries), DB_REPLICA for potentially lagged read
2562  *            queries, or an integer >= 0 for a particular server.
2563  *
2564  * @param string|string[] $groups Query groups. An array of group names that this query
2565  *                belongs to. May contain a single string if the query is only
2566  *                in one group.
2567  *
2568  * @param string|bool $wiki The wiki ID, or false for the current wiki
2569  *
2570  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
2571  * will always return the same object, unless the underlying connection or load
2572  * balancer is manually destroyed.
2573  *
2574  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
2575  * updater to ensure that a proper database is being updated.
2576  *
2577  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
2578  *       on an injected instance of LoadBalancer.
2579  *
2580  * @return \Wikimedia\Rdbms\Database
2581  */
2582 function wfGetDB( $db, $groups = [], $wiki = false ) {
2583         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
2584 }
2585
2586 /**
2587  * Get a load balancer object.
2588  *
2589  * @deprecated since 1.27, use MediaWikiServices::getInstance()->getDBLoadBalancer()
2590  *              or MediaWikiServices::getInstance()->getDBLoadBalancerFactory() instead.
2591  *
2592  * @param string|bool $wiki Wiki ID, or false for the current wiki
2593  * @return \Wikimedia\Rdbms\LoadBalancer
2594  */
2595 function wfGetLB( $wiki = false ) {
2596         if ( $wiki === false ) {
2597                 return MediaWikiServices::getInstance()->getDBLoadBalancer();
2598         } else {
2599                 $factory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2600                 return $factory->getMainLB( $wiki );
2601         }
2602 }
2603
2604 /**
2605  * Get the load balancer factory object
2606  *
2607  * @deprecated since 1.27, use MediaWikiServices::getInstance()->getDBLoadBalancerFactory() instead.
2608  * TODO: Remove in MediaWiki 1.35
2609  *
2610  * @return \Wikimedia\Rdbms\LBFactory
2611  */
2612 function wfGetLBFactory() {
2613         wfDeprecated( __METHOD__, '1.27' );
2614         return MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2615 }
2616
2617 /**
2618  * Find a file.
2619  * @deprecated since 1.34, use MediaWikiServices
2620  * @param string|LinkTarget $title String or LinkTarget object
2621  * @param array $options Associative array of options (see RepoGroup::findFile)
2622  * @return File|bool File, or false if the file does not exist
2623  */
2624 function wfFindFile( $title, $options = [] ) {
2625         return MediaWikiServices::getInstance()->getRepoGroup()->findFile( $title, $options );
2626 }
2627
2628 /**
2629  * Get an object referring to a locally registered file.
2630  * Returns a valid placeholder object if the file does not exist.
2631  *
2632  * @deprecated since 1.34, use MediaWikiServices
2633  * @param Title|string $title
2634  * @return LocalFile|null A File, or null if passed an invalid Title
2635  */
2636 function wfLocalFile( $title ) {
2637         return MediaWikiServices::getInstance()->getRepoGroup()->getLocalRepo()->newFile( $title );
2638 }
2639
2640 /**
2641  * Should low-performance queries be disabled?
2642  *
2643  * @return bool
2644  * @codeCoverageIgnore
2645  */
2646 function wfQueriesMustScale() {
2647         global $wgMiserMode;
2648         return $wgMiserMode
2649                 || ( SiteStats::pages() > 100000
2650                 && SiteStats::edits() > 1000000
2651                 && SiteStats::users() > 10000 );
2652 }
2653
2654 /**
2655  * Get the path to a specified script file, respecting file
2656  * extensions; this is a wrapper around $wgScriptPath etc.
2657  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
2658  *
2659  * @param string $script Script filename, sans extension
2660  * @return string
2661  */
2662 function wfScript( $script = 'index' ) {
2663         global $wgScriptPath, $wgScript, $wgLoadScript;
2664         if ( $script === 'index' ) {
2665                 return $wgScript;
2666         } elseif ( $script === 'load' ) {
2667                 return $wgLoadScript;
2668         } else {
2669                 return "{$wgScriptPath}/{$script}.php";
2670         }
2671 }
2672
2673 /**
2674  * Get the script URL.
2675  *
2676  * @return string Script URL
2677  */
2678 function wfGetScriptUrl() {
2679         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
2680                 /* as it was called, minus the query string.
2681                  *
2682                  * Some sites use Apache rewrite rules to handle subdomains,
2683                  * and have PHP set up in a weird way that causes PHP_SELF
2684                  * to contain the rewritten URL instead of the one that the
2685                  * outside world sees.
2686                  *
2687                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
2688                  * provides containing the "before" URL.
2689                  */
2690                 return $_SERVER['SCRIPT_NAME'];
2691         } else {
2692                 return $_SERVER['URL'];
2693         }
2694 }
2695
2696 /**
2697  * Convenience function converts boolean values into "true"
2698  * or "false" (string) values
2699  *
2700  * @param bool $value
2701  * @return string
2702  */
2703 function wfBoolToStr( $value ) {
2704         return $value ? 'true' : 'false';
2705 }
2706
2707 /**
2708  * Get a platform-independent path to the null file, e.g. /dev/null
2709  *
2710  * @return string
2711  */
2712 function wfGetNull() {
2713         return wfIsWindows() ? 'NUL' : '/dev/null';
2714 }
2715
2716 /**
2717  * Waits for the replica DBs to catch up to the master position
2718  *
2719  * Use this when updating very large numbers of rows, as in maintenance scripts,
2720  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
2721  *
2722  * By default this waits on the main DB cluster of the current wiki.
2723  * If $cluster is set to "*" it will wait on all DB clusters, including
2724  * external ones. If the lag being waiting on is caused by the code that
2725  * does this check, it makes since to use $ifWritesSince, particularly if
2726  * cluster is "*", to avoid excess overhead.
2727  *
2728  * Never call this function after a big DB write that is still in a transaction.
2729  * This only makes sense after the possible lag inducing changes were committed.
2730  *
2731  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
2732  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
2733  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
2734  * @param int|null $timeout Max wait time. Default: 60 seconds (cli), 1 second (web)
2735  * @return bool Success (able to connect and no timeouts reached)
2736  * @deprecated since 1.27 Use LBFactory::waitForReplication
2737  */
2738 function wfWaitForSlaves(
2739         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
2740 ) {
2741         $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2742
2743         if ( $cluster === '*' ) {
2744                 $cluster = false;
2745                 $domain = false;
2746         } elseif ( $wiki === false ) {
2747                 $domain = $lbFactory->getLocalDomainID();
2748         } else {
2749                 $domain = $wiki;
2750         }
2751
2752         $opts = [
2753                 'domain' => $domain,
2754                 'cluster' => $cluster,
2755                 // B/C: first argument used to be "max seconds of lag"; ignore such values
2756                 'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
2757         ];
2758         if ( $timeout !== null ) {
2759                 $opts['timeout'] = $timeout;
2760         }
2761
2762         return $lbFactory->waitForReplication( $opts );
2763 }
2764
2765 /**
2766  * Count down from $seconds to zero on the terminal, with a one-second pause
2767  * between showing each number. For use in command-line scripts.
2768  *
2769  * @deprecated since 1.31, use Maintenance::countDown()
2770  *
2771  * @codeCoverageIgnore
2772  * @param int $seconds
2773  */
2774 function wfCountDown( $seconds ) {
2775         wfDeprecated( __FUNCTION__, '1.31' );
2776         for ( $i = $seconds; $i >= 0; $i-- ) {
2777                 if ( $i != $seconds ) {
2778                         echo str_repeat( "\x08", strlen( $i + 1 ) );
2779                 }
2780                 echo $i;
2781                 flush();
2782                 if ( $i ) {
2783                         sleep( 1 );
2784                 }
2785         }
2786         echo "\n";
2787 }
2788
2789 /**
2790  * Replace all invalid characters with '-'.
2791  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
2792  * By default, $wgIllegalFileChars includes ':', '/', '\'.
2793  *
2794  * @param string $name Filename to process
2795  * @return string
2796  */
2797 function wfStripIllegalFilenameChars( $name ) {
2798         global $wgIllegalFileChars;
2799         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
2800         $name = preg_replace(
2801                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
2802                 '-',
2803                 $name
2804         );
2805         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
2806         $name = wfBaseName( $name );
2807         return $name;
2808 }
2809
2810 /**
2811  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
2812  *
2813  * @return int Resulting value of the memory limit.
2814  */
2815 function wfMemoryLimit() {
2816         global $wgMemoryLimit;
2817         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
2818         if ( $memlimit != -1 ) {
2819                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
2820                 if ( $conflimit == -1 ) {
2821                         wfDebug( "Removing PHP's memory limit\n" );
2822                         Wikimedia\suppressWarnings();
2823                         ini_set( 'memory_limit', $conflimit );
2824                         Wikimedia\restoreWarnings();
2825                         return $conflimit;
2826                 } elseif ( $conflimit > $memlimit ) {
2827                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
2828                         Wikimedia\suppressWarnings();
2829                         ini_set( 'memory_limit', $conflimit );
2830                         Wikimedia\restoreWarnings();
2831                         return $conflimit;
2832                 }
2833         }
2834         return $memlimit;
2835 }
2836
2837 /**
2838  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
2839  *
2840  * @return int Prior time limit
2841  * @since 1.26
2842  */
2843 function wfTransactionalTimeLimit() {
2844         global $wgTransactionalTimeLimit;
2845
2846         $timeLimit = ini_get( 'max_execution_time' );
2847         // Note that CLI scripts use 0
2848         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
2849                 set_time_limit( $wgTransactionalTimeLimit );
2850         }
2851
2852         ignore_user_abort( true ); // ignore client disconnects
2853
2854         return $timeLimit;
2855 }
2856
2857 /**
2858  * Converts shorthand byte notation to integer form
2859  *
2860  * @param string $string
2861  * @param int $default Returned if $string is empty
2862  * @return int
2863  */
2864 function wfShorthandToInteger( $string = '', $default = -1 ) {
2865         $string = trim( $string );
2866         if ( $string === '' ) {
2867                 return $default;
2868         }
2869         $last = $string[strlen( $string ) - 1];
2870         $val = intval( $string );
2871         switch ( $last ) {
2872                 case 'g':
2873                 case 'G':
2874                         $val *= 1024;
2875                         // break intentionally missing
2876                 case 'm':
2877                 case 'M':
2878                         $val *= 1024;
2879                         // break intentionally missing
2880                 case 'k':
2881                 case 'K':
2882                         $val *= 1024;
2883         }
2884
2885         return $val;
2886 }
2887
2888 /**
2889  * Get the normalised IETF language tag
2890  * See unit test for examples.
2891  * See mediawiki.language.bcp47 for the JavaScript implementation.
2892  *
2893  * @deprecated since 1.31, use LanguageCode::bcp47() directly.
2894  *
2895  * @param string $code The language code.
2896  * @return string The language code which complying with BCP 47 standards.
2897  */
2898 function wfBCP47( $code ) {
2899         wfDeprecated( __METHOD__, '1.31' );
2900         return LanguageCode::bcp47( $code );
2901 }
2902
2903 /**
2904  * Get a specific cache object.
2905  *
2906  * @deprecated since 1.32, use ObjectCache::getInstance() instead
2907  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
2908  * @return BagOStuff
2909  */
2910 function wfGetCache( $cacheType ) {
2911         return ObjectCache::getInstance( $cacheType );
2912 }
2913
2914 /**
2915  * Get the main cache object
2916  *
2917  * @deprecated since 1.32, use ObjectCache::getLocalClusterInstance() instead
2918  * @return BagOStuff
2919  */
2920 function wfGetMainCache() {
2921         return ObjectCache::getLocalClusterInstance();
2922 }
2923
2924 /**
2925  * Get the cache object used by the message cache
2926  *
2927  * @return BagOStuff
2928  */
2929 function wfGetMessageCacheStorage() {
2930         global $wgMessageCacheType;
2931         return ObjectCache::getInstance( $wgMessageCacheType );
2932 }
2933
2934 /**
2935  * Wrapper around php's unpack.
2936  *
2937  * @param string $format The format string (See php's docs)
2938  * @param string $data A binary string of binary data
2939  * @param int|bool $length The minimum length of $data or false. This is to
2940  *      prevent reading beyond the end of $data. false to disable the check.
2941  *
2942  * Also be careful when using this function to read unsigned 32 bit integer
2943  * because php might make it negative.
2944  *
2945  * @throws MWException If $data not long enough, or if unpack fails
2946  * @return array Associative array of the extracted data
2947  */
2948 function wfUnpack( $format, $data, $length = false ) {
2949         if ( $length !== false ) {
2950                 $realLen = strlen( $data );
2951                 if ( $realLen < $length ) {
2952                         throw new MWException( "Tried to use wfUnpack on a "
2953                                 . "string of length $realLen, but needed one "
2954                                 . "of at least length $length."
2955                         );
2956                 }
2957         }
2958
2959         Wikimedia\suppressWarnings();
2960         $result = unpack( $format, $data );
2961         Wikimedia\restoreWarnings();
2962
2963         if ( $result === false ) {
2964                 // If it cannot extract the packed data.
2965                 throw new MWException( "unpack could not unpack binary data" );
2966         }
2967         return $result;
2968 }
2969
2970 /**
2971  * Determine if an image exists on the 'bad image list'.
2972  *
2973  * The format of MediaWiki:Bad_image_list is as follows:
2974  *    * Only list items (lines starting with "*") are considered
2975  *    * The first link on a line must be a link to a bad image
2976  *    * Any subsequent links on the same line are considered to be exceptions,
2977  *      i.e. articles where the image may occur inline.
2978  *
2979  * @param string $name The image name to check
2980  * @param Title|bool $contextTitle The page on which the image occurs, if known
2981  * @param string|null $blacklist Wikitext of a file blacklist
2982  * @return bool
2983  */
2984 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
2985         # Handle redirects; callers almost always hit wfFindFile() anyway,
2986         # so just use that method because it has a fast process cache.
2987         $file = wfFindFile( $name ); // get the final name
2988         $name = $file ? $file->getTitle()->getDBkey() : $name;
2989
2990         # Run the extension hook
2991         $bad = false;
2992         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
2993                 return (bool)$bad;
2994         }
2995
2996         $cache = ObjectCache::getLocalServerInstance( 'hash' );
2997         $key = $cache->makeKey(
2998                 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist )
2999         );
3000         $badImages = $cache->get( $key );
3001
3002         if ( $badImages === false ) { // cache miss
3003                 if ( $blacklist === null ) {
3004                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3005                 }
3006                 # Build the list now
3007                 $badImages = [];
3008                 $lines = explode( "\n", $blacklist );
3009                 foreach ( $lines as $line ) {
3010                         # List items only
3011                         if ( substr( $line, 0, 1 ) !== '*' ) {
3012                                 continue;
3013                         }
3014
3015                         # Find all links
3016                         $m = [];
3017                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3018                                 continue;
3019                         }
3020
3021                         $exceptions = [];
3022                         $imageDBkey = false;
3023                         foreach ( $m[1] as $i => $titleText ) {
3024                                 $title = Title::newFromText( $titleText );
3025                                 if ( !is_null( $title ) ) {
3026                                         if ( $i == 0 ) {
3027                                                 $imageDBkey = $title->getDBkey();
3028                                         } else {
3029                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3030                                         }
3031                                 }
3032                         }
3033
3034                         if ( $imageDBkey !== false ) {
3035                                 $badImages[$imageDBkey] = $exceptions;
3036                         }
3037                 }
3038                 $cache->set( $key, $badImages, 60 );
3039         }
3040
3041         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3042         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3043
3044         return $bad;
3045 }
3046
3047 /**
3048  * Determine whether the client at a given source IP is likely to be able to
3049  * access the wiki via HTTPS.
3050  *
3051  * @param string $ip The IPv4/6 address in the normal human-readable form
3052  * @return bool
3053  */
3054 function wfCanIPUseHTTPS( $ip ) {
3055         $canDo = true;
3056         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3057         return (bool)$canDo;
3058 }
3059
3060 /**
3061  * Determine input string is represents as infinity
3062  *
3063  * @param string $str The string to determine
3064  * @return bool
3065  * @since 1.25
3066  */
3067 function wfIsInfinity( $str ) {
3068         // These are hardcoded elsewhere in MediaWiki (e.g. mediawiki.special.block.js).
3069         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3070         return in_array( $str, $infinityValues );
3071 }
3072
3073 /**
3074  * Returns true if these thumbnail parameters match one that MediaWiki
3075  * requests from file description pages and/or parser output.
3076  *
3077  * $params is considered non-standard if they involve a non-standard
3078  * width or any non-default parameters aside from width and page number.
3079  * The number of possible files with standard parameters is far less than
3080  * that of all combinations; rate-limiting for them can thus be more generious.
3081  *
3082  * @param File $file
3083  * @param array $params
3084  * @return bool
3085  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3086  */
3087 function wfThumbIsStandard( File $file, array $params ) {
3088         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3089
3090         $multipliers = [ 1 ];
3091         if ( $wgResponsiveImages ) {
3092                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3093                 // @see Linker::processResponsiveImages
3094                 $multipliers[] = 1.5;
3095                 $multipliers[] = 2;
3096         }
3097
3098         $handler = $file->getHandler();
3099         if ( !$handler || !isset( $params['width'] ) ) {
3100                 return false;
3101         }
3102
3103         $basicParams = [];
3104         if ( isset( $params['page'] ) ) {
3105                 $basicParams['page'] = $params['page'];
3106         }
3107
3108         $thumbLimits = [];
3109         $imageLimits = [];
3110         // Expand limits to account for multipliers
3111         foreach ( $multipliers as $multiplier ) {
3112                 $thumbLimits = array_merge( $thumbLimits, array_map(
3113                         function ( $width ) use ( $multiplier ) {
3114                                 return round( $width * $multiplier );
3115                         }, $wgThumbLimits )
3116                 );
3117                 $imageLimits = array_merge( $imageLimits, array_map(
3118                         function ( $pair ) use ( $multiplier ) {
3119                                 return [
3120                                         round( $pair[0] * $multiplier ),
3121                                         round( $pair[1] * $multiplier ),
3122                                 ];
3123                         }, $wgImageLimits )
3124                 );
3125         }
3126
3127         // Check if the width matches one of $wgThumbLimits
3128         if ( in_array( $params['width'], $thumbLimits ) ) {
3129                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3130                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3131                 $handler->normaliseParams( $file, $normalParams );
3132         } else {
3133                 // If not, then check if the width matchs one of $wgImageLimits
3134                 $match = false;
3135                 foreach ( $imageLimits as $pair ) {
3136                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3137                         // Decide whether the thumbnail should be scaled on width or height.
3138                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3139                         $handler->normaliseParams( $file, $normalParams );
3140                         // Check if this standard thumbnail size maps to the given width
3141                         if ( $normalParams['width'] == $params['width'] ) {
3142                                 $match = true;
3143                                 break;
3144                         }
3145                 }
3146                 if ( !$match ) {
3147                         return false; // not standard for description pages
3148                 }
3149         }
3150
3151         // Check that the given values for non-page, non-width, params are just defaults
3152         foreach ( $params as $key => $value ) {
3153                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3154                         return false;
3155                 }
3156         }
3157
3158         return true;
3159 }
3160
3161 /**
3162  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3163  *
3164  * Values that exist in both values will be combined with += (all values of the array
3165  * of $newValues will be added to the values of the array of $baseArray, while values,
3166  * that exists in both, the value of $baseArray will be used).
3167  *
3168  * @param array $baseArray The array where you want to add the values of $newValues to
3169  * @param array $newValues An array with new values
3170  * @return array The combined array
3171  * @since 1.26
3172  */
3173 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3174         // First merge items that are in both arrays
3175         foreach ( $baseArray as $name => &$groupVal ) {
3176                 if ( isset( $newValues[$name] ) ) {
3177                         $groupVal += $newValues[$name];
3178                 }
3179         }
3180         // Now add items that didn't exist yet
3181         $baseArray += $newValues;
3182
3183         return $baseArray;
3184 }
3185
3186 /**
3187  * Get system resource usage of current request context.
3188  * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
3189  * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
3190  *
3191  * @since 1.24
3192  * @return array|bool Resource usage data or false if no data available.
3193  */
3194 function wfGetRusage() {
3195         if ( !function_exists( 'getrusage' ) ) {
3196                 return false;
3197         } elseif ( defined( 'HHVM_VERSION' ) && PHP_OS === 'Linux' ) {
3198                 return getrusage( 2 /* RUSAGE_THREAD */ );
3199         } else {
3200                 return getrusage( 0 /* RUSAGE_SELF */ );
3201         }
3202 }