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
  36 /**
  37  * Load an extension
  38  *
  39  * This queues an extension to be loaded through
  40  * the ExtensionRegistry system.
  41  *
  42  * @param string $ext Name of the extension to load
  43  * @param string|null $path Absolute path of where to find the extension.json file
  44  * @since 1.25
  45  */
  46 function wfLoadExtension( $ext, $path = null ) {
  47         if ( !$path ) {
  48                 global $wgExtensionDirectory;
  49                 $path = "$wgExtensionDirectory/$ext/extension.json";
  50         }
  51         ExtensionRegistry::getInstance()->queue( $path );
  52 }
  53
  54 /**
  55  * Load multiple extensions at once
  56  *
  57  * Same as wfLoadExtension, but more efficient if you
  58  * are loading multiple extensions.
  59  *
  60  * If you want to specify custom paths, you should interact with
  61  * ExtensionRegistry directly.
  62  *
  63  * @see wfLoadExtension
  64  * @param string[] $exts Array of extension names to load
  65  * @since 1.25
  66  */
  67 function wfLoadExtensions( array $exts ) {
  68         global $wgExtensionDirectory;
  69         $registry = ExtensionRegistry::getInstance();
  70         foreach ( $exts as $ext ) {
  71                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
  72         }
  73 }
  74
  75 /**
  76  * Load a skin
  77  *
  78  * @see wfLoadExtension
  79  * @param string $skin Name of the extension to load
  80  * @param string|null $path Absolute path of where to find the skin.json file
  81  * @since 1.25
  82  */
  83 function wfLoadSkin( $skin, $path = null ) {
  84         if ( !$path ) {
  85                 global $wgStyleDirectory;
  86                 $path = "$wgStyleDirectory/$skin/skin.json";
  87         }
  88         ExtensionRegistry::getInstance()->queue( $path );
  89 }
  90
  91 /**
  92  * Load multiple skins at once
  93  *
  94  * @see wfLoadExtensions
  95  * @param string[] $skins Array of extension names to load
  96  * @since 1.25
  97  */
  98 function wfLoadSkins( array $skins ) {
  99         global $wgStyleDirectory;
 100         $registry = ExtensionRegistry::getInstance();
 101         foreach ( $skins as $skin ) {
 102                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 103         }
 104 }
 105
 106 /**
 107  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 108  * @param array $a
 109  * @param array $b
 110  * @return array
 111  */
 112 function wfArrayDiff2( $a, $b ) {
 113         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 114 }
 115
 116 /**
 117  * @param array|string $a
 118  * @param array|string $b
 119  * @return int
 120  */
 121 function wfArrayDiff2_cmp( $a, $b ) {
 122         if ( is_string( $a ) && is_string( $b ) ) {
 123                 return strcmp( $a, $b );
 124         } elseif ( count( $a ) !== count( $b ) ) {
 125                 return count( $a ) <=> count( $b );
 126         } else {
 127                 reset( $a );
 128                 reset( $b );
 129                 while ( key( $a ) !== null && key( $b ) !== null ) {
 130                         $valueA = current( $a );
 131                         $valueB = current( $b );
 132                         $cmp = strcmp( $valueA, $valueB );
 133                         if ( $cmp !== 0 ) {
 134                                 return $cmp;
 135                         }
 136                         next( $a );
 137                         next( $b );
 138                 }
 139                 return 0;
 140         }
 141 }
 142
 143 /**
 144  * Appends to second array if $value differs from that in $default
 145  *
 146  * @param string|int $key
 147  * @param mixed $value
 148  * @param mixed $default
 149  * @param array &$changed Array to alter
 150  * @throws MWException
 151  */
 152 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 153         if ( is_null( $changed ) ) {
 154                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 155         }
 156         if ( $default[$key] !== $value ) {
 157                 $changed[$key] = $value;
 158         }
 159 }
 160
 161 /**
 162  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 163  * e.g.
 164  *     wfMergeErrorArrays(
 165  *       [ [ 'x' ] ],
 166  *       [ [ 'x', '2' ] ],
 167  *       [ [ 'x' ] ],
 168  *       [ [ 'y' ] ]
 169  *     );
 170  * returns:
 171  *     [
 172  *       [ 'x', '2' ],
 173  *       [ 'x' ],
 174  *       [ 'y' ]
 175  *     ]
 176  *
 177  * @param array ...$args
 178  * @return array
 179  */
 180 function wfMergeErrorArrays( ...$args ) {
 181         $out = [];
 182         foreach ( $args as $errors ) {
 183                 foreach ( $errors as $params ) {
 184                         $originalParams = $params;
 185                         if ( $params[0] instanceof MessageSpecifier ) {
 186                                 $msg = $params[0];
 187                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 188                         }
 189                         # @todo FIXME: Sometimes get nested arrays for $params,
 190                         # which leads to E_NOTICEs
 191                         $spec = implode( "\t", $params );
 192                         $out[$spec] = $originalParams;
 193                 }
 194         }
 195         return array_values( $out );
 196 }
 197
 198 /**
 199  * Insert array into another array after the specified *KEY*
 200  *
 201  * @param array $array The array.
 202  * @param array $insert The array to insert.
 203  * @param mixed $after The key to insert after. Callers need to make sure the key is set.
 204  * @return array
 205  */
 206 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 207         // Find the offset of the element to insert after.
 208         $keys = array_keys( $array );
 209         $offsetByKey = array_flip( $keys );
 210
 211         $offset = $offsetByKey[$after];
 212
 213         // Insert at the specified offset
 214         $before = array_slice( $array, 0, $offset + 1, true );
 215         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 216
 217         $output = $before + $insert + $after;
 218
 219         return $output;
 220 }
 221
 222 /**
 223  * Recursively converts the parameter (an object) to an array with the same data
 224  *
 225  * @param object|array $objOrArray
 226  * @param bool $recursive
 227  * @return array
 228  */
 229 function wfObjectToArray( $objOrArray, $recursive = true ) {
 230         $array = [];
 231         if ( is_object( $objOrArray ) ) {
 232                 $objOrArray = get_object_vars( $objOrArray );
 233         }
 234         foreach ( $objOrArray as $key => $value ) {
 235                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 236                         $value = wfObjectToArray( $value );
 237                 }
 238
 239                 $array[$key] = $value;
 240         }
 241
 242         return $array;
 243 }
 244
 245 /**
 246  * Get a random decimal value in the domain of [0, 1), in a way
 247  * not likely to give duplicate values for any realistic
 248  * number of articles.
 249  *
 250  * @note This is designed for use in relation to Special:RandomPage
 251  *       and the page_random database field.
 252  *
 253  * @return string
 254  */
 255 function wfRandom() {
 256         // The maximum random value is "only" 2^31-1, so get two random
 257         // values to reduce the chance of dupes
 258         $max = mt_getrandmax() + 1;
 259         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 260         return $rand;
 261 }
 262
 263 /**
 264  * Get a random string containing a number of pseudo-random hex characters.
 265  *
 266  * @note This is not secure, if you are trying to generate some sort
 267  *       of token please use MWCryptRand instead.
 268  *
 269  * @param int $length The length of the string to generate
 270  * @return string
 271  * @since 1.20
 272  */
 273 function wfRandomString( $length = 32 ) {
 274         $str = '';
 275         for ( $n = 0; $n < $length; $n += 7 ) {
 276                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 277         }
 278         return substr( $str, 0, $length );
 279 }
 280
 281 /**
 282  * We want some things to be included as literal characters in our title URLs
 283  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 284  * all of the following should be safe:
 285  *
 286  * ;:@&=$-_.+!*'(),
 287  *
 288  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 289  * character which should not be encoded. More importantly, google chrome
 290  * always converts %7E back to ~, and converting it in this function can
 291  * cause a redirect loop (T105265).
 292  *
 293  * But + is not safe because it's used to indicate a space; &= are only safe in
 294  * paths and not in queries (and we don't distinguish here); ' seems kind of
 295  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 296  * is reserved, we don't care.  So the list we unescape is:
 297  *
 298  * ;:@$!*(),/~
 299  *
 300  * However, IIS7 redirects fail when the url contains a colon (see T24709),
 301  * so no fancy : for IIS7.
 302  *
 303  * %2F in the page titles seems to fatally break for some reason.
 304  *
 305  * @param string $s
 306  * @return string
 307  */
 308 function wfUrlencode( $s ) {
 309         static $needle;
 310
 311         if ( is_null( $s ) ) {
 312                 // Reset $needle for testing.
 313                 $needle = null;
 314                 return '';
 315         }
 316
 317         if ( is_null( $needle ) ) {
 318                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 319                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 320                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 321                 ) {
 322                         $needle[] = '%3A';
 323                 }
 324         }
 325
 326         $s = urlencode( $s );
 327         $s = str_ireplace(
 328                 $needle,
 329                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 330                 $s
 331         );
 332
 333         return $s;
 334 }
 335
 336 /**
 337  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 338  * "days=7&limit=100". Options in the first array override options in the second.
 339  * Options set to null or false will not be output.
 340  *
 341  * @param array $array1 ( String|Array )
 342  * @param array|null $array2 ( String|Array )
 343  * @param string $prefix
 344  * @return string
 345  */
 346 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 347         if ( !is_null( $array2 ) ) {
 348                 $array1 = $array1 + $array2;
 349         }
 350
 351         $cgi = '';
 352         foreach ( $array1 as $key => $value ) {
 353                 if ( !is_null( $value ) && $value !== false ) {
 354                         if ( $cgi != '' ) {
 355                                 $cgi .= '&';
 356                         }
 357                         if ( $prefix !== '' ) {
 358                                 $key = $prefix . "[$key]";
 359                         }
 360                         if ( is_array( $value ) ) {
 361                                 $firstTime = true;
 362                                 foreach ( $value as $k => $v ) {
 363                                         $cgi .= $firstTime ? '' : '&';
 364                                         if ( is_array( $v ) ) {
 365                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 366                                         } else {
 367                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 368                                         }
 369                                         $firstTime = false;
 370                                 }
 371                         } else {
 372                                 if ( is_object( $value ) ) {
 373                                         $value = $value->__toString();
 374                                 }
 375                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 376                         }
 377                 }
 378         }
 379         return $cgi;
 380 }
 381
 382 /**
 383  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 384  * its argument and returns the same string in array form.  This allows compatibility
 385  * with legacy functions that accept raw query strings instead of nice
 386  * arrays.  Of course, keys and values are urldecode()d.
 387  *
 388  * @param string $query Query string
 389  * @return string[] Array version of input
 390  */
 391 function wfCgiToArray( $query ) {
 392         if ( isset( $query[0] ) && $query[0] == '?' ) {
 393                 $query = substr( $query, 1 );
 394         }
 395         $bits = explode( '&', $query );
 396         $ret = [];
 397         foreach ( $bits as $bit ) {
 398                 if ( $bit === '' ) {
 399                         continue;
 400                 }
 401                 if ( strpos( $bit, '=' ) === false ) {
 402                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 403                         $key = $bit;
 404                         $value = '';
 405                 } else {
 406                         list( $key, $value ) = explode( '=', $bit );
 407                 }
 408                 $key = urldecode( $key );
 409                 $value = urldecode( $value );
 410                 if ( strpos( $key, '[' ) !== false ) {
 411                         $keys = array_reverse( explode( '[', $key ) );
 412                         $key = array_pop( $keys );
 413                         $temp = $value;
 414                         foreach ( $keys as $k ) {
 415                                 $k = substr( $k, 0, -1 );
 416                                 $temp = [ $k => $temp ];
 417                         }
 418                         if ( isset( $ret[$key] ) ) {
 419                                 $ret[$key] = array_merge( $ret[$key], $temp );
 420                         } else {
 421                                 $ret[$key] = $temp;
 422                         }
 423                 } else {
 424                         $ret[$key] = $value;
 425                 }
 426         }
 427         return $ret;
 428 }
 429
 430 /**
 431  * Append a query string to an existing URL, which may or may not already
 432  * have query string parameters already. If so, they will be combined.
 433  *
 434  * @param string $url
 435  * @param string|string[] $query String or associative array
 436  * @return string
 437  */
 438 function wfAppendQuery( $url, $query ) {
 439         if ( is_array( $query ) ) {
 440                 $query = wfArrayToCgi( $query );
 441         }
 442         if ( $query != '' ) {
 443                 // Remove the fragment, if there is one
 444                 $fragment = false;
 445                 $hashPos = strpos( $url, '#' );
 446                 if ( $hashPos !== false ) {
 447                         $fragment = substr( $url, $hashPos );
 448                         $url = substr( $url, 0, $hashPos );
 449                 }
 450
 451                 // Add parameter
 452                 if ( strpos( $url, '?' ) === false ) {
 453                         $url .= '?';
 454                 } else {
 455                         $url .= '&';
 456                 }
 457                 $url .= $query;
 458
 459                 // Put the fragment back
 460                 if ( $fragment !== false ) {
 461                         $url .= $fragment;
 462                 }
 463         }
 464         return $url;
 465 }
 466
 467 /**
 468  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 469  * is correct.
 470  *
 471  * The meaning of the PROTO_* constants is as follows:
 472  * PROTO_HTTP: Output a URL starting with http://
 473  * PROTO_HTTPS: Output a URL starting with https://
 474  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 475  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 476  *    on which protocol was used for the current incoming request
 477  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 478  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 479  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 480  *
 481  * @todo this won't work with current-path-relative URLs
 482  * like "subdir/foo.html", etc.
 483  *
 484  * @param string $url Either fully-qualified or a local path + query
 485  * @param string|int|null $defaultProto One of the PROTO_* constants. Determines the
 486  *    protocol to use if $url or $wgServer is protocol-relative
 487  * @return string|false Fully-qualified URL, current-path-relative URL or false if
 488  *    no valid URL can be constructed
 489  */
 490 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 491         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 492                 $wgHttpsPort;
 493         if ( $defaultProto === PROTO_CANONICAL ) {
 494                 $serverUrl = $wgCanonicalServer;
 495         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 496                 // Make $wgInternalServer fall back to $wgServer if not set
 497                 $serverUrl = $wgInternalServer;
 498         } else {
 499                 $serverUrl = $wgServer;
 500                 if ( $defaultProto === PROTO_CURRENT ) {
 501                         $defaultProto = $wgRequest->getProtocol() . '://';
 502                 }
 503         }
 504
 505         // Analyze $serverUrl to obtain its protocol
 506         $bits = wfParseUrl( $serverUrl );
 507         $serverHasProto = $bits && $bits['scheme'] != '';
 508
 509         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 510                 if ( $serverHasProto ) {
 511                         $defaultProto = $bits['scheme'] . '://';
 512                 } else {
 513                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 514                         // This really isn't supposed to happen. Fall back to HTTP in this
 515                         // ridiculous case.
 516                         $defaultProto = PROTO_HTTP;
 517                 }
 518         }
 519
 520         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 521
 522         if ( substr( $url, 0, 2 ) == '//' ) {
 523                 $url = $defaultProtoWithoutSlashes . $url;
 524         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 525                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 526                 // otherwise leave it alone.
 527                 if ( $serverHasProto ) {
 528                         $url = $serverUrl . $url;
 529                 } else {
 530                         // If an HTTPS URL is synthesized from a protocol-relative $wgServer, allow the
 531                         // user to override the port number (T67184)
 532                         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 533                                 if ( isset( $bits['port'] ) ) {
 534                                         throw new Exception( 'A protocol-relative $wgServer may not contain a port number' );
 535                                 }
 536                                 $url = $defaultProtoWithoutSlashes . $serverUrl . ':' . $wgHttpsPort . $url;
 537                         } else {
 538                                 $url = $defaultProtoWithoutSlashes . $serverUrl . $url;
 539                         }
 540                 }
 541         }
 542
 543         $bits = wfParseUrl( $url );
 544
 545         if ( $bits && isset( $bits['path'] ) ) {
 546                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 547                 return wfAssembleUrl( $bits );
 548         } elseif ( $bits ) {
 549                 # No path to expand
 550                 return $url;
 551         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 552                 # URL is a relative path
 553                 return wfRemoveDotSegments( $url );
 554         }
 555
 556         # Expanded URL is not valid.
 557         return false;
 558 }
 559
 560 /**
 561  * Get the wiki's "server", i.e. the protocol and host part of the URL, with a
 562  * protocol specified using a PROTO_* constant as in wfExpandUrl()
 563  *
 564  * @since 1.32
 565  * @param string|int|null $proto One of the PROTO_* constants.
 566  * @return string The URL
 567  */
 568 function wfGetServerUrl( $proto ) {
 569         $url = wfExpandUrl( '/', $proto );
 570         return substr( $url, 0, -1 );
 571 }
 572
 573 /**
 574  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 575  * if you need to edit part of a URL and put it back together.
 576  *
 577  * This is the basic structure used (brackets contain keys for $urlParts):
 578  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 579  *
 580  * @todo Need to integrate this into wfExpandUrl (see T34168)
 581  *
 582  * @since 1.19
 583  * @param array $urlParts URL parts, as output from wfParseUrl
 584  * @return string URL assembled from its component parts
 585  */
 586 function wfAssembleUrl( $urlParts ) {
 587         $result = '';
 588
 589         if ( isset( $urlParts['delimiter'] ) ) {
 590                 if ( isset( $urlParts['scheme'] ) ) {
 591                         $result .= $urlParts['scheme'];
 592                 }
 593
 594                 $result .= $urlParts['delimiter'];
 595         }
 596
 597         if ( isset( $urlParts['host'] ) ) {
 598                 if ( isset( $urlParts['user'] ) ) {
 599                         $result .= $urlParts['user'];
 600                         if ( isset( $urlParts['pass'] ) ) {
 601                                 $result .= ':' . $urlParts['pass'];
 602                         }
 603                         $result .= '@';
 604                 }
 605
 606                 $result .= $urlParts['host'];
 607
 608                 if ( isset( $urlParts['port'] ) ) {
 609                         $result .= ':' . $urlParts['port'];
 610                 }
 611         }
 612
 613         if ( isset( $urlParts['path'] ) ) {
 614                 $result .= $urlParts['path'];
 615         }
 616
 617         if ( isset( $urlParts['query'] ) ) {
 618                 $result .= '?' . $urlParts['query'];
 619         }
 620
 621         if ( isset( $urlParts['fragment'] ) ) {
 622                 $result .= '#' . $urlParts['fragment'];
 623         }
 624
 625         return $result;
 626 }
 627
 628 /**
 629  * Remove all dot-segments in the provided URL path.  For example,
 630  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 631  * RFC3986 section 5.2.4.
 632  *
 633  * @todo Need to integrate this into wfExpandUrl (see T34168)
 634  *
 635  * @since 1.19
 636  *
 637  * @param string $urlPath URL path, potentially containing dot-segments
 638  * @return string URL path with all dot-segments removed
 639  */
 640 function wfRemoveDotSegments( $urlPath ) {
 641         $output = '';
 642         $inputOffset = 0;
 643         $inputLength = strlen( $urlPath );
 644
 645         while ( $inputOffset < $inputLength ) {
 646                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 647                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 648                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 649                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 650                 $trimOutput = false;
 651
 652                 if ( $prefixLengthTwo == './' ) {
 653                         # Step A, remove leading "./"
 654                         $inputOffset += 2;
 655                 } elseif ( $prefixLengthThree == '../' ) {
 656                         # Step A, remove leading "../"
 657                         $inputOffset += 3;
 658                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 659                         # Step B, replace leading "/.$" with "/"
 660                         $inputOffset += 1;
 661                         $urlPath[$inputOffset] = '/';
 662                 } elseif ( $prefixLengthThree == '/./' ) {
 663                         # Step B, replace leading "/./" with "/"
 664                         $inputOffset += 2;
 665                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 666                         # Step C, replace leading "/..$" with "/" and
 667                         # remove last path component in output
 668                         $inputOffset += 2;
 669                         $urlPath[$inputOffset] = '/';
 670                         $trimOutput = true;
 671                 } elseif ( $prefixLengthFour == '/../' ) {
 672                         # Step C, replace leading "/../" with "/" and
 673                         # remove last path component in output
 674                         $inputOffset += 3;
 675                         $trimOutput = true;
 676                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 677                         # Step D, remove "^.$"
 678                         $inputOffset += 1;
 679                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 680                         # Step D, remove "^..$"
 681                         $inputOffset += 2;
 682                 } else {
 683                         # Step E, move leading path segment to output
 684                         if ( $prefixLengthOne == '/' ) {
 685                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 686                         } else {
 687                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 688                         }
 689                         if ( $slashPos === false ) {
 690                                 $output .= substr( $urlPath, $inputOffset );
 691                                 $inputOffset = $inputLength;
 692                         } else {
 693                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 694                                 $inputOffset += $slashPos - $inputOffset;
 695                         }
 696                 }
 697
 698                 if ( $trimOutput ) {
 699                         $slashPos = strrpos( $output, '/' );
 700                         if ( $slashPos === false ) {
 701                                 $output = '';
 702                         } else {
 703                                 $output = substr( $output, 0, $slashPos );
 704                         }
 705                 }
 706         }
 707
 708         return $output;
 709 }
 710
 711 /**
 712  * Returns a regular expression of url protocols
 713  *
 714  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 715  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 716  * @return string
 717  */
 718 function wfUrlProtocols( $includeProtocolRelative = true ) {
 719         global $wgUrlProtocols;
 720
 721         // Cache return values separately based on $includeProtocolRelative
 722         static $withProtRel = null, $withoutProtRel = null;
 723         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 724         if ( !is_null( $cachedValue ) ) {
 725                 return $cachedValue;
 726         }
 727
 728         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 729         // with LocalSettings files from 1.5
 730         if ( is_array( $wgUrlProtocols ) ) {
 731                 $protocols = [];
 732                 foreach ( $wgUrlProtocols as $protocol ) {
 733                         // Filter out '//' if !$includeProtocolRelative
 734                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 735                                 $protocols[] = preg_quote( $protocol, '/' );
 736                         }
 737                 }
 738
 739                 $retval = implode( '|', $protocols );
 740         } else {
 741                 // Ignore $includeProtocolRelative in this case
 742                 // This case exists for pre-1.6 compatibility, and we can safely assume
 743                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 744                 // URLs weren't supported until 1.18
 745                 $retval = $wgUrlProtocols;
 746         }
 747
 748         // Cache return value
 749         if ( $includeProtocolRelative ) {
 750                 $withProtRel = $retval;
 751         } else {
 752                 $withoutProtRel = $retval;
 753         }
 754         return $retval;
 755 }
 756
 757 /**
 758  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 759  * you need a regex that matches all URL protocols but does not match protocol-
 760  * relative URLs
 761  * @return string
 762  */
 763 function wfUrlProtocolsWithoutProtRel() {
 764         return wfUrlProtocols( false );
 765 }
 766
 767 /**
 768  * parse_url() work-alike, but non-broken.  Differences:
 769  *
 770  * 1) Does not raise warnings on bad URLs (just returns false).
 771  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 772  *    protocol-relative URLs) correctly.
 773  * 3) Adds a "delimiter" element to the array (see (2)).
 774  * 4) Verifies that the protocol is on the $wgUrlProtocols whitelist.
 775  * 5) Rejects some invalid URLs that parse_url doesn't, e.g. the empty string or URLs starting with
 776  *    a line feed character.
 777  *
 778  * @param string $url A URL to parse
 779  * @return string[]|bool Bits of the URL in an associative array, or false on failure.
 780  *   Possible fields:
 781  *   - scheme: URI scheme (protocol), e.g. 'http', 'mailto'. Lowercase, always present, but can
 782  *       be an empty string for protocol-relative URLs.
 783  *   - delimiter: either '://', ':' or '//'. Always present.
 784  *   - host: domain name / IP. Always present, but could be an empty string, e.g. for file: URLs.
 785  *   - user: user name, e.g. for HTTP Basic auth URLs such as http://user:pass@example.com/
 786  *       Missing when there is no username.
 787  *   - pass: password, same as above.
 788  *   - path: path including the leading /. Will be missing when empty (e.g. 'http://example.com')
 789  *   - query: query string (as a string; see wfCgiToArray() for parsing it), can be missing.
 790  *   - fragment: the part after #, can be missing.
 791  */
 792 function wfParseUrl( $url ) {
 793         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 794
 795         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 796         // bad that the easiest way to handle them is to just prepend 'http:' and
 797         // strip the protocol out later.
 798         $wasRelative = substr( $url, 0, 2 ) == '//';
 799         if ( $wasRelative ) {
 800                 $url = "http:$url";
 801         }
 802         Wikimedia\suppressWarnings();
 803         $bits = parse_url( $url );
 804         Wikimedia\restoreWarnings();
 805         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 806         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 807         if ( !$bits || !isset( $bits['scheme'] ) ) {
 808                 return false;
 809         }
 810
 811         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 812         $bits['scheme'] = strtolower( $bits['scheme'] );
 813
 814         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 815         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 816                 $bits['delimiter'] = '://';
 817         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 818                 $bits['delimiter'] = ':';
 819                 // parse_url detects for news: and mailto: the host part of an url as path
 820                 // We have to correct this wrong detection
 821                 if ( isset( $bits['path'] ) ) {
 822                         $bits['host'] = $bits['path'];
 823                         $bits['path'] = '';
 824                 }
 825         } else {
 826                 return false;
 827         }
 828
 829         /* Provide an empty host for eg. file:/// urls (see T30627) */
 830         if ( !isset( $bits['host'] ) ) {
 831                 $bits['host'] = '';
 832
 833                 // See T47069
 834                 if ( isset( $bits['path'] ) ) {
 835                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 836                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 837                                 $bits['path'] = '/' . $bits['path'];
 838                         }
 839                 } else {
 840                         $bits['path'] = '';
 841                 }
 842         }
 843
 844         // If the URL was protocol-relative, fix scheme and delimiter
 845         if ( $wasRelative ) {
 846                 $bits['scheme'] = '';
 847                 $bits['delimiter'] = '//';
 848         }
 849         return $bits;
 850 }
 851
 852 /**
 853  * Take a URL, make sure it's expanded to fully qualified, and replace any
 854  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 855  * for more compact display and legibility for local audiences.
 856  *
 857  * @todo handle punycode domains too
 858  *
 859  * @param string $url
 860  * @return string
 861  */
 862 function wfExpandIRI( $url ) {
 863         return preg_replace_callback(
 864                 '/((?:%[89A-F][0-9A-F])+)/i',
 865                 function ( array $matches ) {
 866                         return urldecode( $matches[1] );
 867                 },
 868                 wfExpandUrl( $url )
 869         );
 870 }
 871
 872 /**
 873  * Check whether a given URL has a domain that occurs in a given set of domains
 874  * @param string $url
 875  * @param array $domains Array of domains (strings)
 876  * @return bool True if the host part of $url ends in one of the strings in $domains
 877  */
 878 function wfMatchesDomainList( $url, $domains ) {
 879         $bits = wfParseUrl( $url );
 880         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 881                 $host = '.' . $bits['host'];
 882                 foreach ( (array)$domains as $domain ) {
 883                         $domain = '.' . $domain;
 884                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 885                                 return true;
 886                         }
 887                 }
 888         }
 889         return false;
 890 }
 891
 892 /**
 893  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 894  * In normal operation this is a NOP.
 895  *
 896  * Controlling globals:
 897  * $wgDebugLogFile - points to the log file
 898  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 899  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 900  *
 901  * @since 1.25 support for additional context data
 902  *
 903  * @param string $text
 904  * @param string|bool $dest Destination of the message:
 905  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 906  *     - 'private': excluded from HTML output
 907  *   For backward compatibility, it can also take a boolean:
 908  *     - true: same as 'all'
 909  *     - false: same as 'private'
 910  * @param array $context Additional logging context data
 911  */
 912 function wfDebug( $text, $dest = 'all', array $context = [] ) {
 913         global $wgDebugRawPage, $wgDebugLogPrefix;
 914         global $wgDebugTimestamps;
 915
 916         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 917                 return;
 918         }
 919
 920         $text = trim( $text );
 921
 922         if ( $wgDebugTimestamps ) {
 923                 $context['seconds_elapsed'] = sprintf(
 924                         '%6.4f',
 925                         microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT']
 926                 );
 927                 $context['memory_used'] = sprintf(
 928                         '%5.1fM',
 929                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
 930                 );
 931         }
 932
 933         if ( $wgDebugLogPrefix !== '' ) {
 934                 $context['prefix'] = $wgDebugLogPrefix;
 935         }
 936         $context['private'] = ( $dest === false || $dest === 'private' );
 937
 938         $logger = LoggerFactory::getInstance( 'wfDebug' );
 939         $logger->debug( $text, $context );
 940 }
 941
 942 /**
 943  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 944  * @return bool
 945  */
 946 function wfIsDebugRawPage() {
 947         static $cache;
 948         if ( $cache !== null ) {
 949                 return $cache;
 950         }
 951         // Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 952         // phpcs:ignore MediaWiki.Usage.SuperGlobalsUsage.SuperGlobals
 953         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 954                 || (
 955                         isset( $_SERVER['SCRIPT_NAME'] )
 956                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 957                 )
 958         ) {
 959                 $cache = true;
 960         } else {
 961                 $cache = false;
 962         }
 963         return $cache;
 964 }
 965
 966 /**
 967  * Send a line giving PHP memory usage.
 968  *
 969  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
 970  */
 971 function wfDebugMem( $exact = false ) {
 972         $mem = memory_get_usage();
 973         if ( !$exact ) {
 974                 $mem = floor( $mem / 1024 ) . ' KiB';
 975         } else {
 976                 $mem .= ' B';
 977         }
 978         wfDebug( "Memory usage: $mem\n" );
 979 }
 980
 981 /**
 982  * Send a line to a supplementary debug log file, if configured, or main debug
 983  * log if not.
 984  *
 985  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
 986  * a string filename or an associative array mapping 'destination' to the
 987  * desired filename. The associative array may also contain a 'sample' key
 988  * with an integer value, specifying a sampling factor. Sampled log events
 989  * will be emitted with a 1 in N random chance.
 990  *
 991  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
 992  * @since 1.25 support for additional context data
 993  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
 994  *
 995  * @param string $logGroup
 996  * @param string $text
 997  * @param string|bool $dest Destination of the message:
 998  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 999  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1000  *       discarded otherwise
1001  *   For backward compatibility, it can also take a boolean:
1002  *     - true: same as 'all'
1003  *     - false: same as 'private'
1004  * @param array $context Additional logging context data
1005  */
1006 function wfDebugLog(
1007         $logGroup, $text, $dest = 'all', array $context = []
1008 ) {
1009         $text = trim( $text );
1010
1011         $logger = LoggerFactory::getInstance( $logGroup );
1012         $context['private'] = ( $dest === false || $dest === 'private' );
1013         $logger->info( $text, $context );
1014 }
1015
1016 /**
1017  * Log for database errors
1018  *
1019  * @since 1.25 support for additional context data
1020  *
1021  * @param string $text Database error message.
1022  * @param array $context Additional logging context data
1023  */
1024 function wfLogDBError( $text, array $context = [] ) {
1025         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1026         $logger->error( trim( $text ), $context );
1027 }
1028
1029 /**
1030  * Throws a warning that $function is deprecated
1031  *
1032  * @param string $function Function that is deprecated.
1033  * @param string|bool $version Version of MediaWiki that the function
1034  *    was deprecated in (Added in 1.19).
1035  * @param string|bool $component Component to which the function belongs.
1036  *    If false, it is assumed the function is in MediaWiki core (Added in 1.19).
1037  * @param int $callerOffset How far up the call stack is the original
1038  *    caller. 2 = function that called the function that called
1039  *    wfDeprecated (Added in 1.20).
1040  */
1041 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1042         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1043 }
1044
1045 /**
1046  * Send a warning either to the debug log or in a PHP error depending on
1047  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1048  *
1049  * @param string $msg Message to send
1050  * @param int $callerOffset Number of items to go back in the backtrace to
1051  *        find the correct caller (1 = function calling wfWarn, ...)
1052  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1053  *        only used when $wgDevelopmentWarnings is true
1054  */
1055 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1056         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1057 }
1058
1059 /**
1060  * Send a warning as a PHP error and the debug log. This is intended for logging
1061  * warnings in production. For logging development warnings, use WfWarn instead.
1062  *
1063  * @param string $msg Message to send
1064  * @param int $callerOffset Number of items to go back in the backtrace to
1065  *        find the correct caller (1 = function calling wfLogWarning, ...)
1066  * @param int $level PHP error level; defaults to E_USER_WARNING
1067  */
1068 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1069         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1070 }
1071
1072 /**
1073  * @todo document
1074  * @todo Move logic to MediaWiki.php
1075  */
1076 function wfLogProfilingData() {
1077         global $wgDebugLogGroups, $wgDebugRawPage;
1078
1079         $context = RequestContext::getMain();
1080         $request = $context->getRequest();
1081
1082         $profiler = Profiler::instance();
1083         $profiler->setContext( $context );
1084         $profiler->logData();
1085
1086         // Send out any buffered statsd metrics as needed
1087         MediaWiki::emitBufferedStatsdData(
1088                 MediaWikiServices::getInstance()->getStatsdDataFactory(),
1089                 $context->getConfig()
1090         );
1091
1092         // Profiling must actually be enabled...
1093         if ( $profiler instanceof ProfilerStub ) {
1094                 return;
1095         }
1096
1097         if ( isset( $wgDebugLogGroups['profileoutput'] )
1098                 && $wgDebugLogGroups['profileoutput'] === false
1099         ) {
1100                 // Explicitly disabled
1101                 return;
1102         }
1103         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1104                 return;
1105         }
1106
1107         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1108         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1109                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1110         }
1111         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1112                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1113         }
1114         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1115                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1116         }
1117         if ( isset( $ctx['forwarded_for'] ) ||
1118                 isset( $ctx['client_ip'] ) ||
1119                 isset( $ctx['from'] ) ) {
1120                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1121         }
1122
1123         // Don't load $wgUser at this late stage just for statistics purposes
1124         // @todo FIXME: We can detect some anons even if it is not loaded.
1125         // See User::getId()
1126         $user = $context->getUser();
1127         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1128
1129         // Command line script uses a FauxRequest object which does not have
1130         // any knowledge about an URL and throw an exception instead.
1131         try {
1132                 $ctx['url'] = urldecode( $request->getRequestURL() );
1133         } catch ( Exception $ignored ) {
1134                 // no-op
1135         }
1136
1137         $ctx['output'] = $profiler->getOutput();
1138
1139         $log = LoggerFactory::getInstance( 'profileoutput' );
1140         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1141 }
1142
1143 /**
1144  * Increment a statistics counter
1145  *
1146  * @param string $key
1147  * @param int $count
1148  * @return void
1149  */
1150 function wfIncrStats( $key, $count = 1 ) {
1151         $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1152         $stats->updateCount( $key, $count );
1153 }
1154
1155 /**
1156  * Check whether the wiki is in read-only mode.
1157  *
1158  * @return bool
1159  */
1160 function wfReadOnly() {
1161         return MediaWikiServices::getInstance()->getReadOnlyMode()
1162                 ->isReadOnly();
1163 }
1164
1165 /**
1166  * Check if the site is in read-only mode and return the message if so
1167  *
1168  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1169  * for replica DB lag. This may result in DB connection being made.
1170  *
1171  * @return string|bool String when in read-only mode; false otherwise
1172  */
1173 function wfReadOnlyReason() {
1174         return MediaWikiServices::getInstance()->getReadOnlyMode()
1175                 ->getReason();
1176 }
1177
1178 /**
1179  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1180  *
1181  * @return string|bool String when in read-only mode; false otherwise
1182  * @since 1.27
1183  */
1184 function wfConfiguredReadOnlyReason() {
1185         return MediaWikiServices::getInstance()->getConfiguredReadOnlyMode()
1186                 ->getReason();
1187 }
1188
1189 /**
1190  * Return a Language object from $langcode
1191  *
1192  * @param Language|string|bool $langcode Either:
1193  *                  - a Language object
1194  *                  - code of the language to get the message for, if it is
1195  *                    a valid code create a language for that language, if
1196  *                    it is a string but not a valid code then make a basic
1197  *                    language object
1198  *                  - a boolean: if it's false then use the global object for
1199  *                    the current user's language (as a fallback for the old parameter
1200  *                    functionality), or if it is true then use global object
1201  *                    for the wiki's content language.
1202  * @return Language
1203  */
1204 function wfGetLangObj( $langcode = false ) {
1205         # Identify which language to get or create a language object for.
1206         # Using is_object here due to Stub objects.
1207         if ( is_object( $langcode ) ) {
1208                 # Great, we already have the object (hopefully)!
1209                 return $langcode;
1210         }
1211
1212         global $wgLanguageCode;
1213         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1214                 # $langcode is the language code of the wikis content language object.
1215                 # or it is a boolean and value is true
1216                 return MediaWikiServices::getInstance()->getContentLanguage();
1217         }
1218
1219         global $wgLang;
1220         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1221                 # $langcode is the language code of user language object.
1222                 # or it was a boolean and value is false
1223                 return $wgLang;
1224         }
1225
1226         $validCodes = array_keys( Language::fetchLanguageNames() );
1227         if ( in_array( $langcode, $validCodes ) ) {
1228                 # $langcode corresponds to a valid language.
1229                 return Language::factory( $langcode );
1230         }
1231
1232         # $langcode is a string, but not a valid language code; use content language.
1233         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1234         return MediaWikiServices::getInstance()->getContentLanguage();
1235 }
1236
1237 /**
1238  * This is the function for getting translated interface messages.
1239  *
1240  * @see Message class for documentation how to use them.
1241  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1242  *
1243  * This function replaces all old wfMsg* functions.
1244  *
1245  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1246  * @param string|string[] ...$params Normal message parameters
1247  * @return Message
1248  *
1249  * @since 1.17
1250  *
1251  * @see Message::__construct
1252  */
1253 function wfMessage( $key, ...$params ) {
1254         $message = new Message( $key );
1255
1256         // We call Message::params() to reduce code duplication
1257         if ( $params ) {
1258                 $message->params( ...$params );
1259         }
1260
1261         return $message;
1262 }
1263
1264 /**
1265  * This function accepts multiple message keys and returns a message instance
1266  * for the first message which is non-empty. If all messages are empty then an
1267  * instance of the first message key is returned.
1268  *
1269  * @param string ...$keys Message keys
1270  * @return Message
1271  *
1272  * @since 1.18
1273  *
1274  * @see Message::newFallbackSequence
1275  */
1276 function wfMessageFallback( ...$keys ) {
1277         return Message::newFallbackSequence( ...$keys );
1278 }
1279
1280 /**
1281  * Replace message parameter keys on the given formatted output.
1282  *
1283  * @param string $message
1284  * @param array $args
1285  * @return string
1286  * @private
1287  */
1288 function wfMsgReplaceArgs( $message, $args ) {
1289         # Fix windows line-endings
1290         # Some messages are split with explode("\n", $msg)
1291         $message = str_replace( "\r", '', $message );
1292
1293         // Replace arguments
1294         if ( is_array( $args ) && $args ) {
1295                 if ( is_array( $args[0] ) ) {
1296                         $args = array_values( $args[0] );
1297                 }
1298                 $replacementKeys = [];
1299                 foreach ( $args as $n => $param ) {
1300                         $replacementKeys['$' . ( $n + 1 )] = $param;
1301                 }
1302                 $message = strtr( $message, $replacementKeys );
1303         }
1304
1305         return $message;
1306 }
1307
1308 /**
1309  * Fetch server name for use in error reporting etc.
1310  * Use real server name if available, so we know which machine
1311  * in a server farm generated the current page.
1312  *
1313  * @return string
1314  */
1315 function wfHostname() {
1316         static $host;
1317         if ( is_null( $host ) ) {
1318                 # Hostname overriding
1319                 global $wgOverrideHostname;
1320                 if ( $wgOverrideHostname !== false ) {
1321                         # Set static and skip any detection
1322                         $host = $wgOverrideHostname;
1323                         return $host;
1324                 }
1325
1326                 if ( function_exists( 'posix_uname' ) ) {
1327                         // This function not present on Windows
1328                         $uname = posix_uname();
1329                 } else {
1330                         $uname = false;
1331                 }
1332                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1333                         $host = $uname['nodename'];
1334                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1335                         # Windows computer name
1336                         $host = getenv( 'COMPUTERNAME' );
1337                 } else {
1338                         # This may be a virtual server.
1339                         $host = $_SERVER['SERVER_NAME'];
1340                 }
1341         }
1342         return $host;
1343 }
1344
1345 /**
1346  * Returns a script tag that stores the amount of time it took MediaWiki to
1347  * handle the request in milliseconds as 'wgBackendResponseTime'.
1348  *
1349  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1350  * hostname of the server handling the request.
1351  *
1352  * @param string|null $nonce Value from OutputPage::getCSPNonce
1353  * @return string|WrappedString HTML
1354  */
1355 function wfReportTime( $nonce = null ) {
1356         global $wgShowHostnames;
1357
1358         $elapsed = ( microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT'] );
1359         // seconds to milliseconds
1360         $responseTime = round( $elapsed * 1000 );
1361         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1362         if ( $wgShowHostnames ) {
1363                 $reportVars['wgHostname'] = wfHostname();
1364         }
1365         return Skin::makeVariablesScript( $reportVars, $nonce );
1366 }
1367
1368 /**
1369  * Safety wrapper for debug_backtrace().
1370  *
1371  * Will return an empty array if debug_backtrace is disabled, otherwise
1372  * the output from debug_backtrace() (trimmed).
1373  *
1374  * @param int $limit This parameter can be used to limit the number of stack frames returned
1375  *
1376  * @return array Array of backtrace information
1377  */
1378 function wfDebugBacktrace( $limit = 0 ) {
1379         static $disabled = null;
1380
1381         if ( is_null( $disabled ) ) {
1382                 $disabled = !function_exists( 'debug_backtrace' );
1383                 if ( $disabled ) {
1384                         wfDebug( "debug_backtrace() is disabled\n" );
1385                 }
1386         }
1387         if ( $disabled ) {
1388                 return [];
1389         }
1390
1391         if ( $limit ) {
1392                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1393         } else {
1394                 return array_slice( debug_backtrace(), 1 );
1395         }
1396 }
1397
1398 /**
1399  * Get a debug backtrace as a string
1400  *
1401  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1402  *   Defaults to $wgCommandLineMode if unset.
1403  * @return string
1404  * @since 1.25 Supports $raw parameter.
1405  */
1406 function wfBacktrace( $raw = null ) {
1407         global $wgCommandLineMode;
1408
1409         if ( $raw === null ) {
1410                 $raw = $wgCommandLineMode;
1411         }
1412
1413         if ( $raw ) {
1414                 $frameFormat = "%s line %s calls %s()\n";
1415                 $traceFormat = "%s";
1416         } else {
1417                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1418                 $traceFormat = "<ul>\n%s</ul>\n";
1419         }
1420
1421         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1422                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1423                 $line = $frame['line'] ?? '-';
1424                 $call = $frame['function'];
1425                 if ( !empty( $frame['class'] ) ) {
1426                         $call = $frame['class'] . $frame['type'] . $call;
1427                 }
1428                 return sprintf( $frameFormat, $file, $line, $call );
1429         }, wfDebugBacktrace() );
1430
1431         return sprintf( $traceFormat, implode( '', $frames ) );
1432 }
1433
1434 /**
1435  * Get the name of the function which called this function
1436  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1437  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1438  * wfGetCaller( 3 ) is the parent of that.
1439  *
1440  * @param int $level
1441  * @return string
1442  */
1443 function wfGetCaller( $level = 2 ) {
1444         $backtrace = wfDebugBacktrace( $level + 1 );
1445         if ( isset( $backtrace[$level] ) ) {
1446                 return wfFormatStackFrame( $backtrace[$level] );
1447         } else {
1448                 return 'unknown';
1449         }
1450 }
1451
1452 /**
1453  * Return a string consisting of callers in the stack. Useful sometimes
1454  * for profiling specific points.
1455  *
1456  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1457  * @return string
1458  */
1459 function wfGetAllCallers( $limit = 3 ) {
1460         $trace = array_reverse( wfDebugBacktrace() );
1461         if ( !$limit || $limit > count( $trace ) - 1 ) {
1462                 $limit = count( $trace ) - 1;
1463         }
1464         $trace = array_slice( $trace, -$limit - 1, $limit );
1465         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1466 }
1467
1468 /**
1469  * Return a string representation of frame
1470  *
1471  * @param array $frame
1472  * @return string
1473  */
1474 function wfFormatStackFrame( $frame ) {
1475         if ( !isset( $frame['function'] ) ) {
1476                 return 'NO_FUNCTION_GIVEN';
1477         }
1478         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1479                 $frame['class'] . $frame['type'] . $frame['function'] :
1480                 $frame['function'];
1481 }
1482
1483 /* Some generic result counters, pulled out of SearchEngine */
1484
1485 /**
1486  * @todo document
1487  *
1488  * @param int $offset
1489  * @param int $limit
1490  * @return string
1491  */
1492 function wfShowingResults( $offset, $limit ) {
1493         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1494 }
1495
1496 /**
1497  * Whether the client accept gzip encoding
1498  *
1499  * Uses the Accept-Encoding header to check if the client supports gzip encoding.
1500  * Use this when considering to send a gzip-encoded response to the client.
1501  *
1502  * @param bool $force Forces another check even if we already have a cached result.
1503  * @return bool
1504  */
1505 function wfClientAcceptsGzip( $force = false ) {
1506         static $result = null;
1507         if ( $result === null || $force ) {
1508                 $result = false;
1509                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1510                         # @todo FIXME: We may want to blacklist some broken browsers
1511                         $m = [];
1512                         if ( preg_match(
1513                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1514                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1515                                         $m
1516                                 )
1517                         ) {
1518                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1519                                         $result = false;
1520                                         return $result;
1521                                 }
1522                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1523                                 $result = true;
1524                         }
1525                 }
1526         }
1527         return $result;
1528 }
1529
1530 /**
1531  * Escapes the given text so that it may be output using addWikiText()
1532  * without any linking, formatting, etc. making its way through. This
1533  * is achieved by substituting certain characters with HTML entities.
1534  * As required by the callers, "<nowiki>" is not used.
1535  *
1536  * @param string $text Text to be escaped
1537  * @param-taint $text escapes_html
1538  * @return string
1539  */
1540 function wfEscapeWikiText( $text ) {
1541         global $wgEnableMagicLinks;
1542         static $repl = null, $repl2 = null;
1543         if ( $repl === null || defined( 'MW_PARSER_TEST' ) || defined( 'MW_PHPUNIT_TEST' ) ) {
1544                 // Tests depend upon being able to change $wgEnableMagicLinks, so don't cache
1545                 // in those situations
1546                 $repl = [
1547                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1548                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1549                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1550                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1551                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1552                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1553                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1554                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1555                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1556                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1557                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1558                         '__' => '_&#95;', '://' => '&#58;//',
1559                 ];
1560
1561                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1562                 // We have to catch everything "\s" matches in PCRE
1563                 foreach ( $magicLinks as $magic ) {
1564                         $repl["$magic "] = "$magic&#32;";
1565                         $repl["$magic\t"] = "$magic&#9;";
1566                         $repl["$magic\r"] = "$magic&#13;";
1567                         $repl["$magic\n"] = "$magic&#10;";
1568                         $repl["$magic\f"] = "$magic&#12;";
1569                 }
1570
1571                 // And handle protocols that don't use "://"
1572                 global $wgUrlProtocols;
1573                 $repl2 = [];
1574                 foreach ( $wgUrlProtocols as $prot ) {
1575                         if ( substr( $prot, -1 ) === ':' ) {
1576                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1577                         }
1578                 }
1579                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1580         }
1581         $text = substr( strtr( "\n$text", $repl ), 1 );
1582         $text = preg_replace( $repl2, '$1&#58;', $text );
1583         return $text;
1584 }
1585
1586 /**
1587  * Sets dest to source and returns the original value of dest
1588  * If source is NULL, it just returns the value, it doesn't set the variable
1589  * If force is true, it will set the value even if source is NULL
1590  *
1591  * @param mixed &$dest
1592  * @param mixed $source
1593  * @param bool $force
1594  * @return mixed
1595  */
1596 function wfSetVar( &$dest, $source, $force = false ) {
1597         $temp = $dest;
1598         if ( !is_null( $source ) || $force ) {
1599                 $dest = $source;
1600         }
1601         return $temp;
1602 }
1603
1604 /**
1605  * As for wfSetVar except setting a bit
1606  *
1607  * @param int &$dest
1608  * @param int $bit
1609  * @param bool $state
1610  *
1611  * @return bool
1612  */
1613 function wfSetBit( &$dest, $bit, $state = true ) {
1614         $temp = (bool)( $dest & $bit );
1615         if ( !is_null( $state ) ) {
1616                 if ( $state ) {
1617                         $dest |= $bit;
1618                 } else {
1619                         $dest &= ~$bit;
1620                 }
1621         }
1622         return $temp;
1623 }
1624
1625 /**
1626  * A wrapper around the PHP function var_export().
1627  * Either print it or add it to the regular output ($wgOut).
1628  *
1629  * @param mixed $var A PHP variable to dump.
1630  */
1631 function wfVarDump( $var ) {
1632         global $wgOut;
1633         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1634         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1635                 print $s;
1636         } else {
1637                 $wgOut->addHTML( $s );
1638         }
1639 }
1640
1641 /**
1642  * Provide a simple HTTP error.
1643  *
1644  * @param int|string $code
1645  * @param string $label
1646  * @param string $desc
1647  */
1648 function wfHttpError( $code, $label, $desc ) {
1649         global $wgOut;
1650         HttpStatus::header( $code );
1651         if ( $wgOut ) {
1652                 $wgOut->disable();
1653                 $wgOut->sendCacheControl();
1654         }
1655
1656         MediaWiki\HeaderCallback::warnIfHeadersSent();
1657         header( 'Content-type: text/html; charset=utf-8' );
1658         print '<!DOCTYPE html>' .
1659                 '<html><head><title>' .
1660                 htmlspecialchars( $label ) .
1661                 '</title></head><body><h1>' .
1662                 htmlspecialchars( $label ) .
1663                 '</h1><p>' .
1664                 nl2br( htmlspecialchars( $desc ) ) .
1665                 "</p></body></html>\n";
1666 }
1667
1668 /**
1669  * Clear away any user-level output buffers, discarding contents.
1670  *
1671  * Suitable for 'starting afresh', for instance when streaming
1672  * relatively large amounts of data without buffering, or wanting to
1673  * output image files without ob_gzhandler's compression.
1674  *
1675  * The optional $resetGzipEncoding parameter controls suppression of
1676  * the Content-Encoding header sent by ob_gzhandler; by default it
1677  * is left. See comments for wfClearOutputBuffers() for why it would
1678  * be used.
1679  *
1680  * Note that some PHP configuration options may add output buffer
1681  * layers which cannot be removed; these are left in place.
1682  *
1683  * @param bool $resetGzipEncoding
1684  */
1685 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1686         if ( $resetGzipEncoding ) {
1687                 // Suppress Content-Encoding and Content-Length
1688                 // headers from OutputHandler::handle.
1689                 global $wgDisableOutputCompression;
1690                 $wgDisableOutputCompression = true;
1691         }
1692         while ( $status = ob_get_status() ) {
1693                 if ( isset( $status['flags'] ) ) {
1694                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1695                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1696                 } elseif ( isset( $status['del'] ) ) {
1697                         $deleteable = $status['del'];
1698                 } else {
1699                         // Guess that any PHP-internal setting can't be removed.
1700                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1701                 }
1702                 if ( !$deleteable ) {
1703                         // Give up, and hope the result doesn't break
1704                         // output behavior.
1705                         break;
1706                 }
1707                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1708                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1709                         break;
1710                 }
1711                 if ( !ob_end_clean() ) {
1712                         // Could not remove output buffer handler; abort now
1713                         // to avoid getting in some kind of infinite loop.
1714                         break;
1715                 }
1716                 if ( $resetGzipEncoding && $status['name'] == 'ob_gzhandler' ) {
1717                         // Reset the 'Content-Encoding' field set by this handler
1718                         // so we can start fresh.
1719                         header_remove( 'Content-Encoding' );
1720                         break;
1721                 }
1722         }
1723 }
1724
1725 /**
1726  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1727  *
1728  * Clear away output buffers, but keep the Content-Encoding header
1729  * produced by ob_gzhandler, if any.
1730  *
1731  * This should be used for HTTP 304 responses, where you need to
1732  * preserve the Content-Encoding header of the real result, but
1733  * also need to suppress the output of ob_gzhandler to keep to spec
1734  * and avoid breaking Firefox in rare cases where the headers and
1735  * body are broken over two packets.
1736  */
1737 function wfClearOutputBuffers() {
1738         wfResetOutputBuffers( false );
1739 }
1740
1741 /**
1742  * Converts an Accept-* header into an array mapping string values to quality
1743  * factors
1744  *
1745  * @param string $accept
1746  * @param string $def Default
1747  * @return float[] Associative array of string => float pairs
1748  */
1749 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1750         # No arg means accept anything (per HTTP spec)
1751         if ( !$accept ) {
1752                 return [ $def => 1.0 ];
1753         }
1754
1755         $prefs = [];
1756
1757         $parts = explode( ',', $accept );
1758
1759         foreach ( $parts as $part ) {
1760                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1761                 $values = explode( ';', trim( $part ) );
1762                 $match = [];
1763                 if ( count( $values ) == 1 ) {
1764                         $prefs[$values[0]] = 1.0;
1765                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1766                         $prefs[$values[0]] = floatval( $match[1] );
1767                 }
1768         }
1769
1770         return $prefs;
1771 }
1772
1773 /**
1774  * Checks if a given MIME type matches any of the keys in the given
1775  * array. Basic wildcards are accepted in the array keys.
1776  *
1777  * Returns the matching MIME type (or wildcard) if a match, otherwise
1778  * NULL if no match.
1779  *
1780  * @param string $type
1781  * @param array $avail
1782  * @return string
1783  * @private
1784  */
1785 function mimeTypeMatch( $type, $avail ) {
1786         if ( array_key_exists( $type, $avail ) ) {
1787                 return $type;
1788         } else {
1789                 $mainType = explode( '/', $type )[0];
1790                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1791                         return "$mainType/*";
1792                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1793                         return '*/*';
1794                 } else {
1795                         return null;
1796                 }
1797         }
1798 }
1799
1800 /**
1801  * Returns the 'best' match between a client's requested internet media types
1802  * and the server's list of available types. Each list should be an associative
1803  * array of type to preference (preference is a float between 0.0 and 1.0).
1804  * Wildcards in the types are acceptable.
1805  *
1806  * @param array $cprefs Client's acceptable type list
1807  * @param array $sprefs Server's offered types
1808  * @return string
1809  *
1810  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1811  * XXX: generalize to negotiate other stuff
1812  */
1813 function wfNegotiateType( $cprefs, $sprefs ) {
1814         $combine = [];
1815
1816         foreach ( array_keys( $sprefs ) as $type ) {
1817                 $subType = explode( '/', $type )[1];
1818                 if ( $subType != '*' ) {
1819                         $ckey = mimeTypeMatch( $type, $cprefs );
1820                         if ( $ckey ) {
1821                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1822                         }
1823                 }
1824         }
1825
1826         foreach ( array_keys( $cprefs ) as $type ) {
1827                 $subType = explode( '/', $type )[1];
1828                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1829                         $skey = mimeTypeMatch( $type, $sprefs );
1830                         if ( $skey ) {
1831                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1832                         }
1833                 }
1834         }
1835
1836         $bestq = 0;
1837         $besttype = null;
1838
1839         foreach ( array_keys( $combine ) as $type ) {
1840                 if ( $combine[$type] > $bestq ) {
1841                         $besttype = $type;
1842                         $bestq = $combine[$type];
1843                 }
1844         }
1845
1846         return $besttype;
1847 }
1848
1849 /**
1850  * Reference-counted warning suppression
1851  *
1852  * @deprecated since 1.26, use Wikimedia\suppressWarnings() directly
1853  * @param bool $end
1854  */
1855 function wfSuppressWarnings( $end = false ) {
1856         Wikimedia\suppressWarnings( $end );
1857 }
1858
1859 /**
1860  * @deprecated since 1.26, use Wikimedia\restoreWarnings() directly
1861  * Restore error level to previous value
1862  */
1863 function wfRestoreWarnings() {
1864         Wikimedia\restoreWarnings();
1865 }
1866
1867 /**
1868  * Get a timestamp string in one of various formats
1869  *
1870  * @param mixed $outputtype A timestamp in one of the supported formats, the
1871  *   function will autodetect which format is supplied and act accordingly.
1872  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
1873  * @return string|bool String / false The same date in the format specified in $outputtype or false
1874  */
1875 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
1876         $ret = MWTimestamp::convert( $outputtype, $ts );
1877         if ( $ret === false ) {
1878                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
1879         }
1880         return $ret;
1881 }
1882
1883 /**
1884  * Return a formatted timestamp, or null if input is null.
1885  * For dealing with nullable timestamp columns in the database.
1886  *
1887  * @param int $outputtype
1888  * @param string|null $ts
1889  * @return string
1890  */
1891 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
1892         if ( is_null( $ts ) ) {
1893                 return null;
1894         } else {
1895                 return wfTimestamp( $outputtype, $ts );
1896         }
1897 }
1898
1899 /**
1900  * Convenience function; returns MediaWiki timestamp for the present time.
1901  *
1902  * @return string
1903  */
1904 function wfTimestampNow() {
1905         # return NOW
1906         return MWTimestamp::now( TS_MW );
1907 }
1908
1909 /**
1910  * Check if the operating system is Windows
1911  *
1912  * @return bool True if it's Windows, false otherwise.
1913  */
1914 function wfIsWindows() {
1915         static $isWindows = null;
1916         if ( $isWindows === null ) {
1917                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
1918         }
1919         return $isWindows;
1920 }
1921
1922 /**
1923  * Check if we are running under HHVM
1924  *
1925  * @return bool
1926  */
1927 function wfIsHHVM() {
1928         return defined( 'HHVM_VERSION' );
1929 }
1930
1931 /**
1932  * Check if we are running from the commandline
1933  *
1934  * @since 1.31
1935  * @return bool
1936  */
1937 function wfIsCLI() {
1938         return PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg';
1939 }
1940
1941 /**
1942  * Tries to get the system directory for temporary files. First
1943  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
1944  * environment variables are then checked in sequence, then
1945  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
1946  *
1947  * NOTE: When possible, use instead the tmpfile() function to create
1948  * temporary files to avoid race conditions on file creation, etc.
1949  *
1950  * @return string
1951  */
1952 function wfTempDir() {
1953         global $wgTmpDirectory;
1954
1955         if ( $wgTmpDirectory !== false ) {
1956                 return $wgTmpDirectory;
1957         }
1958
1959         return TempFSFile::getUsableTempDirectory();
1960 }
1961
1962 /**
1963  * Make directory, and make all parent directories if they don't exist
1964  *
1965  * @param string $dir Full path to directory to create
1966  * @param int|null $mode Chmod value to use, default is $wgDirectoryMode
1967  * @param string|null $caller Optional caller param for debugging.
1968  * @throws MWException
1969  * @return bool
1970  */
1971 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
1972         global $wgDirectoryMode;
1973
1974         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
1975                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
1976         }
1977
1978         if ( !is_null( $caller ) ) {
1979                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
1980         }
1981
1982         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
1983                 return true;
1984         }
1985
1986         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
1987
1988         if ( is_null( $mode ) ) {
1989                 $mode = $wgDirectoryMode;
1990         }
1991
1992         // Turn off the normal warning, we're doing our own below
1993         Wikimedia\suppressWarnings();
1994         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
1995         Wikimedia\restoreWarnings();
1996
1997         if ( !$ok ) {
1998                 // directory may have been created on another request since we last checked
1999                 if ( is_dir( $dir ) ) {
2000                         return true;
2001                 }
2002
2003                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2004                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2005         }
2006         return $ok;
2007 }
2008
2009 /**
2010  * Remove a directory and all its content.
2011  * Does not hide error.
2012  * @param string $dir
2013  */
2014 function wfRecursiveRemoveDir( $dir ) {
2015         wfDebug( __FUNCTION__ . "( $dir )\n" );
2016         // taken from https://www.php.net/manual/en/function.rmdir.php#98622
2017         if ( is_dir( $dir ) ) {
2018                 $objects = scandir( $dir );
2019                 foreach ( $objects as $object ) {
2020                         if ( $object != "." && $object != ".." ) {
2021                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2022                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2023                                 } else {
2024                                         unlink( $dir . '/' . $object );
2025                                 }
2026                         }
2027                 }
2028                 reset( $objects );
2029                 rmdir( $dir );
2030         }
2031 }
2032
2033 /**
2034  * @param int $nr The number to format
2035  * @param int $acc The number of digits after the decimal point, default 2
2036  * @param bool $round Whether or not to round the value, default true
2037  * @return string
2038  */
2039 function wfPercent( $nr, $acc = 2, $round = true ) {
2040         $ret = sprintf( "%.${acc}f", $nr );
2041         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2042 }
2043
2044 /**
2045  * Safety wrapper around ini_get() for boolean settings.
2046  * The values returned from ini_get() are pre-normalized for settings
2047  * set via php.ini or php_flag/php_admin_flag... but *not*
2048  * for those set via php_value/php_admin_value.
2049  *
2050  * It's fairly common for people to use php_value instead of php_flag,
2051  * which can leave you with an 'off' setting giving a false positive
2052  * for code that just takes the ini_get() return value as a boolean.
2053  *
2054  * To make things extra interesting, setting via php_value accepts
2055  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2056  * Unrecognized values go false... again opposite PHP's own coercion
2057  * from string to bool.
2058  *
2059  * Luckily, 'properly' set settings will always come back as '0' or '1',
2060  * so we only have to worry about them and the 'improper' settings.
2061  *
2062  * I frickin' hate PHP... :P
2063  *
2064  * @param string $setting
2065  * @return bool
2066  */
2067 function wfIniGetBool( $setting ) {
2068         return wfStringToBool( ini_get( $setting ) );
2069 }
2070
2071 /**
2072  * Convert string value to boolean, when the following are interpreted as true:
2073  * - on
2074  * - true
2075  * - yes
2076  * - Any number, except 0
2077  * All other strings are interpreted as false.
2078  *
2079  * @param string $val
2080  * @return bool
2081  * @since 1.31
2082  */
2083 function wfStringToBool( $val ) {
2084         $val = strtolower( $val );
2085         // 'on' and 'true' can't have whitespace around them, but '1' can.
2086         return $val == 'on'
2087                 || $val == 'true'
2088                 || $val == 'yes'
2089                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2090 }
2091
2092 /**
2093  * Version of escapeshellarg() that works better on Windows.
2094  *
2095  * Originally, this fixed the incorrect use of single quotes on Windows
2096  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2097  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2098  *
2099  * @param string|string[] ...$args strings to escape and glue together,
2100  *  or a single array of strings parameter
2101  * @return string
2102  * @deprecated since 1.30 use MediaWiki\Shell\Shell::escape()
2103  */
2104 function wfEscapeShellArg( ...$args ) {
2105         return Shell::escape( ...$args );
2106 }
2107
2108 /**
2109  * Execute a shell command, with time and memory limits mirrored from the PHP
2110  * configuration if supported.
2111  *
2112  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2113  *   or an array of unescaped arguments, in which case each value will be escaped
2114  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2115  * @param null|mixed &$retval Optional, will receive the program's exit code.
2116  *   (non-zero is usually failure). If there is an error from
2117  *   read, select, or proc_open(), this will be set to -1.
2118  * @param array $environ Optional environment variables which should be
2119  *   added to the executed command environment.
2120  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2121  *   this overwrites the global wgMaxShell* limits.
2122  * @param array $options Array of options:
2123  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2124  *     including errors from limit.sh
2125  *   - profileMethod: By default this function will profile based on the calling
2126  *     method. Set this to a string for an alternative method to profile from
2127  *
2128  * @return string Collected stdout as a string
2129  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2130  */
2131 function wfShellExec( $cmd, &$retval = null, $environ = [],
2132         $limits = [], $options = []
2133 ) {
2134         if ( Shell::isDisabled() ) {
2135                 $retval = 1;
2136                 // Backwards compatibility be upon us...
2137                 return 'Unable to run external programs, proc_open() is disabled.';
2138         }
2139
2140         if ( is_array( $cmd ) ) {
2141                 $cmd = Shell::escape( $cmd );
2142         }
2143
2144         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2145         $profileMethod = $options['profileMethod'] ?? wfGetCaller();
2146
2147         try {
2148                 $result = Shell::command( [] )
2149                         ->unsafeParams( (array)$cmd )
2150                         ->environment( $environ )
2151                         ->limits( $limits )
2152                         ->includeStderr( $includeStderr )
2153                         ->profileMethod( $profileMethod )
2154                         // For b/c
2155                         ->restrict( Shell::RESTRICT_NONE )
2156                         ->execute();
2157         } catch ( ProcOpenError $ex ) {
2158                 $retval = -1;
2159                 return '';
2160         }
2161
2162         $retval = $result->getExitCode();
2163
2164         return $result->getStdout();
2165 }
2166
2167 /**
2168  * Execute a shell command, returning both stdout and stderr. Convenience
2169  * function, as all the arguments to wfShellExec can become unwieldy.
2170  *
2171  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2172  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2173  *   or an array of unescaped arguments, in which case each value will be escaped
2174  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2175  * @param null|mixed &$retval Optional, will receive the program's exit code.
2176  *   (non-zero is usually failure)
2177  * @param array $environ Optional environment variables which should be
2178  *   added to the executed command environment.
2179  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2180  *   this overwrites the global wgMaxShell* limits.
2181  * @return string Collected stdout and stderr as a string
2182  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2183  */
2184 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2185         return wfShellExec( $cmd, $retval, $environ, $limits,
2186                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2187 }
2188
2189 /**
2190  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2191  * Note that $parameters should be a flat array and an option with an argument
2192  * should consist of two consecutive items in the array (do not use "--option value").
2193  *
2194  * @deprecated since 1.31, use Shell::makeScriptCommand()
2195  *
2196  * @param string $script MediaWiki cli script path
2197  * @param array $parameters Arguments and options to the script
2198  * @param array $options Associative array of options:
2199  *     'php': The path to the php executable
2200  *     'wrapper': Path to a PHP wrapper to handle the maintenance script
2201  * @return string
2202  */
2203 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2204         global $wgPhpCli;
2205         // Give site config file a chance to run the script in a wrapper.
2206         // The caller may likely want to call wfBasename() on $script.
2207         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2208         $cmd = [ $options['php'] ?? $wgPhpCli ];
2209         if ( isset( $options['wrapper'] ) ) {
2210                 $cmd[] = $options['wrapper'];
2211         }
2212         $cmd[] = $script;
2213         // Escape each parameter for shell
2214         return Shell::escape( array_merge( $cmd, $parameters ) );
2215 }
2216
2217 /**
2218  * wfMerge attempts to merge differences between three texts.
2219  * Returns true for a clean merge and false for failure or a conflict.
2220  *
2221  * @param string $old
2222  * @param string $mine
2223  * @param string $yours
2224  * @param string &$result
2225  * @param string|null &$mergeAttemptResult
2226  * @return bool
2227  */
2228 function wfMerge( $old, $mine, $yours, &$result, &$mergeAttemptResult = null ) {
2229         global $wgDiff3;
2230
2231         # This check may also protect against code injection in
2232         # case of broken installations.
2233         Wikimedia\suppressWarnings();
2234         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2235         Wikimedia\restoreWarnings();
2236
2237         if ( !$haveDiff3 ) {
2238                 wfDebug( "diff3 not found\n" );
2239                 return false;
2240         }
2241
2242         # Make temporary files
2243         $td = wfTempDir();
2244         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2245         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2246         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2247
2248         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2249         #       a newline character. To avoid this, we normalize the trailing whitespace before
2250         #       creating the diff.
2251
2252         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2253         fclose( $oldtextFile );
2254         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2255         fclose( $mytextFile );
2256         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2257         fclose( $yourtextFile );
2258
2259         # Check for a conflict
2260         $cmd = Shell::escape( $wgDiff3, '-a', '--overlap-only', $mytextName,
2261                 $oldtextName, $yourtextName );
2262         $handle = popen( $cmd, 'r' );
2263
2264         $mergeAttemptResult = '';
2265         do {
2266                 $data = fread( $handle, 8192 );
2267                 if ( strlen( $data ) == 0 ) {
2268                         break;
2269                 }
2270                 $mergeAttemptResult .= $data;
2271         } while ( true );
2272         pclose( $handle );
2273
2274         $conflict = $mergeAttemptResult !== '';
2275
2276         # Merge differences
2277         $cmd = Shell::escape( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2278                 $oldtextName, $yourtextName );
2279         $handle = popen( $cmd, 'r' );
2280         $result = '';
2281         do {
2282                 $data = fread( $handle, 8192 );
2283                 if ( strlen( $data ) == 0 ) {
2284                         break;
2285                 }
2286                 $result .= $data;
2287         } while ( true );
2288         pclose( $handle );
2289         unlink( $mytextName );
2290         unlink( $oldtextName );
2291         unlink( $yourtextName );
2292
2293         if ( $result === '' && $old !== '' && !$conflict ) {
2294                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2295                 $conflict = true;
2296         }
2297         return !$conflict;
2298 }
2299
2300 /**
2301  * Returns unified plain-text diff of two texts.
2302  * "Useful" for machine processing of diffs.
2303  *
2304  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2305  *
2306  * @param string $before The text before the changes.
2307  * @param string $after The text after the changes.
2308  * @param string $params Command-line options for the diff command.
2309  * @return string Unified diff of $before and $after
2310  */
2311 function wfDiff( $before, $after, $params = '-u' ) {
2312         if ( $before == $after ) {
2313                 return '';
2314         }
2315
2316         global $wgDiff;
2317         Wikimedia\suppressWarnings();
2318         $haveDiff = $wgDiff && file_exists( $wgDiff );
2319         Wikimedia\restoreWarnings();
2320
2321         # This check may also protect against code injection in
2322         # case of broken installations.
2323         if ( !$haveDiff ) {
2324                 wfDebug( "diff executable not found\n" );
2325                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2326                 $format = new UnifiedDiffFormatter();
2327                 return $format->format( $diffs );
2328         }
2329
2330         # Make temporary files
2331         $td = wfTempDir();
2332         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2333         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2334
2335         fwrite( $oldtextFile, $before );
2336         fclose( $oldtextFile );
2337         fwrite( $newtextFile, $after );
2338         fclose( $newtextFile );
2339
2340         // Get the diff of the two files
2341         $cmd = "$wgDiff " . $params . ' ' . Shell::escape( $oldtextName, $newtextName );
2342
2343         $h = popen( $cmd, 'r' );
2344         if ( !$h ) {
2345                 unlink( $oldtextName );
2346                 unlink( $newtextName );
2347                 throw new Exception( __METHOD__ . '(): popen() failed' );
2348         }
2349
2350         $diff = '';
2351
2352         do {
2353                 $data = fread( $h, 8192 );
2354                 if ( strlen( $data ) == 0 ) {
2355                         break;
2356                 }
2357                 $diff .= $data;
2358         } while ( true );
2359
2360         // Clean up
2361         pclose( $h );
2362         unlink( $oldtextName );
2363         unlink( $newtextName );
2364
2365         // Kill the --- and +++ lines. They're not useful.
2366         $diff_lines = explode( "\n", $diff );
2367         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2368                 unset( $diff_lines[0] );
2369         }
2370         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2371                 unset( $diff_lines[1] );
2372         }
2373
2374         $diff = implode( "\n", $diff_lines );
2375
2376         return $diff;
2377 }
2378
2379 /**
2380  * Return the final portion of a pathname.
2381  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2382  * https://bugs.php.net/bug.php?id=33898
2383  *
2384  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2385  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2386  *
2387  * @param string $path
2388  * @param string $suffix String to remove if present
2389  * @return string
2390  */
2391 function wfBaseName( $path, $suffix = '' ) {
2392         if ( $suffix == '' ) {
2393                 $encSuffix = '';
2394         } else {
2395                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2396         }
2397
2398         $matches = [];
2399         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2400                 return $matches[1];
2401         } else {
2402                 return '';
2403         }
2404 }
2405
2406 /**
2407  * Generate a relative path name to the given file.
2408  * May explode on non-matching case-insensitive paths,
2409  * funky symlinks, etc.
2410  *
2411  * @param string $path Absolute destination path including target filename
2412  * @param string $from Absolute source path, directory only
2413  * @return string
2414  */
2415 function wfRelativePath( $path, $from ) {
2416         // Normalize mixed input on Windows...
2417         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2418         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2419
2420         // Trim trailing slashes -- fix for drive root
2421         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2422         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2423
2424         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2425         $against = explode( DIRECTORY_SEPARATOR, $from );
2426
2427         if ( $pieces[0] !== $against[0] ) {
2428                 // Non-matching Windows drive letters?
2429                 // Return a full path.
2430                 return $path;
2431         }
2432
2433         // Trim off common prefix
2434         while ( count( $pieces ) && count( $against )
2435                 && $pieces[0] == $against[0] ) {
2436                 array_shift( $pieces );
2437                 array_shift( $against );
2438         }
2439
2440         // relative dots to bump us to the parent
2441         while ( count( $against ) ) {
2442                 array_unshift( $pieces, '..' );
2443                 array_shift( $against );
2444         }
2445
2446         array_push( $pieces, wfBaseName( $path ) );
2447
2448         return implode( DIRECTORY_SEPARATOR, $pieces );
2449 }
2450
2451 /**
2452  * Reset the session id
2453  *
2454  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2455  * @since 1.22
2456  */
2457 function wfResetSessionID() {
2458         wfDeprecated( __FUNCTION__, '1.27' );
2459         $session = SessionManager::getGlobalSession();
2460         $delay = $session->delaySave();
2461
2462         $session->resetId();
2463
2464         // Make sure a session is started, since that's what the old
2465         // wfResetSessionID() did.
2466         if ( session_id() !== $session->getId() ) {
2467                 wfSetupSession( $session->getId() );
2468         }
2469
2470         ScopedCallback::consume( $delay );
2471 }
2472
2473 /**
2474  * Initialise php session
2475  *
2476  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2477  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2478  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2479  *  here), then calling $session->persist().
2480  * @param bool|string $sessionId
2481  */
2482 function wfSetupSession( $sessionId = false ) {
2483         wfDeprecated( __FUNCTION__, '1.27' );
2484
2485         if ( $sessionId ) {
2486                 session_id( $sessionId );
2487         }
2488
2489         $session = SessionManager::getGlobalSession();
2490         $session->persist();
2491
2492         if ( session_id() !== $session->getId() ) {
2493                 session_id( $session->getId() );
2494         }
2495         Wikimedia\quietCall( 'session_start' );
2496 }
2497
2498 /**
2499  * Get an object from the precompiled serialized directory
2500  *
2501  * @param string $name
2502  * @return mixed The variable on success, false on failure
2503  */
2504 function wfGetPrecompiledData( $name ) {
2505         global $IP;
2506
2507         $file = "$IP/serialized/$name";
2508         if ( file_exists( $file ) ) {
2509                 $blob = file_get_contents( $file );
2510                 if ( $blob ) {
2511                         return unserialize( $blob );
2512                 }
2513         }
2514         return false;
2515 }
2516
2517 /**
2518  * Make a cache key for the local wiki.
2519  *
2520  * @deprecated since 1.30 Call makeKey on a BagOStuff instance
2521  * @param string ...$args
2522  * @return string
2523  */
2524 function wfMemcKey( ...$args ) {
2525         return ObjectCache::getLocalClusterInstance()->makeKey( ...$args );
2526 }
2527
2528 /**
2529  * Make a cache key for a foreign DB.
2530  *
2531  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2532  *
2533  * @param string $db
2534  * @param string $prefix
2535  * @param string ...$args
2536  * @return string
2537  */
2538 function wfForeignMemcKey( $db, $prefix, ...$args ) {
2539         $keyspace = $prefix ? "$db-$prefix" : $db;
2540         return ObjectCache::getLocalClusterInstance()->makeKeyInternal( $keyspace, $args );
2541 }
2542
2543 /**
2544  * Make a cache key with database-agnostic prefix.
2545  *
2546  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
2547  * instead. Must have a prefix as otherwise keys that use a database name
2548  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
2549  *
2550  * @deprecated since 1.30 Call makeGlobalKey on a BagOStuff instance
2551  * @since 1.26
2552  * @param string ...$args
2553  * @return string
2554  */
2555 function wfGlobalCacheKey( ...$args ) {
2556         return ObjectCache::getLocalClusterInstance()->makeGlobalKey( ...$args );
2557 }
2558
2559 /**
2560  * Get an ASCII string identifying this wiki
2561  * This is used as a prefix in memcached keys
2562  *
2563  * @return string
2564  */
2565 function wfWikiID() {
2566         global $wgDBprefix, $wgDBname;
2567         if ( $wgDBprefix ) {
2568                 return "$wgDBname-$wgDBprefix";
2569         } else {
2570                 return $wgDBname;
2571         }
2572 }
2573
2574 /**
2575  * Get a Database object.
2576  *
2577  * @param int $db Index of the connection to get. May be DB_MASTER for the
2578  *            master (for write queries), DB_REPLICA for potentially lagged read
2579  *            queries, or an integer >= 0 for a particular server.
2580  *
2581  * @param string|string[] $groups Query groups. An array of group names that this query
2582  *                belongs to. May contain a single string if the query is only
2583  *                in one group.
2584  *
2585  * @param string|bool $wiki The wiki ID, or false for the current wiki
2586  *
2587  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
2588  * will always return the same object, unless the underlying connection or load
2589  * balancer is manually destroyed.
2590  *
2591  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
2592  * updater to ensure that a proper database is being updated.
2593  *
2594  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
2595  *       on an injected instance of LoadBalancer.
2596  *
2597  * @return \Wikimedia\Rdbms\Database
2598  */
2599 function wfGetDB( $db, $groups = [], $wiki = false ) {
2600         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
2601 }
2602
2603 /**
2604  * Get a load balancer object.
2605  *
2606  * @deprecated since 1.27, use MediaWikiServices::getInstance()->getDBLoadBalancer()
2607  *              or MediaWikiServices::getInstance()->getDBLoadBalancerFactory() instead.
2608  *
2609  * @param string|bool $wiki Wiki ID, or false for the current wiki
2610  * @return \Wikimedia\Rdbms\LoadBalancer
2611  */
2612 function wfGetLB( $wiki = false ) {
2613         if ( $wiki === false ) {
2614                 return MediaWikiServices::getInstance()->getDBLoadBalancer();
2615         } else {
2616                 $factory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2617                 return $factory->getMainLB( $wiki );
2618         }
2619 }
2620
2621 /**
2622  * Get the load balancer factory object
2623  *
2624  * @deprecated since 1.27, use MediaWikiServices::getInstance()->getDBLoadBalancerFactory() instead.
2625  * TODO: Remove in MediaWiki 1.35
2626  *
2627  * @return \Wikimedia\Rdbms\LBFactory
2628  */
2629 function wfGetLBFactory() {
2630         wfDeprecated( __METHOD__, '1.34' );
2631         return MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2632 }
2633
2634 /**
2635  * Find a file.
2636  * Shortcut for RepoGroup::singleton()->findFile()
2637  *
2638  * @param string|LinkTarget $title String or LinkTarget object
2639  * @param array $options Associative array of options (see RepoGroup::findFile)
2640  * @return File|bool File, or false if the file does not exist
2641  */
2642 function wfFindFile( $title, $options = [] ) {
2643         return RepoGroup::singleton()->findFile( $title, $options );
2644 }
2645
2646 /**
2647  * Get an object referring to a locally registered file.
2648  * Returns a valid placeholder object if the file does not exist.
2649  *
2650  * @param Title|string $title
2651  * @return LocalFile|null A File, or null if passed an invalid Title
2652  */
2653 function wfLocalFile( $title ) {
2654         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
2655 }
2656
2657 /**
2658  * Should low-performance queries be disabled?
2659  *
2660  * @return bool
2661  * @codeCoverageIgnore
2662  */
2663 function wfQueriesMustScale() {
2664         global $wgMiserMode;
2665         return $wgMiserMode
2666                 || ( SiteStats::pages() > 100000
2667                 && SiteStats::edits() > 1000000
2668                 && SiteStats::users() > 10000 );
2669 }
2670
2671 /**
2672  * Get the path to a specified script file, respecting file
2673  * extensions; this is a wrapper around $wgScriptPath etc.
2674  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
2675  *
2676  * @param string $script Script filename, sans extension
2677  * @return string
2678  */
2679 function wfScript( $script = 'index' ) {
2680         global $wgScriptPath, $wgScript, $wgLoadScript;
2681         if ( $script === 'index' ) {
2682                 return $wgScript;
2683         } elseif ( $script === 'load' ) {
2684                 return $wgLoadScript;
2685         } else {
2686                 return "{$wgScriptPath}/{$script}.php";
2687         }
2688 }
2689
2690 /**
2691  * Get the script URL.
2692  *
2693  * @return string Script URL
2694  */
2695 function wfGetScriptUrl() {
2696         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
2697                 /* as it was called, minus the query string.
2698                  *
2699                  * Some sites use Apache rewrite rules to handle subdomains,
2700                  * and have PHP set up in a weird way that causes PHP_SELF
2701                  * to contain the rewritten URL instead of the one that the
2702                  * outside world sees.
2703                  *
2704                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
2705                  * provides containing the "before" URL.
2706                  */
2707                 return $_SERVER['SCRIPT_NAME'];
2708         } else {
2709                 return $_SERVER['URL'];
2710         }
2711 }
2712
2713 /**
2714  * Convenience function converts boolean values into "true"
2715  * or "false" (string) values
2716  *
2717  * @param bool $value
2718  * @return string
2719  */
2720 function wfBoolToStr( $value ) {
2721         return $value ? 'true' : 'false';
2722 }
2723
2724 /**
2725  * Get a platform-independent path to the null file, e.g. /dev/null
2726  *
2727  * @return string
2728  */
2729 function wfGetNull() {
2730         return wfIsWindows() ? 'NUL' : '/dev/null';
2731 }
2732
2733 /**
2734  * Waits for the replica DBs to catch up to the master position
2735  *
2736  * Use this when updating very large numbers of rows, as in maintenance scripts,
2737  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
2738  *
2739  * By default this waits on the main DB cluster of the current wiki.
2740  * If $cluster is set to "*" it will wait on all DB clusters, including
2741  * external ones. If the lag being waiting on is caused by the code that
2742  * does this check, it makes since to use $ifWritesSince, particularly if
2743  * cluster is "*", to avoid excess overhead.
2744  *
2745  * Never call this function after a big DB write that is still in a transaction.
2746  * This only makes sense after the possible lag inducing changes were committed.
2747  *
2748  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
2749  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
2750  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
2751  * @param int|null $timeout Max wait time. Default: 60 seconds (cli), 1 second (web)
2752  * @return bool Success (able to connect and no timeouts reached)
2753  * @deprecated since 1.27 Use LBFactory::waitForReplication
2754  */
2755 function wfWaitForSlaves(
2756         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
2757 ) {
2758         $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2759
2760         if ( $cluster === '*' ) {
2761                 $cluster = false;
2762                 $domain = false;
2763         } elseif ( $wiki === false ) {
2764                 $domain = $lbFactory->getLocalDomainID();
2765         } else {
2766                 $domain = $wiki;
2767         }
2768
2769         $opts = [
2770                 'domain' => $domain,
2771                 'cluster' => $cluster,
2772                 // B/C: first argument used to be "max seconds of lag"; ignore such values
2773                 'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
2774         ];
2775         if ( $timeout !== null ) {
2776                 $opts['timeout'] = $timeout;
2777         }
2778
2779         return $lbFactory->waitForReplication( $opts );
2780 }
2781
2782 /**
2783  * Count down from $seconds to zero on the terminal, with a one-second pause
2784  * between showing each number. For use in command-line scripts.
2785  *
2786  * @deprecated since 1.31, use Maintenance::countDown()
2787  *
2788  * @codeCoverageIgnore
2789  * @param int $seconds
2790  */
2791 function wfCountDown( $seconds ) {
2792         wfDeprecated( __FUNCTION__, '1.31' );
2793         for ( $i = $seconds; $i >= 0; $i-- ) {
2794                 if ( $i != $seconds ) {
2795                         echo str_repeat( "\x08", strlen( $i + 1 ) );
2796                 }
2797                 echo $i;
2798                 flush();
2799                 if ( $i ) {
2800                         sleep( 1 );
2801                 }
2802         }
2803         echo "\n";
2804 }
2805
2806 /**
2807  * Replace all invalid characters with '-'.
2808  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
2809  * By default, $wgIllegalFileChars includes ':', '/', '\'.
2810  *
2811  * @param string $name Filename to process
2812  * @return string
2813  */
2814 function wfStripIllegalFilenameChars( $name ) {
2815         global $wgIllegalFileChars;
2816         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
2817         $name = preg_replace(
2818                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
2819                 '-',
2820                 $name
2821         );
2822         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
2823         $name = wfBaseName( $name );
2824         return $name;
2825 }
2826
2827 /**
2828  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
2829  *
2830  * @return int Resulting value of the memory limit.
2831  */
2832 function wfMemoryLimit() {
2833         global $wgMemoryLimit;
2834         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
2835         if ( $memlimit != -1 ) {
2836                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
2837                 if ( $conflimit == -1 ) {
2838                         wfDebug( "Removing PHP's memory limit\n" );
2839                         Wikimedia\suppressWarnings();
2840                         ini_set( 'memory_limit', $conflimit );
2841                         Wikimedia\restoreWarnings();
2842                         return $conflimit;
2843                 } elseif ( $conflimit > $memlimit ) {
2844                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
2845                         Wikimedia\suppressWarnings();
2846                         ini_set( 'memory_limit', $conflimit );
2847                         Wikimedia\restoreWarnings();
2848                         return $conflimit;
2849                 }
2850         }
2851         return $memlimit;
2852 }
2853
2854 /**
2855  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
2856  *
2857  * @return int Prior time limit
2858  * @since 1.26
2859  */
2860 function wfTransactionalTimeLimit() {
2861         global $wgTransactionalTimeLimit;
2862
2863         $timeLimit = ini_get( 'max_execution_time' );
2864         // Note that CLI scripts use 0
2865         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
2866                 set_time_limit( $wgTransactionalTimeLimit );
2867         }
2868
2869         ignore_user_abort( true ); // ignore client disconnects
2870
2871         return $timeLimit;
2872 }
2873
2874 /**
2875  * Converts shorthand byte notation to integer form
2876  *
2877  * @param string $string
2878  * @param int $default Returned if $string is empty
2879  * @return int
2880  */
2881 function wfShorthandToInteger( $string = '', $default = -1 ) {
2882         $string = trim( $string );
2883         if ( $string === '' ) {
2884                 return $default;
2885         }
2886         $last = $string[strlen( $string ) - 1];
2887         $val = intval( $string );
2888         switch ( $last ) {
2889                 case 'g':
2890                 case 'G':
2891                         $val *= 1024;
2892                         // break intentionally missing
2893                 case 'm':
2894                 case 'M':
2895                         $val *= 1024;
2896                         // break intentionally missing
2897                 case 'k':
2898                 case 'K':
2899                         $val *= 1024;
2900         }
2901
2902         return $val;
2903 }
2904
2905 /**
2906  * Get the normalised IETF language tag
2907  * See unit test for examples.
2908  * See mediawiki.language.bcp47 for the JavaScript implementation.
2909  *
2910  * @deprecated since 1.31, use LanguageCode::bcp47() directly.
2911  *
2912  * @param string $code The language code.
2913  * @return string The language code which complying with BCP 47 standards.
2914  */
2915 function wfBCP47( $code ) {
2916         wfDeprecated( __METHOD__, '1.31' );
2917         return LanguageCode::bcp47( $code );
2918 }
2919
2920 /**
2921  * Get a specific cache object.
2922  *
2923  * @deprecated since 1.32, use ObjectCache::getInstance() instead
2924  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
2925  * @return BagOStuff
2926  */
2927 function wfGetCache( $cacheType ) {
2928         return ObjectCache::getInstance( $cacheType );
2929 }
2930
2931 /**
2932  * Get the main cache object
2933  *
2934  * @deprecated since 1.32, use ObjectCache::getLocalClusterInstance() instead
2935  * @return BagOStuff
2936  */
2937 function wfGetMainCache() {
2938         return ObjectCache::getLocalClusterInstance();
2939 }
2940
2941 /**
2942  * Get the cache object used by the message cache
2943  *
2944  * @return BagOStuff
2945  */
2946 function wfGetMessageCacheStorage() {
2947         global $wgMessageCacheType;
2948         return ObjectCache::getInstance( $wgMessageCacheType );
2949 }
2950
2951 /**
2952  * Wrapper around php's unpack.
2953  *
2954  * @param string $format The format string (See php's docs)
2955  * @param string $data A binary string of binary data
2956  * @param int|bool $length The minimum length of $data or false. This is to
2957  *      prevent reading beyond the end of $data. false to disable the check.
2958  *
2959  * Also be careful when using this function to read unsigned 32 bit integer
2960  * because php might make it negative.
2961  *
2962  * @throws MWException If $data not long enough, or if unpack fails
2963  * @return array Associative array of the extracted data
2964  */
2965 function wfUnpack( $format, $data, $length = false ) {
2966         if ( $length !== false ) {
2967                 $realLen = strlen( $data );
2968                 if ( $realLen < $length ) {
2969                         throw new MWException( "Tried to use wfUnpack on a "
2970                                 . "string of length $realLen, but needed one "
2971                                 . "of at least length $length."
2972                         );
2973                 }
2974         }
2975
2976         Wikimedia\suppressWarnings();
2977         $result = unpack( $format, $data );
2978         Wikimedia\restoreWarnings();
2979
2980         if ( $result === false ) {
2981                 // If it cannot extract the packed data.
2982                 throw new MWException( "unpack could not unpack binary data" );
2983         }
2984         return $result;
2985 }
2986
2987 /**
2988  * Determine if an image exists on the 'bad image list'.
2989  *
2990  * The format of MediaWiki:Bad_image_list is as follows:
2991  *    * Only list items (lines starting with "*") are considered
2992  *    * The first link on a line must be a link to a bad image
2993  *    * Any subsequent links on the same line are considered to be exceptions,
2994  *      i.e. articles where the image may occur inline.
2995  *
2996  * @param string $name The image name to check
2997  * @param Title|bool $contextTitle The page on which the image occurs, if known
2998  * @param string|null $blacklist Wikitext of a file blacklist
2999  * @return bool
3000  */
3001 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3002         # Handle redirects; callers almost always hit wfFindFile() anyway,
3003         # so just use that method because it has a fast process cache.
3004         $file = wfFindFile( $name ); // get the final name
3005         $name = $file ? $file->getTitle()->getDBkey() : $name;
3006
3007         # Run the extension hook
3008         $bad = false;
3009         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3010                 return (bool)$bad;
3011         }
3012
3013         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3014         $key = $cache->makeKey(
3015                 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist )
3016         );
3017         $badImages = $cache->get( $key );
3018
3019         if ( $badImages === false ) { // cache miss
3020                 if ( $blacklist === null ) {
3021                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3022                 }
3023                 # Build the list now
3024                 $badImages = [];
3025                 $lines = explode( "\n", $blacklist );
3026                 foreach ( $lines as $line ) {
3027                         # List items only
3028                         if ( substr( $line, 0, 1 ) !== '*' ) {
3029                                 continue;
3030                         }
3031
3032                         # Find all links
3033                         $m = [];
3034                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3035                                 continue;
3036                         }
3037
3038                         $exceptions = [];
3039                         $imageDBkey = false;
3040                         foreach ( $m[1] as $i => $titleText ) {
3041                                 $title = Title::newFromText( $titleText );
3042                                 if ( !is_null( $title ) ) {
3043                                         if ( $i == 0 ) {
3044                                                 $imageDBkey = $title->getDBkey();
3045                                         } else {
3046                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3047                                         }
3048                                 }
3049                         }
3050
3051                         if ( $imageDBkey !== false ) {
3052                                 $badImages[$imageDBkey] = $exceptions;
3053                         }
3054                 }
3055                 $cache->set( $key, $badImages, 60 );
3056         }
3057
3058         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3059         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3060
3061         return $bad;
3062 }
3063
3064 /**
3065  * Determine whether the client at a given source IP is likely to be able to
3066  * access the wiki via HTTPS.
3067  *
3068  * @param string $ip The IPv4/6 address in the normal human-readable form
3069  * @return bool
3070  */
3071 function wfCanIPUseHTTPS( $ip ) {
3072         $canDo = true;
3073         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3074         return (bool)$canDo;
3075 }
3076
3077 /**
3078  * Determine input string is represents as infinity
3079  *
3080  * @param string $str The string to determine
3081  * @return bool
3082  * @since 1.25
3083  */
3084 function wfIsInfinity( $str ) {
3085         // These are hardcoded elsewhere in MediaWiki (e.g. mediawiki.special.block.js).
3086         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3087         return in_array( $str, $infinityValues );
3088 }
3089
3090 /**
3091  * Returns true if these thumbnail parameters match one that MediaWiki
3092  * requests from file description pages and/or parser output.
3093  *
3094  * $params is considered non-standard if they involve a non-standard
3095  * width or any non-default parameters aside from width and page number.
3096  * The number of possible files with standard parameters is far less than
3097  * that of all combinations; rate-limiting for them can thus be more generious.
3098  *
3099  * @param File $file
3100  * @param array $params
3101  * @return bool
3102  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3103  */
3104 function wfThumbIsStandard( File $file, array $params ) {
3105         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3106
3107         $multipliers = [ 1 ];
3108         if ( $wgResponsiveImages ) {
3109                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3110                 // @see Linker::processResponsiveImages
3111                 $multipliers[] = 1.5;
3112                 $multipliers[] = 2;
3113         }
3114
3115         $handler = $file->getHandler();
3116         if ( !$handler || !isset( $params['width'] ) ) {
3117                 return false;
3118         }
3119
3120         $basicParams = [];
3121         if ( isset( $params['page'] ) ) {
3122                 $basicParams['page'] = $params['page'];
3123         }
3124
3125         $thumbLimits = [];
3126         $imageLimits = [];
3127         // Expand limits to account for multipliers
3128         foreach ( $multipliers as $multiplier ) {
3129                 $thumbLimits = array_merge( $thumbLimits, array_map(
3130                         function ( $width ) use ( $multiplier ) {
3131                                 return round( $width * $multiplier );
3132                         }, $wgThumbLimits )
3133                 );
3134                 $imageLimits = array_merge( $imageLimits, array_map(
3135                         function ( $pair ) use ( $multiplier ) {
3136                                 return [
3137                                         round( $pair[0] * $multiplier ),
3138                                         round( $pair[1] * $multiplier ),
3139                                 ];
3140                         }, $wgImageLimits )
3141                 );
3142         }
3143
3144         // Check if the width matches one of $wgThumbLimits
3145         if ( in_array( $params['width'], $thumbLimits ) ) {
3146                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3147                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3148                 $handler->normaliseParams( $file, $normalParams );
3149         } else {
3150                 // If not, then check if the width matchs one of $wgImageLimits
3151                 $match = false;
3152                 foreach ( $imageLimits as $pair ) {
3153                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3154                         // Decide whether the thumbnail should be scaled on width or height.
3155                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3156                         $handler->normaliseParams( $file, $normalParams );
3157                         // Check if this standard thumbnail size maps to the given width
3158                         if ( $normalParams['width'] == $params['width'] ) {
3159                                 $match = true;
3160                                 break;
3161                         }
3162                 }
3163                 if ( !$match ) {
3164                         return false; // not standard for description pages
3165                 }
3166         }
3167
3168         // Check that the given values for non-page, non-width, params are just defaults
3169         foreach ( $params as $key => $value ) {
3170                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3171                         return false;
3172                 }
3173         }
3174
3175         return true;
3176 }
3177
3178 /**
3179  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3180  *
3181  * Values that exist in both values will be combined with += (all values of the array
3182  * of $newValues will be added to the values of the array of $baseArray, while values,
3183  * that exists in both, the value of $baseArray will be used).
3184  *
3185  * @param array $baseArray The array where you want to add the values of $newValues to
3186  * @param array $newValues An array with new values
3187  * @return array The combined array
3188  * @since 1.26
3189  */
3190 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3191         // First merge items that are in both arrays
3192         foreach ( $baseArray as $name => &$groupVal ) {
3193                 if ( isset( $newValues[$name] ) ) {
3194                         $groupVal += $newValues[$name];
3195                 }
3196         }
3197         // Now add items that didn't exist yet
3198         $baseArray += $newValues;
3199
3200         return $baseArray;
3201 }
3202
3203 /**
3204  * Get system resource usage of current request context.
3205  * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
3206  * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
3207  *
3208  * @since 1.24
3209  * @return array|bool Resource usage data or false if no data available.
3210  */
3211 function wfGetRusage() {
3212         if ( !function_exists( 'getrusage' ) ) {
3213                 return false;
3214         } elseif ( defined( 'HHVM_VERSION' ) && PHP_OS === 'Linux' ) {
3215                 return getrusage( 2 /* RUSAGE_THREAD */ );
3216         } else {
3217                 return getrusage( 0 /* RUSAGE_SELF */ );
3218         }
3219 }