includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 use MediaWiki\Logger\LoggerFactory;
  28 use MediaWiki\ProcOpenError;
  29 use MediaWiki\Session\SessionManager;
  30 use MediaWiki\MediaWikiServices;
  31 use MediaWiki\Shell\Shell;
  32 use Wikimedia\ScopedCallback;
  33 use Wikimedia\Rdbms\DBReplicationWaitError;
  34
  35 // Hide compatibility functions from Doxygen
  36 /// @cond
  37 /**
  38  * Compatibility functions
  39  *
  40  * We support PHP 5.5.9 and up.
  41  * Re-implementations of newer functions or functions in non-standard
  42  * PHP extensions may be included here.
  43  */
  44
  45 // hash_equals function only exists in PHP >= 5.6.0
  46 // https://secure.php.net/hash_equals
  47 if ( !function_exists( 'hash_equals' ) ) {
  48         /**
  49          * Check whether a user-provided string is equal to a fixed-length secret string
  50          * without revealing bytes of the secret string through timing differences.
  51          *
  52          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
  53          * function in C) is to compare corresponding bytes and stop at the first difference,
  54          * which would take longer for a partial match than for a complete mismatch. This
  55          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
  56          * and the other may come from an attacker. Statistical analysis of timing measurements
  57          * over many requests may allow the attacker to guess the string's bytes one at a time
  58          * (and check his guesses) even if the timing differences are extremely small.
  59          *
  60          * When making such a security-sensitive comparison, it is essential that the sequence
  61          * in which instructions are executed and memory locations are accessed not depend on
  62          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
  63          * the inevitable leakage of the string's length. That is generally known anyway as
  64          * a chararacteristic of the hash function used to compute the secret value.
  65          *
  66          * Longer explanation: http://www.emerose.com/timing-attacks-explained
  67          *
  68          * @codeCoverageIgnore
  69          * @param string $known_string Fixed-length secret string to compare against
  70          * @param string $user_string User-provided string
  71          * @return bool True if the strings are the same, false otherwise
  72          */
  73         function hash_equals( $known_string, $user_string ) {
  74                 // Strict type checking as in PHP's native implementation
  75                 if ( !is_string( $known_string ) ) {
  76                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
  77                                 gettype( $known_string ) . ' given', E_USER_WARNING );
  78
  79                         return false;
  80                 }
  81
  82                 if ( !is_string( $user_string ) ) {
  83                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
  84                                 gettype( $user_string ) . ' given', E_USER_WARNING );
  85
  86                         return false;
  87                 }
  88
  89                 $known_string_len = strlen( $known_string );
  90                 if ( $known_string_len !== strlen( $user_string ) ) {
  91                         return false;
  92                 }
  93
  94                 $result = 0;
  95                 for ( $i = 0; $i < $known_string_len; $i++ ) {
  96                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
  97                 }
  98
  99                 return ( $result === 0 );
 100         }
 101 }
 102 /// @endcond
 103
 104 /**
 105  * Load an extension
 106  *
 107  * This queues an extension to be loaded through
 108  * the ExtensionRegistry system.
 109  *
 110  * @param string $ext Name of the extension to load
 111  * @param string|null $path Absolute path of where to find the extension.json file
 112  * @since 1.25
 113  */
 114 function wfLoadExtension( $ext, $path = null ) {
 115         if ( !$path ) {
 116                 global $wgExtensionDirectory;
 117                 $path = "$wgExtensionDirectory/$ext/extension.json";
 118         }
 119         ExtensionRegistry::getInstance()->queue( $path );
 120 }
 121
 122 /**
 123  * Load multiple extensions at once
 124  *
 125  * Same as wfLoadExtension, but more efficient if you
 126  * are loading multiple extensions.
 127  *
 128  * If you want to specify custom paths, you should interact with
 129  * ExtensionRegistry directly.
 130  *
 131  * @see wfLoadExtension
 132  * @param string[] $exts Array of extension names to load
 133  * @since 1.25
 134  */
 135 function wfLoadExtensions( array $exts ) {
 136         global $wgExtensionDirectory;
 137         $registry = ExtensionRegistry::getInstance();
 138         foreach ( $exts as $ext ) {
 139                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 140         }
 141 }
 142
 143 /**
 144  * Load a skin
 145  *
 146  * @see wfLoadExtension
 147  * @param string $skin Name of the extension to load
 148  * @param string|null $path Absolute path of where to find the skin.json file
 149  * @since 1.25
 150  */
 151 function wfLoadSkin( $skin, $path = null ) {
 152         if ( !$path ) {
 153                 global $wgStyleDirectory;
 154                 $path = "$wgStyleDirectory/$skin/skin.json";
 155         }
 156         ExtensionRegistry::getInstance()->queue( $path );
 157 }
 158
 159 /**
 160  * Load multiple skins at once
 161  *
 162  * @see wfLoadExtensions
 163  * @param string[] $skins Array of extension names to load
 164  * @since 1.25
 165  */
 166 function wfLoadSkins( array $skins ) {
 167         global $wgStyleDirectory;
 168         $registry = ExtensionRegistry::getInstance();
 169         foreach ( $skins as $skin ) {
 170                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 171         }
 172 }
 173
 174 /**
 175  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 176  * @param array $a
 177  * @param array $b
 178  * @return array
 179  */
 180 function wfArrayDiff2( $a, $b ) {
 181         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 182 }
 183
 184 /**
 185  * @param array|string $a
 186  * @param array|string $b
 187  * @return int
 188  */
 189 function wfArrayDiff2_cmp( $a, $b ) {
 190         if ( is_string( $a ) && is_string( $b ) ) {
 191                 return strcmp( $a, $b );
 192         } elseif ( count( $a ) !== count( $b ) ) {
 193                 return count( $a ) < count( $b ) ? -1 : 1;
 194         } else {
 195                 reset( $a );
 196                 reset( $b );
 197                 while ( key( $a ) !== null && key( $b ) !== null ) {
 198                         $valueA = current( $a );
 199                         $valueB = current( $b );
 200                         $cmp = strcmp( $valueA, $valueB );
 201                         if ( $cmp !== 0 ) {
 202                                 return $cmp;
 203                         }
 204                         next( $a );
 205                         next( $b );
 206                 }
 207                 return 0;
 208         }
 209 }
 210
 211 /**
 212  * Like array_filter with ARRAY_FILTER_USE_BOTH, but works pre-5.6.
 213  *
 214  * @param array $arr
 215  * @param callable $callback Will be called with the array value and key (in that order) and
 216  *   should return a bool which will determine whether the array element is kept.
 217  * @return array
 218  */
 219 function wfArrayFilter( array $arr, callable $callback ) {
 220         if ( defined( 'ARRAY_FILTER_USE_BOTH' ) ) {
 221                 return array_filter( $arr, $callback, ARRAY_FILTER_USE_BOTH );
 222         }
 223         $filteredKeys = array_filter( array_keys( $arr ), function ( $key ) use ( $arr, $callback ) {
 224                 return call_user_func( $callback, $arr[$key], $key );
 225         } );
 226         return array_intersect_key( $arr, array_fill_keys( $filteredKeys, true ) );
 227 }
 228
 229 /**
 230  * Like array_filter with ARRAY_FILTER_USE_KEY, but works pre-5.6.
 231  *
 232  * @param array $arr
 233  * @param callable $callback Will be called with the array key and should return a bool which
 234  *   will determine whether the array element is kept.
 235  * @return array
 236  */
 237 function wfArrayFilterByKey( array $arr, callable $callback ) {
 238         return wfArrayFilter( $arr, function ( $val, $key ) use ( $callback ) {
 239                 return call_user_func( $callback, $key );
 240         } );
 241 }
 242
 243 /**
 244  * Appends to second array if $value differs from that in $default
 245  *
 246  * @param string|int $key
 247  * @param mixed $value
 248  * @param mixed $default
 249  * @param array &$changed Array to alter
 250  * @throws MWException
 251  */
 252 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 253         if ( is_null( $changed ) ) {
 254                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 255         }
 256         if ( $default[$key] !== $value ) {
 257                 $changed[$key] = $value;
 258         }
 259 }
 260
 261 /**
 262  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 263  * e.g.
 264  *     wfMergeErrorArrays(
 265  *       [ [ 'x' ] ],
 266  *       [ [ 'x', '2' ] ],
 267  *       [ [ 'x' ] ],
 268  *       [ [ 'y' ] ]
 269  *     );
 270  * returns:
 271  *     [
 272  *       [ 'x', '2' ],
 273  *       [ 'x' ],
 274  *       [ 'y' ]
 275  *     ]
 276  *
 277  * @param array $array1,...
 278  * @return array
 279  */
 280 function wfMergeErrorArrays( /*...*/ ) {
 281         $args = func_get_args();
 282         $out = [];
 283         foreach ( $args as $errors ) {
 284                 foreach ( $errors as $params ) {
 285                         $originalParams = $params;
 286                         if ( $params[0] instanceof MessageSpecifier ) {
 287                                 $msg = $params[0];
 288                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 289                         }
 290                         # @todo FIXME: Sometimes get nested arrays for $params,
 291                         # which leads to E_NOTICEs
 292                         $spec = implode( "\t", $params );
 293                         $out[$spec] = $originalParams;
 294                 }
 295         }
 296         return array_values( $out );
 297 }
 298
 299 /**
 300  * Insert array into another array after the specified *KEY*
 301  *
 302  * @param array $array The array.
 303  * @param array $insert The array to insert.
 304  * @param mixed $after The key to insert after
 305  * @return array
 306  */
 307 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 308         // Find the offset of the element to insert after.
 309         $keys = array_keys( $array );
 310         $offsetByKey = array_flip( $keys );
 311
 312         $offset = $offsetByKey[$after];
 313
 314         // Insert at the specified offset
 315         $before = array_slice( $array, 0, $offset + 1, true );
 316         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 317
 318         $output = $before + $insert + $after;
 319
 320         return $output;
 321 }
 322
 323 /**
 324  * Recursively converts the parameter (an object) to an array with the same data
 325  *
 326  * @param object|array $objOrArray
 327  * @param bool $recursive
 328  * @return array
 329  */
 330 function wfObjectToArray( $objOrArray, $recursive = true ) {
 331         $array = [];
 332         if ( is_object( $objOrArray ) ) {
 333                 $objOrArray = get_object_vars( $objOrArray );
 334         }
 335         foreach ( $objOrArray as $key => $value ) {
 336                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 337                         $value = wfObjectToArray( $value );
 338                 }
 339
 340                 $array[$key] = $value;
 341         }
 342
 343         return $array;
 344 }
 345
 346 /**
 347  * Get a random decimal value between 0 and 1, in a way
 348  * not likely to give duplicate values for any realistic
 349  * number of articles.
 350  *
 351  * @note This is designed for use in relation to Special:RandomPage
 352  *       and the page_random database field.
 353  *
 354  * @return string
 355  */
 356 function wfRandom() {
 357         // The maximum random value is "only" 2^31-1, so get two random
 358         // values to reduce the chance of dupes
 359         $max = mt_getrandmax() + 1;
 360         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 361         return $rand;
 362 }
 363
 364 /**
 365  * Get a random string containing a number of pseudo-random hex characters.
 366  *
 367  * @note This is not secure, if you are trying to generate some sort
 368  *       of token please use MWCryptRand instead.
 369  *
 370  * @param int $length The length of the string to generate
 371  * @return string
 372  * @since 1.20
 373  */
 374 function wfRandomString( $length = 32 ) {
 375         $str = '';
 376         for ( $n = 0; $n < $length; $n += 7 ) {
 377                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 378         }
 379         return substr( $str, 0, $length );
 380 }
 381
 382 /**
 383  * We want some things to be included as literal characters in our title URLs
 384  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 385  * all of the following should be safe:
 386  *
 387  * ;:@&=$-_.+!*'(),
 388  *
 389  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 390  * character which should not be encoded. More importantly, google chrome
 391  * always converts %7E back to ~, and converting it in this function can
 392  * cause a redirect loop (T105265).
 393  *
 394  * But + is not safe because it's used to indicate a space; &= are only safe in
 395  * paths and not in queries (and we don't distinguish here); ' seems kind of
 396  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 397  * is reserved, we don't care.  So the list we unescape is:
 398  *
 399  * ;:@$!*(),/~
 400  *
 401  * However, IIS7 redirects fail when the url contains a colon (see T24709),
 402  * so no fancy : for IIS7.
 403  *
 404  * %2F in the page titles seems to fatally break for some reason.
 405  *
 406  * @param string $s
 407  * @return string
 408  */
 409 function wfUrlencode( $s ) {
 410         static $needle;
 411
 412         if ( is_null( $s ) ) {
 413                 $needle = null;
 414                 return '';
 415         }
 416
 417         if ( is_null( $needle ) ) {
 418                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 419                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 420                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 421                 ) {
 422                         $needle[] = '%3A';
 423                 }
 424         }
 425
 426         $s = urlencode( $s );
 427         $s = str_ireplace(
 428                 $needle,
 429                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 430                 $s
 431         );
 432
 433         return $s;
 434 }
 435
 436 /**
 437  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 438  * "days=7&limit=100". Options in the first array override options in the second.
 439  * Options set to null or false will not be output.
 440  *
 441  * @param array $array1 ( String|Array )
 442  * @param array|null $array2 ( String|Array )
 443  * @param string $prefix
 444  * @return string
 445  */
 446 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 447         if ( !is_null( $array2 ) ) {
 448                 $array1 = $array1 + $array2;
 449         }
 450
 451         $cgi = '';
 452         foreach ( $array1 as $key => $value ) {
 453                 if ( !is_null( $value ) && $value !== false ) {
 454                         if ( $cgi != '' ) {
 455                                 $cgi .= '&';
 456                         }
 457                         if ( $prefix !== '' ) {
 458                                 $key = $prefix . "[$key]";
 459                         }
 460                         if ( is_array( $value ) ) {
 461                                 $firstTime = true;
 462                                 foreach ( $value as $k => $v ) {
 463                                         $cgi .= $firstTime ? '' : '&';
 464                                         if ( is_array( $v ) ) {
 465                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 466                                         } else {
 467                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 468                                         }
 469                                         $firstTime = false;
 470                                 }
 471                         } else {
 472                                 if ( is_object( $value ) ) {
 473                                         $value = $value->__toString();
 474                                 }
 475                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 476                         }
 477                 }
 478         }
 479         return $cgi;
 480 }
 481
 482 /**
 483  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 484  * its argument and returns the same string in array form.  This allows compatibility
 485  * with legacy functions that accept raw query strings instead of nice
 486  * arrays.  Of course, keys and values are urldecode()d.
 487  *
 488  * @param string $query Query string
 489  * @return string[] Array version of input
 490  */
 491 function wfCgiToArray( $query ) {
 492         if ( isset( $query[0] ) && $query[0] == '?' ) {
 493                 $query = substr( $query, 1 );
 494         }
 495         $bits = explode( '&', $query );
 496         $ret = [];
 497         foreach ( $bits as $bit ) {
 498                 if ( $bit === '' ) {
 499                         continue;
 500                 }
 501                 if ( strpos( $bit, '=' ) === false ) {
 502                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 503                         $key = $bit;
 504                         $value = '';
 505                 } else {
 506                         list( $key, $value ) = explode( '=', $bit );
 507                 }
 508                 $key = urldecode( $key );
 509                 $value = urldecode( $value );
 510                 if ( strpos( $key, '[' ) !== false ) {
 511                         $keys = array_reverse( explode( '[', $key ) );
 512                         $key = array_pop( $keys );
 513                         $temp = $value;
 514                         foreach ( $keys as $k ) {
 515                                 $k = substr( $k, 0, -1 );
 516                                 $temp = [ $k => $temp ];
 517                         }
 518                         if ( isset( $ret[$key] ) ) {
 519                                 $ret[$key] = array_merge( $ret[$key], $temp );
 520                         } else {
 521                                 $ret[$key] = $temp;
 522                         }
 523                 } else {
 524                         $ret[$key] = $value;
 525                 }
 526         }
 527         return $ret;
 528 }
 529
 530 /**
 531  * Append a query string to an existing URL, which may or may not already
 532  * have query string parameters already. If so, they will be combined.
 533  *
 534  * @param string $url
 535  * @param string|string[] $query String or associative array
 536  * @return string
 537  */
 538 function wfAppendQuery( $url, $query ) {
 539         if ( is_array( $query ) ) {
 540                 $query = wfArrayToCgi( $query );
 541         }
 542         if ( $query != '' ) {
 543                 // Remove the fragment, if there is one
 544                 $fragment = false;
 545                 $hashPos = strpos( $url, '#' );
 546                 if ( $hashPos !== false ) {
 547                         $fragment = substr( $url, $hashPos );
 548                         $url = substr( $url, 0, $hashPos );
 549                 }
 550
 551                 // Add parameter
 552                 if ( false === strpos( $url, '?' ) ) {
 553                         $url .= '?';
 554                 } else {
 555                         $url .= '&';
 556                 }
 557                 $url .= $query;
 558
 559                 // Put the fragment back
 560                 if ( $fragment !== false ) {
 561                         $url .= $fragment;
 562                 }
 563         }
 564         return $url;
 565 }
 566
 567 /**
 568  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 569  * is correct.
 570  *
 571  * The meaning of the PROTO_* constants is as follows:
 572  * PROTO_HTTP: Output a URL starting with http://
 573  * PROTO_HTTPS: Output a URL starting with https://
 574  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 575  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 576  *    on which protocol was used for the current incoming request
 577  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 578  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 579  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 580  *
 581  * @todo this won't work with current-path-relative URLs
 582  * like "subdir/foo.html", etc.
 583  *
 584  * @param string $url Either fully-qualified or a local path + query
 585  * @param string|int|null $defaultProto One of the PROTO_* constants. Determines the
 586  *    protocol to use if $url or $wgServer is protocol-relative
 587  * @return string|false Fully-qualified URL, current-path-relative URL or false if
 588  *    no valid URL can be constructed
 589  */
 590 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 591         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 592                 $wgHttpsPort;
 593         if ( $defaultProto === PROTO_CANONICAL ) {
 594                 $serverUrl = $wgCanonicalServer;
 595         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 596                 // Make $wgInternalServer fall back to $wgServer if not set
 597                 $serverUrl = $wgInternalServer;
 598         } else {
 599                 $serverUrl = $wgServer;
 600                 if ( $defaultProto === PROTO_CURRENT ) {
 601                         $defaultProto = $wgRequest->getProtocol() . '://';
 602                 }
 603         }
 604
 605         // Analyze $serverUrl to obtain its protocol
 606         $bits = wfParseUrl( $serverUrl );
 607         $serverHasProto = $bits && $bits['scheme'] != '';
 608
 609         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 610                 if ( $serverHasProto ) {
 611                         $defaultProto = $bits['scheme'] . '://';
 612                 } else {
 613                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 614                         // This really isn't supposed to happen. Fall back to HTTP in this
 615                         // ridiculous case.
 616                         $defaultProto = PROTO_HTTP;
 617                 }
 618         }
 619
 620         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 621
 622         if ( substr( $url, 0, 2 ) == '//' ) {
 623                 $url = $defaultProtoWithoutSlashes . $url;
 624         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 625                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 626                 // otherwise leave it alone.
 627                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 628         }
 629
 630         $bits = wfParseUrl( $url );
 631
 632         // ensure proper port for HTTPS arrives in URL
 633         // https://phabricator.wikimedia.org/T67184
 634         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 635                 $bits['port'] = $wgHttpsPort;
 636         }
 637
 638         if ( $bits && isset( $bits['path'] ) ) {
 639                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 640                 return wfAssembleUrl( $bits );
 641         } elseif ( $bits ) {
 642                 # No path to expand
 643                 return $url;
 644         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 645                 # URL is a relative path
 646                 return wfRemoveDotSegments( $url );
 647         }
 648
 649         # Expanded URL is not valid.
 650         return false;
 651 }
 652
 653 /**
 654  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 655  * if you need to edit part of a URL and put it back together.
 656  *
 657  * This is the basic structure used (brackets contain keys for $urlParts):
 658  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 659  *
 660  * @todo Need to integrate this into wfExpandUrl (see T34168)
 661  *
 662  * @since 1.19
 663  * @param array $urlParts URL parts, as output from wfParseUrl
 664  * @return string URL assembled from its component parts
 665  */
 666 function wfAssembleUrl( $urlParts ) {
 667         $result = '';
 668
 669         if ( isset( $urlParts['delimiter'] ) ) {
 670                 if ( isset( $urlParts['scheme'] ) ) {
 671                         $result .= $urlParts['scheme'];
 672                 }
 673
 674                 $result .= $urlParts['delimiter'];
 675         }
 676
 677         if ( isset( $urlParts['host'] ) ) {
 678                 if ( isset( $urlParts['user'] ) ) {
 679                         $result .= $urlParts['user'];
 680                         if ( isset( $urlParts['pass'] ) ) {
 681                                 $result .= ':' . $urlParts['pass'];
 682                         }
 683                         $result .= '@';
 684                 }
 685
 686                 $result .= $urlParts['host'];
 687
 688                 if ( isset( $urlParts['port'] ) ) {
 689                         $result .= ':' . $urlParts['port'];
 690                 }
 691         }
 692
 693         if ( isset( $urlParts['path'] ) ) {
 694                 $result .= $urlParts['path'];
 695         }
 696
 697         if ( isset( $urlParts['query'] ) ) {
 698                 $result .= '?' . $urlParts['query'];
 699         }
 700
 701         if ( isset( $urlParts['fragment'] ) ) {
 702                 $result .= '#' . $urlParts['fragment'];
 703         }
 704
 705         return $result;
 706 }
 707
 708 /**
 709  * Remove all dot-segments in the provided URL path.  For example,
 710  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 711  * RFC3986 section 5.2.4.
 712  *
 713  * @todo Need to integrate this into wfExpandUrl (see T34168)
 714  *
 715  * @param string $urlPath URL path, potentially containing dot-segments
 716  * @return string URL path with all dot-segments removed
 717  */
 718 function wfRemoveDotSegments( $urlPath ) {
 719         $output = '';
 720         $inputOffset = 0;
 721         $inputLength = strlen( $urlPath );
 722
 723         while ( $inputOffset < $inputLength ) {
 724                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 725                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 726                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 727                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 728                 $trimOutput = false;
 729
 730                 if ( $prefixLengthTwo == './' ) {
 731                         # Step A, remove leading "./"
 732                         $inputOffset += 2;
 733                 } elseif ( $prefixLengthThree == '../' ) {
 734                         # Step A, remove leading "../"
 735                         $inputOffset += 3;
 736                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 737                         # Step B, replace leading "/.$" with "/"
 738                         $inputOffset += 1;
 739                         $urlPath[$inputOffset] = '/';
 740                 } elseif ( $prefixLengthThree == '/./' ) {
 741                         # Step B, replace leading "/./" with "/"
 742                         $inputOffset += 2;
 743                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 744                         # Step C, replace leading "/..$" with "/" and
 745                         # remove last path component in output
 746                         $inputOffset += 2;
 747                         $urlPath[$inputOffset] = '/';
 748                         $trimOutput = true;
 749                 } elseif ( $prefixLengthFour == '/../' ) {
 750                         # Step C, replace leading "/../" with "/" and
 751                         # remove last path component in output
 752                         $inputOffset += 3;
 753                         $trimOutput = true;
 754                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 755                         # Step D, remove "^.$"
 756                         $inputOffset += 1;
 757                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 758                         # Step D, remove "^..$"
 759                         $inputOffset += 2;
 760                 } else {
 761                         # Step E, move leading path segment to output
 762                         if ( $prefixLengthOne == '/' ) {
 763                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 764                         } else {
 765                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 766                         }
 767                         if ( $slashPos === false ) {
 768                                 $output .= substr( $urlPath, $inputOffset );
 769                                 $inputOffset = $inputLength;
 770                         } else {
 771                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 772                                 $inputOffset += $slashPos - $inputOffset;
 773                         }
 774                 }
 775
 776                 if ( $trimOutput ) {
 777                         $slashPos = strrpos( $output, '/' );
 778                         if ( $slashPos === false ) {
 779                                 $output = '';
 780                         } else {
 781                                 $output = substr( $output, 0, $slashPos );
 782                         }
 783                 }
 784         }
 785
 786         return $output;
 787 }
 788
 789 /**
 790  * Returns a regular expression of url protocols
 791  *
 792  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 793  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 794  * @return string
 795  */
 796 function wfUrlProtocols( $includeProtocolRelative = true ) {
 797         global $wgUrlProtocols;
 798
 799         // Cache return values separately based on $includeProtocolRelative
 800         static $withProtRel = null, $withoutProtRel = null;
 801         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 802         if ( !is_null( $cachedValue ) ) {
 803                 return $cachedValue;
 804         }
 805
 806         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 807         // with LocalSettings files from 1.5
 808         if ( is_array( $wgUrlProtocols ) ) {
 809                 $protocols = [];
 810                 foreach ( $wgUrlProtocols as $protocol ) {
 811                         // Filter out '//' if !$includeProtocolRelative
 812                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 813                                 $protocols[] = preg_quote( $protocol, '/' );
 814                         }
 815                 }
 816
 817                 $retval = implode( '|', $protocols );
 818         } else {
 819                 // Ignore $includeProtocolRelative in this case
 820                 // This case exists for pre-1.6 compatibility, and we can safely assume
 821                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 822                 // URLs weren't supported until 1.18
 823                 $retval = $wgUrlProtocols;
 824         }
 825
 826         // Cache return value
 827         if ( $includeProtocolRelative ) {
 828                 $withProtRel = $retval;
 829         } else {
 830                 $withoutProtRel = $retval;
 831         }
 832         return $retval;
 833 }
 834
 835 /**
 836  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 837  * you need a regex that matches all URL protocols but does not match protocol-
 838  * relative URLs
 839  * @return string
 840  */
 841 function wfUrlProtocolsWithoutProtRel() {
 842         return wfUrlProtocols( false );
 843 }
 844
 845 /**
 846  * parse_url() work-alike, but non-broken.  Differences:
 847  *
 848  * 1) Does not raise warnings on bad URLs (just returns false).
 849  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 850  *    protocol-relative URLs) correctly.
 851  * 3) Adds a "delimiter" element to the array (see (2)).
 852  * 4) Verifies that the protocol is on the $wgUrlProtocols whitelist.
 853  * 5) Rejects some invalid URLs that parse_url doesn't, e.g. the empty string or URLs starting with
 854  *    a line feed character.
 855  *
 856  * @param string $url A URL to parse
 857  * @return string[]|bool Bits of the URL in an associative array, or false on failure.
 858  *   Possible fields:
 859  *   - scheme: URI scheme (protocol), e.g. 'http', 'mailto'. Lowercase, always present, but can
 860  *       be an empty string for protocol-relative URLs.
 861  *   - delimiter: either '://', ':' or '//'. Always present.
 862  *   - host: domain name / IP. Always present, but could be an empty string, e.g. for file: URLs.
 863  *   - user: user name, e.g. for HTTP Basic auth URLs such as http://user:pass@example.com/
 864  *       Missing when there is no username.
 865  *   - pass: password, same as above.
 866  *   - path: path including the leading /. Will be missing when empty (e.g. 'http://example.com')
 867  *   - query: query string (as a string; see wfCgiToArray() for parsing it), can be missing.
 868  *   - fragment: the part after #, can be missing.
 869  */
 870 function wfParseUrl( $url ) {
 871         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 872
 873         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 874         // bad that the easiest way to handle them is to just prepend 'http:' and
 875         // strip the protocol out later.
 876         $wasRelative = substr( $url, 0, 2 ) == '//';
 877         if ( $wasRelative ) {
 878                 $url = "http:$url";
 879         }
 880         Wikimedia\suppressWarnings();
 881         $bits = parse_url( $url );
 882         Wikimedia\restoreWarnings();
 883         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 884         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 885         if ( !$bits || !isset( $bits['scheme'] ) ) {
 886                 return false;
 887         }
 888
 889         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 890         $bits['scheme'] = strtolower( $bits['scheme'] );
 891
 892         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 893         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 894                 $bits['delimiter'] = '://';
 895         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 896                 $bits['delimiter'] = ':';
 897                 // parse_url detects for news: and mailto: the host part of an url as path
 898                 // We have to correct this wrong detection
 899                 if ( isset( $bits['path'] ) ) {
 900                         $bits['host'] = $bits['path'];
 901                         $bits['path'] = '';
 902                 }
 903         } else {
 904                 return false;
 905         }
 906
 907         /* Provide an empty host for eg. file:/// urls (see T30627) */
 908         if ( !isset( $bits['host'] ) ) {
 909                 $bits['host'] = '';
 910
 911                 // See T47069
 912                 if ( isset( $bits['path'] ) ) {
 913                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 914                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 915                                 $bits['path'] = '/' . $bits['path'];
 916                         }
 917                 } else {
 918                         $bits['path'] = '';
 919                 }
 920         }
 921
 922         // If the URL was protocol-relative, fix scheme and delimiter
 923         if ( $wasRelative ) {
 924                 $bits['scheme'] = '';
 925                 $bits['delimiter'] = '//';
 926         }
 927         return $bits;
 928 }
 929
 930 /**
 931  * Take a URL, make sure it's expanded to fully qualified, and replace any
 932  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 933  * for more compact display and legibility for local audiences.
 934  *
 935  * @todo handle punycode domains too
 936  *
 937  * @param string $url
 938  * @return string
 939  */
 940 function wfExpandIRI( $url ) {
 941         return preg_replace_callback(
 942                 '/((?:%[89A-F][0-9A-F])+)/i',
 943                 'wfExpandIRI_callback',
 944                 wfExpandUrl( $url )
 945         );
 946 }
 947
 948 /**
 949  * Private callback for wfExpandIRI
 950  * @param array $matches
 951  * @return string
 952  */
 953 function wfExpandIRI_callback( $matches ) {
 954         return urldecode( $matches[1] );
 955 }
 956
 957 /**
 958  * Make URL indexes, appropriate for the el_index field of externallinks.
 959  *
 960  * @param string $url
 961  * @return array
 962  */
 963 function wfMakeUrlIndexes( $url ) {
 964         $bits = wfParseUrl( $url );
 965
 966         // Reverse the labels in the hostname, convert to lower case
 967         // For emails reverse domainpart only
 968         if ( $bits['scheme'] == 'mailto' ) {
 969                 $mailparts = explode( '@', $bits['host'], 2 );
 970                 if ( count( $mailparts ) === 2 ) {
 971                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 972                 } else {
 973                         // No domain specified, don't mangle it
 974                         $domainpart = '';
 975                 }
 976                 $reversedHost = $domainpart . '@' . $mailparts[0];
 977         } else {
 978                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 979         }
 980         // Add an extra dot to the end
 981         // Why? Is it in wrong place in mailto links?
 982         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 983                 $reversedHost .= '.';
 984         }
 985         // Reconstruct the pseudo-URL
 986         $prot = $bits['scheme'];
 987         $index = $prot . $bits['delimiter'] . $reversedHost;
 988         // Leave out user and password. Add the port, path, query and fragment
 989         if ( isset( $bits['port'] ) ) {
 990                 $index .= ':' . $bits['port'];
 991         }
 992         if ( isset( $bits['path'] ) ) {
 993                 $index .= $bits['path'];
 994         } else {
 995                 $index .= '/';
 996         }
 997         if ( isset( $bits['query'] ) ) {
 998                 $index .= '?' . $bits['query'];
 999         }
1000         if ( isset( $bits['fragment'] ) ) {
1001                 $index .= '#' . $bits['fragment'];
1002         }
1003
1004         if ( $prot == '' ) {
1005                 return [ "http:$index", "https:$index" ];
1006         } else {
1007                 return [ $index ];
1008         }
1009 }
1010
1011 /**
1012  * Check whether a given URL has a domain that occurs in a given set of domains
1013  * @param string $url
1014  * @param array $domains Array of domains (strings)
1015  * @return bool True if the host part of $url ends in one of the strings in $domains
1016  */
1017 function wfMatchesDomainList( $url, $domains ) {
1018         $bits = wfParseUrl( $url );
1019         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1020                 $host = '.' . $bits['host'];
1021                 foreach ( (array)$domains as $domain ) {
1022                         $domain = '.' . $domain;
1023                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1024                                 return true;
1025                         }
1026                 }
1027         }
1028         return false;
1029 }
1030
1031 /**
1032  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1033  * In normal operation this is a NOP.
1034  *
1035  * Controlling globals:
1036  * $wgDebugLogFile - points to the log file
1037  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1038  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1039  *
1040  * @since 1.25 support for additional context data
1041  *
1042  * @param string $text
1043  * @param string|bool $dest Destination of the message:
1044  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1045  *     - 'private': excluded from HTML output
1046  *   For backward compatibility, it can also take a boolean:
1047  *     - true: same as 'all'
1048  *     - false: same as 'private'
1049  * @param array $context Additional logging context data
1050  */
1051 function wfDebug( $text, $dest = 'all', array $context = [] ) {
1052         global $wgDebugRawPage, $wgDebugLogPrefix;
1053         global $wgDebugTimestamps;
1054
1055         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1056                 return;
1057         }
1058
1059         $text = trim( $text );
1060
1061         if ( $wgDebugTimestamps ) {
1062                 $context['seconds_elapsed'] = sprintf(
1063                         '%6.4f',
1064                         microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT']
1065                 );
1066                 $context['memory_used'] = sprintf(
1067                         '%5.1fM',
1068                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1069                 );
1070         }
1071
1072         if ( $wgDebugLogPrefix !== '' ) {
1073                 $context['prefix'] = $wgDebugLogPrefix;
1074         }
1075         $context['private'] = ( $dest === false || $dest === 'private' );
1076
1077         $logger = LoggerFactory::getInstance( 'wfDebug' );
1078         $logger->debug( $text, $context );
1079 }
1080
1081 /**
1082  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1083  * @return bool
1084  */
1085 function wfIsDebugRawPage() {
1086         static $cache;
1087         if ( $cache !== null ) {
1088                 return $cache;
1089         }
1090         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1091         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1092                 || (
1093                         isset( $_SERVER['SCRIPT_NAME'] )
1094                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1095                 )
1096         ) {
1097                 $cache = true;
1098         } else {
1099                 $cache = false;
1100         }
1101         return $cache;
1102 }
1103
1104 /**
1105  * Send a line giving PHP memory usage.
1106  *
1107  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1108  */
1109 function wfDebugMem( $exact = false ) {
1110         $mem = memory_get_usage();
1111         if ( !$exact ) {
1112                 $mem = floor( $mem / 1024 ) . ' KiB';
1113         } else {
1114                 $mem .= ' B';
1115         }
1116         wfDebug( "Memory usage: $mem\n" );
1117 }
1118
1119 /**
1120  * Send a line to a supplementary debug log file, if configured, or main debug
1121  * log if not.
1122  *
1123  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1124  * a string filename or an associative array mapping 'destination' to the
1125  * desired filename. The associative array may also contain a 'sample' key
1126  * with an integer value, specifying a sampling factor. Sampled log events
1127  * will be emitted with a 1 in N random chance.
1128  *
1129  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1130  * @since 1.25 support for additional context data
1131  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1132  *
1133  * @param string $logGroup
1134  * @param string $text
1135  * @param string|bool $dest Destination of the message:
1136  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1137  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1138  *       discarded otherwise
1139  *   For backward compatibility, it can also take a boolean:
1140  *     - true: same as 'all'
1141  *     - false: same as 'private'
1142  * @param array $context Additional logging context data
1143  */
1144 function wfDebugLog(
1145         $logGroup, $text, $dest = 'all', array $context = []
1146 ) {
1147         $text = trim( $text );
1148
1149         $logger = LoggerFactory::getInstance( $logGroup );
1150         $context['private'] = ( $dest === false || $dest === 'private' );
1151         $logger->info( $text, $context );
1152 }
1153
1154 /**
1155  * Log for database errors
1156  *
1157  * @since 1.25 support for additional context data
1158  *
1159  * @param string $text Database error message.
1160  * @param array $context Additional logging context data
1161  */
1162 function wfLogDBError( $text, array $context = [] ) {
1163         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1164         $logger->error( trim( $text ), $context );
1165 }
1166
1167 /**
1168  * Throws a warning that $function is deprecated
1169  *
1170  * @param string $function
1171  * @param string|bool $version Version of MediaWiki that the function
1172  *    was deprecated in (Added in 1.19).
1173  * @param string|bool $component Added in 1.19.
1174  * @param int $callerOffset How far up the call stack is the original
1175  *    caller. 2 = function that called the function that called
1176  *    wfDeprecated (Added in 1.20)
1177  *
1178  * @return null
1179  */
1180 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1181         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1182 }
1183
1184 /**
1185  * Send a warning either to the debug log or in a PHP error depending on
1186  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1187  *
1188  * @param string $msg Message to send
1189  * @param int $callerOffset Number of items to go back in the backtrace to
1190  *        find the correct caller (1 = function calling wfWarn, ...)
1191  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1192  *        only used when $wgDevelopmentWarnings is true
1193  */
1194 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1195         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1196 }
1197
1198 /**
1199  * Send a warning as a PHP error and the debug log. This is intended for logging
1200  * warnings in production. For logging development warnings, use WfWarn instead.
1201  *
1202  * @param string $msg Message to send
1203  * @param int $callerOffset Number of items to go back in the backtrace to
1204  *        find the correct caller (1 = function calling wfLogWarning, ...)
1205  * @param int $level PHP error level; defaults to E_USER_WARNING
1206  */
1207 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1208         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1209 }
1210
1211 /**
1212  * Log to a file without getting "file size exceeded" signals.
1213  *
1214  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1215  * send lines to the specified port, prefixed by the specified prefix and a space.
1216  * @since 1.25 support for additional context data
1217  *
1218  * @param string $text
1219  * @param string $file Filename
1220  * @param array $context Additional logging context data
1221  * @throws MWException
1222  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1223  */
1224 function wfErrorLog( $text, $file, array $context = [] ) {
1225         wfDeprecated( __METHOD__, '1.25' );
1226         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1227         $context['destination'] = $file;
1228         $logger->info( trim( $text ), $context );
1229 }
1230
1231 /**
1232  * @todo document
1233  * @todo Move logic to MediaWiki.php
1234  */
1235 function wfLogProfilingData() {
1236         global $wgDebugLogGroups, $wgDebugRawPage;
1237
1238         $context = RequestContext::getMain();
1239         $request = $context->getRequest();
1240
1241         $profiler = Profiler::instance();
1242         $profiler->setContext( $context );
1243         $profiler->logData();
1244
1245         // Send out any buffered statsd metrics as needed
1246         MediaWiki::emitBufferedStatsdData(
1247                 MediaWikiServices::getInstance()->getStatsdDataFactory(),
1248                 $context->getConfig()
1249         );
1250
1251         // Profiling must actually be enabled...
1252         if ( $profiler instanceof ProfilerStub ) {
1253                 return;
1254         }
1255
1256         if ( isset( $wgDebugLogGroups['profileoutput'] )
1257                 && $wgDebugLogGroups['profileoutput'] === false
1258         ) {
1259                 // Explicitly disabled
1260                 return;
1261         }
1262         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1263                 return;
1264         }
1265
1266         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1267         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1268                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1269         }
1270         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1271                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1272         }
1273         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1274                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1275         }
1276         if ( isset( $ctx['forwarded_for'] ) ||
1277                 isset( $ctx['client_ip'] ) ||
1278                 isset( $ctx['from'] ) ) {
1279                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1280         }
1281
1282         // Don't load $wgUser at this late stage just for statistics purposes
1283         // @todo FIXME: We can detect some anons even if it is not loaded.
1284         // See User::getId()
1285         $user = $context->getUser();
1286         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1287
1288         // Command line script uses a FauxRequest object which does not have
1289         // any knowledge about an URL and throw an exception instead.
1290         try {
1291                 $ctx['url'] = urldecode( $request->getRequestURL() );
1292         } catch ( Exception $ignored ) {
1293                 // no-op
1294         }
1295
1296         $ctx['output'] = $profiler->getOutput();
1297
1298         $log = LoggerFactory::getInstance( 'profileoutput' );
1299         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1300 }
1301
1302 /**
1303  * Increment a statistics counter
1304  *
1305  * @param string $key
1306  * @param int $count
1307  * @return void
1308  */
1309 function wfIncrStats( $key, $count = 1 ) {
1310         $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1311         $stats->updateCount( $key, $count );
1312 }
1313
1314 /**
1315  * Check whether the wiki is in read-only mode.
1316  *
1317  * @return bool
1318  */
1319 function wfReadOnly() {
1320         return MediaWikiServices::getInstance()->getReadOnlyMode()
1321                 ->isReadOnly();
1322 }
1323
1324 /**
1325  * Check if the site is in read-only mode and return the message if so
1326  *
1327  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1328  * for replica DB lag. This may result in DB connection being made.
1329  *
1330  * @return string|bool String when in read-only mode; false otherwise
1331  */
1332 function wfReadOnlyReason() {
1333         return MediaWikiServices::getInstance()->getReadOnlyMode()
1334                 ->getReason();
1335 }
1336
1337 /**
1338  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1339  *
1340  * @return string|bool String when in read-only mode; false otherwise
1341  * @since 1.27
1342  */
1343 function wfConfiguredReadOnlyReason() {
1344         return MediaWikiServices::getInstance()->getConfiguredReadOnlyMode()
1345                 ->getReason();
1346 }
1347
1348 /**
1349  * Return a Language object from $langcode
1350  *
1351  * @param Language|string|bool $langcode Either:
1352  *                  - a Language object
1353  *                  - code of the language to get the message for, if it is
1354  *                    a valid code create a language for that language, if
1355  *                    it is a string but not a valid code then make a basic
1356  *                    language object
1357  *                  - a boolean: if it's false then use the global object for
1358  *                    the current user's language (as a fallback for the old parameter
1359  *                    functionality), or if it is true then use global object
1360  *                    for the wiki's content language.
1361  * @return Language
1362  */
1363 function wfGetLangObj( $langcode = false ) {
1364         # Identify which language to get or create a language object for.
1365         # Using is_object here due to Stub objects.
1366         if ( is_object( $langcode ) ) {
1367                 # Great, we already have the object (hopefully)!
1368                 return $langcode;
1369         }
1370
1371         global $wgContLang, $wgLanguageCode;
1372         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1373                 # $langcode is the language code of the wikis content language object.
1374                 # or it is a boolean and value is true
1375                 return $wgContLang;
1376         }
1377
1378         global $wgLang;
1379         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1380                 # $langcode is the language code of user language object.
1381                 # or it was a boolean and value is false
1382                 return $wgLang;
1383         }
1384
1385         $validCodes = array_keys( Language::fetchLanguageNames() );
1386         if ( in_array( $langcode, $validCodes ) ) {
1387                 # $langcode corresponds to a valid language.
1388                 return Language::factory( $langcode );
1389         }
1390
1391         # $langcode is a string, but not a valid language code; use content language.
1392         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1393         return $wgContLang;
1394 }
1395
1396 /**
1397  * This is the function for getting translated interface messages.
1398  *
1399  * @see Message class for documentation how to use them.
1400  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1401  *
1402  * This function replaces all old wfMsg* functions.
1403  *
1404  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1405  * @param mixed $params,... Normal message parameters
1406  * @return Message
1407  *
1408  * @since 1.17
1409  *
1410  * @see Message::__construct
1411  */
1412 function wfMessage( $key /*...*/ ) {
1413         $message = new Message( $key );
1414
1415         // We call Message::params() to reduce code duplication
1416         $params = func_get_args();
1417         array_shift( $params );
1418         if ( $params ) {
1419                 call_user_func_array( [ $message, 'params' ], $params );
1420         }
1421
1422         return $message;
1423 }
1424
1425 /**
1426  * This function accepts multiple message keys and returns a message instance
1427  * for the first message which is non-empty. If all messages are empty then an
1428  * instance of the first message key is returned.
1429  *
1430  * @param string|string[] $keys,... Message keys
1431  * @return Message
1432  *
1433  * @since 1.18
1434  *
1435  * @see Message::newFallbackSequence
1436  */
1437 function wfMessageFallback( /*...*/ ) {
1438         $args = func_get_args();
1439         return call_user_func_array( 'Message::newFallbackSequence', $args );
1440 }
1441
1442 /**
1443  * Replace message parameter keys on the given formatted output.
1444  *
1445  * @param string $message
1446  * @param array $args
1447  * @return string
1448  * @private
1449  */
1450 function wfMsgReplaceArgs( $message, $args ) {
1451         # Fix windows line-endings
1452         # Some messages are split with explode("\n", $msg)
1453         $message = str_replace( "\r", '', $message );
1454
1455         // Replace arguments
1456         if ( is_array( $args ) && $args ) {
1457                 if ( is_array( $args[0] ) ) {
1458                         $args = array_values( $args[0] );
1459                 }
1460                 $replacementKeys = [];
1461                 foreach ( $args as $n => $param ) {
1462                         $replacementKeys['$' . ( $n + 1 )] = $param;
1463                 }
1464                 $message = strtr( $message, $replacementKeys );
1465         }
1466
1467         return $message;
1468 }
1469
1470 /**
1471  * Fetch server name for use in error reporting etc.
1472  * Use real server name if available, so we know which machine
1473  * in a server farm generated the current page.
1474  *
1475  * @return string
1476  */
1477 function wfHostname() {
1478         static $host;
1479         if ( is_null( $host ) ) {
1480                 # Hostname overriding
1481                 global $wgOverrideHostname;
1482                 if ( $wgOverrideHostname !== false ) {
1483                         # Set static and skip any detection
1484                         $host = $wgOverrideHostname;
1485                         return $host;
1486                 }
1487
1488                 if ( function_exists( 'posix_uname' ) ) {
1489                         // This function not present on Windows
1490                         $uname = posix_uname();
1491                 } else {
1492                         $uname = false;
1493                 }
1494                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1495                         $host = $uname['nodename'];
1496                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1497                         # Windows computer name
1498                         $host = getenv( 'COMPUTERNAME' );
1499                 } else {
1500                         # This may be a virtual server.
1501                         $host = $_SERVER['SERVER_NAME'];
1502                 }
1503         }
1504         return $host;
1505 }
1506
1507 /**
1508  * Returns a script tag that stores the amount of time it took MediaWiki to
1509  * handle the request in milliseconds as 'wgBackendResponseTime'.
1510  *
1511  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1512  * hostname of the server handling the request.
1513  *
1514  * @return string
1515  */
1516 function wfReportTime() {
1517         global $wgShowHostnames;
1518
1519         $elapsed = ( microtime( true ) - $_SERVER['REQUEST_TIME_FLOAT'] );
1520         // seconds to milliseconds
1521         $responseTime = round( $elapsed * 1000 );
1522         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1523         if ( $wgShowHostnames ) {
1524                 $reportVars['wgHostname'] = wfHostname();
1525         }
1526         return Skin::makeVariablesScript( $reportVars );
1527 }
1528
1529 /**
1530  * Safety wrapper for debug_backtrace().
1531  *
1532  * Will return an empty array if debug_backtrace is disabled, otherwise
1533  * the output from debug_backtrace() (trimmed).
1534  *
1535  * @param int $limit This parameter can be used to limit the number of stack frames returned
1536  *
1537  * @return array Array of backtrace information
1538  */
1539 function wfDebugBacktrace( $limit = 0 ) {
1540         static $disabled = null;
1541
1542         if ( is_null( $disabled ) ) {
1543                 $disabled = !function_exists( 'debug_backtrace' );
1544                 if ( $disabled ) {
1545                         wfDebug( "debug_backtrace() is disabled\n" );
1546                 }
1547         }
1548         if ( $disabled ) {
1549                 return [];
1550         }
1551
1552         if ( $limit ) {
1553                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1554         } else {
1555                 return array_slice( debug_backtrace(), 1 );
1556         }
1557 }
1558
1559 /**
1560  * Get a debug backtrace as a string
1561  *
1562  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1563  *   Defaults to $wgCommandLineMode if unset.
1564  * @return string
1565  * @since 1.25 Supports $raw parameter.
1566  */
1567 function wfBacktrace( $raw = null ) {
1568         global $wgCommandLineMode;
1569
1570         if ( $raw === null ) {
1571                 $raw = $wgCommandLineMode;
1572         }
1573
1574         if ( $raw ) {
1575                 $frameFormat = "%s line %s calls %s()\n";
1576                 $traceFormat = "%s";
1577         } else {
1578                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1579                 $traceFormat = "<ul>\n%s</ul>\n";
1580         }
1581
1582         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1583                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1584                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1585                 $call = $frame['function'];
1586                 if ( !empty( $frame['class'] ) ) {
1587                         $call = $frame['class'] . $frame['type'] . $call;
1588                 }
1589                 return sprintf( $frameFormat, $file, $line, $call );
1590         }, wfDebugBacktrace() );
1591
1592         return sprintf( $traceFormat, implode( '', $frames ) );
1593 }
1594
1595 /**
1596  * Get the name of the function which called this function
1597  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1598  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1599  * wfGetCaller( 3 ) is the parent of that.
1600  *
1601  * @param int $level
1602  * @return string
1603  */
1604 function wfGetCaller( $level = 2 ) {
1605         $backtrace = wfDebugBacktrace( $level + 1 );
1606         if ( isset( $backtrace[$level] ) ) {
1607                 return wfFormatStackFrame( $backtrace[$level] );
1608         } else {
1609                 return 'unknown';
1610         }
1611 }
1612
1613 /**
1614  * Return a string consisting of callers in the stack. Useful sometimes
1615  * for profiling specific points.
1616  *
1617  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1618  * @return string
1619  */
1620 function wfGetAllCallers( $limit = 3 ) {
1621         $trace = array_reverse( wfDebugBacktrace() );
1622         if ( !$limit || $limit > count( $trace ) - 1 ) {
1623                 $limit = count( $trace ) - 1;
1624         }
1625         $trace = array_slice( $trace, -$limit - 1, $limit );
1626         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1627 }
1628
1629 /**
1630  * Return a string representation of frame
1631  *
1632  * @param array $frame
1633  * @return string
1634  */
1635 function wfFormatStackFrame( $frame ) {
1636         if ( !isset( $frame['function'] ) ) {
1637                 return 'NO_FUNCTION_GIVEN';
1638         }
1639         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1640                 $frame['class'] . $frame['type'] . $frame['function'] :
1641                 $frame['function'];
1642 }
1643
1644 /* Some generic result counters, pulled out of SearchEngine */
1645
1646 /**
1647  * @todo document
1648  *
1649  * @param int $offset
1650  * @param int $limit
1651  * @return string
1652  */
1653 function wfShowingResults( $offset, $limit ) {
1654         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1655 }
1656
1657 /**
1658  * Whether the client accept gzip encoding
1659  *
1660  * Uses the Accept-Encoding header to check if the client supports gzip encoding.
1661  * Use this when considering to send a gzip-encoded response to the client.
1662  *
1663  * @param bool $force Forces another check even if we already have a cached result.
1664  * @return bool
1665  */
1666 function wfClientAcceptsGzip( $force = false ) {
1667         static $result = null;
1668         if ( $result === null || $force ) {
1669                 $result = false;
1670                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1671                         # @todo FIXME: We may want to blacklist some broken browsers
1672                         $m = [];
1673                         if ( preg_match(
1674                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1675                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1676                                         $m
1677                                 )
1678                         ) {
1679                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1680                                         $result = false;
1681                                         return $result;
1682                                 }
1683                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1684                                 $result = true;
1685                         }
1686                 }
1687         }
1688         return $result;
1689 }
1690
1691 /**
1692  * Escapes the given text so that it may be output using addWikiText()
1693  * without any linking, formatting, etc. making its way through. This
1694  * is achieved by substituting certain characters with HTML entities.
1695  * As required by the callers, "<nowiki>" is not used.
1696  *
1697  * @param string $text Text to be escaped
1698  * @return string
1699  */
1700 function wfEscapeWikiText( $text ) {
1701         global $wgEnableMagicLinks;
1702         static $repl = null, $repl2 = null;
1703         if ( $repl === null || defined( 'MW_PARSER_TEST' ) || defined( 'MW_PHPUNIT_TEST' ) ) {
1704                 // Tests depend upon being able to change $wgEnableMagicLinks, so don't cache
1705                 // in those situations
1706                 $repl = [
1707                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1708                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1709                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1710                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1711                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1712                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1713                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1714                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1715                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1716                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1717                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1718                         '__' => '_&#95;', '://' => '&#58;//',
1719                 ];
1720
1721                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1722                 // We have to catch everything "\s" matches in PCRE
1723                 foreach ( $magicLinks as $magic ) {
1724                         $repl["$magic "] = "$magic&#32;";
1725                         $repl["$magic\t"] = "$magic&#9;";
1726                         $repl["$magic\r"] = "$magic&#13;";
1727                         $repl["$magic\n"] = "$magic&#10;";
1728                         $repl["$magic\f"] = "$magic&#12;";
1729                 }
1730
1731                 // And handle protocols that don't use "://"
1732                 global $wgUrlProtocols;
1733                 $repl2 = [];
1734                 foreach ( $wgUrlProtocols as $prot ) {
1735                         if ( substr( $prot, -1 ) === ':' ) {
1736                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1737                         }
1738                 }
1739                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1740         }
1741         $text = substr( strtr( "\n$text", $repl ), 1 );
1742         $text = preg_replace( $repl2, '$1&#58;', $text );
1743         return $text;
1744 }
1745
1746 /**
1747  * Sets dest to source and returns the original value of dest
1748  * If source is NULL, it just returns the value, it doesn't set the variable
1749  * If force is true, it will set the value even if source is NULL
1750  *
1751  * @param mixed &$dest
1752  * @param mixed $source
1753  * @param bool $force
1754  * @return mixed
1755  */
1756 function wfSetVar( &$dest, $source, $force = false ) {
1757         $temp = $dest;
1758         if ( !is_null( $source ) || $force ) {
1759                 $dest = $source;
1760         }
1761         return $temp;
1762 }
1763
1764 /**
1765  * As for wfSetVar except setting a bit
1766  *
1767  * @param int &$dest
1768  * @param int $bit
1769  * @param bool $state
1770  *
1771  * @return bool
1772  */
1773 function wfSetBit( &$dest, $bit, $state = true ) {
1774         $temp = (bool)( $dest & $bit );
1775         if ( !is_null( $state ) ) {
1776                 if ( $state ) {
1777                         $dest |= $bit;
1778                 } else {
1779                         $dest &= ~$bit;
1780                 }
1781         }
1782         return $temp;
1783 }
1784
1785 /**
1786  * A wrapper around the PHP function var_export().
1787  * Either print it or add it to the regular output ($wgOut).
1788  *
1789  * @param mixed $var A PHP variable to dump.
1790  */
1791 function wfVarDump( $var ) {
1792         global $wgOut;
1793         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1794         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1795                 print $s;
1796         } else {
1797                 $wgOut->addHTML( $s );
1798         }
1799 }
1800
1801 /**
1802  * Provide a simple HTTP error.
1803  *
1804  * @param int|string $code
1805  * @param string $label
1806  * @param string $desc
1807  */
1808 function wfHttpError( $code, $label, $desc ) {
1809         global $wgOut;
1810         HttpStatus::header( $code );
1811         if ( $wgOut ) {
1812                 $wgOut->disable();
1813                 $wgOut->sendCacheControl();
1814         }
1815
1816         MediaWiki\HeaderCallback::warnIfHeadersSent();
1817         header( 'Content-type: text/html; charset=utf-8' );
1818         print '<!DOCTYPE html>' .
1819                 '<html><head><title>' .
1820                 htmlspecialchars( $label ) .
1821                 '</title></head><body><h1>' .
1822                 htmlspecialchars( $label ) .
1823                 '</h1><p>' .
1824                 nl2br( htmlspecialchars( $desc ) ) .
1825                 "</p></body></html>\n";
1826 }
1827
1828 /**
1829  * Clear away any user-level output buffers, discarding contents.
1830  *
1831  * Suitable for 'starting afresh', for instance when streaming
1832  * relatively large amounts of data without buffering, or wanting to
1833  * output image files without ob_gzhandler's compression.
1834  *
1835  * The optional $resetGzipEncoding parameter controls suppression of
1836  * the Content-Encoding header sent by ob_gzhandler; by default it
1837  * is left. See comments for wfClearOutputBuffers() for why it would
1838  * be used.
1839  *
1840  * Note that some PHP configuration options may add output buffer
1841  * layers which cannot be removed; these are left in place.
1842  *
1843  * @param bool $resetGzipEncoding
1844  */
1845 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1846         if ( $resetGzipEncoding ) {
1847                 // Suppress Content-Encoding and Content-Length
1848                 // headers from OutputHandler::handle.
1849                 global $wgDisableOutputCompression;
1850                 $wgDisableOutputCompression = true;
1851         }
1852         while ( $status = ob_get_status() ) {
1853                 if ( isset( $status['flags'] ) ) {
1854                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1855                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1856                 } elseif ( isset( $status['del'] ) ) {
1857                         $deleteable = $status['del'];
1858                 } else {
1859                         // Guess that any PHP-internal setting can't be removed.
1860                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1861                 }
1862                 if ( !$deleteable ) {
1863                         // Give up, and hope the result doesn't break
1864                         // output behavior.
1865                         break;
1866                 }
1867                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1868                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1869                         break;
1870                 }
1871                 if ( !ob_end_clean() ) {
1872                         // Could not remove output buffer handler; abort now
1873                         // to avoid getting in some kind of infinite loop.
1874                         break;
1875                 }
1876                 if ( $resetGzipEncoding ) {
1877                         if ( $status['name'] == 'ob_gzhandler' ) {
1878                                 // Reset the 'Content-Encoding' field set by this handler
1879                                 // so we can start fresh.
1880                                 header_remove( 'Content-Encoding' );
1881                                 break;
1882                         }
1883                 }
1884         }
1885 }
1886
1887 /**
1888  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1889  *
1890  * Clear away output buffers, but keep the Content-Encoding header
1891  * produced by ob_gzhandler, if any.
1892  *
1893  * This should be used for HTTP 304 responses, where you need to
1894  * preserve the Content-Encoding header of the real result, but
1895  * also need to suppress the output of ob_gzhandler to keep to spec
1896  * and avoid breaking Firefox in rare cases where the headers and
1897  * body are broken over two packets.
1898  */
1899 function wfClearOutputBuffers() {
1900         wfResetOutputBuffers( false );
1901 }
1902
1903 /**
1904  * Converts an Accept-* header into an array mapping string values to quality
1905  * factors
1906  *
1907  * @param string $accept
1908  * @param string $def Default
1909  * @return float[] Associative array of string => float pairs
1910  */
1911 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1912         # No arg means accept anything (per HTTP spec)
1913         if ( !$accept ) {
1914                 return [ $def => 1.0 ];
1915         }
1916
1917         $prefs = [];
1918
1919         $parts = explode( ',', $accept );
1920
1921         foreach ( $parts as $part ) {
1922                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1923                 $values = explode( ';', trim( $part ) );
1924                 $match = [];
1925                 if ( count( $values ) == 1 ) {
1926                         $prefs[$values[0]] = 1.0;
1927                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1928                         $prefs[$values[0]] = floatval( $match[1] );
1929                 }
1930         }
1931
1932         return $prefs;
1933 }
1934
1935 /**
1936  * Checks if a given MIME type matches any of the keys in the given
1937  * array. Basic wildcards are accepted in the array keys.
1938  *
1939  * Returns the matching MIME type (or wildcard) if a match, otherwise
1940  * NULL if no match.
1941  *
1942  * @param string $type
1943  * @param array $avail
1944  * @return string
1945  * @private
1946  */
1947 function mimeTypeMatch( $type, $avail ) {
1948         if ( array_key_exists( $type, $avail ) ) {
1949                 return $type;
1950         } else {
1951                 $mainType = explode( '/', $type )[0];
1952                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1953                         return "$mainType/*";
1954                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1955                         return '*/*';
1956                 } else {
1957                         return null;
1958                 }
1959         }
1960 }
1961
1962 /**
1963  * Returns the 'best' match between a client's requested internet media types
1964  * and the server's list of available types. Each list should be an associative
1965  * array of type to preference (preference is a float between 0.0 and 1.0).
1966  * Wildcards in the types are acceptable.
1967  *
1968  * @param array $cprefs Client's acceptable type list
1969  * @param array $sprefs Server's offered types
1970  * @return string
1971  *
1972  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1973  * XXX: generalize to negotiate other stuff
1974  */
1975 function wfNegotiateType( $cprefs, $sprefs ) {
1976         $combine = [];
1977
1978         foreach ( array_keys( $sprefs ) as $type ) {
1979                 $subType = explode( '/', $type )[1];
1980                 if ( $subType != '*' ) {
1981                         $ckey = mimeTypeMatch( $type, $cprefs );
1982                         if ( $ckey ) {
1983                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1984                         }
1985                 }
1986         }
1987
1988         foreach ( array_keys( $cprefs ) as $type ) {
1989                 $subType = explode( '/', $type )[1];
1990                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1991                         $skey = mimeTypeMatch( $type, $sprefs );
1992                         if ( $skey ) {
1993                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1994                         }
1995                 }
1996         }
1997
1998         $bestq = 0;
1999         $besttype = null;
2000
2001         foreach ( array_keys( $combine ) as $type ) {
2002                 if ( $combine[$type] > $bestq ) {
2003                         $besttype = $type;
2004                         $bestq = $combine[$type];
2005                 }
2006         }
2007
2008         return $besttype;
2009 }
2010
2011 /**
2012  * Reference-counted warning suppression
2013  *
2014  * @deprecated since 1.26, use Wikimedia\suppressWarnings() directly
2015  * @param bool $end
2016  */
2017 function wfSuppressWarnings( $end = false ) {
2018         Wikimedia\suppressWarnings( $end );
2019 }
2020
2021 /**
2022  * @deprecated since 1.26, use Wikimedia\restoreWarnings() directly
2023  * Restore error level to previous value
2024  */
2025 function wfRestoreWarnings() {
2026         Wikimedia\restoreWarnings();
2027 }
2028
2029 /**
2030  * Get a timestamp string in one of various formats
2031  *
2032  * @param mixed $outputtype A timestamp in one of the supported formats, the
2033  *   function will autodetect which format is supplied and act accordingly.
2034  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2035  * @return string|bool String / false The same date in the format specified in $outputtype or false
2036  */
2037 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2038         $ret = MWTimestamp::convert( $outputtype, $ts );
2039         if ( $ret === false ) {
2040                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2041         }
2042         return $ret;
2043 }
2044
2045 /**
2046  * Return a formatted timestamp, or null if input is null.
2047  * For dealing with nullable timestamp columns in the database.
2048  *
2049  * @param int $outputtype
2050  * @param string $ts
2051  * @return string
2052  */
2053 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2054         if ( is_null( $ts ) ) {
2055                 return null;
2056         } else {
2057                 return wfTimestamp( $outputtype, $ts );
2058         }
2059 }
2060
2061 /**
2062  * Convenience function; returns MediaWiki timestamp for the present time.
2063  *
2064  * @return string
2065  */
2066 function wfTimestampNow() {
2067         # return NOW
2068         return MWTimestamp::now( TS_MW );
2069 }
2070
2071 /**
2072  * Check if the operating system is Windows
2073  *
2074  * @return bool True if it's Windows, false otherwise.
2075  */
2076 function wfIsWindows() {
2077         static $isWindows = null;
2078         if ( $isWindows === null ) {
2079                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2080         }
2081         return $isWindows;
2082 }
2083
2084 /**
2085  * Check if we are running under HHVM
2086  *
2087  * @return bool
2088  */
2089 function wfIsHHVM() {
2090         return defined( 'HHVM_VERSION' );
2091 }
2092
2093 /**
2094  * Check if we are running from the commandline
2095  *
2096  * @since 1.31
2097  * @return bool
2098  */
2099 function wfIsCLI() {
2100         return PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg';
2101 }
2102
2103 /**
2104  * Tries to get the system directory for temporary files. First
2105  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2106  * environment variables are then checked in sequence, then
2107  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2108  *
2109  * NOTE: When possible, use instead the tmpfile() function to create
2110  * temporary files to avoid race conditions on file creation, etc.
2111  *
2112  * @return string
2113  */
2114 function wfTempDir() {
2115         global $wgTmpDirectory;
2116
2117         if ( $wgTmpDirectory !== false ) {
2118                 return $wgTmpDirectory;
2119         }
2120
2121         return TempFSFile::getUsableTempDirectory();
2122 }
2123
2124 /**
2125  * Make directory, and make all parent directories if they don't exist
2126  *
2127  * @param string $dir Full path to directory to create
2128  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2129  * @param string $caller Optional caller param for debugging.
2130  * @throws MWException
2131  * @return bool
2132  */
2133 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2134         global $wgDirectoryMode;
2135
2136         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2137                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2138         }
2139
2140         if ( !is_null( $caller ) ) {
2141                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2142         }
2143
2144         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2145                 return true;
2146         }
2147
2148         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
2149
2150         if ( is_null( $mode ) ) {
2151                 $mode = $wgDirectoryMode;
2152         }
2153
2154         // Turn off the normal warning, we're doing our own below
2155         Wikimedia\suppressWarnings();
2156         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2157         Wikimedia\restoreWarnings();
2158
2159         if ( !$ok ) {
2160                 // directory may have been created on another request since we last checked
2161                 if ( is_dir( $dir ) ) {
2162                         return true;
2163                 }
2164
2165                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2166                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2167         }
2168         return $ok;
2169 }
2170
2171 /**
2172  * Remove a directory and all its content.
2173  * Does not hide error.
2174  * @param string $dir
2175  */
2176 function wfRecursiveRemoveDir( $dir ) {
2177         wfDebug( __FUNCTION__ . "( $dir )\n" );
2178         // taken from https://secure.php.net/manual/en/function.rmdir.php#98622
2179         if ( is_dir( $dir ) ) {
2180                 $objects = scandir( $dir );
2181                 foreach ( $objects as $object ) {
2182                         if ( $object != "." && $object != ".." ) {
2183                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2184                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2185                                 } else {
2186                                         unlink( $dir . '/' . $object );
2187                                 }
2188                         }
2189                 }
2190                 reset( $objects );
2191                 rmdir( $dir );
2192         }
2193 }
2194
2195 /**
2196  * @param int $nr The number to format
2197  * @param int $acc The number of digits after the decimal point, default 2
2198  * @param bool $round Whether or not to round the value, default true
2199  * @return string
2200  */
2201 function wfPercent( $nr, $acc = 2, $round = true ) {
2202         $ret = sprintf( "%.${acc}f", $nr );
2203         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2204 }
2205
2206 /**
2207  * Safety wrapper around ini_get() for boolean settings.
2208  * The values returned from ini_get() are pre-normalized for settings
2209  * set via php.ini or php_flag/php_admin_flag... but *not*
2210  * for those set via php_value/php_admin_value.
2211  *
2212  * It's fairly common for people to use php_value instead of php_flag,
2213  * which can leave you with an 'off' setting giving a false positive
2214  * for code that just takes the ini_get() return value as a boolean.
2215  *
2216  * To make things extra interesting, setting via php_value accepts
2217  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2218  * Unrecognized values go false... again opposite PHP's own coercion
2219  * from string to bool.
2220  *
2221  * Luckily, 'properly' set settings will always come back as '0' or '1',
2222  * so we only have to worry about them and the 'improper' settings.
2223  *
2224  * I frickin' hate PHP... :P
2225  *
2226  * @param string $setting
2227  * @return bool
2228  */
2229 function wfIniGetBool( $setting ) {
2230         return wfStringToBool( ini_get( $setting ) );
2231 }
2232
2233 /**
2234  * Convert string value to boolean, when the following are interpreted as true:
2235  * - on
2236  * - true
2237  * - yes
2238  * - Any number, except 0
2239  * All other strings are interpreted as false.
2240  *
2241  * @param string $val
2242  * @return bool
2243  * @since 1.31
2244  */
2245 function wfStringToBool( $val ) {
2246         $val = strtolower( $val );
2247         // 'on' and 'true' can't have whitespace around them, but '1' can.
2248         return $val == 'on'
2249                 || $val == 'true'
2250                 || $val == 'yes'
2251                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2252 }
2253
2254 /**
2255  * Version of escapeshellarg() that works better on Windows.
2256  *
2257  * Originally, this fixed the incorrect use of single quotes on Windows
2258  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2259  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2260  *
2261  * @param string $args,... strings to escape and glue together,
2262  *  or a single array of strings parameter
2263  * @return string
2264  * @deprecated since 1.30 use MediaWiki\Shell::escape()
2265  */
2266 function wfEscapeShellArg( /*...*/ ) {
2267         $args = func_get_args();
2268
2269         return call_user_func_array( Shell::class . '::escape', $args );
2270 }
2271
2272 /**
2273  * Check if wfShellExec() is effectively disabled via php.ini config
2274  *
2275  * @return bool|string False or 'disabled'
2276  * @since 1.22
2277  * @deprecated since 1.30 use MediaWiki\Shell::isDisabled()
2278  */
2279 function wfShellExecDisabled() {
2280         wfDeprecated( __FUNCTION__, '1.30' );
2281         return Shell::isDisabled() ? 'disabled' : false;
2282 }
2283
2284 /**
2285  * Execute a shell command, with time and memory limits mirrored from the PHP
2286  * configuration if supported.
2287  *
2288  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2289  *   or an array of unescaped arguments, in which case each value will be escaped
2290  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2291  * @param null|mixed &$retval Optional, will receive the program's exit code.
2292  *   (non-zero is usually failure). If there is an error from
2293  *   read, select, or proc_open(), this will be set to -1.
2294  * @param array $environ Optional environment variables which should be
2295  *   added to the executed command environment.
2296  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2297  *   this overwrites the global wgMaxShell* limits.
2298  * @param array $options Array of options:
2299  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2300  *     including errors from limit.sh
2301  *   - profileMethod: By default this function will profile based on the calling
2302  *     method. Set this to a string for an alternative method to profile from
2303  *
2304  * @return string Collected stdout as a string
2305  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2306  */
2307 function wfShellExec( $cmd, &$retval = null, $environ = [],
2308         $limits = [], $options = []
2309 ) {
2310         if ( Shell::isDisabled() ) {
2311                 $retval = 1;
2312                 // Backwards compatibility be upon us...
2313                 return 'Unable to run external programs, proc_open() is disabled.';
2314         }
2315
2316         if ( is_array( $cmd ) ) {
2317                 $cmd = Shell::escape( $cmd );
2318         }
2319
2320         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2321         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2322
2323         try {
2324                 $result = Shell::command( [] )
2325                         ->unsafeParams( (array)$cmd )
2326                         ->environment( $environ )
2327                         ->limits( $limits )
2328                         ->includeStderr( $includeStderr )
2329                         ->profileMethod( $profileMethod )
2330                         ->execute();
2331         } catch ( ProcOpenError $ex ) {
2332                 $retval = -1;
2333                 return '';
2334         }
2335
2336         $retval = $result->getExitCode();
2337
2338         return $result->getStdout();
2339 }
2340
2341 /**
2342  * Execute a shell command, returning both stdout and stderr. Convenience
2343  * function, as all the arguments to wfShellExec can become unwieldy.
2344  *
2345  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2346  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2347  *   or an array of unescaped arguments, in which case each value will be escaped
2348  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2349  * @param null|mixed &$retval Optional, will receive the program's exit code.
2350  *   (non-zero is usually failure)
2351  * @param array $environ Optional environment variables which should be
2352  *   added to the executed command environment.
2353  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2354  *   this overwrites the global wgMaxShell* limits.
2355  * @return string Collected stdout and stderr as a string
2356  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2357  */
2358 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2359         return wfShellExec( $cmd, $retval, $environ, $limits,
2360                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2361 }
2362
2363 /**
2364  * Formerly set the locale for locale-sensitive operations
2365  *
2366  * This is now done in Setup.php.
2367  *
2368  * @deprecated since 1.30, no longer needed
2369  * @see $wgShellLocale
2370  */
2371 function wfInitShellLocale() {
2372         wfDeprecated( __FUNCTION__, '1.30' );
2373 }
2374
2375 /**
2376  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2377  * Note that $parameters should be a flat array and an option with an argument
2378  * should consist of two consecutive items in the array (do not use "--option value").
2379  *
2380  * @param string $script MediaWiki cli script path
2381  * @param array $parameters Arguments and options to the script
2382  * @param array $options Associative array of options:
2383  *     'php': The path to the php executable
2384  *     'wrapper': Path to a PHP wrapper to handle the maintenance script
2385  * @return string
2386  */
2387 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2388         global $wgPhpCli;
2389         // Give site config file a chance to run the script in a wrapper.
2390         // The caller may likely want to call wfBasename() on $script.
2391         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2392         $cmd = isset( $options['php'] ) ? [ $options['php'] ] : [ $wgPhpCli ];
2393         if ( isset( $options['wrapper'] ) ) {
2394                 $cmd[] = $options['wrapper'];
2395         }
2396         $cmd[] = $script;
2397         // Escape each parameter for shell
2398         return Shell::escape( array_merge( $cmd, $parameters ) );
2399 }
2400
2401 /**
2402  * wfMerge attempts to merge differences between three texts.
2403  * Returns true for a clean merge and false for failure or a conflict.
2404  *
2405  * @param string $old
2406  * @param string $mine
2407  * @param string $yours
2408  * @param string &$result
2409  * @param string &$mergeAttemptResult
2410  * @return bool
2411  */
2412 function wfMerge( $old, $mine, $yours, &$result, &$mergeAttemptResult = null ) {
2413         global $wgDiff3;
2414
2415         # This check may also protect against code injection in
2416         # case of broken installations.
2417         Wikimedia\suppressWarnings();
2418         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2419         Wikimedia\restoreWarnings();
2420
2421         if ( !$haveDiff3 ) {
2422                 wfDebug( "diff3 not found\n" );
2423                 return false;
2424         }
2425
2426         # Make temporary files
2427         $td = wfTempDir();
2428         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2429         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2430         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2431
2432         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2433         #       a newline character. To avoid this, we normalize the trailing whitespace before
2434         #       creating the diff.
2435
2436         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2437         fclose( $oldtextFile );
2438         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2439         fclose( $mytextFile );
2440         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2441         fclose( $yourtextFile );
2442
2443         # Check for a conflict
2444         $cmd = Shell::escape( $wgDiff3, '-a', '--overlap-only', $mytextName,
2445                 $oldtextName, $yourtextName );
2446         $handle = popen( $cmd, 'r' );
2447
2448         $mergeAttemptResult = '';
2449         do {
2450                 $data = fread( $handle, 8192 );
2451                 if ( strlen( $data ) == 0 ) {
2452                         break;
2453                 }
2454                 $mergeAttemptResult .= $data;
2455         } while ( true );
2456         pclose( $handle );
2457
2458         $conflict = $mergeAttemptResult !== '';
2459
2460         # Merge differences
2461         $cmd = Shell::escape( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2462                 $oldtextName, $yourtextName );
2463         $handle = popen( $cmd, 'r' );
2464         $result = '';
2465         do {
2466                 $data = fread( $handle, 8192 );
2467                 if ( strlen( $data ) == 0 ) {
2468                         break;
2469                 }
2470                 $result .= $data;
2471         } while ( true );
2472         pclose( $handle );
2473         unlink( $mytextName );
2474         unlink( $oldtextName );
2475         unlink( $yourtextName );
2476
2477         if ( $result === '' && $old !== '' && !$conflict ) {
2478                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2479                 $conflict = true;
2480         }
2481         return !$conflict;
2482 }
2483
2484 /**
2485  * Returns unified plain-text diff of two texts.
2486  * "Useful" for machine processing of diffs.
2487  *
2488  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2489  *
2490  * @param string $before The text before the changes.
2491  * @param string $after The text after the changes.
2492  * @param string $params Command-line options for the diff command.
2493  * @return string Unified diff of $before and $after
2494  */
2495 function wfDiff( $before, $after, $params = '-u' ) {
2496         if ( $before == $after ) {
2497                 return '';
2498         }
2499
2500         global $wgDiff;
2501         Wikimedia\suppressWarnings();
2502         $haveDiff = $wgDiff && file_exists( $wgDiff );
2503         Wikimedia\restoreWarnings();
2504
2505         # This check may also protect against code injection in
2506         # case of broken installations.
2507         if ( !$haveDiff ) {
2508                 wfDebug( "diff executable not found\n" );
2509                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2510                 $format = new UnifiedDiffFormatter();
2511                 return $format->format( $diffs );
2512         }
2513
2514         # Make temporary files
2515         $td = wfTempDir();
2516         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2517         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2518
2519         fwrite( $oldtextFile, $before );
2520         fclose( $oldtextFile );
2521         fwrite( $newtextFile, $after );
2522         fclose( $newtextFile );
2523
2524         // Get the diff of the two files
2525         $cmd = "$wgDiff " . $params . ' ' . Shell::escape( $oldtextName, $newtextName );
2526
2527         $h = popen( $cmd, 'r' );
2528         if ( !$h ) {
2529                 unlink( $oldtextName );
2530                 unlink( $newtextName );
2531                 throw new Exception( __METHOD__ . '(): popen() failed' );
2532         }
2533
2534         $diff = '';
2535
2536         do {
2537                 $data = fread( $h, 8192 );
2538                 if ( strlen( $data ) == 0 ) {
2539                         break;
2540                 }
2541                 $diff .= $data;
2542         } while ( true );
2543
2544         // Clean up
2545         pclose( $h );
2546         unlink( $oldtextName );
2547         unlink( $newtextName );
2548
2549         // Kill the --- and +++ lines. They're not useful.
2550         $diff_lines = explode( "\n", $diff );
2551         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2552                 unset( $diff_lines[0] );
2553         }
2554         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2555                 unset( $diff_lines[1] );
2556         }
2557
2558         $diff = implode( "\n", $diff_lines );
2559
2560         return $diff;
2561 }
2562
2563 /**
2564  * This function works like "use VERSION" in Perl, the program will die with a
2565  * backtrace if the current version of PHP is less than the version provided
2566  *
2567  * This is useful for extensions which due to their nature are not kept in sync
2568  * with releases, and might depend on other versions of PHP than the main code
2569  *
2570  * Note: PHP might die due to parsing errors in some cases before it ever
2571  *       manages to call this function, such is life
2572  *
2573  * @see perldoc -f use
2574  *
2575  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2576  *
2577  * @deprecated since 1.30
2578  *
2579  * @throws MWException
2580  */
2581 function wfUsePHP( $req_ver ) {
2582         $php_ver = PHP_VERSION;
2583
2584         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2585                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2586         }
2587 }
2588
2589 /**
2590  * This function works like "use VERSION" in Perl except it checks the version
2591  * of MediaWiki, the program will die with a backtrace if the current version
2592  * of MediaWiki is less than the version provided.
2593  *
2594  * This is useful for extensions which due to their nature are not kept in sync
2595  * with releases
2596  *
2597  * Note: Due to the behavior of PHP's version_compare() which is used in this
2598  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2599  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2600  * targeted version number. For example if you wanted to allow any variation
2601  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2602  * not result in the same comparison due to the internal logic of
2603  * version_compare().
2604  *
2605  * @see perldoc -f use
2606  *
2607  * @deprecated since 1.26, use the "requires" property of extension.json
2608  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2609  * @throws MWException
2610  */
2611 function wfUseMW( $req_ver ) {
2612         global $wgVersion;
2613
2614         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2615                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2616         }
2617 }
2618
2619 /**
2620  * Return the final portion of a pathname.
2621  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2622  * https://bugs.php.net/bug.php?id=33898
2623  *
2624  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2625  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2626  *
2627  * @param string $path
2628  * @param string $suffix String to remove if present
2629  * @return string
2630  */
2631 function wfBaseName( $path, $suffix = '' ) {
2632         if ( $suffix == '' ) {
2633                 $encSuffix = '';
2634         } else {
2635                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2636         }
2637
2638         $matches = [];
2639         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2640                 return $matches[1];
2641         } else {
2642                 return '';
2643         }
2644 }
2645
2646 /**
2647  * Generate a relative path name to the given file.
2648  * May explode on non-matching case-insensitive paths,
2649  * funky symlinks, etc.
2650  *
2651  * @param string $path Absolute destination path including target filename
2652  * @param string $from Absolute source path, directory only
2653  * @return string
2654  */
2655 function wfRelativePath( $path, $from ) {
2656         // Normalize mixed input on Windows...
2657         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2658         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2659
2660         // Trim trailing slashes -- fix for drive root
2661         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2662         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2663
2664         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2665         $against = explode( DIRECTORY_SEPARATOR, $from );
2666
2667         if ( $pieces[0] !== $against[0] ) {
2668                 // Non-matching Windows drive letters?
2669                 // Return a full path.
2670                 return $path;
2671         }
2672
2673         // Trim off common prefix
2674         while ( count( $pieces ) && count( $against )
2675                 && $pieces[0] == $against[0] ) {
2676                 array_shift( $pieces );
2677                 array_shift( $against );
2678         }
2679
2680         // relative dots to bump us to the parent
2681         while ( count( $against ) ) {
2682                 array_unshift( $pieces, '..' );
2683                 array_shift( $against );
2684         }
2685
2686         array_push( $pieces, wfBaseName( $path ) );
2687
2688         return implode( DIRECTORY_SEPARATOR, $pieces );
2689 }
2690
2691 /**
2692  * Reset the session id
2693  *
2694  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2695  * @since 1.22
2696  */
2697 function wfResetSessionID() {
2698         wfDeprecated( __FUNCTION__, '1.27' );
2699         $session = SessionManager::getGlobalSession();
2700         $delay = $session->delaySave();
2701
2702         $session->resetId();
2703
2704         // Make sure a session is started, since that's what the old
2705         // wfResetSessionID() did.
2706         if ( session_id() !== $session->getId() ) {
2707                 wfSetupSession( $session->getId() );
2708         }
2709
2710         ScopedCallback::consume( $delay );
2711 }
2712
2713 /**
2714  * Initialise php session
2715  *
2716  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2717  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2718  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2719  *  here), then calling $session->persist().
2720  * @param bool|string $sessionId
2721  */
2722 function wfSetupSession( $sessionId = false ) {
2723         wfDeprecated( __FUNCTION__, '1.27' );
2724
2725         if ( $sessionId ) {
2726                 session_id( $sessionId );
2727         }
2728
2729         $session = SessionManager::getGlobalSession();
2730         $session->persist();
2731
2732         if ( session_id() !== $session->getId() ) {
2733                 session_id( $session->getId() );
2734         }
2735         Wikimedia\quietCall( 'session_start' );
2736 }
2737
2738 /**
2739  * Get an object from the precompiled serialized directory
2740  *
2741  * @param string $name
2742  * @return mixed The variable on success, false on failure
2743  */
2744 function wfGetPrecompiledData( $name ) {
2745         global $IP;
2746
2747         $file = "$IP/serialized/$name";
2748         if ( file_exists( $file ) ) {
2749                 $blob = file_get_contents( $file );
2750                 if ( $blob ) {
2751                         return unserialize( $blob );
2752                 }
2753         }
2754         return false;
2755 }
2756
2757 /**
2758  * Make a cache key for the local wiki.
2759  *
2760  * @deprecated since 1.30 Call makeKey on a BagOStuff instance
2761  * @param string $args,...
2762  * @return string
2763  */
2764 function wfMemcKey( /*...*/ ) {
2765         return call_user_func_array(
2766                 [ ObjectCache::getLocalClusterInstance(), 'makeKey' ],
2767                 func_get_args()
2768         );
2769 }
2770
2771 /**
2772  * Make a cache key for a foreign DB.
2773  *
2774  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2775  *
2776  * @param string $db
2777  * @param string $prefix
2778  * @param string $args,...
2779  * @return string
2780  */
2781 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
2782         $args = array_slice( func_get_args(), 2 );
2783         $keyspace = $prefix ? "$db-$prefix" : $db;
2784         return call_user_func_array(
2785                 [ ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ],
2786                 [ $keyspace, $args ]
2787         );
2788 }
2789
2790 /**
2791  * Make a cache key with database-agnostic prefix.
2792  *
2793  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
2794  * instead. Must have a prefix as otherwise keys that use a database name
2795  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
2796  *
2797  * @deprecated since 1.30 Call makeGlobalKey on a BagOStuff instance
2798  * @since 1.26
2799  * @param string $args,...
2800  * @return string
2801  */
2802 function wfGlobalCacheKey( /*...*/ ) {
2803         return call_user_func_array(
2804                 [ ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ],
2805                 func_get_args()
2806         );
2807 }
2808
2809 /**
2810  * Get an ASCII string identifying this wiki
2811  * This is used as a prefix in memcached keys
2812  *
2813  * @return string
2814  */
2815 function wfWikiID() {
2816         global $wgDBprefix, $wgDBname;
2817         if ( $wgDBprefix ) {
2818                 return "$wgDBname-$wgDBprefix";
2819         } else {
2820                 return $wgDBname;
2821         }
2822 }
2823
2824 /**
2825  * Split a wiki ID into DB name and table prefix
2826  *
2827  * @param string $wiki
2828  *
2829  * @return array
2830  */
2831 function wfSplitWikiID( $wiki ) {
2832         $bits = explode( '-', $wiki, 2 );
2833         if ( count( $bits ) < 2 ) {
2834                 $bits[] = '';
2835         }
2836         return $bits;
2837 }
2838
2839 /**
2840  * Get a Database object.
2841  *
2842  * @param int $db Index of the connection to get. May be DB_MASTER for the
2843  *            master (for write queries), DB_REPLICA for potentially lagged read
2844  *            queries, or an integer >= 0 for a particular server.
2845  *
2846  * @param string|string[] $groups Query groups. An array of group names that this query
2847  *                belongs to. May contain a single string if the query is only
2848  *                in one group.
2849  *
2850  * @param string|bool $wiki The wiki ID, or false for the current wiki
2851  *
2852  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
2853  * will always return the same object, unless the underlying connection or load
2854  * balancer is manually destroyed.
2855  *
2856  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
2857  * updater to ensure that a proper database is being updated.
2858  *
2859  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
2860  *       on an injected instance of LoadBalancer.
2861  *
2862  * @return \Wikimedia\Rdbms\Database
2863  */
2864 function wfGetDB( $db, $groups = [], $wiki = false ) {
2865         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
2866 }
2867
2868 /**
2869  * Get a load balancer object.
2870  *
2871  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancer()
2872  *              or MediaWikiServices::getDBLoadBalancerFactory() instead.
2873  *
2874  * @param string|bool $wiki Wiki ID, or false for the current wiki
2875  * @return \Wikimedia\Rdbms\LoadBalancer
2876  */
2877 function wfGetLB( $wiki = false ) {
2878         if ( $wiki === false ) {
2879                 return MediaWikiServices::getInstance()->getDBLoadBalancer();
2880         } else {
2881                 $factory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2882                 return $factory->getMainLB( $wiki );
2883         }
2884 }
2885
2886 /**
2887  * Get the load balancer factory object
2888  *
2889  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancerFactory() instead.
2890  *
2891  * @return \Wikimedia\Rdbms\LBFactory
2892  */
2893 function wfGetLBFactory() {
2894         return MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2895 }
2896
2897 /**
2898  * Find a file.
2899  * Shortcut for RepoGroup::singleton()->findFile()
2900  *
2901  * @param string|Title $title String or Title object
2902  * @param array $options Associative array of options (see RepoGroup::findFile)
2903  * @return File|bool File, or false if the file does not exist
2904  */
2905 function wfFindFile( $title, $options = [] ) {
2906         return RepoGroup::singleton()->findFile( $title, $options );
2907 }
2908
2909 /**
2910  * Get an object referring to a locally registered file.
2911  * Returns a valid placeholder object if the file does not exist.
2912  *
2913  * @param Title|string $title
2914  * @return LocalFile|null A File, or null if passed an invalid Title
2915  */
2916 function wfLocalFile( $title ) {
2917         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
2918 }
2919
2920 /**
2921  * Should low-performance queries be disabled?
2922  *
2923  * @return bool
2924  * @codeCoverageIgnore
2925  */
2926 function wfQueriesMustScale() {
2927         global $wgMiserMode;
2928         return $wgMiserMode
2929                 || ( SiteStats::pages() > 100000
2930                 && SiteStats::edits() > 1000000
2931                 && SiteStats::users() > 10000 );
2932 }
2933
2934 /**
2935  * Get the path to a specified script file, respecting file
2936  * extensions; this is a wrapper around $wgScriptPath etc.
2937  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
2938  *
2939  * @param string $script Script filename, sans extension
2940  * @return string
2941  */
2942 function wfScript( $script = 'index' ) {
2943         global $wgScriptPath, $wgScript, $wgLoadScript;
2944         if ( $script === 'index' ) {
2945                 return $wgScript;
2946         } elseif ( $script === 'load' ) {
2947                 return $wgLoadScript;
2948         } else {
2949                 return "{$wgScriptPath}/{$script}.php";
2950         }
2951 }
2952
2953 /**
2954  * Get the script URL.
2955  *
2956  * @return string Script URL
2957  */
2958 function wfGetScriptUrl() {
2959         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
2960                 /* as it was called, minus the query string.
2961                  *
2962                  * Some sites use Apache rewrite rules to handle subdomains,
2963                  * and have PHP set up in a weird way that causes PHP_SELF
2964                  * to contain the rewritten URL instead of the one that the
2965                  * outside world sees.
2966                  *
2967                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
2968                  * provides containing the "before" URL.
2969                  */
2970                 return $_SERVER['SCRIPT_NAME'];
2971         } else {
2972                 return $_SERVER['URL'];
2973         }
2974 }
2975
2976 /**
2977  * Convenience function converts boolean values into "true"
2978  * or "false" (string) values
2979  *
2980  * @param bool $value
2981  * @return string
2982  */
2983 function wfBoolToStr( $value ) {
2984         return $value ? 'true' : 'false';
2985 }
2986
2987 /**
2988  * Get a platform-independent path to the null file, e.g. /dev/null
2989  *
2990  * @return string
2991  */
2992 function wfGetNull() {
2993         return wfIsWindows() ? 'NUL' : '/dev/null';
2994 }
2995
2996 /**
2997  * Waits for the replica DBs to catch up to the master position
2998  *
2999  * Use this when updating very large numbers of rows, as in maintenance scripts,
3000  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
3001  *
3002  * By default this waits on the main DB cluster of the current wiki.
3003  * If $cluster is set to "*" it will wait on all DB clusters, including
3004  * external ones. If the lag being waiting on is caused by the code that
3005  * does this check, it makes since to use $ifWritesSince, particularly if
3006  * cluster is "*", to avoid excess overhead.
3007  *
3008  * Never call this function after a big DB write that is still in a transaction.
3009  * This only makes sense after the possible lag inducing changes were committed.
3010  *
3011  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3012  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3013  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3014  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3015  * @return bool Success (able to connect and no timeouts reached)
3016  * @deprecated since 1.27 Use LBFactory::waitForReplication
3017  */
3018 function wfWaitForSlaves(
3019         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3020 ) {
3021         if ( $timeout === null ) {
3022                 $timeout = wfIsCLI() ? 86400 : 10;
3023         }
3024
3025         if ( $cluster === '*' ) {
3026                 $cluster = false;
3027                 $wiki = false;
3028         } elseif ( $wiki === false ) {
3029                 $wiki = wfWikiID();
3030         }
3031
3032         try {
3033                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
3034                 $lbFactory->waitForReplication( [
3035                         'wiki' => $wiki,
3036                         'cluster' => $cluster,
3037                         'timeout' => $timeout,
3038                         // B/C: first argument used to be "max seconds of lag"; ignore such values
3039                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
3040                 ] );
3041         } catch ( DBReplicationWaitError $e ) {
3042                 return false;
3043         }
3044
3045         return true;
3046 }
3047
3048 /**
3049  * Count down from $seconds to zero on the terminal, with a one-second pause
3050  * between showing each number. For use in command-line scripts.
3051  *
3052  * @deprecated since 1.31, use Maintenance::countDown()
3053  *
3054  * @codeCoverageIgnore
3055  * @param int $seconds
3056  */
3057 function wfCountDown( $seconds ) {
3058         for ( $i = $seconds; $i >= 0; $i-- ) {
3059                 if ( $i != $seconds ) {
3060                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3061                 }
3062                 echo $i;
3063                 flush();
3064                 if ( $i ) {
3065                         sleep( 1 );
3066                 }
3067         }
3068         echo "\n";
3069 }
3070
3071 /**
3072  * Replace all invalid characters with '-'.
3073  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
3074  * By default, $wgIllegalFileChars includes ':', '/', '\'.
3075  *
3076  * @param string $name Filename to process
3077  * @return string
3078  */
3079 function wfStripIllegalFilenameChars( $name ) {
3080         global $wgIllegalFileChars;
3081         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3082         $name = preg_replace(
3083                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3084                 '-',
3085                 $name
3086         );
3087         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
3088         $name = wfBaseName( $name );
3089         return $name;
3090 }
3091
3092 /**
3093  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3094  *
3095  * @return int Resulting value of the memory limit.
3096  */
3097 function wfMemoryLimit() {
3098         global $wgMemoryLimit;
3099         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3100         if ( $memlimit != -1 ) {
3101                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3102                 if ( $conflimit == -1 ) {
3103                         wfDebug( "Removing PHP's memory limit\n" );
3104                         Wikimedia\suppressWarnings();
3105                         ini_set( 'memory_limit', $conflimit );
3106                         Wikimedia\restoreWarnings();
3107                         return $conflimit;
3108                 } elseif ( $conflimit > $memlimit ) {
3109                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3110                         Wikimedia\suppressWarnings();
3111                         ini_set( 'memory_limit', $conflimit );
3112                         Wikimedia\restoreWarnings();
3113                         return $conflimit;
3114                 }
3115         }
3116         return $memlimit;
3117 }
3118
3119 /**
3120  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3121  *
3122  * @return int Prior time limit
3123  * @since 1.26
3124  */
3125 function wfTransactionalTimeLimit() {
3126         global $wgTransactionalTimeLimit;
3127
3128         $timeLimit = ini_get( 'max_execution_time' );
3129         // Note that CLI scripts use 0
3130         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3131                 set_time_limit( $wgTransactionalTimeLimit );
3132         }
3133
3134         ignore_user_abort( true ); // ignore client disconnects
3135
3136         return $timeLimit;
3137 }
3138
3139 /**
3140  * Converts shorthand byte notation to integer form
3141  *
3142  * @param string $string
3143  * @param int $default Returned if $string is empty
3144  * @return int
3145  */
3146 function wfShorthandToInteger( $string = '', $default = -1 ) {
3147         $string = trim( $string );
3148         if ( $string === '' ) {
3149                 return $default;
3150         }
3151         $last = $string[strlen( $string ) - 1];
3152         $val = intval( $string );
3153         switch ( $last ) {
3154                 case 'g':
3155                 case 'G':
3156                         $val *= 1024;
3157                         // break intentionally missing
3158                 case 'm':
3159                 case 'M':
3160                         $val *= 1024;
3161                         // break intentionally missing
3162                 case 'k':
3163                 case 'K':
3164                         $val *= 1024;
3165         }
3166
3167         return $val;
3168 }
3169
3170 /**
3171  * Get the normalised IETF language tag
3172  * See unit test for examples.
3173  * See mediawiki.language.bcp47 for the JavaScript implementation.
3174  *
3175  * @deprecated since 1.31, use LanguageCode::bcp47() directly.
3176  *
3177  * @param string $code The language code.
3178  * @return string The language code which complying with BCP 47 standards.
3179  */
3180 function wfBCP47( $code ) {
3181         return LanguageCode::bcp47( $code );
3182 }
3183
3184 /**
3185  * Get a specific cache object.
3186  *
3187  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3188  * @return BagOStuff
3189  */
3190 function wfGetCache( $cacheType ) {
3191         return ObjectCache::getInstance( $cacheType );
3192 }
3193
3194 /**
3195  * Get the main cache object
3196  *
3197  * @return BagOStuff
3198  */
3199 function wfGetMainCache() {
3200         global $wgMainCacheType;
3201         return ObjectCache::getInstance( $wgMainCacheType );
3202 }
3203
3204 /**
3205  * Get the cache object used by the message cache
3206  *
3207  * @return BagOStuff
3208  */
3209 function wfGetMessageCacheStorage() {
3210         global $wgMessageCacheType;
3211         return ObjectCache::getInstance( $wgMessageCacheType );
3212 }
3213
3214 /**
3215  * Get the cache object used by the parser cache
3216  *
3217  * @deprecated since 1.30, use MediaWikiServices::getParserCache()->getCacheStorage()
3218  * @return BagOStuff
3219  */
3220 function wfGetParserCacheStorage() {
3221         global $wgParserCacheType;
3222         return ObjectCache::getInstance( $wgParserCacheType );
3223 }
3224
3225 /**
3226  * Call hook functions defined in $wgHooks
3227  *
3228  * @param string $event Event name
3229  * @param array $args Parameters passed to hook functions
3230  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3231  *
3232  * @return bool True if no handler aborted the hook
3233  * @deprecated since 1.25 - use Hooks::run
3234  */
3235 function wfRunHooks( $event, array $args = [], $deprecatedVersion = null ) {
3236         wfDeprecated( __METHOD__, '1.25' );
3237         return Hooks::run( $event, $args, $deprecatedVersion );
3238 }
3239
3240 /**
3241  * Wrapper around php's unpack.
3242  *
3243  * @param string $format The format string (See php's docs)
3244  * @param string $data A binary string of binary data
3245  * @param int|bool $length The minimum length of $data or false. This is to
3246  *      prevent reading beyond the end of $data. false to disable the check.
3247  *
3248  * Also be careful when using this function to read unsigned 32 bit integer
3249  * because php might make it negative.
3250  *
3251  * @throws MWException If $data not long enough, or if unpack fails
3252  * @return array Associative array of the extracted data
3253  */
3254 function wfUnpack( $format, $data, $length = false ) {
3255         if ( $length !== false ) {
3256                 $realLen = strlen( $data );
3257                 if ( $realLen < $length ) {
3258                         throw new MWException( "Tried to use wfUnpack on a "
3259                                 . "string of length $realLen, but needed one "
3260                                 . "of at least length $length."
3261                         );
3262                 }
3263         }
3264
3265         Wikimedia\suppressWarnings();
3266         $result = unpack( $format, $data );
3267         Wikimedia\restoreWarnings();
3268
3269         if ( $result === false ) {
3270                 // If it cannot extract the packed data.
3271                 throw new MWException( "unpack could not unpack binary data" );
3272         }
3273         return $result;
3274 }
3275
3276 /**
3277  * Determine if an image exists on the 'bad image list'.
3278  *
3279  * The format of MediaWiki:Bad_image_list is as follows:
3280  *    * Only list items (lines starting with "*") are considered
3281  *    * The first link on a line must be a link to a bad image
3282  *    * Any subsequent links on the same line are considered to be exceptions,
3283  *      i.e. articles where the image may occur inline.
3284  *
3285  * @param string $name The image name to check
3286  * @param Title|bool $contextTitle The page on which the image occurs, if known
3287  * @param string $blacklist Wikitext of a file blacklist
3288  * @return bool
3289  */
3290 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3291         # Handle redirects; callers almost always hit wfFindFile() anyway,
3292         # so just use that method because it has a fast process cache.
3293         $file = wfFindFile( $name ); // get the final name
3294         $name = $file ? $file->getTitle()->getDBkey() : $name;
3295
3296         # Run the extension hook
3297         $bad = false;
3298         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3299                 return (bool)$bad;
3300         }
3301
3302         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3303         $key = $cache->makeKey(
3304                 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist )
3305         );
3306         $badImages = $cache->get( $key );
3307
3308         if ( $badImages === false ) { // cache miss
3309                 if ( $blacklist === null ) {
3310                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3311                 }
3312                 # Build the list now
3313                 $badImages = [];
3314                 $lines = explode( "\n", $blacklist );
3315                 foreach ( $lines as $line ) {
3316                         # List items only
3317                         if ( substr( $line, 0, 1 ) !== '*' ) {
3318                                 continue;
3319                         }
3320
3321                         # Find all links
3322                         $m = [];
3323                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3324                                 continue;
3325                         }
3326
3327                         $exceptions = [];
3328                         $imageDBkey = false;
3329                         foreach ( $m[1] as $i => $titleText ) {
3330                                 $title = Title::newFromText( $titleText );
3331                                 if ( !is_null( $title ) ) {
3332                                         if ( $i == 0 ) {
3333                                                 $imageDBkey = $title->getDBkey();
3334                                         } else {
3335                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3336                                         }
3337                                 }
3338                         }
3339
3340                         if ( $imageDBkey !== false ) {
3341                                 $badImages[$imageDBkey] = $exceptions;
3342                         }
3343                 }
3344                 $cache->set( $key, $badImages, 60 );
3345         }
3346
3347         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3348         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3349
3350         return $bad;
3351 }
3352
3353 /**
3354  * Determine whether the client at a given source IP is likely to be able to
3355  * access the wiki via HTTPS.
3356  *
3357  * @param string $ip The IPv4/6 address in the normal human-readable form
3358  * @return bool
3359  */
3360 function wfCanIPUseHTTPS( $ip ) {
3361         $canDo = true;
3362         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3363         return !!$canDo;
3364 }
3365
3366 /**
3367  * Determine input string is represents as infinity
3368  *
3369  * @param string $str The string to determine
3370  * @return bool
3371  * @since 1.25
3372  */
3373 function wfIsInfinity( $str ) {
3374         // These are hardcoded elsewhere in MediaWiki (e.g. mediawiki.special.block.js).
3375         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3376         return in_array( $str, $infinityValues );
3377 }
3378
3379 /**
3380  * Returns true if these thumbnail parameters match one that MediaWiki
3381  * requests from file description pages and/or parser output.
3382  *
3383  * $params is considered non-standard if they involve a non-standard
3384  * width or any non-default parameters aside from width and page number.
3385  * The number of possible files with standard parameters is far less than
3386  * that of all combinations; rate-limiting for them can thus be more generious.
3387  *
3388  * @param File $file
3389  * @param array $params
3390  * @return bool
3391  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3392  */
3393 function wfThumbIsStandard( File $file, array $params ) {
3394         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3395
3396         $multipliers = [ 1 ];
3397         if ( $wgResponsiveImages ) {
3398                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3399                 // @see Linker::processResponsiveImages
3400                 $multipliers[] = 1.5;
3401                 $multipliers[] = 2;
3402         }
3403
3404         $handler = $file->getHandler();
3405         if ( !$handler || !isset( $params['width'] ) ) {
3406                 return false;
3407         }
3408
3409         $basicParams = [];
3410         if ( isset( $params['page'] ) ) {
3411                 $basicParams['page'] = $params['page'];
3412         }
3413
3414         $thumbLimits = [];
3415         $imageLimits = [];
3416         // Expand limits to account for multipliers
3417         foreach ( $multipliers as $multiplier ) {
3418                 $thumbLimits = array_merge( $thumbLimits, array_map(
3419                         function ( $width ) use ( $multiplier ) {
3420                                 return round( $width * $multiplier );
3421                         }, $wgThumbLimits )
3422                 );
3423                 $imageLimits = array_merge( $imageLimits, array_map(
3424                         function ( $pair ) use ( $multiplier ) {
3425                                 return [
3426                                         round( $pair[0] * $multiplier ),
3427                                         round( $pair[1] * $multiplier ),
3428                                 ];
3429                         }, $wgImageLimits )
3430                 );
3431         }
3432
3433         // Check if the width matches one of $wgThumbLimits
3434         if ( in_array( $params['width'], $thumbLimits ) ) {
3435                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3436                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3437                 $handler->normaliseParams( $file, $normalParams );
3438         } else {
3439                 // If not, then check if the width matchs one of $wgImageLimits
3440                 $match = false;
3441                 foreach ( $imageLimits as $pair ) {
3442                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3443                         // Decide whether the thumbnail should be scaled on width or height.
3444                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3445                         $handler->normaliseParams( $file, $normalParams );
3446                         // Check if this standard thumbnail size maps to the given width
3447                         if ( $normalParams['width'] == $params['width'] ) {
3448                                 $match = true;
3449                                 break;
3450                         }
3451                 }
3452                 if ( !$match ) {
3453                         return false; // not standard for description pages
3454                 }
3455         }
3456
3457         // Check that the given values for non-page, non-width, params are just defaults
3458         foreach ( $params as $key => $value ) {
3459                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3460                         return false;
3461                 }
3462         }
3463
3464         return true;
3465 }
3466
3467 /**
3468  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3469  *
3470  * Values that exist in both values will be combined with += (all values of the array
3471  * of $newValues will be added to the values of the array of $baseArray, while values,
3472  * that exists in both, the value of $baseArray will be used).
3473  *
3474  * @param array $baseArray The array where you want to add the values of $newValues to
3475  * @param array $newValues An array with new values
3476  * @return array The combined array
3477  * @since 1.26
3478  */
3479 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3480         // First merge items that are in both arrays
3481         foreach ( $baseArray as $name => &$groupVal ) {
3482                 if ( isset( $newValues[$name] ) ) {
3483                         $groupVal += $newValues[$name];
3484                 }
3485         }
3486         // Now add items that didn't exist yet
3487         $baseArray += $newValues;
3488
3489         return $baseArray;
3490 }
3491
3492 /**
3493  * Get system resource usage of current request context.
3494  * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
3495  * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
3496  *
3497  * @since 1.24
3498  * @return array|bool Resource usage data or false if no data available.
3499  */
3500 function wfGetRusage() {
3501         if ( !function_exists( 'getrusage' ) ) {
3502                 return false;
3503         } elseif ( defined( 'HHVM_VERSION' ) && PHP_OS === 'Linux' ) {
3504                 return getrusage( 2 /* RUSAGE_THREAD */ );
3505         } else {
3506                 return getrusage( 0 /* RUSAGE_SELF */ );
3507         }
3508 }