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 Liuggio\StatsdClient\Sender\SocketSender;
  28 use MediaWiki\Logger\LoggerFactory;
  29 use MediaWiki\ProcOpenError;
  30 use MediaWiki\Session\SessionManager;
  31 use MediaWiki\MediaWikiServices;
  32 use MediaWiki\Shell\Shell;
  33 use Wikimedia\ScopedCallback;
  34 use Wikimedia\Rdbms\DBReplicationWaitError;
  35
  36 // Hide compatibility functions from Doxygen
  37 /// @cond
  38 /**
  39  * Compatibility functions
  40  *
  41  * We support PHP 5.5.9 and up.
  42  * Re-implementations of newer functions or functions in non-standard
  43  * PHP extensions may be included here.
  44  */
  45
  46 // hash_equals function only exists in PHP >= 5.6.0
  47 // https://secure.php.net/hash_equals
  48 if ( !function_exists( 'hash_equals' ) ) {
  49         /**
  50          * Check whether a user-provided string is equal to a fixed-length secret string
  51          * without revealing bytes of the secret string through timing differences.
  52          *
  53          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
  54          * function in C) is to compare corresponding bytes and stop at the first difference,
  55          * which would take longer for a partial match than for a complete mismatch. This
  56          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
  57          * and the other may come from an attacker. Statistical analysis of timing measurements
  58          * over many requests may allow the attacker to guess the string's bytes one at a time
  59          * (and check his guesses) even if the timing differences are extremely small.
  60          *
  61          * When making such a security-sensitive comparison, it is essential that the sequence
  62          * in which instructions are executed and memory locations are accessed not depend on
  63          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
  64          * the inevitable leakage of the string's length. That is generally known anyway as
  65          * a chararacteristic of the hash function used to compute the secret value.
  66          *
  67          * Longer explanation: http://www.emerose.com/timing-attacks-explained
  68          *
  69          * @codeCoverageIgnore
  70          * @param string $known_string Fixed-length secret string to compare against
  71          * @param string $user_string User-provided string
  72          * @return bool True if the strings are the same, false otherwise
  73          */
  74         function hash_equals( $known_string, $user_string ) {
  75                 // Strict type checking as in PHP's native implementation
  76                 if ( !is_string( $known_string ) ) {
  77                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
  78                                 gettype( $known_string ) . ' given', E_USER_WARNING );
  79
  80                         return false;
  81                 }
  82
  83                 if ( !is_string( $user_string ) ) {
  84                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
  85                                 gettype( $user_string ) . ' given', E_USER_WARNING );
  86
  87                         return false;
  88                 }
  89
  90                 $known_string_len = strlen( $known_string );
  91                 if ( $known_string_len !== strlen( $user_string ) ) {
  92                         return false;
  93                 }
  94
  95                 $result = 0;
  96                 for ( $i = 0; $i < $known_string_len; $i++ ) {
  97                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
  98                 }
  99
 100                 return ( $result === 0 );
 101         }
 102 }
 103 /// @endcond
 104
 105 /**
 106  * Load an extension
 107  *
 108  * This queues an extension to be loaded through
 109  * the ExtensionRegistry system.
 110  *
 111  * @param string $ext Name of the extension to load
 112  * @param string|null $path Absolute path of where to find the extension.json file
 113  * @since 1.25
 114  */
 115 function wfLoadExtension( $ext, $path = null ) {
 116         if ( !$path ) {
 117                 global $wgExtensionDirectory;
 118                 $path = "$wgExtensionDirectory/$ext/extension.json";
 119         }
 120         ExtensionRegistry::getInstance()->queue( $path );
 121 }
 122
 123 /**
 124  * Load multiple extensions at once
 125  *
 126  * Same as wfLoadExtension, but more efficient if you
 127  * are loading multiple extensions.
 128  *
 129  * If you want to specify custom paths, you should interact with
 130  * ExtensionRegistry directly.
 131  *
 132  * @see wfLoadExtension
 133  * @param string[] $exts Array of extension names to load
 134  * @since 1.25
 135  */
 136 function wfLoadExtensions( array $exts ) {
 137         global $wgExtensionDirectory;
 138         $registry = ExtensionRegistry::getInstance();
 139         foreach ( $exts as $ext ) {
 140                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 141         }
 142 }
 143
 144 /**
 145  * Load a skin
 146  *
 147  * @see wfLoadExtension
 148  * @param string $skin Name of the extension to load
 149  * @param string|null $path Absolute path of where to find the skin.json file
 150  * @since 1.25
 151  */
 152 function wfLoadSkin( $skin, $path = null ) {
 153         if ( !$path ) {
 154                 global $wgStyleDirectory;
 155                 $path = "$wgStyleDirectory/$skin/skin.json";
 156         }
 157         ExtensionRegistry::getInstance()->queue( $path );
 158 }
 159
 160 /**
 161  * Load multiple skins at once
 162  *
 163  * @see wfLoadExtensions
 164  * @param string[] $skins Array of extension names to load
 165  * @since 1.25
 166  */
 167 function wfLoadSkins( array $skins ) {
 168         global $wgStyleDirectory;
 169         $registry = ExtensionRegistry::getInstance();
 170         foreach ( $skins as $skin ) {
 171                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 172         }
 173 }
 174
 175 /**
 176  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 177  * @param array $a
 178  * @param array $b
 179  * @return array
 180  */
 181 function wfArrayDiff2( $a, $b ) {
 182         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 183 }
 184
 185 /**
 186  * @param array|string $a
 187  * @param array|string $b
 188  * @return int
 189  */
 190 function wfArrayDiff2_cmp( $a, $b ) {
 191         if ( is_string( $a ) && is_string( $b ) ) {
 192                 return strcmp( $a, $b );
 193         } elseif ( count( $a ) !== count( $b ) ) {
 194                 return count( $a ) < count( $b ) ? -1 : 1;
 195         } else {
 196                 reset( $a );
 197                 reset( $b );
 198                 while ( key( $a ) !== null && key( $b ) !== null ) {
 199                         $valueA = current( $a );
 200                         $valueB = current( $b );
 201                         $cmp = strcmp( $valueA, $valueB );
 202                         if ( $cmp !== 0 ) {
 203                                 return $cmp;
 204                         }
 205                         next( $a );
 206                         next( $b );
 207                 }
 208                 return 0;
 209         }
 210 }
 211
 212 /**
 213  * Like array_filter with ARRAY_FILTER_USE_BOTH, but works pre-5.6.
 214  *
 215  * @param array $arr
 216  * @param callable $callback Will be called with the array value and key (in that order) and
 217  *   should return a bool which will determine whether the array element is kept.
 218  * @return array
 219  */
 220 function wfArrayFilter( array $arr, callable $callback ) {
 221         if ( defined( 'ARRAY_FILTER_USE_BOTH' ) ) {
 222                 return array_filter( $arr, $callback, ARRAY_FILTER_USE_BOTH );
 223         }
 224         $filteredKeys = array_filter( array_keys( $arr ), function ( $key ) use ( $arr, $callback ) {
 225                 return call_user_func( $callback, $arr[$key], $key );
 226         } );
 227         return array_intersect_key( $arr, array_fill_keys( $filteredKeys, true ) );
 228 }
 229
 230 /**
 231  * Like array_filter with ARRAY_FILTER_USE_KEY, but works pre-5.6.
 232  *
 233  * @param array $arr
 234  * @param callable $callback Will be called with the array key and should return a bool which
 235  *   will determine whether the array element is kept.
 236  * @return array
 237  */
 238 function wfArrayFilterByKey( array $arr, callable $callback ) {
 239         return wfArrayFilter( $arr, function ( $val, $key ) use ( $callback ) {
 240                 return call_user_func( $callback, $key );
 241         } );
 242 }
 243
 244 /**
 245  * Appends to second array if $value differs from that in $default
 246  *
 247  * @param string|int $key
 248  * @param mixed $value
 249  * @param mixed $default
 250  * @param array &$changed Array to alter
 251  * @throws MWException
 252  */
 253 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 254         if ( is_null( $changed ) ) {
 255                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 256         }
 257         if ( $default[$key] !== $value ) {
 258                 $changed[$key] = $value;
 259         }
 260 }
 261
 262 /**
 263  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 264  * e.g.
 265  *     wfMergeErrorArrays(
 266  *       [ [ 'x' ] ],
 267  *       [ [ 'x', '2' ] ],
 268  *       [ [ 'x' ] ],
 269  *       [ [ 'y' ] ]
 270  *     );
 271  * returns:
 272  *     [
 273  *       [ 'x', '2' ],
 274  *       [ 'x' ],
 275  *       [ 'y' ]
 276  *     ]
 277  *
 278  * @param array $array1,...
 279  * @return array
 280  */
 281 function wfMergeErrorArrays( /*...*/ ) {
 282         $args = func_get_args();
 283         $out = [];
 284         foreach ( $args as $errors ) {
 285                 foreach ( $errors as $params ) {
 286                         $originalParams = $params;
 287                         if ( $params[0] instanceof MessageSpecifier ) {
 288                                 $msg = $params[0];
 289                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 290                         }
 291                         # @todo FIXME: Sometimes get nested arrays for $params,
 292                         # which leads to E_NOTICEs
 293                         $spec = implode( "\t", $params );
 294                         $out[$spec] = $originalParams;
 295                 }
 296         }
 297         return array_values( $out );
 298 }
 299
 300 /**
 301  * Insert array into another array after the specified *KEY*
 302  *
 303  * @param array $array The array.
 304  * @param array $insert The array to insert.
 305  * @param mixed $after The key to insert after
 306  * @return array
 307  */
 308 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 309         // Find the offset of the element to insert after.
 310         $keys = array_keys( $array );
 311         $offsetByKey = array_flip( $keys );
 312
 313         $offset = $offsetByKey[$after];
 314
 315         // Insert at the specified offset
 316         $before = array_slice( $array, 0, $offset + 1, true );
 317         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 318
 319         $output = $before + $insert + $after;
 320
 321         return $output;
 322 }
 323
 324 /**
 325  * Recursively converts the parameter (an object) to an array with the same data
 326  *
 327  * @param object|array $objOrArray
 328  * @param bool $recursive
 329  * @return array
 330  */
 331 function wfObjectToArray( $objOrArray, $recursive = true ) {
 332         $array = [];
 333         if ( is_object( $objOrArray ) ) {
 334                 $objOrArray = get_object_vars( $objOrArray );
 335         }
 336         foreach ( $objOrArray as $key => $value ) {
 337                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 338                         $value = wfObjectToArray( $value );
 339                 }
 340
 341                 $array[$key] = $value;
 342         }
 343
 344         return $array;
 345 }
 346
 347 /**
 348  * Get a random decimal value between 0 and 1, in a way
 349  * not likely to give duplicate values for any realistic
 350  * number of articles.
 351  *
 352  * @note This is designed for use in relation to Special:RandomPage
 353  *       and the page_random database field.
 354  *
 355  * @return string
 356  */
 357 function wfRandom() {
 358         // The maximum random value is "only" 2^31-1, so get two random
 359         // values to reduce the chance of dupes
 360         $max = mt_getrandmax() + 1;
 361         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 362         return $rand;
 363 }
 364
 365 /**
 366  * Get a random string containing a number of pseudo-random hex characters.
 367  *
 368  * @note This is not secure, if you are trying to generate some sort
 369  *       of token please use MWCryptRand instead.
 370  *
 371  * @param int $length The length of the string to generate
 372  * @return string
 373  * @since 1.20
 374  */
 375 function wfRandomString( $length = 32 ) {
 376         $str = '';
 377         for ( $n = 0; $n < $length; $n += 7 ) {
 378                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 379         }
 380         return substr( $str, 0, $length );
 381 }
 382
 383 /**
 384  * We want some things to be included as literal characters in our title URLs
 385  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 386  * all of the following should be safe:
 387  *
 388  * ;:@&=$-_.+!*'(),
 389  *
 390  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 391  * character which should not be encoded. More importantly, google chrome
 392  * always converts %7E back to ~, and converting it in this function can
 393  * cause a redirect loop (T105265).
 394  *
 395  * But + is not safe because it's used to indicate a space; &= are only safe in
 396  * paths and not in queries (and we don't distinguish here); ' seems kind of
 397  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 398  * is reserved, we don't care.  So the list we unescape is:
 399  *
 400  * ;:@$!*(),/~
 401  *
 402  * However, IIS7 redirects fail when the url contains a colon (see T24709),
 403  * so no fancy : for IIS7.
 404  *
 405  * %2F in the page titles seems to fatally break for some reason.
 406  *
 407  * @param string $s
 408  * @return string
 409  */
 410 function wfUrlencode( $s ) {
 411         static $needle;
 412
 413         if ( is_null( $s ) ) {
 414                 $needle = null;
 415                 return '';
 416         }
 417
 418         if ( is_null( $needle ) ) {
 419                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 420                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 421                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 422                 ) {
 423                         $needle[] = '%3A';
 424                 }
 425         }
 426
 427         $s = urlencode( $s );
 428         $s = str_ireplace(
 429                 $needle,
 430                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 431                 $s
 432         );
 433
 434         return $s;
 435 }
 436
 437 /**
 438  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 439  * "days=7&limit=100". Options in the first array override options in the second.
 440  * Options set to null or false will not be output.
 441  *
 442  * @param array $array1 ( String|Array )
 443  * @param array|null $array2 ( String|Array )
 444  * @param string $prefix
 445  * @return string
 446  */
 447 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 448         if ( !is_null( $array2 ) ) {
 449                 $array1 = $array1 + $array2;
 450         }
 451
 452         $cgi = '';
 453         foreach ( $array1 as $key => $value ) {
 454                 if ( !is_null( $value ) && $value !== false ) {
 455                         if ( $cgi != '' ) {
 456                                 $cgi .= '&';
 457                         }
 458                         if ( $prefix !== '' ) {
 459                                 $key = $prefix . "[$key]";
 460                         }
 461                         if ( is_array( $value ) ) {
 462                                 $firstTime = true;
 463                                 foreach ( $value as $k => $v ) {
 464                                         $cgi .= $firstTime ? '' : '&';
 465                                         if ( is_array( $v ) ) {
 466                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 467                                         } else {
 468                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 469                                         }
 470                                         $firstTime = false;
 471                                 }
 472                         } else {
 473                                 if ( is_object( $value ) ) {
 474                                         $value = $value->__toString();
 475                                 }
 476                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 477                         }
 478                 }
 479         }
 480         return $cgi;
 481 }
 482
 483 /**
 484  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 485  * its argument and returns the same string in array form.  This allows compatibility
 486  * with legacy functions that accept raw query strings instead of nice
 487  * arrays.  Of course, keys and values are urldecode()d.
 488  *
 489  * @param string $query Query string
 490  * @return string[] Array version of input
 491  */
 492 function wfCgiToArray( $query ) {
 493         if ( isset( $query[0] ) && $query[0] == '?' ) {
 494                 $query = substr( $query, 1 );
 495         }
 496         $bits = explode( '&', $query );
 497         $ret = [];
 498         foreach ( $bits as $bit ) {
 499                 if ( $bit === '' ) {
 500                         continue;
 501                 }
 502                 if ( strpos( $bit, '=' ) === false ) {
 503                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 504                         $key = $bit;
 505                         $value = '';
 506                 } else {
 507                         list( $key, $value ) = explode( '=', $bit );
 508                 }
 509                 $key = urldecode( $key );
 510                 $value = urldecode( $value );
 511                 if ( strpos( $key, '[' ) !== false ) {
 512                         $keys = array_reverse( explode( '[', $key ) );
 513                         $key = array_pop( $keys );
 514                         $temp = $value;
 515                         foreach ( $keys as $k ) {
 516                                 $k = substr( $k, 0, -1 );
 517                                 $temp = [ $k => $temp ];
 518                         }
 519                         if ( isset( $ret[$key] ) ) {
 520                                 $ret[$key] = array_merge( $ret[$key], $temp );
 521                         } else {
 522                                 $ret[$key] = $temp;
 523                         }
 524                 } else {
 525                         $ret[$key] = $value;
 526                 }
 527         }
 528         return $ret;
 529 }
 530
 531 /**
 532  * Append a query string to an existing URL, which may or may not already
 533  * have query string parameters already. If so, they will be combined.
 534  *
 535  * @param string $url
 536  * @param string|string[] $query String or associative array
 537  * @return string
 538  */
 539 function wfAppendQuery( $url, $query ) {
 540         if ( is_array( $query ) ) {
 541                 $query = wfArrayToCgi( $query );
 542         }
 543         if ( $query != '' ) {
 544                 // Remove the fragment, if there is one
 545                 $fragment = false;
 546                 $hashPos = strpos( $url, '#' );
 547                 if ( $hashPos !== false ) {
 548                         $fragment = substr( $url, $hashPos );
 549                         $url = substr( $url, 0, $hashPos );
 550                 }
 551
 552                 // Add parameter
 553                 if ( false === strpos( $url, '?' ) ) {
 554                         $url .= '?';
 555                 } else {
 556                         $url .= '&';
 557                 }
 558                 $url .= $query;
 559
 560                 // Put the fragment back
 561                 if ( $fragment !== false ) {
 562                         $url .= $fragment;
 563                 }
 564         }
 565         return $url;
 566 }
 567
 568 /**
 569  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 570  * is correct.
 571  *
 572  * The meaning of the PROTO_* constants is as follows:
 573  * PROTO_HTTP: Output a URL starting with http://
 574  * PROTO_HTTPS: Output a URL starting with https://
 575  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 576  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 577  *    on which protocol was used for the current incoming request
 578  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 579  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 580  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 581  *
 582  * @todo this won't work with current-path-relative URLs
 583  * like "subdir/foo.html", etc.
 584  *
 585  * @param string $url Either fully-qualified or a local path + query
 586  * @param string $defaultProto One of the PROTO_* constants. Determines the
 587  *    protocol to use if $url or $wgServer is protocol-relative
 588  * @return string|false Fully-qualified URL, current-path-relative URL or false if
 589  *    no valid URL can be constructed
 590  */
 591 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 592         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 593                 $wgHttpsPort;
 594         if ( $defaultProto === PROTO_CANONICAL ) {
 595                 $serverUrl = $wgCanonicalServer;
 596         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 597                 // Make $wgInternalServer fall back to $wgServer if not set
 598                 $serverUrl = $wgInternalServer;
 599         } else {
 600                 $serverUrl = $wgServer;
 601                 if ( $defaultProto === PROTO_CURRENT ) {
 602                         $defaultProto = $wgRequest->getProtocol() . '://';
 603                 }
 604         }
 605
 606         // Analyze $serverUrl to obtain its protocol
 607         $bits = wfParseUrl( $serverUrl );
 608         $serverHasProto = $bits && $bits['scheme'] != '';
 609
 610         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 611                 if ( $serverHasProto ) {
 612                         $defaultProto = $bits['scheme'] . '://';
 613                 } else {
 614                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 615                         // This really isn't supposed to happen. Fall back to HTTP in this
 616                         // ridiculous case.
 617                         $defaultProto = PROTO_HTTP;
 618                 }
 619         }
 620
 621         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 622
 623         if ( substr( $url, 0, 2 ) == '//' ) {
 624                 $url = $defaultProtoWithoutSlashes . $url;
 625         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 626                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 627                 // otherwise leave it alone.
 628                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 629         }
 630
 631         $bits = wfParseUrl( $url );
 632
 633         // ensure proper port for HTTPS arrives in URL
 634         // https://phabricator.wikimedia.org/T67184
 635         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 636                 $bits['port'] = $wgHttpsPort;
 637         }
 638
 639         if ( $bits && isset( $bits['path'] ) ) {
 640                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 641                 return wfAssembleUrl( $bits );
 642         } elseif ( $bits ) {
 643                 # No path to expand
 644                 return $url;
 645         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 646                 # URL is a relative path
 647                 return wfRemoveDotSegments( $url );
 648         }
 649
 650         # Expanded URL is not valid.
 651         return false;
 652 }
 653
 654 /**
 655  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 656  * if you need to edit part of a URL and put it back together.
 657  *
 658  * This is the basic structure used (brackets contain keys for $urlParts):
 659  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 660  *
 661  * @todo Need to integrate this into wfExpandUrl (see T34168)
 662  *
 663  * @since 1.19
 664  * @param array $urlParts URL parts, as output from wfParseUrl
 665  * @return string URL assembled from its component parts
 666  */
 667 function wfAssembleUrl( $urlParts ) {
 668         $result = '';
 669
 670         if ( isset( $urlParts['delimiter'] ) ) {
 671                 if ( isset( $urlParts['scheme'] ) ) {
 672                         $result .= $urlParts['scheme'];
 673                 }
 674
 675                 $result .= $urlParts['delimiter'];
 676         }
 677
 678         if ( isset( $urlParts['host'] ) ) {
 679                 if ( isset( $urlParts['user'] ) ) {
 680                         $result .= $urlParts['user'];
 681                         if ( isset( $urlParts['pass'] ) ) {
 682                                 $result .= ':' . $urlParts['pass'];
 683                         }
 684                         $result .= '@';
 685                 }
 686
 687                 $result .= $urlParts['host'];
 688
 689                 if ( isset( $urlParts['port'] ) ) {
 690                         $result .= ':' . $urlParts['port'];
 691                 }
 692         }
 693
 694         if ( isset( $urlParts['path'] ) ) {
 695                 $result .= $urlParts['path'];
 696         }
 697
 698         if ( isset( $urlParts['query'] ) ) {
 699                 $result .= '?' . $urlParts['query'];
 700         }
 701
 702         if ( isset( $urlParts['fragment'] ) ) {
 703                 $result .= '#' . $urlParts['fragment'];
 704         }
 705
 706         return $result;
 707 }
 708
 709 /**
 710  * Remove all dot-segments in the provided URL path.  For example,
 711  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 712  * RFC3986 section 5.2.4.
 713  *
 714  * @todo Need to integrate this into wfExpandUrl (see T34168)
 715  *
 716  * @param string $urlPath URL path, potentially containing dot-segments
 717  * @return string URL path with all dot-segments removed
 718  */
 719 function wfRemoveDotSegments( $urlPath ) {
 720         $output = '';
 721         $inputOffset = 0;
 722         $inputLength = strlen( $urlPath );
 723
 724         while ( $inputOffset < $inputLength ) {
 725                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 726                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 727                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 728                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 729                 $trimOutput = false;
 730
 731                 if ( $prefixLengthTwo == './' ) {
 732                         # Step A, remove leading "./"
 733                         $inputOffset += 2;
 734                 } elseif ( $prefixLengthThree == '../' ) {
 735                         # Step A, remove leading "../"
 736                         $inputOffset += 3;
 737                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 738                         # Step B, replace leading "/.$" with "/"
 739                         $inputOffset += 1;
 740                         $urlPath[$inputOffset] = '/';
 741                 } elseif ( $prefixLengthThree == '/./' ) {
 742                         # Step B, replace leading "/./" with "/"
 743                         $inputOffset += 2;
 744                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 745                         # Step C, replace leading "/..$" with "/" and
 746                         # remove last path component in output
 747                         $inputOffset += 2;
 748                         $urlPath[$inputOffset] = '/';
 749                         $trimOutput = true;
 750                 } elseif ( $prefixLengthFour == '/../' ) {
 751                         # Step C, replace leading "/../" with "/" and
 752                         # remove last path component in output
 753                         $inputOffset += 3;
 754                         $trimOutput = true;
 755                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 756                         # Step D, remove "^.$"
 757                         $inputOffset += 1;
 758                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 759                         # Step D, remove "^..$"
 760                         $inputOffset += 2;
 761                 } else {
 762                         # Step E, move leading path segment to output
 763                         if ( $prefixLengthOne == '/' ) {
 764                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 765                         } else {
 766                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 767                         }
 768                         if ( $slashPos === false ) {
 769                                 $output .= substr( $urlPath, $inputOffset );
 770                                 $inputOffset = $inputLength;
 771                         } else {
 772                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 773                                 $inputOffset += $slashPos - $inputOffset;
 774                         }
 775                 }
 776
 777                 if ( $trimOutput ) {
 778                         $slashPos = strrpos( $output, '/' );
 779                         if ( $slashPos === false ) {
 780                                 $output = '';
 781                         } else {
 782                                 $output = substr( $output, 0, $slashPos );
 783                         }
 784                 }
 785         }
 786
 787         return $output;
 788 }
 789
 790 /**
 791  * Returns a regular expression of url protocols
 792  *
 793  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 794  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 795  * @return string
 796  */
 797 function wfUrlProtocols( $includeProtocolRelative = true ) {
 798         global $wgUrlProtocols;
 799
 800         // Cache return values separately based on $includeProtocolRelative
 801         static $withProtRel = null, $withoutProtRel = null;
 802         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 803         if ( !is_null( $cachedValue ) ) {
 804                 return $cachedValue;
 805         }
 806
 807         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 808         // with LocalSettings files from 1.5
 809         if ( is_array( $wgUrlProtocols ) ) {
 810                 $protocols = [];
 811                 foreach ( $wgUrlProtocols as $protocol ) {
 812                         // Filter out '//' if !$includeProtocolRelative
 813                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 814                                 $protocols[] = preg_quote( $protocol, '/' );
 815                         }
 816                 }
 817
 818                 $retval = implode( '|', $protocols );
 819         } else {
 820                 // Ignore $includeProtocolRelative in this case
 821                 // This case exists for pre-1.6 compatibility, and we can safely assume
 822                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 823                 // URLs weren't supported until 1.18
 824                 $retval = $wgUrlProtocols;
 825         }
 826
 827         // Cache return value
 828         if ( $includeProtocolRelative ) {
 829                 $withProtRel = $retval;
 830         } else {
 831                 $withoutProtRel = $retval;
 832         }
 833         return $retval;
 834 }
 835
 836 /**
 837  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 838  * you need a regex that matches all URL protocols but does not match protocol-
 839  * relative URLs
 840  * @return string
 841  */
 842 function wfUrlProtocolsWithoutProtRel() {
 843         return wfUrlProtocols( false );
 844 }
 845
 846 /**
 847  * parse_url() work-alike, but non-broken.  Differences:
 848  *
 849  * 1) Does not raise warnings on bad URLs (just returns false).
 850  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 851  *    protocol-relative URLs) correctly.
 852  * 3) Adds a "delimiter" element to the array (see (2)).
 853  * 4) Verifies that the protocol is on the $wgUrlProtocols whitelist.
 854  * 5) Rejects some invalid URLs that parse_url doesn't, e.g. the empty string or URLs starting with
 855  *    a line feed character.
 856  *
 857  * @param string $url A URL to parse
 858  * @return string[]|bool Bits of the URL in an associative array, or false on failure.
 859  *   Possible fields:
 860  *   - scheme: URI scheme (protocol), e.g. 'http', 'mailto'. Lowercase, always present, but can
 861  *       be an empty string for protocol-relative URLs.
 862  *   - delimiter: either '://', ':' or '//'. Always present.
 863  *   - host: domain name / IP. Always present, but could be an empty string, e.g. for file: URLs.
 864  *   - user: user name, e.g. for HTTP Basic auth URLs such as http://user:pass@example.com/
 865  *       Missing when there is no username.
 866  *   - pass: password, same as above.
 867  *   - path: path including the leading /. Will be missing when empty (e.g. 'http://example.com')
 868  *   - query: query string (as a string; see wfCgiToArray() for parsing it), can be missing.
 869  *   - fragment: the part after #, can be missing.
 870  */
 871 function wfParseUrl( $url ) {
 872         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 873
 874         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 875         // bad that the easiest way to handle them is to just prepend 'http:' and
 876         // strip the protocol out later.
 877         $wasRelative = substr( $url, 0, 2 ) == '//';
 878         if ( $wasRelative ) {
 879                 $url = "http:$url";
 880         }
 881         MediaWiki\suppressWarnings();
 882         $bits = parse_url( $url );
 883         MediaWiki\restoreWarnings();
 884         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 885         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 886         if ( !$bits || !isset( $bits['scheme'] ) ) {
 887                 return false;
 888         }
 889
 890         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 891         $bits['scheme'] = strtolower( $bits['scheme'] );
 892
 893         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 894         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 895                 $bits['delimiter'] = '://';
 896         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 897                 $bits['delimiter'] = ':';
 898                 // parse_url detects for news: and mailto: the host part of an url as path
 899                 // We have to correct this wrong detection
 900                 if ( isset( $bits['path'] ) ) {
 901                         $bits['host'] = $bits['path'];
 902                         $bits['path'] = '';
 903                 }
 904         } else {
 905                 return false;
 906         }
 907
 908         /* Provide an empty host for eg. file:/// urls (see T30627) */
 909         if ( !isset( $bits['host'] ) ) {
 910                 $bits['host'] = '';
 911
 912                 // See T47069
 913                 if ( isset( $bits['path'] ) ) {
 914                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 915                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 916                                 $bits['path'] = '/' . $bits['path'];
 917                         }
 918                 } else {
 919                         $bits['path'] = '';
 920                 }
 921         }
 922
 923         // If the URL was protocol-relative, fix scheme and delimiter
 924         if ( $wasRelative ) {
 925                 $bits['scheme'] = '';
 926                 $bits['delimiter'] = '//';
 927         }
 928         return $bits;
 929 }
 930
 931 /**
 932  * Take a URL, make sure it's expanded to fully qualified, and replace any
 933  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 934  * for more compact display and legibility for local audiences.
 935  *
 936  * @todo handle punycode domains too
 937  *
 938  * @param string $url
 939  * @return string
 940  */
 941 function wfExpandIRI( $url ) {
 942         return preg_replace_callback(
 943                 '/((?:%[89A-F][0-9A-F])+)/i',
 944                 'wfExpandIRI_callback',
 945                 wfExpandUrl( $url )
 946         );
 947 }
 948
 949 /**
 950  * Private callback for wfExpandIRI
 951  * @param array $matches
 952  * @return string
 953  */
 954 function wfExpandIRI_callback( $matches ) {
 955         return urldecode( $matches[1] );
 956 }
 957
 958 /**
 959  * Make URL indexes, appropriate for the el_index field of externallinks.
 960  *
 961  * @param string $url
 962  * @return array
 963  */
 964 function wfMakeUrlIndexes( $url ) {
 965         $bits = wfParseUrl( $url );
 966
 967         // Reverse the labels in the hostname, convert to lower case
 968         // For emails reverse domainpart only
 969         if ( $bits['scheme'] == 'mailto' ) {
 970                 $mailparts = explode( '@', $bits['host'], 2 );
 971                 if ( count( $mailparts ) === 2 ) {
 972                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 973                 } else {
 974                         // No domain specified, don't mangle it
 975                         $domainpart = '';
 976                 }
 977                 $reversedHost = $domainpart . '@' . $mailparts[0];
 978         } else {
 979                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 980         }
 981         // Add an extra dot to the end
 982         // Why? Is it in wrong place in mailto links?
 983         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 984                 $reversedHost .= '.';
 985         }
 986         // Reconstruct the pseudo-URL
 987         $prot = $bits['scheme'];
 988         $index = $prot . $bits['delimiter'] . $reversedHost;
 989         // Leave out user and password. Add the port, path, query and fragment
 990         if ( isset( $bits['port'] ) ) {
 991                 $index .= ':' . $bits['port'];
 992         }
 993         if ( isset( $bits['path'] ) ) {
 994                 $index .= $bits['path'];
 995         } else {
 996                 $index .= '/';
 997         }
 998         if ( isset( $bits['query'] ) ) {
 999                 $index .= '?' . $bits['query'];
1000         }
1001         if ( isset( $bits['fragment'] ) ) {
1002                 $index .= '#' . $bits['fragment'];
1003         }
1004
1005         if ( $prot == '' ) {
1006                 return [ "http:$index", "https:$index" ];
1007         } else {
1008                 return [ $index ];
1009         }
1010 }
1011
1012 /**
1013  * Check whether a given URL has a domain that occurs in a given set of domains
1014  * @param string $url URL
1015  * @param array $domains Array of domains (strings)
1016  * @return bool True if the host part of $url ends in one of the strings in $domains
1017  */
1018 function wfMatchesDomainList( $url, $domains ) {
1019         $bits = wfParseUrl( $url );
1020         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1021                 $host = '.' . $bits['host'];
1022                 foreach ( (array)$domains as $domain ) {
1023                         $domain = '.' . $domain;
1024                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1025                                 return true;
1026                         }
1027                 }
1028         }
1029         return false;
1030 }
1031
1032 /**
1033  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1034  * In normal operation this is a NOP.
1035  *
1036  * Controlling globals:
1037  * $wgDebugLogFile - points to the log file
1038  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1039  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1040  *
1041  * @since 1.25 support for additional context data
1042  *
1043  * @param string $text
1044  * @param string|bool $dest Destination of the message:
1045  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1046  *     - 'private': excluded from HTML output
1047  *   For backward compatibility, it can also take a boolean:
1048  *     - true: same as 'all'
1049  *     - false: same as 'private'
1050  * @param array $context Additional logging context data
1051  */
1052 function wfDebug( $text, $dest = 'all', array $context = [] ) {
1053         global $wgDebugRawPage, $wgDebugLogPrefix;
1054         global $wgDebugTimestamps, $wgRequestTime;
1055
1056         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1057                 return;
1058         }
1059
1060         $text = trim( $text );
1061
1062         if ( $wgDebugTimestamps ) {
1063                 $context['seconds_elapsed'] = sprintf(
1064                         '%6.4f',
1065                         microtime( true ) - $wgRequestTime
1066                 );
1067                 $context['memory_used'] = sprintf(
1068                         '%5.1fM',
1069                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1070                 );
1071         }
1072
1073         if ( $wgDebugLogPrefix !== '' ) {
1074                 $context['prefix'] = $wgDebugLogPrefix;
1075         }
1076         $context['private'] = ( $dest === false || $dest === 'private' );
1077
1078         $logger = LoggerFactory::getInstance( 'wfDebug' );
1079         $logger->debug( $text, $context );
1080 }
1081
1082 /**
1083  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1084  * @return bool
1085  */
1086 function wfIsDebugRawPage() {
1087         static $cache;
1088         if ( $cache !== null ) {
1089                 return $cache;
1090         }
1091         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1092         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1093                 || (
1094                         isset( $_SERVER['SCRIPT_NAME'] )
1095                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1096                 )
1097         ) {
1098                 $cache = true;
1099         } else {
1100                 $cache = false;
1101         }
1102         return $cache;
1103 }
1104
1105 /**
1106  * Send a line giving PHP memory usage.
1107  *
1108  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1109  */
1110 function wfDebugMem( $exact = false ) {
1111         $mem = memory_get_usage();
1112         if ( !$exact ) {
1113                 $mem = floor( $mem / 1024 ) . ' KiB';
1114         } else {
1115                 $mem .= ' B';
1116         }
1117         wfDebug( "Memory usage: $mem\n" );
1118 }
1119
1120 /**
1121  * Send a line to a supplementary debug log file, if configured, or main debug
1122  * log if not.
1123  *
1124  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1125  * a string filename or an associative array mapping 'destination' to the
1126  * desired filename. The associative array may also contain a 'sample' key
1127  * with an integer value, specifying a sampling factor. Sampled log events
1128  * will be emitted with a 1 in N random chance.
1129  *
1130  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1131  * @since 1.25 support for additional context data
1132  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1133  *
1134  * @param string $logGroup
1135  * @param string $text
1136  * @param string|bool $dest Destination of the message:
1137  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1138  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1139  *       discarded otherwise
1140  *   For backward compatibility, it can also take a boolean:
1141  *     - true: same as 'all'
1142  *     - false: same as 'private'
1143  * @param array $context Additional logging context data
1144  */
1145 function wfDebugLog(
1146         $logGroup, $text, $dest = 'all', array $context = []
1147 ) {
1148         $text = trim( $text );
1149
1150         $logger = LoggerFactory::getInstance( $logGroup );
1151         $context['private'] = ( $dest === false || $dest === 'private' );
1152         $logger->info( $text, $context );
1153 }
1154
1155 /**
1156  * Log for database errors
1157  *
1158  * @since 1.25 support for additional context data
1159  *
1160  * @param string $text Database error message.
1161  * @param array $context Additional logging context data
1162  */
1163 function wfLogDBError( $text, array $context = [] ) {
1164         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1165         $logger->error( trim( $text ), $context );
1166 }
1167
1168 /**
1169  * Throws a warning that $function is deprecated
1170  *
1171  * @param string $function
1172  * @param string|bool $version Version of MediaWiki that the function
1173  *    was deprecated in (Added in 1.19).
1174  * @param string|bool $component Added in 1.19.
1175  * @param int $callerOffset How far up the call stack is the original
1176  *    caller. 2 = function that called the function that called
1177  *    wfDeprecated (Added in 1.20)
1178  *
1179  * @return null
1180  */
1181 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1182         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1183 }
1184
1185 /**
1186  * Send a warning either to the debug log or in a PHP error depending on
1187  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1188  *
1189  * @param string $msg Message to send
1190  * @param int $callerOffset Number of items to go back in the backtrace to
1191  *        find the correct caller (1 = function calling wfWarn, ...)
1192  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1193  *        only used when $wgDevelopmentWarnings is true
1194  */
1195 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1196         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1197 }
1198
1199 /**
1200  * Send a warning as a PHP error and the debug log. This is intended for logging
1201  * warnings in production. For logging development warnings, use WfWarn instead.
1202  *
1203  * @param string $msg Message to send
1204  * @param int $callerOffset Number of items to go back in the backtrace to
1205  *        find the correct caller (1 = function calling wfLogWarning, ...)
1206  * @param int $level PHP error level; defaults to E_USER_WARNING
1207  */
1208 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1209         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1210 }
1211
1212 /**
1213  * Log to a file without getting "file size exceeded" signals.
1214  *
1215  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1216  * send lines to the specified port, prefixed by the specified prefix and a space.
1217  * @since 1.25 support for additional context data
1218  *
1219  * @param string $text
1220  * @param string $file Filename
1221  * @param array $context Additional logging context data
1222  * @throws MWException
1223  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1224  */
1225 function wfErrorLog( $text, $file, array $context = [] ) {
1226         wfDeprecated( __METHOD__, '1.25' );
1227         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1228         $context['destination'] = $file;
1229         $logger->info( trim( $text ), $context );
1230 }
1231
1232 /**
1233  * @todo document
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         $config = $context->getConfig();
1246         $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1247         if ( $config->get( 'StatsdServer' ) && $stats->hasData() ) {
1248                 try {
1249                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1250                         $statsdHost = $statsdServer[0];
1251                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1252                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1253                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1254                         $statsdClient->setSamplingRates( $config->get( 'StatsdSamplingRates' ) );
1255                         $statsdClient->send( $stats->getData() );
1256                 } catch ( Exception $ex ) {
1257                         MWExceptionHandler::logException( $ex );
1258                 }
1259         }
1260
1261         # Profiling must actually be enabled...
1262         if ( $profiler instanceof ProfilerStub ) {
1263                 return;
1264         }
1265
1266         if ( isset( $wgDebugLogGroups['profileoutput'] )
1267                 && $wgDebugLogGroups['profileoutput'] === false
1268         ) {
1269                 // Explicitly disabled
1270                 return;
1271         }
1272         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1273                 return;
1274         }
1275
1276         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1277         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1278                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1279         }
1280         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1281                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1282         }
1283         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1284                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1285         }
1286         if ( isset( $ctx['forwarded_for'] ) ||
1287                 isset( $ctx['client_ip'] ) ||
1288                 isset( $ctx['from'] ) ) {
1289                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1290         }
1291
1292         // Don't load $wgUser at this late stage just for statistics purposes
1293         // @todo FIXME: We can detect some anons even if it is not loaded.
1294         // See User::getId()
1295         $user = $context->getUser();
1296         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1297
1298         // Command line script uses a FauxRequest object which does not have
1299         // any knowledge about an URL and throw an exception instead.
1300         try {
1301                 $ctx['url'] = urldecode( $request->getRequestURL() );
1302         } catch ( Exception $ignored ) {
1303                 // no-op
1304         }
1305
1306         $ctx['output'] = $profiler->getOutput();
1307
1308         $log = LoggerFactory::getInstance( 'profileoutput' );
1309         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1310 }
1311
1312 /**
1313  * Increment a statistics counter
1314  *
1315  * @param string $key
1316  * @param int $count
1317  * @return void
1318  */
1319 function wfIncrStats( $key, $count = 1 ) {
1320         $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1321         $stats->updateCount( $key, $count );
1322 }
1323
1324 /**
1325  * Check whether the wiki is in read-only mode.
1326  *
1327  * @return bool
1328  */
1329 function wfReadOnly() {
1330         return MediaWikiServices::getInstance()->getReadOnlyMode()
1331                 ->isReadOnly();
1332 }
1333
1334 /**
1335  * Check if the site is in read-only mode and return the message if so
1336  *
1337  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1338  * for replica DB lag. This may result in DB connection being made.
1339  *
1340  * @return string|bool String when in read-only mode; false otherwise
1341  */
1342 function wfReadOnlyReason() {
1343         return MediaWikiServices::getInstance()->getReadOnlyMode()
1344                 ->getReason();
1345 }
1346
1347 /**
1348  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1349  *
1350  * @return string|bool String when in read-only mode; false otherwise
1351  * @since 1.27
1352  */
1353 function wfConfiguredReadOnlyReason() {
1354         return MediaWikiServices::getInstance()->getConfiguredReadOnlyMode()
1355                 ->getReason();
1356 }
1357
1358 /**
1359  * Return a Language object from $langcode
1360  *
1361  * @param Language|string|bool $langcode Either:
1362  *                  - a Language object
1363  *                  - code of the language to get the message for, if it is
1364  *                    a valid code create a language for that language, if
1365  *                    it is a string but not a valid code then make a basic
1366  *                    language object
1367  *                  - a boolean: if it's false then use the global object for
1368  *                    the current user's language (as a fallback for the old parameter
1369  *                    functionality), or if it is true then use global object
1370  *                    for the wiki's content language.
1371  * @return Language
1372  */
1373 function wfGetLangObj( $langcode = false ) {
1374         # Identify which language to get or create a language object for.
1375         # Using is_object here due to Stub objects.
1376         if ( is_object( $langcode ) ) {
1377                 # Great, we already have the object (hopefully)!
1378                 return $langcode;
1379         }
1380
1381         global $wgContLang, $wgLanguageCode;
1382         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1383                 # $langcode is the language code of the wikis content language object.
1384                 # or it is a boolean and value is true
1385                 return $wgContLang;
1386         }
1387
1388         global $wgLang;
1389         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1390                 # $langcode is the language code of user language object.
1391                 # or it was a boolean and value is false
1392                 return $wgLang;
1393         }
1394
1395         $validCodes = array_keys( Language::fetchLanguageNames() );
1396         if ( in_array( $langcode, $validCodes ) ) {
1397                 # $langcode corresponds to a valid language.
1398                 return Language::factory( $langcode );
1399         }
1400
1401         # $langcode is a string, but not a valid language code; use content language.
1402         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1403         return $wgContLang;
1404 }
1405
1406 /**
1407  * This is the function for getting translated interface messages.
1408  *
1409  * @see Message class for documentation how to use them.
1410  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1411  *
1412  * This function replaces all old wfMsg* functions.
1413  *
1414  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1415  * @param mixed $params,... Normal message parameters
1416  * @return Message
1417  *
1418  * @since 1.17
1419  *
1420  * @see Message::__construct
1421  */
1422 function wfMessage( $key /*...*/ ) {
1423         $message = new Message( $key );
1424
1425         // We call Message::params() to reduce code duplication
1426         $params = func_get_args();
1427         array_shift( $params );
1428         if ( $params ) {
1429                 call_user_func_array( [ $message, 'params' ], $params );
1430         }
1431
1432         return $message;
1433 }
1434
1435 /**
1436  * This function accepts multiple message keys and returns a message instance
1437  * for the first message which is non-empty. If all messages are empty then an
1438  * instance of the first message key is returned.
1439  *
1440  * @param string|string[] $keys,... Message keys
1441  * @return Message
1442  *
1443  * @since 1.18
1444  *
1445  * @see Message::newFallbackSequence
1446  */
1447 function wfMessageFallback( /*...*/ ) {
1448         $args = func_get_args();
1449         return call_user_func_array( 'Message::newFallbackSequence', $args );
1450 }
1451
1452 /**
1453  * Replace message parameter keys on the given formatted output.
1454  *
1455  * @param string $message
1456  * @param array $args
1457  * @return string
1458  * @private
1459  */
1460 function wfMsgReplaceArgs( $message, $args ) {
1461         # Fix windows line-endings
1462         # Some messages are split with explode("\n", $msg)
1463         $message = str_replace( "\r", '', $message );
1464
1465         // Replace arguments
1466         if ( is_array( $args ) && $args ) {
1467                 if ( is_array( $args[0] ) ) {
1468                         $args = array_values( $args[0] );
1469                 }
1470                 $replacementKeys = [];
1471                 foreach ( $args as $n => $param ) {
1472                         $replacementKeys['$' . ( $n + 1 )] = $param;
1473                 }
1474                 $message = strtr( $message, $replacementKeys );
1475         }
1476
1477         return $message;
1478 }
1479
1480 /**
1481  * Fetch server name for use in error reporting etc.
1482  * Use real server name if available, so we know which machine
1483  * in a server farm generated the current page.
1484  *
1485  * @return string
1486  */
1487 function wfHostname() {
1488         static $host;
1489         if ( is_null( $host ) ) {
1490                 # Hostname overriding
1491                 global $wgOverrideHostname;
1492                 if ( $wgOverrideHostname !== false ) {
1493                         # Set static and skip any detection
1494                         $host = $wgOverrideHostname;
1495                         return $host;
1496                 }
1497
1498                 if ( function_exists( 'posix_uname' ) ) {
1499                         // This function not present on Windows
1500                         $uname = posix_uname();
1501                 } else {
1502                         $uname = false;
1503                 }
1504                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1505                         $host = $uname['nodename'];
1506                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1507                         # Windows computer name
1508                         $host = getenv( 'COMPUTERNAME' );
1509                 } else {
1510                         # This may be a virtual server.
1511                         $host = $_SERVER['SERVER_NAME'];
1512                 }
1513         }
1514         return $host;
1515 }
1516
1517 /**
1518  * Returns a script tag that stores the amount of time it took MediaWiki to
1519  * handle the request in milliseconds as 'wgBackendResponseTime'.
1520  *
1521  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1522  * hostname of the server handling the request.
1523  *
1524  * @return string
1525  */
1526 function wfReportTime() {
1527         global $wgRequestTime, $wgShowHostnames;
1528
1529         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1530         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1531         if ( $wgShowHostnames ) {
1532                 $reportVars['wgHostname'] = wfHostname();
1533         }
1534         return Skin::makeVariablesScript( $reportVars );
1535 }
1536
1537 /**
1538  * Safety wrapper for debug_backtrace().
1539  *
1540  * Will return an empty array if debug_backtrace is disabled, otherwise
1541  * the output from debug_backtrace() (trimmed).
1542  *
1543  * @param int $limit This parameter can be used to limit the number of stack frames returned
1544  *
1545  * @return array Array of backtrace information
1546  */
1547 function wfDebugBacktrace( $limit = 0 ) {
1548         static $disabled = null;
1549
1550         if ( is_null( $disabled ) ) {
1551                 $disabled = !function_exists( 'debug_backtrace' );
1552                 if ( $disabled ) {
1553                         wfDebug( "debug_backtrace() is disabled\n" );
1554                 }
1555         }
1556         if ( $disabled ) {
1557                 return [];
1558         }
1559
1560         if ( $limit ) {
1561                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1562         } else {
1563                 return array_slice( debug_backtrace(), 1 );
1564         }
1565 }
1566
1567 /**
1568  * Get a debug backtrace as a string
1569  *
1570  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1571  *   Defaults to $wgCommandLineMode if unset.
1572  * @return string
1573  * @since 1.25 Supports $raw parameter.
1574  */
1575 function wfBacktrace( $raw = null ) {
1576         global $wgCommandLineMode;
1577
1578         if ( $raw === null ) {
1579                 $raw = $wgCommandLineMode;
1580         }
1581
1582         if ( $raw ) {
1583                 $frameFormat = "%s line %s calls %s()\n";
1584                 $traceFormat = "%s";
1585         } else {
1586                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1587                 $traceFormat = "<ul>\n%s</ul>\n";
1588         }
1589
1590         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1591                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1592                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1593                 $call = $frame['function'];
1594                 if ( !empty( $frame['class'] ) ) {
1595                         $call = $frame['class'] . $frame['type'] . $call;
1596                 }
1597                 return sprintf( $frameFormat, $file, $line, $call );
1598         }, wfDebugBacktrace() );
1599
1600         return sprintf( $traceFormat, implode( '', $frames ) );
1601 }
1602
1603 /**
1604  * Get the name of the function which called this function
1605  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1606  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1607  * wfGetCaller( 3 ) is the parent of that.
1608  *
1609  * @param int $level
1610  * @return string
1611  */
1612 function wfGetCaller( $level = 2 ) {
1613         $backtrace = wfDebugBacktrace( $level + 1 );
1614         if ( isset( $backtrace[$level] ) ) {
1615                 return wfFormatStackFrame( $backtrace[$level] );
1616         } else {
1617                 return 'unknown';
1618         }
1619 }
1620
1621 /**
1622  * Return a string consisting of callers in the stack. Useful sometimes
1623  * for profiling specific points.
1624  *
1625  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1626  * @return string
1627  */
1628 function wfGetAllCallers( $limit = 3 ) {
1629         $trace = array_reverse( wfDebugBacktrace() );
1630         if ( !$limit || $limit > count( $trace ) - 1 ) {
1631                 $limit = count( $trace ) - 1;
1632         }
1633         $trace = array_slice( $trace, -$limit - 1, $limit );
1634         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1635 }
1636
1637 /**
1638  * Return a string representation of frame
1639  *
1640  * @param array $frame
1641  * @return string
1642  */
1643 function wfFormatStackFrame( $frame ) {
1644         if ( !isset( $frame['function'] ) ) {
1645                 return 'NO_FUNCTION_GIVEN';
1646         }
1647         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1648                 $frame['class'] . $frame['type'] . $frame['function'] :
1649                 $frame['function'];
1650 }
1651
1652 /* Some generic result counters, pulled out of SearchEngine */
1653
1654 /**
1655  * @todo document
1656  *
1657  * @param int $offset
1658  * @param int $limit
1659  * @return string
1660  */
1661 function wfShowingResults( $offset, $limit ) {
1662         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1663 }
1664
1665 /**
1666  * Whether the client accept gzip encoding
1667  *
1668  * Uses the Accept-Encoding header to check if the client supports gzip encoding.
1669  * Use this when considering to send a gzip-encoded response to the client.
1670  *
1671  * @param bool $force Forces another check even if we already have a cached result.
1672  * @return bool
1673  */
1674 function wfClientAcceptsGzip( $force = false ) {
1675         static $result = null;
1676         if ( $result === null || $force ) {
1677                 $result = false;
1678                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1679                         # @todo FIXME: We may want to blacklist some broken browsers
1680                         $m = [];
1681                         if ( preg_match(
1682                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1683                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1684                                         $m
1685                                 )
1686                         ) {
1687                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1688                                         $result = false;
1689                                         return $result;
1690                                 }
1691                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1692                                 $result = true;
1693                         }
1694                 }
1695         }
1696         return $result;
1697 }
1698
1699 /**
1700  * Escapes the given text so that it may be output using addWikiText()
1701  * without any linking, formatting, etc. making its way through. This
1702  * is achieved by substituting certain characters with HTML entities.
1703  * As required by the callers, "<nowiki>" is not used.
1704  *
1705  * @param string $text Text to be escaped
1706  * @return string
1707  */
1708 function wfEscapeWikiText( $text ) {
1709         global $wgEnableMagicLinks;
1710         static $repl = null, $repl2 = null;
1711         if ( $repl === null || defined( 'MW_PARSER_TEST' ) || defined( 'MW_PHPUNIT_TEST' ) ) {
1712                 // Tests depend upon being able to change $wgEnableMagicLinks, so don't cache
1713                 // in those situations
1714                 $repl = [
1715                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1716                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1717                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1718                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1719                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1720                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1721                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1722                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1723                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1724                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1725                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1726                         '__' => '_&#95;', '://' => '&#58;//',
1727                 ];
1728
1729                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1730                 // We have to catch everything "\s" matches in PCRE
1731                 foreach ( $magicLinks as $magic ) {
1732                         $repl["$magic "] = "$magic&#32;";
1733                         $repl["$magic\t"] = "$magic&#9;";
1734                         $repl["$magic\r"] = "$magic&#13;";
1735                         $repl["$magic\n"] = "$magic&#10;";
1736                         $repl["$magic\f"] = "$magic&#12;";
1737                 }
1738
1739                 // And handle protocols that don't use "://"
1740                 global $wgUrlProtocols;
1741                 $repl2 = [];
1742                 foreach ( $wgUrlProtocols as $prot ) {
1743                         if ( substr( $prot, -1 ) === ':' ) {
1744                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1745                         }
1746                 }
1747                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1748         }
1749         $text = substr( strtr( "\n$text", $repl ), 1 );
1750         $text = preg_replace( $repl2, '$1&#58;', $text );
1751         return $text;
1752 }
1753
1754 /**
1755  * Sets dest to source and returns the original value of dest
1756  * If source is NULL, it just returns the value, it doesn't set the variable
1757  * If force is true, it will set the value even if source is NULL
1758  *
1759  * @param mixed &$dest
1760  * @param mixed $source
1761  * @param bool $force
1762  * @return mixed
1763  */
1764 function wfSetVar( &$dest, $source, $force = false ) {
1765         $temp = $dest;
1766         if ( !is_null( $source ) || $force ) {
1767                 $dest = $source;
1768         }
1769         return $temp;
1770 }
1771
1772 /**
1773  * As for wfSetVar except setting a bit
1774  *
1775  * @param int &$dest
1776  * @param int $bit
1777  * @param bool $state
1778  *
1779  * @return bool
1780  */
1781 function wfSetBit( &$dest, $bit, $state = true ) {
1782         $temp = (bool)( $dest & $bit );
1783         if ( !is_null( $state ) ) {
1784                 if ( $state ) {
1785                         $dest |= $bit;
1786                 } else {
1787                         $dest &= ~$bit;
1788                 }
1789         }
1790         return $temp;
1791 }
1792
1793 /**
1794  * A wrapper around the PHP function var_export().
1795  * Either print it or add it to the regular output ($wgOut).
1796  *
1797  * @param mixed $var A PHP variable to dump.
1798  */
1799 function wfVarDump( $var ) {
1800         global $wgOut;
1801         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1802         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1803                 print $s;
1804         } else {
1805                 $wgOut->addHTML( $s );
1806         }
1807 }
1808
1809 /**
1810  * Provide a simple HTTP error.
1811  *
1812  * @param int|string $code
1813  * @param string $label
1814  * @param string $desc
1815  */
1816 function wfHttpError( $code, $label, $desc ) {
1817         global $wgOut;
1818         HttpStatus::header( $code );
1819         if ( $wgOut ) {
1820                 $wgOut->disable();
1821                 $wgOut->sendCacheControl();
1822         }
1823
1824         MediaWiki\HeaderCallback::warnIfHeadersSent();
1825         header( 'Content-type: text/html; charset=utf-8' );
1826         print '<!DOCTYPE html>' .
1827                 '<html><head><title>' .
1828                 htmlspecialchars( $label ) .
1829                 '</title></head><body><h1>' .
1830                 htmlspecialchars( $label ) .
1831                 '</h1><p>' .
1832                 nl2br( htmlspecialchars( $desc ) ) .
1833                 "</p></body></html>\n";
1834 }
1835
1836 /**
1837  * Clear away any user-level output buffers, discarding contents.
1838  *
1839  * Suitable for 'starting afresh', for instance when streaming
1840  * relatively large amounts of data without buffering, or wanting to
1841  * output image files without ob_gzhandler's compression.
1842  *
1843  * The optional $resetGzipEncoding parameter controls suppression of
1844  * the Content-Encoding header sent by ob_gzhandler; by default it
1845  * is left. See comments for wfClearOutputBuffers() for why it would
1846  * be used.
1847  *
1848  * Note that some PHP configuration options may add output buffer
1849  * layers which cannot be removed; these are left in place.
1850  *
1851  * @param bool $resetGzipEncoding
1852  */
1853 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1854         if ( $resetGzipEncoding ) {
1855                 // Suppress Content-Encoding and Content-Length
1856                 // headers from 1.10+s wfOutputHandler
1857                 global $wgDisableOutputCompression;
1858                 $wgDisableOutputCompression = true;
1859         }
1860         while ( $status = ob_get_status() ) {
1861                 if ( isset( $status['flags'] ) ) {
1862                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1863                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1864                 } elseif ( isset( $status['del'] ) ) {
1865                         $deleteable = $status['del'];
1866                 } else {
1867                         // Guess that any PHP-internal setting can't be removed.
1868                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1869                 }
1870                 if ( !$deleteable ) {
1871                         // Give up, and hope the result doesn't break
1872                         // output behavior.
1873                         break;
1874                 }
1875                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1876                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1877                         break;
1878                 }
1879                 if ( !ob_end_clean() ) {
1880                         // Could not remove output buffer handler; abort now
1881                         // to avoid getting in some kind of infinite loop.
1882                         break;
1883                 }
1884                 if ( $resetGzipEncoding ) {
1885                         if ( $status['name'] == 'ob_gzhandler' ) {
1886                                 // Reset the 'Content-Encoding' field set by this handler
1887                                 // so we can start fresh.
1888                                 header_remove( 'Content-Encoding' );
1889                                 break;
1890                         }
1891                 }
1892         }
1893 }
1894
1895 /**
1896  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1897  *
1898  * Clear away output buffers, but keep the Content-Encoding header
1899  * produced by ob_gzhandler, if any.
1900  *
1901  * This should be used for HTTP 304 responses, where you need to
1902  * preserve the Content-Encoding header of the real result, but
1903  * also need to suppress the output of ob_gzhandler to keep to spec
1904  * and avoid breaking Firefox in rare cases where the headers and
1905  * body are broken over two packets.
1906  */
1907 function wfClearOutputBuffers() {
1908         wfResetOutputBuffers( false );
1909 }
1910
1911 /**
1912  * Converts an Accept-* header into an array mapping string values to quality
1913  * factors
1914  *
1915  * @param string $accept
1916  * @param string $def Default
1917  * @return float[] Associative array of string => float pairs
1918  */
1919 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1920         # No arg means accept anything (per HTTP spec)
1921         if ( !$accept ) {
1922                 return [ $def => 1.0 ];
1923         }
1924
1925         $prefs = [];
1926
1927         $parts = explode( ',', $accept );
1928
1929         foreach ( $parts as $part ) {
1930                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1931                 $values = explode( ';', trim( $part ) );
1932                 $match = [];
1933                 if ( count( $values ) == 1 ) {
1934                         $prefs[$values[0]] = 1.0;
1935                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1936                         $prefs[$values[0]] = floatval( $match[1] );
1937                 }
1938         }
1939
1940         return $prefs;
1941 }
1942
1943 /**
1944  * Checks if a given MIME type matches any of the keys in the given
1945  * array. Basic wildcards are accepted in the array keys.
1946  *
1947  * Returns the matching MIME type (or wildcard) if a match, otherwise
1948  * NULL if no match.
1949  *
1950  * @param string $type
1951  * @param array $avail
1952  * @return string
1953  * @private
1954  */
1955 function mimeTypeMatch( $type, $avail ) {
1956         if ( array_key_exists( $type, $avail ) ) {
1957                 return $type;
1958         } else {
1959                 $mainType = explode( '/', $type )[0];
1960                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1961                         return "$mainType/*";
1962                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1963                         return '*/*';
1964                 } else {
1965                         return null;
1966                 }
1967         }
1968 }
1969
1970 /**
1971  * Returns the 'best' match between a client's requested internet media types
1972  * and the server's list of available types. Each list should be an associative
1973  * array of type to preference (preference is a float between 0.0 and 1.0).
1974  * Wildcards in the types are acceptable.
1975  *
1976  * @param array $cprefs Client's acceptable type list
1977  * @param array $sprefs Server's offered types
1978  * @return string
1979  *
1980  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1981  * XXX: generalize to negotiate other stuff
1982  */
1983 function wfNegotiateType( $cprefs, $sprefs ) {
1984         $combine = [];
1985
1986         foreach ( array_keys( $sprefs ) as $type ) {
1987                 $subType = explode( '/', $type )[1];
1988                 if ( $subType != '*' ) {
1989                         $ckey = mimeTypeMatch( $type, $cprefs );
1990                         if ( $ckey ) {
1991                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1992                         }
1993                 }
1994         }
1995
1996         foreach ( array_keys( $cprefs ) as $type ) {
1997                 $subType = explode( '/', $type )[1];
1998                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1999                         $skey = mimeTypeMatch( $type, $sprefs );
2000                         if ( $skey ) {
2001                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2002                         }
2003                 }
2004         }
2005
2006         $bestq = 0;
2007         $besttype = null;
2008
2009         foreach ( array_keys( $combine ) as $type ) {
2010                 if ( $combine[$type] > $bestq ) {
2011                         $besttype = $type;
2012                         $bestq = $combine[$type];
2013                 }
2014         }
2015
2016         return $besttype;
2017 }
2018
2019 /**
2020  * Reference-counted warning suppression
2021  *
2022  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
2023  * @param bool $end
2024  */
2025 function wfSuppressWarnings( $end = false ) {
2026         MediaWiki\suppressWarnings( $end );
2027 }
2028
2029 /**
2030  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
2031  * Restore error level to previous value
2032  */
2033 function wfRestoreWarnings() {
2034         MediaWiki\suppressWarnings( true );
2035 }
2036
2037 /**
2038  * Get a timestamp string in one of various formats
2039  *
2040  * @param mixed $outputtype A timestamp in one of the supported formats, the
2041  *   function will autodetect which format is supplied and act accordingly.
2042  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2043  * @return string|bool String / false The same date in the format specified in $outputtype or false
2044  */
2045 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2046         $ret = MWTimestamp::convert( $outputtype, $ts );
2047         if ( $ret === false ) {
2048                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2049         }
2050         return $ret;
2051 }
2052
2053 /**
2054  * Return a formatted timestamp, or null if input is null.
2055  * For dealing with nullable timestamp columns in the database.
2056  *
2057  * @param int $outputtype
2058  * @param string $ts
2059  * @return string
2060  */
2061 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2062         if ( is_null( $ts ) ) {
2063                 return null;
2064         } else {
2065                 return wfTimestamp( $outputtype, $ts );
2066         }
2067 }
2068
2069 /**
2070  * Convenience function; returns MediaWiki timestamp for the present time.
2071  *
2072  * @return string
2073  */
2074 function wfTimestampNow() {
2075         # return NOW
2076         return MWTimestamp::now( TS_MW );
2077 }
2078
2079 /**
2080  * Check if the operating system is Windows
2081  *
2082  * @return bool True if it's Windows, false otherwise.
2083  */
2084 function wfIsWindows() {
2085         static $isWindows = null;
2086         if ( $isWindows === null ) {
2087                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2088         }
2089         return $isWindows;
2090 }
2091
2092 /**
2093  * Check if we are running under HHVM
2094  *
2095  * @return bool
2096  */
2097 function wfIsHHVM() {
2098         return defined( 'HHVM_VERSION' );
2099 }
2100
2101 /**
2102  * Tries to get the system directory for temporary files. First
2103  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2104  * environment variables are then checked in sequence, then
2105  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2106  *
2107  * NOTE: When possible, use instead the tmpfile() function to create
2108  * temporary files to avoid race conditions on file creation, etc.
2109  *
2110  * @return string
2111  */
2112 function wfTempDir() {
2113         global $wgTmpDirectory;
2114
2115         if ( $wgTmpDirectory !== false ) {
2116                 return $wgTmpDirectory;
2117         }
2118
2119         return TempFSFile::getUsableTempDirectory();
2120 }
2121
2122 /**
2123  * Make directory, and make all parent directories if they don't exist
2124  *
2125  * @param string $dir Full path to directory to create
2126  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2127  * @param string $caller Optional caller param for debugging.
2128  * @throws MWException
2129  * @return bool
2130  */
2131 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2132         global $wgDirectoryMode;
2133
2134         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2135                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2136         }
2137
2138         if ( !is_null( $caller ) ) {
2139                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2140         }
2141
2142         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2143                 return true;
2144         }
2145
2146         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
2147
2148         if ( is_null( $mode ) ) {
2149                 $mode = $wgDirectoryMode;
2150         }
2151
2152         // Turn off the normal warning, we're doing our own below
2153         MediaWiki\suppressWarnings();
2154         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2155         MediaWiki\restoreWarnings();
2156
2157         if ( !$ok ) {
2158                 // directory may have been created on another request since we last checked
2159                 if ( is_dir( $dir ) ) {
2160                         return true;
2161                 }
2162
2163                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2164                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2165         }
2166         return $ok;
2167 }
2168
2169 /**
2170  * Remove a directory and all its content.
2171  * Does not hide error.
2172  * @param string $dir
2173  */
2174 function wfRecursiveRemoveDir( $dir ) {
2175         wfDebug( __FUNCTION__ . "( $dir )\n" );
2176         // taken from https://secure.php.net/manual/en/function.rmdir.php#98622
2177         if ( is_dir( $dir ) ) {
2178                 $objects = scandir( $dir );
2179                 foreach ( $objects as $object ) {
2180                         if ( $object != "." && $object != ".." ) {
2181                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2182                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2183                                 } else {
2184                                         unlink( $dir . '/' . $object );
2185                                 }
2186                         }
2187                 }
2188                 reset( $objects );
2189                 rmdir( $dir );
2190         }
2191 }
2192
2193 /**
2194  * @param int $nr The number to format
2195  * @param int $acc The number of digits after the decimal point, default 2
2196  * @param bool $round Whether or not to round the value, default true
2197  * @return string
2198  */
2199 function wfPercent( $nr, $acc = 2, $round = true ) {
2200         $ret = sprintf( "%.${acc}f", $nr );
2201         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2202 }
2203
2204 /**
2205  * Safety wrapper around ini_get() for boolean settings.
2206  * The values returned from ini_get() are pre-normalized for settings
2207  * set via php.ini or php_flag/php_admin_flag... but *not*
2208  * for those set via php_value/php_admin_value.
2209  *
2210  * It's fairly common for people to use php_value instead of php_flag,
2211  * which can leave you with an 'off' setting giving a false positive
2212  * for code that just takes the ini_get() return value as a boolean.
2213  *
2214  * To make things extra interesting, setting via php_value accepts
2215  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2216  * Unrecognized values go false... again opposite PHP's own coercion
2217  * from string to bool.
2218  *
2219  * Luckily, 'properly' set settings will always come back as '0' or '1',
2220  * so we only have to worry about them and the 'improper' settings.
2221  *
2222  * I frickin' hate PHP... :P
2223  *
2224  * @param string $setting
2225  * @return bool
2226  */
2227 function wfIniGetBool( $setting ) {
2228         return wfStringToBool( ini_get( $setting ) );
2229 }
2230
2231 /**
2232  * Convert string value to boolean, when the following are interpreted as true:
2233  * - on
2234  * - true
2235  * - yes
2236  * - Any number, except 0
2237  * All other strings are interpreted as false.
2238  *
2239  * @param string $val
2240  * @return bool
2241  * @since 1.31
2242  */
2243 function wfStringToBool( $val ) {
2244         $val = strtolower( $val );
2245         // 'on' and 'true' can't have whitespace around them, but '1' can.
2246         return $val == 'on'
2247                 || $val == 'true'
2248                 || $val == 'yes'
2249                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2250 }
2251
2252 /**
2253  * Version of escapeshellarg() that works better on Windows.
2254  *
2255  * Originally, this fixed the incorrect use of single quotes on Windows
2256  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2257  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2258  *
2259  * @param string $args,... strings to escape and glue together,
2260  *  or a single array of strings parameter
2261  * @return string
2262  * @deprecated since 1.30 use MediaWiki\Shell::escape()
2263  */
2264 function wfEscapeShellArg( /*...*/ ) {
2265         $args = func_get_args();
2266
2267         return call_user_func_array( Shell::class . '::escape', $args );
2268 }
2269
2270 /**
2271  * Check if wfShellExec() is effectively disabled via php.ini config
2272  *
2273  * @return bool|string False or 'disabled'
2274  * @since 1.22
2275  * @deprecated since 1.30 use MediaWiki\Shell::isDisabled()
2276  */
2277 function wfShellExecDisabled() {
2278         wfDeprecated( __FUNCTION__, '1.30' );
2279         return Shell::isDisabled() ? 'disabled' : false;
2280 }
2281
2282 /**
2283  * Execute a shell command, with time and memory limits mirrored from the PHP
2284  * configuration if supported.
2285  *
2286  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2287  *   or an array of unescaped arguments, in which case each value will be escaped
2288  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2289  * @param null|mixed &$retval Optional, will receive the program's exit code.
2290  *   (non-zero is usually failure). If there is an error from
2291  *   read, select, or proc_open(), this will be set to -1.
2292  * @param array $environ Optional environment variables which should be
2293  *   added to the executed command environment.
2294  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2295  *   this overwrites the global wgMaxShell* limits.
2296  * @param array $options Array of options:
2297  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2298  *     including errors from limit.sh
2299  *   - profileMethod: By default this function will profile based on the calling
2300  *     method. Set this to a string for an alternative method to profile from
2301  *
2302  * @return string Collected stdout as a string
2303  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2304  */
2305 function wfShellExec( $cmd, &$retval = null, $environ = [],
2306         $limits = [], $options = []
2307 ) {
2308         if ( Shell::isDisabled() ) {
2309                 $retval = 1;
2310                 // Backwards compatibility be upon us...
2311                 return 'Unable to run external programs, proc_open() is disabled.';
2312         }
2313
2314         if ( is_array( $cmd ) ) {
2315                 $cmd = Shell::escape( $cmd );
2316         }
2317
2318         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2319         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2320
2321         try {
2322                 $result = Shell::command( [] )
2323                         ->unsafeParams( (array)$cmd )
2324                         ->environment( $environ )
2325                         ->limits( $limits )
2326                         ->includeStderr( $includeStderr )
2327                         ->profileMethod( $profileMethod )
2328                         ->execute();
2329         } catch ( ProcOpenError $ex ) {
2330                 $retval = -1;
2331                 return '';
2332         }
2333
2334         $retval = $result->getExitCode();
2335
2336         return $result->getStdout();
2337 }
2338
2339 /**
2340  * Execute a shell command, returning both stdout and stderr. Convenience
2341  * function, as all the arguments to wfShellExec can become unwieldy.
2342  *
2343  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2344  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2345  *   or an array of unescaped arguments, in which case each value will be escaped
2346  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2347  * @param null|mixed &$retval Optional, will receive the program's exit code.
2348  *   (non-zero is usually failure)
2349  * @param array $environ Optional environment variables which should be
2350  *   added to the executed command environment.
2351  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2352  *   this overwrites the global wgMaxShell* limits.
2353  * @return string Collected stdout and stderr as a string
2354  * @deprecated since 1.30 use class MediaWiki\Shell\Shell
2355  */
2356 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2357         return wfShellExec( $cmd, $retval, $environ, $limits,
2358                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2359 }
2360
2361 /**
2362  * Formerly set the locale for locale-sensitive operations
2363  *
2364  * This is now done in Setup.php.
2365  *
2366  * @deprecated since 1.30, no longer needed
2367  * @see $wgShellLocale
2368  */
2369 function wfInitShellLocale() {
2370         wfDeprecated( __FUNCTION__, '1.30' );
2371 }
2372
2373 /**
2374  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2375  * Note that $parameters should be a flat array and an option with an argument
2376  * should consist of two consecutive items in the array (do not use "--option value").
2377  *
2378  * @param string $script MediaWiki cli script path
2379  * @param array $parameters Arguments and options to the script
2380  * @param array $options Associative array of options:
2381  *     'php': The path to the php executable
2382  *     'wrapper': Path to a PHP wrapper to handle the maintenance script
2383  * @return string
2384  */
2385 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2386         global $wgPhpCli;
2387         // Give site config file a chance to run the script in a wrapper.
2388         // The caller may likely want to call wfBasename() on $script.
2389         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2390         $cmd = isset( $options['php'] ) ? [ $options['php'] ] : [ $wgPhpCli ];
2391         if ( isset( $options['wrapper'] ) ) {
2392                 $cmd[] = $options['wrapper'];
2393         }
2394         $cmd[] = $script;
2395         // Escape each parameter for shell
2396         return Shell::escape( array_merge( $cmd, $parameters ) );
2397 }
2398
2399 /**
2400  * wfMerge attempts to merge differences between three texts.
2401  * Returns true for a clean merge and false for failure or a conflict.
2402  *
2403  * @param string $old
2404  * @param string $mine
2405  * @param string $yours
2406  * @param string &$result
2407  * @return bool
2408  */
2409 function wfMerge( $old, $mine, $yours, &$result ) {
2410         global $wgDiff3;
2411
2412         # This check may also protect against code injection in
2413         # case of broken installations.
2414         MediaWiki\suppressWarnings();
2415         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2416         MediaWiki\restoreWarnings();
2417
2418         if ( !$haveDiff3 ) {
2419                 wfDebug( "diff3 not found\n" );
2420                 return false;
2421         }
2422
2423         # Make temporary files
2424         $td = wfTempDir();
2425         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2426         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2427         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2428
2429         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2430         #       a newline character. To avoid this, we normalize the trailing whitespace before
2431         #       creating the diff.
2432
2433         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2434         fclose( $oldtextFile );
2435         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2436         fclose( $mytextFile );
2437         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2438         fclose( $yourtextFile );
2439
2440         # Check for a conflict
2441         $cmd = Shell::escape( $wgDiff3, '-a', '--overlap-only', $mytextName,
2442                 $oldtextName, $yourtextName );
2443         $handle = popen( $cmd, 'r' );
2444
2445         if ( fgets( $handle, 1024 ) ) {
2446                 $conflict = true;
2447         } else {
2448                 $conflict = false;
2449         }
2450         pclose( $handle );
2451
2452         # Merge differences
2453         $cmd = Shell::escape( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2454                 $oldtextName, $yourtextName );
2455         $handle = popen( $cmd, 'r' );
2456         $result = '';
2457         do {
2458                 $data = fread( $handle, 8192 );
2459                 if ( strlen( $data ) == 0 ) {
2460                         break;
2461                 }
2462                 $result .= $data;
2463         } while ( true );
2464         pclose( $handle );
2465         unlink( $mytextName );
2466         unlink( $oldtextName );
2467         unlink( $yourtextName );
2468
2469         if ( $result === '' && $old !== '' && !$conflict ) {
2470                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2471                 $conflict = true;
2472         }
2473         return !$conflict;
2474 }
2475
2476 /**
2477  * Returns unified plain-text diff of two texts.
2478  * "Useful" for machine processing of diffs.
2479  *
2480  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2481  *
2482  * @param string $before The text before the changes.
2483  * @param string $after The text after the changes.
2484  * @param string $params Command-line options for the diff command.
2485  * @return string Unified diff of $before and $after
2486  */
2487 function wfDiff( $before, $after, $params = '-u' ) {
2488         if ( $before == $after ) {
2489                 return '';
2490         }
2491
2492         global $wgDiff;
2493         MediaWiki\suppressWarnings();
2494         $haveDiff = $wgDiff && file_exists( $wgDiff );
2495         MediaWiki\restoreWarnings();
2496
2497         # This check may also protect against code injection in
2498         # case of broken installations.
2499         if ( !$haveDiff ) {
2500                 wfDebug( "diff executable not found\n" );
2501                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2502                 $format = new UnifiedDiffFormatter();
2503                 return $format->format( $diffs );
2504         }
2505
2506         # Make temporary files
2507         $td = wfTempDir();
2508         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2509         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2510
2511         fwrite( $oldtextFile, $before );
2512         fclose( $oldtextFile );
2513         fwrite( $newtextFile, $after );
2514         fclose( $newtextFile );
2515
2516         // Get the diff of the two files
2517         $cmd = "$wgDiff " . $params . ' ' . Shell::escape( $oldtextName, $newtextName );
2518
2519         $h = popen( $cmd, 'r' );
2520         if ( !$h ) {
2521                 unlink( $oldtextName );
2522                 unlink( $newtextName );
2523                 throw new Exception( __METHOD__ . '(): popen() failed' );
2524         }
2525
2526         $diff = '';
2527
2528         do {
2529                 $data = fread( $h, 8192 );
2530                 if ( strlen( $data ) == 0 ) {
2531                         break;
2532                 }
2533                 $diff .= $data;
2534         } while ( true );
2535
2536         // Clean up
2537         pclose( $h );
2538         unlink( $oldtextName );
2539         unlink( $newtextName );
2540
2541         // Kill the --- and +++ lines. They're not useful.
2542         $diff_lines = explode( "\n", $diff );
2543         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2544                 unset( $diff_lines[0] );
2545         }
2546         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2547                 unset( $diff_lines[1] );
2548         }
2549
2550         $diff = implode( "\n", $diff_lines );
2551
2552         return $diff;
2553 }
2554
2555 /**
2556  * This function works like "use VERSION" in Perl, the program will die with a
2557  * backtrace if the current version of PHP is less than the version provided
2558  *
2559  * This is useful for extensions which due to their nature are not kept in sync
2560  * with releases, and might depend on other versions of PHP than the main code
2561  *
2562  * Note: PHP might die due to parsing errors in some cases before it ever
2563  *       manages to call this function, such is life
2564  *
2565  * @see perldoc -f use
2566  *
2567  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2568  *
2569  * @deprecated since 1.30
2570  *
2571  * @throws MWException
2572  */
2573 function wfUsePHP( $req_ver ) {
2574         $php_ver = PHP_VERSION;
2575
2576         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2577                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2578         }
2579 }
2580
2581 /**
2582  * This function works like "use VERSION" in Perl except it checks the version
2583  * of MediaWiki, the program will die with a backtrace if the current version
2584  * of MediaWiki is less than the version provided.
2585  *
2586  * This is useful for extensions which due to their nature are not kept in sync
2587  * with releases
2588  *
2589  * Note: Due to the behavior of PHP's version_compare() which is used in this
2590  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2591  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2592  * targeted version number. For example if you wanted to allow any variation
2593  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2594  * not result in the same comparison due to the internal logic of
2595  * version_compare().
2596  *
2597  * @see perldoc -f use
2598  *
2599  * @deprecated since 1.26, use the "requires" property of extension.json
2600  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2601  * @throws MWException
2602  */
2603 function wfUseMW( $req_ver ) {
2604         global $wgVersion;
2605
2606         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2607                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2608         }
2609 }
2610
2611 /**
2612  * Return the final portion of a pathname.
2613  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2614  * https://bugs.php.net/bug.php?id=33898
2615  *
2616  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2617  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2618  *
2619  * @param string $path
2620  * @param string $suffix String to remove if present
2621  * @return string
2622  */
2623 function wfBaseName( $path, $suffix = '' ) {
2624         if ( $suffix == '' ) {
2625                 $encSuffix = '';
2626         } else {
2627                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2628         }
2629
2630         $matches = [];
2631         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2632                 return $matches[1];
2633         } else {
2634                 return '';
2635         }
2636 }
2637
2638 /**
2639  * Generate a relative path name to the given file.
2640  * May explode on non-matching case-insensitive paths,
2641  * funky symlinks, etc.
2642  *
2643  * @param string $path Absolute destination path including target filename
2644  * @param string $from Absolute source path, directory only
2645  * @return string
2646  */
2647 function wfRelativePath( $path, $from ) {
2648         // Normalize mixed input on Windows...
2649         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2650         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2651
2652         // Trim trailing slashes -- fix for drive root
2653         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2654         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2655
2656         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2657         $against = explode( DIRECTORY_SEPARATOR, $from );
2658
2659         if ( $pieces[0] !== $against[0] ) {
2660                 // Non-matching Windows drive letters?
2661                 // Return a full path.
2662                 return $path;
2663         }
2664
2665         // Trim off common prefix
2666         while ( count( $pieces ) && count( $against )
2667                 && $pieces[0] == $against[0] ) {
2668                 array_shift( $pieces );
2669                 array_shift( $against );
2670         }
2671
2672         // relative dots to bump us to the parent
2673         while ( count( $against ) ) {
2674                 array_unshift( $pieces, '..' );
2675                 array_shift( $against );
2676         }
2677
2678         array_push( $pieces, wfBaseName( $path ) );
2679
2680         return implode( DIRECTORY_SEPARATOR, $pieces );
2681 }
2682
2683 /**
2684  * Convert an arbitrarily-long digit string from one numeric base
2685  * to another, optionally zero-padding to a minimum column width.
2686  *
2687  * Supports base 2 through 36; digit values 10-36 are represented
2688  * as lowercase letters a-z. Input is case-insensitive.
2689  *
2690  * @deprecated since 1.27 Use Wikimedia\base_convert() directly
2691  *
2692  * @param string $input Input number
2693  * @param int $sourceBase Base of the input number
2694  * @param int $destBase Desired base of the output
2695  * @param int $pad Minimum number of digits in the output (pad with zeroes)
2696  * @param bool $lowercase Whether to output in lowercase or uppercase
2697  * @param string $engine Either "gmp", "bcmath", or "php"
2698  * @return string|bool The output number as a string, or false on error
2699  */
2700 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
2701         $lowercase = true, $engine = 'auto'
2702 ) {
2703         wfDeprecated( __FUNCTION__, '1.27' );
2704         return Wikimedia\base_convert( $input, $sourceBase, $destBase, $pad, $lowercase, $engine );
2705 }
2706
2707 /**
2708  * Reset the session id
2709  *
2710  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2711  * @since 1.22
2712  */
2713 function wfResetSessionID() {
2714         wfDeprecated( __FUNCTION__, '1.27' );
2715         $session = SessionManager::getGlobalSession();
2716         $delay = $session->delaySave();
2717
2718         $session->resetId();
2719
2720         // Make sure a session is started, since that's what the old
2721         // wfResetSessionID() did.
2722         if ( session_id() !== $session->getId() ) {
2723                 wfSetupSession( $session->getId() );
2724         }
2725
2726         ScopedCallback::consume( $delay );
2727 }
2728
2729 /**
2730  * Initialise php session
2731  *
2732  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2733  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2734  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2735  *  here), then calling $session->persist().
2736  * @param bool|string $sessionId
2737  */
2738 function wfSetupSession( $sessionId = false ) {
2739         wfDeprecated( __FUNCTION__, '1.27' );
2740
2741         if ( $sessionId ) {
2742                 session_id( $sessionId );
2743         }
2744
2745         $session = SessionManager::getGlobalSession();
2746         $session->persist();
2747
2748         if ( session_id() !== $session->getId() ) {
2749                 session_id( $session->getId() );
2750         }
2751         MediaWiki\quietCall( 'session_start' );
2752 }
2753
2754 /**
2755  * Get an object from the precompiled serialized directory
2756  *
2757  * @param string $name
2758  * @return mixed The variable on success, false on failure
2759  */
2760 function wfGetPrecompiledData( $name ) {
2761         global $IP;
2762
2763         $file = "$IP/serialized/$name";
2764         if ( file_exists( $file ) ) {
2765                 $blob = file_get_contents( $file );
2766                 if ( $blob ) {
2767                         return unserialize( $blob );
2768                 }
2769         }
2770         return false;
2771 }
2772
2773 /**
2774  * Make a cache key for the local wiki.
2775  *
2776  * @deprecated since 1.30 Call makeKey on a BagOStuff instance
2777  * @param string $args,...
2778  * @return string
2779  */
2780 function wfMemcKey( /*...*/ ) {
2781         return call_user_func_array(
2782                 [ ObjectCache::getLocalClusterInstance(), 'makeKey' ],
2783                 func_get_args()
2784         );
2785 }
2786
2787 /**
2788  * Make a cache key for a foreign DB.
2789  *
2790  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2791  *
2792  * @param string $db
2793  * @param string $prefix
2794  * @param string $args,...
2795  * @return string
2796  */
2797 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
2798         $args = array_slice( func_get_args(), 2 );
2799         $keyspace = $prefix ? "$db-$prefix" : $db;
2800         return call_user_func_array(
2801                 [ ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ],
2802                 [ $keyspace, $args ]
2803         );
2804 }
2805
2806 /**
2807  * Make a cache key with database-agnostic prefix.
2808  *
2809  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
2810  * instead. Must have a prefix as otherwise keys that use a database name
2811  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
2812  *
2813  * @deprecated since 1.30 Call makeGlobalKey on a BagOStuff instance
2814  * @since 1.26
2815  * @param string $args,...
2816  * @return string
2817  */
2818 function wfGlobalCacheKey( /*...*/ ) {
2819         return call_user_func_array(
2820                 [ ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ],
2821                 func_get_args()
2822         );
2823 }
2824
2825 /**
2826  * Get an ASCII string identifying this wiki
2827  * This is used as a prefix in memcached keys
2828  *
2829  * @return string
2830  */
2831 function wfWikiID() {
2832         global $wgDBprefix, $wgDBname;
2833         if ( $wgDBprefix ) {
2834                 return "$wgDBname-$wgDBprefix";
2835         } else {
2836                 return $wgDBname;
2837         }
2838 }
2839
2840 /**
2841  * Split a wiki ID into DB name and table prefix
2842  *
2843  * @param string $wiki
2844  *
2845  * @return array
2846  */
2847 function wfSplitWikiID( $wiki ) {
2848         $bits = explode( '-', $wiki, 2 );
2849         if ( count( $bits ) < 2 ) {
2850                 $bits[] = '';
2851         }
2852         return $bits;
2853 }
2854
2855 /**
2856  * Get a Database object.
2857  *
2858  * @param int $db Index of the connection to get. May be DB_MASTER for the
2859  *            master (for write queries), DB_REPLICA for potentially lagged read
2860  *            queries, or an integer >= 0 for a particular server.
2861  *
2862  * @param string|string[] $groups Query groups. An array of group names that this query
2863  *                belongs to. May contain a single string if the query is only
2864  *                in one group.
2865  *
2866  * @param string|bool $wiki The wiki ID, or false for the current wiki
2867  *
2868  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
2869  * will always return the same object, unless the underlying connection or load
2870  * balancer is manually destroyed.
2871  *
2872  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
2873  * updater to ensure that a proper database is being updated.
2874  *
2875  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
2876  *       on an injected instance of LoadBalancer.
2877  *
2878  * @return \Wikimedia\Rdbms\Database
2879  */
2880 function wfGetDB( $db, $groups = [], $wiki = false ) {
2881         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
2882 }
2883
2884 /**
2885  * Get a load balancer object.
2886  *
2887  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancer()
2888  *              or MediaWikiServices::getDBLoadBalancerFactory() instead.
2889  *
2890  * @param string|bool $wiki Wiki ID, or false for the current wiki
2891  * @return \Wikimedia\Rdbms\LoadBalancer
2892  */
2893 function wfGetLB( $wiki = false ) {
2894         if ( $wiki === false ) {
2895                 return MediaWikiServices::getInstance()->getDBLoadBalancer();
2896         } else {
2897                 $factory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2898                 return $factory->getMainLB( $wiki );
2899         }
2900 }
2901
2902 /**
2903  * Get the load balancer factory object
2904  *
2905  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancerFactory() instead.
2906  *
2907  * @return \Wikimedia\Rdbms\LBFactory
2908  */
2909 function wfGetLBFactory() {
2910         return MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
2911 }
2912
2913 /**
2914  * Find a file.
2915  * Shortcut for RepoGroup::singleton()->findFile()
2916  *
2917  * @param string $title String or Title object
2918  * @param array $options Associative array of options (see RepoGroup::findFile)
2919  * @return File|bool File, or false if the file does not exist
2920  */
2921 function wfFindFile( $title, $options = [] ) {
2922         return RepoGroup::singleton()->findFile( $title, $options );
2923 }
2924
2925 /**
2926  * Get an object referring to a locally registered file.
2927  * Returns a valid placeholder object if the file does not exist.
2928  *
2929  * @param Title|string $title
2930  * @return LocalFile|null A File, or null if passed an invalid Title
2931  */
2932 function wfLocalFile( $title ) {
2933         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
2934 }
2935
2936 /**
2937  * Should low-performance queries be disabled?
2938  *
2939  * @return bool
2940  * @codeCoverageIgnore
2941  */
2942 function wfQueriesMustScale() {
2943         global $wgMiserMode;
2944         return $wgMiserMode
2945                 || ( SiteStats::pages() > 100000
2946                 && SiteStats::edits() > 1000000
2947                 && SiteStats::users() > 10000 );
2948 }
2949
2950 /**
2951  * Get the path to a specified script file, respecting file
2952  * extensions; this is a wrapper around $wgScriptPath etc.
2953  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
2954  *
2955  * @param string $script Script filename, sans extension
2956  * @return string
2957  */
2958 function wfScript( $script = 'index' ) {
2959         global $wgScriptPath, $wgScript, $wgLoadScript;
2960         if ( $script === 'index' ) {
2961                 return $wgScript;
2962         } elseif ( $script === 'load' ) {
2963                 return $wgLoadScript;
2964         } else {
2965                 return "{$wgScriptPath}/{$script}.php";
2966         }
2967 }
2968
2969 /**
2970  * Get the script URL.
2971  *
2972  * @return string Script URL
2973  */
2974 function wfGetScriptUrl() {
2975         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
2976                 /* as it was called, minus the query string.
2977                  *
2978                  * Some sites use Apache rewrite rules to handle subdomains,
2979                  * and have PHP set up in a weird way that causes PHP_SELF
2980                  * to contain the rewritten URL instead of the one that the
2981                  * outside world sees.
2982                  *
2983                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
2984                  * provides containing the "before" URL.
2985                  */
2986                 return $_SERVER['SCRIPT_NAME'];
2987         } else {
2988                 return $_SERVER['URL'];
2989         }
2990 }
2991
2992 /**
2993  * Convenience function converts boolean values into "true"
2994  * or "false" (string) values
2995  *
2996  * @param bool $value
2997  * @return string
2998  */
2999 function wfBoolToStr( $value ) {
3000         return $value ? 'true' : 'false';
3001 }
3002
3003 /**
3004  * Get a platform-independent path to the null file, e.g. /dev/null
3005  *
3006  * @return string
3007  */
3008 function wfGetNull() {
3009         return wfIsWindows() ? 'NUL' : '/dev/null';
3010 }
3011
3012 /**
3013  * Waits for the replica DBs to catch up to the master position
3014  *
3015  * Use this when updating very large numbers of rows, as in maintenance scripts,
3016  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
3017  *
3018  * By default this waits on the main DB cluster of the current wiki.
3019  * If $cluster is set to "*" it will wait on all DB clusters, including
3020  * external ones. If the lag being waiting on is caused by the code that
3021  * does this check, it makes since to use $ifWritesSince, particularly if
3022  * cluster is "*", to avoid excess overhead.
3023  *
3024  * Never call this function after a big DB write that is still in a transaction.
3025  * This only makes sense after the possible lag inducing changes were committed.
3026  *
3027  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3028  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3029  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3030  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3031  * @return bool Success (able to connect and no timeouts reached)
3032  * @deprecated since 1.27 Use LBFactory::waitForReplication
3033  */
3034 function wfWaitForSlaves(
3035         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3036 ) {
3037         if ( $timeout === null ) {
3038                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3039         }
3040
3041         if ( $cluster === '*' ) {
3042                 $cluster = false;
3043                 $wiki = false;
3044         } elseif ( $wiki === false ) {
3045                 $wiki = wfWikiID();
3046         }
3047
3048         try {
3049                 wfGetLBFactory()->waitForReplication( [
3050                         'wiki' => $wiki,
3051                         'cluster' => $cluster,
3052                         'timeout' => $timeout,
3053                         // B/C: first argument used to be "max seconds of lag"; ignore such values
3054                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
3055                 ] );
3056         } catch ( DBReplicationWaitError $e ) {
3057                 return false;
3058         }
3059
3060         return true;
3061 }
3062
3063 /**
3064  * Count down from $seconds to zero on the terminal, with a one-second pause
3065  * between showing each number. For use in command-line scripts.
3066  *
3067  * @deprecated since 1.31, use Maintenance::countDown()
3068  *
3069  * @codeCoverageIgnore
3070  * @param int $seconds
3071  */
3072 function wfCountDown( $seconds ) {
3073         for ( $i = $seconds; $i >= 0; $i-- ) {
3074                 if ( $i != $seconds ) {
3075                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3076                 }
3077                 echo $i;
3078                 flush();
3079                 if ( $i ) {
3080                         sleep( 1 );
3081                 }
3082         }
3083         echo "\n";
3084 }
3085
3086 /**
3087  * Replace all invalid characters with '-'.
3088  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
3089  * By default, $wgIllegalFileChars includes ':', '/', '\'.
3090  *
3091  * @param string $name Filename to process
3092  * @return string
3093  */
3094 function wfStripIllegalFilenameChars( $name ) {
3095         global $wgIllegalFileChars;
3096         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3097         $name = preg_replace(
3098                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3099                 '-',
3100                 $name
3101         );
3102         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
3103         $name = wfBaseName( $name );
3104         return $name;
3105 }
3106
3107 /**
3108  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3109  *
3110  * @return int Resulting value of the memory limit.
3111  */
3112 function wfMemoryLimit() {
3113         global $wgMemoryLimit;
3114         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3115         if ( $memlimit != -1 ) {
3116                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3117                 if ( $conflimit == -1 ) {
3118                         wfDebug( "Removing PHP's memory limit\n" );
3119                         MediaWiki\suppressWarnings();
3120                         ini_set( 'memory_limit', $conflimit );
3121                         MediaWiki\restoreWarnings();
3122                         return $conflimit;
3123                 } elseif ( $conflimit > $memlimit ) {
3124                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3125                         MediaWiki\suppressWarnings();
3126                         ini_set( 'memory_limit', $conflimit );
3127                         MediaWiki\restoreWarnings();
3128                         return $conflimit;
3129                 }
3130         }
3131         return $memlimit;
3132 }
3133
3134 /**
3135  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3136  *
3137  * @return int Prior time limit
3138  * @since 1.26
3139  */
3140 function wfTransactionalTimeLimit() {
3141         global $wgTransactionalTimeLimit;
3142
3143         $timeLimit = ini_get( 'max_execution_time' );
3144         // Note that CLI scripts use 0
3145         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3146                 set_time_limit( $wgTransactionalTimeLimit );
3147         }
3148
3149         ignore_user_abort( true ); // ignore client disconnects
3150
3151         return $timeLimit;
3152 }
3153
3154 /**
3155  * Converts shorthand byte notation to integer form
3156  *
3157  * @param string $string
3158  * @param int $default Returned if $string is empty
3159  * @return int
3160  */
3161 function wfShorthandToInteger( $string = '', $default = -1 ) {
3162         $string = trim( $string );
3163         if ( $string === '' ) {
3164                 return $default;
3165         }
3166         $last = $string[strlen( $string ) - 1];
3167         $val = intval( $string );
3168         switch ( $last ) {
3169                 case 'g':
3170                 case 'G':
3171                         $val *= 1024;
3172                         // break intentionally missing
3173                 case 'm':
3174                 case 'M':
3175                         $val *= 1024;
3176                         // break intentionally missing
3177                 case 'k':
3178                 case 'K':
3179                         $val *= 1024;
3180         }
3181
3182         return $val;
3183 }
3184
3185 /**
3186  * Get the normalised IETF language tag
3187  * See unit test for examples.
3188  * See mediawiki.language.bcp47 for the JavaScript implementation.
3189  *
3190  * @deprecated since 1.31, use LanguageCode::bcp47() directly.
3191  *
3192  * @param string $code The language code.
3193  * @return string The language code which complying with BCP 47 standards.
3194  */
3195 function wfBCP47( $code ) {
3196         return LanguageCode::bcp47( $code );
3197 }
3198
3199 /**
3200  * Get a specific cache object.
3201  *
3202  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3203  * @return BagOStuff
3204  */
3205 function wfGetCache( $cacheType ) {
3206         return ObjectCache::getInstance( $cacheType );
3207 }
3208
3209 /**
3210  * Get the main cache object
3211  *
3212  * @return BagOStuff
3213  */
3214 function wfGetMainCache() {
3215         global $wgMainCacheType;
3216         return ObjectCache::getInstance( $wgMainCacheType );
3217 }
3218
3219 /**
3220  * Get the cache object used by the message cache
3221  *
3222  * @return BagOStuff
3223  */
3224 function wfGetMessageCacheStorage() {
3225         global $wgMessageCacheType;
3226         return ObjectCache::getInstance( $wgMessageCacheType );
3227 }
3228
3229 /**
3230  * Get the cache object used by the parser cache
3231  *
3232  * @deprecated since 1.30, use MediaWikiServices::getParserCache()->getCacheStorage()
3233  * @return BagOStuff
3234  */
3235 function wfGetParserCacheStorage() {
3236         global $wgParserCacheType;
3237         return ObjectCache::getInstance( $wgParserCacheType );
3238 }
3239
3240 /**
3241  * Call hook functions defined in $wgHooks
3242  *
3243  * @param string $event Event name
3244  * @param array $args Parameters passed to hook functions
3245  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3246  *
3247  * @return bool True if no handler aborted the hook
3248  * @deprecated since 1.25 - use Hooks::run
3249  */
3250 function wfRunHooks( $event, array $args = [], $deprecatedVersion = null ) {
3251         wfDeprecated( __METHOD__, '1.25' );
3252         return Hooks::run( $event, $args, $deprecatedVersion );
3253 }
3254
3255 /**
3256  * Wrapper around php's unpack.
3257  *
3258  * @param string $format The format string (See php's docs)
3259  * @param string $data A binary string of binary data
3260  * @param int|bool $length The minimum length of $data or false. This is to
3261  *      prevent reading beyond the end of $data. false to disable the check.
3262  *
3263  * Also be careful when using this function to read unsigned 32 bit integer
3264  * because php might make it negative.
3265  *
3266  * @throws MWException If $data not long enough, or if unpack fails
3267  * @return array Associative array of the extracted data
3268  */
3269 function wfUnpack( $format, $data, $length = false ) {
3270         if ( $length !== false ) {
3271                 $realLen = strlen( $data );
3272                 if ( $realLen < $length ) {
3273                         throw new MWException( "Tried to use wfUnpack on a "
3274                                 . "string of length $realLen, but needed one "
3275                                 . "of at least length $length."
3276                         );
3277                 }
3278         }
3279
3280         MediaWiki\suppressWarnings();
3281         $result = unpack( $format, $data );
3282         MediaWiki\restoreWarnings();
3283
3284         if ( $result === false ) {
3285                 // If it cannot extract the packed data.
3286                 throw new MWException( "unpack could not unpack binary data" );
3287         }
3288         return $result;
3289 }
3290
3291 /**
3292  * Determine if an image exists on the 'bad image list'.
3293  *
3294  * The format of MediaWiki:Bad_image_list is as follows:
3295  *    * Only list items (lines starting with "*") are considered
3296  *    * The first link on a line must be a link to a bad image
3297  *    * Any subsequent links on the same line are considered to be exceptions,
3298  *      i.e. articles where the image may occur inline.
3299  *
3300  * @param string $name The image name to check
3301  * @param Title|bool $contextTitle The page on which the image occurs, if known
3302  * @param string $blacklist Wikitext of a file blacklist
3303  * @return bool
3304  */
3305 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3306         # Handle redirects; callers almost always hit wfFindFile() anyway,
3307         # so just use that method because it has a fast process cache.
3308         $file = wfFindFile( $name ); // get the final name
3309         $name = $file ? $file->getTitle()->getDBkey() : $name;
3310
3311         # Run the extension hook
3312         $bad = false;
3313         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3314                 return (bool)$bad;
3315         }
3316
3317         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3318         $key = $cache->makeKey(
3319                 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist )
3320         );
3321         $badImages = $cache->get( $key );
3322
3323         if ( $badImages === false ) { // cache miss
3324                 if ( $blacklist === null ) {
3325                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3326                 }
3327                 # Build the list now
3328                 $badImages = [];
3329                 $lines = explode( "\n", $blacklist );
3330                 foreach ( $lines as $line ) {
3331                         # List items only
3332                         if ( substr( $line, 0, 1 ) !== '*' ) {
3333                                 continue;
3334                         }
3335
3336                         # Find all links
3337                         $m = [];
3338                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3339                                 continue;
3340                         }
3341
3342                         $exceptions = [];
3343                         $imageDBkey = false;
3344                         foreach ( $m[1] as $i => $titleText ) {
3345                                 $title = Title::newFromText( $titleText );
3346                                 if ( !is_null( $title ) ) {
3347                                         if ( $i == 0 ) {
3348                                                 $imageDBkey = $title->getDBkey();
3349                                         } else {
3350                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3351                                         }
3352                                 }
3353                         }
3354
3355                         if ( $imageDBkey !== false ) {
3356                                 $badImages[$imageDBkey] = $exceptions;
3357                         }
3358                 }
3359                 $cache->set( $key, $badImages, 60 );
3360         }
3361
3362         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3363         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3364
3365         return $bad;
3366 }
3367
3368 /**
3369  * Determine whether the client at a given source IP is likely to be able to
3370  * access the wiki via HTTPS.
3371  *
3372  * @param string $ip The IPv4/6 address in the normal human-readable form
3373  * @return bool
3374  */
3375 function wfCanIPUseHTTPS( $ip ) {
3376         $canDo = true;
3377         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3378         return !!$canDo;
3379 }
3380
3381 /**
3382  * Determine input string is represents as infinity
3383  *
3384  * @param string $str The string to determine
3385  * @return bool
3386  * @since 1.25
3387  */
3388 function wfIsInfinity( $str ) {
3389         // These are hardcoded elsewhere in MediaWiki (e.g. mediawiki.special.block.js).
3390         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3391         return in_array( $str, $infinityValues );
3392 }
3393
3394 /**
3395  * Returns true if these thumbnail parameters match one that MediaWiki
3396  * requests from file description pages and/or parser output.
3397  *
3398  * $params is considered non-standard if they involve a non-standard
3399  * width or any non-default parameters aside from width and page number.
3400  * The number of possible files with standard parameters is far less than
3401  * that of all combinations; rate-limiting for them can thus be more generious.
3402  *
3403  * @param File $file
3404  * @param array $params
3405  * @return bool
3406  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3407  */
3408 function wfThumbIsStandard( File $file, array $params ) {
3409         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3410
3411         $multipliers = [ 1 ];
3412         if ( $wgResponsiveImages ) {
3413                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3414                 // @see Linker::processResponsiveImages
3415                 $multipliers[] = 1.5;
3416                 $multipliers[] = 2;
3417         }
3418
3419         $handler = $file->getHandler();
3420         if ( !$handler || !isset( $params['width'] ) ) {
3421                 return false;
3422         }
3423
3424         $basicParams = [];
3425         if ( isset( $params['page'] ) ) {
3426                 $basicParams['page'] = $params['page'];
3427         }
3428
3429         $thumbLimits = [];
3430         $imageLimits = [];
3431         // Expand limits to account for multipliers
3432         foreach ( $multipliers as $multiplier ) {
3433                 $thumbLimits = array_merge( $thumbLimits, array_map(
3434                         function ( $width ) use ( $multiplier ) {
3435                                 return round( $width * $multiplier );
3436                         }, $wgThumbLimits )
3437                 );
3438                 $imageLimits = array_merge( $imageLimits, array_map(
3439                         function ( $pair ) use ( $multiplier ) {
3440                                 return [
3441                                         round( $pair[0] * $multiplier ),
3442                                         round( $pair[1] * $multiplier ),
3443                                 ];
3444                         }, $wgImageLimits )
3445                 );
3446         }
3447
3448         // Check if the width matches one of $wgThumbLimits
3449         if ( in_array( $params['width'], $thumbLimits ) ) {
3450                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3451                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3452                 $handler->normaliseParams( $file, $normalParams );
3453         } else {
3454                 // If not, then check if the width matchs one of $wgImageLimits
3455                 $match = false;
3456                 foreach ( $imageLimits as $pair ) {
3457                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3458                         // Decide whether the thumbnail should be scaled on width or height.
3459                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3460                         $handler->normaliseParams( $file, $normalParams );
3461                         // Check if this standard thumbnail size maps to the given width
3462                         if ( $normalParams['width'] == $params['width'] ) {
3463                                 $match = true;
3464                                 break;
3465                         }
3466                 }
3467                 if ( !$match ) {
3468                         return false; // not standard for description pages
3469                 }
3470         }
3471
3472         // Check that the given values for non-page, non-width, params are just defaults
3473         foreach ( $params as $key => $value ) {
3474                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3475                         return false;
3476                 }
3477         }
3478
3479         return true;
3480 }
3481
3482 /**
3483  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3484  *
3485  * Values that exist in both values will be combined with += (all values of the array
3486  * of $newValues will be added to the values of the array of $baseArray, while values,
3487  * that exists in both, the value of $baseArray will be used).
3488  *
3489  * @param array $baseArray The array where you want to add the values of $newValues to
3490  * @param array $newValues An array with new values
3491  * @return array The combined array
3492  * @since 1.26
3493  */
3494 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3495         // First merge items that are in both arrays
3496         foreach ( $baseArray as $name => &$groupVal ) {
3497                 if ( isset( $newValues[$name] ) ) {
3498                         $groupVal += $newValues[$name];
3499                 }
3500         }
3501         // Now add items that didn't exist yet
3502         $baseArray += $newValues;
3503
3504         return $baseArray;
3505 }
3506
3507 /**
3508  * Get system resource usage of current request context.
3509  * Invokes the getrusage(2) system call, requesting RUSAGE_SELF if on PHP5
3510  * or RUSAGE_THREAD if on HHVM. Returns false if getrusage is not available.
3511  *
3512  * @since 1.24
3513  * @return array|bool Resource usage data or false if no data available.
3514  */
3515 function wfGetRusage() {
3516         if ( !function_exists( 'getrusage' ) ) {
3517                 return false;
3518         } elseif ( defined( 'HHVM_VERSION' ) && PHP_OS === 'Linux' ) {
3519                 return getrusage( 2 /* RUSAGE_THREAD */ );
3520         } else {
3521                 return getrusage( 0 /* RUSAGE_SELF */ );
3522         }
3523 }
3524
3525 /**
3526  * Begin profiling of a function
3527  * @param string $functionname Name of the function we will profile
3528  * @deprecated since 1.25
3529  */
3530 function wfProfileIn( $functionname ) {
3531 }
3532
3533 /**
3534  * Stop profiling of a function
3535  * @param string $functionname Name of the function we have profiled
3536  * @deprecated since 1.25
3537  */
3538 function wfProfileOut( $functionname = 'missing' ) {
3539 }