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
  30 // Hide compatibility functions from Doxygen
  31 /// @cond
  32
  33 /**
  34  * Compatibility functions
  35  *
  36  * We support PHP 5.3.3 and up.
  37  * Re-implementations of newer functions or functions in non-standard
  38  * PHP extensions may be included here.
  39  */
  40
  41 if ( !function_exists( 'mb_substr' ) ) {
  42         /**
  43          * @codeCoverageIgnore
  44          * @see Fallback::mb_substr
  45          * @return string
  46          */
  47         function mb_substr( $str, $start, $count = 'end' ) {
  48                 return Fallback::mb_substr( $str, $start, $count );
  49         }
  50
  51         /**
  52          * @codeCoverageIgnore
  53          * @see Fallback::mb_substr_split_unicode
  54          * @return int
  55          */
  56         function mb_substr_split_unicode( $str, $splitPos ) {
  57                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  58         }
  59 }
  60
  61 if ( !function_exists( 'mb_strlen' ) ) {
  62         /**
  63          * @codeCoverageIgnore
  64          * @see Fallback::mb_strlen
  65          * @return int
  66          */
  67         function mb_strlen( $str, $enc = '' ) {
  68                 return Fallback::mb_strlen( $str, $enc );
  69         }
  70 }
  71
  72 if ( !function_exists( 'mb_strpos' ) ) {
  73         /**
  74          * @codeCoverageIgnore
  75          * @see Fallback::mb_strpos
  76          * @return int
  77          */
  78         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  79                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  80         }
  81 }
  82
  83 if ( !function_exists( 'mb_strrpos' ) ) {
  84         /**
  85          * @codeCoverageIgnore
  86          * @see Fallback::mb_strrpos
  87          * @return int
  88          */
  89         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  90                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  91         }
  92 }
  93
  94 // gzdecode function only exists in PHP >= 5.4.0
  95 // http://php.net/gzdecode
  96 if ( !function_exists( 'gzdecode' ) ) {
  97         /**
  98          * @codeCoverageIgnore
  99          * @param string $data
 100          * @return string
 101          */
 102         function gzdecode( $data ) {
 103                 return gzinflate( substr( $data, 10, -8 ) );
 104         }
 105 }
 106
 107 // hash_equals function only exists in PHP >= 5.6.0
 108 // http://php.net/hash_equals
 109 if ( !function_exists( 'hash_equals' ) ) {
 110         /**
 111          * Check whether a user-provided string is equal to a fixed-length secret string
 112          * without revealing bytes of the secret string through timing differences.
 113          *
 114          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 115          * function in C) is to compare corresponding bytes and stop at the first difference,
 116          * which would take longer for a partial match than for a complete mismatch. This
 117          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 118          * and the other may come from an attacker. Statistical analysis of timing measurements
 119          * over many requests may allow the attacker to guess the string's bytes one at a time
 120          * (and check his guesses) even if the timing differences are extremely small.
 121          *
 122          * When making such a security-sensitive comparison, it is essential that the sequence
 123          * in which instructions are executed and memory locations are accessed not depend on
 124          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 125          * the inevitable leakage of the string's length. That is generally known anyway as
 126          * a chararacteristic of the hash function used to compute the secret value.
 127          *
 128          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 129          *
 130          * @codeCoverageIgnore
 131          * @param string $known_string Fixed-length secret string to compare against
 132          * @param string $user_string User-provided string
 133          * @return bool True if the strings are the same, false otherwise
 134          */
 135         function hash_equals( $known_string, $user_string ) {
 136                 // Strict type checking as in PHP's native implementation
 137                 if ( !is_string( $known_string ) ) {
 138                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 139                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 140
 141                         return false;
 142                 }
 143
 144                 if ( !is_string( $user_string ) ) {
 145                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 146                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 147
 148                         return false;
 149                 }
 150
 151                 $known_string_len = strlen( $known_string );
 152                 if ( $known_string_len !== strlen( $user_string ) ) {
 153                         return false;
 154                 }
 155
 156                 $result = 0;
 157                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 158                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 159                 }
 160
 161                 return ( $result === 0 );
 162         }
 163 }
 164 /// @endcond
 165
 166 /**
 167  * Load an extension
 168  *
 169  * This queues an extension to be loaded through
 170  * the ExtensionRegistry system.
 171  *
 172  * @param string $ext Name of the extension to load
 173  * @param string|null $path Absolute path of where to find the extension.json file
 174  * @since 1.25
 175  */
 176 function wfLoadExtension( $ext, $path = null ) {
 177         if ( !$path ) {
 178                 global $wgExtensionDirectory;
 179                 $path = "$wgExtensionDirectory/$ext/extension.json";
 180         }
 181         ExtensionRegistry::getInstance()->queue( $path );
 182 }
 183
 184 /**
 185  * Load multiple extensions at once
 186  *
 187  * Same as wfLoadExtension, but more efficient if you
 188  * are loading multiple extensions.
 189  *
 190  * If you want to specify custom paths, you should interact with
 191  * ExtensionRegistry directly.
 192  *
 193  * @see wfLoadExtension
 194  * @param string[] $exts Array of extension names to load
 195  * @since 1.25
 196  */
 197 function wfLoadExtensions( array $exts ) {
 198         global $wgExtensionDirectory;
 199         $registry = ExtensionRegistry::getInstance();
 200         foreach ( $exts as $ext ) {
 201                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 202         }
 203 }
 204
 205 /**
 206  * Load a skin
 207  *
 208  * @see wfLoadExtension
 209  * @param string $skin Name of the extension to load
 210  * @param string|null $path Absolute path of where to find the skin.json file
 211  * @since 1.25
 212  */
 213 function wfLoadSkin( $skin, $path = null ) {
 214         if ( !$path ) {
 215                 global $wgStyleDirectory;
 216                 $path = "$wgStyleDirectory/$skin/skin.json";
 217         }
 218         ExtensionRegistry::getInstance()->queue( $path );
 219 }
 220
 221 /**
 222  * Load multiple skins at once
 223  *
 224  * @see wfLoadExtensions
 225  * @param string[] $skins Array of extension names to load
 226  * @since 1.25
 227  */
 228 function wfLoadSkins( array $skins ) {
 229         global $wgStyleDirectory;
 230         $registry = ExtensionRegistry::getInstance();
 231         foreach ( $skins as $skin ) {
 232                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 233         }
 234 }
 235
 236 /**
 237  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 238  * @param array $a
 239  * @param array $b
 240  * @return array
 241  */
 242 function wfArrayDiff2( $a, $b ) {
 243         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 244 }
 245
 246 /**
 247  * @param array|string $a
 248  * @param array|string $b
 249  * @return int
 250  */
 251 function wfArrayDiff2_cmp( $a, $b ) {
 252         if ( is_string( $a ) && is_string( $b ) ) {
 253                 return strcmp( $a, $b );
 254         } elseif ( count( $a ) !== count( $b ) ) {
 255                 return count( $a ) < count( $b ) ? -1 : 1;
 256         } else {
 257                 reset( $a );
 258                 reset( $b );
 259                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 260                         $cmp = strcmp( $valueA, $valueB );
 261                         if ( $cmp !== 0 ) {
 262                                 return $cmp;
 263                         }
 264                 }
 265                 return 0;
 266         }
 267 }
 268
 269 /**
 270  * Appends to second array if $value differs from that in $default
 271  *
 272  * @param string|int $key
 273  * @param mixed $value
 274  * @param mixed $default
 275  * @param array $changed Array to alter
 276  * @throws MWException
 277  */
 278 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 279         if ( is_null( $changed ) ) {
 280                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 281         }
 282         if ( $default[$key] !== $value ) {
 283                 $changed[$key] = $value;
 284         }
 285 }
 286
 287 /**
 288  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 289  * e.g.
 290  *      wfMergeErrorArrays(
 291  *              array( array( 'x' ) ),
 292  *              array( array( 'x', '2' ) ),
 293  *              array( array( 'x' ) ),
 294  *              array( array( 'y' ) )
 295  *      );
 296  * returns:
 297  *              array(
 298  *              array( 'x', '2' ),
 299  *              array( 'x' ),
 300  *              array( 'y' )
 301  *      )
 302  *
 303  * @param array $array1,...
 304  * @return array
 305  */
 306 function wfMergeErrorArrays( /*...*/ ) {
 307         $args = func_get_args();
 308         $out = array();
 309         foreach ( $args as $errors ) {
 310                 foreach ( $errors as $params ) {
 311                         $originalParams = $params;
 312                         if ( $params[0] instanceof MessageSpecifier ) {
 313                                 $msg = $params[0];
 314                                 $params = array_merge( array( $msg->getKey() ), $msg->getParams() );
 315                         }
 316                         # @todo FIXME: Sometimes get nested arrays for $params,
 317                         # which leads to E_NOTICEs
 318                         $spec = implode( "\t", $params );
 319                         $out[$spec] = $originalParams;
 320                 }
 321         }
 322         return array_values( $out );
 323 }
 324
 325 /**
 326  * Insert array into another array after the specified *KEY*
 327  *
 328  * @param array $array The array.
 329  * @param array $insert The array to insert.
 330  * @param mixed $after The key to insert after
 331  * @return array
 332  */
 333 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 334         // Find the offset of the element to insert after.
 335         $keys = array_keys( $array );
 336         $offsetByKey = array_flip( $keys );
 337
 338         $offset = $offsetByKey[$after];
 339
 340         // Insert at the specified offset
 341         $before = array_slice( $array, 0, $offset + 1, true );
 342         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 343
 344         $output = $before + $insert + $after;
 345
 346         return $output;
 347 }
 348
 349 /**
 350  * Recursively converts the parameter (an object) to an array with the same data
 351  *
 352  * @param object|array $objOrArray
 353  * @param bool $recursive
 354  * @return array
 355  */
 356 function wfObjectToArray( $objOrArray, $recursive = true ) {
 357         $array = array();
 358         if ( is_object( $objOrArray ) ) {
 359                 $objOrArray = get_object_vars( $objOrArray );
 360         }
 361         foreach ( $objOrArray as $key => $value ) {
 362                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 363                         $value = wfObjectToArray( $value );
 364                 }
 365
 366                 $array[$key] = $value;
 367         }
 368
 369         return $array;
 370 }
 371
 372 /**
 373  * Get a random decimal value between 0 and 1, in a way
 374  * not likely to give duplicate values for any realistic
 375  * number of articles.
 376  *
 377  * @note This is designed for use in relation to Special:RandomPage
 378  *       and the page_random database field.
 379  *
 380  * @return string
 381  */
 382 function wfRandom() {
 383         // The maximum random value is "only" 2^31-1, so get two random
 384         // values to reduce the chance of dupes
 385         $max = mt_getrandmax() + 1;
 386         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 387         return $rand;
 388 }
 389
 390 /**
 391  * Get a random string containing a number of pseudo-random hex characters.
 392  *
 393  * @note This is not secure, if you are trying to generate some sort
 394  *       of token please use MWCryptRand instead.
 395  *
 396  * @param int $length The length of the string to generate
 397  * @return string
 398  * @since 1.20
 399  */
 400 function wfRandomString( $length = 32 ) {
 401         $str = '';
 402         for ( $n = 0; $n < $length; $n += 7 ) {
 403                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 404         }
 405         return substr( $str, 0, $length );
 406 }
 407
 408 /**
 409  * We want some things to be included as literal characters in our title URLs
 410  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 411  * all of the following should be safe:
 412  *
 413  * ;:@&=$-_.+!*'(),
 414  *
 415  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 416  * character which should not be encoded. More importantly, google chrome
 417  * always converts %7E back to ~, and converting it in this function can
 418  * cause a redirect loop (T105265).
 419  *
 420  * But + is not safe because it's used to indicate a space; &= are only safe in
 421  * paths and not in queries (and we don't distinguish here); ' seems kind of
 422  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 423  * is reserved, we don't care.  So the list we unescape is:
 424  *
 425  * ;:@$!*(),/~
 426  *
 427  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 428  * so no fancy : for IIS7.
 429  *
 430  * %2F in the page titles seems to fatally break for some reason.
 431  *
 432  * @param string $s
 433  * @return string
 434  */
 435 function wfUrlencode( $s ) {
 436         static $needle;
 437
 438         if ( is_null( $s ) ) {
 439                 $needle = null;
 440                 return '';
 441         }
 442
 443         if ( is_null( $needle ) ) {
 444                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' );
 445                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 446                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 447                 ) {
 448                         $needle[] = '%3A';
 449                 }
 450         }
 451
 452         $s = urlencode( $s );
 453         $s = str_ireplace(
 454                 $needle,
 455                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ),
 456                 $s
 457         );
 458
 459         return $s;
 460 }
 461
 462 /**
 463  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 464  * "days=7&limit=100". Options in the first array override options in the second.
 465  * Options set to null or false will not be output.
 466  *
 467  * @param array $array1 ( String|Array )
 468  * @param array|null $array2 ( String|Array )
 469  * @param string $prefix
 470  * @return string
 471  */
 472 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 473         if ( !is_null( $array2 ) ) {
 474                 $array1 = $array1 + $array2;
 475         }
 476
 477         $cgi = '';
 478         foreach ( $array1 as $key => $value ) {
 479                 if ( !is_null( $value ) && $value !== false ) {
 480                         if ( $cgi != '' ) {
 481                                 $cgi .= '&';
 482                         }
 483                         if ( $prefix !== '' ) {
 484                                 $key = $prefix . "[$key]";
 485                         }
 486                         if ( is_array( $value ) ) {
 487                                 $firstTime = true;
 488                                 foreach ( $value as $k => $v ) {
 489                                         $cgi .= $firstTime ? '' : '&';
 490                                         if ( is_array( $v ) ) {
 491                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 492                                         } else {
 493                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 494                                         }
 495                                         $firstTime = false;
 496                                 }
 497                         } else {
 498                                 if ( is_object( $value ) ) {
 499                                         $value = $value->__toString();
 500                                 }
 501                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 502                         }
 503                 }
 504         }
 505         return $cgi;
 506 }
 507
 508 /**
 509  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 510  * its argument and returns the same string in array form.  This allows compatibility
 511  * with legacy functions that accept raw query strings instead of nice
 512  * arrays.  Of course, keys and values are urldecode()d.
 513  *
 514  * @param string $query Query string
 515  * @return string[] Array version of input
 516  */
 517 function wfCgiToArray( $query ) {
 518         if ( isset( $query[0] ) && $query[0] == '?' ) {
 519                 $query = substr( $query, 1 );
 520         }
 521         $bits = explode( '&', $query );
 522         $ret = array();
 523         foreach ( $bits as $bit ) {
 524                 if ( $bit === '' ) {
 525                         continue;
 526                 }
 527                 if ( strpos( $bit, '=' ) === false ) {
 528                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 529                         $key = $bit;
 530                         $value = '';
 531                 } else {
 532                         list( $key, $value ) = explode( '=', $bit );
 533                 }
 534                 $key = urldecode( $key );
 535                 $value = urldecode( $value );
 536                 if ( strpos( $key, '[' ) !== false ) {
 537                         $keys = array_reverse( explode( '[', $key ) );
 538                         $key = array_pop( $keys );
 539                         $temp = $value;
 540                         foreach ( $keys as $k ) {
 541                                 $k = substr( $k, 0, -1 );
 542                                 $temp = array( $k => $temp );
 543                         }
 544                         if ( isset( $ret[$key] ) ) {
 545                                 $ret[$key] = array_merge( $ret[$key], $temp );
 546                         } else {
 547                                 $ret[$key] = $temp;
 548                         }
 549                 } else {
 550                         $ret[$key] = $value;
 551                 }
 552         }
 553         return $ret;
 554 }
 555
 556 /**
 557  * Append a query string to an existing URL, which may or may not already
 558  * have query string parameters already. If so, they will be combined.
 559  *
 560  * @param string $url
 561  * @param string|string[] $query String or associative array
 562  * @return string
 563  */
 564 function wfAppendQuery( $url, $query ) {
 565         if ( is_array( $query ) ) {
 566                 $query = wfArrayToCgi( $query );
 567         }
 568         if ( $query != '' ) {
 569                 if ( false === strpos( $url, '?' ) ) {
 570                         $url .= '?';
 571                 } else {
 572                         $url .= '&';
 573                 }
 574                 $url .= $query;
 575         }
 576         return $url;
 577 }
 578
 579 /**
 580  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 581  * is correct.
 582  *
 583  * The meaning of the PROTO_* constants is as follows:
 584  * PROTO_HTTP: Output a URL starting with http://
 585  * PROTO_HTTPS: Output a URL starting with https://
 586  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 587  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 588  *    on which protocol was used for the current incoming request
 589  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 590  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 591  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 592  *
 593  * @todo this won't work with current-path-relative URLs
 594  * like "subdir/foo.html", etc.
 595  *
 596  * @param string $url Either fully-qualified or a local path + query
 597  * @param string $defaultProto One of the PROTO_* constants. Determines the
 598  *    protocol to use if $url or $wgServer is protocol-relative
 599  * @return string Fully-qualified URL, current-path-relative URL or false if
 600  *    no valid URL can be constructed
 601  */
 602 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 603         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 604                 $wgHttpsPort;
 605         if ( $defaultProto === PROTO_CANONICAL ) {
 606                 $serverUrl = $wgCanonicalServer;
 607         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 608                 // Make $wgInternalServer fall back to $wgServer if not set
 609                 $serverUrl = $wgInternalServer;
 610         } else {
 611                 $serverUrl = $wgServer;
 612                 if ( $defaultProto === PROTO_CURRENT ) {
 613                         $defaultProto = $wgRequest->getProtocol() . '://';
 614                 }
 615         }
 616
 617         // Analyze $serverUrl to obtain its protocol
 618         $bits = wfParseUrl( $serverUrl );
 619         $serverHasProto = $bits && $bits['scheme'] != '';
 620
 621         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 622                 if ( $serverHasProto ) {
 623                         $defaultProto = $bits['scheme'] . '://';
 624                 } else {
 625                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 626                         // This really isn't supposed to happen. Fall back to HTTP in this
 627                         // ridiculous case.
 628                         $defaultProto = PROTO_HTTP;
 629                 }
 630         }
 631
 632         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 633
 634         if ( substr( $url, 0, 2 ) == '//' ) {
 635                 $url = $defaultProtoWithoutSlashes . $url;
 636         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 637                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 638                 // otherwise leave it alone.
 639                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 640         }
 641
 642         $bits = wfParseUrl( $url );
 643
 644         // ensure proper port for HTTPS arrives in URL
 645         // https://phabricator.wikimedia.org/T67184
 646         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 647                 $bits['port'] = $wgHttpsPort;
 648         }
 649
 650         if ( $bits && isset( $bits['path'] ) ) {
 651                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 652                 return wfAssembleUrl( $bits );
 653         } elseif ( $bits ) {
 654                 # No path to expand
 655                 return $url;
 656         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 657                 # URL is a relative path
 658                 return wfRemoveDotSegments( $url );
 659         }
 660
 661         # Expanded URL is not valid.
 662         return false;
 663 }
 664
 665 /**
 666  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 667  * if you need to edit part of a URL and put it back together.
 668  *
 669  * This is the basic structure used (brackets contain keys for $urlParts):
 670  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 671  *
 672  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 673  *
 674  * @since 1.19
 675  * @param array $urlParts URL parts, as output from wfParseUrl
 676  * @return string URL assembled from its component parts
 677  */
 678 function wfAssembleUrl( $urlParts ) {
 679         $result = '';
 680
 681         if ( isset( $urlParts['delimiter'] ) ) {
 682                 if ( isset( $urlParts['scheme'] ) ) {
 683                         $result .= $urlParts['scheme'];
 684                 }
 685
 686                 $result .= $urlParts['delimiter'];
 687         }
 688
 689         if ( isset( $urlParts['host'] ) ) {
 690                 if ( isset( $urlParts['user'] ) ) {
 691                         $result .= $urlParts['user'];
 692                         if ( isset( $urlParts['pass'] ) ) {
 693                                 $result .= ':' . $urlParts['pass'];
 694                         }
 695                         $result .= '@';
 696                 }
 697
 698                 $result .= $urlParts['host'];
 699
 700                 if ( isset( $urlParts['port'] ) ) {
 701                         $result .= ':' . $urlParts['port'];
 702                 }
 703         }
 704
 705         if ( isset( $urlParts['path'] ) ) {
 706                 $result .= $urlParts['path'];
 707         }
 708
 709         if ( isset( $urlParts['query'] ) ) {
 710                 $result .= '?' . $urlParts['query'];
 711         }
 712
 713         if ( isset( $urlParts['fragment'] ) ) {
 714                 $result .= '#' . $urlParts['fragment'];
 715         }
 716
 717         return $result;
 718 }
 719
 720 /**
 721  * Remove all dot-segments in the provided URL path.  For example,
 722  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 723  * RFC3986 section 5.2.4.
 724  *
 725  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 726  *
 727  * @param string $urlPath URL path, potentially containing dot-segments
 728  * @return string URL path with all dot-segments removed
 729  */
 730 function wfRemoveDotSegments( $urlPath ) {
 731         $output = '';
 732         $inputOffset = 0;
 733         $inputLength = strlen( $urlPath );
 734
 735         while ( $inputOffset < $inputLength ) {
 736                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 737                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 738                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 739                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 740                 $trimOutput = false;
 741
 742                 if ( $prefixLengthTwo == './' ) {
 743                         # Step A, remove leading "./"
 744                         $inputOffset += 2;
 745                 } elseif ( $prefixLengthThree == '../' ) {
 746                         # Step A, remove leading "../"
 747                         $inputOffset += 3;
 748                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 749                         # Step B, replace leading "/.$" with "/"
 750                         $inputOffset += 1;
 751                         $urlPath[$inputOffset] = '/';
 752                 } elseif ( $prefixLengthThree == '/./' ) {
 753                         # Step B, replace leading "/./" with "/"
 754                         $inputOffset += 2;
 755                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 756                         # Step C, replace leading "/..$" with "/" and
 757                         # remove last path component in output
 758                         $inputOffset += 2;
 759                         $urlPath[$inputOffset] = '/';
 760                         $trimOutput = true;
 761                 } elseif ( $prefixLengthFour == '/../' ) {
 762                         # Step C, replace leading "/../" with "/" and
 763                         # remove last path component in output
 764                         $inputOffset += 3;
 765                         $trimOutput = true;
 766                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 767                         # Step D, remove "^.$"
 768                         $inputOffset += 1;
 769                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 770                         # Step D, remove "^..$"
 771                         $inputOffset += 2;
 772                 } else {
 773                         # Step E, move leading path segment to output
 774                         if ( $prefixLengthOne == '/' ) {
 775                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 776                         } else {
 777                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 778                         }
 779                         if ( $slashPos === false ) {
 780                                 $output .= substr( $urlPath, $inputOffset );
 781                                 $inputOffset = $inputLength;
 782                         } else {
 783                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 784                                 $inputOffset += $slashPos - $inputOffset;
 785                         }
 786                 }
 787
 788                 if ( $trimOutput ) {
 789                         $slashPos = strrpos( $output, '/' );
 790                         if ( $slashPos === false ) {
 791                                 $output = '';
 792                         } else {
 793                                 $output = substr( $output, 0, $slashPos );
 794                         }
 795                 }
 796         }
 797
 798         return $output;
 799 }
 800
 801 /**
 802  * Returns a regular expression of url protocols
 803  *
 804  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 805  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 806  * @return string
 807  */
 808 function wfUrlProtocols( $includeProtocolRelative = true ) {
 809         global $wgUrlProtocols;
 810
 811         // Cache return values separately based on $includeProtocolRelative
 812         static $withProtRel = null, $withoutProtRel = null;
 813         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 814         if ( !is_null( $cachedValue ) ) {
 815                 return $cachedValue;
 816         }
 817
 818         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 819         // with LocalSettings files from 1.5
 820         if ( is_array( $wgUrlProtocols ) ) {
 821                 $protocols = array();
 822                 foreach ( $wgUrlProtocols as $protocol ) {
 823                         // Filter out '//' if !$includeProtocolRelative
 824                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 825                                 $protocols[] = preg_quote( $protocol, '/' );
 826                         }
 827                 }
 828
 829                 $retval = implode( '|', $protocols );
 830         } else {
 831                 // Ignore $includeProtocolRelative in this case
 832                 // This case exists for pre-1.6 compatibility, and we can safely assume
 833                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 834                 // URLs weren't supported until 1.18
 835                 $retval = $wgUrlProtocols;
 836         }
 837
 838         // Cache return value
 839         if ( $includeProtocolRelative ) {
 840                 $withProtRel = $retval;
 841         } else {
 842                 $withoutProtRel = $retval;
 843         }
 844         return $retval;
 845 }
 846
 847 /**
 848  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 849  * you need a regex that matches all URL protocols but does not match protocol-
 850  * relative URLs
 851  * @return string
 852  */
 853 function wfUrlProtocolsWithoutProtRel() {
 854         return wfUrlProtocols( false );
 855 }
 856
 857 /**
 858  * parse_url() work-alike, but non-broken.  Differences:
 859  *
 860  * 1) Does not raise warnings on bad URLs (just returns false).
 861  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 862  *    protocol-relative URLs) correctly.
 863  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 864  *
 865  * @param string $url A URL to parse
 866  * @return string[] Bits of the URL in an associative array, per PHP docs
 867  */
 868 function wfParseUrl( $url ) {
 869         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 870
 871         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 872         // bad that the easiest way to handle them is to just prepend 'http:' and
 873         // strip the protocol out later.
 874         $wasRelative = substr( $url, 0, 2 ) == '//';
 875         if ( $wasRelative ) {
 876                 $url = "http:$url";
 877         }
 878         MediaWiki\suppressWarnings();
 879         $bits = parse_url( $url );
 880         MediaWiki\restoreWarnings();
 881         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 882         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 883         if ( !$bits || !isset( $bits['scheme'] ) ) {
 884                 return false;
 885         }
 886
 887         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 888         $bits['scheme'] = strtolower( $bits['scheme'] );
 889
 890         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 891         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 892                 $bits['delimiter'] = '://';
 893         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 894                 $bits['delimiter'] = ':';
 895                 // parse_url detects for news: and mailto: the host part of an url as path
 896                 // We have to correct this wrong detection
 897                 if ( isset( $bits['path'] ) ) {
 898                         $bits['host'] = $bits['path'];
 899                         $bits['path'] = '';
 900                 }
 901         } else {
 902                 return false;
 903         }
 904
 905         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 906         if ( !isset( $bits['host'] ) ) {
 907                 $bits['host'] = '';
 908
 909                 // bug 45069
 910                 if ( isset( $bits['path'] ) ) {
 911                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 912                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 913                                 $bits['path'] = '/' . $bits['path'];
 914                         }
 915                 } else {
 916                         $bits['path'] = '';
 917                 }
 918         }
 919
 920         // If the URL was protocol-relative, fix scheme and delimiter
 921         if ( $wasRelative ) {
 922                 $bits['scheme'] = '';
 923                 $bits['delimiter'] = '//';
 924         }
 925         return $bits;
 926 }
 927
 928 /**
 929  * Take a URL, make sure it's expanded to fully qualified, and replace any
 930  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 931  * for more compact display and legibility for local audiences.
 932  *
 933  * @todo handle punycode domains too
 934  *
 935  * @param string $url
 936  * @return string
 937  */
 938 function wfExpandIRI( $url ) {
 939         return preg_replace_callback(
 940                 '/((?:%[89A-F][0-9A-F])+)/i',
 941                 'wfExpandIRI_callback',
 942                 wfExpandUrl( $url )
 943         );
 944 }
 945
 946 /**
 947  * Private callback for wfExpandIRI
 948  * @param array $matches
 949  * @return string
 950  */
 951 function wfExpandIRI_callback( $matches ) {
 952         return urldecode( $matches[1] );
 953 }
 954
 955 /**
 956  * Make URL indexes, appropriate for the el_index field of externallinks.
 957  *
 958  * @param string $url
 959  * @return array
 960  */
 961 function wfMakeUrlIndexes( $url ) {
 962         $bits = wfParseUrl( $url );
 963
 964         // Reverse the labels in the hostname, convert to lower case
 965         // For emails reverse domainpart only
 966         if ( $bits['scheme'] == 'mailto' ) {
 967                 $mailparts = explode( '@', $bits['host'], 2 );
 968                 if ( count( $mailparts ) === 2 ) {
 969                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 970                 } else {
 971                         // No domain specified, don't mangle it
 972                         $domainpart = '';
 973                 }
 974                 $reversedHost = $domainpart . '@' . $mailparts[0];
 975         } else {
 976                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 977         }
 978         // Add an extra dot to the end
 979         // Why? Is it in wrong place in mailto links?
 980         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 981                 $reversedHost .= '.';
 982         }
 983         // Reconstruct the pseudo-URL
 984         $prot = $bits['scheme'];
 985         $index = $prot . $bits['delimiter'] . $reversedHost;
 986         // Leave out user and password. Add the port, path, query and fragment
 987         if ( isset( $bits['port'] ) ) {
 988                 $index .= ':' . $bits['port'];
 989         }
 990         if ( isset( $bits['path'] ) ) {
 991                 $index .= $bits['path'];
 992         } else {
 993                 $index .= '/';
 994         }
 995         if ( isset( $bits['query'] ) ) {
 996                 $index .= '?' . $bits['query'];
 997         }
 998         if ( isset( $bits['fragment'] ) ) {
 999                 $index .= '#' . $bits['fragment'];
1000         }
1001
1002         if ( $prot == '' ) {
1003                 return array( "http:$index", "https:$index" );
1004         } else {
1005                 return array( $index );
1006         }
1007 }
1008
1009 /**
1010  * Check whether a given URL has a domain that occurs in a given set of domains
1011  * @param string $url URL
1012  * @param array $domains Array of domains (strings)
1013  * @return bool True if the host part of $url ends in one of the strings in $domains
1014  */
1015 function wfMatchesDomainList( $url, $domains ) {
1016         $bits = wfParseUrl( $url );
1017         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1018                 $host = '.' . $bits['host'];
1019                 foreach ( (array)$domains as $domain ) {
1020                         $domain = '.' . $domain;
1021                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1022                                 return true;
1023                         }
1024                 }
1025         }
1026         return false;
1027 }
1028
1029 /**
1030  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1031  * In normal operation this is a NOP.
1032  *
1033  * Controlling globals:
1034  * $wgDebugLogFile - points to the log file
1035  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1036  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1037  *
1038  * @since 1.25 support for additional context data
1039  *
1040  * @param string $text
1041  * @param string|bool $dest Destination of the message:
1042  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1043  *     - 'private': excluded from HTML output
1044  *   For backward compatibility, it can also take a boolean:
1045  *     - true: same as 'all'
1046  *     - false: same as 'private'
1047  * @param array $context Additional logging context data
1048  */
1049 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1050         global $wgDebugRawPage, $wgDebugLogPrefix;
1051         global $wgDebugTimestamps, $wgRequestTime;
1052
1053         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1054                 return;
1055         }
1056
1057         $text = trim( $text );
1058
1059         if ( $wgDebugTimestamps ) {
1060                 $context['seconds_elapsed'] = sprintf(
1061                         '%6.4f',
1062                         microtime( true ) - $wgRequestTime
1063                 );
1064                 $context['memory_used'] = sprintf(
1065                         '%5.1fM',
1066                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1067                 );
1068         }
1069
1070         if ( $wgDebugLogPrefix !== '' ) {
1071                 $context['prefix'] = $wgDebugLogPrefix;
1072         }
1073         $context['private'] = ( $dest === false || $dest === 'private' );
1074
1075         $logger = LoggerFactory::getInstance( 'wfDebug' );
1076         $logger->debug( $text, $context );
1077 }
1078
1079 /**
1080  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1081  * @return bool
1082  */
1083 function wfIsDebugRawPage() {
1084         static $cache;
1085         if ( $cache !== null ) {
1086                 return $cache;
1087         }
1088         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1089         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1090                 || (
1091                         isset( $_SERVER['SCRIPT_NAME'] )
1092                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1093                 )
1094         ) {
1095                 $cache = true;
1096         } else {
1097                 $cache = false;
1098         }
1099         return $cache;
1100 }
1101
1102 /**
1103  * Send a line giving PHP memory usage.
1104  *
1105  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1106  */
1107 function wfDebugMem( $exact = false ) {
1108         $mem = memory_get_usage();
1109         if ( !$exact ) {
1110                 $mem = floor( $mem / 1024 ) . ' KiB';
1111         } else {
1112                 $mem .= ' B';
1113         }
1114         wfDebug( "Memory usage: $mem\n" );
1115 }
1116
1117 /**
1118  * Send a line to a supplementary debug log file, if configured, or main debug
1119  * log if not.
1120  *
1121  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1122  * a string filename or an associative array mapping 'destination' to the
1123  * desired filename. The associative array may also contain a 'sample' key
1124  * with an integer value, specifying a sampling factor. Sampled log events
1125  * will be emitted with a 1 in N random chance.
1126  *
1127  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1128  * @since 1.25 support for additional context data
1129  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1130  *
1131  * @param string $logGroup
1132  * @param string $text
1133  * @param string|bool $dest Destination of the message:
1134  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1135  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1136  *       discarded otherwise
1137  *   For backward compatibility, it can also take a boolean:
1138  *     - true: same as 'all'
1139  *     - false: same as 'private'
1140  * @param array $context Additional logging context data
1141  */
1142 function wfDebugLog(
1143         $logGroup, $text, $dest = 'all', array $context = array()
1144 ) {
1145         $text = trim( $text );
1146
1147         $logger = LoggerFactory::getInstance( $logGroup );
1148         $context['private'] = ( $dest === false || $dest === 'private' );
1149         $logger->info( $text, $context );
1150 }
1151
1152 /**
1153  * Log for database errors
1154  *
1155  * @since 1.25 support for additional context data
1156  *
1157  * @param string $text Database error message.
1158  * @param array $context Additional logging context data
1159  */
1160 function wfLogDBError( $text, array $context = array() ) {
1161         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1162         $logger->error( trim( $text ), $context );
1163 }
1164
1165 /**
1166  * Throws a warning that $function is deprecated
1167  *
1168  * @param string $function
1169  * @param string|bool $version Version of MediaWiki that the function
1170  *    was deprecated in (Added in 1.19).
1171  * @param string|bool $component Added in 1.19.
1172  * @param int $callerOffset How far up the call stack is the original
1173  *    caller. 2 = function that called the function that called
1174  *    wfDeprecated (Added in 1.20)
1175  *
1176  * @return null
1177  */
1178 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1179         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1180 }
1181
1182 /**
1183  * Send a warning either to the debug log or in a PHP error depending on
1184  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1185  *
1186  * @param string $msg Message to send
1187  * @param int $callerOffset Number of items to go back in the backtrace to
1188  *        find the correct caller (1 = function calling wfWarn, ...)
1189  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1190  *        only used when $wgDevelopmentWarnings is true
1191  */
1192 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1193         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1194 }
1195
1196 /**
1197  * Send a warning as a PHP error and the debug log. This is intended for logging
1198  * warnings in production. For logging development warnings, use WfWarn instead.
1199  *
1200  * @param string $msg Message to send
1201  * @param int $callerOffset Number of items to go back in the backtrace to
1202  *        find the correct caller (1 = function calling wfLogWarning, ...)
1203  * @param int $level PHP error level; defaults to E_USER_WARNING
1204  */
1205 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1206         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1207 }
1208
1209 /**
1210  * Log to a file without getting "file size exceeded" signals.
1211  *
1212  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1213  * send lines to the specified port, prefixed by the specified prefix and a space.
1214  * @since 1.25 support for additional context data
1215  *
1216  * @param string $text
1217  * @param string $file Filename
1218  * @param array $context Additional logging context data
1219  * @throws MWException
1220  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1221  */
1222 function wfErrorLog( $text, $file, array $context = array() ) {
1223         wfDeprecated( __METHOD__, '1.25' );
1224         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1225         $context['destination'] = $file;
1226         $logger->info( trim( $text ), $context );
1227 }
1228
1229 /**
1230  * @todo document
1231  */
1232 function wfLogProfilingData() {
1233         global $wgDebugLogGroups, $wgDebugRawPage;
1234
1235         $context = RequestContext::getMain();
1236         $request = $context->getRequest();
1237
1238         $profiler = Profiler::instance();
1239         $profiler->setContext( $context );
1240         $profiler->logData();
1241
1242         $config = $context->getConfig();
1243         if ( $config->get( 'StatsdServer' ) ) {
1244                 try {
1245                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1246                         $statsdHost = $statsdServer[0];
1247                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1248                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1249                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1250                         $statsdClient->send( $context->getStats()->getBuffer() );
1251                 } catch ( Exception $ex ) {
1252                         MWExceptionHandler::logException( $ex );
1253                 }
1254         }
1255
1256         # Profiling must actually be enabled...
1257         if ( $profiler instanceof ProfilerStub ) {
1258                 return;
1259         }
1260
1261         if ( isset( $wgDebugLogGroups['profileoutput'] )
1262                 && $wgDebugLogGroups['profileoutput'] === false
1263         ) {
1264                 // Explicitly disabled
1265                 return;
1266         }
1267         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1268                 return;
1269         }
1270
1271         $ctx = array( 'elapsed' => $request->getElapsedTime() );
1272         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1273                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1274         }
1275         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1276                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1277         }
1278         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1279                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1280         }
1281         if ( isset( $ctx['forwarded_for'] ) ||
1282                 isset( $ctx['client_ip'] ) ||
1283                 isset( $ctx['from'] ) ) {
1284                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1285         }
1286
1287         // Don't load $wgUser at this late stage just for statistics purposes
1288         // @todo FIXME: We can detect some anons even if it is not loaded.
1289         // See User::getId()
1290         $user = $context->getUser();
1291         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1292
1293         // Command line script uses a FauxRequest object which does not have
1294         // any knowledge about an URL and throw an exception instead.
1295         try {
1296                 $ctx['url'] = urldecode( $request->getRequestURL() );
1297         } catch ( Exception $ignored ) {
1298                 // no-op
1299         }
1300
1301         $ctx['output'] = $profiler->getOutput();
1302
1303         $log = LoggerFactory::getInstance( 'profileoutput' );
1304         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1305 }
1306
1307 /**
1308  * Increment a statistics counter
1309  *
1310  * @param string $key
1311  * @param int $count
1312  * @return void
1313  */
1314 function wfIncrStats( $key, $count = 1 ) {
1315         $stats = RequestContext::getMain()->getStats();
1316         $stats->updateCount( $key, $count );
1317 }
1318
1319 /**
1320  * Check whether the wiki is in read-only mode.
1321  *
1322  * @return bool
1323  */
1324 function wfReadOnly() {
1325         return wfReadOnlyReason() !== false;
1326 }
1327
1328 /**
1329  * Check if the site is in read-only mode and return the message if so
1330  *
1331  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1332  * for slave lag. This may result in DB_SLAVE connection being made.
1333  *
1334  * @return string|bool String when in read-only mode; false otherwise
1335  */
1336 function wfReadOnlyReason() {
1337         $readOnly = wfConfiguredReadOnlyReason();
1338         if ( $readOnly !== false ) {
1339                 return $readOnly;
1340         }
1341
1342         static $lbReadOnly = null;
1343         if ( $lbReadOnly === null ) {
1344                 // Callers use this method to be aware that data presented to a user
1345                 // may be very stale and thus allowing submissions can be problematic.
1346                 $lbReadOnly = wfGetLB()->getReadOnlyReason();
1347         }
1348
1349         return $lbReadOnly;
1350 }
1351
1352 /**
1353  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1354  *
1355  * @return string|bool String when in read-only mode; false otherwise
1356  * @since 1.27
1357  */
1358 function wfConfiguredReadOnlyReason() {
1359         global $wgReadOnly, $wgReadOnlyFile;
1360
1361         if ( $wgReadOnly === null ) {
1362                 // Set $wgReadOnly for faster access next time
1363                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1364                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1365                 } else {
1366                         $wgReadOnly = false;
1367                 }
1368         }
1369
1370         return $wgReadOnly;
1371 }
1372
1373 /**
1374  * Return a Language object from $langcode
1375  *
1376  * @param Language|string|bool $langcode Either:
1377  *                  - a Language object
1378  *                  - code of the language to get the message for, if it is
1379  *                    a valid code create a language for that language, if
1380  *                    it is a string but not a valid code then make a basic
1381  *                    language object
1382  *                  - a boolean: if it's false then use the global object for
1383  *                    the current user's language (as a fallback for the old parameter
1384  *                    functionality), or if it is true then use global object
1385  *                    for the wiki's content language.
1386  * @return Language
1387  */
1388 function wfGetLangObj( $langcode = false ) {
1389         # Identify which language to get or create a language object for.
1390         # Using is_object here due to Stub objects.
1391         if ( is_object( $langcode ) ) {
1392                 # Great, we already have the object (hopefully)!
1393                 return $langcode;
1394         }
1395
1396         global $wgContLang, $wgLanguageCode;
1397         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1398                 # $langcode is the language code of the wikis content language object.
1399                 # or it is a boolean and value is true
1400                 return $wgContLang;
1401         }
1402
1403         global $wgLang;
1404         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1405                 # $langcode is the language code of user language object.
1406                 # or it was a boolean and value is false
1407                 return $wgLang;
1408         }
1409
1410         $validCodes = array_keys( Language::fetchLanguageNames() );
1411         if ( in_array( $langcode, $validCodes ) ) {
1412                 # $langcode corresponds to a valid language.
1413                 return Language::factory( $langcode );
1414         }
1415
1416         # $langcode is a string, but not a valid language code; use content language.
1417         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1418         return $wgContLang;
1419 }
1420
1421 /**
1422  * This is the function for getting translated interface messages.
1423  *
1424  * @see Message class for documentation how to use them.
1425  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1426  *
1427  * This function replaces all old wfMsg* functions.
1428  *
1429  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1430  * @param mixed $params,... Normal message parameters
1431  * @return Message
1432  *
1433  * @since 1.17
1434  *
1435  * @see Message::__construct
1436  */
1437 function wfMessage( $key /*...*/ ) {
1438         $params = func_get_args();
1439         array_shift( $params );
1440         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1441                 $params = $params[0];
1442         }
1443         return new Message( $key, $params );
1444 }
1445
1446 /**
1447  * This function accepts multiple message keys and returns a message instance
1448  * for the first message which is non-empty. If all messages are empty then an
1449  * instance of the first message key is returned.
1450  *
1451  * @param string|string[] $keys,... Message keys
1452  * @return Message
1453  *
1454  * @since 1.18
1455  *
1456  * @see Message::newFallbackSequence
1457  */
1458 function wfMessageFallback( /*...*/ ) {
1459         $args = func_get_args();
1460         return call_user_func_array( 'Message::newFallbackSequence', $args );
1461 }
1462
1463 /**
1464  * Get a message from anywhere, for the current user language.
1465  *
1466  * Use wfMsgForContent() instead if the message should NOT
1467  * change depending on the user preferences.
1468  *
1469  * @deprecated since 1.18
1470  *
1471  * @param string $key Lookup key for the message, usually
1472  *    defined in languages/Language.php
1473  *
1474  * Parameters to the message, which can be used to insert variable text into
1475  * it, can be passed to this function in the following formats:
1476  * - One per argument, starting at the second parameter
1477  * - As an array in the second parameter
1478  * These are not shown in the function definition.
1479  *
1480  * @return string
1481  */
1482 function wfMsg( $key ) {
1483         wfDeprecated( __METHOD__, '1.21' );
1484
1485         $args = func_get_args();
1486         array_shift( $args );
1487         return wfMsgReal( $key, $args );
1488 }
1489
1490 /**
1491  * Same as above except doesn't transform the message
1492  *
1493  * @deprecated since 1.18
1494  *
1495  * @param string $key
1496  * @return string
1497  */
1498 function wfMsgNoTrans( $key ) {
1499         wfDeprecated( __METHOD__, '1.21' );
1500
1501         $args = func_get_args();
1502         array_shift( $args );
1503         return wfMsgReal( $key, $args, true, false, false );
1504 }
1505
1506 /**
1507  * Get a message from anywhere, for the current global language
1508  * set with $wgLanguageCode.
1509  *
1510  * Use this if the message should NOT change dependent on the
1511  * language set in the user's preferences. This is the case for
1512  * most text written into logs, as well as link targets (such as
1513  * the name of the copyright policy page). Link titles, on the
1514  * other hand, should be shown in the UI language.
1515  *
1516  * Note that MediaWiki allows users to change the user interface
1517  * language in their preferences, but a single installation
1518  * typically only contains content in one language.
1519  *
1520  * Be wary of this distinction: If you use wfMsg() where you should
1521  * use wfMsgForContent(), a user of the software may have to
1522  * customize potentially hundreds of messages in
1523  * order to, e.g., fix a link in every possible language.
1524  *
1525  * @deprecated since 1.18
1526  *
1527  * @param string $key Lookup key for the message, usually
1528  *     defined in languages/Language.php
1529  * @return string
1530  */
1531 function wfMsgForContent( $key ) {
1532         wfDeprecated( __METHOD__, '1.21' );
1533
1534         global $wgForceUIMsgAsContentMsg;
1535         $args = func_get_args();
1536         array_shift( $args );
1537         $forcontent = true;
1538         if ( is_array( $wgForceUIMsgAsContentMsg )
1539                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1540         ) {
1541                 $forcontent = false;
1542         }
1543         return wfMsgReal( $key, $args, true, $forcontent );
1544 }
1545
1546 /**
1547  * Same as above except doesn't transform the message
1548  *
1549  * @deprecated since 1.18
1550  *
1551  * @param string $key
1552  * @return string
1553  */
1554 function wfMsgForContentNoTrans( $key ) {
1555         wfDeprecated( __METHOD__, '1.21' );
1556
1557         global $wgForceUIMsgAsContentMsg;
1558         $args = func_get_args();
1559         array_shift( $args );
1560         $forcontent = true;
1561         if ( is_array( $wgForceUIMsgAsContentMsg )
1562                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1563         ) {
1564                 $forcontent = false;
1565         }
1566         return wfMsgReal( $key, $args, true, $forcontent, false );
1567 }
1568
1569 /**
1570  * Really get a message
1571  *
1572  * @deprecated since 1.18
1573  *
1574  * @param string $key Key to get.
1575  * @param array $args
1576  * @param bool $useDB
1577  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1578  * @param bool $transform Whether or not to transform the message.
1579  * @return string The requested message.
1580  */
1581 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1582         wfDeprecated( __METHOD__, '1.21' );
1583
1584         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1585         $message = wfMsgReplaceArgs( $message, $args );
1586         return $message;
1587 }
1588
1589 /**
1590  * Fetch a message string value, but don't replace any keys yet.
1591  *
1592  * @deprecated since 1.18
1593  *
1594  * @param string $key
1595  * @param bool $useDB
1596  * @param string|bool $langCode Code of the language to get the message for, or
1597  *   behaves as a content language switch if it is a boolean.
1598  * @param bool $transform Whether to parse magic words, etc.
1599  * @return string
1600  */
1601 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1602         wfDeprecated( __METHOD__, '1.21' );
1603
1604         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1605
1606         $cache = MessageCache::singleton();
1607         $message = $cache->get( $key, $useDB, $langCode );
1608         if ( $message === false ) {
1609                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1610         } elseif ( $transform ) {
1611                 $message = $cache->transform( $message );
1612         }
1613         return $message;
1614 }
1615
1616 /**
1617  * Replace message parameter keys on the given formatted output.
1618  *
1619  * @param string $message
1620  * @param array $args
1621  * @return string
1622  * @private
1623  */
1624 function wfMsgReplaceArgs( $message, $args ) {
1625         # Fix windows line-endings
1626         # Some messages are split with explode("\n", $msg)
1627         $message = str_replace( "\r", '', $message );
1628
1629         // Replace arguments
1630         if ( count( $args ) ) {
1631                 if ( is_array( $args[0] ) ) {
1632                         $args = array_values( $args[0] );
1633                 }
1634                 $replacementKeys = array();
1635                 foreach ( $args as $n => $param ) {
1636                         $replacementKeys['$' . ( $n + 1 )] = $param;
1637                 }
1638                 $message = strtr( $message, $replacementKeys );
1639         }
1640
1641         return $message;
1642 }
1643
1644 /**
1645  * Return an HTML-escaped version of a message.
1646  * Parameter replacements, if any, are done *after* the HTML-escaping,
1647  * so parameters may contain HTML (eg links or form controls). Be sure
1648  * to pre-escape them if you really do want plaintext, or just wrap
1649  * the whole thing in htmlspecialchars().
1650  *
1651  * @deprecated since 1.18
1652  *
1653  * @param string $key
1654  * @param string $args,... Parameters
1655  * @return string
1656  */
1657 function wfMsgHtml( $key ) {
1658         wfDeprecated( __METHOD__, '1.21' );
1659
1660         $args = func_get_args();
1661         array_shift( $args );
1662         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1663 }
1664
1665 /**
1666  * Return an HTML version of message
1667  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1668  * so parameters may contain HTML (eg links or form controls). Be sure
1669  * to pre-escape them if you really do want plaintext, or just wrap
1670  * the whole thing in htmlspecialchars().
1671  *
1672  * @deprecated since 1.18
1673  *
1674  * @param string $key
1675  * @param string $args,... Parameters
1676  * @return string
1677  */
1678 function wfMsgWikiHtml( $key ) {
1679         wfDeprecated( __METHOD__, '1.21' );
1680
1681         $args = func_get_args();
1682         array_shift( $args );
1683         return wfMsgReplaceArgs(
1684                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1685                 /* can't be set to false */ true, /* interface */ true )->getText(),
1686                 $args );
1687 }
1688
1689 /**
1690  * Returns message in the requested format
1691  *
1692  * @deprecated since 1.18
1693  *
1694  * @param string $key Key of the message
1695  * @param array $options Processing rules.
1696  *   Can take the following options:
1697  *     parse: parses wikitext to HTML
1698  *     parseinline: parses wikitext to HTML and removes the surrounding
1699  *       p's added by parser or tidy
1700  *     escape: filters message through htmlspecialchars
1701  *     escapenoentities: same, but allows entity references like &#160; through
1702  *     replaceafter: parameters are substituted after parsing or escaping
1703  *     parsemag: transform the message using magic phrases
1704  *     content: fetch message for content language instead of interface
1705  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1706  *     language: Language object or language code to fetch message for
1707  *       (overridden by content).
1708  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1709  *
1710  * @return string
1711  */
1712 function wfMsgExt( $key, $options ) {
1713         wfDeprecated( __METHOD__, '1.21' );
1714
1715         $args = func_get_args();
1716         array_shift( $args );
1717         array_shift( $args );
1718         $options = (array)$options;
1719         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1720                 'parsemag', 'content' );
1721
1722         foreach ( $options as $arrayKey => $option ) {
1723                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1724                         // An unknown index, neither numeric nor "language"
1725                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1726                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1727                         // A numeric index with unknown value
1728                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1729                 }
1730         }
1731
1732         if ( in_array( 'content', $options, true ) ) {
1733                 $forContent = true;
1734                 $langCode = true;
1735                 $langCodeObj = null;
1736         } elseif ( array_key_exists( 'language', $options ) ) {
1737                 $forContent = false;
1738                 $langCode = wfGetLangObj( $options['language'] );
1739                 $langCodeObj = $langCode;
1740         } else {
1741                 $forContent = false;
1742                 $langCode = false;
1743                 $langCodeObj = null;
1744         }
1745
1746         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1747
1748         if ( !in_array( 'replaceafter', $options, true ) ) {
1749                 $string = wfMsgReplaceArgs( $string, $args );
1750         }
1751
1752         $messageCache = MessageCache::singleton();
1753         $parseInline = in_array( 'parseinline', $options, true );
1754         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1755                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1756                 if ( $string instanceof ParserOutput ) {
1757                         $string = $string->getText();
1758                 }
1759
1760                 if ( $parseInline ) {
1761                         $string = Parser::stripOuterParagraph( $string );
1762                 }
1763         } elseif ( in_array( 'parsemag', $options, true ) ) {
1764                 $string = $messageCache->transform( $string,
1765                                 !$forContent, $langCodeObj );
1766         }
1767
1768         if ( in_array( 'escape', $options, true ) ) {
1769                 $string = htmlspecialchars( $string );
1770         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1771                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1772         }
1773
1774         if ( in_array( 'replaceafter', $options, true ) ) {
1775                 $string = wfMsgReplaceArgs( $string, $args );
1776         }
1777
1778         return $string;
1779 }
1780
1781 /**
1782  * Fetch server name for use in error reporting etc.
1783  * Use real server name if available, so we know which machine
1784  * in a server farm generated the current page.
1785  *
1786  * @return string
1787  */
1788 function wfHostname() {
1789         static $host;
1790         if ( is_null( $host ) ) {
1791
1792                 # Hostname overriding
1793                 global $wgOverrideHostname;
1794                 if ( $wgOverrideHostname !== false ) {
1795                         # Set static and skip any detection
1796                         $host = $wgOverrideHostname;
1797                         return $host;
1798                 }
1799
1800                 if ( function_exists( 'posix_uname' ) ) {
1801                         // This function not present on Windows
1802                         $uname = posix_uname();
1803                 } else {
1804                         $uname = false;
1805                 }
1806                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1807                         $host = $uname['nodename'];
1808                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1809                         # Windows computer name
1810                         $host = getenv( 'COMPUTERNAME' );
1811                 } else {
1812                         # This may be a virtual server.
1813                         $host = $_SERVER['SERVER_NAME'];
1814                 }
1815         }
1816         return $host;
1817 }
1818
1819 /**
1820  * Returns a script tag that stores the amount of time it took MediaWiki to
1821  * handle the request in milliseconds as 'wgBackendResponseTime'.
1822  *
1823  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1824  * hostname of the server handling the request.
1825  *
1826  * @return string
1827  */
1828 function wfReportTime() {
1829         global $wgRequestTime, $wgShowHostnames;
1830
1831         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1832         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1833         if ( $wgShowHostnames ) {
1834                 $reportVars['wgHostname'] = wfHostname();
1835         }
1836         return Skin::makeVariablesScript( $reportVars );
1837 }
1838
1839 /**
1840  * Safety wrapper for debug_backtrace().
1841  *
1842  * Will return an empty array if debug_backtrace is disabled, otherwise
1843  * the output from debug_backtrace() (trimmed).
1844  *
1845  * @param int $limit This parameter can be used to limit the number of stack frames returned
1846  *
1847  * @return array Array of backtrace information
1848  */
1849 function wfDebugBacktrace( $limit = 0 ) {
1850         static $disabled = null;
1851
1852         if ( is_null( $disabled ) ) {
1853                 $disabled = !function_exists( 'debug_backtrace' );
1854                 if ( $disabled ) {
1855                         wfDebug( "debug_backtrace() is disabled\n" );
1856                 }
1857         }
1858         if ( $disabled ) {
1859                 return array();
1860         }
1861
1862         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1863                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1864         } else {
1865                 return array_slice( debug_backtrace(), 1 );
1866         }
1867 }
1868
1869 /**
1870  * Get a debug backtrace as a string
1871  *
1872  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1873  *   Defaults to $wgCommandLineMode if unset.
1874  * @return string
1875  * @since 1.25 Supports $raw parameter.
1876  */
1877 function wfBacktrace( $raw = null ) {
1878         global $wgCommandLineMode;
1879
1880         if ( $raw === null ) {
1881                 $raw = $wgCommandLineMode;
1882         }
1883
1884         if ( $raw ) {
1885                 $frameFormat = "%s line %s calls %s()\n";
1886                 $traceFormat = "%s";
1887         } else {
1888                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1889                 $traceFormat = "<ul>\n%s</ul>\n";
1890         }
1891
1892         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1893                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1894                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1895                 $call = $frame['function'];
1896                 if ( !empty( $frame['class'] ) ) {
1897                         $call = $frame['class'] . $frame['type'] . $call;
1898                 }
1899                 return sprintf( $frameFormat, $file, $line, $call );
1900         }, wfDebugBacktrace() );
1901
1902         return sprintf( $traceFormat, implode( '', $frames ) );
1903 }
1904
1905 /**
1906  * Get the name of the function which called this function
1907  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1908  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1909  * wfGetCaller( 3 ) is the parent of that.
1910  *
1911  * @param int $level
1912  * @return string
1913  */
1914 function wfGetCaller( $level = 2 ) {
1915         $backtrace = wfDebugBacktrace( $level + 1 );
1916         if ( isset( $backtrace[$level] ) ) {
1917                 return wfFormatStackFrame( $backtrace[$level] );
1918         } else {
1919                 return 'unknown';
1920         }
1921 }
1922
1923 /**
1924  * Return a string consisting of callers in the stack. Useful sometimes
1925  * for profiling specific points.
1926  *
1927  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1928  * @return string
1929  */
1930 function wfGetAllCallers( $limit = 3 ) {
1931         $trace = array_reverse( wfDebugBacktrace() );
1932         if ( !$limit || $limit > count( $trace ) - 1 ) {
1933                 $limit = count( $trace ) - 1;
1934         }
1935         $trace = array_slice( $trace, -$limit - 1, $limit );
1936         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1937 }
1938
1939 /**
1940  * Return a string representation of frame
1941  *
1942  * @param array $frame
1943  * @return string
1944  */
1945 function wfFormatStackFrame( $frame ) {
1946         if ( !isset( $frame['function'] ) ) {
1947                 return 'NO_FUNCTION_GIVEN';
1948         }
1949         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1950                 $frame['class'] . $frame['type'] . $frame['function'] :
1951                 $frame['function'];
1952 }
1953
1954 /* Some generic result counters, pulled out of SearchEngine */
1955
1956 /**
1957  * @todo document
1958  *
1959  * @param int $offset
1960  * @param int $limit
1961  * @return string
1962  */
1963 function wfShowingResults( $offset, $limit ) {
1964         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1965 }
1966
1967 /**
1968  * @todo document
1969  * @todo FIXME: We may want to blacklist some broken browsers
1970  *
1971  * @param bool $force
1972  * @return bool Whereas client accept gzip compression
1973  */
1974 function wfClientAcceptsGzip( $force = false ) {
1975         static $result = null;
1976         if ( $result === null || $force ) {
1977                 $result = false;
1978                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1979                         # @todo FIXME: We may want to blacklist some broken browsers
1980                         $m = array();
1981                         if ( preg_match(
1982                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1983                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1984                                         $m
1985                                 )
1986                         ) {
1987                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1988                                         $result = false;
1989                                         return $result;
1990                                 }
1991                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1992                                 $result = true;
1993                         }
1994                 }
1995         }
1996         return $result;
1997 }
1998
1999 /**
2000  * Escapes the given text so that it may be output using addWikiText()
2001  * without any linking, formatting, etc. making its way through. This
2002  * is achieved by substituting certain characters with HTML entities.
2003  * As required by the callers, "<nowiki>" is not used.
2004  *
2005  * @param string $text Text to be escaped
2006  * @return string
2007  */
2008 function wfEscapeWikiText( $text ) {
2009         static $repl = null, $repl2 = null;
2010         if ( $repl === null ) {
2011                 $repl = array(
2012                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2013                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2014                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2015                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2016                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2017                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2018                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2019                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2020                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2021                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2022                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2023                         '__' => '_&#95;', '://' => '&#58;//',
2024                 );
2025
2026                 // We have to catch everything "\s" matches in PCRE
2027                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2028                         $repl["$magic "] = "$magic&#32;";
2029                         $repl["$magic\t"] = "$magic&#9;";
2030                         $repl["$magic\r"] = "$magic&#13;";
2031                         $repl["$magic\n"] = "$magic&#10;";
2032                         $repl["$magic\f"] = "$magic&#12;";
2033                 }
2034
2035                 // And handle protocols that don't use "://"
2036                 global $wgUrlProtocols;
2037                 $repl2 = array();
2038                 foreach ( $wgUrlProtocols as $prot ) {
2039                         if ( substr( $prot, -1 ) === ':' ) {
2040                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2041                         }
2042                 }
2043                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2044         }
2045         $text = substr( strtr( "\n$text", $repl ), 1 );
2046         $text = preg_replace( $repl2, '$1&#58;', $text );
2047         return $text;
2048 }
2049
2050 /**
2051  * Sets dest to source and returns the original value of dest
2052  * If source is NULL, it just returns the value, it doesn't set the variable
2053  * If force is true, it will set the value even if source is NULL
2054  *
2055  * @param mixed $dest
2056  * @param mixed $source
2057  * @param bool $force
2058  * @return mixed
2059  */
2060 function wfSetVar( &$dest, $source, $force = false ) {
2061         $temp = $dest;
2062         if ( !is_null( $source ) || $force ) {
2063                 $dest = $source;
2064         }
2065         return $temp;
2066 }
2067
2068 /**
2069  * As for wfSetVar except setting a bit
2070  *
2071  * @param int $dest
2072  * @param int $bit
2073  * @param bool $state
2074  *
2075  * @return bool
2076  */
2077 function wfSetBit( &$dest, $bit, $state = true ) {
2078         $temp = (bool)( $dest & $bit );
2079         if ( !is_null( $state ) ) {
2080                 if ( $state ) {
2081                         $dest |= $bit;
2082                 } else {
2083                         $dest &= ~$bit;
2084                 }
2085         }
2086         return $temp;
2087 }
2088
2089 /**
2090  * A wrapper around the PHP function var_export().
2091  * Either print it or add it to the regular output ($wgOut).
2092  *
2093  * @param mixed $var A PHP variable to dump.
2094  */
2095 function wfVarDump( $var ) {
2096         global $wgOut;
2097         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2098         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2099                 print $s;
2100         } else {
2101                 $wgOut->addHTML( $s );
2102         }
2103 }
2104
2105 /**
2106  * Provide a simple HTTP error.
2107  *
2108  * @param int|string $code
2109  * @param string $label
2110  * @param string $desc
2111  */
2112 function wfHttpError( $code, $label, $desc ) {
2113         global $wgOut;
2114         HttpStatus::header( $code );
2115         if ( $wgOut ) {
2116                 $wgOut->disable();
2117                 $wgOut->sendCacheControl();
2118         }
2119
2120         header( 'Content-type: text/html; charset=utf-8' );
2121         print '<!DOCTYPE html>' .
2122                 '<html><head><title>' .
2123                 htmlspecialchars( $label ) .
2124                 '</title></head><body><h1>' .
2125                 htmlspecialchars( $label ) .
2126                 '</h1><p>' .
2127                 nl2br( htmlspecialchars( $desc ) ) .
2128                 "</p></body></html>\n";
2129 }
2130
2131 /**
2132  * Clear away any user-level output buffers, discarding contents.
2133  *
2134  * Suitable for 'starting afresh', for instance when streaming
2135  * relatively large amounts of data without buffering, or wanting to
2136  * output image files without ob_gzhandler's compression.
2137  *
2138  * The optional $resetGzipEncoding parameter controls suppression of
2139  * the Content-Encoding header sent by ob_gzhandler; by default it
2140  * is left. See comments for wfClearOutputBuffers() for why it would
2141  * be used.
2142  *
2143  * Note that some PHP configuration options may add output buffer
2144  * layers which cannot be removed; these are left in place.
2145  *
2146  * @param bool $resetGzipEncoding
2147  */
2148 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2149         if ( $resetGzipEncoding ) {
2150                 // Suppress Content-Encoding and Content-Length
2151                 // headers from 1.10+s wfOutputHandler
2152                 global $wgDisableOutputCompression;
2153                 $wgDisableOutputCompression = true;
2154         }
2155         while ( $status = ob_get_status() ) {
2156                 if ( isset( $status['flags'] ) ) {
2157                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
2158                         $deleteable = ( $status['flags'] & $flags ) === $flags;
2159                 } elseif ( isset( $status['del'] ) ) {
2160                         $deleteable = $status['del'];
2161                 } else {
2162                         // Guess that any PHP-internal setting can't be removed.
2163                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
2164                 }
2165                 if ( !$deleteable ) {
2166                         // Give up, and hope the result doesn't break
2167                         // output behavior.
2168                         break;
2169                 }
2170                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
2171                         // Unit testing barrier to prevent this function from breaking PHPUnit.
2172                         break;
2173                 }
2174                 if ( !ob_end_clean() ) {
2175                         // Could not remove output buffer handler; abort now
2176                         // to avoid getting in some kind of infinite loop.
2177                         break;
2178                 }
2179                 if ( $resetGzipEncoding ) {
2180                         if ( $status['name'] == 'ob_gzhandler' ) {
2181                                 // Reset the 'Content-Encoding' field set by this handler
2182                                 // so we can start fresh.
2183                                 header_remove( 'Content-Encoding' );
2184                                 break;
2185                         }
2186                 }
2187         }
2188 }
2189
2190 /**
2191  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2192  *
2193  * Clear away output buffers, but keep the Content-Encoding header
2194  * produced by ob_gzhandler, if any.
2195  *
2196  * This should be used for HTTP 304 responses, where you need to
2197  * preserve the Content-Encoding header of the real result, but
2198  * also need to suppress the output of ob_gzhandler to keep to spec
2199  * and avoid breaking Firefox in rare cases where the headers and
2200  * body are broken over two packets.
2201  */
2202 function wfClearOutputBuffers() {
2203         wfResetOutputBuffers( false );
2204 }
2205
2206 /**
2207  * Converts an Accept-* header into an array mapping string values to quality
2208  * factors
2209  *
2210  * @param string $accept
2211  * @param string $def Default
2212  * @return float[] Associative array of string => float pairs
2213  */
2214 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2215         # No arg means accept anything (per HTTP spec)
2216         if ( !$accept ) {
2217                 return array( $def => 1.0 );
2218         }
2219
2220         $prefs = array();
2221
2222         $parts = explode( ',', $accept );
2223
2224         foreach ( $parts as $part ) {
2225                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2226                 $values = explode( ';', trim( $part ) );
2227                 $match = array();
2228                 if ( count( $values ) == 1 ) {
2229                         $prefs[$values[0]] = 1.0;
2230                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2231                         $prefs[$values[0]] = floatval( $match[1] );
2232                 }
2233         }
2234
2235         return $prefs;
2236 }
2237
2238 /**
2239  * Checks if a given MIME type matches any of the keys in the given
2240  * array. Basic wildcards are accepted in the array keys.
2241  *
2242  * Returns the matching MIME type (or wildcard) if a match, otherwise
2243  * NULL if no match.
2244  *
2245  * @param string $type
2246  * @param array $avail
2247  * @return string
2248  * @private
2249  */
2250 function mimeTypeMatch( $type, $avail ) {
2251         if ( array_key_exists( $type, $avail ) ) {
2252                 return $type;
2253         } else {
2254                 $parts = explode( '/', $type );
2255                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2256                         return $parts[0] . '/*';
2257                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2258                         return '*/*';
2259                 } else {
2260                         return null;
2261                 }
2262         }
2263 }
2264
2265 /**
2266  * Returns the 'best' match between a client's requested internet media types
2267  * and the server's list of available types. Each list should be an associative
2268  * array of type to preference (preference is a float between 0.0 and 1.0).
2269  * Wildcards in the types are acceptable.
2270  *
2271  * @param array $cprefs Client's acceptable type list
2272  * @param array $sprefs Server's offered types
2273  * @return string
2274  *
2275  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2276  * XXX: generalize to negotiate other stuff
2277  */
2278 function wfNegotiateType( $cprefs, $sprefs ) {
2279         $combine = array();
2280
2281         foreach ( array_keys( $sprefs ) as $type ) {
2282                 $parts = explode( '/', $type );
2283                 if ( $parts[1] != '*' ) {
2284                         $ckey = mimeTypeMatch( $type, $cprefs );
2285                         if ( $ckey ) {
2286                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2287                         }
2288                 }
2289         }
2290
2291         foreach ( array_keys( $cprefs ) as $type ) {
2292                 $parts = explode( '/', $type );
2293                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2294                         $skey = mimeTypeMatch( $type, $sprefs );
2295                         if ( $skey ) {
2296                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2297                         }
2298                 }
2299         }
2300
2301         $bestq = 0;
2302         $besttype = null;
2303
2304         foreach ( array_keys( $combine ) as $type ) {
2305                 if ( $combine[$type] > $bestq ) {
2306                         $besttype = $type;
2307                         $bestq = $combine[$type];
2308                 }
2309         }
2310
2311         return $besttype;
2312 }
2313
2314 /**
2315  * Reference-counted warning suppression
2316  *
2317  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
2318  * @param bool $end
2319  */
2320 function wfSuppressWarnings( $end = false ) {
2321         MediaWiki\suppressWarnings( $end );
2322 }
2323
2324 /**
2325  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
2326  * Restore error level to previous value
2327  */
2328 function wfRestoreWarnings() {
2329         MediaWiki\suppressWarnings( true );
2330 }
2331
2332 # Autodetect, convert and provide timestamps of various types
2333
2334 /**
2335  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2336  */
2337 define( 'TS_UNIX', 0 );
2338
2339 /**
2340  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2341  */
2342 define( 'TS_MW', 1 );
2343
2344 /**
2345  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2346  */
2347 define( 'TS_DB', 2 );
2348
2349 /**
2350  * RFC 2822 format, for E-mail and HTTP headers
2351  */
2352 define( 'TS_RFC2822', 3 );
2353
2354 /**
2355  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2356  *
2357  * This is used by Special:Export
2358  */
2359 define( 'TS_ISO_8601', 4 );
2360
2361 /**
2362  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2363  *
2364  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2365  *       DateTime tag and page 36 for the DateTimeOriginal and
2366  *       DateTimeDigitized tags.
2367  */
2368 define( 'TS_EXIF', 5 );
2369
2370 /**
2371  * Oracle format time.
2372  */
2373 define( 'TS_ORACLE', 6 );
2374
2375 /**
2376  * Postgres format time.
2377  */
2378 define( 'TS_POSTGRES', 7 );
2379
2380 /**
2381  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2382  */
2383 define( 'TS_ISO_8601_BASIC', 9 );
2384
2385 /**
2386  * Get a timestamp string in one of various formats
2387  *
2388  * @param mixed $outputtype A timestamp in one of the supported formats, the
2389  *   function will autodetect which format is supplied and act accordingly.
2390  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2391  * @return string|bool String / false The same date in the format specified in $outputtype or false
2392  */
2393 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2394         try {
2395                 $timestamp = new MWTimestamp( $ts );
2396                 return $timestamp->getTimestamp( $outputtype );
2397         } catch ( TimestampException $e ) {
2398                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2399                 return false;
2400         }
2401 }
2402
2403 /**
2404  * Return a formatted timestamp, or null if input is null.
2405  * For dealing with nullable timestamp columns in the database.
2406  *
2407  * @param int $outputtype
2408  * @param string $ts
2409  * @return string
2410  */
2411 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2412         if ( is_null( $ts ) ) {
2413                 return null;
2414         } else {
2415                 return wfTimestamp( $outputtype, $ts );
2416         }
2417 }
2418
2419 /**
2420  * Convenience function; returns MediaWiki timestamp for the present time.
2421  *
2422  * @return string
2423  */
2424 function wfTimestampNow() {
2425         # return NOW
2426         return wfTimestamp( TS_MW, time() );
2427 }
2428
2429 /**
2430  * Check if the operating system is Windows
2431  *
2432  * @return bool True if it's Windows, false otherwise.
2433  */
2434 function wfIsWindows() {
2435         static $isWindows = null;
2436         if ( $isWindows === null ) {
2437                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2438         }
2439         return $isWindows;
2440 }
2441
2442 /**
2443  * Check if we are running under HHVM
2444  *
2445  * @return bool
2446  */
2447 function wfIsHHVM() {
2448         return defined( 'HHVM_VERSION' );
2449 }
2450
2451 /**
2452  * Tries to get the system directory for temporary files. First
2453  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2454  * environment variables are then checked in sequence, and if none are
2455  * set try sys_get_temp_dir().
2456  *
2457  * NOTE: When possible, use instead the tmpfile() function to create
2458  * temporary files to avoid race conditions on file creation, etc.
2459  *
2460  * @return string
2461  */
2462 function wfTempDir() {
2463         global $wgTmpDirectory;
2464
2465         if ( $wgTmpDirectory !== false ) {
2466                 return $wgTmpDirectory;
2467         }
2468
2469         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2470
2471         foreach ( $tmpDir as $tmp ) {
2472                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2473                         return $tmp;
2474                 }
2475         }
2476         return sys_get_temp_dir();
2477 }
2478
2479 /**
2480  * Make directory, and make all parent directories if they don't exist
2481  *
2482  * @param string $dir Full path to directory to create
2483  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2484  * @param string $caller Optional caller param for debugging.
2485  * @throws MWException
2486  * @return bool
2487  */
2488 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2489         global $wgDirectoryMode;
2490
2491         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2492                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2493         }
2494
2495         if ( !is_null( $caller ) ) {
2496                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2497         }
2498
2499         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2500                 return true;
2501         }
2502
2503         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2504
2505         if ( is_null( $mode ) ) {
2506                 $mode = $wgDirectoryMode;
2507         }
2508
2509         // Turn off the normal warning, we're doing our own below
2510         MediaWiki\suppressWarnings();
2511         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2512         MediaWiki\restoreWarnings();
2513
2514         if ( !$ok ) {
2515                 // directory may have been created on another request since we last checked
2516                 if ( is_dir( $dir ) ) {
2517                         return true;
2518                 }
2519
2520                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2521                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2522         }
2523         return $ok;
2524 }
2525
2526 /**
2527  * Remove a directory and all its content.
2528  * Does not hide error.
2529  * @param string $dir
2530  */
2531 function wfRecursiveRemoveDir( $dir ) {
2532         wfDebug( __FUNCTION__ . "( $dir )\n" );
2533         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2534         if ( is_dir( $dir ) ) {
2535                 $objects = scandir( $dir );
2536                 foreach ( $objects as $object ) {
2537                         if ( $object != "." && $object != ".." ) {
2538                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2539                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2540                                 } else {
2541                                         unlink( $dir . '/' . $object );
2542                                 }
2543                         }
2544                 }
2545                 reset( $objects );
2546                 rmdir( $dir );
2547         }
2548 }
2549
2550 /**
2551  * @param int $nr The number to format
2552  * @param int $acc The number of digits after the decimal point, default 2
2553  * @param bool $round Whether or not to round the value, default true
2554  * @return string
2555  */
2556 function wfPercent( $nr, $acc = 2, $round = true ) {
2557         $ret = sprintf( "%.${acc}f", $nr );
2558         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2559 }
2560
2561 /**
2562  * Safety wrapper around ini_get() for boolean settings.
2563  * The values returned from ini_get() are pre-normalized for settings
2564  * set via php.ini or php_flag/php_admin_flag... but *not*
2565  * for those set via php_value/php_admin_value.
2566  *
2567  * It's fairly common for people to use php_value instead of php_flag,
2568  * which can leave you with an 'off' setting giving a false positive
2569  * for code that just takes the ini_get() return value as a boolean.
2570  *
2571  * To make things extra interesting, setting via php_value accepts
2572  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2573  * Unrecognized values go false... again opposite PHP's own coercion
2574  * from string to bool.
2575  *
2576  * Luckily, 'properly' set settings will always come back as '0' or '1',
2577  * so we only have to worry about them and the 'improper' settings.
2578  *
2579  * I frickin' hate PHP... :P
2580  *
2581  * @param string $setting
2582  * @return bool
2583  */
2584 function wfIniGetBool( $setting ) {
2585         $val = strtolower( ini_get( $setting ) );
2586         // 'on' and 'true' can't have whitespace around them, but '1' can.
2587         return $val == 'on'
2588                 || $val == 'true'
2589                 || $val == 'yes'
2590                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2591 }
2592
2593 /**
2594  * Windows-compatible version of escapeshellarg()
2595  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2596  * function puts single quotes in regardless of OS.
2597  *
2598  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2599  * earlier distro releases of PHP)
2600  *
2601  * @param string ... strings to escape and glue together, or a single array of strings parameter
2602  * @return string
2603  */
2604 function wfEscapeShellArg( /*...*/ ) {
2605         wfInitShellLocale();
2606
2607         $args = func_get_args();
2608         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2609                 // If only one argument has been passed, and that argument is an array,
2610                 // treat it as a list of arguments
2611                 $args = reset( $args );
2612         }
2613
2614         $first = true;
2615         $retVal = '';
2616         foreach ( $args as $arg ) {
2617                 if ( !$first ) {
2618                         $retVal .= ' ';
2619                 } else {
2620                         $first = false;
2621                 }
2622
2623                 if ( wfIsWindows() ) {
2624                         // Escaping for an MSVC-style command line parser and CMD.EXE
2625                         // @codingStandardsIgnoreStart For long URLs
2626                         // Refs:
2627                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2628                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2629                         //  * Bug #13518
2630                         //  * CR r63214
2631                         // Double the backslashes before any double quotes. Escape the double quotes.
2632                         // @codingStandardsIgnoreEnd
2633                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2634                         $arg = '';
2635                         $iteration = 0;
2636                         foreach ( $tokens as $token ) {
2637                                 if ( $iteration % 2 == 1 ) {
2638                                         // Delimiter, a double quote preceded by zero or more slashes
2639                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2640                                 } elseif ( $iteration % 4 == 2 ) {
2641                                         // ^ in $token will be outside quotes, need to be escaped
2642                                         $arg .= str_replace( '^', '^^', $token );
2643                                 } else { // $iteration % 4 == 0
2644                                         // ^ in $token will appear inside double quotes, so leave as is
2645                                         $arg .= $token;
2646                                 }
2647                                 $iteration++;
2648                         }
2649                         // Double the backslashes before the end of the string, because
2650                         // we will soon add a quote
2651                         $m = array();
2652                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2653                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2654                         }
2655
2656                         // Add surrounding quotes
2657                         $retVal .= '"' . $arg . '"';
2658                 } else {
2659                         $retVal .= escapeshellarg( $arg );
2660                 }
2661         }
2662         return $retVal;
2663 }
2664
2665 /**
2666  * Check if wfShellExec() is effectively disabled via php.ini config
2667  *
2668  * @return bool|string False or one of (safemode,disabled)
2669  * @since 1.22
2670  */
2671 function wfShellExecDisabled() {
2672         static $disabled = null;
2673         if ( is_null( $disabled ) ) {
2674                 if ( wfIniGetBool( 'safe_mode' ) ) {
2675                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2676                         $disabled = 'safemode';
2677                 } elseif ( !function_exists( 'proc_open' ) ) {
2678                         wfDebug( "proc_open() is disabled\n" );
2679                         $disabled = 'disabled';
2680                 } else {
2681                         $disabled = false;
2682                 }
2683         }
2684         return $disabled;
2685 }
2686
2687 /**
2688  * Execute a shell command, with time and memory limits mirrored from the PHP
2689  * configuration if supported.
2690  *
2691  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2692  *   or an array of unescaped arguments, in which case each value will be escaped
2693  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2694  * @param null|mixed &$retval Optional, will receive the program's exit code.
2695  *   (non-zero is usually failure). If there is an error from
2696  *   read, select, or proc_open(), this will be set to -1.
2697  * @param array $environ Optional environment variables which should be
2698  *   added to the executed command environment.
2699  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2700  *   this overwrites the global wgMaxShell* limits.
2701  * @param array $options Array of options:
2702  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2703  *     including errors from limit.sh
2704  *   - profileMethod: By default this function will profile based on the calling
2705  *     method. Set this to a string for an alternative method to profile from
2706  *
2707  * @return string Collected stdout as a string
2708  */
2709 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2710         $limits = array(), $options = array()
2711 ) {
2712         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2713                 $wgMaxShellWallClockTime, $wgShellCgroup;
2714
2715         $disabled = wfShellExecDisabled();
2716         if ( $disabled ) {
2717                 $retval = 1;
2718                 return $disabled == 'safemode' ?
2719                         'Unable to run external programs in safe mode.' :
2720                         'Unable to run external programs, proc_open() is disabled.';
2721         }
2722
2723         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2724         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2725
2726         wfInitShellLocale();
2727
2728         $envcmd = '';
2729         foreach ( $environ as $k => $v ) {
2730                 if ( wfIsWindows() ) {
2731                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2732                          * appear in the environment variable, so we must use carat escaping as documented in
2733                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2734                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2735                          * are listed there but doesn't appear to need it.
2736                          */
2737                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2738                 } else {
2739                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2740                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2741                          */
2742                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2743                 }
2744         }
2745         if ( is_array( $cmd ) ) {
2746                 $cmd = wfEscapeShellArg( $cmd );
2747         }
2748
2749         $cmd = $envcmd . $cmd;
2750
2751         $useLogPipe = false;
2752         if ( is_executable( '/bin/bash' ) ) {
2753                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2754                 if ( isset( $limits['walltime'] ) ) {
2755                         $wallTime = intval( $limits['walltime'] );
2756                 } elseif ( isset( $limits['time'] ) ) {
2757                         $wallTime = $time;
2758                 } else {
2759                         $wallTime = intval( $wgMaxShellWallClockTime );
2760                 }
2761                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2762                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2763
2764                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2765                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2766                                 escapeshellarg( $cmd ) . ' ' .
2767                                 escapeshellarg(
2768                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2769                                         "MW_CPU_LIMIT=$time; " .
2770                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2771                                         "MW_MEM_LIMIT=$mem; " .
2772                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2773                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2774                                         "MW_USE_LOG_PIPE=yes"
2775                                 );
2776                         $useLogPipe = true;
2777                 } elseif ( $includeStderr ) {
2778                         $cmd .= ' 2>&1';
2779                 }
2780         } elseif ( $includeStderr ) {
2781                 $cmd .= ' 2>&1';
2782         }
2783         wfDebug( "wfShellExec: $cmd\n" );
2784
2785         $desc = array(
2786                 0 => array( 'file', 'php://stdin', 'r' ),
2787                 1 => array( 'pipe', 'w' ),
2788                 2 => array( 'file', 'php://stderr', 'w' ) );
2789         if ( $useLogPipe ) {
2790                 $desc[3] = array( 'pipe', 'w' );
2791         }
2792         $pipes = null;
2793         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2794         $proc = proc_open( $cmd, $desc, $pipes );
2795         if ( !$proc ) {
2796                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2797                 $retval = -1;
2798                 return '';
2799         }
2800         $outBuffer = $logBuffer = '';
2801         $emptyArray = array();
2802         $status = false;
2803         $logMsg = false;
2804
2805         /* According to the documentation, it is possible for stream_select()
2806          * to fail due to EINTR. I haven't managed to induce this in testing
2807          * despite sending various signals. If it did happen, the error
2808          * message would take the form:
2809          *
2810          * stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2811          *
2812          * where [4] is the value of the macro EINTR and "Interrupted system
2813          * call" is string which according to the Linux manual is "possibly"
2814          * localised according to LC_MESSAGES.
2815          */
2816         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2817         $eintrMessage = "stream_select(): unable to select [$eintr]";
2818
2819         // Build a table mapping resource IDs to pipe FDs to work around a
2820         // PHP 5.3 issue in which stream_select() does not preserve array keys
2821         // <https://bugs.php.net/bug.php?id=53427>.
2822         $fds = array();
2823         foreach ( $pipes as $fd => $pipe ) {
2824                 $fds[(int)$pipe] = $fd;
2825         }
2826
2827         $running = true;
2828         $timeout = null;
2829         $numReadyPipes = 0;
2830
2831         while ( $running === true || $numReadyPipes !== 0 ) {
2832                 if ( $running ) {
2833                         $status = proc_get_status( $proc );
2834                         // If the process has terminated, switch to nonblocking selects
2835                         // for getting any data still waiting to be read.
2836                         if ( !$status['running'] ) {
2837                                 $running = false;
2838                                 $timeout = 0;
2839                         }
2840                 }
2841
2842                 $readyPipes = $pipes;
2843
2844                 // Clear last error
2845                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2846                 @trigger_error( '' );
2847                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2848                 if ( $numReadyPipes === false ) {
2849                         // @codingStandardsIgnoreEnd
2850                         $error = error_get_last();
2851                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2852                                 continue;
2853                         } else {
2854                                 trigger_error( $error['message'], E_USER_WARNING );
2855                                 $logMsg = $error['message'];
2856                                 break;
2857                         }
2858                 }
2859                 foreach ( $readyPipes as $pipe ) {
2860                         $block = fread( $pipe, 65536 );
2861                         $fd = $fds[(int)$pipe];
2862                         if ( $block === '' ) {
2863                                 // End of file
2864                                 fclose( $pipes[$fd] );
2865                                 unset( $pipes[$fd] );
2866                                 if ( !$pipes ) {
2867                                         break 2;
2868                                 }
2869                         } elseif ( $block === false ) {
2870                                 // Read error
2871                                 $logMsg = "Error reading from pipe";
2872                                 break 2;
2873                         } elseif ( $fd == 1 ) {
2874                                 // From stdout
2875                                 $outBuffer .= $block;
2876                         } elseif ( $fd == 3 ) {
2877                                 // From log FD
2878                                 $logBuffer .= $block;
2879                                 if ( strpos( $block, "\n" ) !== false ) {
2880                                         $lines = explode( "\n", $logBuffer );
2881                                         $logBuffer = array_pop( $lines );
2882                                         foreach ( $lines as $line ) {
2883                                                 wfDebugLog( 'exec', $line );
2884                                         }
2885                                 }
2886                         }
2887                 }
2888         }
2889
2890         foreach ( $pipes as $pipe ) {
2891                 fclose( $pipe );
2892         }
2893
2894         // Use the status previously collected if possible, since proc_get_status()
2895         // just calls waitpid() which will not return anything useful the second time.
2896         if ( $running ) {
2897                 $status = proc_get_status( $proc );
2898         }
2899
2900         if ( $logMsg !== false ) {
2901                 // Read/select error
2902                 $retval = -1;
2903                 proc_close( $proc );
2904         } elseif ( $status['signaled'] ) {
2905                 $logMsg = "Exited with signal {$status['termsig']}";
2906                 $retval = 128 + $status['termsig'];
2907                 proc_close( $proc );
2908         } else {
2909                 if ( $status['running'] ) {
2910                         $retval = proc_close( $proc );
2911                 } else {
2912                         $retval = $status['exitcode'];
2913                         proc_close( $proc );
2914                 }
2915                 if ( $retval == 127 ) {
2916                         $logMsg = "Possibly missing executable file";
2917                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2918                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2919                 }
2920         }
2921
2922         if ( $logMsg !== false ) {
2923                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2924         }
2925
2926         return $outBuffer;
2927 }
2928
2929 /**
2930  * Execute a shell command, returning both stdout and stderr. Convenience
2931  * function, as all the arguments to wfShellExec can become unwieldy.
2932  *
2933  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2934  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2935  *   or an array of unescaped arguments, in which case each value will be escaped
2936  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2937  * @param null|mixed &$retval Optional, will receive the program's exit code.
2938  *   (non-zero is usually failure)
2939  * @param array $environ Optional environment variables which should be
2940  *   added to the executed command environment.
2941  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2942  *   this overwrites the global wgMaxShell* limits.
2943  * @return string Collected stdout and stderr as a string
2944  */
2945 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2946         return wfShellExec( $cmd, $retval, $environ, $limits,
2947                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2948 }
2949
2950 /**
2951  * Workaround for http://bugs.php.net/bug.php?id=45132
2952  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2953  */
2954 function wfInitShellLocale() {
2955         static $done = false;
2956         if ( $done ) {
2957                 return;
2958         }
2959         $done = true;
2960         global $wgShellLocale;
2961         if ( !wfIniGetBool( 'safe_mode' ) ) {
2962                 putenv( "LC_CTYPE=$wgShellLocale" );
2963                 setlocale( LC_CTYPE, $wgShellLocale );
2964         }
2965 }
2966
2967 /**
2968  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2969  * Note that $parameters should be a flat array and an option with an argument
2970  * should consist of two consecutive items in the array (do not use "--option value").
2971  *
2972  * @param string $script MediaWiki cli script path
2973  * @param array $parameters Arguments and options to the script
2974  * @param array $options Associative array of options:
2975  *              'php': The path to the php executable
2976  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2977  * @return string
2978  */
2979 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2980         global $wgPhpCli;
2981         // Give site config file a chance to run the script in a wrapper.
2982         // The caller may likely want to call wfBasename() on $script.
2983         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2984         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2985         if ( isset( $options['wrapper'] ) ) {
2986                 $cmd[] = $options['wrapper'];
2987         }
2988         $cmd[] = $script;
2989         // Escape each parameter for shell
2990         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
2991 }
2992
2993 /**
2994  * wfMerge attempts to merge differences between three texts.
2995  * Returns true for a clean merge and false for failure or a conflict.
2996  *
2997  * @param string $old
2998  * @param string $mine
2999  * @param string $yours
3000  * @param string $result
3001  * @return bool
3002  */
3003 function wfMerge( $old, $mine, $yours, &$result ) {
3004         global $wgDiff3;
3005
3006         # This check may also protect against code injection in
3007         # case of broken installations.
3008         MediaWiki\suppressWarnings();
3009         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3010         MediaWiki\restoreWarnings();
3011
3012         if ( !$haveDiff3 ) {
3013                 wfDebug( "diff3 not found\n" );
3014                 return false;
3015         }
3016
3017         # Make temporary files
3018         $td = wfTempDir();
3019         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3020         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3021         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3022
3023         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3024         #       a newline character. To avoid this, we normalize the trailing whitespace before
3025         #       creating the diff.
3026
3027         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3028         fclose( $oldtextFile );
3029         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3030         fclose( $mytextFile );
3031         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3032         fclose( $yourtextFile );
3033
3034         # Check for a conflict
3035         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
3036                 $oldtextName, $yourtextName );
3037         $handle = popen( $cmd, 'r' );
3038
3039         if ( fgets( $handle, 1024 ) ) {
3040                 $conflict = true;
3041         } else {
3042                 $conflict = false;
3043         }
3044         pclose( $handle );
3045
3046         # Merge differences
3047         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
3048                 $oldtextName, $yourtextName );
3049         $handle = popen( $cmd, 'r' );
3050         $result = '';
3051         do {
3052                 $data = fread( $handle, 8192 );
3053                 if ( strlen( $data ) == 0 ) {
3054                         break;
3055                 }
3056                 $result .= $data;
3057         } while ( true );
3058         pclose( $handle );
3059         unlink( $mytextName );
3060         unlink( $oldtextName );
3061         unlink( $yourtextName );
3062
3063         if ( $result === '' && $old !== '' && !$conflict ) {
3064                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3065                 $conflict = true;
3066         }
3067         return !$conflict;
3068 }
3069
3070 /**
3071  * Returns unified plain-text diff of two texts.
3072  * "Useful" for machine processing of diffs.
3073  *
3074  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3075  *
3076  * @param string $before The text before the changes.
3077  * @param string $after The text after the changes.
3078  * @param string $params Command-line options for the diff command.
3079  * @return string Unified diff of $before and $after
3080  */
3081 function wfDiff( $before, $after, $params = '-u' ) {
3082         if ( $before == $after ) {
3083                 return '';
3084         }
3085
3086         global $wgDiff;
3087         MediaWiki\suppressWarnings();
3088         $haveDiff = $wgDiff && file_exists( $wgDiff );
3089         MediaWiki\restoreWarnings();
3090
3091         # This check may also protect against code injection in
3092         # case of broken installations.
3093         if ( !$haveDiff ) {
3094                 wfDebug( "diff executable not found\n" );
3095                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3096                 $format = new UnifiedDiffFormatter();
3097                 return $format->format( $diffs );
3098         }
3099
3100         # Make temporary files
3101         $td = wfTempDir();
3102         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3103         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3104
3105         fwrite( $oldtextFile, $before );
3106         fclose( $oldtextFile );
3107         fwrite( $newtextFile, $after );
3108         fclose( $newtextFile );
3109
3110         // Get the diff of the two files
3111         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3112
3113         $h = popen( $cmd, 'r' );
3114         if ( !$h ) {
3115                 unlink( $oldtextName );
3116                 unlink( $newtextName );
3117                 throw new Exception( __METHOD__ . '(): popen() failed' );
3118         }
3119
3120         $diff = '';
3121
3122         do {
3123                 $data = fread( $h, 8192 );
3124                 if ( strlen( $data ) == 0 ) {
3125                         break;
3126                 }
3127                 $diff .= $data;
3128         } while ( true );
3129
3130         // Clean up
3131         pclose( $h );
3132         unlink( $oldtextName );
3133         unlink( $newtextName );
3134
3135         // Kill the --- and +++ lines. They're not useful.
3136         $diff_lines = explode( "\n", $diff );
3137         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3138                 unset( $diff_lines[0] );
3139         }
3140         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3141                 unset( $diff_lines[1] );
3142         }
3143
3144         $diff = implode( "\n", $diff_lines );
3145
3146         return $diff;
3147 }
3148
3149 /**
3150  * This function works like "use VERSION" in Perl, the program will die with a
3151  * backtrace if the current version of PHP is less than the version provided
3152  *
3153  * This is useful for extensions which due to their nature are not kept in sync
3154  * with releases, and might depend on other versions of PHP than the main code
3155  *
3156  * Note: PHP might die due to parsing errors in some cases before it ever
3157  *       manages to call this function, such is life
3158  *
3159  * @see perldoc -f use
3160  *
3161  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3162  * @throws MWException
3163  */
3164 function wfUsePHP( $req_ver ) {
3165         $php_ver = PHP_VERSION;
3166
3167         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3168                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3169         }
3170 }
3171
3172 /**
3173  * This function works like "use VERSION" in Perl except it checks the version
3174  * of MediaWiki, the program will die with a backtrace if the current version
3175  * of MediaWiki is less than the version provided.
3176  *
3177  * This is useful for extensions which due to their nature are not kept in sync
3178  * with releases
3179  *
3180  * Note: Due to the behavior of PHP's version_compare() which is used in this
3181  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3182  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3183  * targeted version number. For example if you wanted to allow any variation
3184  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3185  * not result in the same comparison due to the internal logic of
3186  * version_compare().
3187  *
3188  * @see perldoc -f use
3189  *
3190  * @deprecated since 1.26, use the "requires' property of extension.json
3191  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3192  * @throws MWException
3193  */
3194 function wfUseMW( $req_ver ) {
3195         global $wgVersion;
3196
3197         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3198                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3199         }
3200 }
3201
3202 /**
3203  * Return the final portion of a pathname.
3204  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3205  * http://bugs.php.net/bug.php?id=33898
3206  *
3207  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3208  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3209  *
3210  * @param string $path
3211  * @param string $suffix String to remove if present
3212  * @return string
3213  */
3214 function wfBaseName( $path, $suffix = '' ) {
3215         if ( $suffix == '' ) {
3216                 $encSuffix = '';
3217         } else {
3218                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3219         }
3220
3221         $matches = array();
3222         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3223                 return $matches[1];
3224         } else {
3225                 return '';
3226         }
3227 }
3228
3229 /**
3230  * Generate a relative path name to the given file.
3231  * May explode on non-matching case-insensitive paths,
3232  * funky symlinks, etc.
3233  *
3234  * @param string $path Absolute destination path including target filename
3235  * @param string $from Absolute source path, directory only
3236  * @return string
3237  */
3238 function wfRelativePath( $path, $from ) {
3239         // Normalize mixed input on Windows...
3240         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3241         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3242
3243         // Trim trailing slashes -- fix for drive root
3244         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3245         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3246
3247         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3248         $against = explode( DIRECTORY_SEPARATOR, $from );
3249
3250         if ( $pieces[0] !== $against[0] ) {
3251                 // Non-matching Windows drive letters?
3252                 // Return a full path.
3253                 return $path;
3254         }
3255
3256         // Trim off common prefix
3257         while ( count( $pieces ) && count( $against )
3258                 && $pieces[0] == $against[0] ) {
3259                 array_shift( $pieces );
3260                 array_shift( $against );
3261         }
3262
3263         // relative dots to bump us to the parent
3264         while ( count( $against ) ) {
3265                 array_unshift( $pieces, '..' );
3266                 array_shift( $against );
3267         }
3268
3269         array_push( $pieces, wfBaseName( $path ) );
3270
3271         return implode( DIRECTORY_SEPARATOR, $pieces );
3272 }
3273
3274 /**
3275  * Convert an arbitrarily-long digit string from one numeric base
3276  * to another, optionally zero-padding to a minimum column width.
3277  *
3278  * Supports base 2 through 36; digit values 10-36 are represented
3279  * as lowercase letters a-z. Input is case-insensitive.
3280  *
3281  * @deprecated 1.27 Use Wikimedia\base_convert() directly
3282  *
3283  * @param string $input Input number
3284  * @param int $sourceBase Base of the input number
3285  * @param int $destBase Desired base of the output
3286  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3287  * @param bool $lowercase Whether to output in lowercase or uppercase
3288  * @param string $engine Either "gmp", "bcmath", or "php"
3289  * @return string|bool The output number as a string, or false on error
3290  */
3291 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3292         $lowercase = true, $engine = 'auto'
3293 ) {
3294         return Wikimedia\base_convert( $input, $sourceBase, $destBase, $pad, $lowercase, $engine );
3295 }
3296
3297 /**
3298  * Check if there is sufficient entropy in php's built-in session generation
3299  *
3300  * @return bool True = there is sufficient entropy
3301  */
3302 function wfCheckEntropy() {
3303         return (
3304                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3305                         || ini_get( 'session.entropy_file' )
3306                 )
3307                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3308 }
3309
3310 /**
3311  * Override session_id before session startup if php's built-in
3312  * session generation code is not secure.
3313  */
3314 function wfFixSessionID() {
3315         // If the cookie or session id is already set we already have a session and should abort
3316         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3317                 return;
3318         }
3319
3320         // PHP's built-in session entropy is enabled if:
3321         // - entropy_file is set or you're on Windows with php 5.3.3+
3322         // - AND entropy_length is > 0
3323         // We treat it as disabled if it doesn't have an entropy length of at least 32
3324         $entropyEnabled = wfCheckEntropy();
3325
3326         // If built-in entropy is not enabled or not sufficient override PHP's
3327         // built in session id generation code
3328         if ( !$entropyEnabled ) {
3329                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3330                         "overriding session id generation using our cryptrand source.\n" );
3331                 session_id( MWCryptRand::generateHex( 32 ) );
3332         }
3333 }
3334
3335 /**
3336  * Reset the session_id
3337  *
3338  * @since 1.22
3339  */
3340 function wfResetSessionID() {
3341         global $wgCookieSecure;
3342         $oldSessionId = session_id();
3343         $cookieParams = session_get_cookie_params();
3344         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3345                 session_regenerate_id( false );
3346         } else {
3347                 $tmp = $_SESSION;
3348                 session_destroy();
3349                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3350                 $_SESSION = $tmp;
3351         }
3352         $newSessionId = session_id();
3353 }
3354
3355 /**
3356  * Initialise php session
3357  *
3358  * @param bool $sessionId
3359  */
3360 function wfSetupSession( $sessionId = false ) {
3361         global $wgSessionsInObjectCache, $wgSessionHandler;
3362         global $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly;
3363
3364         if ( $wgSessionsInObjectCache ) {
3365                 ObjectCacheSessionHandler::install();
3366         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3367                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3368                 # hasn't already been set to the desired value (that causes errors)
3369                 ini_set( 'session.save_handler', $wgSessionHandler );
3370         }
3371
3372         session_set_cookie_params(
3373                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3374         session_cache_limiter( 'private, must-revalidate' );
3375         if ( $sessionId ) {
3376                 session_id( $sessionId );
3377         } else {
3378                 wfFixSessionID();
3379         }
3380
3381         MediaWiki\suppressWarnings();
3382         session_start();
3383         MediaWiki\restoreWarnings();
3384
3385         if ( $wgSessionsInObjectCache ) {
3386                 ObjectCacheSessionHandler::renewCurrentSession();
3387         }
3388 }
3389
3390 /**
3391  * Get an object from the precompiled serialized directory
3392  *
3393  * @param string $name
3394  * @return mixed The variable on success, false on failure
3395  */
3396 function wfGetPrecompiledData( $name ) {
3397         global $IP;
3398
3399         $file = "$IP/serialized/$name";
3400         if ( file_exists( $file ) ) {
3401                 $blob = file_get_contents( $file );
3402                 if ( $blob ) {
3403                         return unserialize( $blob );
3404                 }
3405         }
3406         return false;
3407 }
3408
3409 /**
3410  * Make a cache key for the local wiki.
3411  *
3412  * @param string $args,...
3413  * @return string
3414  */
3415 function wfMemcKey( /*...*/ ) {
3416         return call_user_func_array(
3417                 array( ObjectCache::getLocalClusterInstance(), 'makeKey' ),
3418                 func_get_args()
3419         );
3420 }
3421
3422 /**
3423  * Make a cache key for a foreign DB.
3424  *
3425  * Must match what wfMemcKey() would produce in context of the foreign wiki.
3426  *
3427  * @param string $db
3428  * @param string $prefix
3429  * @param string $args,...
3430  * @return string
3431  */
3432 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3433         $args = array_slice( func_get_args(), 2 );
3434         $keyspace = $prefix ? "$db-$prefix" : $db;
3435         return call_user_func_array(
3436                 array( ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ),
3437                 array( $keyspace, $args )
3438         );
3439 }
3440
3441 /**
3442  * Make a cache key with database-agnostic prefix.
3443  *
3444  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3445  * instead. Must have a prefix as otherwise keys that use a database name
3446  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3447  *
3448  * @since 1.26
3449  * @param string $args,...
3450  * @return string
3451  */
3452 function wfGlobalCacheKey( /*...*/ ) {
3453         return call_user_func_array(
3454                 array( ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ),
3455                 func_get_args()
3456         );
3457 }
3458
3459 /**
3460  * Get an ASCII string identifying this wiki
3461  * This is used as a prefix in memcached keys
3462  *
3463  * @return string
3464  */
3465 function wfWikiID() {
3466         global $wgDBprefix, $wgDBname;
3467         if ( $wgDBprefix ) {
3468                 return "$wgDBname-$wgDBprefix";
3469         } else {
3470                 return $wgDBname;
3471         }
3472 }
3473
3474 /**
3475  * Split a wiki ID into DB name and table prefix
3476  *
3477  * @param string $wiki
3478  *
3479  * @return array
3480  */
3481 function wfSplitWikiID( $wiki ) {
3482         $bits = explode( '-', $wiki, 2 );
3483         if ( count( $bits ) < 2 ) {
3484                 $bits[] = '';
3485         }
3486         return $bits;
3487 }
3488
3489 /**
3490  * Get a Database object.
3491  *
3492  * @param int $db Index of the connection to get. May be DB_MASTER for the
3493  *            master (for write queries), DB_SLAVE for potentially lagged read
3494  *            queries, or an integer >= 0 for a particular server.
3495  *
3496  * @param string|string[] $groups Query groups. An array of group names that this query
3497  *                belongs to. May contain a single string if the query is only
3498  *                in one group.
3499  *
3500  * @param string|bool $wiki The wiki ID, or false for the current wiki
3501  *
3502  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3503  * will always return the same object, unless the underlying connection or load
3504  * balancer is manually destroyed.
3505  *
3506  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3507  * updater to ensure that a proper database is being updated.
3508  *
3509  * @return DatabaseBase
3510  */
3511 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3512         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3513 }
3514
3515 /**
3516  * Get a load balancer object.
3517  *
3518  * @param string|bool $wiki Wiki ID, or false for the current wiki
3519  * @return LoadBalancer
3520  */
3521 function wfGetLB( $wiki = false ) {
3522         return wfGetLBFactory()->getMainLB( $wiki );
3523 }
3524
3525 /**
3526  * Get the load balancer factory object
3527  *
3528  * @return LBFactory
3529  */
3530 function wfGetLBFactory() {
3531         return LBFactory::singleton();
3532 }
3533
3534 /**
3535  * Find a file.
3536  * Shortcut for RepoGroup::singleton()->findFile()
3537  *
3538  * @param string $title String or Title object
3539  * @param array $options Associative array of options (see RepoGroup::findFile)
3540  * @return File|bool File, or false if the file does not exist
3541  */
3542 function wfFindFile( $title, $options = array() ) {
3543         return RepoGroup::singleton()->findFile( $title, $options );
3544 }
3545
3546 /**
3547  * Get an object referring to a locally registered file.
3548  * Returns a valid placeholder object if the file does not exist.
3549  *
3550  * @param Title|string $title
3551  * @return LocalFile|null A File, or null if passed an invalid Title
3552  */
3553 function wfLocalFile( $title ) {
3554         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3555 }
3556
3557 /**
3558  * Should low-performance queries be disabled?
3559  *
3560  * @return bool
3561  * @codeCoverageIgnore
3562  */
3563 function wfQueriesMustScale() {
3564         global $wgMiserMode;
3565         return $wgMiserMode
3566                 || ( SiteStats::pages() > 100000
3567                 && SiteStats::edits() > 1000000
3568                 && SiteStats::users() > 10000 );
3569 }
3570
3571 /**
3572  * Get the path to a specified script file, respecting file
3573  * extensions; this is a wrapper around $wgScriptPath etc.
3574  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3575  *
3576  * @param string $script Script filename, sans extension
3577  * @return string
3578  */
3579 function wfScript( $script = 'index' ) {
3580         global $wgScriptPath, $wgScript, $wgLoadScript;
3581         if ( $script === 'index' ) {
3582                 return $wgScript;
3583         } elseif ( $script === 'load' ) {
3584                 return $wgLoadScript;
3585         } else {
3586                 return "{$wgScriptPath}/{$script}.php";
3587         }
3588 }
3589
3590 /**
3591  * Get the script URL.
3592  *
3593  * @return string Script URL
3594  */
3595 function wfGetScriptUrl() {
3596         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3597                 /* as it was called, minus the query string.
3598                  *
3599                  * Some sites use Apache rewrite rules to handle subdomains,
3600                  * and have PHP set up in a weird way that causes PHP_SELF
3601                  * to contain the rewritten URL instead of the one that the
3602                  * outside world sees.
3603                  *
3604                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
3605                  * provides containing the "before" URL.
3606                  */
3607                 return $_SERVER['SCRIPT_NAME'];
3608         } else {
3609                 return $_SERVER['URL'];
3610         }
3611 }
3612
3613 /**
3614  * Convenience function converts boolean values into "true"
3615  * or "false" (string) values
3616  *
3617  * @param bool $value
3618  * @return string
3619  */
3620 function wfBoolToStr( $value ) {
3621         return $value ? 'true' : 'false';
3622 }
3623
3624 /**
3625  * Get a platform-independent path to the null file, e.g. /dev/null
3626  *
3627  * @return string
3628  */
3629 function wfGetNull() {
3630         return wfIsWindows() ? 'NUL' : '/dev/null';
3631 }
3632
3633 /**
3634  * Waits for the slaves to catch up to the master position
3635  *
3636  * Use this when updating very large numbers of rows, as in maintenance scripts,
3637  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3638  *
3639  * By default this waits on the main DB cluster of the current wiki.
3640  * If $cluster is set to "*" it will wait on all DB clusters, including
3641  * external ones. If the lag being waiting on is caused by the code that
3642  * does this check, it makes since to use $ifWritesSince, particularly if
3643  * cluster is "*", to avoid excess overhead.
3644  *
3645  * Never call this function after a big DB write that is still in a transaction.
3646  * This only makes sense after the possible lag inducing changes were committed.
3647  *
3648  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3649  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3650  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3651  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3652  * @return bool Success (able to connect and no timeouts reached)
3653  */
3654 function wfWaitForSlaves(
3655         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3656 ) {
3657         // B/C: first argument used to be "max seconds of lag"; ignore such values
3658         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3659
3660         if ( $timeout === null ) {
3661                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3662         }
3663
3664         // Figure out which clusters need to be checked
3665         /** @var LoadBalancer[] $lbs */
3666         $lbs = array();
3667         if ( $cluster === '*' ) {
3668                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3669                         $lbs[] = $lb;
3670                 } );
3671         } elseif ( $cluster !== false ) {
3672                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3673         } else {
3674                 $lbs[] = wfGetLB( $wiki );
3675         }
3676
3677         // Get all the master positions of applicable DBs right now.
3678         // This can be faster since waiting on one cluster reduces the
3679         // time needed to wait on the next clusters.
3680         $masterPositions = array_fill( 0, count( $lbs ), false );
3681         foreach ( $lbs as $i => $lb ) {
3682                 if ( $lb->getServerCount() <= 1 ) {
3683                         // Bug 27975 - Don't try to wait for slaves if there are none
3684                         // Prevents permission error when getting master position
3685                         continue;
3686                 } elseif ( $ifWritesSince && $lb->lastMasterChangeTimestamp() < $ifWritesSince ) {
3687                         continue; // no writes since the last wait
3688                 }
3689                 $masterPositions[$i] = $lb->getMasterPos();
3690         }
3691
3692         $ok = true;
3693         foreach ( $lbs as $i => $lb ) {
3694                 if ( $masterPositions[$i] ) {
3695                         // The DBMS may not support getMasterPos() or the whole
3696                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3697                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3698                 }
3699         }
3700
3701         return $ok;
3702 }
3703
3704 /**
3705  * Count down from $seconds to zero on the terminal, with a one-second pause
3706  * between showing each number. For use in command-line scripts.
3707  *
3708  * @codeCoverageIgnore
3709  * @param int $seconds
3710  */
3711 function wfCountDown( $seconds ) {
3712         for ( $i = $seconds; $i >= 0; $i-- ) {
3713                 if ( $i != $seconds ) {
3714                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3715                 }
3716                 echo $i;
3717                 flush();
3718                 if ( $i ) {
3719                         sleep( 1 );
3720                 }
3721         }
3722         echo "\n";
3723 }
3724
3725 /**
3726  * Replace all invalid characters with -
3727  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3728  * By default, $wgIllegalFileChars = ':'
3729  *
3730  * @param string $name Filename to process
3731  * @return string
3732  */
3733 function wfStripIllegalFilenameChars( $name ) {
3734         global $wgIllegalFileChars;
3735         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3736         $name = wfBaseName( $name );
3737         $name = preg_replace(
3738                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3739                 '-',
3740                 $name
3741         );
3742         return $name;
3743 }
3744
3745 /**
3746  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3747  *
3748  * @return int Resulting value of the memory limit.
3749  */
3750 function wfMemoryLimit() {
3751         global $wgMemoryLimit;
3752         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3753         if ( $memlimit != -1 ) {
3754                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3755                 if ( $conflimit == -1 ) {
3756                         wfDebug( "Removing PHP's memory limit\n" );
3757                         MediaWiki\suppressWarnings();
3758                         ini_set( 'memory_limit', $conflimit );
3759                         MediaWiki\restoreWarnings();
3760                         return $conflimit;
3761                 } elseif ( $conflimit > $memlimit ) {
3762                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3763                         MediaWiki\suppressWarnings();
3764                         ini_set( 'memory_limit', $conflimit );
3765                         MediaWiki\restoreWarnings();
3766                         return $conflimit;
3767                 }
3768         }
3769         return $memlimit;
3770 }
3771
3772 /**
3773  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3774  *
3775  * @return int Prior time limit
3776  * @since 1.26
3777  */
3778 function wfTransactionalTimeLimit() {
3779         global $wgTransactionalTimeLimit;
3780
3781         $timeLimit = ini_get( 'max_execution_time' );
3782         // Note that CLI scripts use 0
3783         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3784                 set_time_limit( $wgTransactionalTimeLimit );
3785         }
3786
3787         ignore_user_abort( true ); // ignore client disconnects
3788
3789         return $timeLimit;
3790 }
3791
3792 /**
3793  * Converts shorthand byte notation to integer form
3794  *
3795  * @param string $string
3796  * @param int $default Returned if $string is empty
3797  * @return int
3798  */
3799 function wfShorthandToInteger( $string = '', $default = -1 ) {
3800         $string = trim( $string );
3801         if ( $string === '' ) {
3802                 return $default;
3803         }
3804         $last = $string[strlen( $string ) - 1];
3805         $val = intval( $string );
3806         switch ( $last ) {
3807                 case 'g':
3808                 case 'G':
3809                         $val *= 1024;
3810                         // break intentionally missing
3811                 case 'm':
3812                 case 'M':
3813                         $val *= 1024;
3814                         // break intentionally missing
3815                 case 'k':
3816                 case 'K':
3817                         $val *= 1024;
3818         }
3819
3820         return $val;
3821 }
3822
3823 /**
3824  * Get the normalised IETF language tag
3825  * See unit test for examples.
3826  *
3827  * @param string $code The language code.
3828  * @return string The language code which complying with BCP 47 standards.
3829  */
3830 function wfBCP47( $code ) {
3831         $codeSegment = explode( '-', $code );
3832         $codeBCP = array();
3833         foreach ( $codeSegment as $segNo => $seg ) {
3834                 // when previous segment is x, it is a private segment and should be lc
3835                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3836                         $codeBCP[$segNo] = strtolower( $seg );
3837                 // ISO 3166 country code
3838                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3839                         $codeBCP[$segNo] = strtoupper( $seg );
3840                 // ISO 15924 script code
3841                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3842                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3843                 // Use lowercase for other cases
3844                 } else {
3845                         $codeBCP[$segNo] = strtolower( $seg );
3846                 }
3847         }
3848         $langCode = implode( '-', $codeBCP );
3849         return $langCode;
3850 }
3851
3852 /**
3853  * Get a specific cache object.
3854  *
3855  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3856  * @return BagOStuff
3857  */
3858 function wfGetCache( $cacheType ) {
3859         return ObjectCache::getInstance( $cacheType );
3860 }
3861
3862 /**
3863  * Get the main cache object
3864  *
3865  * @return BagOStuff
3866  */
3867 function wfGetMainCache() {
3868         global $wgMainCacheType;
3869         return ObjectCache::getInstance( $wgMainCacheType );
3870 }
3871
3872 /**
3873  * Get the cache object used by the message cache
3874  *
3875  * @return BagOStuff
3876  */
3877 function wfGetMessageCacheStorage() {
3878         global $wgMessageCacheType;
3879         return ObjectCache::getInstance( $wgMessageCacheType );
3880 }
3881
3882 /**
3883  * Get the cache object used by the parser cache
3884  *
3885  * @return BagOStuff
3886  */
3887 function wfGetParserCacheStorage() {
3888         global $wgParserCacheType;
3889         return ObjectCache::getInstance( $wgParserCacheType );
3890 }
3891
3892 /**
3893  * Call hook functions defined in $wgHooks
3894  *
3895  * @param string $event Event name
3896  * @param array $args Parameters passed to hook functions
3897  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3898  *
3899  * @return bool True if no handler aborted the hook
3900  * @deprecated 1.25 - use Hooks::run
3901  */
3902 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3903         return Hooks::run( $event, $args, $deprecatedVersion );
3904 }
3905
3906 /**
3907  * Wrapper around php's unpack.
3908  *
3909  * @param string $format The format string (See php's docs)
3910  * @param string $data A binary string of binary data
3911  * @param int|bool $length The minimum length of $data or false. This is to
3912  *      prevent reading beyond the end of $data. false to disable the check.
3913  *
3914  * Also be careful when using this function to read unsigned 32 bit integer
3915  * because php might make it negative.
3916  *
3917  * @throws MWException If $data not long enough, or if unpack fails
3918  * @return array Associative array of the extracted data
3919  */
3920 function wfUnpack( $format, $data, $length = false ) {
3921         if ( $length !== false ) {
3922                 $realLen = strlen( $data );
3923                 if ( $realLen < $length ) {
3924                         throw new MWException( "Tried to use wfUnpack on a "
3925                                 . "string of length $realLen, but needed one "
3926                                 . "of at least length $length."
3927                         );
3928                 }
3929         }
3930
3931         MediaWiki\suppressWarnings();
3932         $result = unpack( $format, $data );
3933         MediaWiki\restoreWarnings();
3934
3935         if ( $result === false ) {
3936                 // If it cannot extract the packed data.
3937                 throw new MWException( "unpack could not unpack binary data" );
3938         }
3939         return $result;
3940 }
3941
3942 /**
3943  * Determine if an image exists on the 'bad image list'.
3944  *
3945  * The format of MediaWiki:Bad_image_list is as follows:
3946  *    * Only list items (lines starting with "*") are considered
3947  *    * The first link on a line must be a link to a bad image
3948  *    * Any subsequent links on the same line are considered to be exceptions,
3949  *      i.e. articles where the image may occur inline.
3950  *
3951  * @param string $name The image name to check
3952  * @param Title|bool $contextTitle The page on which the image occurs, if known
3953  * @param string $blacklist Wikitext of a file blacklist
3954  * @return bool
3955  */
3956 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3957         # Handle redirects; callers almost always hit wfFindFile() anyway,
3958         # so just use that method because it has a fast process cache.
3959         $file = wfFindFile( $name ); // get the final name
3960         $name = $file ? $file->getTitle()->getDBkey() : $name;
3961
3962         # Run the extension hook
3963         $bad = false;
3964         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
3965                 return $bad;
3966         }
3967
3968         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3969         $key = wfMemcKey( 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist ) );
3970         $badImages = $cache->get( $key );
3971
3972         if ( $badImages === false ) { // cache miss
3973                 if ( $blacklist === null ) {
3974                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3975                 }
3976                 # Build the list now
3977                 $badImages = array();
3978                 $lines = explode( "\n", $blacklist );
3979                 foreach ( $lines as $line ) {
3980                         # List items only
3981                         if ( substr( $line, 0, 1 ) !== '*' ) {
3982                                 continue;
3983                         }
3984
3985                         # Find all links
3986                         $m = array();
3987                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3988                                 continue;
3989                         }
3990
3991                         $exceptions = array();
3992                         $imageDBkey = false;
3993                         foreach ( $m[1] as $i => $titleText ) {
3994                                 $title = Title::newFromText( $titleText );
3995                                 if ( !is_null( $title ) ) {
3996                                         if ( $i == 0 ) {
3997                                                 $imageDBkey = $title->getDBkey();
3998                                         } else {
3999                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4000                                         }
4001                                 }
4002                         }
4003
4004                         if ( $imageDBkey !== false ) {
4005                                 $badImages[$imageDBkey] = $exceptions;
4006                         }
4007                 }
4008                 $cache->set( $key, $badImages, 60 );
4009         }
4010
4011         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4012         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4013
4014         return $bad;
4015 }
4016
4017 /**
4018  * Determine whether the client at a given source IP is likely to be able to
4019  * access the wiki via HTTPS.
4020  *
4021  * @param string $ip The IPv4/6 address in the normal human-readable form
4022  * @return bool
4023  */
4024 function wfCanIPUseHTTPS( $ip ) {
4025         $canDo = true;
4026         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4027         return !!$canDo;
4028 }
4029
4030 /**
4031  * Determine input string is represents as infinity
4032  *
4033  * @param string $str The string to determine
4034  * @return bool
4035  * @since 1.25
4036  */
4037 function wfIsInfinity( $str ) {
4038         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4039         return in_array( $str, $infinityValues );
4040 }
4041
4042 /**
4043  * Returns true if these thumbnail parameters match one that MediaWiki
4044  * requests from file description pages and/or parser output.
4045  *
4046  * $params is considered non-standard if they involve a non-standard
4047  * width or any non-default parameters aside from width and page number.
4048  * The number of possible files with standard parameters is far less than
4049  * that of all combinations; rate-limiting for them can thus be more generious.
4050  *
4051  * @param File $file
4052  * @param array $params
4053  * @return bool
4054  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4055  */
4056 function wfThumbIsStandard( File $file, array $params ) {
4057         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4058
4059         $multipliers = array( 1 );
4060         if ( $wgResponsiveImages ) {
4061                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4062                 // @see Linker::processResponsiveImages
4063                 $multipliers[] = 1.5;
4064                 $multipliers[] = 2;
4065         }
4066
4067         $handler = $file->getHandler();
4068         if ( !$handler || !isset( $params['width'] ) ) {
4069                 return false;
4070         }
4071
4072         $basicParams = array();
4073         if ( isset( $params['page'] ) ) {
4074                 $basicParams['page'] = $params['page'];
4075         }
4076
4077         $thumbLimits = array();
4078         $imageLimits = array();
4079         // Expand limits to account for multipliers
4080         foreach ( $multipliers as $multiplier ) {
4081                 $thumbLimits = array_merge( $thumbLimits, array_map(
4082                         function ( $width ) use ( $multiplier ) {
4083                                 return round( $width * $multiplier );
4084                         }, $wgThumbLimits )
4085                 );
4086                 $imageLimits = array_merge( $imageLimits, array_map(
4087                         function ( $pair ) use ( $multiplier ) {
4088                                 return array(
4089                                         round( $pair[0] * $multiplier ),
4090                                         round( $pair[1] * $multiplier ),
4091                                 );
4092                         }, $wgImageLimits )
4093                 );
4094         }
4095
4096         // Check if the width matches one of $wgThumbLimits
4097         if ( in_array( $params['width'], $thumbLimits ) ) {
4098                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4099                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4100                 $handler->normaliseParams( $file, $normalParams );
4101         } else {
4102                 // If not, then check if the width matchs one of $wgImageLimits
4103                 $match = false;
4104                 foreach ( $imageLimits as $pair ) {
4105                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4106                         // Decide whether the thumbnail should be scaled on width or height.
4107                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4108                         $handler->normaliseParams( $file, $normalParams );
4109                         // Check if this standard thumbnail size maps to the given width
4110                         if ( $normalParams['width'] == $params['width'] ) {
4111                                 $match = true;
4112                                 break;
4113                         }
4114                 }
4115                 if ( !$match ) {
4116                         return false; // not standard for description pages
4117                 }
4118         }
4119
4120         // Check that the given values for non-page, non-width, params are just defaults
4121         foreach ( $params as $key => $value ) {
4122                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4123                         return false;
4124                 }
4125         }
4126
4127         return true;
4128 }
4129
4130 /**
4131  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
4132  *
4133  * Values that exist in both values will be combined with += (all values of the array
4134  * of $newValues will be added to the values of the array of $baseArray, while values,
4135  * that exists in both, the value of $baseArray will be used).
4136  *
4137  * @param array $baseArray The array where you want to add the values of $newValues to
4138  * @param array $newValues An array with new values
4139  * @return array The combined array
4140  * @since 1.26
4141  */
4142 function wfArrayPlus2d( array $baseArray, array $newValues ) {
4143         // First merge items that are in both arrays
4144         foreach ( $baseArray as $name => &$groupVal ) {
4145                 if ( isset( $newValues[$name] ) ) {
4146                         $groupVal += $newValues[$name];
4147                 }
4148         }
4149         // Now add items that didn't exist yet
4150         $baseArray += $newValues;
4151
4152         return $baseArray;
4153 }