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  * Replace message parameter keys on the given formatted output.
1465  *
1466  * @param string $message
1467  * @param array $args
1468  * @return string
1469  * @private
1470  */
1471 function wfMsgReplaceArgs( $message, $args ) {
1472         # Fix windows line-endings
1473         # Some messages are split with explode("\n", $msg)
1474         $message = str_replace( "\r", '', $message );
1475
1476         // Replace arguments
1477         if ( is_array( $args ) && $args ) {
1478                 if ( is_array( $args[0] ) ) {
1479                         $args = array_values( $args[0] );
1480                 }
1481                 $replacementKeys = array();
1482                 foreach ( $args as $n => $param ) {
1483                         $replacementKeys['$' . ( $n + 1 )] = $param;
1484                 }
1485                 $message = strtr( $message, $replacementKeys );
1486         }
1487
1488         return $message;
1489 }
1490
1491 /**
1492  * Fetch server name for use in error reporting etc.
1493  * Use real server name if available, so we know which machine
1494  * in a server farm generated the current page.
1495  *
1496  * @return string
1497  */
1498 function wfHostname() {
1499         static $host;
1500         if ( is_null( $host ) ) {
1501
1502                 # Hostname overriding
1503                 global $wgOverrideHostname;
1504                 if ( $wgOverrideHostname !== false ) {
1505                         # Set static and skip any detection
1506                         $host = $wgOverrideHostname;
1507                         return $host;
1508                 }
1509
1510                 if ( function_exists( 'posix_uname' ) ) {
1511                         // This function not present on Windows
1512                         $uname = posix_uname();
1513                 } else {
1514                         $uname = false;
1515                 }
1516                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1517                         $host = $uname['nodename'];
1518                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1519                         # Windows computer name
1520                         $host = getenv( 'COMPUTERNAME' );
1521                 } else {
1522                         # This may be a virtual server.
1523                         $host = $_SERVER['SERVER_NAME'];
1524                 }
1525         }
1526         return $host;
1527 }
1528
1529 /**
1530  * Returns a script tag that stores the amount of time it took MediaWiki to
1531  * handle the request in milliseconds as 'wgBackendResponseTime'.
1532  *
1533  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1534  * hostname of the server handling the request.
1535  *
1536  * @return string
1537  */
1538 function wfReportTime() {
1539         global $wgRequestTime, $wgShowHostnames;
1540
1541         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1542         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1543         if ( $wgShowHostnames ) {
1544                 $reportVars['wgHostname'] = wfHostname();
1545         }
1546         return Skin::makeVariablesScript( $reportVars );
1547 }
1548
1549 /**
1550  * Safety wrapper for debug_backtrace().
1551  *
1552  * Will return an empty array if debug_backtrace is disabled, otherwise
1553  * the output from debug_backtrace() (trimmed).
1554  *
1555  * @param int $limit This parameter can be used to limit the number of stack frames returned
1556  *
1557  * @return array Array of backtrace information
1558  */
1559 function wfDebugBacktrace( $limit = 0 ) {
1560         static $disabled = null;
1561
1562         if ( is_null( $disabled ) ) {
1563                 $disabled = !function_exists( 'debug_backtrace' );
1564                 if ( $disabled ) {
1565                         wfDebug( "debug_backtrace() is disabled\n" );
1566                 }
1567         }
1568         if ( $disabled ) {
1569                 return array();
1570         }
1571
1572         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1573                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1574         } else {
1575                 return array_slice( debug_backtrace(), 1 );
1576         }
1577 }
1578
1579 /**
1580  * Get a debug backtrace as a string
1581  *
1582  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1583  *   Defaults to $wgCommandLineMode if unset.
1584  * @return string
1585  * @since 1.25 Supports $raw parameter.
1586  */
1587 function wfBacktrace( $raw = null ) {
1588         global $wgCommandLineMode;
1589
1590         if ( $raw === null ) {
1591                 $raw = $wgCommandLineMode;
1592         }
1593
1594         if ( $raw ) {
1595                 $frameFormat = "%s line %s calls %s()\n";
1596                 $traceFormat = "%s";
1597         } else {
1598                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1599                 $traceFormat = "<ul>\n%s</ul>\n";
1600         }
1601
1602         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1603                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1604                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1605                 $call = $frame['function'];
1606                 if ( !empty( $frame['class'] ) ) {
1607                         $call = $frame['class'] . $frame['type'] . $call;
1608                 }
1609                 return sprintf( $frameFormat, $file, $line, $call );
1610         }, wfDebugBacktrace() );
1611
1612         return sprintf( $traceFormat, implode( '', $frames ) );
1613 }
1614
1615 /**
1616  * Get the name of the function which called this function
1617  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1618  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1619  * wfGetCaller( 3 ) is the parent of that.
1620  *
1621  * @param int $level
1622  * @return string
1623  */
1624 function wfGetCaller( $level = 2 ) {
1625         $backtrace = wfDebugBacktrace( $level + 1 );
1626         if ( isset( $backtrace[$level] ) ) {
1627                 return wfFormatStackFrame( $backtrace[$level] );
1628         } else {
1629                 return 'unknown';
1630         }
1631 }
1632
1633 /**
1634  * Return a string consisting of callers in the stack. Useful sometimes
1635  * for profiling specific points.
1636  *
1637  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1638  * @return string
1639  */
1640 function wfGetAllCallers( $limit = 3 ) {
1641         $trace = array_reverse( wfDebugBacktrace() );
1642         if ( !$limit || $limit > count( $trace ) - 1 ) {
1643                 $limit = count( $trace ) - 1;
1644         }
1645         $trace = array_slice( $trace, -$limit - 1, $limit );
1646         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1647 }
1648
1649 /**
1650  * Return a string representation of frame
1651  *
1652  * @param array $frame
1653  * @return string
1654  */
1655 function wfFormatStackFrame( $frame ) {
1656         if ( !isset( $frame['function'] ) ) {
1657                 return 'NO_FUNCTION_GIVEN';
1658         }
1659         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1660                 $frame['class'] . $frame['type'] . $frame['function'] :
1661                 $frame['function'];
1662 }
1663
1664 /* Some generic result counters, pulled out of SearchEngine */
1665
1666 /**
1667  * @todo document
1668  *
1669  * @param int $offset
1670  * @param int $limit
1671  * @return string
1672  */
1673 function wfShowingResults( $offset, $limit ) {
1674         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1675 }
1676
1677 /**
1678  * @todo document
1679  * @todo FIXME: We may want to blacklist some broken browsers
1680  *
1681  * @param bool $force
1682  * @return bool Whereas client accept gzip compression
1683  */
1684 function wfClientAcceptsGzip( $force = false ) {
1685         static $result = null;
1686         if ( $result === null || $force ) {
1687                 $result = false;
1688                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1689                         # @todo FIXME: We may want to blacklist some broken browsers
1690                         $m = array();
1691                         if ( preg_match(
1692                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1693                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1694                                         $m
1695                                 )
1696                         ) {
1697                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1698                                         $result = false;
1699                                         return $result;
1700                                 }
1701                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1702                                 $result = true;
1703                         }
1704                 }
1705         }
1706         return $result;
1707 }
1708
1709 /**
1710  * Escapes the given text so that it may be output using addWikiText()
1711  * without any linking, formatting, etc. making its way through. This
1712  * is achieved by substituting certain characters with HTML entities.
1713  * As required by the callers, "<nowiki>" is not used.
1714  *
1715  * @param string $text Text to be escaped
1716  * @return string
1717  */
1718 function wfEscapeWikiText( $text ) {
1719         static $repl = null, $repl2 = null;
1720         if ( $repl === null ) {
1721                 $repl = array(
1722                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1723                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1724                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1725                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1726                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1727                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1728                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1729                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1730                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1731                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1732                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1733                         '__' => '_&#95;', '://' => '&#58;//',
1734                 );
1735
1736                 // We have to catch everything "\s" matches in PCRE
1737                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
1738                         $repl["$magic "] = "$magic&#32;";
1739                         $repl["$magic\t"] = "$magic&#9;";
1740                         $repl["$magic\r"] = "$magic&#13;";
1741                         $repl["$magic\n"] = "$magic&#10;";
1742                         $repl["$magic\f"] = "$magic&#12;";
1743                 }
1744
1745                 // And handle protocols that don't use "://"
1746                 global $wgUrlProtocols;
1747                 $repl2 = array();
1748                 foreach ( $wgUrlProtocols as $prot ) {
1749                         if ( substr( $prot, -1 ) === ':' ) {
1750                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1751                         }
1752                 }
1753                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
1754         }
1755         $text = substr( strtr( "\n$text", $repl ), 1 );
1756         $text = preg_replace( $repl2, '$1&#58;', $text );
1757         return $text;
1758 }
1759
1760 /**
1761  * Sets dest to source and returns the original value of dest
1762  * If source is NULL, it just returns the value, it doesn't set the variable
1763  * If force is true, it will set the value even if source is NULL
1764  *
1765  * @param mixed $dest
1766  * @param mixed $source
1767  * @param bool $force
1768  * @return mixed
1769  */
1770 function wfSetVar( &$dest, $source, $force = false ) {
1771         $temp = $dest;
1772         if ( !is_null( $source ) || $force ) {
1773                 $dest = $source;
1774         }
1775         return $temp;
1776 }
1777
1778 /**
1779  * As for wfSetVar except setting a bit
1780  *
1781  * @param int $dest
1782  * @param int $bit
1783  * @param bool $state
1784  *
1785  * @return bool
1786  */
1787 function wfSetBit( &$dest, $bit, $state = true ) {
1788         $temp = (bool)( $dest & $bit );
1789         if ( !is_null( $state ) ) {
1790                 if ( $state ) {
1791                         $dest |= $bit;
1792                 } else {
1793                         $dest &= ~$bit;
1794                 }
1795         }
1796         return $temp;
1797 }
1798
1799 /**
1800  * A wrapper around the PHP function var_export().
1801  * Either print it or add it to the regular output ($wgOut).
1802  *
1803  * @param mixed $var A PHP variable to dump.
1804  */
1805 function wfVarDump( $var ) {
1806         global $wgOut;
1807         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1808         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1809                 print $s;
1810         } else {
1811                 $wgOut->addHTML( $s );
1812         }
1813 }
1814
1815 /**
1816  * Provide a simple HTTP error.
1817  *
1818  * @param int|string $code
1819  * @param string $label
1820  * @param string $desc
1821  */
1822 function wfHttpError( $code, $label, $desc ) {
1823         global $wgOut;
1824         HttpStatus::header( $code );
1825         if ( $wgOut ) {
1826                 $wgOut->disable();
1827                 $wgOut->sendCacheControl();
1828         }
1829
1830         header( 'Content-type: text/html; charset=utf-8' );
1831         print '<!DOCTYPE html>' .
1832                 '<html><head><title>' .
1833                 htmlspecialchars( $label ) .
1834                 '</title></head><body><h1>' .
1835                 htmlspecialchars( $label ) .
1836                 '</h1><p>' .
1837                 nl2br( htmlspecialchars( $desc ) ) .
1838                 "</p></body></html>\n";
1839 }
1840
1841 /**
1842  * Clear away any user-level output buffers, discarding contents.
1843  *
1844  * Suitable for 'starting afresh', for instance when streaming
1845  * relatively large amounts of data without buffering, or wanting to
1846  * output image files without ob_gzhandler's compression.
1847  *
1848  * The optional $resetGzipEncoding parameter controls suppression of
1849  * the Content-Encoding header sent by ob_gzhandler; by default it
1850  * is left. See comments for wfClearOutputBuffers() for why it would
1851  * be used.
1852  *
1853  * Note that some PHP configuration options may add output buffer
1854  * layers which cannot be removed; these are left in place.
1855  *
1856  * @param bool $resetGzipEncoding
1857  */
1858 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1859         if ( $resetGzipEncoding ) {
1860                 // Suppress Content-Encoding and Content-Length
1861                 // headers from 1.10+s wfOutputHandler
1862                 global $wgDisableOutputCompression;
1863                 $wgDisableOutputCompression = true;
1864         }
1865         while ( $status = ob_get_status() ) {
1866                 if ( isset( $status['flags'] ) ) {
1867                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1868                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1869                 } elseif ( isset( $status['del'] ) ) {
1870                         $deleteable = $status['del'];
1871                 } else {
1872                         // Guess that any PHP-internal setting can't be removed.
1873                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1874                 }
1875                 if ( !$deleteable ) {
1876                         // Give up, and hope the result doesn't break
1877                         // output behavior.
1878                         break;
1879                 }
1880                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1881                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1882                         break;
1883                 }
1884                 if ( !ob_end_clean() ) {
1885                         // Could not remove output buffer handler; abort now
1886                         // to avoid getting in some kind of infinite loop.
1887                         break;
1888                 }
1889                 if ( $resetGzipEncoding ) {
1890                         if ( $status['name'] == 'ob_gzhandler' ) {
1891                                 // Reset the 'Content-Encoding' field set by this handler
1892                                 // so we can start fresh.
1893                                 header_remove( 'Content-Encoding' );
1894                                 break;
1895                         }
1896                 }
1897         }
1898 }
1899
1900 /**
1901  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1902  *
1903  * Clear away output buffers, but keep the Content-Encoding header
1904  * produced by ob_gzhandler, if any.
1905  *
1906  * This should be used for HTTP 304 responses, where you need to
1907  * preserve the Content-Encoding header of the real result, but
1908  * also need to suppress the output of ob_gzhandler to keep to spec
1909  * and avoid breaking Firefox in rare cases where the headers and
1910  * body are broken over two packets.
1911  */
1912 function wfClearOutputBuffers() {
1913         wfResetOutputBuffers( false );
1914 }
1915
1916 /**
1917  * Converts an Accept-* header into an array mapping string values to quality
1918  * factors
1919  *
1920  * @param string $accept
1921  * @param string $def Default
1922  * @return float[] Associative array of string => float pairs
1923  */
1924 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1925         # No arg means accept anything (per HTTP spec)
1926         if ( !$accept ) {
1927                 return array( $def => 1.0 );
1928         }
1929
1930         $prefs = array();
1931
1932         $parts = explode( ',', $accept );
1933
1934         foreach ( $parts as $part ) {
1935                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1936                 $values = explode( ';', trim( $part ) );
1937                 $match = array();
1938                 if ( count( $values ) == 1 ) {
1939                         $prefs[$values[0]] = 1.0;
1940                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1941                         $prefs[$values[0]] = floatval( $match[1] );
1942                 }
1943         }
1944
1945         return $prefs;
1946 }
1947
1948 /**
1949  * Checks if a given MIME type matches any of the keys in the given
1950  * array. Basic wildcards are accepted in the array keys.
1951  *
1952  * Returns the matching MIME type (or wildcard) if a match, otherwise
1953  * NULL if no match.
1954  *
1955  * @param string $type
1956  * @param array $avail
1957  * @return string
1958  * @private
1959  */
1960 function mimeTypeMatch( $type, $avail ) {
1961         if ( array_key_exists( $type, $avail ) ) {
1962                 return $type;
1963         } else {
1964                 $parts = explode( '/', $type );
1965                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
1966                         return $parts[0] . '/*';
1967                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1968                         return '*/*';
1969                 } else {
1970                         return null;
1971                 }
1972         }
1973 }
1974
1975 /**
1976  * Returns the 'best' match between a client's requested internet media types
1977  * and the server's list of available types. Each list should be an associative
1978  * array of type to preference (preference is a float between 0.0 and 1.0).
1979  * Wildcards in the types are acceptable.
1980  *
1981  * @param array $cprefs Client's acceptable type list
1982  * @param array $sprefs Server's offered types
1983  * @return string
1984  *
1985  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1986  * XXX: generalize to negotiate other stuff
1987  */
1988 function wfNegotiateType( $cprefs, $sprefs ) {
1989         $combine = array();
1990
1991         foreach ( array_keys( $sprefs ) as $type ) {
1992                 $parts = explode( '/', $type );
1993                 if ( $parts[1] != '*' ) {
1994                         $ckey = mimeTypeMatch( $type, $cprefs );
1995                         if ( $ckey ) {
1996                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1997                         }
1998                 }
1999         }
2000
2001         foreach ( array_keys( $cprefs ) as $type ) {
2002                 $parts = explode( '/', $type );
2003                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2004                         $skey = mimeTypeMatch( $type, $sprefs );
2005                         if ( $skey ) {
2006                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2007                         }
2008                 }
2009         }
2010
2011         $bestq = 0;
2012         $besttype = null;
2013
2014         foreach ( array_keys( $combine ) as $type ) {
2015                 if ( $combine[$type] > $bestq ) {
2016                         $besttype = $type;
2017                         $bestq = $combine[$type];
2018                 }
2019         }
2020
2021         return $besttype;
2022 }
2023
2024 /**
2025  * Reference-counted warning suppression
2026  *
2027  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
2028  * @param bool $end
2029  */
2030 function wfSuppressWarnings( $end = false ) {
2031         MediaWiki\suppressWarnings( $end );
2032 }
2033
2034 /**
2035  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
2036  * Restore error level to previous value
2037  */
2038 function wfRestoreWarnings() {
2039         MediaWiki\suppressWarnings( true );
2040 }
2041
2042 # Autodetect, convert and provide timestamps of various types
2043
2044 /**
2045  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2046  */
2047 define( 'TS_UNIX', 0 );
2048
2049 /**
2050  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2051  */
2052 define( 'TS_MW', 1 );
2053
2054 /**
2055  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2056  */
2057 define( 'TS_DB', 2 );
2058
2059 /**
2060  * RFC 2822 format, for E-mail and HTTP headers
2061  */
2062 define( 'TS_RFC2822', 3 );
2063
2064 /**
2065  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2066  *
2067  * This is used by Special:Export
2068  */
2069 define( 'TS_ISO_8601', 4 );
2070
2071 /**
2072  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2073  *
2074  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2075  *       DateTime tag and page 36 for the DateTimeOriginal and
2076  *       DateTimeDigitized tags.
2077  */
2078 define( 'TS_EXIF', 5 );
2079
2080 /**
2081  * Oracle format time.
2082  */
2083 define( 'TS_ORACLE', 6 );
2084
2085 /**
2086  * Postgres format time.
2087  */
2088 define( 'TS_POSTGRES', 7 );
2089
2090 /**
2091  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2092  */
2093 define( 'TS_ISO_8601_BASIC', 9 );
2094
2095 /**
2096  * Get a timestamp string in one of various formats
2097  *
2098  * @param mixed $outputtype A timestamp in one of the supported formats, the
2099  *   function will autodetect which format is supplied and act accordingly.
2100  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2101  * @return string|bool String / false The same date in the format specified in $outputtype or false
2102  */
2103 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2104         try {
2105                 $timestamp = new MWTimestamp( $ts );
2106                 return $timestamp->getTimestamp( $outputtype );
2107         } catch ( TimestampException $e ) {
2108                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2109                 return false;
2110         }
2111 }
2112
2113 /**
2114  * Return a formatted timestamp, or null if input is null.
2115  * For dealing with nullable timestamp columns in the database.
2116  *
2117  * @param int $outputtype
2118  * @param string $ts
2119  * @return string
2120  */
2121 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2122         if ( is_null( $ts ) ) {
2123                 return null;
2124         } else {
2125                 return wfTimestamp( $outputtype, $ts );
2126         }
2127 }
2128
2129 /**
2130  * Convenience function; returns MediaWiki timestamp for the present time.
2131  *
2132  * @return string
2133  */
2134 function wfTimestampNow() {
2135         # return NOW
2136         return wfTimestamp( TS_MW, time() );
2137 }
2138
2139 /**
2140  * Check if the operating system is Windows
2141  *
2142  * @return bool True if it's Windows, false otherwise.
2143  */
2144 function wfIsWindows() {
2145         static $isWindows = null;
2146         if ( $isWindows === null ) {
2147                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2148         }
2149         return $isWindows;
2150 }
2151
2152 /**
2153  * Check if we are running under HHVM
2154  *
2155  * @return bool
2156  */
2157 function wfIsHHVM() {
2158         return defined( 'HHVM_VERSION' );
2159 }
2160
2161 /**
2162  * Tries to get the system directory for temporary files. First
2163  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2164  * environment variables are then checked in sequence, then
2165  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2166  *
2167  * NOTE: When possible, use instead the tmpfile() function to create
2168  * temporary files to avoid race conditions on file creation, etc.
2169  *
2170  * @return string
2171  */
2172 function wfTempDir() {
2173         global $wgTmpDirectory;
2174
2175         if ( $wgTmpDirectory !== false ) {
2176                 return $wgTmpDirectory;
2177         }
2178
2179         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2180         $tmpDir[] = sys_get_temp_dir();
2181         $tmpDir[] = ini_get( 'upload_tmp_dir' );
2182
2183         foreach ( $tmpDir as $tmp ) {
2184                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2185                         return $tmp;
2186                 }
2187         }
2188         throw new MWException( 'No writable temporary directory could be found. ' .
2189                 'Please set $wgTmpDirectory to a writable directory.' );
2190 }
2191
2192 /**
2193  * Make directory, and make all parent directories if they don't exist
2194  *
2195  * @param string $dir Full path to directory to create
2196  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2197  * @param string $caller Optional caller param for debugging.
2198  * @throws MWException
2199  * @return bool
2200  */
2201 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2202         global $wgDirectoryMode;
2203
2204         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2205                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2206         }
2207
2208         if ( !is_null( $caller ) ) {
2209                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2210         }
2211
2212         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2213                 return true;
2214         }
2215
2216         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2217
2218         if ( is_null( $mode ) ) {
2219                 $mode = $wgDirectoryMode;
2220         }
2221
2222         // Turn off the normal warning, we're doing our own below
2223         MediaWiki\suppressWarnings();
2224         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2225         MediaWiki\restoreWarnings();
2226
2227         if ( !$ok ) {
2228                 // directory may have been created on another request since we last checked
2229                 if ( is_dir( $dir ) ) {
2230                         return true;
2231                 }
2232
2233                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2234                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2235         }
2236         return $ok;
2237 }
2238
2239 /**
2240  * Remove a directory and all its content.
2241  * Does not hide error.
2242  * @param string $dir
2243  */
2244 function wfRecursiveRemoveDir( $dir ) {
2245         wfDebug( __FUNCTION__ . "( $dir )\n" );
2246         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2247         if ( is_dir( $dir ) ) {
2248                 $objects = scandir( $dir );
2249                 foreach ( $objects as $object ) {
2250                         if ( $object != "." && $object != ".." ) {
2251                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2252                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2253                                 } else {
2254                                         unlink( $dir . '/' . $object );
2255                                 }
2256                         }
2257                 }
2258                 reset( $objects );
2259                 rmdir( $dir );
2260         }
2261 }
2262
2263 /**
2264  * @param int $nr The number to format
2265  * @param int $acc The number of digits after the decimal point, default 2
2266  * @param bool $round Whether or not to round the value, default true
2267  * @return string
2268  */
2269 function wfPercent( $nr, $acc = 2, $round = true ) {
2270         $ret = sprintf( "%.${acc}f", $nr );
2271         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2272 }
2273
2274 /**
2275  * Safety wrapper around ini_get() for boolean settings.
2276  * The values returned from ini_get() are pre-normalized for settings
2277  * set via php.ini or php_flag/php_admin_flag... but *not*
2278  * for those set via php_value/php_admin_value.
2279  *
2280  * It's fairly common for people to use php_value instead of php_flag,
2281  * which can leave you with an 'off' setting giving a false positive
2282  * for code that just takes the ini_get() return value as a boolean.
2283  *
2284  * To make things extra interesting, setting via php_value accepts
2285  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2286  * Unrecognized values go false... again opposite PHP's own coercion
2287  * from string to bool.
2288  *
2289  * Luckily, 'properly' set settings will always come back as '0' or '1',
2290  * so we only have to worry about them and the 'improper' settings.
2291  *
2292  * I frickin' hate PHP... :P
2293  *
2294  * @param string $setting
2295  * @return bool
2296  */
2297 function wfIniGetBool( $setting ) {
2298         $val = strtolower( ini_get( $setting ) );
2299         // 'on' and 'true' can't have whitespace around them, but '1' can.
2300         return $val == 'on'
2301                 || $val == 'true'
2302                 || $val == 'yes'
2303                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2304 }
2305
2306 /**
2307  * Windows-compatible version of escapeshellarg()
2308  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2309  * function puts single quotes in regardless of OS.
2310  *
2311  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2312  * earlier distro releases of PHP)
2313  *
2314  * @param string ... strings to escape and glue together, or a single array of strings parameter
2315  * @return string
2316  */
2317 function wfEscapeShellArg( /*...*/ ) {
2318         wfInitShellLocale();
2319
2320         $args = func_get_args();
2321         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2322                 // If only one argument has been passed, and that argument is an array,
2323                 // treat it as a list of arguments
2324                 $args = reset( $args );
2325         }
2326
2327         $first = true;
2328         $retVal = '';
2329         foreach ( $args as $arg ) {
2330                 if ( !$first ) {
2331                         $retVal .= ' ';
2332                 } else {
2333                         $first = false;
2334                 }
2335
2336                 if ( wfIsWindows() ) {
2337                         // Escaping for an MSVC-style command line parser and CMD.EXE
2338                         // @codingStandardsIgnoreStart For long URLs
2339                         // Refs:
2340                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2341                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2342                         //  * Bug #13518
2343                         //  * CR r63214
2344                         // Double the backslashes before any double quotes. Escape the double quotes.
2345                         // @codingStandardsIgnoreEnd
2346                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2347                         $arg = '';
2348                         $iteration = 0;
2349                         foreach ( $tokens as $token ) {
2350                                 if ( $iteration % 2 == 1 ) {
2351                                         // Delimiter, a double quote preceded by zero or more slashes
2352                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2353                                 } elseif ( $iteration % 4 == 2 ) {
2354                                         // ^ in $token will be outside quotes, need to be escaped
2355                                         $arg .= str_replace( '^', '^^', $token );
2356                                 } else { // $iteration % 4 == 0
2357                                         // ^ in $token will appear inside double quotes, so leave as is
2358                                         $arg .= $token;
2359                                 }
2360                                 $iteration++;
2361                         }
2362                         // Double the backslashes before the end of the string, because
2363                         // we will soon add a quote
2364                         $m = array();
2365                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2366                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2367                         }
2368
2369                         // Add surrounding quotes
2370                         $retVal .= '"' . $arg . '"';
2371                 } else {
2372                         $retVal .= escapeshellarg( $arg );
2373                 }
2374         }
2375         return $retVal;
2376 }
2377
2378 /**
2379  * Check if wfShellExec() is effectively disabled via php.ini config
2380  *
2381  * @return bool|string False or one of (safemode,disabled)
2382  * @since 1.22
2383  */
2384 function wfShellExecDisabled() {
2385         static $disabled = null;
2386         if ( is_null( $disabled ) ) {
2387                 if ( wfIniGetBool( 'safe_mode' ) ) {
2388                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2389                         $disabled = 'safemode';
2390                 } elseif ( !function_exists( 'proc_open' ) ) {
2391                         wfDebug( "proc_open() is disabled\n" );
2392                         $disabled = 'disabled';
2393                 } else {
2394                         $disabled = false;
2395                 }
2396         }
2397         return $disabled;
2398 }
2399
2400 /**
2401  * Execute a shell command, with time and memory limits mirrored from the PHP
2402  * configuration if supported.
2403  *
2404  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2405  *   or an array of unescaped arguments, in which case each value will be escaped
2406  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2407  * @param null|mixed &$retval Optional, will receive the program's exit code.
2408  *   (non-zero is usually failure). If there is an error from
2409  *   read, select, or proc_open(), this will be set to -1.
2410  * @param array $environ Optional environment variables which should be
2411  *   added to the executed command environment.
2412  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2413  *   this overwrites the global wgMaxShell* limits.
2414  * @param array $options Array of options:
2415  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2416  *     including errors from limit.sh
2417  *   - profileMethod: By default this function will profile based on the calling
2418  *     method. Set this to a string for an alternative method to profile from
2419  *
2420  * @return string Collected stdout as a string
2421  */
2422 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2423         $limits = array(), $options = array()
2424 ) {
2425         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2426                 $wgMaxShellWallClockTime, $wgShellCgroup;
2427
2428         $disabled = wfShellExecDisabled();
2429         if ( $disabled ) {
2430                 $retval = 1;
2431                 return $disabled == 'safemode' ?
2432                         'Unable to run external programs in safe mode.' :
2433                         'Unable to run external programs, proc_open() is disabled.';
2434         }
2435
2436         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2437         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2438
2439         wfInitShellLocale();
2440
2441         $envcmd = '';
2442         foreach ( $environ as $k => $v ) {
2443                 if ( wfIsWindows() ) {
2444                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2445                          * appear in the environment variable, so we must use carat escaping as documented in
2446                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2447                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2448                          * are listed there but doesn't appear to need it.
2449                          */
2450                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2451                 } else {
2452                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2453                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2454                          */
2455                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2456                 }
2457         }
2458         if ( is_array( $cmd ) ) {
2459                 $cmd = wfEscapeShellArg( $cmd );
2460         }
2461
2462         $cmd = $envcmd . $cmd;
2463
2464         $useLogPipe = false;
2465         if ( is_executable( '/bin/bash' ) ) {
2466                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2467                 if ( isset( $limits['walltime'] ) ) {
2468                         $wallTime = intval( $limits['walltime'] );
2469                 } elseif ( isset( $limits['time'] ) ) {
2470                         $wallTime = $time;
2471                 } else {
2472                         $wallTime = intval( $wgMaxShellWallClockTime );
2473                 }
2474                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2475                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2476
2477                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2478                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2479                                 escapeshellarg( $cmd ) . ' ' .
2480                                 escapeshellarg(
2481                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2482                                         "MW_CPU_LIMIT=$time; " .
2483                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2484                                         "MW_MEM_LIMIT=$mem; " .
2485                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2486                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2487                                         "MW_USE_LOG_PIPE=yes"
2488                                 );
2489                         $useLogPipe = true;
2490                 } elseif ( $includeStderr ) {
2491                         $cmd .= ' 2>&1';
2492                 }
2493         } elseif ( $includeStderr ) {
2494                 $cmd .= ' 2>&1';
2495         }
2496         wfDebug( "wfShellExec: $cmd\n" );
2497
2498         $desc = array(
2499                 0 => array( 'file', 'php://stdin', 'r' ),
2500                 1 => array( 'pipe', 'w' ),
2501                 2 => array( 'file', 'php://stderr', 'w' ) );
2502         if ( $useLogPipe ) {
2503                 $desc[3] = array( 'pipe', 'w' );
2504         }
2505         $pipes = null;
2506         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2507         $proc = proc_open( $cmd, $desc, $pipes );
2508         if ( !$proc ) {
2509                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2510                 $retval = -1;
2511                 return '';
2512         }
2513         $outBuffer = $logBuffer = '';
2514         $emptyArray = array();
2515         $status = false;
2516         $logMsg = false;
2517
2518         /* According to the documentation, it is possible for stream_select()
2519          * to fail due to EINTR. I haven't managed to induce this in testing
2520          * despite sending various signals. If it did happen, the error
2521          * message would take the form:
2522          *
2523          * stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2524          *
2525          * where [4] is the value of the macro EINTR and "Interrupted system
2526          * call" is string which according to the Linux manual is "possibly"
2527          * localised according to LC_MESSAGES.
2528          */
2529         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2530         $eintrMessage = "stream_select(): unable to select [$eintr]";
2531
2532         // Build a table mapping resource IDs to pipe FDs to work around a
2533         // PHP 5.3 issue in which stream_select() does not preserve array keys
2534         // <https://bugs.php.net/bug.php?id=53427>.
2535         $fds = array();
2536         foreach ( $pipes as $fd => $pipe ) {
2537                 $fds[(int)$pipe] = $fd;
2538         }
2539
2540         $running = true;
2541         $timeout = null;
2542         $numReadyPipes = 0;
2543
2544         while ( $running === true || $numReadyPipes !== 0 ) {
2545                 if ( $running ) {
2546                         $status = proc_get_status( $proc );
2547                         // If the process has terminated, switch to nonblocking selects
2548                         // for getting any data still waiting to be read.
2549                         if ( !$status['running'] ) {
2550                                 $running = false;
2551                                 $timeout = 0;
2552                         }
2553                 }
2554
2555                 $readyPipes = $pipes;
2556
2557                 // Clear last error
2558                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2559                 @trigger_error( '' );
2560                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2561                 if ( $numReadyPipes === false ) {
2562                         // @codingStandardsIgnoreEnd
2563                         $error = error_get_last();
2564                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2565                                 continue;
2566                         } else {
2567                                 trigger_error( $error['message'], E_USER_WARNING );
2568                                 $logMsg = $error['message'];
2569                                 break;
2570                         }
2571                 }
2572                 foreach ( $readyPipes as $pipe ) {
2573                         $block = fread( $pipe, 65536 );
2574                         $fd = $fds[(int)$pipe];
2575                         if ( $block === '' ) {
2576                                 // End of file
2577                                 fclose( $pipes[$fd] );
2578                                 unset( $pipes[$fd] );
2579                                 if ( !$pipes ) {
2580                                         break 2;
2581                                 }
2582                         } elseif ( $block === false ) {
2583                                 // Read error
2584                                 $logMsg = "Error reading from pipe";
2585                                 break 2;
2586                         } elseif ( $fd == 1 ) {
2587                                 // From stdout
2588                                 $outBuffer .= $block;
2589                         } elseif ( $fd == 3 ) {
2590                                 // From log FD
2591                                 $logBuffer .= $block;
2592                                 if ( strpos( $block, "\n" ) !== false ) {
2593                                         $lines = explode( "\n", $logBuffer );
2594                                         $logBuffer = array_pop( $lines );
2595                                         foreach ( $lines as $line ) {
2596                                                 wfDebugLog( 'exec', $line );
2597                                         }
2598                                 }
2599                         }
2600                 }
2601         }
2602
2603         foreach ( $pipes as $pipe ) {
2604                 fclose( $pipe );
2605         }
2606
2607         // Use the status previously collected if possible, since proc_get_status()
2608         // just calls waitpid() which will not return anything useful the second time.
2609         if ( $running ) {
2610                 $status = proc_get_status( $proc );
2611         }
2612
2613         if ( $logMsg !== false ) {
2614                 // Read/select error
2615                 $retval = -1;
2616                 proc_close( $proc );
2617         } elseif ( $status['signaled'] ) {
2618                 $logMsg = "Exited with signal {$status['termsig']}";
2619                 $retval = 128 + $status['termsig'];
2620                 proc_close( $proc );
2621         } else {
2622                 if ( $status['running'] ) {
2623                         $retval = proc_close( $proc );
2624                 } else {
2625                         $retval = $status['exitcode'];
2626                         proc_close( $proc );
2627                 }
2628                 if ( $retval == 127 ) {
2629                         $logMsg = "Possibly missing executable file";
2630                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2631                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2632                 }
2633         }
2634
2635         if ( $logMsg !== false ) {
2636                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2637         }
2638
2639         return $outBuffer;
2640 }
2641
2642 /**
2643  * Execute a shell command, returning both stdout and stderr. Convenience
2644  * function, as all the arguments to wfShellExec can become unwieldy.
2645  *
2646  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2647  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2648  *   or an array of unescaped arguments, in which case each value will be escaped
2649  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2650  * @param null|mixed &$retval Optional, will receive the program's exit code.
2651  *   (non-zero is usually failure)
2652  * @param array $environ Optional environment variables which should be
2653  *   added to the executed command environment.
2654  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2655  *   this overwrites the global wgMaxShell* limits.
2656  * @return string Collected stdout and stderr as a string
2657  */
2658 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2659         return wfShellExec( $cmd, $retval, $environ, $limits,
2660                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2661 }
2662
2663 /**
2664  * Workaround for http://bugs.php.net/bug.php?id=45132
2665  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2666  */
2667 function wfInitShellLocale() {
2668         static $done = false;
2669         if ( $done ) {
2670                 return;
2671         }
2672         $done = true;
2673         global $wgShellLocale;
2674         if ( !wfIniGetBool( 'safe_mode' ) ) {
2675                 putenv( "LC_CTYPE=$wgShellLocale" );
2676                 setlocale( LC_CTYPE, $wgShellLocale );
2677         }
2678 }
2679
2680 /**
2681  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2682  * Note that $parameters should be a flat array and an option with an argument
2683  * should consist of two consecutive items in the array (do not use "--option value").
2684  *
2685  * @param string $script MediaWiki cli script path
2686  * @param array $parameters Arguments and options to the script
2687  * @param array $options Associative array of options:
2688  *              'php': The path to the php executable
2689  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2690  * @return string
2691  */
2692 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2693         global $wgPhpCli;
2694         // Give site config file a chance to run the script in a wrapper.
2695         // The caller may likely want to call wfBasename() on $script.
2696         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2697         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2698         if ( isset( $options['wrapper'] ) ) {
2699                 $cmd[] = $options['wrapper'];
2700         }
2701         $cmd[] = $script;
2702         // Escape each parameter for shell
2703         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
2704 }
2705
2706 /**
2707  * wfMerge attempts to merge differences between three texts.
2708  * Returns true for a clean merge and false for failure or a conflict.
2709  *
2710  * @param string $old
2711  * @param string $mine
2712  * @param string $yours
2713  * @param string $result
2714  * @return bool
2715  */
2716 function wfMerge( $old, $mine, $yours, &$result ) {
2717         global $wgDiff3;
2718
2719         # This check may also protect against code injection in
2720         # case of broken installations.
2721         MediaWiki\suppressWarnings();
2722         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2723         MediaWiki\restoreWarnings();
2724
2725         if ( !$haveDiff3 ) {
2726                 wfDebug( "diff3 not found\n" );
2727                 return false;
2728         }
2729
2730         # Make temporary files
2731         $td = wfTempDir();
2732         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2733         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2734         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2735
2736         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2737         #       a newline character. To avoid this, we normalize the trailing whitespace before
2738         #       creating the diff.
2739
2740         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2741         fclose( $oldtextFile );
2742         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2743         fclose( $mytextFile );
2744         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2745         fclose( $yourtextFile );
2746
2747         # Check for a conflict
2748         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
2749                 $oldtextName, $yourtextName );
2750         $handle = popen( $cmd, 'r' );
2751
2752         if ( fgets( $handle, 1024 ) ) {
2753                 $conflict = true;
2754         } else {
2755                 $conflict = false;
2756         }
2757         pclose( $handle );
2758
2759         # Merge differences
2760         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2761                 $oldtextName, $yourtextName );
2762         $handle = popen( $cmd, 'r' );
2763         $result = '';
2764         do {
2765                 $data = fread( $handle, 8192 );
2766                 if ( strlen( $data ) == 0 ) {
2767                         break;
2768                 }
2769                 $result .= $data;
2770         } while ( true );
2771         pclose( $handle );
2772         unlink( $mytextName );
2773         unlink( $oldtextName );
2774         unlink( $yourtextName );
2775
2776         if ( $result === '' && $old !== '' && !$conflict ) {
2777                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2778                 $conflict = true;
2779         }
2780         return !$conflict;
2781 }
2782
2783 /**
2784  * Returns unified plain-text diff of two texts.
2785  * "Useful" for machine processing of diffs.
2786  *
2787  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2788  *
2789  * @param string $before The text before the changes.
2790  * @param string $after The text after the changes.
2791  * @param string $params Command-line options for the diff command.
2792  * @return string Unified diff of $before and $after
2793  */
2794 function wfDiff( $before, $after, $params = '-u' ) {
2795         if ( $before == $after ) {
2796                 return '';
2797         }
2798
2799         global $wgDiff;
2800         MediaWiki\suppressWarnings();
2801         $haveDiff = $wgDiff && file_exists( $wgDiff );
2802         MediaWiki\restoreWarnings();
2803
2804         # This check may also protect against code injection in
2805         # case of broken installations.
2806         if ( !$haveDiff ) {
2807                 wfDebug( "diff executable not found\n" );
2808                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2809                 $format = new UnifiedDiffFormatter();
2810                 return $format->format( $diffs );
2811         }
2812
2813         # Make temporary files
2814         $td = wfTempDir();
2815         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2816         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2817
2818         fwrite( $oldtextFile, $before );
2819         fclose( $oldtextFile );
2820         fwrite( $newtextFile, $after );
2821         fclose( $newtextFile );
2822
2823         // Get the diff of the two files
2824         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2825
2826         $h = popen( $cmd, 'r' );
2827         if ( !$h ) {
2828                 unlink( $oldtextName );
2829                 unlink( $newtextName );
2830                 throw new Exception( __METHOD__ . '(): popen() failed' );
2831         }
2832
2833         $diff = '';
2834
2835         do {
2836                 $data = fread( $h, 8192 );
2837                 if ( strlen( $data ) == 0 ) {
2838                         break;
2839                 }
2840                 $diff .= $data;
2841         } while ( true );
2842
2843         // Clean up
2844         pclose( $h );
2845         unlink( $oldtextName );
2846         unlink( $newtextName );
2847
2848         // Kill the --- and +++ lines. They're not useful.
2849         $diff_lines = explode( "\n", $diff );
2850         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2851                 unset( $diff_lines[0] );
2852         }
2853         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2854                 unset( $diff_lines[1] );
2855         }
2856
2857         $diff = implode( "\n", $diff_lines );
2858
2859         return $diff;
2860 }
2861
2862 /**
2863  * This function works like "use VERSION" in Perl, the program will die with a
2864  * backtrace if the current version of PHP is less than the version provided
2865  *
2866  * This is useful for extensions which due to their nature are not kept in sync
2867  * with releases, and might depend on other versions of PHP than the main code
2868  *
2869  * Note: PHP might die due to parsing errors in some cases before it ever
2870  *       manages to call this function, such is life
2871  *
2872  * @see perldoc -f use
2873  *
2874  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2875  * @throws MWException
2876  */
2877 function wfUsePHP( $req_ver ) {
2878         $php_ver = PHP_VERSION;
2879
2880         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2881                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2882         }
2883 }
2884
2885 /**
2886  * This function works like "use VERSION" in Perl except it checks the version
2887  * of MediaWiki, the program will die with a backtrace if the current version
2888  * of MediaWiki is less than the version provided.
2889  *
2890  * This is useful for extensions which due to their nature are not kept in sync
2891  * with releases
2892  *
2893  * Note: Due to the behavior of PHP's version_compare() which is used in this
2894  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2895  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2896  * targeted version number. For example if you wanted to allow any variation
2897  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2898  * not result in the same comparison due to the internal logic of
2899  * version_compare().
2900  *
2901  * @see perldoc -f use
2902  *
2903  * @deprecated since 1.26, use the "requires' property of extension.json
2904  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2905  * @throws MWException
2906  */
2907 function wfUseMW( $req_ver ) {
2908         global $wgVersion;
2909
2910         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2911                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2912         }
2913 }
2914
2915 /**
2916  * Return the final portion of a pathname.
2917  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2918  * http://bugs.php.net/bug.php?id=33898
2919  *
2920  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2921  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2922  *
2923  * @param string $path
2924  * @param string $suffix String to remove if present
2925  * @return string
2926  */
2927 function wfBaseName( $path, $suffix = '' ) {
2928         if ( $suffix == '' ) {
2929                 $encSuffix = '';
2930         } else {
2931                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2932         }
2933
2934         $matches = array();
2935         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2936                 return $matches[1];
2937         } else {
2938                 return '';
2939         }
2940 }
2941
2942 /**
2943  * Generate a relative path name to the given file.
2944  * May explode on non-matching case-insensitive paths,
2945  * funky symlinks, etc.
2946  *
2947  * @param string $path Absolute destination path including target filename
2948  * @param string $from Absolute source path, directory only
2949  * @return string
2950  */
2951 function wfRelativePath( $path, $from ) {
2952         // Normalize mixed input on Windows...
2953         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2954         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2955
2956         // Trim trailing slashes -- fix for drive root
2957         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2958         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2959
2960         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2961         $against = explode( DIRECTORY_SEPARATOR, $from );
2962
2963         if ( $pieces[0] !== $against[0] ) {
2964                 // Non-matching Windows drive letters?
2965                 // Return a full path.
2966                 return $path;
2967         }
2968
2969         // Trim off common prefix
2970         while ( count( $pieces ) && count( $against )
2971                 && $pieces[0] == $against[0] ) {
2972                 array_shift( $pieces );
2973                 array_shift( $against );
2974         }
2975
2976         // relative dots to bump us to the parent
2977         while ( count( $against ) ) {
2978                 array_unshift( $pieces, '..' );
2979                 array_shift( $against );
2980         }
2981
2982         array_push( $pieces, wfBaseName( $path ) );
2983
2984         return implode( DIRECTORY_SEPARATOR, $pieces );
2985 }
2986
2987 /**
2988  * Convert an arbitrarily-long digit string from one numeric base
2989  * to another, optionally zero-padding to a minimum column width.
2990  *
2991  * Supports base 2 through 36; digit values 10-36 are represented
2992  * as lowercase letters a-z. Input is case-insensitive.
2993  *
2994  * @deprecated 1.27 Use Wikimedia\base_convert() directly
2995  *
2996  * @param string $input Input number
2997  * @param int $sourceBase Base of the input number
2998  * @param int $destBase Desired base of the output
2999  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3000  * @param bool $lowercase Whether to output in lowercase or uppercase
3001  * @param string $engine Either "gmp", "bcmath", or "php"
3002  * @return string|bool The output number as a string, or false on error
3003  */
3004 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3005         $lowercase = true, $engine = 'auto'
3006 ) {
3007         return Wikimedia\base_convert( $input, $sourceBase, $destBase, $pad, $lowercase, $engine );
3008 }
3009
3010 /**
3011  * Check if there is sufficient entropy in php's built-in session generation
3012  *
3013  * @return bool True = there is sufficient entropy
3014  */
3015 function wfCheckEntropy() {
3016         return (
3017                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3018                         || ini_get( 'session.entropy_file' )
3019                 )
3020                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3021 }
3022
3023 /**
3024  * Override session_id before session startup if php's built-in
3025  * session generation code is not secure.
3026  */
3027 function wfFixSessionID() {
3028         // If the cookie or session id is already set we already have a session and should abort
3029         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3030                 return;
3031         }
3032
3033         // PHP's built-in session entropy is enabled if:
3034         // - entropy_file is set or you're on Windows with php 5.3.3+
3035         // - AND entropy_length is > 0
3036         // We treat it as disabled if it doesn't have an entropy length of at least 32
3037         $entropyEnabled = wfCheckEntropy();
3038
3039         // If built-in entropy is not enabled or not sufficient override PHP's
3040         // built in session id generation code
3041         if ( !$entropyEnabled ) {
3042                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3043                         "overriding session id generation using our cryptrand source.\n" );
3044                 session_id( MWCryptRand::generateHex( 32 ) );
3045         }
3046 }
3047
3048 /**
3049  * Reset the session_id
3050  *
3051  * @since 1.22
3052  */
3053 function wfResetSessionID() {
3054         global $wgCookieSecure;
3055         $oldSessionId = session_id();
3056         $cookieParams = session_get_cookie_params();
3057         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3058                 session_regenerate_id( false );
3059         } else {
3060                 $tmp = $_SESSION;
3061                 session_destroy();
3062                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3063                 $_SESSION = $tmp;
3064         }
3065         $newSessionId = session_id();
3066 }
3067
3068 /**
3069  * Initialise php session
3070  *
3071  * @param bool $sessionId
3072  */
3073 function wfSetupSession( $sessionId = false ) {
3074         global $wgSessionsInObjectCache, $wgSessionHandler;
3075         global $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly;
3076
3077         if ( $wgSessionsInObjectCache ) {
3078                 ObjectCacheSessionHandler::install();
3079         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3080                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3081                 # hasn't already been set to the desired value (that causes errors)
3082                 ini_set( 'session.save_handler', $wgSessionHandler );
3083         }
3084
3085         session_set_cookie_params(
3086                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3087         session_cache_limiter( 'private, must-revalidate' );
3088         if ( $sessionId ) {
3089                 session_id( $sessionId );
3090         } else {
3091                 wfFixSessionID();
3092         }
3093
3094         MediaWiki\suppressWarnings();
3095         session_start();
3096         MediaWiki\restoreWarnings();
3097
3098         if ( $wgSessionsInObjectCache ) {
3099                 ObjectCacheSessionHandler::renewCurrentSession();
3100         }
3101 }
3102
3103 /**
3104  * Get an object from the precompiled serialized directory
3105  *
3106  * @param string $name
3107  * @return mixed The variable on success, false on failure
3108  */
3109 function wfGetPrecompiledData( $name ) {
3110         global $IP;
3111
3112         $file = "$IP/serialized/$name";
3113         if ( file_exists( $file ) ) {
3114                 $blob = file_get_contents( $file );
3115                 if ( $blob ) {
3116                         return unserialize( $blob );
3117                 }
3118         }
3119         return false;
3120 }
3121
3122 /**
3123  * Make a cache key for the local wiki.
3124  *
3125  * @param string $args,...
3126  * @return string
3127  */
3128 function wfMemcKey( /*...*/ ) {
3129         return call_user_func_array(
3130                 array( ObjectCache::getLocalClusterInstance(), 'makeKey' ),
3131                 func_get_args()
3132         );
3133 }
3134
3135 /**
3136  * Make a cache key for a foreign DB.
3137  *
3138  * Must match what wfMemcKey() would produce in context of the foreign wiki.
3139  *
3140  * @param string $db
3141  * @param string $prefix
3142  * @param string $args,...
3143  * @return string
3144  */
3145 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3146         $args = array_slice( func_get_args(), 2 );
3147         $keyspace = $prefix ? "$db-$prefix" : $db;
3148         return call_user_func_array(
3149                 array( ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ),
3150                 array( $keyspace, $args )
3151         );
3152 }
3153
3154 /**
3155  * Make a cache key with database-agnostic prefix.
3156  *
3157  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3158  * instead. Must have a prefix as otherwise keys that use a database name
3159  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3160  *
3161  * @since 1.26
3162  * @param string $args,...
3163  * @return string
3164  */
3165 function wfGlobalCacheKey( /*...*/ ) {
3166         return call_user_func_array(
3167                 array( ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ),
3168                 func_get_args()
3169         );
3170 }
3171
3172 /**
3173  * Get an ASCII string identifying this wiki
3174  * This is used as a prefix in memcached keys
3175  *
3176  * @return string
3177  */
3178 function wfWikiID() {
3179         global $wgDBprefix, $wgDBname;
3180         if ( $wgDBprefix ) {
3181                 return "$wgDBname-$wgDBprefix";
3182         } else {
3183                 return $wgDBname;
3184         }
3185 }
3186
3187 /**
3188  * Split a wiki ID into DB name and table prefix
3189  *
3190  * @param string $wiki
3191  *
3192  * @return array
3193  */
3194 function wfSplitWikiID( $wiki ) {
3195         $bits = explode( '-', $wiki, 2 );
3196         if ( count( $bits ) < 2 ) {
3197                 $bits[] = '';
3198         }
3199         return $bits;
3200 }
3201
3202 /**
3203  * Get a Database object.
3204  *
3205  * @param int $db Index of the connection to get. May be DB_MASTER for the
3206  *            master (for write queries), DB_SLAVE for potentially lagged read
3207  *            queries, or an integer >= 0 for a particular server.
3208  *
3209  * @param string|string[] $groups Query groups. An array of group names that this query
3210  *                belongs to. May contain a single string if the query is only
3211  *                in one group.
3212  *
3213  * @param string|bool $wiki The wiki ID, or false for the current wiki
3214  *
3215  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3216  * will always return the same object, unless the underlying connection or load
3217  * balancer is manually destroyed.
3218  *
3219  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3220  * updater to ensure that a proper database is being updated.
3221  *
3222  * @return DatabaseBase
3223  */
3224 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3225         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3226 }
3227
3228 /**
3229  * Get a load balancer object.
3230  *
3231  * @param string|bool $wiki Wiki ID, or false for the current wiki
3232  * @return LoadBalancer
3233  */
3234 function wfGetLB( $wiki = false ) {
3235         return wfGetLBFactory()->getMainLB( $wiki );
3236 }
3237
3238 /**
3239  * Get the load balancer factory object
3240  *
3241  * @return LBFactory
3242  */
3243 function wfGetLBFactory() {
3244         return LBFactory::singleton();
3245 }
3246
3247 /**
3248  * Find a file.
3249  * Shortcut for RepoGroup::singleton()->findFile()
3250  *
3251  * @param string $title String or Title object
3252  * @param array $options Associative array of options (see RepoGroup::findFile)
3253  * @return File|bool File, or false if the file does not exist
3254  */
3255 function wfFindFile( $title, $options = array() ) {
3256         return RepoGroup::singleton()->findFile( $title, $options );
3257 }
3258
3259 /**
3260  * Get an object referring to a locally registered file.
3261  * Returns a valid placeholder object if the file does not exist.
3262  *
3263  * @param Title|string $title
3264  * @return LocalFile|null A File, or null if passed an invalid Title
3265  */
3266 function wfLocalFile( $title ) {
3267         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3268 }
3269
3270 /**
3271  * Should low-performance queries be disabled?
3272  *
3273  * @return bool
3274  * @codeCoverageIgnore
3275  */
3276 function wfQueriesMustScale() {
3277         global $wgMiserMode;
3278         return $wgMiserMode
3279                 || ( SiteStats::pages() > 100000
3280                 && SiteStats::edits() > 1000000
3281                 && SiteStats::users() > 10000 );
3282 }
3283
3284 /**
3285  * Get the path to a specified script file, respecting file
3286  * extensions; this is a wrapper around $wgScriptPath etc.
3287  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3288  *
3289  * @param string $script Script filename, sans extension
3290  * @return string
3291  */
3292 function wfScript( $script = 'index' ) {
3293         global $wgScriptPath, $wgScript, $wgLoadScript;
3294         if ( $script === 'index' ) {
3295                 return $wgScript;
3296         } elseif ( $script === 'load' ) {
3297                 return $wgLoadScript;
3298         } else {
3299                 return "{$wgScriptPath}/{$script}.php";
3300         }
3301 }
3302
3303 /**
3304  * Get the script URL.
3305  *
3306  * @return string Script URL
3307  */
3308 function wfGetScriptUrl() {
3309         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3310                 /* as it was called, minus the query string.
3311                  *
3312                  * Some sites use Apache rewrite rules to handle subdomains,
3313                  * and have PHP set up in a weird way that causes PHP_SELF
3314                  * to contain the rewritten URL instead of the one that the
3315                  * outside world sees.
3316                  *
3317                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
3318                  * provides containing the "before" URL.
3319                  */
3320                 return $_SERVER['SCRIPT_NAME'];
3321         } else {
3322                 return $_SERVER['URL'];
3323         }
3324 }
3325
3326 /**
3327  * Convenience function converts boolean values into "true"
3328  * or "false" (string) values
3329  *
3330  * @param bool $value
3331  * @return string
3332  */
3333 function wfBoolToStr( $value ) {
3334         return $value ? 'true' : 'false';
3335 }
3336
3337 /**
3338  * Get a platform-independent path to the null file, e.g. /dev/null
3339  *
3340  * @return string
3341  */
3342 function wfGetNull() {
3343         return wfIsWindows() ? 'NUL' : '/dev/null';
3344 }
3345
3346 /**
3347  * Waits for the slaves to catch up to the master position
3348  *
3349  * Use this when updating very large numbers of rows, as in maintenance scripts,
3350  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3351  *
3352  * By default this waits on the main DB cluster of the current wiki.
3353  * If $cluster is set to "*" it will wait on all DB clusters, including
3354  * external ones. If the lag being waiting on is caused by the code that
3355  * does this check, it makes since to use $ifWritesSince, particularly if
3356  * cluster is "*", to avoid excess overhead.
3357  *
3358  * Never call this function after a big DB write that is still in a transaction.
3359  * This only makes sense after the possible lag inducing changes were committed.
3360  *
3361  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3362  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3363  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3364  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3365  * @return bool Success (able to connect and no timeouts reached)
3366  * @deprecated since 1.27 Use LBFactory::waitForReplication
3367  */
3368 function wfWaitForSlaves(
3369         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3370 ) {
3371         if ( $timeout === null ) {
3372                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3373         }
3374
3375         if ( $cluster === '*' ) {
3376                 $cluster = false;
3377                 $wiki = false;
3378         } elseif ( $wiki === false ) {
3379                 $wiki = wfWikiID();
3380         }
3381
3382         try {
3383                 wfGetLBFactory()->waitForReplication( array(
3384                         'wiki' => $wiki,
3385                         'cluster' => $cluster,
3386                         'timeout' => $timeout,
3387                         // B/C: first argument used to be "max seconds of lag"; ignore such values
3388                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
3389                 ) );
3390         } catch ( DBReplicationWaitError $e ) {
3391                 return false;
3392         }
3393
3394         return true;
3395 }
3396
3397 /**
3398  * Count down from $seconds to zero on the terminal, with a one-second pause
3399  * between showing each number. For use in command-line scripts.
3400  *
3401  * @codeCoverageIgnore
3402  * @param int $seconds
3403  */
3404 function wfCountDown( $seconds ) {
3405         for ( $i = $seconds; $i >= 0; $i-- ) {
3406                 if ( $i != $seconds ) {
3407                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3408                 }
3409                 echo $i;
3410                 flush();
3411                 if ( $i ) {
3412                         sleep( 1 );
3413                 }
3414         }
3415         echo "\n";
3416 }
3417
3418 /**
3419  * Replace all invalid characters with -
3420  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3421  * By default, $wgIllegalFileChars = ':'
3422  *
3423  * @param string $name Filename to process
3424  * @return string
3425  */
3426 function wfStripIllegalFilenameChars( $name ) {
3427         global $wgIllegalFileChars;
3428         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3429         $name = wfBaseName( $name );
3430         $name = preg_replace(
3431                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3432                 '-',
3433                 $name
3434         );
3435         return $name;
3436 }
3437
3438 /**
3439  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3440  *
3441  * @return int Resulting value of the memory limit.
3442  */
3443 function wfMemoryLimit() {
3444         global $wgMemoryLimit;
3445         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3446         if ( $memlimit != -1 ) {
3447                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3448                 if ( $conflimit == -1 ) {
3449                         wfDebug( "Removing PHP's memory limit\n" );
3450                         MediaWiki\suppressWarnings();
3451                         ini_set( 'memory_limit', $conflimit );
3452                         MediaWiki\restoreWarnings();
3453                         return $conflimit;
3454                 } elseif ( $conflimit > $memlimit ) {
3455                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3456                         MediaWiki\suppressWarnings();
3457                         ini_set( 'memory_limit', $conflimit );
3458                         MediaWiki\restoreWarnings();
3459                         return $conflimit;
3460                 }
3461         }
3462         return $memlimit;
3463 }
3464
3465 /**
3466  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3467  *
3468  * @return int Prior time limit
3469  * @since 1.26
3470  */
3471 function wfTransactionalTimeLimit() {
3472         global $wgTransactionalTimeLimit;
3473
3474         $timeLimit = ini_get( 'max_execution_time' );
3475         // Note that CLI scripts use 0
3476         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3477                 set_time_limit( $wgTransactionalTimeLimit );
3478         }
3479
3480         ignore_user_abort( true ); // ignore client disconnects
3481
3482         return $timeLimit;
3483 }
3484
3485 /**
3486  * Converts shorthand byte notation to integer form
3487  *
3488  * @param string $string
3489  * @param int $default Returned if $string is empty
3490  * @return int
3491  */
3492 function wfShorthandToInteger( $string = '', $default = -1 ) {
3493         $string = trim( $string );
3494         if ( $string === '' ) {
3495                 return $default;
3496         }
3497         $last = $string[strlen( $string ) - 1];
3498         $val = intval( $string );
3499         switch ( $last ) {
3500                 case 'g':
3501                 case 'G':
3502                         $val *= 1024;
3503                         // break intentionally missing
3504                 case 'm':
3505                 case 'M':
3506                         $val *= 1024;
3507                         // break intentionally missing
3508                 case 'k':
3509                 case 'K':
3510                         $val *= 1024;
3511         }
3512
3513         return $val;
3514 }
3515
3516 /**
3517  * Get the normalised IETF language tag
3518  * See unit test for examples.
3519  *
3520  * @param string $code The language code.
3521  * @return string The language code which complying with BCP 47 standards.
3522  */
3523 function wfBCP47( $code ) {
3524         $codeSegment = explode( '-', $code );
3525         $codeBCP = array();
3526         foreach ( $codeSegment as $segNo => $seg ) {
3527                 // when previous segment is x, it is a private segment and should be lc
3528                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3529                         $codeBCP[$segNo] = strtolower( $seg );
3530                 // ISO 3166 country code
3531                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3532                         $codeBCP[$segNo] = strtoupper( $seg );
3533                 // ISO 15924 script code
3534                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3535                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3536                 // Use lowercase for other cases
3537                 } else {
3538                         $codeBCP[$segNo] = strtolower( $seg );
3539                 }
3540         }
3541         $langCode = implode( '-', $codeBCP );
3542         return $langCode;
3543 }
3544
3545 /**
3546  * Get a specific cache object.
3547  *
3548  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3549  * @return BagOStuff
3550  */
3551 function wfGetCache( $cacheType ) {
3552         return ObjectCache::getInstance( $cacheType );
3553 }
3554
3555 /**
3556  * Get the main cache object
3557  *
3558  * @return BagOStuff
3559  */
3560 function wfGetMainCache() {
3561         global $wgMainCacheType;
3562         return ObjectCache::getInstance( $wgMainCacheType );
3563 }
3564
3565 /**
3566  * Get the cache object used by the message cache
3567  *
3568  * @return BagOStuff
3569  */
3570 function wfGetMessageCacheStorage() {
3571         global $wgMessageCacheType;
3572         return ObjectCache::getInstance( $wgMessageCacheType );
3573 }
3574
3575 /**
3576  * Get the cache object used by the parser cache
3577  *
3578  * @return BagOStuff
3579  */
3580 function wfGetParserCacheStorage() {
3581         global $wgParserCacheType;
3582         return ObjectCache::getInstance( $wgParserCacheType );
3583 }
3584
3585 /**
3586  * Call hook functions defined in $wgHooks
3587  *
3588  * @param string $event Event name
3589  * @param array $args Parameters passed to hook functions
3590  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3591  *
3592  * @return bool True if no handler aborted the hook
3593  * @deprecated 1.25 - use Hooks::run
3594  */
3595 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3596         return Hooks::run( $event, $args, $deprecatedVersion );
3597 }
3598
3599 /**
3600  * Wrapper around php's unpack.
3601  *
3602  * @param string $format The format string (See php's docs)
3603  * @param string $data A binary string of binary data
3604  * @param int|bool $length The minimum length of $data or false. This is to
3605  *      prevent reading beyond the end of $data. false to disable the check.
3606  *
3607  * Also be careful when using this function to read unsigned 32 bit integer
3608  * because php might make it negative.
3609  *
3610  * @throws MWException If $data not long enough, or if unpack fails
3611  * @return array Associative array of the extracted data
3612  */
3613 function wfUnpack( $format, $data, $length = false ) {
3614         if ( $length !== false ) {
3615                 $realLen = strlen( $data );
3616                 if ( $realLen < $length ) {
3617                         throw new MWException( "Tried to use wfUnpack on a "
3618                                 . "string of length $realLen, but needed one "
3619                                 . "of at least length $length."
3620                         );
3621                 }
3622         }
3623
3624         MediaWiki\suppressWarnings();
3625         $result = unpack( $format, $data );
3626         MediaWiki\restoreWarnings();
3627
3628         if ( $result === false ) {
3629                 // If it cannot extract the packed data.
3630                 throw new MWException( "unpack could not unpack binary data" );
3631         }
3632         return $result;
3633 }
3634
3635 /**
3636  * Determine if an image exists on the 'bad image list'.
3637  *
3638  * The format of MediaWiki:Bad_image_list is as follows:
3639  *    * Only list items (lines starting with "*") are considered
3640  *    * The first link on a line must be a link to a bad image
3641  *    * Any subsequent links on the same line are considered to be exceptions,
3642  *      i.e. articles where the image may occur inline.
3643  *
3644  * @param string $name The image name to check
3645  * @param Title|bool $contextTitle The page on which the image occurs, if known
3646  * @param string $blacklist Wikitext of a file blacklist
3647  * @return bool
3648  */
3649 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3650         # Handle redirects; callers almost always hit wfFindFile() anyway,
3651         # so just use that method because it has a fast process cache.
3652         $file = wfFindFile( $name ); // get the final name
3653         $name = $file ? $file->getTitle()->getDBkey() : $name;
3654
3655         # Run the extension hook
3656         $bad = false;
3657         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
3658                 return $bad;
3659         }
3660
3661         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3662         $key = wfMemcKey( 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist ) );
3663         $badImages = $cache->get( $key );
3664
3665         if ( $badImages === false ) { // cache miss
3666                 if ( $blacklist === null ) {
3667                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3668                 }
3669                 # Build the list now
3670                 $badImages = array();
3671                 $lines = explode( "\n", $blacklist );
3672                 foreach ( $lines as $line ) {
3673                         # List items only
3674                         if ( substr( $line, 0, 1 ) !== '*' ) {
3675                                 continue;
3676                         }
3677
3678                         # Find all links
3679                         $m = array();
3680                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3681                                 continue;
3682                         }
3683
3684                         $exceptions = array();
3685                         $imageDBkey = false;
3686                         foreach ( $m[1] as $i => $titleText ) {
3687                                 $title = Title::newFromText( $titleText );
3688                                 if ( !is_null( $title ) ) {
3689                                         if ( $i == 0 ) {
3690                                                 $imageDBkey = $title->getDBkey();
3691                                         } else {
3692                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3693                                         }
3694                                 }
3695                         }
3696
3697                         if ( $imageDBkey !== false ) {
3698                                 $badImages[$imageDBkey] = $exceptions;
3699                         }
3700                 }
3701                 $cache->set( $key, $badImages, 60 );
3702         }
3703
3704         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3705         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3706
3707         return $bad;
3708 }
3709
3710 /**
3711  * Determine whether the client at a given source IP is likely to be able to
3712  * access the wiki via HTTPS.
3713  *
3714  * @param string $ip The IPv4/6 address in the normal human-readable form
3715  * @return bool
3716  */
3717 function wfCanIPUseHTTPS( $ip ) {
3718         $canDo = true;
3719         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
3720         return !!$canDo;
3721 }
3722
3723 /**
3724  * Determine input string is represents as infinity
3725  *
3726  * @param string $str The string to determine
3727  * @return bool
3728  * @since 1.25
3729  */
3730 function wfIsInfinity( $str ) {
3731         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
3732         return in_array( $str, $infinityValues );
3733 }
3734
3735 /**
3736  * Returns true if these thumbnail parameters match one that MediaWiki
3737  * requests from file description pages and/or parser output.
3738  *
3739  * $params is considered non-standard if they involve a non-standard
3740  * width or any non-default parameters aside from width and page number.
3741  * The number of possible files with standard parameters is far less than
3742  * that of all combinations; rate-limiting for them can thus be more generious.
3743  *
3744  * @param File $file
3745  * @param array $params
3746  * @return bool
3747  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3748  */
3749 function wfThumbIsStandard( File $file, array $params ) {
3750         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3751
3752         $multipliers = array( 1 );
3753         if ( $wgResponsiveImages ) {
3754                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3755                 // @see Linker::processResponsiveImages
3756                 $multipliers[] = 1.5;
3757                 $multipliers[] = 2;
3758         }
3759
3760         $handler = $file->getHandler();
3761         if ( !$handler || !isset( $params['width'] ) ) {
3762                 return false;
3763         }
3764
3765         $basicParams = array();
3766         if ( isset( $params['page'] ) ) {
3767                 $basicParams['page'] = $params['page'];
3768         }
3769
3770         $thumbLimits = array();
3771         $imageLimits = array();
3772         // Expand limits to account for multipliers
3773         foreach ( $multipliers as $multiplier ) {
3774                 $thumbLimits = array_merge( $thumbLimits, array_map(
3775                         function ( $width ) use ( $multiplier ) {
3776                                 return round( $width * $multiplier );
3777                         }, $wgThumbLimits )
3778                 );
3779                 $imageLimits = array_merge( $imageLimits, array_map(
3780                         function ( $pair ) use ( $multiplier ) {
3781                                 return array(
3782                                         round( $pair[0] * $multiplier ),
3783                                         round( $pair[1] * $multiplier ),
3784                                 );
3785                         }, $wgImageLimits )
3786                 );
3787         }
3788
3789         // Check if the width matches one of $wgThumbLimits
3790         if ( in_array( $params['width'], $thumbLimits ) ) {
3791                 $normalParams = $basicParams + array( 'width' => $params['width'] );
3792                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3793                 $handler->normaliseParams( $file, $normalParams );
3794         } else {
3795                 // If not, then check if the width matchs one of $wgImageLimits
3796                 $match = false;
3797                 foreach ( $imageLimits as $pair ) {
3798                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
3799                         // Decide whether the thumbnail should be scaled on width or height.
3800                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3801                         $handler->normaliseParams( $file, $normalParams );
3802                         // Check if this standard thumbnail size maps to the given width
3803                         if ( $normalParams['width'] == $params['width'] ) {
3804                                 $match = true;
3805                                 break;
3806                         }
3807                 }
3808                 if ( !$match ) {
3809                         return false; // not standard for description pages
3810                 }
3811         }
3812
3813         // Check that the given values for non-page, non-width, params are just defaults
3814         foreach ( $params as $key => $value ) {
3815                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3816                         return false;
3817                 }
3818         }
3819
3820         return true;
3821 }
3822
3823 /**
3824  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3825  *
3826  * Values that exist in both values will be combined with += (all values of the array
3827  * of $newValues will be added to the values of the array of $baseArray, while values,
3828  * that exists in both, the value of $baseArray will be used).
3829  *
3830  * @param array $baseArray The array where you want to add the values of $newValues to
3831  * @param array $newValues An array with new values
3832  * @return array The combined array
3833  * @since 1.26
3834  */
3835 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3836         // First merge items that are in both arrays
3837         foreach ( $baseArray as $name => &$groupVal ) {
3838                 if ( isset( $newValues[$name] ) ) {
3839                         $groupVal += $newValues[$name];
3840                 }
3841         }
3842         // Now add items that didn't exist yet
3843         $baseArray += $newValues;
3844
3845         return $baseArray;
3846 }