includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 use Liuggio\StatsdClient\Sender\SocketSender;
  28 use MediaWiki\Logger\LoggerFactory;
  29 use MediaWiki\Session\SessionManager;
  30
  31 // Hide compatibility functions from Doxygen
  32 /// @cond
  33
  34 /**
  35  * Compatibility functions
  36  *
  37  * We support PHP 5.3.3 and up.
  38  * Re-implementations of newer functions or functions in non-standard
  39  * PHP extensions may be included here.
  40  */
  41
  42 if ( !function_exists( 'mb_substr' ) ) {
  43         /**
  44          * @codeCoverageIgnore
  45          * @see Fallback::mb_substr
  46          * @return string
  47          */
  48         function mb_substr( $str, $start, $count = 'end' ) {
  49                 return Fallback::mb_substr( $str, $start, $count );
  50         }
  51
  52         /**
  53          * @codeCoverageIgnore
  54          * @see Fallback::mb_substr_split_unicode
  55          * @return int
  56          */
  57         function mb_substr_split_unicode( $str, $splitPos ) {
  58                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  59         }
  60 }
  61
  62 if ( !function_exists( 'mb_strlen' ) ) {
  63         /**
  64          * @codeCoverageIgnore
  65          * @see Fallback::mb_strlen
  66          * @return int
  67          */
  68         function mb_strlen( $str, $enc = '' ) {
  69                 return Fallback::mb_strlen( $str, $enc );
  70         }
  71 }
  72
  73 if ( !function_exists( 'mb_strpos' ) ) {
  74         /**
  75          * @codeCoverageIgnore
  76          * @see Fallback::mb_strpos
  77          * @return int
  78          */
  79         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  80                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  81         }
  82 }
  83
  84 if ( !function_exists( 'mb_strrpos' ) ) {
  85         /**
  86          * @codeCoverageIgnore
  87          * @see Fallback::mb_strrpos
  88          * @return int
  89          */
  90         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  91                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  92         }
  93 }
  94
  95 // gzdecode function only exists in PHP >= 5.4.0
  96 // http://php.net/gzdecode
  97 if ( !function_exists( 'gzdecode' ) ) {
  98         /**
  99          * @codeCoverageIgnore
 100          * @param string $data
 101          * @return string
 102          */
 103         function gzdecode( $data ) {
 104                 return gzinflate( substr( $data, 10, -8 ) );
 105         }
 106 }
 107
 108 // hash_equals function only exists in PHP >= 5.6.0
 109 // http://php.net/hash_equals
 110 if ( !function_exists( 'hash_equals' ) ) {
 111         /**
 112          * Check whether a user-provided string is equal to a fixed-length secret string
 113          * without revealing bytes of the secret string through timing differences.
 114          *
 115          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 116          * function in C) is to compare corresponding bytes and stop at the first difference,
 117          * which would take longer for a partial match than for a complete mismatch. This
 118          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 119          * and the other may come from an attacker. Statistical analysis of timing measurements
 120          * over many requests may allow the attacker to guess the string's bytes one at a time
 121          * (and check his guesses) even if the timing differences are extremely small.
 122          *
 123          * When making such a security-sensitive comparison, it is essential that the sequence
 124          * in which instructions are executed and memory locations are accessed not depend on
 125          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 126          * the inevitable leakage of the string's length. That is generally known anyway as
 127          * a chararacteristic of the hash function used to compute the secret value.
 128          *
 129          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 130          *
 131          * @codeCoverageIgnore
 132          * @param string $known_string Fixed-length secret string to compare against
 133          * @param string $user_string User-provided string
 134          * @return bool True if the strings are the same, false otherwise
 135          */
 136         function hash_equals( $known_string, $user_string ) {
 137                 // Strict type checking as in PHP's native implementation
 138                 if ( !is_string( $known_string ) ) {
 139                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 140                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 141
 142                         return false;
 143                 }
 144
 145                 if ( !is_string( $user_string ) ) {
 146                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 147                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 148
 149                         return false;
 150                 }
 151
 152                 $known_string_len = strlen( $known_string );
 153                 if ( $known_string_len !== strlen( $user_string ) ) {
 154                         return false;
 155                 }
 156
 157                 $result = 0;
 158                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 159                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 160                 }
 161
 162                 return ( $result === 0 );
 163         }
 164 }
 165 /// @endcond
 166
 167 /**
 168  * Load an extension
 169  *
 170  * This queues an extension to be loaded through
 171  * the ExtensionRegistry system.
 172  *
 173  * @param string $ext Name of the extension to load
 174  * @param string|null $path Absolute path of where to find the extension.json file
 175  * @since 1.25
 176  */
 177 function wfLoadExtension( $ext, $path = null ) {
 178         if ( !$path ) {
 179                 global $wgExtensionDirectory;
 180                 $path = "$wgExtensionDirectory/$ext/extension.json";
 181         }
 182         ExtensionRegistry::getInstance()->queue( $path );
 183 }
 184
 185 /**
 186  * Load multiple extensions at once
 187  *
 188  * Same as wfLoadExtension, but more efficient if you
 189  * are loading multiple extensions.
 190  *
 191  * If you want to specify custom paths, you should interact with
 192  * ExtensionRegistry directly.
 193  *
 194  * @see wfLoadExtension
 195  * @param string[] $exts Array of extension names to load
 196  * @since 1.25
 197  */
 198 function wfLoadExtensions( array $exts ) {
 199         global $wgExtensionDirectory;
 200         $registry = ExtensionRegistry::getInstance();
 201         foreach ( $exts as $ext ) {
 202                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 203         }
 204 }
 205
 206 /**
 207  * Load a skin
 208  *
 209  * @see wfLoadExtension
 210  * @param string $skin Name of the extension to load
 211  * @param string|null $path Absolute path of where to find the skin.json file
 212  * @since 1.25
 213  */
 214 function wfLoadSkin( $skin, $path = null ) {
 215         if ( !$path ) {
 216                 global $wgStyleDirectory;
 217                 $path = "$wgStyleDirectory/$skin/skin.json";
 218         }
 219         ExtensionRegistry::getInstance()->queue( $path );
 220 }
 221
 222 /**
 223  * Load multiple skins at once
 224  *
 225  * @see wfLoadExtensions
 226  * @param string[] $skins Array of extension names to load
 227  * @since 1.25
 228  */
 229 function wfLoadSkins( array $skins ) {
 230         global $wgStyleDirectory;
 231         $registry = ExtensionRegistry::getInstance();
 232         foreach ( $skins as $skin ) {
 233                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 234         }
 235 }
 236
 237 /**
 238  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 239  * @param array $a
 240  * @param array $b
 241  * @return array
 242  */
 243 function wfArrayDiff2( $a, $b ) {
 244         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 245 }
 246
 247 /**
 248  * @param array|string $a
 249  * @param array|string $b
 250  * @return int
 251  */
 252 function wfArrayDiff2_cmp( $a, $b ) {
 253         if ( is_string( $a ) && is_string( $b ) ) {
 254                 return strcmp( $a, $b );
 255         } elseif ( count( $a ) !== count( $b ) ) {
 256                 return count( $a ) < count( $b ) ? -1 : 1;
 257         } else {
 258                 reset( $a );
 259                 reset( $b );
 260                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 261                         $cmp = strcmp( $valueA, $valueB );
 262                         if ( $cmp !== 0 ) {
 263                                 return $cmp;
 264                         }
 265                 }
 266                 return 0;
 267         }
 268 }
 269
 270 /**
 271  * Appends to second array if $value differs from that in $default
 272  *
 273  * @param string|int $key
 274  * @param mixed $value
 275  * @param mixed $default
 276  * @param array $changed Array to alter
 277  * @throws MWException
 278  */
 279 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 280         if ( is_null( $changed ) ) {
 281                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 282         }
 283         if ( $default[$key] !== $value ) {
 284                 $changed[$key] = $value;
 285         }
 286 }
 287
 288 /**
 289  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 290  * e.g.
 291  *      wfMergeErrorArrays(
 292  *              array( array( 'x' ) ),
 293  *              array( array( 'x', '2' ) ),
 294  *              array( array( 'x' ) ),
 295  *              array( array( 'y' ) )
 296  *      );
 297  * returns:
 298  *              array(
 299  *              array( 'x', '2' ),
 300  *              array( 'x' ),
 301  *              array( 'y' )
 302  *      )
 303  *
 304  * @param array $array1,...
 305  * @return array
 306  */
 307 function wfMergeErrorArrays( /*...*/ ) {
 308         $args = func_get_args();
 309         $out = array();
 310         foreach ( $args as $errors ) {
 311                 foreach ( $errors as $params ) {
 312                         $originalParams = $params;
 313                         if ( $params[0] instanceof MessageSpecifier ) {
 314                                 $msg = $params[0];
 315                                 $params = array_merge( array( $msg->getKey() ), $msg->getParams() );
 316                         }
 317                         # @todo FIXME: Sometimes get nested arrays for $params,
 318                         # which leads to E_NOTICEs
 319                         $spec = implode( "\t", $params );
 320                         $out[$spec] = $originalParams;
 321                 }
 322         }
 323         return array_values( $out );
 324 }
 325
 326 /**
 327  * Insert array into another array after the specified *KEY*
 328  *
 329  * @param array $array The array.
 330  * @param array $insert The array to insert.
 331  * @param mixed $after The key to insert after
 332  * @return array
 333  */
 334 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 335         // Find the offset of the element to insert after.
 336         $keys = array_keys( $array );
 337         $offsetByKey = array_flip( $keys );
 338
 339         $offset = $offsetByKey[$after];
 340
 341         // Insert at the specified offset
 342         $before = array_slice( $array, 0, $offset + 1, true );
 343         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 344
 345         $output = $before + $insert + $after;
 346
 347         return $output;
 348 }
 349
 350 /**
 351  * Recursively converts the parameter (an object) to an array with the same data
 352  *
 353  * @param object|array $objOrArray
 354  * @param bool $recursive
 355  * @return array
 356  */
 357 function wfObjectToArray( $objOrArray, $recursive = true ) {
 358         $array = array();
 359         if ( is_object( $objOrArray ) ) {
 360                 $objOrArray = get_object_vars( $objOrArray );
 361         }
 362         foreach ( $objOrArray as $key => $value ) {
 363                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 364                         $value = wfObjectToArray( $value );
 365                 }
 366
 367                 $array[$key] = $value;
 368         }
 369
 370         return $array;
 371 }
 372
 373 /**
 374  * Get a random decimal value between 0 and 1, in a way
 375  * not likely to give duplicate values for any realistic
 376  * number of articles.
 377  *
 378  * @note This is designed for use in relation to Special:RandomPage
 379  *       and the page_random database field.
 380  *
 381  * @return string
 382  */
 383 function wfRandom() {
 384         // The maximum random value is "only" 2^31-1, so get two random
 385         // values to reduce the chance of dupes
 386         $max = mt_getrandmax() + 1;
 387         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 388         return $rand;
 389 }
 390
 391 /**
 392  * Get a random string containing a number of pseudo-random hex characters.
 393  *
 394  * @note This is not secure, if you are trying to generate some sort
 395  *       of token please use MWCryptRand instead.
 396  *
 397  * @param int $length The length of the string to generate
 398  * @return string
 399  * @since 1.20
 400  */
 401 function wfRandomString( $length = 32 ) {
 402         $str = '';
 403         for ( $n = 0; $n < $length; $n += 7 ) {
 404                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 405         }
 406         return substr( $str, 0, $length );
 407 }
 408
 409 /**
 410  * We want some things to be included as literal characters in our title URLs
 411  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 412  * all of the following should be safe:
 413  *
 414  * ;:@&=$-_.+!*'(),
 415  *
 416  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 417  * character which should not be encoded. More importantly, google chrome
 418  * always converts %7E back to ~, and converting it in this function can
 419  * cause a redirect loop (T105265).
 420  *
 421  * But + is not safe because it's used to indicate a space; &= are only safe in
 422  * paths and not in queries (and we don't distinguish here); ' seems kind of
 423  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 424  * is reserved, we don't care.  So the list we unescape is:
 425  *
 426  * ;:@$!*(),/~
 427  *
 428  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 429  * so no fancy : for IIS7.
 430  *
 431  * %2F in the page titles seems to fatally break for some reason.
 432  *
 433  * @param string $s
 434  * @return string
 435  */
 436 function wfUrlencode( $s ) {
 437         static $needle;
 438
 439         if ( is_null( $s ) ) {
 440                 $needle = null;
 441                 return '';
 442         }
 443
 444         if ( is_null( $needle ) ) {
 445                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' );
 446                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 447                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 448                 ) {
 449                         $needle[] = '%3A';
 450                 }
 451         }
 452
 453         $s = urlencode( $s );
 454         $s = str_ireplace(
 455                 $needle,
 456                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ),
 457                 $s
 458         );
 459
 460         return $s;
 461 }
 462
 463 /**
 464  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 465  * "days=7&limit=100". Options in the first array override options in the second.
 466  * Options set to null or false will not be output.
 467  *
 468  * @param array $array1 ( String|Array )
 469  * @param array|null $array2 ( String|Array )
 470  * @param string $prefix
 471  * @return string
 472  */
 473 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 474         if ( !is_null( $array2 ) ) {
 475                 $array1 = $array1 + $array2;
 476         }
 477
 478         $cgi = '';
 479         foreach ( $array1 as $key => $value ) {
 480                 if ( !is_null( $value ) && $value !== false ) {
 481                         if ( $cgi != '' ) {
 482                                 $cgi .= '&';
 483                         }
 484                         if ( $prefix !== '' ) {
 485                                 $key = $prefix . "[$key]";
 486                         }
 487                         if ( is_array( $value ) ) {
 488                                 $firstTime = true;
 489                                 foreach ( $value as $k => $v ) {
 490                                         $cgi .= $firstTime ? '' : '&';
 491                                         if ( is_array( $v ) ) {
 492                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 493                                         } else {
 494                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 495                                         }
 496                                         $firstTime = false;
 497                                 }
 498                         } else {
 499                                 if ( is_object( $value ) ) {
 500                                         $value = $value->__toString();
 501                                 }
 502                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 503                         }
 504                 }
 505         }
 506         return $cgi;
 507 }
 508
 509 /**
 510  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 511  * its argument and returns the same string in array form.  This allows compatibility
 512  * with legacy functions that accept raw query strings instead of nice
 513  * arrays.  Of course, keys and values are urldecode()d.
 514  *
 515  * @param string $query Query string
 516  * @return string[] Array version of input
 517  */
 518 function wfCgiToArray( $query ) {
 519         if ( isset( $query[0] ) && $query[0] == '?' ) {
 520                 $query = substr( $query, 1 );
 521         }
 522         $bits = explode( '&', $query );
 523         $ret = array();
 524         foreach ( $bits as $bit ) {
 525                 if ( $bit === '' ) {
 526                         continue;
 527                 }
 528                 if ( strpos( $bit, '=' ) === false ) {
 529                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 530                         $key = $bit;
 531                         $value = '';
 532                 } else {
 533                         list( $key, $value ) = explode( '=', $bit );
 534                 }
 535                 $key = urldecode( $key );
 536                 $value = urldecode( $value );
 537                 if ( strpos( $key, '[' ) !== false ) {
 538                         $keys = array_reverse( explode( '[', $key ) );
 539                         $key = array_pop( $keys );
 540                         $temp = $value;
 541                         foreach ( $keys as $k ) {
 542                                 $k = substr( $k, 0, -1 );
 543                                 $temp = array( $k => $temp );
 544                         }
 545                         if ( isset( $ret[$key] ) ) {
 546                                 $ret[$key] = array_merge( $ret[$key], $temp );
 547                         } else {
 548                                 $ret[$key] = $temp;
 549                         }
 550                 } else {
 551                         $ret[$key] = $value;
 552                 }
 553         }
 554         return $ret;
 555 }
 556
 557 /**
 558  * Append a query string to an existing URL, which may or may not already
 559  * have query string parameters already. If so, they will be combined.
 560  *
 561  * @param string $url
 562  * @param string|string[] $query String or associative array
 563  * @return string
 564  */
 565 function wfAppendQuery( $url, $query ) {
 566         if ( is_array( $query ) ) {
 567                 $query = wfArrayToCgi( $query );
 568         }
 569         if ( $query != '' ) {
 570                 if ( false === strpos( $url, '?' ) ) {
 571                         $url .= '?';
 572                 } else {
 573                         $url .= '&';
 574                 }
 575                 $url .= $query;
 576         }
 577         return $url;
 578 }
 579
 580 /**
 581  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 582  * is correct.
 583  *
 584  * The meaning of the PROTO_* constants is as follows:
 585  * PROTO_HTTP: Output a URL starting with http://
 586  * PROTO_HTTPS: Output a URL starting with https://
 587  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 588  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 589  *    on which protocol was used for the current incoming request
 590  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 591  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 592  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 593  *
 594  * @todo this won't work with current-path-relative URLs
 595  * like "subdir/foo.html", etc.
 596  *
 597  * @param string $url Either fully-qualified or a local path + query
 598  * @param string $defaultProto One of the PROTO_* constants. Determines the
 599  *    protocol to use if $url or $wgServer is protocol-relative
 600  * @return string Fully-qualified URL, current-path-relative URL or false if
 601  *    no valid URL can be constructed
 602  */
 603 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 604         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 605                 $wgHttpsPort;
 606         if ( $defaultProto === PROTO_CANONICAL ) {
 607                 $serverUrl = $wgCanonicalServer;
 608         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 609                 // Make $wgInternalServer fall back to $wgServer if not set
 610                 $serverUrl = $wgInternalServer;
 611         } else {
 612                 $serverUrl = $wgServer;
 613                 if ( $defaultProto === PROTO_CURRENT ) {
 614                         $defaultProto = $wgRequest->getProtocol() . '://';
 615                 }
 616         }
 617
 618         // Analyze $serverUrl to obtain its protocol
 619         $bits = wfParseUrl( $serverUrl );
 620         $serverHasProto = $bits && $bits['scheme'] != '';
 621
 622         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 623                 if ( $serverHasProto ) {
 624                         $defaultProto = $bits['scheme'] . '://';
 625                 } else {
 626                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 627                         // This really isn't supposed to happen. Fall back to HTTP in this
 628                         // ridiculous case.
 629                         $defaultProto = PROTO_HTTP;
 630                 }
 631         }
 632
 633         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 634
 635         if ( substr( $url, 0, 2 ) == '//' ) {
 636                 $url = $defaultProtoWithoutSlashes . $url;
 637         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 638                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 639                 // otherwise leave it alone.
 640                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 641         }
 642
 643         $bits = wfParseUrl( $url );
 644
 645         // ensure proper port for HTTPS arrives in URL
 646         // https://phabricator.wikimedia.org/T67184
 647         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 648                 $bits['port'] = $wgHttpsPort;
 649         }
 650
 651         if ( $bits && isset( $bits['path'] ) ) {
 652                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 653                 return wfAssembleUrl( $bits );
 654         } elseif ( $bits ) {
 655                 # No path to expand
 656                 return $url;
 657         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 658                 # URL is a relative path
 659                 return wfRemoveDotSegments( $url );
 660         }
 661
 662         # Expanded URL is not valid.
 663         return false;
 664 }
 665
 666 /**
 667  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 668  * if you need to edit part of a URL and put it back together.
 669  *
 670  * This is the basic structure used (brackets contain keys for $urlParts):
 671  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 672  *
 673  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 674  *
 675  * @since 1.19
 676  * @param array $urlParts URL parts, as output from wfParseUrl
 677  * @return string URL assembled from its component parts
 678  */
 679 function wfAssembleUrl( $urlParts ) {
 680         $result = '';
 681
 682         if ( isset( $urlParts['delimiter'] ) ) {
 683                 if ( isset( $urlParts['scheme'] ) ) {
 684                         $result .= $urlParts['scheme'];
 685                 }
 686
 687                 $result .= $urlParts['delimiter'];
 688         }
 689
 690         if ( isset( $urlParts['host'] ) ) {
 691                 if ( isset( $urlParts['user'] ) ) {
 692                         $result .= $urlParts['user'];
 693                         if ( isset( $urlParts['pass'] ) ) {
 694                                 $result .= ':' . $urlParts['pass'];
 695                         }
 696                         $result .= '@';
 697                 }
 698
 699                 $result .= $urlParts['host'];
 700
 701                 if ( isset( $urlParts['port'] ) ) {
 702                         $result .= ':' . $urlParts['port'];
 703                 }
 704         }
 705
 706         if ( isset( $urlParts['path'] ) ) {
 707                 $result .= $urlParts['path'];
 708         }
 709
 710         if ( isset( $urlParts['query'] ) ) {
 711                 $result .= '?' . $urlParts['query'];
 712         }
 713
 714         if ( isset( $urlParts['fragment'] ) ) {
 715                 $result .= '#' . $urlParts['fragment'];
 716         }
 717
 718         return $result;
 719 }
 720
 721 /**
 722  * Remove all dot-segments in the provided URL path.  For example,
 723  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 724  * RFC3986 section 5.2.4.
 725  *
 726  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 727  *
 728  * @param string $urlPath URL path, potentially containing dot-segments
 729  * @return string URL path with all dot-segments removed
 730  */
 731 function wfRemoveDotSegments( $urlPath ) {
 732         $output = '';
 733         $inputOffset = 0;
 734         $inputLength = strlen( $urlPath );
 735
 736         while ( $inputOffset < $inputLength ) {
 737                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 738                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 739                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 740                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 741                 $trimOutput = false;
 742
 743                 if ( $prefixLengthTwo == './' ) {
 744                         # Step A, remove leading "./"
 745                         $inputOffset += 2;
 746                 } elseif ( $prefixLengthThree == '../' ) {
 747                         # Step A, remove leading "../"
 748                         $inputOffset += 3;
 749                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 750                         # Step B, replace leading "/.$" with "/"
 751                         $inputOffset += 1;
 752                         $urlPath[$inputOffset] = '/';
 753                 } elseif ( $prefixLengthThree == '/./' ) {
 754                         # Step B, replace leading "/./" with "/"
 755                         $inputOffset += 2;
 756                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 757                         # Step C, replace leading "/..$" with "/" and
 758                         # remove last path component in output
 759                         $inputOffset += 2;
 760                         $urlPath[$inputOffset] = '/';
 761                         $trimOutput = true;
 762                 } elseif ( $prefixLengthFour == '/../' ) {
 763                         # Step C, replace leading "/../" with "/" and
 764                         # remove last path component in output
 765                         $inputOffset += 3;
 766                         $trimOutput = true;
 767                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 768                         # Step D, remove "^.$"
 769                         $inputOffset += 1;
 770                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 771                         # Step D, remove "^..$"
 772                         $inputOffset += 2;
 773                 } else {
 774                         # Step E, move leading path segment to output
 775                         if ( $prefixLengthOne == '/' ) {
 776                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 777                         } else {
 778                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 779                         }
 780                         if ( $slashPos === false ) {
 781                                 $output .= substr( $urlPath, $inputOffset );
 782                                 $inputOffset = $inputLength;
 783                         } else {
 784                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 785                                 $inputOffset += $slashPos - $inputOffset;
 786                         }
 787                 }
 788
 789                 if ( $trimOutput ) {
 790                         $slashPos = strrpos( $output, '/' );
 791                         if ( $slashPos === false ) {
 792                                 $output = '';
 793                         } else {
 794                                 $output = substr( $output, 0, $slashPos );
 795                         }
 796                 }
 797         }
 798
 799         return $output;
 800 }
 801
 802 /**
 803  * Returns a regular expression of url protocols
 804  *
 805  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 806  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 807  * @return string
 808  */
 809 function wfUrlProtocols( $includeProtocolRelative = true ) {
 810         global $wgUrlProtocols;
 811
 812         // Cache return values separately based on $includeProtocolRelative
 813         static $withProtRel = null, $withoutProtRel = null;
 814         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 815         if ( !is_null( $cachedValue ) ) {
 816                 return $cachedValue;
 817         }
 818
 819         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 820         // with LocalSettings files from 1.5
 821         if ( is_array( $wgUrlProtocols ) ) {
 822                 $protocols = array();
 823                 foreach ( $wgUrlProtocols as $protocol ) {
 824                         // Filter out '//' if !$includeProtocolRelative
 825                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 826                                 $protocols[] = preg_quote( $protocol, '/' );
 827                         }
 828                 }
 829
 830                 $retval = implode( '|', $protocols );
 831         } else {
 832                 // Ignore $includeProtocolRelative in this case
 833                 // This case exists for pre-1.6 compatibility, and we can safely assume
 834                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 835                 // URLs weren't supported until 1.18
 836                 $retval = $wgUrlProtocols;
 837         }
 838
 839         // Cache return value
 840         if ( $includeProtocolRelative ) {
 841                 $withProtRel = $retval;
 842         } else {
 843                 $withoutProtRel = $retval;
 844         }
 845         return $retval;
 846 }
 847
 848 /**
 849  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 850  * you need a regex that matches all URL protocols but does not match protocol-
 851  * relative URLs
 852  * @return string
 853  */
 854 function wfUrlProtocolsWithoutProtRel() {
 855         return wfUrlProtocols( false );
 856 }
 857
 858 /**
 859  * parse_url() work-alike, but non-broken.  Differences:
 860  *
 861  * 1) Does not raise warnings on bad URLs (just returns false).
 862  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 863  *    protocol-relative URLs) correctly.
 864  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 865  *
 866  * @param string $url A URL to parse
 867  * @return string[] Bits of the URL in an associative array, per PHP docs
 868  */
 869 function wfParseUrl( $url ) {
 870         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 871
 872         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 873         // bad that the easiest way to handle them is to just prepend 'http:' and
 874         // strip the protocol out later.
 875         $wasRelative = substr( $url, 0, 2 ) == '//';
 876         if ( $wasRelative ) {
 877                 $url = "http:$url";
 878         }
 879         MediaWiki\suppressWarnings();
 880         $bits = parse_url( $url );
 881         MediaWiki\restoreWarnings();
 882         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 883         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 884         if ( !$bits || !isset( $bits['scheme'] ) ) {
 885                 return false;
 886         }
 887
 888         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 889         $bits['scheme'] = strtolower( $bits['scheme'] );
 890
 891         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 892         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 893                 $bits['delimiter'] = '://';
 894         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 895                 $bits['delimiter'] = ':';
 896                 // parse_url detects for news: and mailto: the host part of an url as path
 897                 // We have to correct this wrong detection
 898                 if ( isset( $bits['path'] ) ) {
 899                         $bits['host'] = $bits['path'];
 900                         $bits['path'] = '';
 901                 }
 902         } else {
 903                 return false;
 904         }
 905
 906         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 907         if ( !isset( $bits['host'] ) ) {
 908                 $bits['host'] = '';
 909
 910                 // bug 45069
 911                 if ( isset( $bits['path'] ) ) {
 912                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 913                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 914                                 $bits['path'] = '/' . $bits['path'];
 915                         }
 916                 } else {
 917                         $bits['path'] = '';
 918                 }
 919         }
 920
 921         // If the URL was protocol-relative, fix scheme and delimiter
 922         if ( $wasRelative ) {
 923                 $bits['scheme'] = '';
 924                 $bits['delimiter'] = '//';
 925         }
 926         return $bits;
 927 }
 928
 929 /**
 930  * Take a URL, make sure it's expanded to fully qualified, and replace any
 931  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 932  * for more compact display and legibility for local audiences.
 933  *
 934  * @todo handle punycode domains too
 935  *
 936  * @param string $url
 937  * @return string
 938  */
 939 function wfExpandIRI( $url ) {
 940         return preg_replace_callback(
 941                 '/((?:%[89A-F][0-9A-F])+)/i',
 942                 'wfExpandIRI_callback',
 943                 wfExpandUrl( $url )
 944         );
 945 }
 946
 947 /**
 948  * Private callback for wfExpandIRI
 949  * @param array $matches
 950  * @return string
 951  */
 952 function wfExpandIRI_callback( $matches ) {
 953         return urldecode( $matches[1] );
 954 }
 955
 956 /**
 957  * Make URL indexes, appropriate for the el_index field of externallinks.
 958  *
 959  * @param string $url
 960  * @return array
 961  */
 962 function wfMakeUrlIndexes( $url ) {
 963         $bits = wfParseUrl( $url );
 964
 965         // Reverse the labels in the hostname, convert to lower case
 966         // For emails reverse domainpart only
 967         if ( $bits['scheme'] == 'mailto' ) {
 968                 $mailparts = explode( '@', $bits['host'], 2 );
 969                 if ( count( $mailparts ) === 2 ) {
 970                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 971                 } else {
 972                         // No domain specified, don't mangle it
 973                         $domainpart = '';
 974                 }
 975                 $reversedHost = $domainpart . '@' . $mailparts[0];
 976         } else {
 977                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 978         }
 979         // Add an extra dot to the end
 980         // Why? Is it in wrong place in mailto links?
 981         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 982                 $reversedHost .= '.';
 983         }
 984         // Reconstruct the pseudo-URL
 985         $prot = $bits['scheme'];
 986         $index = $prot . $bits['delimiter'] . $reversedHost;
 987         // Leave out user and password. Add the port, path, query and fragment
 988         if ( isset( $bits['port'] ) ) {
 989                 $index .= ':' . $bits['port'];
 990         }
 991         if ( isset( $bits['path'] ) ) {
 992                 $index .= $bits['path'];
 993         } else {
 994                 $index .= '/';
 995         }
 996         if ( isset( $bits['query'] ) ) {
 997                 $index .= '?' . $bits['query'];
 998         }
 999         if ( isset( $bits['fragment'] ) ) {
1000                 $index .= '#' . $bits['fragment'];
1001         }
1002
1003         if ( $prot == '' ) {
1004                 return array( "http:$index", "https:$index" );
1005         } else {
1006                 return array( $index );
1007         }
1008 }
1009
1010 /**
1011  * Check whether a given URL has a domain that occurs in a given set of domains
1012  * @param string $url URL
1013  * @param array $domains Array of domains (strings)
1014  * @return bool True if the host part of $url ends in one of the strings in $domains
1015  */
1016 function wfMatchesDomainList( $url, $domains ) {
1017         $bits = wfParseUrl( $url );
1018         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1019                 $host = '.' . $bits['host'];
1020                 foreach ( (array)$domains as $domain ) {
1021                         $domain = '.' . $domain;
1022                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1023                                 return true;
1024                         }
1025                 }
1026         }
1027         return false;
1028 }
1029
1030 /**
1031  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1032  * In normal operation this is a NOP.
1033  *
1034  * Controlling globals:
1035  * $wgDebugLogFile - points to the log file
1036  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1037  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1038  *
1039  * @since 1.25 support for additional context data
1040  *
1041  * @param string $text
1042  * @param string|bool $dest Destination of the message:
1043  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1044  *     - 'private': excluded from HTML output
1045  *   For backward compatibility, it can also take a boolean:
1046  *     - true: same as 'all'
1047  *     - false: same as 'private'
1048  * @param array $context Additional logging context data
1049  */
1050 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1051         global $wgDebugRawPage, $wgDebugLogPrefix;
1052         global $wgDebugTimestamps, $wgRequestTime;
1053
1054         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1055                 return;
1056         }
1057
1058         $text = trim( $text );
1059
1060         if ( $wgDebugTimestamps ) {
1061                 $context['seconds_elapsed'] = sprintf(
1062                         '%6.4f',
1063                         microtime( true ) - $wgRequestTime
1064                 );
1065                 $context['memory_used'] = sprintf(
1066                         '%5.1fM',
1067                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1068                 );
1069         }
1070
1071         if ( $wgDebugLogPrefix !== '' ) {
1072                 $context['prefix'] = $wgDebugLogPrefix;
1073         }
1074         $context['private'] = ( $dest === false || $dest === 'private' );
1075
1076         $logger = LoggerFactory::getInstance( 'wfDebug' );
1077         $logger->debug( $text, $context );
1078 }
1079
1080 /**
1081  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1082  * @return bool
1083  */
1084 function wfIsDebugRawPage() {
1085         static $cache;
1086         if ( $cache !== null ) {
1087                 return $cache;
1088         }
1089         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1090         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1091                 || (
1092                         isset( $_SERVER['SCRIPT_NAME'] )
1093                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1094                 )
1095         ) {
1096                 $cache = true;
1097         } else {
1098                 $cache = false;
1099         }
1100         return $cache;
1101 }
1102
1103 /**
1104  * Send a line giving PHP memory usage.
1105  *
1106  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1107  */
1108 function wfDebugMem( $exact = false ) {
1109         $mem = memory_get_usage();
1110         if ( !$exact ) {
1111                 $mem = floor( $mem / 1024 ) . ' KiB';
1112         } else {
1113                 $mem .= ' B';
1114         }
1115         wfDebug( "Memory usage: $mem\n" );
1116 }
1117
1118 /**
1119  * Send a line to a supplementary debug log file, if configured, or main debug
1120  * log if not.
1121  *
1122  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1123  * a string filename or an associative array mapping 'destination' to the
1124  * desired filename. The associative array may also contain a 'sample' key
1125  * with an integer value, specifying a sampling factor. Sampled log events
1126  * will be emitted with a 1 in N random chance.
1127  *
1128  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1129  * @since 1.25 support for additional context data
1130  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1131  *
1132  * @param string $logGroup
1133  * @param string $text
1134  * @param string|bool $dest Destination of the message:
1135  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1136  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1137  *       discarded otherwise
1138  *   For backward compatibility, it can also take a boolean:
1139  *     - true: same as 'all'
1140  *     - false: same as 'private'
1141  * @param array $context Additional logging context data
1142  */
1143 function wfDebugLog(
1144         $logGroup, $text, $dest = 'all', array $context = array()
1145 ) {
1146         $text = trim( $text );
1147
1148         $logger = LoggerFactory::getInstance( $logGroup );
1149         $context['private'] = ( $dest === false || $dest === 'private' );
1150         $logger->info( $text, $context );
1151 }
1152
1153 /**
1154  * Log for database errors
1155  *
1156  * @since 1.25 support for additional context data
1157  *
1158  * @param string $text Database error message.
1159  * @param array $context Additional logging context data
1160  */
1161 function wfLogDBError( $text, array $context = array() ) {
1162         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1163         $logger->error( trim( $text ), $context );
1164 }
1165
1166 /**
1167  * Throws a warning that $function is deprecated
1168  *
1169  * @param string $function
1170  * @param string|bool $version Version of MediaWiki that the function
1171  *    was deprecated in (Added in 1.19).
1172  * @param string|bool $component Added in 1.19.
1173  * @param int $callerOffset How far up the call stack is the original
1174  *    caller. 2 = function that called the function that called
1175  *    wfDeprecated (Added in 1.20)
1176  *
1177  * @return null
1178  */
1179 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1180         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1181 }
1182
1183 /**
1184  * Send a warning either to the debug log or in a PHP error depending on
1185  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1186  *
1187  * @param string $msg Message to send
1188  * @param int $callerOffset Number of items to go back in the backtrace to
1189  *        find the correct caller (1 = function calling wfWarn, ...)
1190  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1191  *        only used when $wgDevelopmentWarnings is true
1192  */
1193 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1194         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1195 }
1196
1197 /**
1198  * Send a warning as a PHP error and the debug log. This is intended for logging
1199  * warnings in production. For logging development warnings, use WfWarn instead.
1200  *
1201  * @param string $msg Message to send
1202  * @param int $callerOffset Number of items to go back in the backtrace to
1203  *        find the correct caller (1 = function calling wfLogWarning, ...)
1204  * @param int $level PHP error level; defaults to E_USER_WARNING
1205  */
1206 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1207         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1208 }
1209
1210 /**
1211  * Log to a file without getting "file size exceeded" signals.
1212  *
1213  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1214  * send lines to the specified port, prefixed by the specified prefix and a space.
1215  * @since 1.25 support for additional context data
1216  *
1217  * @param string $text
1218  * @param string $file Filename
1219  * @param array $context Additional logging context data
1220  * @throws MWException
1221  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1222  */
1223 function wfErrorLog( $text, $file, array $context = array() ) {
1224         wfDeprecated( __METHOD__, '1.25' );
1225         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1226         $context['destination'] = $file;
1227         $logger->info( trim( $text ), $context );
1228 }
1229
1230 /**
1231  * @todo document
1232  */
1233 function wfLogProfilingData() {
1234         global $wgDebugLogGroups, $wgDebugRawPage;
1235
1236         $context = RequestContext::getMain();
1237         $request = $context->getRequest();
1238
1239         $profiler = Profiler::instance();
1240         $profiler->setContext( $context );
1241         $profiler->logData();
1242
1243         $config = $context->getConfig();
1244         if ( $config->get( 'StatsdServer' ) ) {
1245                 try {
1246                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1247                         $statsdHost = $statsdServer[0];
1248                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1249                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1250                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1251                         $statsdClient->send( $context->getStats()->getBuffer() );
1252                 } catch ( Exception $ex ) {
1253                         MWExceptionHandler::logException( $ex );
1254                 }
1255         }
1256
1257         # Profiling must actually be enabled...
1258         if ( $profiler instanceof ProfilerStub ) {
1259                 return;
1260         }
1261
1262         if ( isset( $wgDebugLogGroups['profileoutput'] )
1263                 && $wgDebugLogGroups['profileoutput'] === false
1264         ) {
1265                 // Explicitly disabled
1266                 return;
1267         }
1268         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1269                 return;
1270         }
1271
1272         $ctx = array( 'elapsed' => $request->getElapsedTime() );
1273         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1274                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1275         }
1276         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1277                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1278         }
1279         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1280                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1281         }
1282         if ( isset( $ctx['forwarded_for'] ) ||
1283                 isset( $ctx['client_ip'] ) ||
1284                 isset( $ctx['from'] ) ) {
1285                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1286         }
1287
1288         // Don't load $wgUser at this late stage just for statistics purposes
1289         // @todo FIXME: We can detect some anons even if it is not loaded.
1290         // See User::getId()
1291         $user = $context->getUser();
1292         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1293
1294         // Command line script uses a FauxRequest object which does not have
1295         // any knowledge about an URL and throw an exception instead.
1296         try {
1297                 $ctx['url'] = urldecode( $request->getRequestURL() );
1298         } catch ( Exception $ignored ) {
1299                 // no-op
1300         }
1301
1302         $ctx['output'] = $profiler->getOutput();
1303
1304         $log = LoggerFactory::getInstance( 'profileoutput' );
1305         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1306 }
1307
1308 /**
1309  * Increment a statistics counter
1310  *
1311  * @param string $key
1312  * @param int $count
1313  * @return void
1314  */
1315 function wfIncrStats( $key, $count = 1 ) {
1316         $stats = RequestContext::getMain()->getStats();
1317         $stats->updateCount( $key, $count );
1318 }
1319
1320 /**
1321  * Check whether the wiki is in read-only mode.
1322  *
1323  * @return bool
1324  */
1325 function wfReadOnly() {
1326         return wfReadOnlyReason() !== false;
1327 }
1328
1329 /**
1330  * Check if the site is in read-only mode and return the message if so
1331  *
1332  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1333  * for slave lag. This may result in DB_SLAVE connection being made.
1334  *
1335  * @return string|bool String when in read-only mode; false otherwise
1336  */
1337 function wfReadOnlyReason() {
1338         $readOnly = wfConfiguredReadOnlyReason();
1339         if ( $readOnly !== false ) {
1340                 return $readOnly;
1341         }
1342
1343         static $lbReadOnly = null;
1344         if ( $lbReadOnly === null ) {
1345                 // Callers use this method to be aware that data presented to a user
1346                 // may be very stale and thus allowing submissions can be problematic.
1347                 $lbReadOnly = wfGetLB()->getReadOnlyReason();
1348         }
1349
1350         return $lbReadOnly;
1351 }
1352
1353 /**
1354  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1355  *
1356  * @return string|bool String when in read-only mode; false otherwise
1357  * @since 1.27
1358  */
1359 function wfConfiguredReadOnlyReason() {
1360         global $wgReadOnly, $wgReadOnlyFile;
1361
1362         if ( $wgReadOnly === null ) {
1363                 // Set $wgReadOnly for faster access next time
1364                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1365                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1366                 } else {
1367                         $wgReadOnly = false;
1368                 }
1369         }
1370
1371         return $wgReadOnly;
1372 }
1373
1374 /**
1375  * Return a Language object from $langcode
1376  *
1377  * @param Language|string|bool $langcode Either:
1378  *                  - a Language object
1379  *                  - code of the language to get the message for, if it is
1380  *                    a valid code create a language for that language, if
1381  *                    it is a string but not a valid code then make a basic
1382  *                    language object
1383  *                  - a boolean: if it's false then use the global object for
1384  *                    the current user's language (as a fallback for the old parameter
1385  *                    functionality), or if it is true then use global object
1386  *                    for the wiki's content language.
1387  * @return Language
1388  */
1389 function wfGetLangObj( $langcode = false ) {
1390         # Identify which language to get or create a language object for.
1391         # Using is_object here due to Stub objects.
1392         if ( is_object( $langcode ) ) {
1393                 # Great, we already have the object (hopefully)!
1394                 return $langcode;
1395         }
1396
1397         global $wgContLang, $wgLanguageCode;
1398         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1399                 # $langcode is the language code of the wikis content language object.
1400                 # or it is a boolean and value is true
1401                 return $wgContLang;
1402         }
1403
1404         global $wgLang;
1405         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1406                 # $langcode is the language code of user language object.
1407                 # or it was a boolean and value is false
1408                 return $wgLang;
1409         }
1410
1411         $validCodes = array_keys( Language::fetchLanguageNames() );
1412         if ( in_array( $langcode, $validCodes ) ) {
1413                 # $langcode corresponds to a valid language.
1414                 return Language::factory( $langcode );
1415         }
1416
1417         # $langcode is a string, but not a valid language code; use content language.
1418         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1419         return $wgContLang;
1420 }
1421
1422 /**
1423  * This is the function for getting translated interface messages.
1424  *
1425  * @see Message class for documentation how to use them.
1426  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1427  *
1428  * This function replaces all old wfMsg* functions.
1429  *
1430  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1431  * @param mixed $params,... Normal message parameters
1432  * @return Message
1433  *
1434  * @since 1.17
1435  *
1436  * @see Message::__construct
1437  */
1438 function wfMessage( $key /*...*/ ) {
1439         $params = func_get_args();
1440         array_shift( $params );
1441         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1442                 $params = $params[0];
1443         }
1444         return new Message( $key, $params );
1445 }
1446
1447 /**
1448  * This function accepts multiple message keys and returns a message instance
1449  * for the first message which is non-empty. If all messages are empty then an
1450  * instance of the first message key is returned.
1451  *
1452  * @param string|string[] $keys,... Message keys
1453  * @return Message
1454  *
1455  * @since 1.18
1456  *
1457  * @see Message::newFallbackSequence
1458  */
1459 function wfMessageFallback( /*...*/ ) {
1460         $args = func_get_args();
1461         return call_user_func_array( 'Message::newFallbackSequence', $args );
1462 }
1463
1464 /**
1465  * Replace message parameter keys on the given formatted output.
1466  *
1467  * @param string $message
1468  * @param array $args
1469  * @return string
1470  * @private
1471  */
1472 function wfMsgReplaceArgs( $message, $args ) {
1473         # Fix windows line-endings
1474         # Some messages are split with explode("\n", $msg)
1475         $message = str_replace( "\r", '', $message );
1476
1477         // Replace arguments
1478         if ( count( $args ) ) {
1479                 if ( is_array( $args[0] ) ) {
1480                         $args = array_values( $args[0] );
1481                 }
1482                 $replacementKeys = array();
1483                 foreach ( $args as $n => $param ) {
1484                         $replacementKeys['$' . ( $n + 1 )] = $param;
1485                 }
1486                 $message = strtr( $message, $replacementKeys );
1487         }
1488
1489         return $message;
1490 }
1491
1492 /**
1493  * Fetch server name for use in error reporting etc.
1494  * Use real server name if available, so we know which machine
1495  * in a server farm generated the current page.
1496  *
1497  * @return string
1498  */
1499 function wfHostname() {
1500         static $host;
1501         if ( is_null( $host ) ) {
1502
1503                 # Hostname overriding
1504                 global $wgOverrideHostname;
1505                 if ( $wgOverrideHostname !== false ) {
1506                         # Set static and skip any detection
1507                         $host = $wgOverrideHostname;
1508                         return $host;
1509                 }
1510
1511                 if ( function_exists( 'posix_uname' ) ) {
1512                         // This function not present on Windows
1513                         $uname = posix_uname();
1514                 } else {
1515                         $uname = false;
1516                 }
1517                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1518                         $host = $uname['nodename'];
1519                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1520                         # Windows computer name
1521                         $host = getenv( 'COMPUTERNAME' );
1522                 } else {
1523                         # This may be a virtual server.
1524                         $host = $_SERVER['SERVER_NAME'];
1525                 }
1526         }
1527         return $host;
1528 }
1529
1530 /**
1531  * Returns a script tag that stores the amount of time it took MediaWiki to
1532  * handle the request in milliseconds as 'wgBackendResponseTime'.
1533  *
1534  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1535  * hostname of the server handling the request.
1536  *
1537  * @return string
1538  */
1539 function wfReportTime() {
1540         global $wgRequestTime, $wgShowHostnames;
1541
1542         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1543         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1544         if ( $wgShowHostnames ) {
1545                 $reportVars['wgHostname'] = wfHostname();
1546         }
1547         return Skin::makeVariablesScript( $reportVars );
1548 }
1549
1550 /**
1551  * Safety wrapper for debug_backtrace().
1552  *
1553  * Will return an empty array if debug_backtrace is disabled, otherwise
1554  * the output from debug_backtrace() (trimmed).
1555  *
1556  * @param int $limit This parameter can be used to limit the number of stack frames returned
1557  *
1558  * @return array Array of backtrace information
1559  */
1560 function wfDebugBacktrace( $limit = 0 ) {
1561         static $disabled = null;
1562
1563         if ( is_null( $disabled ) ) {
1564                 $disabled = !function_exists( 'debug_backtrace' );
1565                 if ( $disabled ) {
1566                         wfDebug( "debug_backtrace() is disabled\n" );
1567                 }
1568         }
1569         if ( $disabled ) {
1570                 return array();
1571         }
1572
1573         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1574                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1575         } else {
1576                 return array_slice( debug_backtrace(), 1 );
1577         }
1578 }
1579
1580 /**
1581  * Get a debug backtrace as a string
1582  *
1583  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1584  *   Defaults to $wgCommandLineMode if unset.
1585  * @return string
1586  * @since 1.25 Supports $raw parameter.
1587  */
1588 function wfBacktrace( $raw = null ) {
1589         global $wgCommandLineMode;
1590
1591         if ( $raw === null ) {
1592                 $raw = $wgCommandLineMode;
1593         }
1594
1595         if ( $raw ) {
1596                 $frameFormat = "%s line %s calls %s()\n";
1597                 $traceFormat = "%s";
1598         } else {
1599                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1600                 $traceFormat = "<ul>\n%s</ul>\n";
1601         }
1602
1603         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1604                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1605                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1606                 $call = $frame['function'];
1607                 if ( !empty( $frame['class'] ) ) {
1608                         $call = $frame['class'] . $frame['type'] . $call;
1609                 }
1610                 return sprintf( $frameFormat, $file, $line, $call );
1611         }, wfDebugBacktrace() );
1612
1613         return sprintf( $traceFormat, implode( '', $frames ) );
1614 }
1615
1616 /**
1617  * Get the name of the function which called this function
1618  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1619  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1620  * wfGetCaller( 3 ) is the parent of that.
1621  *
1622  * @param int $level
1623  * @return string
1624  */
1625 function wfGetCaller( $level = 2 ) {
1626         $backtrace = wfDebugBacktrace( $level + 1 );
1627         if ( isset( $backtrace[$level] ) ) {
1628                 return wfFormatStackFrame( $backtrace[$level] );
1629         } else {
1630                 return 'unknown';
1631         }
1632 }
1633
1634 /**
1635  * Return a string consisting of callers in the stack. Useful sometimes
1636  * for profiling specific points.
1637  *
1638  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1639  * @return string
1640  */
1641 function wfGetAllCallers( $limit = 3 ) {
1642         $trace = array_reverse( wfDebugBacktrace() );
1643         if ( !$limit || $limit > count( $trace ) - 1 ) {
1644                 $limit = count( $trace ) - 1;
1645         }
1646         $trace = array_slice( $trace, -$limit - 1, $limit );
1647         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1648 }
1649
1650 /**
1651  * Return a string representation of frame
1652  *
1653  * @param array $frame
1654  * @return string
1655  */
1656 function wfFormatStackFrame( $frame ) {
1657         if ( !isset( $frame['function'] ) ) {
1658                 return 'NO_FUNCTION_GIVEN';
1659         }
1660         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1661                 $frame['class'] . $frame['type'] . $frame['function'] :
1662                 $frame['function'];
1663 }
1664
1665 /* Some generic result counters, pulled out of SearchEngine */
1666
1667 /**
1668  * @todo document
1669  *
1670  * @param int $offset
1671  * @param int $limit
1672  * @return string
1673  */
1674 function wfShowingResults( $offset, $limit ) {
1675         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1676 }
1677
1678 /**
1679  * @todo document
1680  * @todo FIXME: We may want to blacklist some broken browsers
1681  *
1682  * @param bool $force
1683  * @return bool Whereas client accept gzip compression
1684  */
1685 function wfClientAcceptsGzip( $force = false ) {
1686         static $result = null;
1687         if ( $result === null || $force ) {
1688                 $result = false;
1689                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1690                         # @todo FIXME: We may want to blacklist some broken browsers
1691                         $m = array();
1692                         if ( preg_match(
1693                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1694                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1695                                         $m
1696                                 )
1697                         ) {
1698                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1699                                         $result = false;
1700                                         return $result;
1701                                 }
1702                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1703                                 $result = true;
1704                         }
1705                 }
1706         }
1707         return $result;
1708 }
1709
1710 /**
1711  * Escapes the given text so that it may be output using addWikiText()
1712  * without any linking, formatting, etc. making its way through. This
1713  * is achieved by substituting certain characters with HTML entities.
1714  * As required by the callers, "<nowiki>" is not used.
1715  *
1716  * @param string $text Text to be escaped
1717  * @return string
1718  */
1719 function wfEscapeWikiText( $text ) {
1720         static $repl = null, $repl2 = null;
1721         if ( $repl === null ) {
1722                 $repl = array(
1723                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1724                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1725                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1726                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1727                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1728                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1729                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1730                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1731                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1732                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1733                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1734                         '__' => '_&#95;', '://' => '&#58;//',
1735                 );
1736
1737                 // We have to catch everything "\s" matches in PCRE
1738                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
1739                         $repl["$magic "] = "$magic&#32;";
1740                         $repl["$magic\t"] = "$magic&#9;";
1741                         $repl["$magic\r"] = "$magic&#13;";
1742                         $repl["$magic\n"] = "$magic&#10;";
1743                         $repl["$magic\f"] = "$magic&#12;";
1744                 }
1745
1746                 // And handle protocols that don't use "://"
1747                 global $wgUrlProtocols;
1748                 $repl2 = array();
1749                 foreach ( $wgUrlProtocols as $prot ) {
1750                         if ( substr( $prot, -1 ) === ':' ) {
1751                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1752                         }
1753                 }
1754                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
1755         }
1756         $text = substr( strtr( "\n$text", $repl ), 1 );
1757         $text = preg_replace( $repl2, '$1&#58;', $text );
1758         return $text;
1759 }
1760
1761 /**
1762  * Sets dest to source and returns the original value of dest
1763  * If source is NULL, it just returns the value, it doesn't set the variable
1764  * If force is true, it will set the value even if source is NULL
1765  *
1766  * @param mixed $dest
1767  * @param mixed $source
1768  * @param bool $force
1769  * @return mixed
1770  */
1771 function wfSetVar( &$dest, $source, $force = false ) {
1772         $temp = $dest;
1773         if ( !is_null( $source ) || $force ) {
1774                 $dest = $source;
1775         }
1776         return $temp;
1777 }
1778
1779 /**
1780  * As for wfSetVar except setting a bit
1781  *
1782  * @param int $dest
1783  * @param int $bit
1784  * @param bool $state
1785  *
1786  * @return bool
1787  */
1788 function wfSetBit( &$dest, $bit, $state = true ) {
1789         $temp = (bool)( $dest & $bit );
1790         if ( !is_null( $state ) ) {
1791                 if ( $state ) {
1792                         $dest |= $bit;
1793                 } else {
1794                         $dest &= ~$bit;
1795                 }
1796         }
1797         return $temp;
1798 }
1799
1800 /**
1801  * A wrapper around the PHP function var_export().
1802  * Either print it or add it to the regular output ($wgOut).
1803  *
1804  * @param mixed $var A PHP variable to dump.
1805  */
1806 function wfVarDump( $var ) {
1807         global $wgOut;
1808         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1809         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1810                 print $s;
1811         } else {
1812                 $wgOut->addHTML( $s );
1813         }
1814 }
1815
1816 /**
1817  * Provide a simple HTTP error.
1818  *
1819  * @param int|string $code
1820  * @param string $label
1821  * @param string $desc
1822  */
1823 function wfHttpError( $code, $label, $desc ) {
1824         global $wgOut;
1825         HttpStatus::header( $code );
1826         if ( $wgOut ) {
1827                 $wgOut->disable();
1828                 $wgOut->sendCacheControl();
1829         }
1830
1831         header( 'Content-type: text/html; charset=utf-8' );
1832         print '<!DOCTYPE html>' .
1833                 '<html><head><title>' .
1834                 htmlspecialchars( $label ) .
1835                 '</title></head><body><h1>' .
1836                 htmlspecialchars( $label ) .
1837                 '</h1><p>' .
1838                 nl2br( htmlspecialchars( $desc ) ) .
1839                 "</p></body></html>\n";
1840 }
1841
1842 /**
1843  * Clear away any user-level output buffers, discarding contents.
1844  *
1845  * Suitable for 'starting afresh', for instance when streaming
1846  * relatively large amounts of data without buffering, or wanting to
1847  * output image files without ob_gzhandler's compression.
1848  *
1849  * The optional $resetGzipEncoding parameter controls suppression of
1850  * the Content-Encoding header sent by ob_gzhandler; by default it
1851  * is left. See comments for wfClearOutputBuffers() for why it would
1852  * be used.
1853  *
1854  * Note that some PHP configuration options may add output buffer
1855  * layers which cannot be removed; these are left in place.
1856  *
1857  * @param bool $resetGzipEncoding
1858  */
1859 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1860         if ( $resetGzipEncoding ) {
1861                 // Suppress Content-Encoding and Content-Length
1862                 // headers from 1.10+s wfOutputHandler
1863                 global $wgDisableOutputCompression;
1864                 $wgDisableOutputCompression = true;
1865         }
1866         while ( $status = ob_get_status() ) {
1867                 if ( isset( $status['flags'] ) ) {
1868                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1869                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1870                 } elseif ( isset( $status['del'] ) ) {
1871                         $deleteable = $status['del'];
1872                 } else {
1873                         // Guess that any PHP-internal setting can't be removed.
1874                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1875                 }
1876                 if ( !$deleteable ) {
1877                         // Give up, and hope the result doesn't break
1878                         // output behavior.
1879                         break;
1880                 }
1881                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1882                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1883                         break;
1884                 }
1885                 if ( !ob_end_clean() ) {
1886                         // Could not remove output buffer handler; abort now
1887                         // to avoid getting in some kind of infinite loop.
1888                         break;
1889                 }
1890                 if ( $resetGzipEncoding ) {
1891                         if ( $status['name'] == 'ob_gzhandler' ) {
1892                                 // Reset the 'Content-Encoding' field set by this handler
1893                                 // so we can start fresh.
1894                                 header_remove( 'Content-Encoding' );
1895                                 break;
1896                         }
1897                 }
1898         }
1899 }
1900
1901 /**
1902  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1903  *
1904  * Clear away output buffers, but keep the Content-Encoding header
1905  * produced by ob_gzhandler, if any.
1906  *
1907  * This should be used for HTTP 304 responses, where you need to
1908  * preserve the Content-Encoding header of the real result, but
1909  * also need to suppress the output of ob_gzhandler to keep to spec
1910  * and avoid breaking Firefox in rare cases where the headers and
1911  * body are broken over two packets.
1912  */
1913 function wfClearOutputBuffers() {
1914         wfResetOutputBuffers( false );
1915 }
1916
1917 /**
1918  * Converts an Accept-* header into an array mapping string values to quality
1919  * factors
1920  *
1921  * @param string $accept
1922  * @param string $def Default
1923  * @return float[] Associative array of string => float pairs
1924  */
1925 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1926         # No arg means accept anything (per HTTP spec)
1927         if ( !$accept ) {
1928                 return array( $def => 1.0 );
1929         }
1930
1931         $prefs = array();
1932
1933         $parts = explode( ',', $accept );
1934
1935         foreach ( $parts as $part ) {
1936                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1937                 $values = explode( ';', trim( $part ) );
1938                 $match = array();
1939                 if ( count( $values ) == 1 ) {
1940                         $prefs[$values[0]] = 1.0;
1941                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1942                         $prefs[$values[0]] = floatval( $match[1] );
1943                 }
1944         }
1945
1946         return $prefs;
1947 }
1948
1949 /**
1950  * Checks if a given MIME type matches any of the keys in the given
1951  * array. Basic wildcards are accepted in the array keys.
1952  *
1953  * Returns the matching MIME type (or wildcard) if a match, otherwise
1954  * NULL if no match.
1955  *
1956  * @param string $type
1957  * @param array $avail
1958  * @return string
1959  * @private
1960  */
1961 function mimeTypeMatch( $type, $avail ) {
1962         if ( array_key_exists( $type, $avail ) ) {
1963                 return $type;
1964         } else {
1965                 $parts = explode( '/', $type );
1966                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
1967                         return $parts[0] . '/*';
1968                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1969                         return '*/*';
1970                 } else {
1971                         return null;
1972                 }
1973         }
1974 }
1975
1976 /**
1977  * Returns the 'best' match between a client's requested internet media types
1978  * and the server's list of available types. Each list should be an associative
1979  * array of type to preference (preference is a float between 0.0 and 1.0).
1980  * Wildcards in the types are acceptable.
1981  *
1982  * @param array $cprefs Client's acceptable type list
1983  * @param array $sprefs Server's offered types
1984  * @return string
1985  *
1986  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1987  * XXX: generalize to negotiate other stuff
1988  */
1989 function wfNegotiateType( $cprefs, $sprefs ) {
1990         $combine = array();
1991
1992         foreach ( array_keys( $sprefs ) as $type ) {
1993                 $parts = explode( '/', $type );
1994                 if ( $parts[1] != '*' ) {
1995                         $ckey = mimeTypeMatch( $type, $cprefs );
1996                         if ( $ckey ) {
1997                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1998                         }
1999                 }
2000         }
2001
2002         foreach ( array_keys( $cprefs ) as $type ) {
2003                 $parts = explode( '/', $type );
2004                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2005                         $skey = mimeTypeMatch( $type, $sprefs );
2006                         if ( $skey ) {
2007                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2008                         }
2009                 }
2010         }
2011
2012         $bestq = 0;
2013         $besttype = null;
2014
2015         foreach ( array_keys( $combine ) as $type ) {
2016                 if ( $combine[$type] > $bestq ) {
2017                         $besttype = $type;
2018                         $bestq = $combine[$type];
2019                 }
2020         }
2021
2022         return $besttype;
2023 }
2024
2025 /**
2026  * Reference-counted warning suppression
2027  *
2028  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
2029  * @param bool $end
2030  */
2031 function wfSuppressWarnings( $end = false ) {
2032         MediaWiki\suppressWarnings( $end );
2033 }
2034
2035 /**
2036  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
2037  * Restore error level to previous value
2038  */
2039 function wfRestoreWarnings() {
2040         MediaWiki\suppressWarnings( true );
2041 }
2042
2043 # Autodetect, convert and provide timestamps of various types
2044
2045 /**
2046  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2047  */
2048 define( 'TS_UNIX', 0 );
2049
2050 /**
2051  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2052  */
2053 define( 'TS_MW', 1 );
2054
2055 /**
2056  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2057  */
2058 define( 'TS_DB', 2 );
2059
2060 /**
2061  * RFC 2822 format, for E-mail and HTTP headers
2062  */
2063 define( 'TS_RFC2822', 3 );
2064
2065 /**
2066  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2067  *
2068  * This is used by Special:Export
2069  */
2070 define( 'TS_ISO_8601', 4 );
2071
2072 /**
2073  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2074  *
2075  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2076  *       DateTime tag and page 36 for the DateTimeOriginal and
2077  *       DateTimeDigitized tags.
2078  */
2079 define( 'TS_EXIF', 5 );
2080
2081 /**
2082  * Oracle format time.
2083  */
2084 define( 'TS_ORACLE', 6 );
2085
2086 /**
2087  * Postgres format time.
2088  */
2089 define( 'TS_POSTGRES', 7 );
2090
2091 /**
2092  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2093  */
2094 define( 'TS_ISO_8601_BASIC', 9 );
2095
2096 /**
2097  * Get a timestamp string in one of various formats
2098  *
2099  * @param mixed $outputtype A timestamp in one of the supported formats, the
2100  *   function will autodetect which format is supplied and act accordingly.
2101  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2102  * @return string|bool String / false The same date in the format specified in $outputtype or false
2103  */
2104 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2105         try {
2106                 $timestamp = new MWTimestamp( $ts );
2107                 return $timestamp->getTimestamp( $outputtype );
2108         } catch ( TimestampException $e ) {
2109                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2110                 return false;
2111         }
2112 }
2113
2114 /**
2115  * Return a formatted timestamp, or null if input is null.
2116  * For dealing with nullable timestamp columns in the database.
2117  *
2118  * @param int $outputtype
2119  * @param string $ts
2120  * @return string
2121  */
2122 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2123         if ( is_null( $ts ) ) {
2124                 return null;
2125         } else {
2126                 return wfTimestamp( $outputtype, $ts );
2127         }
2128 }
2129
2130 /**
2131  * Convenience function; returns MediaWiki timestamp for the present time.
2132  *
2133  * @return string
2134  */
2135 function wfTimestampNow() {
2136         # return NOW
2137         return wfTimestamp( TS_MW, time() );
2138 }
2139
2140 /**
2141  * Check if the operating system is Windows
2142  *
2143  * @return bool True if it's Windows, false otherwise.
2144  */
2145 function wfIsWindows() {
2146         static $isWindows = null;
2147         if ( $isWindows === null ) {
2148                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2149         }
2150         return $isWindows;
2151 }
2152
2153 /**
2154  * Check if we are running under HHVM
2155  *
2156  * @return bool
2157  */
2158 function wfIsHHVM() {
2159         return defined( 'HHVM_VERSION' );
2160 }
2161
2162 /**
2163  * Tries to get the system directory for temporary files. First
2164  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2165  * environment variables are then checked in sequence, then
2166  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2167  *
2168  * NOTE: When possible, use instead the tmpfile() function to create
2169  * temporary files to avoid race conditions on file creation, etc.
2170  *
2171  * @return string
2172  */
2173 function wfTempDir() {
2174         global $wgTmpDirectory;
2175
2176         if ( $wgTmpDirectory !== false ) {
2177                 return $wgTmpDirectory;
2178         }
2179
2180         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2181         $tmpDir[] = sys_get_temp_dir();
2182         $tmpDir[] = ini_get( 'upload_tmp_dir' );
2183
2184         foreach ( $tmpDir as $tmp ) {
2185                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2186                         return $tmp;
2187                 }
2188         }
2189         throw new MWException( 'No writable temporary directory could be found. ' .
2190                 'Please set $wgTmpDirectory to a writable directory.' );
2191 }
2192
2193 /**
2194  * Make directory, and make all parent directories if they don't exist
2195  *
2196  * @param string $dir Full path to directory to create
2197  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2198  * @param string $caller Optional caller param for debugging.
2199  * @throws MWException
2200  * @return bool
2201  */
2202 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2203         global $wgDirectoryMode;
2204
2205         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2206                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2207         }
2208
2209         if ( !is_null( $caller ) ) {
2210                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2211         }
2212
2213         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2214                 return true;
2215         }
2216
2217         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2218
2219         if ( is_null( $mode ) ) {
2220                 $mode = $wgDirectoryMode;
2221         }
2222
2223         // Turn off the normal warning, we're doing our own below
2224         MediaWiki\suppressWarnings();
2225         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2226         MediaWiki\restoreWarnings();
2227
2228         if ( !$ok ) {
2229                 // directory may have been created on another request since we last checked
2230                 if ( is_dir( $dir ) ) {
2231                         return true;
2232                 }
2233
2234                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2235                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2236         }
2237         return $ok;
2238 }
2239
2240 /**
2241  * Remove a directory and all its content.
2242  * Does not hide error.
2243  * @param string $dir
2244  */
2245 function wfRecursiveRemoveDir( $dir ) {
2246         wfDebug( __FUNCTION__ . "( $dir )\n" );
2247         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2248         if ( is_dir( $dir ) ) {
2249                 $objects = scandir( $dir );
2250                 foreach ( $objects as $object ) {
2251                         if ( $object != "." && $object != ".." ) {
2252                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2253                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2254                                 } else {
2255                                         unlink( $dir . '/' . $object );
2256                                 }
2257                         }
2258                 }
2259                 reset( $objects );
2260                 rmdir( $dir );
2261         }
2262 }
2263
2264 /**
2265  * @param int $nr The number to format
2266  * @param int $acc The number of digits after the decimal point, default 2
2267  * @param bool $round Whether or not to round the value, default true
2268  * @return string
2269  */
2270 function wfPercent( $nr, $acc = 2, $round = true ) {
2271         $ret = sprintf( "%.${acc}f", $nr );
2272         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2273 }
2274
2275 /**
2276  * Safety wrapper around ini_get() for boolean settings.
2277  * The values returned from ini_get() are pre-normalized for settings
2278  * set via php.ini or php_flag/php_admin_flag... but *not*
2279  * for those set via php_value/php_admin_value.
2280  *
2281  * It's fairly common for people to use php_value instead of php_flag,
2282  * which can leave you with an 'off' setting giving a false positive
2283  * for code that just takes the ini_get() return value as a boolean.
2284  *
2285  * To make things extra interesting, setting via php_value accepts
2286  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2287  * Unrecognized values go false... again opposite PHP's own coercion
2288  * from string to bool.
2289  *
2290  * Luckily, 'properly' set settings will always come back as '0' or '1',
2291  * so we only have to worry about them and the 'improper' settings.
2292  *
2293  * I frickin' hate PHP... :P
2294  *
2295  * @param string $setting
2296  * @return bool
2297  */
2298 function wfIniGetBool( $setting ) {
2299         $val = strtolower( ini_get( $setting ) );
2300         // 'on' and 'true' can't have whitespace around them, but '1' can.
2301         return $val == 'on'
2302                 || $val == 'true'
2303                 || $val == 'yes'
2304                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2305 }
2306
2307 /**
2308  * Windows-compatible version of escapeshellarg()
2309  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2310  * function puts single quotes in regardless of OS.
2311  *
2312  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2313  * earlier distro releases of PHP)
2314  *
2315  * @param string ... strings to escape and glue together, or a single array of strings parameter
2316  * @return string
2317  */
2318 function wfEscapeShellArg( /*...*/ ) {
2319         wfInitShellLocale();
2320
2321         $args = func_get_args();
2322         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2323                 // If only one argument has been passed, and that argument is an array,
2324                 // treat it as a list of arguments
2325                 $args = reset( $args );
2326         }
2327
2328         $first = true;
2329         $retVal = '';
2330         foreach ( $args as $arg ) {
2331                 if ( !$first ) {
2332                         $retVal .= ' ';
2333                 } else {
2334                         $first = false;
2335                 }
2336
2337                 if ( wfIsWindows() ) {
2338                         // Escaping for an MSVC-style command line parser and CMD.EXE
2339                         // @codingStandardsIgnoreStart For long URLs
2340                         // Refs:
2341                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2342                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2343                         //  * Bug #13518
2344                         //  * CR r63214
2345                         // Double the backslashes before any double quotes. Escape the double quotes.
2346                         // @codingStandardsIgnoreEnd
2347                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2348                         $arg = '';
2349                         $iteration = 0;
2350                         foreach ( $tokens as $token ) {
2351                                 if ( $iteration % 2 == 1 ) {
2352                                         // Delimiter, a double quote preceded by zero or more slashes
2353                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2354                                 } elseif ( $iteration % 4 == 2 ) {
2355                                         // ^ in $token will be outside quotes, need to be escaped
2356                                         $arg .= str_replace( '^', '^^', $token );
2357                                 } else { // $iteration % 4 == 0
2358                                         // ^ in $token will appear inside double quotes, so leave as is
2359                                         $arg .= $token;
2360                                 }
2361                                 $iteration++;
2362                         }
2363                         // Double the backslashes before the end of the string, because
2364                         // we will soon add a quote
2365                         $m = array();
2366                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2367                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2368                         }
2369
2370                         // Add surrounding quotes
2371                         $retVal .= '"' . $arg . '"';
2372                 } else {
2373                         $retVal .= escapeshellarg( $arg );
2374                 }
2375         }
2376         return $retVal;
2377 }
2378
2379 /**
2380  * Check if wfShellExec() is effectively disabled via php.ini config
2381  *
2382  * @return bool|string False or one of (safemode,disabled)
2383  * @since 1.22
2384  */
2385 function wfShellExecDisabled() {
2386         static $disabled = null;
2387         if ( is_null( $disabled ) ) {
2388                 if ( wfIniGetBool( 'safe_mode' ) ) {
2389                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2390                         $disabled = 'safemode';
2391                 } elseif ( !function_exists( 'proc_open' ) ) {
2392                         wfDebug( "proc_open() is disabled\n" );
2393                         $disabled = 'disabled';
2394                 } else {
2395                         $disabled = false;
2396                 }
2397         }
2398         return $disabled;
2399 }
2400
2401 /**
2402  * Execute a shell command, with time and memory limits mirrored from the PHP
2403  * configuration if supported.
2404  *
2405  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2406  *   or an array of unescaped arguments, in which case each value will be escaped
2407  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2408  * @param null|mixed &$retval Optional, will receive the program's exit code.
2409  *   (non-zero is usually failure). If there is an error from
2410  *   read, select, or proc_open(), this will be set to -1.
2411  * @param array $environ Optional environment variables which should be
2412  *   added to the executed command environment.
2413  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2414  *   this overwrites the global wgMaxShell* limits.
2415  * @param array $options Array of options:
2416  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2417  *     including errors from limit.sh
2418  *   - profileMethod: By default this function will profile based on the calling
2419  *     method. Set this to a string for an alternative method to profile from
2420  *
2421  * @return string Collected stdout as a string
2422  */
2423 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2424         $limits = array(), $options = array()
2425 ) {
2426         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2427                 $wgMaxShellWallClockTime, $wgShellCgroup;
2428
2429         $disabled = wfShellExecDisabled();
2430         if ( $disabled ) {
2431                 $retval = 1;
2432                 return $disabled == 'safemode' ?
2433                         'Unable to run external programs in safe mode.' :
2434                         'Unable to run external programs, proc_open() is disabled.';
2435         }
2436
2437         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2438         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2439
2440         wfInitShellLocale();
2441
2442         $envcmd = '';
2443         foreach ( $environ as $k => $v ) {
2444                 if ( wfIsWindows() ) {
2445                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2446                          * appear in the environment variable, so we must use carat escaping as documented in
2447                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2448                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2449                          * are listed there but doesn't appear to need it.
2450                          */
2451                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2452                 } else {
2453                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2454                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2455                          */
2456                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2457                 }
2458         }
2459         if ( is_array( $cmd ) ) {
2460                 $cmd = wfEscapeShellArg( $cmd );
2461         }
2462
2463         $cmd = $envcmd . $cmd;
2464
2465         $useLogPipe = false;
2466         if ( is_executable( '/bin/bash' ) ) {
2467                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2468                 if ( isset( $limits['walltime'] ) ) {
2469                         $wallTime = intval( $limits['walltime'] );
2470                 } elseif ( isset( $limits['time'] ) ) {
2471                         $wallTime = $time;
2472                 } else {
2473                         $wallTime = intval( $wgMaxShellWallClockTime );
2474                 }
2475                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2476                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2477
2478                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2479                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2480                                 escapeshellarg( $cmd ) . ' ' .
2481                                 escapeshellarg(
2482                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2483                                         "MW_CPU_LIMIT=$time; " .
2484                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2485                                         "MW_MEM_LIMIT=$mem; " .
2486                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2487                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2488                                         "MW_USE_LOG_PIPE=yes"
2489                                 );
2490                         $useLogPipe = true;
2491                 } elseif ( $includeStderr ) {
2492                         $cmd .= ' 2>&1';
2493                 }
2494         } elseif ( $includeStderr ) {
2495                 $cmd .= ' 2>&1';
2496         }
2497         wfDebug( "wfShellExec: $cmd\n" );
2498
2499         $desc = array(
2500                 0 => array( 'file', 'php://stdin', 'r' ),
2501                 1 => array( 'pipe', 'w' ),
2502                 2 => array( 'file', 'php://stderr', 'w' ) );
2503         if ( $useLogPipe ) {
2504                 $desc[3] = array( 'pipe', 'w' );
2505         }
2506         $pipes = null;
2507         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2508         $proc = proc_open( $cmd, $desc, $pipes );
2509         if ( !$proc ) {
2510                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2511                 $retval = -1;
2512                 return '';
2513         }
2514         $outBuffer = $logBuffer = '';
2515         $emptyArray = array();
2516         $status = false;
2517         $logMsg = false;
2518
2519         /* According to the documentation, it is possible for stream_select()
2520          * to fail due to EINTR. I haven't managed to induce this in testing
2521          * despite sending various signals. If it did happen, the error
2522          * message would take the form:
2523          *
2524          * stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2525          *
2526          * where [4] is the value of the macro EINTR and "Interrupted system
2527          * call" is string which according to the Linux manual is "possibly"
2528          * localised according to LC_MESSAGES.
2529          */
2530         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2531         $eintrMessage = "stream_select(): unable to select [$eintr]";
2532
2533         // Build a table mapping resource IDs to pipe FDs to work around a
2534         // PHP 5.3 issue in which stream_select() does not preserve array keys
2535         // <https://bugs.php.net/bug.php?id=53427>.
2536         $fds = array();
2537         foreach ( $pipes as $fd => $pipe ) {
2538                 $fds[(int)$pipe] = $fd;
2539         }
2540
2541         $running = true;
2542         $timeout = null;
2543         $numReadyPipes = 0;
2544
2545         while ( $running === true || $numReadyPipes !== 0 ) {
2546                 if ( $running ) {
2547                         $status = proc_get_status( $proc );
2548                         // If the process has terminated, switch to nonblocking selects
2549                         // for getting any data still waiting to be read.
2550                         if ( !$status['running'] ) {
2551                                 $running = false;
2552                                 $timeout = 0;
2553                         }
2554                 }
2555
2556                 $readyPipes = $pipes;
2557
2558                 // Clear last error
2559                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2560                 @trigger_error( '' );
2561                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2562                 if ( $numReadyPipes === false ) {
2563                         // @codingStandardsIgnoreEnd
2564                         $error = error_get_last();
2565                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2566                                 continue;
2567                         } else {
2568                                 trigger_error( $error['message'], E_USER_WARNING );
2569                                 $logMsg = $error['message'];
2570                                 break;
2571                         }
2572                 }
2573                 foreach ( $readyPipes as $pipe ) {
2574                         $block = fread( $pipe, 65536 );
2575                         $fd = $fds[(int)$pipe];
2576                         if ( $block === '' ) {
2577                                 // End of file
2578                                 fclose( $pipes[$fd] );
2579                                 unset( $pipes[$fd] );
2580                                 if ( !$pipes ) {
2581                                         break 2;
2582                                 }
2583                         } elseif ( $block === false ) {
2584                                 // Read error
2585                                 $logMsg = "Error reading from pipe";
2586                                 break 2;
2587                         } elseif ( $fd == 1 ) {
2588                                 // From stdout
2589                                 $outBuffer .= $block;
2590                         } elseif ( $fd == 3 ) {
2591                                 // From log FD
2592                                 $logBuffer .= $block;
2593                                 if ( strpos( $block, "\n" ) !== false ) {
2594                                         $lines = explode( "\n", $logBuffer );
2595                                         $logBuffer = array_pop( $lines );
2596                                         foreach ( $lines as $line ) {
2597                                                 wfDebugLog( 'exec', $line );
2598                                         }
2599                                 }
2600                         }
2601                 }
2602         }
2603
2604         foreach ( $pipes as $pipe ) {
2605                 fclose( $pipe );
2606         }
2607
2608         // Use the status previously collected if possible, since proc_get_status()
2609         // just calls waitpid() which will not return anything useful the second time.
2610         if ( $running ) {
2611                 $status = proc_get_status( $proc );
2612         }
2613
2614         if ( $logMsg !== false ) {
2615                 // Read/select error
2616                 $retval = -1;
2617                 proc_close( $proc );
2618         } elseif ( $status['signaled'] ) {
2619                 $logMsg = "Exited with signal {$status['termsig']}";
2620                 $retval = 128 + $status['termsig'];
2621                 proc_close( $proc );
2622         } else {
2623                 if ( $status['running'] ) {
2624                         $retval = proc_close( $proc );
2625                 } else {
2626                         $retval = $status['exitcode'];
2627                         proc_close( $proc );
2628                 }
2629                 if ( $retval == 127 ) {
2630                         $logMsg = "Possibly missing executable file";
2631                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2632                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2633                 }
2634         }
2635
2636         if ( $logMsg !== false ) {
2637                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2638         }
2639
2640         return $outBuffer;
2641 }
2642
2643 /**
2644  * Execute a shell command, returning both stdout and stderr. Convenience
2645  * function, as all the arguments to wfShellExec can become unwieldy.
2646  *
2647  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2648  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2649  *   or an array of unescaped arguments, in which case each value will be escaped
2650  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2651  * @param null|mixed &$retval Optional, will receive the program's exit code.
2652  *   (non-zero is usually failure)
2653  * @param array $environ Optional environment variables which should be
2654  *   added to the executed command environment.
2655  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2656  *   this overwrites the global wgMaxShell* limits.
2657  * @return string Collected stdout and stderr as a string
2658  */
2659 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2660         return wfShellExec( $cmd, $retval, $environ, $limits,
2661                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2662 }
2663
2664 /**
2665  * Workaround for http://bugs.php.net/bug.php?id=45132
2666  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2667  */
2668 function wfInitShellLocale() {
2669         static $done = false;
2670         if ( $done ) {
2671                 return;
2672         }
2673         $done = true;
2674         global $wgShellLocale;
2675         if ( !wfIniGetBool( 'safe_mode' ) ) {
2676                 putenv( "LC_CTYPE=$wgShellLocale" );
2677                 setlocale( LC_CTYPE, $wgShellLocale );
2678         }
2679 }
2680
2681 /**
2682  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2683  * Note that $parameters should be a flat array and an option with an argument
2684  * should consist of two consecutive items in the array (do not use "--option value").
2685  *
2686  * @param string $script MediaWiki cli script path
2687  * @param array $parameters Arguments and options to the script
2688  * @param array $options Associative array of options:
2689  *              'php': The path to the php executable
2690  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2691  * @return string
2692  */
2693 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2694         global $wgPhpCli;
2695         // Give site config file a chance to run the script in a wrapper.
2696         // The caller may likely want to call wfBasename() on $script.
2697         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2698         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2699         if ( isset( $options['wrapper'] ) ) {
2700                 $cmd[] = $options['wrapper'];
2701         }
2702         $cmd[] = $script;
2703         // Escape each parameter for shell
2704         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
2705 }
2706
2707 /**
2708  * wfMerge attempts to merge differences between three texts.
2709  * Returns true for a clean merge and false for failure or a conflict.
2710  *
2711  * @param string $old
2712  * @param string $mine
2713  * @param string $yours
2714  * @param string $result
2715  * @return bool
2716  */
2717 function wfMerge( $old, $mine, $yours, &$result ) {
2718         global $wgDiff3;
2719
2720         # This check may also protect against code injection in
2721         # case of broken installations.
2722         MediaWiki\suppressWarnings();
2723         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2724         MediaWiki\restoreWarnings();
2725
2726         if ( !$haveDiff3 ) {
2727                 wfDebug( "diff3 not found\n" );
2728                 return false;
2729         }
2730
2731         # Make temporary files
2732         $td = wfTempDir();
2733         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2734         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2735         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2736
2737         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2738         #       a newline character. To avoid this, we normalize the trailing whitespace before
2739         #       creating the diff.
2740
2741         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2742         fclose( $oldtextFile );
2743         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2744         fclose( $mytextFile );
2745         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2746         fclose( $yourtextFile );
2747
2748         # Check for a conflict
2749         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
2750                 $oldtextName, $yourtextName );
2751         $handle = popen( $cmd, 'r' );
2752
2753         if ( fgets( $handle, 1024 ) ) {
2754                 $conflict = true;
2755         } else {
2756                 $conflict = false;
2757         }
2758         pclose( $handle );
2759
2760         # Merge differences
2761         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2762                 $oldtextName, $yourtextName );
2763         $handle = popen( $cmd, 'r' );
2764         $result = '';
2765         do {
2766                 $data = fread( $handle, 8192 );
2767                 if ( strlen( $data ) == 0 ) {
2768                         break;
2769                 }
2770                 $result .= $data;
2771         } while ( true );
2772         pclose( $handle );
2773         unlink( $mytextName );
2774         unlink( $oldtextName );
2775         unlink( $yourtextName );
2776
2777         if ( $result === '' && $old !== '' && !$conflict ) {
2778                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2779                 $conflict = true;
2780         }
2781         return !$conflict;
2782 }
2783
2784 /**
2785  * Returns unified plain-text diff of two texts.
2786  * "Useful" for machine processing of diffs.
2787  *
2788  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2789  *
2790  * @param string $before The text before the changes.
2791  * @param string $after The text after the changes.
2792  * @param string $params Command-line options for the diff command.
2793  * @return string Unified diff of $before and $after
2794  */
2795 function wfDiff( $before, $after, $params = '-u' ) {
2796         if ( $before == $after ) {
2797                 return '';
2798         }
2799
2800         global $wgDiff;
2801         MediaWiki\suppressWarnings();
2802         $haveDiff = $wgDiff && file_exists( $wgDiff );
2803         MediaWiki\restoreWarnings();
2804
2805         # This check may also protect against code injection in
2806         # case of broken installations.
2807         if ( !$haveDiff ) {
2808                 wfDebug( "diff executable not found\n" );
2809                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2810                 $format = new UnifiedDiffFormatter();
2811                 return $format->format( $diffs );
2812         }
2813
2814         # Make temporary files
2815         $td = wfTempDir();
2816         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2817         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2818
2819         fwrite( $oldtextFile, $before );
2820         fclose( $oldtextFile );
2821         fwrite( $newtextFile, $after );
2822         fclose( $newtextFile );
2823
2824         // Get the diff of the two files
2825         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2826
2827         $h = popen( $cmd, 'r' );
2828         if ( !$h ) {
2829                 unlink( $oldtextName );
2830                 unlink( $newtextName );
2831                 throw new Exception( __METHOD__ . '(): popen() failed' );
2832         }
2833
2834         $diff = '';
2835
2836         do {
2837                 $data = fread( $h, 8192 );
2838                 if ( strlen( $data ) == 0 ) {
2839                         break;
2840                 }
2841                 $diff .= $data;
2842         } while ( true );
2843
2844         // Clean up
2845         pclose( $h );
2846         unlink( $oldtextName );
2847         unlink( $newtextName );
2848
2849         // Kill the --- and +++ lines. They're not useful.
2850         $diff_lines = explode( "\n", $diff );
2851         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2852                 unset( $diff_lines[0] );
2853         }
2854         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2855                 unset( $diff_lines[1] );
2856         }
2857
2858         $diff = implode( "\n", $diff_lines );
2859
2860         return $diff;
2861 }
2862
2863 /**
2864  * This function works like "use VERSION" in Perl, the program will die with a
2865  * backtrace if the current version of PHP is less than the version provided
2866  *
2867  * This is useful for extensions which due to their nature are not kept in sync
2868  * with releases, and might depend on other versions of PHP than the main code
2869  *
2870  * Note: PHP might die due to parsing errors in some cases before it ever
2871  *       manages to call this function, such is life
2872  *
2873  * @see perldoc -f use
2874  *
2875  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2876  * @throws MWException
2877  */
2878 function wfUsePHP( $req_ver ) {
2879         $php_ver = PHP_VERSION;
2880
2881         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2882                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2883         }
2884 }
2885
2886 /**
2887  * This function works like "use VERSION" in Perl except it checks the version
2888  * of MediaWiki, the program will die with a backtrace if the current version
2889  * of MediaWiki is less than the version provided.
2890  *
2891  * This is useful for extensions which due to their nature are not kept in sync
2892  * with releases
2893  *
2894  * Note: Due to the behavior of PHP's version_compare() which is used in this
2895  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2896  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2897  * targeted version number. For example if you wanted to allow any variation
2898  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2899  * not result in the same comparison due to the internal logic of
2900  * version_compare().
2901  *
2902  * @see perldoc -f use
2903  *
2904  * @deprecated since 1.26, use the "requires' property of extension.json
2905  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2906  * @throws MWException
2907  */
2908 function wfUseMW( $req_ver ) {
2909         global $wgVersion;
2910
2911         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2912                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2913         }
2914 }
2915
2916 /**
2917  * Return the final portion of a pathname.
2918  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2919  * http://bugs.php.net/bug.php?id=33898
2920  *
2921  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2922  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2923  *
2924  * @param string $path
2925  * @param string $suffix String to remove if present
2926  * @return string
2927  */
2928 function wfBaseName( $path, $suffix = '' ) {
2929         if ( $suffix == '' ) {
2930                 $encSuffix = '';
2931         } else {
2932                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2933         }
2934
2935         $matches = array();
2936         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2937                 return $matches[1];
2938         } else {
2939                 return '';
2940         }
2941 }
2942
2943 /**
2944  * Generate a relative path name to the given file.
2945  * May explode on non-matching case-insensitive paths,
2946  * funky symlinks, etc.
2947  *
2948  * @param string $path Absolute destination path including target filename
2949  * @param string $from Absolute source path, directory only
2950  * @return string
2951  */
2952 function wfRelativePath( $path, $from ) {
2953         // Normalize mixed input on Windows...
2954         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2955         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2956
2957         // Trim trailing slashes -- fix for drive root
2958         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2959         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2960
2961         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2962         $against = explode( DIRECTORY_SEPARATOR, $from );
2963
2964         if ( $pieces[0] !== $against[0] ) {
2965                 // Non-matching Windows drive letters?
2966                 // Return a full path.
2967                 return $path;
2968         }
2969
2970         // Trim off common prefix
2971         while ( count( $pieces ) && count( $against )
2972                 && $pieces[0] == $against[0] ) {
2973                 array_shift( $pieces );
2974                 array_shift( $against );
2975         }
2976
2977         // relative dots to bump us to the parent
2978         while ( count( $against ) ) {
2979                 array_unshift( $pieces, '..' );
2980                 array_shift( $against );
2981         }
2982
2983         array_push( $pieces, wfBaseName( $path ) );
2984
2985         return implode( DIRECTORY_SEPARATOR, $pieces );
2986 }
2987
2988 /**
2989  * Convert an arbitrarily-long digit string from one numeric base
2990  * to another, optionally zero-padding to a minimum column width.
2991  *
2992  * Supports base 2 through 36; digit values 10-36 are represented
2993  * as lowercase letters a-z. Input is case-insensitive.
2994  *
2995  * @deprecated 1.27 Use Wikimedia\base_convert() directly
2996  *
2997  * @param string $input Input number
2998  * @param int $sourceBase Base of the input number
2999  * @param int $destBase Desired base of the output
3000  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3001  * @param bool $lowercase Whether to output in lowercase or uppercase
3002  * @param string $engine Either "gmp", "bcmath", or "php"
3003  * @return string|bool The output number as a string, or false on error
3004  */
3005 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3006         $lowercase = true, $engine = 'auto'
3007 ) {
3008         return Wikimedia\base_convert( $input, $sourceBase, $destBase, $pad, $lowercase, $engine );
3009 }
3010
3011 /**
3012  * Check if there is sufficient entropy in php's built-in session generation
3013  *
3014  * @deprecated since 1.27, PHP's session generation isn't used with
3015  *  MediaWiki\\Session\\SessionManager
3016  * @return bool True = there is sufficient entropy
3017  */
3018 function wfCheckEntropy() {
3019         wfDeprecated( __FUNCTION__, '1.27' );
3020         return (
3021                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3022                         || ini_get( 'session.entropy_file' )
3023                 )
3024                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3025 }
3026
3027 /**
3028  * @deprecated since 1.27, PHP's session generation isn't used with
3029  *  MediaWiki\\Session\\SessionManager
3030  */
3031 function wfFixSessionID() {
3032         wfDeprecated( __FUNCTION__, '1.27' );
3033 }
3034
3035 /**
3036  * Reset the session id
3037  *
3038  * @deprecated since 1.27, use MediaWiki\\Session\\SessionManager instead
3039  * @since 1.22
3040  */
3041 function wfResetSessionID() {
3042         wfDeprecated( __FUNCTION__, '1.27' );
3043         $session = SessionManager::getGlobalSession();
3044         $delay = $session->delaySave();
3045
3046         $session->resetId();
3047
3048         // Make sure a session is started, since that's what the old
3049         // wfResetSessionID() did.
3050         if ( session_id() !== $session->getId() ) {
3051                 wfSetupSession( $session->getId() );
3052         }
3053
3054         ScopedCallback::consume( $delay );
3055 }
3056
3057 /**
3058  * Initialise php session
3059  *
3060  * @deprecated since 1.27, use MediaWiki\\Session\\SessionManager instead.
3061  *  Generally, "using" SessionManager will be calling ->getSessionById() or
3062  *  ::getGlobalSession() (depending on whether you were passing $sessionId
3063  *  here), then calling $session->persist().
3064  * @param bool|string $sessionId
3065  */
3066 function wfSetupSession( $sessionId = false ) {
3067         wfDeprecated( __FUNCTION__, '1.27' );
3068
3069         // If they're calling this, they probably want our session management even
3070         // if NO_SESSION was set for Setup.php.
3071         if ( !MediaWiki\Session\PHPSessionHandler::isInstalled() ) {
3072                 MediaWiki\Session\PHPSessionHandler::install( SessionManager::singleton() );
3073         }
3074
3075         if ( $sessionId ) {
3076                 session_id( $sessionId );
3077         }
3078
3079         $session = SessionManager::getGlobalSession();
3080         $session->persist();
3081
3082         if ( session_id() !== $session->getId() ) {
3083                 session_id( $session->getId() );
3084         }
3085         MediaWiki\quietCall( 'session_cache_limiter', 'private, must-revalidate' );
3086         MediaWiki\quietCall( 'session_start' );
3087 }
3088
3089 /**
3090  * Get an object from the precompiled serialized directory
3091  *
3092  * @param string $name
3093  * @return mixed The variable on success, false on failure
3094  */
3095 function wfGetPrecompiledData( $name ) {
3096         global $IP;
3097
3098         $file = "$IP/serialized/$name";
3099         if ( file_exists( $file ) ) {
3100                 $blob = file_get_contents( $file );
3101                 if ( $blob ) {
3102                         return unserialize( $blob );
3103                 }
3104         }
3105         return false;
3106 }
3107
3108 /**
3109  * Make a cache key for the local wiki.
3110  *
3111  * @param string $args,...
3112  * @return string
3113  */
3114 function wfMemcKey( /*...*/ ) {
3115         return call_user_func_array(
3116                 array( ObjectCache::getLocalClusterInstance(), 'makeKey' ),
3117                 func_get_args()
3118         );
3119 }
3120
3121 /**
3122  * Make a cache key for a foreign DB.
3123  *
3124  * Must match what wfMemcKey() would produce in context of the foreign wiki.
3125  *
3126  * @param string $db
3127  * @param string $prefix
3128  * @param string $args,...
3129  * @return string
3130  */
3131 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3132         $args = array_slice( func_get_args(), 2 );
3133         $keyspace = $prefix ? "$db-$prefix" : $db;
3134         return call_user_func_array(
3135                 array( ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ),
3136                 array( $keyspace, $args )
3137         );
3138 }
3139
3140 /**
3141  * Make a cache key with database-agnostic prefix.
3142  *
3143  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3144  * instead. Must have a prefix as otherwise keys that use a database name
3145  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3146  *
3147  * @since 1.26
3148  * @param string $args,...
3149  * @return string
3150  */
3151 function wfGlobalCacheKey( /*...*/ ) {
3152         return call_user_func_array(
3153                 array( ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ),
3154                 func_get_args()
3155         );
3156 }
3157
3158 /**
3159  * Get an ASCII string identifying this wiki
3160  * This is used as a prefix in memcached keys
3161  *
3162  * @return string
3163  */
3164 function wfWikiID() {
3165         global $wgDBprefix, $wgDBname;
3166         if ( $wgDBprefix ) {
3167                 return "$wgDBname-$wgDBprefix";
3168         } else {
3169                 return $wgDBname;
3170         }
3171 }
3172
3173 /**
3174  * Split a wiki ID into DB name and table prefix
3175  *
3176  * @param string $wiki
3177  *
3178  * @return array
3179  */
3180 function wfSplitWikiID( $wiki ) {
3181         $bits = explode( '-', $wiki, 2 );
3182         if ( count( $bits ) < 2 ) {
3183                 $bits[] = '';
3184         }
3185         return $bits;
3186 }
3187
3188 /**
3189  * Get a Database object.
3190  *
3191  * @param int $db Index of the connection to get. May be DB_MASTER for the
3192  *            master (for write queries), DB_SLAVE for potentially lagged read
3193  *            queries, or an integer >= 0 for a particular server.
3194  *
3195  * @param string|string[] $groups Query groups. An array of group names that this query
3196  *                belongs to. May contain a single string if the query is only
3197  *                in one group.
3198  *
3199  * @param string|bool $wiki The wiki ID, or false for the current wiki
3200  *
3201  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3202  * will always return the same object, unless the underlying connection or load
3203  * balancer is manually destroyed.
3204  *
3205  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3206  * updater to ensure that a proper database is being updated.
3207  *
3208  * @return DatabaseBase
3209  */
3210 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3211         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3212 }
3213
3214 /**
3215  * Get a load balancer object.
3216  *
3217  * @param string|bool $wiki Wiki ID, or false for the current wiki
3218  * @return LoadBalancer
3219  */
3220 function wfGetLB( $wiki = false ) {
3221         return wfGetLBFactory()->getMainLB( $wiki );
3222 }
3223
3224 /**
3225  * Get the load balancer factory object
3226  *
3227  * @return LBFactory
3228  */
3229 function wfGetLBFactory() {
3230         return LBFactory::singleton();
3231 }
3232
3233 /**
3234  * Find a file.
3235  * Shortcut for RepoGroup::singleton()->findFile()
3236  *
3237  * @param string $title String or Title object
3238  * @param array $options Associative array of options (see RepoGroup::findFile)
3239  * @return File|bool File, or false if the file does not exist
3240  */
3241 function wfFindFile( $title, $options = array() ) {
3242         return RepoGroup::singleton()->findFile( $title, $options );
3243 }
3244
3245 /**
3246  * Get an object referring to a locally registered file.
3247  * Returns a valid placeholder object if the file does not exist.
3248  *
3249  * @param Title|string $title
3250  * @return LocalFile|null A File, or null if passed an invalid Title
3251  */
3252 function wfLocalFile( $title ) {
3253         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3254 }
3255
3256 /**
3257  * Should low-performance queries be disabled?
3258  *
3259  * @return bool
3260  * @codeCoverageIgnore
3261  */
3262 function wfQueriesMustScale() {
3263         global $wgMiserMode;
3264         return $wgMiserMode
3265                 || ( SiteStats::pages() > 100000
3266                 && SiteStats::edits() > 1000000
3267                 && SiteStats::users() > 10000 );
3268 }
3269
3270 /**
3271  * Get the path to a specified script file, respecting file
3272  * extensions; this is a wrapper around $wgScriptPath etc.
3273  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3274  *
3275  * @param string $script Script filename, sans extension
3276  * @return string
3277  */
3278 function wfScript( $script = 'index' ) {
3279         global $wgScriptPath, $wgScript, $wgLoadScript;
3280         if ( $script === 'index' ) {
3281                 return $wgScript;
3282         } elseif ( $script === 'load' ) {
3283                 return $wgLoadScript;
3284         } else {
3285                 return "{$wgScriptPath}/{$script}.php";
3286         }
3287 }
3288
3289 /**
3290  * Get the script URL.
3291  *
3292  * @return string Script URL
3293  */
3294 function wfGetScriptUrl() {
3295         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3296                 /* as it was called, minus the query string.
3297                  *
3298                  * Some sites use Apache rewrite rules to handle subdomains,
3299                  * and have PHP set up in a weird way that causes PHP_SELF
3300                  * to contain the rewritten URL instead of the one that the
3301                  * outside world sees.
3302                  *
3303                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
3304                  * provides containing the "before" URL.
3305                  */
3306                 return $_SERVER['SCRIPT_NAME'];
3307         } else {
3308                 return $_SERVER['URL'];
3309         }
3310 }
3311
3312 /**
3313  * Convenience function converts boolean values into "true"
3314  * or "false" (string) values
3315  *
3316  * @param bool $value
3317  * @return string
3318  */
3319 function wfBoolToStr( $value ) {
3320         return $value ? 'true' : 'false';
3321 }
3322
3323 /**
3324  * Get a platform-independent path to the null file, e.g. /dev/null
3325  *
3326  * @return string
3327  */
3328 function wfGetNull() {
3329         return wfIsWindows() ? 'NUL' : '/dev/null';
3330 }
3331
3332 /**
3333  * Waits for the slaves to catch up to the master position
3334  *
3335  * Use this when updating very large numbers of rows, as in maintenance scripts,
3336  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3337  *
3338  * By default this waits on the main DB cluster of the current wiki.
3339  * If $cluster is set to "*" it will wait on all DB clusters, including
3340  * external ones. If the lag being waiting on is caused by the code that
3341  * does this check, it makes since to use $ifWritesSince, particularly if
3342  * cluster is "*", to avoid excess overhead.
3343  *
3344  * Never call this function after a big DB write that is still in a transaction.
3345  * This only makes sense after the possible lag inducing changes were committed.
3346  *
3347  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3348  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3349  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3350  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3351  * @return bool Success (able to connect and no timeouts reached)
3352  * @deprecated since 1.27 Use LBFactory::waitForReplication
3353  */
3354 function wfWaitForSlaves(
3355         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3356 ) {
3357         if ( $timeout === null ) {
3358                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3359         }
3360
3361         if ( $cluster === '*' ) {
3362                 $cluster = false;
3363                 $wiki = false;
3364         } elseif ( $wiki === false ) {
3365                 $wiki = wfWikiID();
3366         }
3367
3368         try {
3369                 wfGetLBFactory()->waitForReplication( array(
3370                         'wiki' => $wiki,
3371                         'cluster' => $cluster,
3372                         'timeout' => $timeout,
3373                         // B/C: first argument used to be "max seconds of lag"; ignore such values
3374                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
3375                 ) );
3376         } catch ( DBReplicationWaitError $e ) {
3377                 return false;
3378         }
3379
3380         return true;
3381 }
3382
3383 /**
3384  * Count down from $seconds to zero on the terminal, with a one-second pause
3385  * between showing each number. For use in command-line scripts.
3386  *
3387  * @codeCoverageIgnore
3388  * @param int $seconds
3389  */
3390 function wfCountDown( $seconds ) {
3391         for ( $i = $seconds; $i >= 0; $i-- ) {
3392                 if ( $i != $seconds ) {
3393                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3394                 }
3395                 echo $i;
3396                 flush();
3397                 if ( $i ) {
3398                         sleep( 1 );
3399                 }
3400         }
3401         echo "\n";
3402 }
3403
3404 /**
3405  * Replace all invalid characters with -
3406  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3407  * By default, $wgIllegalFileChars = ':'
3408  *
3409  * @param string $name Filename to process
3410  * @return string
3411  */
3412 function wfStripIllegalFilenameChars( $name ) {
3413         global $wgIllegalFileChars;
3414         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3415         $name = wfBaseName( $name );
3416         $name = preg_replace(
3417                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3418                 '-',
3419                 $name
3420         );
3421         return $name;
3422 }
3423
3424 /**
3425  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3426  *
3427  * @return int Resulting value of the memory limit.
3428  */
3429 function wfMemoryLimit() {
3430         global $wgMemoryLimit;
3431         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3432         if ( $memlimit != -1 ) {
3433                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3434                 if ( $conflimit == -1 ) {
3435                         wfDebug( "Removing PHP's memory limit\n" );
3436                         MediaWiki\suppressWarnings();
3437                         ini_set( 'memory_limit', $conflimit );
3438                         MediaWiki\restoreWarnings();
3439                         return $conflimit;
3440                 } elseif ( $conflimit > $memlimit ) {
3441                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3442                         MediaWiki\suppressWarnings();
3443                         ini_set( 'memory_limit', $conflimit );
3444                         MediaWiki\restoreWarnings();
3445                         return $conflimit;
3446                 }
3447         }
3448         return $memlimit;
3449 }
3450
3451 /**
3452  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3453  *
3454  * @return int Prior time limit
3455  * @since 1.26
3456  */
3457 function wfTransactionalTimeLimit() {
3458         global $wgTransactionalTimeLimit;
3459
3460         $timeLimit = ini_get( 'max_execution_time' );
3461         // Note that CLI scripts use 0
3462         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3463                 set_time_limit( $wgTransactionalTimeLimit );
3464         }
3465
3466         ignore_user_abort( true ); // ignore client disconnects
3467
3468         return $timeLimit;
3469 }
3470
3471 /**
3472  * Converts shorthand byte notation to integer form
3473  *
3474  * @param string $string
3475  * @param int $default Returned if $string is empty
3476  * @return int
3477  */
3478 function wfShorthandToInteger( $string = '', $default = -1 ) {
3479         $string = trim( $string );
3480         if ( $string === '' ) {
3481                 return $default;
3482         }
3483         $last = $string[strlen( $string ) - 1];
3484         $val = intval( $string );
3485         switch ( $last ) {
3486                 case 'g':
3487                 case 'G':
3488                         $val *= 1024;
3489                         // break intentionally missing
3490                 case 'm':
3491                 case 'M':
3492                         $val *= 1024;
3493                         // break intentionally missing
3494                 case 'k':
3495                 case 'K':
3496                         $val *= 1024;
3497         }
3498
3499         return $val;
3500 }
3501
3502 /**
3503  * Get the normalised IETF language tag
3504  * See unit test for examples.
3505  *
3506  * @param string $code The language code.
3507  * @return string The language code which complying with BCP 47 standards.
3508  */
3509 function wfBCP47( $code ) {
3510         $codeSegment = explode( '-', $code );
3511         $codeBCP = array();
3512         foreach ( $codeSegment as $segNo => $seg ) {
3513                 // when previous segment is x, it is a private segment and should be lc
3514                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3515                         $codeBCP[$segNo] = strtolower( $seg );
3516                 // ISO 3166 country code
3517                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3518                         $codeBCP[$segNo] = strtoupper( $seg );
3519                 // ISO 15924 script code
3520                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3521                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3522                 // Use lowercase for other cases
3523                 } else {
3524                         $codeBCP[$segNo] = strtolower( $seg );
3525                 }
3526         }
3527         $langCode = implode( '-', $codeBCP );
3528         return $langCode;
3529 }
3530
3531 /**
3532  * Get a specific cache object.
3533  *
3534  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3535  * @return BagOStuff
3536  */
3537 function wfGetCache( $cacheType ) {
3538         return ObjectCache::getInstance( $cacheType );
3539 }
3540
3541 /**
3542  * Get the main cache object
3543  *
3544  * @return BagOStuff
3545  */
3546 function wfGetMainCache() {
3547         global $wgMainCacheType;
3548         return ObjectCache::getInstance( $wgMainCacheType );
3549 }
3550
3551 /**
3552  * Get the cache object used by the message cache
3553  *
3554  * @return BagOStuff
3555  */
3556 function wfGetMessageCacheStorage() {
3557         global $wgMessageCacheType;
3558         return ObjectCache::getInstance( $wgMessageCacheType );
3559 }
3560
3561 /**
3562  * Get the cache object used by the parser cache
3563  *
3564  * @return BagOStuff
3565  */
3566 function wfGetParserCacheStorage() {
3567         global $wgParserCacheType;
3568         return ObjectCache::getInstance( $wgParserCacheType );
3569 }
3570
3571 /**
3572  * Call hook functions defined in $wgHooks
3573  *
3574  * @param string $event Event name
3575  * @param array $args Parameters passed to hook functions
3576  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3577  *
3578  * @return bool True if no handler aborted the hook
3579  * @deprecated 1.25 - use Hooks::run
3580  */
3581 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3582         return Hooks::run( $event, $args, $deprecatedVersion );
3583 }
3584
3585 /**
3586  * Wrapper around php's unpack.
3587  *
3588  * @param string $format The format string (See php's docs)
3589  * @param string $data A binary string of binary data
3590  * @param int|bool $length The minimum length of $data or false. This is to
3591  *      prevent reading beyond the end of $data. false to disable the check.
3592  *
3593  * Also be careful when using this function to read unsigned 32 bit integer
3594  * because php might make it negative.
3595  *
3596  * @throws MWException If $data not long enough, or if unpack fails
3597  * @return array Associative array of the extracted data
3598  */
3599 function wfUnpack( $format, $data, $length = false ) {
3600         if ( $length !== false ) {
3601                 $realLen = strlen( $data );
3602                 if ( $realLen < $length ) {
3603                         throw new MWException( "Tried to use wfUnpack on a "
3604                                 . "string of length $realLen, but needed one "
3605                                 . "of at least length $length."
3606                         );
3607                 }
3608         }
3609
3610         MediaWiki\suppressWarnings();
3611         $result = unpack( $format, $data );
3612         MediaWiki\restoreWarnings();
3613
3614         if ( $result === false ) {
3615                 // If it cannot extract the packed data.
3616                 throw new MWException( "unpack could not unpack binary data" );
3617         }
3618         return $result;
3619 }
3620
3621 /**
3622  * Determine if an image exists on the 'bad image list'.
3623  *
3624  * The format of MediaWiki:Bad_image_list is as follows:
3625  *    * Only list items (lines starting with "*") are considered
3626  *    * The first link on a line must be a link to a bad image
3627  *    * Any subsequent links on the same line are considered to be exceptions,
3628  *      i.e. articles where the image may occur inline.
3629  *
3630  * @param string $name The image name to check
3631  * @param Title|bool $contextTitle The page on which the image occurs, if known
3632  * @param string $blacklist Wikitext of a file blacklist
3633  * @return bool
3634  */
3635 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3636         # Handle redirects; callers almost always hit wfFindFile() anyway,
3637         # so just use that method because it has a fast process cache.
3638         $file = wfFindFile( $name ); // get the final name
3639         $name = $file ? $file->getTitle()->getDBkey() : $name;
3640
3641         # Run the extension hook
3642         $bad = false;
3643         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
3644                 return $bad;
3645         }
3646
3647         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3648         $key = wfMemcKey( 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist ) );
3649         $badImages = $cache->get( $key );
3650
3651         if ( $badImages === false ) { // cache miss
3652                 if ( $blacklist === null ) {
3653                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3654                 }
3655                 # Build the list now
3656                 $badImages = array();
3657                 $lines = explode( "\n", $blacklist );
3658                 foreach ( $lines as $line ) {
3659                         # List items only
3660                         if ( substr( $line, 0, 1 ) !== '*' ) {
3661                                 continue;
3662                         }
3663
3664                         # Find all links
3665                         $m = array();
3666                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3667                                 continue;
3668                         }
3669
3670                         $exceptions = array();
3671                         $imageDBkey = false;
3672                         foreach ( $m[1] as $i => $titleText ) {
3673                                 $title = Title::newFromText( $titleText );
3674                                 if ( !is_null( $title ) ) {
3675                                         if ( $i == 0 ) {
3676                                                 $imageDBkey = $title->getDBkey();
3677                                         } else {
3678                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3679                                         }
3680                                 }
3681                         }
3682
3683                         if ( $imageDBkey !== false ) {
3684                                 $badImages[$imageDBkey] = $exceptions;
3685                         }
3686                 }
3687                 $cache->set( $key, $badImages, 60 );
3688         }
3689
3690         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3691         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3692
3693         return $bad;
3694 }
3695
3696 /**
3697  * Determine whether the client at a given source IP is likely to be able to
3698  * access the wiki via HTTPS.
3699  *
3700  * @param string $ip The IPv4/6 address in the normal human-readable form
3701  * @return bool
3702  */
3703 function wfCanIPUseHTTPS( $ip ) {
3704         $canDo = true;
3705         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
3706         return !!$canDo;
3707 }
3708
3709 /**
3710  * Determine input string is represents as infinity
3711  *
3712  * @param string $str The string to determine
3713  * @return bool
3714  * @since 1.25
3715  */
3716 function wfIsInfinity( $str ) {
3717         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
3718         return in_array( $str, $infinityValues );
3719 }
3720
3721 /**
3722  * Returns true if these thumbnail parameters match one that MediaWiki
3723  * requests from file description pages and/or parser output.
3724  *
3725  * $params is considered non-standard if they involve a non-standard
3726  * width or any non-default parameters aside from width and page number.
3727  * The number of possible files with standard parameters is far less than
3728  * that of all combinations; rate-limiting for them can thus be more generious.
3729  *
3730  * @param File $file
3731  * @param array $params
3732  * @return bool
3733  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3734  */
3735 function wfThumbIsStandard( File $file, array $params ) {
3736         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3737
3738         $multipliers = array( 1 );
3739         if ( $wgResponsiveImages ) {
3740                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3741                 // @see Linker::processResponsiveImages
3742                 $multipliers[] = 1.5;
3743                 $multipliers[] = 2;
3744         }
3745
3746         $handler = $file->getHandler();
3747         if ( !$handler || !isset( $params['width'] ) ) {
3748                 return false;
3749         }
3750
3751         $basicParams = array();
3752         if ( isset( $params['page'] ) ) {
3753                 $basicParams['page'] = $params['page'];
3754         }
3755
3756         $thumbLimits = array();
3757         $imageLimits = array();
3758         // Expand limits to account for multipliers
3759         foreach ( $multipliers as $multiplier ) {
3760                 $thumbLimits = array_merge( $thumbLimits, array_map(
3761                         function ( $width ) use ( $multiplier ) {
3762                                 return round( $width * $multiplier );
3763                         }, $wgThumbLimits )
3764                 );
3765                 $imageLimits = array_merge( $imageLimits, array_map(
3766                         function ( $pair ) use ( $multiplier ) {
3767                                 return array(
3768                                         round( $pair[0] * $multiplier ),
3769                                         round( $pair[1] * $multiplier ),
3770                                 );
3771                         }, $wgImageLimits )
3772                 );
3773         }
3774
3775         // Check if the width matches one of $wgThumbLimits
3776         if ( in_array( $params['width'], $thumbLimits ) ) {
3777                 $normalParams = $basicParams + array( 'width' => $params['width'] );
3778                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3779                 $handler->normaliseParams( $file, $normalParams );
3780         } else {
3781                 // If not, then check if the width matchs one of $wgImageLimits
3782                 $match = false;
3783                 foreach ( $imageLimits as $pair ) {
3784                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
3785                         // Decide whether the thumbnail should be scaled on width or height.
3786                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3787                         $handler->normaliseParams( $file, $normalParams );
3788                         // Check if this standard thumbnail size maps to the given width
3789                         if ( $normalParams['width'] == $params['width'] ) {
3790                                 $match = true;
3791                                 break;
3792                         }
3793                 }
3794                 if ( !$match ) {
3795                         return false; // not standard for description pages
3796                 }
3797         }
3798
3799         // Check that the given values for non-page, non-width, params are just defaults
3800         foreach ( $params as $key => $value ) {
3801                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3802                         return false;
3803                 }
3804         }
3805
3806         return true;
3807 }
3808
3809 /**
3810  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3811  *
3812  * Values that exist in both values will be combined with += (all values of the array
3813  * of $newValues will be added to the values of the array of $baseArray, while values,
3814  * that exists in both, the value of $baseArray will be used).
3815  *
3816  * @param array $baseArray The array where you want to add the values of $newValues to
3817  * @param array $newValues An array with new values
3818  * @return array The combined array
3819  * @since 1.26
3820  */
3821 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3822         // First merge items that are in both arrays
3823         foreach ( $baseArray as $name => &$groupVal ) {
3824                 if ( isset( $newValues[$name] ) ) {
3825                         $groupVal += $newValues[$name];
3826                 }
3827         }
3828         // Now add items that didn't exist yet
3829         $baseArray += $newValues;
3830
3831         return $baseArray;
3832 }