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