includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 use Liuggio\StatsdClient\Sender\SocketSender;
  28 use MediaWiki\Logger\LoggerFactory;
  29
  30 // Hide compatibility functions from Doxygen
  31 /// @cond
  32
  33 /**
  34  * Compatibility functions
  35  *
  36  * We support PHP 5.3.3 and up.
  37  * Re-implementations of newer functions or functions in non-standard
  38  * PHP extensions may be included here.
  39  */
  40
  41 if ( !function_exists( 'mb_substr' ) ) {
  42         /**
  43          * @codeCoverageIgnore
  44          * @see Fallback::mb_substr
  45          * @return string
  46          */
  47         function mb_substr( $str, $start, $count = 'end' ) {
  48                 return Fallback::mb_substr( $str, $start, $count );
  49         }
  50
  51         /**
  52          * @codeCoverageIgnore
  53          * @see Fallback::mb_substr_split_unicode
  54          * @return int
  55          */
  56         function mb_substr_split_unicode( $str, $splitPos ) {
  57                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  58         }
  59 }
  60
  61 if ( !function_exists( 'mb_strlen' ) ) {
  62         /**
  63          * @codeCoverageIgnore
  64          * @see Fallback::mb_strlen
  65          * @return int
  66          */
  67         function mb_strlen( $str, $enc = '' ) {
  68                 return Fallback::mb_strlen( $str, $enc );
  69         }
  70 }
  71
  72 if ( !function_exists( 'mb_strpos' ) ) {
  73         /**
  74          * @codeCoverageIgnore
  75          * @see Fallback::mb_strpos
  76          * @return int
  77          */
  78         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  79                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  80         }
  81 }
  82
  83 if ( !function_exists( 'mb_strrpos' ) ) {
  84         /**
  85          * @codeCoverageIgnore
  86          * @see Fallback::mb_strrpos
  87          * @return int
  88          */
  89         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  90                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  91         }
  92 }
  93
  94 // gzdecode function only exists in PHP >= 5.4.0
  95 // http://php.net/gzdecode
  96 if ( !function_exists( 'gzdecode' ) ) {
  97         /**
  98          * @codeCoverageIgnore
  99          * @param string $data
 100          * @return string
 101          */
 102         function gzdecode( $data ) {
 103                 return gzinflate( substr( $data, 10, -8 ) );
 104         }
 105 }
 106
 107 // hash_equals function only exists in PHP >= 5.6.0
 108 // http://php.net/hash_equals
 109 if ( !function_exists( 'hash_equals' ) ) {
 110         /**
 111          * Check whether a user-provided string is equal to a fixed-length secret string
 112          * without revealing bytes of the secret string through timing differences.
 113          *
 114          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 115          * function in C) is to compare corresponding bytes and stop at the first difference,
 116          * which would take longer for a partial match than for a complete mismatch. This
 117          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 118          * and the other may come from an attacker. Statistical analysis of timing measurements
 119          * over many requests may allow the attacker to guess the string's bytes one at a time
 120          * (and check his guesses) even if the timing differences are extremely small.
 121          *
 122          * When making such a security-sensitive comparison, it is essential that the sequence
 123          * in which instructions are executed and memory locations are accessed not depend on
 124          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 125          * the inevitable leakage of the string's length. That is generally known anyway as
 126          * a chararacteristic of the hash function used to compute the secret value.
 127          *
 128          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 129          *
 130          * @codeCoverageIgnore
 131          * @param string $known_string Fixed-length secret string to compare against
 132          * @param string $user_string User-provided string
 133          * @return bool True if the strings are the same, false otherwise
 134          */
 135         function hash_equals( $known_string, $user_string ) {
 136                 // Strict type checking as in PHP's native implementation
 137                 if ( !is_string( $known_string ) ) {
 138                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 139                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 140
 141                         return false;
 142                 }
 143
 144                 if ( !is_string( $user_string ) ) {
 145                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 146                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 147
 148                         return false;
 149                 }
 150
 151                 $known_string_len = strlen( $known_string );
 152                 if ( $known_string_len !== strlen( $user_string ) ) {
 153                         return false;
 154                 }
 155
 156                 $result = 0;
 157                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 158                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 159                 }
 160
 161                 return ( $result === 0 );
 162         }
 163 }
 164 /// @endcond
 165
 166 /**
 167  * Load an extension
 168  *
 169  * This queues an extension to be loaded through
 170  * the ExtensionRegistry system.
 171  *
 172  * @param string $ext Name of the extension to load
 173  * @param string|null $path Absolute path of where to find the extension.json file
 174  * @since 1.25
 175  */
 176 function wfLoadExtension( $ext, $path = null ) {
 177         if ( !$path ) {
 178                 global $wgExtensionDirectory;
 179                 $path = "$wgExtensionDirectory/$ext/extension.json";
 180         }
 181         ExtensionRegistry::getInstance()->queue( $path );
 182 }
 183
 184 /**
 185  * Load multiple extensions at once
 186  *
 187  * Same as wfLoadExtension, but more efficient if you
 188  * are loading multiple extensions.
 189  *
 190  * If you want to specify custom paths, you should interact with
 191  * ExtensionRegistry directly.
 192  *
 193  * @see wfLoadExtension
 194  * @param string[] $exts Array of extension names to load
 195  * @since 1.25
 196  */
 197 function wfLoadExtensions( array $exts ) {
 198         global $wgExtensionDirectory;
 199         $registry = ExtensionRegistry::getInstance();
 200         foreach ( $exts as $ext ) {
 201                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 202         }
 203 }
 204
 205 /**
 206  * Load a skin
 207  *
 208  * @see wfLoadExtension
 209  * @param string $skin Name of the extension to load
 210  * @param string|null $path Absolute path of where to find the skin.json file
 211  * @since 1.25
 212  */
 213 function wfLoadSkin( $skin, $path = null ) {
 214         if ( !$path ) {
 215                 global $wgStyleDirectory;
 216                 $path = "$wgStyleDirectory/$skin/skin.json";
 217         }
 218         ExtensionRegistry::getInstance()->queue( $path );
 219 }
 220
 221 /**
 222  * Load multiple skins at once
 223  *
 224  * @see wfLoadExtensions
 225  * @param string[] $skins Array of extension names to load
 226  * @since 1.25
 227  */
 228 function wfLoadSkins( array $skins ) {
 229         global $wgStyleDirectory;
 230         $registry = ExtensionRegistry::getInstance();
 231         foreach ( $skins as $skin ) {
 232                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 233         }
 234 }
 235
 236 /**
 237  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 238  * @param array $a
 239  * @param array $b
 240  * @return array
 241  */
 242 function wfArrayDiff2( $a, $b ) {
 243         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 244 }
 245
 246 /**
 247  * @param array|string $a
 248  * @param array|string $b
 249  * @return int
 250  */
 251 function wfArrayDiff2_cmp( $a, $b ) {
 252         if ( is_string( $a ) && is_string( $b ) ) {
 253                 return strcmp( $a, $b );
 254         } elseif ( count( $a ) !== count( $b ) ) {
 255                 return count( $a ) < count( $b ) ? -1 : 1;
 256         } else {
 257                 reset( $a );
 258                 reset( $b );
 259                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 260                         $cmp = strcmp( $valueA, $valueB );
 261                         if ( $cmp !== 0 ) {
 262                                 return $cmp;
 263                         }
 264                 }
 265                 return 0;
 266         }
 267 }
 268
 269 /**
 270  * Appends to second array if $value differs from that in $default
 271  *
 272  * @param string|int $key
 273  * @param mixed $value
 274  * @param mixed $default
 275  * @param array $changed Array to alter
 276  * @throws MWException
 277  */
 278 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 279         if ( is_null( $changed ) ) {
 280                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 281         }
 282         if ( $default[$key] !== $value ) {
 283                 $changed[$key] = $value;
 284         }
 285 }
 286
 287 /**
 288  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 289  * e.g.
 290  *      wfMergeErrorArrays(
 291  *              array( array( 'x' ) ),
 292  *              array( array( 'x', '2' ) ),
 293  *              array( array( 'x' ) ),
 294  *              array( array( 'y' ) )
 295  *      );
 296  * returns:
 297  *              array(
 298  *              array( 'x', '2' ),
 299  *              array( 'x' ),
 300  *              array( 'y' )
 301  *      )
 302  *
 303  * @param array $array1,...
 304  * @return array
 305  */
 306 function wfMergeErrorArrays( /*...*/ ) {
 307         $args = func_get_args();
 308         $out = array();
 309         foreach ( $args as $errors ) {
 310                 foreach ( $errors as $params ) {
 311                         $originalParams = $params;
 312                         if ( $params[0] instanceof MessageSpecifier ) {
 313                                 $msg = $params[0];
 314                                 $params = array_merge( array( $msg->getKey() ), $msg->getParams() );
 315                         }
 316                         # @todo FIXME: Sometimes get nested arrays for $params,
 317                         # which leads to E_NOTICEs
 318                         $spec = implode( "\t", $params );
 319                         $out[$spec] = $originalParams;
 320                 }
 321         }
 322         return array_values( $out );
 323 }
 324
 325 /**
 326  * Insert array into another array after the specified *KEY*
 327  *
 328  * @param array $array The array.
 329  * @param array $insert The array to insert.
 330  * @param mixed $after The key to insert after
 331  * @return array
 332  */
 333 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 334         // Find the offset of the element to insert after.
 335         $keys = array_keys( $array );
 336         $offsetByKey = array_flip( $keys );
 337
 338         $offset = $offsetByKey[$after];
 339
 340         // Insert at the specified offset
 341         $before = array_slice( $array, 0, $offset + 1, true );
 342         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 343
 344         $output = $before + $insert + $after;
 345
 346         return $output;
 347 }
 348
 349 /**
 350  * Recursively converts the parameter (an object) to an array with the same data
 351  *
 352  * @param object|array $objOrArray
 353  * @param bool $recursive
 354  * @return array
 355  */
 356 function wfObjectToArray( $objOrArray, $recursive = true ) {
 357         $array = array();
 358         if ( is_object( $objOrArray ) ) {
 359                 $objOrArray = get_object_vars( $objOrArray );
 360         }
 361         foreach ( $objOrArray as $key => $value ) {
 362                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 363                         $value = wfObjectToArray( $value );
 364                 }
 365
 366                 $array[$key] = $value;
 367         }
 368
 369         return $array;
 370 }
 371
 372 /**
 373  * Get a random decimal value between 0 and 1, in a way
 374  * not likely to give duplicate values for any realistic
 375  * number of articles.
 376  *
 377  * @return string
 378  */
 379 function wfRandom() {
 380         # The maximum random value is "only" 2^31-1, so get two random
 381         # values to reduce the chance of dupes
 382         $max = mt_getrandmax() + 1;
 383         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 384
 385         return $rand;
 386 }
 387
 388 /**
 389  * Get a random string containing a number of pseudo-random hex
 390  * characters.
 391  * @note This is not secure, if you are trying to generate some sort
 392  *       of token please use MWCryptRand instead.
 393  *
 394  * @param int $length The length of the string to generate
 395  * @return string
 396  * @since 1.20
 397  */
 398 function wfRandomString( $length = 32 ) {
 399         $str = '';
 400         for ( $n = 0; $n < $length; $n += 7 ) {
 401                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 402         }
 403         return substr( $str, 0, $length );
 404 }
 405
 406 /**
 407  * We want some things to be included as literal characters in our title URLs
 408  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 409  * all of the following should be safe:
 410  *
 411  * ;:@&=$-_.+!*'(),
 412  *
 413  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 414  * character which should not be encoded. More importantly, google chrome
 415  * always converts %7E back to ~, and converting it in this function can
 416  * cause a redirect loop (T105265).
 417  *
 418  * But + is not safe because it's used to indicate a space; &= are only safe in
 419  * paths and not in queries (and we don't distinguish here); ' seems kind of
 420  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 421  * is reserved, we don't care.  So the list we unescape is:
 422  *
 423  * ;:@$!*(),/~
 424  *
 425  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 426  * so no fancy : for IIS7.
 427  *
 428  * %2F in the page titles seems to fatally break for some reason.
 429  *
 430  * @param string $s
 431  * @return string
 432  */
 433 function wfUrlencode( $s ) {
 434         static $needle;
 435
 436         if ( is_null( $s ) ) {
 437                 $needle = null;
 438                 return '';
 439         }
 440
 441         if ( is_null( $needle ) ) {
 442                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' );
 443                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 444                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 445                 ) {
 446                         $needle[] = '%3A';
 447                 }
 448         }
 449
 450         $s = urlencode( $s );
 451         $s = str_ireplace(
 452                 $needle,
 453                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ),
 454                 $s
 455         );
 456
 457         return $s;
 458 }
 459
 460 /**
 461  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 462  * "days=7&limit=100". Options in the first array override options in the second.
 463  * Options set to null or false will not be output.
 464  *
 465  * @param array $array1 ( String|Array )
 466  * @param array $array2 ( String|Array )
 467  * @param string $prefix
 468  * @return string
 469  */
 470 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 471         if ( !is_null( $array2 ) ) {
 472                 $array1 = $array1 + $array2;
 473         }
 474
 475         $cgi = '';
 476         foreach ( $array1 as $key => $value ) {
 477                 if ( !is_null( $value ) && $value !== false ) {
 478                         if ( $cgi != '' ) {
 479                                 $cgi .= '&';
 480                         }
 481                         if ( $prefix !== '' ) {
 482                                 $key = $prefix . "[$key]";
 483                         }
 484                         if ( is_array( $value ) ) {
 485                                 $firstTime = true;
 486                                 foreach ( $value as $k => $v ) {
 487                                         $cgi .= $firstTime ? '' : '&';
 488                                         if ( is_array( $v ) ) {
 489                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 490                                         } else {
 491                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 492                                         }
 493                                         $firstTime = false;
 494                                 }
 495                         } else {
 496                                 if ( is_object( $value ) ) {
 497                                         $value = $value->__toString();
 498                                 }
 499                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 500                         }
 501                 }
 502         }
 503         return $cgi;
 504 }
 505
 506 /**
 507  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 508  * its argument and returns the same string in array form.  This allows compatibility
 509  * with legacy functions that accept raw query strings instead of nice
 510  * arrays.  Of course, keys and values are urldecode()d.
 511  *
 512  * @param string $query Query string
 513  * @return string[] Array version of input
 514  */
 515 function wfCgiToArray( $query ) {
 516         if ( isset( $query[0] ) && $query[0] == '?' ) {
 517                 $query = substr( $query, 1 );
 518         }
 519         $bits = explode( '&', $query );
 520         $ret = array();
 521         foreach ( $bits as $bit ) {
 522                 if ( $bit === '' ) {
 523                         continue;
 524                 }
 525                 if ( strpos( $bit, '=' ) === false ) {
 526                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 527                         $key = $bit;
 528                         $value = '';
 529                 } else {
 530                         list( $key, $value ) = explode( '=', $bit );
 531                 }
 532                 $key = urldecode( $key );
 533                 $value = urldecode( $value );
 534                 if ( strpos( $key, '[' ) !== false ) {
 535                         $keys = array_reverse( explode( '[', $key ) );
 536                         $key = array_pop( $keys );
 537                         $temp = $value;
 538                         foreach ( $keys as $k ) {
 539                                 $k = substr( $k, 0, -1 );
 540                                 $temp = array( $k => $temp );
 541                         }
 542                         if ( isset( $ret[$key] ) ) {
 543                                 $ret[$key] = array_merge( $ret[$key], $temp );
 544                         } else {
 545                                 $ret[$key] = $temp;
 546                         }
 547                 } else {
 548                         $ret[$key] = $value;
 549                 }
 550         }
 551         return $ret;
 552 }
 553
 554 /**
 555  * Append a query string to an existing URL, which may or may not already
 556  * have query string parameters already. If so, they will be combined.
 557  *
 558  * @param string $url
 559  * @param string|string[] $query String or associative array
 560  * @return string
 561  */
 562 function wfAppendQuery( $url, $query ) {
 563         if ( is_array( $query ) ) {
 564                 $query = wfArrayToCgi( $query );
 565         }
 566         if ( $query != '' ) {
 567                 if ( false === strpos( $url, '?' ) ) {
 568                         $url .= '?';
 569                 } else {
 570                         $url .= '&';
 571                 }
 572                 $url .= $query;
 573         }
 574         return $url;
 575 }
 576
 577 /**
 578  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 579  * is correct.
 580  *
 581  * The meaning of the PROTO_* constants is as follows:
 582  * PROTO_HTTP: Output a URL starting with http://
 583  * PROTO_HTTPS: Output a URL starting with https://
 584  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 585  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 586  *    on which protocol was used for the current incoming request
 587  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 588  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 589  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 590  *
 591  * @todo this won't work with current-path-relative URLs
 592  * like "subdir/foo.html", etc.
 593  *
 594  * @param string $url Either fully-qualified or a local path + query
 595  * @param string $defaultProto One of the PROTO_* constants. Determines the
 596  *    protocol to use if $url or $wgServer is protocol-relative
 597  * @return string Fully-qualified URL, current-path-relative URL or false if
 598  *    no valid URL can be constructed
 599  */
 600 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 601         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 602                 $wgHttpsPort;
 603         if ( $defaultProto === PROTO_CANONICAL ) {
 604                 $serverUrl = $wgCanonicalServer;
 605         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 606                 // Make $wgInternalServer fall back to $wgServer if not set
 607                 $serverUrl = $wgInternalServer;
 608         } else {
 609                 $serverUrl = $wgServer;
 610                 if ( $defaultProto === PROTO_CURRENT ) {
 611                         $defaultProto = $wgRequest->getProtocol() . '://';
 612                 }
 613         }
 614
 615         // Analyze $serverUrl to obtain its protocol
 616         $bits = wfParseUrl( $serverUrl );
 617         $serverHasProto = $bits && $bits['scheme'] != '';
 618
 619         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 620                 if ( $serverHasProto ) {
 621                         $defaultProto = $bits['scheme'] . '://';
 622                 } else {
 623                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 624                         // This really isn't supposed to happen. Fall back to HTTP in this
 625                         // ridiculous case.
 626                         $defaultProto = PROTO_HTTP;
 627                 }
 628         }
 629
 630         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 631
 632         if ( substr( $url, 0, 2 ) == '//' ) {
 633                 $url = $defaultProtoWithoutSlashes . $url;
 634         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 635                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 636                 // otherwise leave it alone.
 637                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 638         }
 639
 640         $bits = wfParseUrl( $url );
 641
 642         // ensure proper port for HTTPS arrives in URL
 643         // https://phabricator.wikimedia.org/T67184
 644         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 645                 $bits['port'] = $wgHttpsPort;
 646         }
 647
 648         if ( $bits && isset( $bits['path'] ) ) {
 649                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 650                 return wfAssembleUrl( $bits );
 651         } elseif ( $bits ) {
 652                 # No path to expand
 653                 return $url;
 654         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 655                 # URL is a relative path
 656                 return wfRemoveDotSegments( $url );
 657         }
 658
 659         # Expanded URL is not valid.
 660         return false;
 661 }
 662
 663 /**
 664  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 665  * if you need to edit part of a URL and put it back together.
 666  *
 667  * This is the basic structure used (brackets contain keys for $urlParts):
 668  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 669  *
 670  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 671  *
 672  * @since 1.19
 673  * @param array $urlParts URL parts, as output from wfParseUrl
 674  * @return string URL assembled from its component parts
 675  */
 676 function wfAssembleUrl( $urlParts ) {
 677         $result = '';
 678
 679         if ( isset( $urlParts['delimiter'] ) ) {
 680                 if ( isset( $urlParts['scheme'] ) ) {
 681                         $result .= $urlParts['scheme'];
 682                 }
 683
 684                 $result .= $urlParts['delimiter'];
 685         }
 686
 687         if ( isset( $urlParts['host'] ) ) {
 688                 if ( isset( $urlParts['user'] ) ) {
 689                         $result .= $urlParts['user'];
 690                         if ( isset( $urlParts['pass'] ) ) {
 691                                 $result .= ':' . $urlParts['pass'];
 692                         }
 693                         $result .= '@';
 694                 }
 695
 696                 $result .= $urlParts['host'];
 697
 698                 if ( isset( $urlParts['port'] ) ) {
 699                         $result .= ':' . $urlParts['port'];
 700                 }
 701         }
 702
 703         if ( isset( $urlParts['path'] ) ) {
 704                 $result .= $urlParts['path'];
 705         }
 706
 707         if ( isset( $urlParts['query'] ) ) {
 708                 $result .= '?' . $urlParts['query'];
 709         }
 710
 711         if ( isset( $urlParts['fragment'] ) ) {
 712                 $result .= '#' . $urlParts['fragment'];
 713         }
 714
 715         return $result;
 716 }
 717
 718 /**
 719  * Remove all dot-segments in the provided URL path.  For example,
 720  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 721  * RFC3986 section 5.2.4.
 722  *
 723  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 724  *
 725  * @param string $urlPath URL path, potentially containing dot-segments
 726  * @return string URL path with all dot-segments removed
 727  */
 728 function wfRemoveDotSegments( $urlPath ) {
 729         $output = '';
 730         $inputOffset = 0;
 731         $inputLength = strlen( $urlPath );
 732
 733         while ( $inputOffset < $inputLength ) {
 734                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 735                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 736                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 737                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 738                 $trimOutput = false;
 739
 740                 if ( $prefixLengthTwo == './' ) {
 741                         # Step A, remove leading "./"
 742                         $inputOffset += 2;
 743                 } elseif ( $prefixLengthThree == '../' ) {
 744                         # Step A, remove leading "../"
 745                         $inputOffset += 3;
 746                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 747                         # Step B, replace leading "/.$" with "/"
 748                         $inputOffset += 1;
 749                         $urlPath[$inputOffset] = '/';
 750                 } elseif ( $prefixLengthThree == '/./' ) {
 751                         # Step B, replace leading "/./" with "/"
 752                         $inputOffset += 2;
 753                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 754                         # Step C, replace leading "/..$" with "/" and
 755                         # remove last path component in output
 756                         $inputOffset += 2;
 757                         $urlPath[$inputOffset] = '/';
 758                         $trimOutput = true;
 759                 } elseif ( $prefixLengthFour == '/../' ) {
 760                         # Step C, replace leading "/../" with "/" and
 761                         # remove last path component in output
 762                         $inputOffset += 3;
 763                         $trimOutput = true;
 764                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 765                         # Step D, remove "^.$"
 766                         $inputOffset += 1;
 767                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 768                         # Step D, remove "^..$"
 769                         $inputOffset += 2;
 770                 } else {
 771                         # Step E, move leading path segment to output
 772                         if ( $prefixLengthOne == '/' ) {
 773                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 774                         } else {
 775                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 776                         }
 777                         if ( $slashPos === false ) {
 778                                 $output .= substr( $urlPath, $inputOffset );
 779                                 $inputOffset = $inputLength;
 780                         } else {
 781                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 782                                 $inputOffset += $slashPos - $inputOffset;
 783                         }
 784                 }
 785
 786                 if ( $trimOutput ) {
 787                         $slashPos = strrpos( $output, '/' );
 788                         if ( $slashPos === false ) {
 789                                 $output = '';
 790                         } else {
 791                                 $output = substr( $output, 0, $slashPos );
 792                         }
 793                 }
 794         }
 795
 796         return $output;
 797 }
 798
 799 /**
 800  * Returns a regular expression of url protocols
 801  *
 802  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 803  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 804  * @return string
 805  */
 806 function wfUrlProtocols( $includeProtocolRelative = true ) {
 807         global $wgUrlProtocols;
 808
 809         // Cache return values separately based on $includeProtocolRelative
 810         static $withProtRel = null, $withoutProtRel = null;
 811         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 812         if ( !is_null( $cachedValue ) ) {
 813                 return $cachedValue;
 814         }
 815
 816         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 817         // with LocalSettings files from 1.5
 818         if ( is_array( $wgUrlProtocols ) ) {
 819                 $protocols = array();
 820                 foreach ( $wgUrlProtocols as $protocol ) {
 821                         // Filter out '//' if !$includeProtocolRelative
 822                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 823                                 $protocols[] = preg_quote( $protocol, '/' );
 824                         }
 825                 }
 826
 827                 $retval = implode( '|', $protocols );
 828         } else {
 829                 // Ignore $includeProtocolRelative in this case
 830                 // This case exists for pre-1.6 compatibility, and we can safely assume
 831                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 832                 // URLs weren't supported until 1.18
 833                 $retval = $wgUrlProtocols;
 834         }
 835
 836         // Cache return value
 837         if ( $includeProtocolRelative ) {
 838                 $withProtRel = $retval;
 839         } else {
 840                 $withoutProtRel = $retval;
 841         }
 842         return $retval;
 843 }
 844
 845 /**
 846  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 847  * you need a regex that matches all URL protocols but does not match protocol-
 848  * relative URLs
 849  * @return string
 850  */
 851 function wfUrlProtocolsWithoutProtRel() {
 852         return wfUrlProtocols( false );
 853 }
 854
 855 /**
 856  * parse_url() work-alike, but non-broken.  Differences:
 857  *
 858  * 1) Does not raise warnings on bad URLs (just returns false).
 859  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 860  *    protocol-relative URLs) correctly.
 861  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 862  *
 863  * @param string $url A URL to parse
 864  * @return string[] Bits of the URL in an associative array, per PHP docs
 865  */
 866 function wfParseUrl( $url ) {
 867         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 868
 869         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 870         // bad that the easiest way to handle them is to just prepend 'http:' and
 871         // strip the protocol out later.
 872         $wasRelative = substr( $url, 0, 2 ) == '//';
 873         if ( $wasRelative ) {
 874                 $url = "http:$url";
 875         }
 876         MediaWiki\suppressWarnings();
 877         $bits = parse_url( $url );
 878         MediaWiki\restoreWarnings();
 879         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 880         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 881         if ( !$bits || !isset( $bits['scheme'] ) ) {
 882                 return false;
 883         }
 884
 885         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 886         $bits['scheme'] = strtolower( $bits['scheme'] );
 887
 888         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 889         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 890                 $bits['delimiter'] = '://';
 891         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 892                 $bits['delimiter'] = ':';
 893                 // parse_url detects for news: and mailto: the host part of an url as path
 894                 // We have to correct this wrong detection
 895                 if ( isset( $bits['path'] ) ) {
 896                         $bits['host'] = $bits['path'];
 897                         $bits['path'] = '';
 898                 }
 899         } else {
 900                 return false;
 901         }
 902
 903         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 904         if ( !isset( $bits['host'] ) ) {
 905                 $bits['host'] = '';
 906
 907                 // bug 45069
 908                 if ( isset( $bits['path'] ) ) {
 909                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 910                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 911                                 $bits['path'] = '/' . $bits['path'];
 912                         }
 913                 } else {
 914                         $bits['path'] = '';
 915                 }
 916         }
 917
 918         // If the URL was protocol-relative, fix scheme and delimiter
 919         if ( $wasRelative ) {
 920                 $bits['scheme'] = '';
 921                 $bits['delimiter'] = '//';
 922         }
 923         return $bits;
 924 }
 925
 926 /**
 927  * Take a URL, make sure it's expanded to fully qualified, and replace any
 928  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 929  * for more compact display and legibility for local audiences.
 930  *
 931  * @todo handle punycode domains too
 932  *
 933  * @param string $url
 934  * @return string
 935  */
 936 function wfExpandIRI( $url ) {
 937         return preg_replace_callback(
 938                 '/((?:%[89A-F][0-9A-F])+)/i',
 939                 'wfExpandIRI_callback',
 940                 wfExpandUrl( $url )
 941         );
 942 }
 943
 944 /**
 945  * Private callback for wfExpandIRI
 946  * @param array $matches
 947  * @return string
 948  */
 949 function wfExpandIRI_callback( $matches ) {
 950         return urldecode( $matches[1] );
 951 }
 952
 953 /**
 954  * Make URL indexes, appropriate for the el_index field of externallinks.
 955  *
 956  * @param string $url
 957  * @return array
 958  */
 959 function wfMakeUrlIndexes( $url ) {
 960         $bits = wfParseUrl( $url );
 961
 962         // Reverse the labels in the hostname, convert to lower case
 963         // For emails reverse domainpart only
 964         if ( $bits['scheme'] == 'mailto' ) {
 965                 $mailparts = explode( '@', $bits['host'], 2 );
 966                 if ( count( $mailparts ) === 2 ) {
 967                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 968                 } else {
 969                         // No domain specified, don't mangle it
 970                         $domainpart = '';
 971                 }
 972                 $reversedHost = $domainpart . '@' . $mailparts[0];
 973         } else {
 974                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 975         }
 976         // Add an extra dot to the end
 977         // Why? Is it in wrong place in mailto links?
 978         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 979                 $reversedHost .= '.';
 980         }
 981         // Reconstruct the pseudo-URL
 982         $prot = $bits['scheme'];
 983         $index = $prot . $bits['delimiter'] . $reversedHost;
 984         // Leave out user and password. Add the port, path, query and fragment
 985         if ( isset( $bits['port'] ) ) {
 986                 $index .= ':' . $bits['port'];
 987         }
 988         if ( isset( $bits['path'] ) ) {
 989                 $index .= $bits['path'];
 990         } else {
 991                 $index .= '/';
 992         }
 993         if ( isset( $bits['query'] ) ) {
 994                 $index .= '?' . $bits['query'];
 995         }
 996         if ( isset( $bits['fragment'] ) ) {
 997                 $index .= '#' . $bits['fragment'];
 998         }
 999
1000         if ( $prot == '' ) {
1001                 return array( "http:$index", "https:$index" );
1002         } else {
1003                 return array( $index );
1004         }
1005 }
1006
1007 /**
1008  * Check whether a given URL has a domain that occurs in a given set of domains
1009  * @param string $url URL
1010  * @param array $domains Array of domains (strings)
1011  * @return bool True if the host part of $url ends in one of the strings in $domains
1012  */
1013 function wfMatchesDomainList( $url, $domains ) {
1014         $bits = wfParseUrl( $url );
1015         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1016                 $host = '.' . $bits['host'];
1017                 foreach ( (array)$domains as $domain ) {
1018                         $domain = '.' . $domain;
1019                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1020                                 return true;
1021                         }
1022                 }
1023         }
1024         return false;
1025 }
1026
1027 /**
1028  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1029  * In normal operation this is a NOP.
1030  *
1031  * Controlling globals:
1032  * $wgDebugLogFile - points to the log file
1033  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1034  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1035  *
1036  * @since 1.25 support for additional context data
1037  *
1038  * @param string $text
1039  * @param string|bool $dest Unused
1040  * @param array $context Additional logging context data
1041  */
1042 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1043         global $wgDebugRawPage, $wgDebugLogPrefix;
1044         global $wgDebugTimestamps, $wgRequestTime;
1045
1046         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1047                 return;
1048         }
1049
1050         $text = trim( $text );
1051
1052         // Inline logic from deprecated wfDebugTimer()
1053         if ( $wgDebugTimestamps ) {
1054                 $context['seconds_elapsed'] = sprintf(
1055                         '%6.4f',
1056                         microtime( true ) - $wgRequestTime
1057                 );
1058                 $context['memory_used'] = sprintf(
1059                         '%5.1fM',
1060                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1061                 );
1062         }
1063
1064         if ( $wgDebugLogPrefix !== '' ) {
1065                 $context['prefix'] = $wgDebugLogPrefix;
1066         }
1067
1068         $logger = LoggerFactory::getInstance( 'wfDebug' );
1069         $logger->debug( $text, $context );
1070 }
1071
1072 /**
1073  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1074  * @return bool
1075  */
1076 function wfIsDebugRawPage() {
1077         static $cache;
1078         if ( $cache !== null ) {
1079                 return $cache;
1080         }
1081         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1082         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1083                 || (
1084                         isset( $_SERVER['SCRIPT_NAME'] )
1085                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1086                 )
1087         ) {
1088                 $cache = true;
1089         } else {
1090                 $cache = false;
1091         }
1092         return $cache;
1093 }
1094
1095 /**
1096  * Get microsecond timestamps for debug logs
1097  *
1098  * @deprecated since 1.25
1099  * @return string
1100  */
1101 function wfDebugTimer() {
1102         global $wgDebugTimestamps, $wgRequestTime;
1103
1104         wfDeprecated( __METHOD__, '1.25' );
1105
1106         if ( !$wgDebugTimestamps ) {
1107                 return '';
1108         }
1109
1110         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1111         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1112         return "$prefix $mem  ";
1113 }
1114
1115 /**
1116  * Send a line giving PHP memory usage.
1117  *
1118  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1119  */
1120 function wfDebugMem( $exact = false ) {
1121         $mem = memory_get_usage();
1122         if ( !$exact ) {
1123                 $mem = floor( $mem / 1024 ) . ' KiB';
1124         } else {
1125                 $mem .= ' B';
1126         }
1127         wfDebug( "Memory usage: $mem\n" );
1128 }
1129
1130 /**
1131  * Send a line to a supplementary debug log file, if configured, or main debug
1132  * log if not.
1133  *
1134  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1135  * a string filename or an associative array mapping 'destination' to the
1136  * desired filename. The associative array may also contain a 'sample' key
1137  * with an integer value, specifying a sampling factor. Sampled log events
1138  * will be emitted with a 1 in N random chance.
1139  *
1140  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1141  * @since 1.25 support for additional context data
1142  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1143  *
1144  * @param string $logGroup
1145  * @param string $text
1146  * @param string|bool $dest Destination of the message:
1147  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1148  *     - 'log': only to the log and not in HTML
1149  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1150  *       discarded otherwise
1151  *   For backward compatibility, it can also take a boolean:
1152  *     - true: same as 'all'
1153  *     - false: same as 'private'
1154  * @param array $context Additional logging context data
1155  */
1156 function wfDebugLog(
1157         $logGroup, $text, $dest = 'all', array $context = array()
1158 ) {
1159         // Turn $dest into a string if it's a boolean (for b/c)
1160         if ( $dest === true ) {
1161                 $dest = 'all';
1162         } elseif ( $dest === false ) {
1163                 $dest = 'private';
1164         }
1165
1166         $text = trim( $text );
1167
1168         $logger = LoggerFactory::getInstance( $logGroup );
1169         $context['private'] = ( $dest === 'private' );
1170         $logger->info( $text, $context );
1171 }
1172
1173 /**
1174  * Log for database errors
1175  *
1176  * @since 1.25 support for additional context data
1177  *
1178  * @param string $text Database error message.
1179  * @param array $context Additional logging context data
1180  */
1181 function wfLogDBError( $text, array $context = array() ) {
1182         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1183         $logger->error( trim( $text ), $context );
1184 }
1185
1186 /**
1187  * Throws a warning that $function is deprecated
1188  *
1189  * @param string $function
1190  * @param string|bool $version Version of MediaWiki that the function
1191  *    was deprecated in (Added in 1.19).
1192  * @param string|bool $component Added in 1.19.
1193  * @param int $callerOffset How far up the call stack is the original
1194  *    caller. 2 = function that called the function that called
1195  *    wfDeprecated (Added in 1.20)
1196  *
1197  * @return null
1198  */
1199 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1200         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1201 }
1202
1203 /**
1204  * Send a warning either to the debug log or in a PHP error depending on
1205  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1206  *
1207  * @param string $msg Message to send
1208  * @param int $callerOffset Number of items to go back in the backtrace to
1209  *        find the correct caller (1 = function calling wfWarn, ...)
1210  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1211  *        only used when $wgDevelopmentWarnings is true
1212  */
1213 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1214         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1215 }
1216
1217 /**
1218  * Send a warning as a PHP error and the debug log. This is intended for logging
1219  * warnings in production. For logging development warnings, use WfWarn instead.
1220  *
1221  * @param string $msg Message to send
1222  * @param int $callerOffset Number of items to go back in the backtrace to
1223  *        find the correct caller (1 = function calling wfLogWarning, ...)
1224  * @param int $level PHP error level; defaults to E_USER_WARNING
1225  */
1226 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1227         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1228 }
1229
1230 /**
1231  * Log to a file without getting "file size exceeded" signals.
1232  *
1233  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1234  * send lines to the specified port, prefixed by the specified prefix and a space.
1235  * @since 1.25 support for additional context data
1236  *
1237  * @param string $text
1238  * @param string $file Filename
1239  * @param array $context Additional logging context data
1240  * @throws MWException
1241  * @deprecated since 1.25 Use \\MediaWiki\\Logger\\LegacyLogger::emit or UDPTransport
1242  */
1243 function wfErrorLog( $text, $file, array $context = array() ) {
1244         wfDeprecated( __METHOD__, '1.25' );
1245         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1246         $context['destination'] = $file;
1247         $logger->info( trim( $text ), $context );
1248 }
1249
1250 /**
1251  * @todo document
1252  */
1253 function wfLogProfilingData() {
1254         global $wgDebugLogGroups, $wgDebugRawPage;
1255
1256         $context = RequestContext::getMain();
1257         $request = $context->getRequest();
1258
1259         $profiler = Profiler::instance();
1260         $profiler->setContext( $context );
1261         $profiler->logData();
1262
1263         $config = $context->getConfig();
1264         if ( $config->get( 'StatsdServer' ) ) {
1265                 try {
1266                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1267                         $statsdHost = $statsdServer[0];
1268                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1269                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1270                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1271                         $statsdClient->send( $context->getStats()->getBuffer() );
1272                 } catch ( Exception $ex ) {
1273                         MWExceptionHandler::logException( $ex );
1274                 }
1275         }
1276
1277         # Profiling must actually be enabled...
1278         if ( $profiler instanceof ProfilerStub ) {
1279                 return;
1280         }
1281
1282         if ( isset( $wgDebugLogGroups['profileoutput'] )
1283                 && $wgDebugLogGroups['profileoutput'] === false
1284         ) {
1285                 // Explicitly disabled
1286                 return;
1287         }
1288         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1289                 return;
1290         }
1291
1292         $ctx = array( 'elapsed' => $request->getElapsedTime() );
1293         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1294                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1295         }
1296         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1297                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1298         }
1299         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1300                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1301         }
1302         if ( isset( $ctx['forwarded_for'] ) ||
1303                 isset( $ctx['client_ip'] ) ||
1304                 isset( $ctx['from'] ) ) {
1305                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1306         }
1307
1308         // Don't load $wgUser at this late stage just for statistics purposes
1309         // @todo FIXME: We can detect some anons even if it is not loaded.
1310         // See User::getId()
1311         $user = $context->getUser();
1312         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1313
1314         // Command line script uses a FauxRequest object which does not have
1315         // any knowledge about an URL and throw an exception instead.
1316         try {
1317                 $ctx['url'] = urldecode( $request->getRequestURL() );
1318         } catch ( Exception $ignored ) {
1319                 // no-op
1320         }
1321
1322         $ctx['output'] = $profiler->getOutput();
1323
1324         $log = LoggerFactory::getInstance( 'profileoutput' );
1325         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1326 }
1327
1328 /**
1329  * Increment a statistics counter
1330  *
1331  * @param string $key
1332  * @param int $count
1333  * @return void
1334  */
1335 function wfIncrStats( $key, $count = 1 ) {
1336         $stats = RequestContext::getMain()->getStats();
1337         $stats->updateCount( $key, $count );
1338 }
1339
1340 /**
1341  * Check whether the wiki is in read-only mode.
1342  *
1343  * @return bool
1344  */
1345 function wfReadOnly() {
1346         return wfReadOnlyReason() !== false;
1347 }
1348
1349 /**
1350  * Check if the site is in read-only mode and return the message if so
1351  *
1352  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1353  * for slave lag. This may result in DB_SLAVE connection being made.
1354  *
1355  * @return string|bool String when in read-only mode; false otherwise
1356  */
1357 function wfReadOnlyReason() {
1358         $readOnly = wfConfiguredReadOnlyReason();
1359         if ( $readOnly !== false ) {
1360                 return $readOnly;
1361         }
1362
1363         static $lbReadOnly = null;
1364         if ( $lbReadOnly === null ) {
1365                 // Callers use this method to be aware that data presented to a user
1366                 // may be very stale and thus allowing submissions can be problematic.
1367                 $lbReadOnly = wfGetLB()->getReadOnlyReason();
1368         }
1369
1370         return $lbReadOnly;
1371 }
1372
1373 /**
1374  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1375  *
1376  * @return string|bool String when in read-only mode; false otherwise
1377  * @since 1.27
1378  */
1379 function wfConfiguredReadOnlyReason() {
1380         global $wgReadOnly, $wgReadOnlyFile;
1381
1382         if ( $wgReadOnly === null ) {
1383                 // Set $wgReadOnly for faster access next time
1384                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1385                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1386                 } else {
1387                         $wgReadOnly = false;
1388                 }
1389         }
1390
1391         return $wgReadOnly;
1392 }
1393
1394 /**
1395  * Return a Language object from $langcode
1396  *
1397  * @param Language|string|bool $langcode Either:
1398  *                  - a Language object
1399  *                  - code of the language to get the message for, if it is
1400  *                    a valid code create a language for that language, if
1401  *                    it is a string but not a valid code then make a basic
1402  *                    language object
1403  *                  - a boolean: if it's false then use the global object for
1404  *                    the current user's language (as a fallback for the old parameter
1405  *                    functionality), or if it is true then use global object
1406  *                    for the wiki's content language.
1407  * @return Language
1408  */
1409 function wfGetLangObj( $langcode = false ) {
1410         # Identify which language to get or create a language object for.
1411         # Using is_object here due to Stub objects.
1412         if ( is_object( $langcode ) ) {
1413                 # Great, we already have the object (hopefully)!
1414                 return $langcode;
1415         }
1416
1417         global $wgContLang, $wgLanguageCode;
1418         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1419                 # $langcode is the language code of the wikis content language object.
1420                 # or it is a boolean and value is true
1421                 return $wgContLang;
1422         }
1423
1424         global $wgLang;
1425         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1426                 # $langcode is the language code of user language object.
1427                 # or it was a boolean and value is false
1428                 return $wgLang;
1429         }
1430
1431         $validCodes = array_keys( Language::fetchLanguageNames() );
1432         if ( in_array( $langcode, $validCodes ) ) {
1433                 # $langcode corresponds to a valid language.
1434                 return Language::factory( $langcode );
1435         }
1436
1437         # $langcode is a string, but not a valid language code; use content language.
1438         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1439         return $wgContLang;
1440 }
1441
1442 /**
1443  * This is the function for getting translated interface messages.
1444  *
1445  * @see Message class for documentation how to use them.
1446  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1447  *
1448  * This function replaces all old wfMsg* functions.
1449  *
1450  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1451  * @param mixed $params,... Normal message parameters
1452  * @return Message
1453  *
1454  * @since 1.17
1455  *
1456  * @see Message::__construct
1457  */
1458 function wfMessage( $key /*...*/ ) {
1459         $params = func_get_args();
1460         array_shift( $params );
1461         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1462                 $params = $params[0];
1463         }
1464         return new Message( $key, $params );
1465 }
1466
1467 /**
1468  * This function accepts multiple message keys and returns a message instance
1469  * for the first message which is non-empty. If all messages are empty then an
1470  * instance of the first message key is returned.
1471  *
1472  * @param string|string[] $keys,... Message keys
1473  * @return Message
1474  *
1475  * @since 1.18
1476  *
1477  * @see Message::newFallbackSequence
1478  */
1479 function wfMessageFallback( /*...*/ ) {
1480         $args = func_get_args();
1481         return call_user_func_array( 'Message::newFallbackSequence', $args );
1482 }
1483
1484 /**
1485  * Get a message from anywhere, for the current user language.
1486  *
1487  * Use wfMsgForContent() instead if the message should NOT
1488  * change depending on the user preferences.
1489  *
1490  * @deprecated since 1.18
1491  *
1492  * @param string $key Lookup key for the message, usually
1493  *    defined in languages/Language.php
1494  *
1495  * Parameters to the message, which can be used to insert variable text into
1496  * it, can be passed to this function in the following formats:
1497  * - One per argument, starting at the second parameter
1498  * - As an array in the second parameter
1499  * These are not shown in the function definition.
1500  *
1501  * @return string
1502  */
1503 function wfMsg( $key ) {
1504         wfDeprecated( __METHOD__, '1.21' );
1505
1506         $args = func_get_args();
1507         array_shift( $args );
1508         return wfMsgReal( $key, $args );
1509 }
1510
1511 /**
1512  * Same as above except doesn't transform the message
1513  *
1514  * @deprecated since 1.18
1515  *
1516  * @param string $key
1517  * @return string
1518  */
1519 function wfMsgNoTrans( $key ) {
1520         wfDeprecated( __METHOD__, '1.21' );
1521
1522         $args = func_get_args();
1523         array_shift( $args );
1524         return wfMsgReal( $key, $args, true, false, false );
1525 }
1526
1527 /**
1528  * Get a message from anywhere, for the current global language
1529  * set with $wgLanguageCode.
1530  *
1531  * Use this if the message should NOT change dependent on the
1532  * language set in the user's preferences. This is the case for
1533  * most text written into logs, as well as link targets (such as
1534  * the name of the copyright policy page). Link titles, on the
1535  * other hand, should be shown in the UI language.
1536  *
1537  * Note that MediaWiki allows users to change the user interface
1538  * language in their preferences, but a single installation
1539  * typically only contains content in one language.
1540  *
1541  * Be wary of this distinction: If you use wfMsg() where you should
1542  * use wfMsgForContent(), a user of the software may have to
1543  * customize potentially hundreds of messages in
1544  * order to, e.g., fix a link in every possible language.
1545  *
1546  * @deprecated since 1.18
1547  *
1548  * @param string $key Lookup key for the message, usually
1549  *     defined in languages/Language.php
1550  * @return string
1551  */
1552 function wfMsgForContent( $key ) {
1553         wfDeprecated( __METHOD__, '1.21' );
1554
1555         global $wgForceUIMsgAsContentMsg;
1556         $args = func_get_args();
1557         array_shift( $args );
1558         $forcontent = true;
1559         if ( is_array( $wgForceUIMsgAsContentMsg )
1560                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1561         ) {
1562                 $forcontent = false;
1563         }
1564         return wfMsgReal( $key, $args, true, $forcontent );
1565 }
1566
1567 /**
1568  * Same as above except doesn't transform the message
1569  *
1570  * @deprecated since 1.18
1571  *
1572  * @param string $key
1573  * @return string
1574  */
1575 function wfMsgForContentNoTrans( $key ) {
1576         wfDeprecated( __METHOD__, '1.21' );
1577
1578         global $wgForceUIMsgAsContentMsg;
1579         $args = func_get_args();
1580         array_shift( $args );
1581         $forcontent = true;
1582         if ( is_array( $wgForceUIMsgAsContentMsg )
1583                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1584         ) {
1585                 $forcontent = false;
1586         }
1587         return wfMsgReal( $key, $args, true, $forcontent, false );
1588 }
1589
1590 /**
1591  * Really get a message
1592  *
1593  * @deprecated since 1.18
1594  *
1595  * @param string $key Key to get.
1596  * @param array $args
1597  * @param bool $useDB
1598  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1599  * @param bool $transform Whether or not to transform the message.
1600  * @return string The requested message.
1601  */
1602 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1603         wfDeprecated( __METHOD__, '1.21' );
1604
1605         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1606         $message = wfMsgReplaceArgs( $message, $args );
1607         return $message;
1608 }
1609
1610 /**
1611  * Fetch a message string value, but don't replace any keys yet.
1612  *
1613  * @deprecated since 1.18
1614  *
1615  * @param string $key
1616  * @param bool $useDB
1617  * @param string|bool $langCode Code of the language to get the message for, or
1618  *   behaves as a content language switch if it is a boolean.
1619  * @param bool $transform Whether to parse magic words, etc.
1620  * @return string
1621  */
1622 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1623         wfDeprecated( __METHOD__, '1.21' );
1624
1625         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1626
1627         $cache = MessageCache::singleton();
1628         $message = $cache->get( $key, $useDB, $langCode );
1629         if ( $message === false ) {
1630                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1631         } elseif ( $transform ) {
1632                 $message = $cache->transform( $message );
1633         }
1634         return $message;
1635 }
1636
1637 /**
1638  * Replace message parameter keys on the given formatted output.
1639  *
1640  * @param string $message
1641  * @param array $args
1642  * @return string
1643  * @private
1644  */
1645 function wfMsgReplaceArgs( $message, $args ) {
1646         # Fix windows line-endings
1647         # Some messages are split with explode("\n", $msg)
1648         $message = str_replace( "\r", '', $message );
1649
1650         // Replace arguments
1651         if ( count( $args ) ) {
1652                 if ( is_array( $args[0] ) ) {
1653                         $args = array_values( $args[0] );
1654                 }
1655                 $replacementKeys = array();
1656                 foreach ( $args as $n => $param ) {
1657                         $replacementKeys['$' . ( $n + 1 )] = $param;
1658                 }
1659                 $message = strtr( $message, $replacementKeys );
1660         }
1661
1662         return $message;
1663 }
1664
1665 /**
1666  * Return an HTML-escaped version of a message.
1667  * Parameter replacements, if any, are done *after* the HTML-escaping,
1668  * so parameters may contain HTML (eg links or form controls). Be sure
1669  * to pre-escape them if you really do want plaintext, or just wrap
1670  * the whole thing in htmlspecialchars().
1671  *
1672  * @deprecated since 1.18
1673  *
1674  * @param string $key
1675  * @param string $args,... Parameters
1676  * @return string
1677  */
1678 function wfMsgHtml( $key ) {
1679         wfDeprecated( __METHOD__, '1.21' );
1680
1681         $args = func_get_args();
1682         array_shift( $args );
1683         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1684 }
1685
1686 /**
1687  * Return an HTML version of message
1688  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1689  * so parameters may contain HTML (eg links or form controls). Be sure
1690  * to pre-escape them if you really do want plaintext, or just wrap
1691  * the whole thing in htmlspecialchars().
1692  *
1693  * @deprecated since 1.18
1694  *
1695  * @param string $key
1696  * @param string $args,... Parameters
1697  * @return string
1698  */
1699 function wfMsgWikiHtml( $key ) {
1700         wfDeprecated( __METHOD__, '1.21' );
1701
1702         $args = func_get_args();
1703         array_shift( $args );
1704         return wfMsgReplaceArgs(
1705                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1706                 /* can't be set to false */ true, /* interface */ true )->getText(),
1707                 $args );
1708 }
1709
1710 /**
1711  * Returns message in the requested format
1712  *
1713  * @deprecated since 1.18
1714  *
1715  * @param string $key Key of the message
1716  * @param array $options Processing rules.
1717  *   Can take the following options:
1718  *     parse: parses wikitext to HTML
1719  *     parseinline: parses wikitext to HTML and removes the surrounding
1720  *       p's added by parser or tidy
1721  *     escape: filters message through htmlspecialchars
1722  *     escapenoentities: same, but allows entity references like &#160; through
1723  *     replaceafter: parameters are substituted after parsing or escaping
1724  *     parsemag: transform the message using magic phrases
1725  *     content: fetch message for content language instead of interface
1726  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1727  *     language: Language object or language code to fetch message for
1728  *       (overridden by content).
1729  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1730  *
1731  * @return string
1732  */
1733 function wfMsgExt( $key, $options ) {
1734         wfDeprecated( __METHOD__, '1.21' );
1735
1736         $args = func_get_args();
1737         array_shift( $args );
1738         array_shift( $args );
1739         $options = (array)$options;
1740         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1741                 'parsemag', 'content' );
1742
1743         foreach ( $options as $arrayKey => $option ) {
1744                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1745                         // An unknown index, neither numeric nor "language"
1746                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1747                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1748                         // A numeric index with unknown value
1749                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1750                 }
1751         }
1752
1753         if ( in_array( 'content', $options, true ) ) {
1754                 $forContent = true;
1755                 $langCode = true;
1756                 $langCodeObj = null;
1757         } elseif ( array_key_exists( 'language', $options ) ) {
1758                 $forContent = false;
1759                 $langCode = wfGetLangObj( $options['language'] );
1760                 $langCodeObj = $langCode;
1761         } else {
1762                 $forContent = false;
1763                 $langCode = false;
1764                 $langCodeObj = null;
1765         }
1766
1767         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1768
1769         if ( !in_array( 'replaceafter', $options, true ) ) {
1770                 $string = wfMsgReplaceArgs( $string, $args );
1771         }
1772
1773         $messageCache = MessageCache::singleton();
1774         $parseInline = in_array( 'parseinline', $options, true );
1775         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1776                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1777                 if ( $string instanceof ParserOutput ) {
1778                         $string = $string->getText();
1779                 }
1780
1781                 if ( $parseInline ) {
1782                         $string = Parser::stripOuterParagraph( $string );
1783                 }
1784         } elseif ( in_array( 'parsemag', $options, true ) ) {
1785                 $string = $messageCache->transform( $string,
1786                                 !$forContent, $langCodeObj );
1787         }
1788
1789         if ( in_array( 'escape', $options, true ) ) {
1790                 $string = htmlspecialchars( $string );
1791         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1792                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1793         }
1794
1795         if ( in_array( 'replaceafter', $options, true ) ) {
1796                 $string = wfMsgReplaceArgs( $string, $args );
1797         }
1798
1799         return $string;
1800 }
1801
1802 /**
1803  * Since wfMsg() and co suck, they don't return false if the message key they
1804  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1805  * nonexistence of messages by checking the MessageCache::get() result directly.
1806  *
1807  * @deprecated since 1.18. Use Message::isDisabled().
1808  *
1809  * @param string $key The message key looked up
1810  * @return bool True if the message *doesn't* exist.
1811  */
1812 function wfEmptyMsg( $key ) {
1813         wfDeprecated( __METHOD__, '1.21' );
1814
1815         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1816 }
1817
1818 /**
1819  * Fetch server name for use in error reporting etc.
1820  * Use real server name if available, so we know which machine
1821  * in a server farm generated the current page.
1822  *
1823  * @return string
1824  */
1825 function wfHostname() {
1826         static $host;
1827         if ( is_null( $host ) ) {
1828
1829                 # Hostname overriding
1830                 global $wgOverrideHostname;
1831                 if ( $wgOverrideHostname !== false ) {
1832                         # Set static and skip any detection
1833                         $host = $wgOverrideHostname;
1834                         return $host;
1835                 }
1836
1837                 if ( function_exists( 'posix_uname' ) ) {
1838                         // This function not present on Windows
1839                         $uname = posix_uname();
1840                 } else {
1841                         $uname = false;
1842                 }
1843                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1844                         $host = $uname['nodename'];
1845                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1846                         # Windows computer name
1847                         $host = getenv( 'COMPUTERNAME' );
1848                 } else {
1849                         # This may be a virtual server.
1850                         $host = $_SERVER['SERVER_NAME'];
1851                 }
1852         }
1853         return $host;
1854 }
1855
1856 /**
1857  * Returns a script tag that stores the amount of time it took MediaWiki to
1858  * handle the request in milliseconds as 'wgBackendResponseTime'.
1859  *
1860  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1861  * hostname of the server handling the request.
1862  *
1863  * @return string
1864  */
1865 function wfReportTime() {
1866         global $wgRequestTime, $wgShowHostnames;
1867
1868         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1869         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1870         if ( $wgShowHostnames ) {
1871                 $reportVars['wgHostname'] = wfHostname();
1872         }
1873         return Skin::makeVariablesScript( $reportVars );
1874 }
1875
1876 /**
1877  * Safety wrapper for debug_backtrace().
1878  *
1879  * Will return an empty array if debug_backtrace is disabled, otherwise
1880  * the output from debug_backtrace() (trimmed).
1881  *
1882  * @param int $limit This parameter can be used to limit the number of stack frames returned
1883  *
1884  * @return array Array of backtrace information
1885  */
1886 function wfDebugBacktrace( $limit = 0 ) {
1887         static $disabled = null;
1888
1889         if ( is_null( $disabled ) ) {
1890                 $disabled = !function_exists( 'debug_backtrace' );
1891                 if ( $disabled ) {
1892                         wfDebug( "debug_backtrace() is disabled\n" );
1893                 }
1894         }
1895         if ( $disabled ) {
1896                 return array();
1897         }
1898
1899         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1900                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1901         } else {
1902                 return array_slice( debug_backtrace(), 1 );
1903         }
1904 }
1905
1906 /**
1907  * Get a debug backtrace as a string
1908  *
1909  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1910  *   Defaults to $wgCommandLineMode if unset.
1911  * @return string
1912  * @since 1.25 Supports $raw parameter.
1913  */
1914 function wfBacktrace( $raw = null ) {
1915         global $wgCommandLineMode;
1916
1917         if ( $raw === null ) {
1918                 $raw = $wgCommandLineMode;
1919         }
1920
1921         if ( $raw ) {
1922                 $frameFormat = "%s line %s calls %s()\n";
1923                 $traceFormat = "%s";
1924         } else {
1925                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1926                 $traceFormat = "<ul>\n%s</ul>\n";
1927         }
1928
1929         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1930                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1931                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1932                 $call = $frame['function'];
1933                 if ( !empty( $frame['class'] ) ) {
1934                         $call = $frame['class'] . $frame['type'] . $call;
1935                 }
1936                 return sprintf( $frameFormat, $file, $line, $call );
1937         }, wfDebugBacktrace() );
1938
1939         return sprintf( $traceFormat, implode( '', $frames ) );
1940 }
1941
1942 /**
1943  * Get the name of the function which called this function
1944  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1945  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1946  * wfGetCaller( 3 ) is the parent of that.
1947  *
1948  * @param int $level
1949  * @return string
1950  */
1951 function wfGetCaller( $level = 2 ) {
1952         $backtrace = wfDebugBacktrace( $level + 1 );
1953         if ( isset( $backtrace[$level] ) ) {
1954                 return wfFormatStackFrame( $backtrace[$level] );
1955         } else {
1956                 return 'unknown';
1957         }
1958 }
1959
1960 /**
1961  * Return a string consisting of callers in the stack. Useful sometimes
1962  * for profiling specific points.
1963  *
1964  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1965  * @return string
1966  */
1967 function wfGetAllCallers( $limit = 3 ) {
1968         $trace = array_reverse( wfDebugBacktrace() );
1969         if ( !$limit || $limit > count( $trace ) - 1 ) {
1970                 $limit = count( $trace ) - 1;
1971         }
1972         $trace = array_slice( $trace, -$limit - 1, $limit );
1973         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1974 }
1975
1976 /**
1977  * Return a string representation of frame
1978  *
1979  * @param array $frame
1980  * @return string
1981  */
1982 function wfFormatStackFrame( $frame ) {
1983         if ( !isset( $frame['function'] ) ) {
1984                 return 'NO_FUNCTION_GIVEN';
1985         }
1986         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1987                 $frame['class'] . $frame['type'] . $frame['function'] :
1988                 $frame['function'];
1989 }
1990
1991 /* Some generic result counters, pulled out of SearchEngine */
1992
1993 /**
1994  * @todo document
1995  *
1996  * @param int $offset
1997  * @param int $limit
1998  * @return string
1999  */
2000 function wfShowingResults( $offset, $limit ) {
2001         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
2002 }
2003
2004 /**
2005  * @todo document
2006  * @todo FIXME: We may want to blacklist some broken browsers
2007  *
2008  * @param bool $force
2009  * @return bool Whereas client accept gzip compression
2010  */
2011 function wfClientAcceptsGzip( $force = false ) {
2012         static $result = null;
2013         if ( $result === null || $force ) {
2014                 $result = false;
2015                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2016                         # @todo FIXME: We may want to blacklist some broken browsers
2017                         $m = array();
2018                         if ( preg_match(
2019                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2020                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
2021                                         $m
2022                                 )
2023                         ) {
2024                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2025                                         $result = false;
2026                                         return $result;
2027                                 }
2028                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2029                                 $result = true;
2030                         }
2031                 }
2032         }
2033         return $result;
2034 }
2035
2036 /**
2037  * Obtain the offset and limit values from the request string;
2038  * used in special pages
2039  *
2040  * @param int $deflimit Default limit if none supplied
2041  * @param string $optionname Name of a user preference to check against
2042  * @return array
2043  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2044  */
2045 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2046         global $wgRequest;
2047         wfDeprecated( __METHOD__, '1.24' );
2048         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2049 }
2050
2051 /**
2052  * Escapes the given text so that it may be output using addWikiText()
2053  * without any linking, formatting, etc. making its way through. This
2054  * is achieved by substituting certain characters with HTML entities.
2055  * As required by the callers, "<nowiki>" is not used.
2056  *
2057  * @param string $text Text to be escaped
2058  * @return string
2059  */
2060 function wfEscapeWikiText( $text ) {
2061         static $repl = null, $repl2 = null;
2062         if ( $repl === null ) {
2063                 $repl = array(
2064                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2065                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2066                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2067                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2068                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2069                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2070                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2071                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2072                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2073                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2074                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2075                         '__' => '_&#95;', '://' => '&#58;//',
2076                 );
2077
2078                 // We have to catch everything "\s" matches in PCRE
2079                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2080                         $repl["$magic "] = "$magic&#32;";
2081                         $repl["$magic\t"] = "$magic&#9;";
2082                         $repl["$magic\r"] = "$magic&#13;";
2083                         $repl["$magic\n"] = "$magic&#10;";
2084                         $repl["$magic\f"] = "$magic&#12;";
2085                 }
2086
2087                 // And handle protocols that don't use "://"
2088                 global $wgUrlProtocols;
2089                 $repl2 = array();
2090                 foreach ( $wgUrlProtocols as $prot ) {
2091                         if ( substr( $prot, -1 ) === ':' ) {
2092                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2093                         }
2094                 }
2095                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2096         }
2097         $text = substr( strtr( "\n$text", $repl ), 1 );
2098         $text = preg_replace( $repl2, '$1&#58;', $text );
2099         return $text;
2100 }
2101
2102 /**
2103  * Sets dest to source and returns the original value of dest
2104  * If source is NULL, it just returns the value, it doesn't set the variable
2105  * If force is true, it will set the value even if source is NULL
2106  *
2107  * @param mixed $dest
2108  * @param mixed $source
2109  * @param bool $force
2110  * @return mixed
2111  */
2112 function wfSetVar( &$dest, $source, $force = false ) {
2113         $temp = $dest;
2114         if ( !is_null( $source ) || $force ) {
2115                 $dest = $source;
2116         }
2117         return $temp;
2118 }
2119
2120 /**
2121  * As for wfSetVar except setting a bit
2122  *
2123  * @param int $dest
2124  * @param int $bit
2125  * @param bool $state
2126  *
2127  * @return bool
2128  */
2129 function wfSetBit( &$dest, $bit, $state = true ) {
2130         $temp = (bool)( $dest & $bit );
2131         if ( !is_null( $state ) ) {
2132                 if ( $state ) {
2133                         $dest |= $bit;
2134                 } else {
2135                         $dest &= ~$bit;
2136                 }
2137         }
2138         return $temp;
2139 }
2140
2141 /**
2142  * A wrapper around the PHP function var_export().
2143  * Either print it or add it to the regular output ($wgOut).
2144  *
2145  * @param mixed $var A PHP variable to dump.
2146  */
2147 function wfVarDump( $var ) {
2148         global $wgOut;
2149         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2150         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2151                 print $s;
2152         } else {
2153                 $wgOut->addHTML( $s );
2154         }
2155 }
2156
2157 /**
2158  * Provide a simple HTTP error.
2159  *
2160  * @param int|string $code
2161  * @param string $label
2162  * @param string $desc
2163  */
2164 function wfHttpError( $code, $label, $desc ) {
2165         global $wgOut;
2166         HttpStatus::header( $code );
2167         if ( $wgOut ) {
2168                 $wgOut->disable();
2169                 $wgOut->sendCacheControl();
2170         }
2171
2172         header( 'Content-type: text/html; charset=utf-8' );
2173         print '<!DOCTYPE html>' .
2174                 '<html><head><title>' .
2175                 htmlspecialchars( $label ) .
2176                 '</title></head><body><h1>' .
2177                 htmlspecialchars( $label ) .
2178                 '</h1><p>' .
2179                 nl2br( htmlspecialchars( $desc ) ) .
2180                 "</p></body></html>\n";
2181 }
2182
2183 /**
2184  * Clear away any user-level output buffers, discarding contents.
2185  *
2186  * Suitable for 'starting afresh', for instance when streaming
2187  * relatively large amounts of data without buffering, or wanting to
2188  * output image files without ob_gzhandler's compression.
2189  *
2190  * The optional $resetGzipEncoding parameter controls suppression of
2191  * the Content-Encoding header sent by ob_gzhandler; by default it
2192  * is left. See comments for wfClearOutputBuffers() for why it would
2193  * be used.
2194  *
2195  * Note that some PHP configuration options may add output buffer
2196  * layers which cannot be removed; these are left in place.
2197  *
2198  * @param bool $resetGzipEncoding
2199  */
2200 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2201         if ( $resetGzipEncoding ) {
2202                 // Suppress Content-Encoding and Content-Length
2203                 // headers from 1.10+s wfOutputHandler
2204                 global $wgDisableOutputCompression;
2205                 $wgDisableOutputCompression = true;
2206         }
2207         while ( $status = ob_get_status() ) {
2208                 if ( isset( $status['flags'] ) ) {
2209                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
2210                         $deleteable = ( $status['flags'] & $flags ) === $flags;
2211                 } elseif ( isset( $status['del'] ) ) {
2212                         $deleteable = $status['del'];
2213                 } else {
2214                         // Guess that any PHP-internal setting can't be removed.
2215                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
2216                 }
2217                 if ( !$deleteable ) {
2218                         // Give up, and hope the result doesn't break
2219                         // output behavior.
2220                         break;
2221                 }
2222                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
2223                         // Unit testing barrier to prevent this function from breaking PHPUnit.
2224                         break;
2225                 }
2226                 if ( !ob_end_clean() ) {
2227                         // Could not remove output buffer handler; abort now
2228                         // to avoid getting in some kind of infinite loop.
2229                         break;
2230                 }
2231                 if ( $resetGzipEncoding ) {
2232                         if ( $status['name'] == 'ob_gzhandler' ) {
2233                                 // Reset the 'Content-Encoding' field set by this handler
2234                                 // so we can start fresh.
2235                                 header_remove( 'Content-Encoding' );
2236                                 break;
2237                         }
2238                 }
2239         }
2240 }
2241
2242 /**
2243  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2244  *
2245  * Clear away output buffers, but keep the Content-Encoding header
2246  * produced by ob_gzhandler, if any.
2247  *
2248  * This should be used for HTTP 304 responses, where you need to
2249  * preserve the Content-Encoding header of the real result, but
2250  * also need to suppress the output of ob_gzhandler to keep to spec
2251  * and avoid breaking Firefox in rare cases where the headers and
2252  * body are broken over two packets.
2253  */
2254 function wfClearOutputBuffers() {
2255         wfResetOutputBuffers( false );
2256 }
2257
2258 /**
2259  * Converts an Accept-* header into an array mapping string values to quality
2260  * factors
2261  *
2262  * @param string $accept
2263  * @param string $def Default
2264  * @return float[] Associative array of string => float pairs
2265  */
2266 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2267         # No arg means accept anything (per HTTP spec)
2268         if ( !$accept ) {
2269                 return array( $def => 1.0 );
2270         }
2271
2272         $prefs = array();
2273
2274         $parts = explode( ',', $accept );
2275
2276         foreach ( $parts as $part ) {
2277                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2278                 $values = explode( ';', trim( $part ) );
2279                 $match = array();
2280                 if ( count( $values ) == 1 ) {
2281                         $prefs[$values[0]] = 1.0;
2282                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2283                         $prefs[$values[0]] = floatval( $match[1] );
2284                 }
2285         }
2286
2287         return $prefs;
2288 }
2289
2290 /**
2291  * Checks if a given MIME type matches any of the keys in the given
2292  * array. Basic wildcards are accepted in the array keys.
2293  *
2294  * Returns the matching MIME type (or wildcard) if a match, otherwise
2295  * NULL if no match.
2296  *
2297  * @param string $type
2298  * @param array $avail
2299  * @return string
2300  * @private
2301  */
2302 function mimeTypeMatch( $type, $avail ) {
2303         if ( array_key_exists( $type, $avail ) ) {
2304                 return $type;
2305         } else {
2306                 $parts = explode( '/', $type );
2307                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2308                         return $parts[0] . '/*';
2309                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2310                         return '*/*';
2311                 } else {
2312                         return null;
2313                 }
2314         }
2315 }
2316
2317 /**
2318  * Returns the 'best' match between a client's requested internet media types
2319  * and the server's list of available types. Each list should be an associative
2320  * array of type to preference (preference is a float between 0.0 and 1.0).
2321  * Wildcards in the types are acceptable.
2322  *
2323  * @param array $cprefs Client's acceptable type list
2324  * @param array $sprefs Server's offered types
2325  * @return string
2326  *
2327  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2328  * XXX: generalize to negotiate other stuff
2329  */
2330 function wfNegotiateType( $cprefs, $sprefs ) {
2331         $combine = array();
2332
2333         foreach ( array_keys( $sprefs ) as $type ) {
2334                 $parts = explode( '/', $type );
2335                 if ( $parts[1] != '*' ) {
2336                         $ckey = mimeTypeMatch( $type, $cprefs );
2337                         if ( $ckey ) {
2338                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2339                         }
2340                 }
2341         }
2342
2343         foreach ( array_keys( $cprefs ) as $type ) {
2344                 $parts = explode( '/', $type );
2345                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2346                         $skey = mimeTypeMatch( $type, $sprefs );
2347                         if ( $skey ) {
2348                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2349                         }
2350                 }
2351         }
2352
2353         $bestq = 0;
2354         $besttype = null;
2355
2356         foreach ( array_keys( $combine ) as $type ) {
2357                 if ( $combine[$type] > $bestq ) {
2358                         $besttype = $type;
2359                         $bestq = $combine[$type];
2360                 }
2361         }
2362
2363         return $besttype;
2364 }
2365
2366 /**
2367  * Reference-counted warning suppression
2368  *
2369  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
2370  * @param bool $end
2371  */
2372 function wfSuppressWarnings( $end = false ) {
2373         MediaWiki\suppressWarnings( $end );
2374 }
2375
2376 /**
2377  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
2378  * Restore error level to previous value
2379  */
2380 function wfRestoreWarnings() {
2381         MediaWiki\suppressWarnings( true );
2382 }
2383
2384 # Autodetect, convert and provide timestamps of various types
2385
2386 /**
2387  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2388  */
2389 define( 'TS_UNIX', 0 );
2390
2391 /**
2392  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2393  */
2394 define( 'TS_MW', 1 );
2395
2396 /**
2397  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2398  */
2399 define( 'TS_DB', 2 );
2400
2401 /**
2402  * RFC 2822 format, for E-mail and HTTP headers
2403  */
2404 define( 'TS_RFC2822', 3 );
2405
2406 /**
2407  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2408  *
2409  * This is used by Special:Export
2410  */
2411 define( 'TS_ISO_8601', 4 );
2412
2413 /**
2414  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2415  *
2416  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2417  *       DateTime tag and page 36 for the DateTimeOriginal and
2418  *       DateTimeDigitized tags.
2419  */
2420 define( 'TS_EXIF', 5 );
2421
2422 /**
2423  * Oracle format time.
2424  */
2425 define( 'TS_ORACLE', 6 );
2426
2427 /**
2428  * Postgres format time.
2429  */
2430 define( 'TS_POSTGRES', 7 );
2431
2432 /**
2433  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2434  */
2435 define( 'TS_ISO_8601_BASIC', 9 );
2436
2437 /**
2438  * Get a timestamp string in one of various formats
2439  *
2440  * @param mixed $outputtype A timestamp in one of the supported formats, the
2441  *   function will autodetect which format is supplied and act accordingly.
2442  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2443  * @return string|bool String / false The same date in the format specified in $outputtype or false
2444  */
2445 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2446         try {
2447                 $timestamp = new MWTimestamp( $ts );
2448                 return $timestamp->getTimestamp( $outputtype );
2449         } catch ( TimestampException $e ) {
2450                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2451                 return false;
2452         }
2453 }
2454
2455 /**
2456  * Return a formatted timestamp, or null if input is null.
2457  * For dealing with nullable timestamp columns in the database.
2458  *
2459  * @param int $outputtype
2460  * @param string $ts
2461  * @return string
2462  */
2463 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2464         if ( is_null( $ts ) ) {
2465                 return null;
2466         } else {
2467                 return wfTimestamp( $outputtype, $ts );
2468         }
2469 }
2470
2471 /**
2472  * Convenience function; returns MediaWiki timestamp for the present time.
2473  *
2474  * @return string
2475  */
2476 function wfTimestampNow() {
2477         # return NOW
2478         return wfTimestamp( TS_MW, time() );
2479 }
2480
2481 /**
2482  * Check if the operating system is Windows
2483  *
2484  * @return bool True if it's Windows, false otherwise.
2485  */
2486 function wfIsWindows() {
2487         static $isWindows = null;
2488         if ( $isWindows === null ) {
2489                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2490         }
2491         return $isWindows;
2492 }
2493
2494 /**
2495  * Check if we are running under HHVM
2496  *
2497  * @return bool
2498  */
2499 function wfIsHHVM() {
2500         return defined( 'HHVM_VERSION' );
2501 }
2502
2503 /**
2504  * Tries to get the system directory for temporary files. First
2505  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2506  * environment variables are then checked in sequence, and if none are
2507  * set try sys_get_temp_dir().
2508  *
2509  * NOTE: When possible, use instead the tmpfile() function to create
2510  * temporary files to avoid race conditions on file creation, etc.
2511  *
2512  * @return string
2513  */
2514 function wfTempDir() {
2515         global $wgTmpDirectory;
2516
2517         if ( $wgTmpDirectory !== false ) {
2518                 return $wgTmpDirectory;
2519         }
2520
2521         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2522
2523         foreach ( $tmpDir as $tmp ) {
2524                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2525                         return $tmp;
2526                 }
2527         }
2528         return sys_get_temp_dir();
2529 }
2530
2531 /**
2532  * Make directory, and make all parent directories if they don't exist
2533  *
2534  * @param string $dir Full path to directory to create
2535  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2536  * @param string $caller Optional caller param for debugging.
2537  * @throws MWException
2538  * @return bool
2539  */
2540 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2541         global $wgDirectoryMode;
2542
2543         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2544                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2545         }
2546
2547         if ( !is_null( $caller ) ) {
2548                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2549         }
2550
2551         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2552                 return true;
2553         }
2554
2555         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2556
2557         if ( is_null( $mode ) ) {
2558                 $mode = $wgDirectoryMode;
2559         }
2560
2561         // Turn off the normal warning, we're doing our own below
2562         MediaWiki\suppressWarnings();
2563         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2564         MediaWiki\restoreWarnings();
2565
2566         if ( !$ok ) {
2567                 // directory may have been created on another request since we last checked
2568                 if ( is_dir( $dir ) ) {
2569                         return true;
2570                 }
2571
2572                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2573                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2574         }
2575         return $ok;
2576 }
2577
2578 /**
2579  * Remove a directory and all its content.
2580  * Does not hide error.
2581  * @param string $dir
2582  */
2583 function wfRecursiveRemoveDir( $dir ) {
2584         wfDebug( __FUNCTION__ . "( $dir )\n" );
2585         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2586         if ( is_dir( $dir ) ) {
2587                 $objects = scandir( $dir );
2588                 foreach ( $objects as $object ) {
2589                         if ( $object != "." && $object != ".." ) {
2590                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2591                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2592                                 } else {
2593                                         unlink( $dir . '/' . $object );
2594                                 }
2595                         }
2596                 }
2597                 reset( $objects );
2598                 rmdir( $dir );
2599         }
2600 }
2601
2602 /**
2603  * @param int $nr The number to format
2604  * @param int $acc The number of digits after the decimal point, default 2
2605  * @param bool $round Whether or not to round the value, default true
2606  * @return string
2607  */
2608 function wfPercent( $nr, $acc = 2, $round = true ) {
2609         $ret = sprintf( "%.${acc}f", $nr );
2610         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2611 }
2612
2613 /**
2614  * Safety wrapper around ini_get() for boolean settings.
2615  * The values returned from ini_get() are pre-normalized for settings
2616  * set via php.ini or php_flag/php_admin_flag... but *not*
2617  * for those set via php_value/php_admin_value.
2618  *
2619  * It's fairly common for people to use php_value instead of php_flag,
2620  * which can leave you with an 'off' setting giving a false positive
2621  * for code that just takes the ini_get() return value as a boolean.
2622  *
2623  * To make things extra interesting, setting via php_value accepts
2624  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2625  * Unrecognized values go false... again opposite PHP's own coercion
2626  * from string to bool.
2627  *
2628  * Luckily, 'properly' set settings will always come back as '0' or '1',
2629  * so we only have to worry about them and the 'improper' settings.
2630  *
2631  * I frickin' hate PHP... :P
2632  *
2633  * @param string $setting
2634  * @return bool
2635  */
2636 function wfIniGetBool( $setting ) {
2637         $val = strtolower( ini_get( $setting ) );
2638         // 'on' and 'true' can't have whitespace around them, but '1' can.
2639         return $val == 'on'
2640                 || $val == 'true'
2641                 || $val == 'yes'
2642                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2643 }
2644
2645 /**
2646  * Windows-compatible version of escapeshellarg()
2647  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2648  * function puts single quotes in regardless of OS.
2649  *
2650  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2651  * earlier distro releases of PHP)
2652  *
2653  * @param string ... strings to escape and glue together, or a single array of strings parameter
2654  * @return string
2655  */
2656 function wfEscapeShellArg( /*...*/ ) {
2657         wfInitShellLocale();
2658
2659         $args = func_get_args();
2660         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2661                 // If only one argument has been passed, and that argument is an array,
2662                 // treat it as a list of arguments
2663                 $args = reset( $args );
2664         }
2665
2666         $first = true;
2667         $retVal = '';
2668         foreach ( $args as $arg ) {
2669                 if ( !$first ) {
2670                         $retVal .= ' ';
2671                 } else {
2672                         $first = false;
2673                 }
2674
2675                 if ( wfIsWindows() ) {
2676                         // Escaping for an MSVC-style command line parser and CMD.EXE
2677                         // @codingStandardsIgnoreStart For long URLs
2678                         // Refs:
2679                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2680                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2681                         //  * Bug #13518
2682                         //  * CR r63214
2683                         // Double the backslashes before any double quotes. Escape the double quotes.
2684                         // @codingStandardsIgnoreEnd
2685                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2686                         $arg = '';
2687                         $iteration = 0;
2688                         foreach ( $tokens as $token ) {
2689                                 if ( $iteration % 2 == 1 ) {
2690                                         // Delimiter, a double quote preceded by zero or more slashes
2691                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2692                                 } elseif ( $iteration % 4 == 2 ) {
2693                                         // ^ in $token will be outside quotes, need to be escaped
2694                                         $arg .= str_replace( '^', '^^', $token );
2695                                 } else { // $iteration % 4 == 0
2696                                         // ^ in $token will appear inside double quotes, so leave as is
2697                                         $arg .= $token;
2698                                 }
2699                                 $iteration++;
2700                         }
2701                         // Double the backslashes before the end of the string, because
2702                         // we will soon add a quote
2703                         $m = array();
2704                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2705                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2706                         }
2707
2708                         // Add surrounding quotes
2709                         $retVal .= '"' . $arg . '"';
2710                 } else {
2711                         $retVal .= escapeshellarg( $arg );
2712                 }
2713         }
2714         return $retVal;
2715 }
2716
2717 /**
2718  * Check if wfShellExec() is effectively disabled via php.ini config
2719  *
2720  * @return bool|string False or one of (safemode,disabled)
2721  * @since 1.22
2722  */
2723 function wfShellExecDisabled() {
2724         static $disabled = null;
2725         if ( is_null( $disabled ) ) {
2726                 if ( wfIniGetBool( 'safe_mode' ) ) {
2727                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2728                         $disabled = 'safemode';
2729                 } elseif ( !function_exists( 'proc_open' ) ) {
2730                         wfDebug( "proc_open() is disabled\n" );
2731                         $disabled = 'disabled';
2732                 } else {
2733                         $disabled = false;
2734                 }
2735         }
2736         return $disabled;
2737 }
2738
2739 /**
2740  * Execute a shell command, with time and memory limits mirrored from the PHP
2741  * configuration if supported.
2742  *
2743  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2744  *   or an array of unescaped arguments, in which case each value will be escaped
2745  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2746  * @param null|mixed &$retval Optional, will receive the program's exit code.
2747  *   (non-zero is usually failure). If there is an error from
2748  *   read, select, or proc_open(), this will be set to -1.
2749  * @param array $environ Optional environment variables which should be
2750  *   added to the executed command environment.
2751  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2752  *   this overwrites the global wgMaxShell* limits.
2753  * @param array $options Array of options:
2754  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2755  *     including errors from limit.sh
2756  *   - profileMethod: By default this function will profile based on the calling
2757  *     method. Set this to a string for an alternative method to profile from
2758  *
2759  * @return string Collected stdout as a string
2760  */
2761 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2762         $limits = array(), $options = array()
2763 ) {
2764         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2765                 $wgMaxShellWallClockTime, $wgShellCgroup;
2766
2767         $disabled = wfShellExecDisabled();
2768         if ( $disabled ) {
2769                 $retval = 1;
2770                 return $disabled == 'safemode' ?
2771                         'Unable to run external programs in safe mode.' :
2772                         'Unable to run external programs, proc_open() is disabled.';
2773         }
2774
2775         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2776         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2777
2778         wfInitShellLocale();
2779
2780         $envcmd = '';
2781         foreach ( $environ as $k => $v ) {
2782                 if ( wfIsWindows() ) {
2783                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2784                          * appear in the environment variable, so we must use carat escaping as documented in
2785                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2786                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2787                          * are listed there but doesn't appear to need it.
2788                          */
2789                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2790                 } else {
2791                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2792                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2793                          */
2794                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2795                 }
2796         }
2797         if ( is_array( $cmd ) ) {
2798                 $cmd = wfEscapeShellArg( $cmd );
2799         }
2800
2801         $cmd = $envcmd . $cmd;
2802
2803         $useLogPipe = false;
2804         if ( is_executable( '/bin/bash' ) ) {
2805                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2806                 if ( isset( $limits['walltime'] ) ) {
2807                         $wallTime = intval( $limits['walltime'] );
2808                 } elseif ( isset( $limits['time'] ) ) {
2809                         $wallTime = $time;
2810                 } else {
2811                         $wallTime = intval( $wgMaxShellWallClockTime );
2812                 }
2813                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2814                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2815
2816                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2817                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2818                                 escapeshellarg( $cmd ) . ' ' .
2819                                 escapeshellarg(
2820                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2821                                         "MW_CPU_LIMIT=$time; " .
2822                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2823                                         "MW_MEM_LIMIT=$mem; " .
2824                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2825                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2826                                         "MW_USE_LOG_PIPE=yes"
2827                                 );
2828                         $useLogPipe = true;
2829                 } elseif ( $includeStderr ) {
2830                         $cmd .= ' 2>&1';
2831                 }
2832         } elseif ( $includeStderr ) {
2833                 $cmd .= ' 2>&1';
2834         }
2835         wfDebug( "wfShellExec: $cmd\n" );
2836
2837         $desc = array(
2838                 0 => array( 'file', 'php://stdin', 'r' ),
2839                 1 => array( 'pipe', 'w' ),
2840                 2 => array( 'file', 'php://stderr', 'w' ) );
2841         if ( $useLogPipe ) {
2842                 $desc[3] = array( 'pipe', 'w' );
2843         }
2844         $pipes = null;
2845         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2846         $proc = proc_open( $cmd, $desc, $pipes );
2847         if ( !$proc ) {
2848                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2849                 $retval = -1;
2850                 return '';
2851         }
2852         $outBuffer = $logBuffer = '';
2853         $emptyArray = array();
2854         $status = false;
2855         $logMsg = false;
2856
2857         /* According to the documentation, it is possible for stream_select()
2858          * to fail due to EINTR. I haven't managed to induce this in testing
2859          * despite sending various signals. If it did happen, the error
2860          * message would take the form:
2861          *
2862          * stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2863          *
2864          * where [4] is the value of the macro EINTR and "Interrupted system
2865          * call" is string which according to the Linux manual is "possibly"
2866          * localised according to LC_MESSAGES.
2867          */
2868         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2869         $eintrMessage = "stream_select(): unable to select [$eintr]";
2870
2871         // Build a table mapping resource IDs to pipe FDs to work around a
2872         // PHP 5.3 issue in which stream_select() does not preserve array keys
2873         // <https://bugs.php.net/bug.php?id=53427>.
2874         $fds = array();
2875         foreach ( $pipes as $fd => $pipe ) {
2876                 $fds[(int)$pipe] = $fd;
2877         }
2878
2879         $running = true;
2880         $timeout = null;
2881         $numReadyPipes = 0;
2882
2883         while ( $running === true || $numReadyPipes !== 0 ) {
2884                 if ( $running ) {
2885                         $status = proc_get_status( $proc );
2886                         // If the process has terminated, switch to nonblocking selects
2887                         // for getting any data still waiting to be read.
2888                         if ( !$status['running'] ) {
2889                                 $running = false;
2890                                 $timeout = 0;
2891                         }
2892                 }
2893
2894                 $readyPipes = $pipes;
2895
2896                 // Clear last error
2897                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2898                 @trigger_error( '' );
2899                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2900                 if ( $numReadyPipes === false ) {
2901                         // @codingStandardsIgnoreEnd
2902                         $error = error_get_last();
2903                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2904                                 continue;
2905                         } else {
2906                                 trigger_error( $error['message'], E_USER_WARNING );
2907                                 $logMsg = $error['message'];
2908                                 break;
2909                         }
2910                 }
2911                 foreach ( $readyPipes as $pipe ) {
2912                         $block = fread( $pipe, 65536 );
2913                         $fd = $fds[(int)$pipe];
2914                         if ( $block === '' ) {
2915                                 // End of file
2916                                 fclose( $pipes[$fd] );
2917                                 unset( $pipes[$fd] );
2918                                 if ( !$pipes ) {
2919                                         break 2;
2920                                 }
2921                         } elseif ( $block === false ) {
2922                                 // Read error
2923                                 $logMsg = "Error reading from pipe";
2924                                 break 2;
2925                         } elseif ( $fd == 1 ) {
2926                                 // From stdout
2927                                 $outBuffer .= $block;
2928                         } elseif ( $fd == 3 ) {
2929                                 // From log FD
2930                                 $logBuffer .= $block;
2931                                 if ( strpos( $block, "\n" ) !== false ) {
2932                                         $lines = explode( "\n", $logBuffer );
2933                                         $logBuffer = array_pop( $lines );
2934                                         foreach ( $lines as $line ) {
2935                                                 wfDebugLog( 'exec', $line );
2936                                         }
2937                                 }
2938                         }
2939                 }
2940         }
2941
2942         foreach ( $pipes as $pipe ) {
2943                 fclose( $pipe );
2944         }
2945
2946         // Use the status previously collected if possible, since proc_get_status()
2947         // just calls waitpid() which will not return anything useful the second time.
2948         if ( $running ) {
2949                 $status = proc_get_status( $proc );
2950         }
2951
2952         if ( $logMsg !== false ) {
2953                 // Read/select error
2954                 $retval = -1;
2955                 proc_close( $proc );
2956         } elseif ( $status['signaled'] ) {
2957                 $logMsg = "Exited with signal {$status['termsig']}";
2958                 $retval = 128 + $status['termsig'];
2959                 proc_close( $proc );
2960         } else {
2961                 if ( $status['running'] ) {
2962                         $retval = proc_close( $proc );
2963                 } else {
2964                         $retval = $status['exitcode'];
2965                         proc_close( $proc );
2966                 }
2967                 if ( $retval == 127 ) {
2968                         $logMsg = "Possibly missing executable file";
2969                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2970                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2971                 }
2972         }
2973
2974         if ( $logMsg !== false ) {
2975                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2976         }
2977
2978         return $outBuffer;
2979 }
2980
2981 /**
2982  * Execute a shell command, returning both stdout and stderr. Convenience
2983  * function, as all the arguments to wfShellExec can become unwieldy.
2984  *
2985  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2986  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2987  *   or an array of unescaped arguments, in which case each value will be escaped
2988  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2989  * @param null|mixed &$retval Optional, will receive the program's exit code.
2990  *   (non-zero is usually failure)
2991  * @param array $environ Optional environment variables which should be
2992  *   added to the executed command environment.
2993  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2994  *   this overwrites the global wgMaxShell* limits.
2995  * @return string Collected stdout and stderr as a string
2996  */
2997 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2998         return wfShellExec( $cmd, $retval, $environ, $limits,
2999                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
3000 }
3001
3002 /**
3003  * Workaround for http://bugs.php.net/bug.php?id=45132
3004  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
3005  */
3006 function wfInitShellLocale() {
3007         static $done = false;
3008         if ( $done ) {
3009                 return;
3010         }
3011         $done = true;
3012         global $wgShellLocale;
3013         if ( !wfIniGetBool( 'safe_mode' ) ) {
3014                 putenv( "LC_CTYPE=$wgShellLocale" );
3015                 setlocale( LC_CTYPE, $wgShellLocale );
3016         }
3017 }
3018
3019 /**
3020  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3021  * Note that $parameters should be a flat array and an option with an argument
3022  * should consist of two consecutive items in the array (do not use "--option value").
3023  *
3024  * @param string $script MediaWiki cli script path
3025  * @param array $parameters Arguments and options to the script
3026  * @param array $options Associative array of options:
3027  *              'php': The path to the php executable
3028  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3029  * @return string
3030  */
3031 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3032         global $wgPhpCli;
3033         // Give site config file a chance to run the script in a wrapper.
3034         // The caller may likely want to call wfBasename() on $script.
3035         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3036         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3037         if ( isset( $options['wrapper'] ) ) {
3038                 $cmd[] = $options['wrapper'];
3039         }
3040         $cmd[] = $script;
3041         // Escape each parameter for shell
3042         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3043 }
3044
3045 /**
3046  * wfMerge attempts to merge differences between three texts.
3047  * Returns true for a clean merge and false for failure or a conflict.
3048  *
3049  * @param string $old
3050  * @param string $mine
3051  * @param string $yours
3052  * @param string $result
3053  * @return bool
3054  */
3055 function wfMerge( $old, $mine, $yours, &$result ) {
3056         global $wgDiff3;
3057
3058         # This check may also protect against code injection in
3059         # case of broken installations.
3060         MediaWiki\suppressWarnings();
3061         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3062         MediaWiki\restoreWarnings();
3063
3064         if ( !$haveDiff3 ) {
3065                 wfDebug( "diff3 not found\n" );
3066                 return false;
3067         }
3068
3069         # Make temporary files
3070         $td = wfTempDir();
3071         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3072         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3073         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3074
3075         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3076         #       a newline character. To avoid this, we normalize the trailing whitespace before
3077         #       creating the diff.
3078
3079         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3080         fclose( $oldtextFile );
3081         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3082         fclose( $mytextFile );
3083         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3084         fclose( $yourtextFile );
3085
3086         # Check for a conflict
3087         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
3088                 $oldtextName, $yourtextName );
3089         $handle = popen( $cmd, 'r' );
3090
3091         if ( fgets( $handle, 1024 ) ) {
3092                 $conflict = true;
3093         } else {
3094                 $conflict = false;
3095         }
3096         pclose( $handle );
3097
3098         # Merge differences
3099         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
3100                 $oldtextName, $yourtextName );
3101         $handle = popen( $cmd, 'r' );
3102         $result = '';
3103         do {
3104                 $data = fread( $handle, 8192 );
3105                 if ( strlen( $data ) == 0 ) {
3106                         break;
3107                 }
3108                 $result .= $data;
3109         } while ( true );
3110         pclose( $handle );
3111         unlink( $mytextName );
3112         unlink( $oldtextName );
3113         unlink( $yourtextName );
3114
3115         if ( $result === '' && $old !== '' && !$conflict ) {
3116                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3117                 $conflict = true;
3118         }
3119         return !$conflict;
3120 }
3121
3122 /**
3123  * Returns unified plain-text diff of two texts.
3124  * "Useful" for machine processing of diffs.
3125  *
3126  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3127  *
3128  * @param string $before The text before the changes.
3129  * @param string $after The text after the changes.
3130  * @param string $params Command-line options for the diff command.
3131  * @return string Unified diff of $before and $after
3132  */
3133 function wfDiff( $before, $after, $params = '-u' ) {
3134         if ( $before == $after ) {
3135                 return '';
3136         }
3137
3138         global $wgDiff;
3139         MediaWiki\suppressWarnings();
3140         $haveDiff = $wgDiff && file_exists( $wgDiff );
3141         MediaWiki\restoreWarnings();
3142
3143         # This check may also protect against code injection in
3144         # case of broken installations.
3145         if ( !$haveDiff ) {
3146                 wfDebug( "diff executable not found\n" );
3147                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3148                 $format = new UnifiedDiffFormatter();
3149                 return $format->format( $diffs );
3150         }
3151
3152         # Make temporary files
3153         $td = wfTempDir();
3154         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3155         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3156
3157         fwrite( $oldtextFile, $before );
3158         fclose( $oldtextFile );
3159         fwrite( $newtextFile, $after );
3160         fclose( $newtextFile );
3161
3162         // Get the diff of the two files
3163         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3164
3165         $h = popen( $cmd, 'r' );
3166         if ( !$h ) {
3167                 unlink( $oldtextName );
3168                 unlink( $newtextName );
3169                 throw new Exception( __METHOD__ . '(): popen() failed' );
3170         }
3171
3172         $diff = '';
3173
3174         do {
3175                 $data = fread( $h, 8192 );
3176                 if ( strlen( $data ) == 0 ) {
3177                         break;
3178                 }
3179                 $diff .= $data;
3180         } while ( true );
3181
3182         // Clean up
3183         pclose( $h );
3184         unlink( $oldtextName );
3185         unlink( $newtextName );
3186
3187         // Kill the --- and +++ lines. They're not useful.
3188         $diff_lines = explode( "\n", $diff );
3189         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3190                 unset( $diff_lines[0] );
3191         }
3192         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3193                 unset( $diff_lines[1] );
3194         }
3195
3196         $diff = implode( "\n", $diff_lines );
3197
3198         return $diff;
3199 }
3200
3201 /**
3202  * This function works like "use VERSION" in Perl, the program will die with a
3203  * backtrace if the current version of PHP is less than the version provided
3204  *
3205  * This is useful for extensions which due to their nature are not kept in sync
3206  * with releases, and might depend on other versions of PHP than the main code
3207  *
3208  * Note: PHP might die due to parsing errors in some cases before it ever
3209  *       manages to call this function, such is life
3210  *
3211  * @see perldoc -f use
3212  *
3213  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3214  * @throws MWException
3215  */
3216 function wfUsePHP( $req_ver ) {
3217         $php_ver = PHP_VERSION;
3218
3219         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3220                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3221         }
3222 }
3223
3224 /**
3225  * This function works like "use VERSION" in Perl except it checks the version
3226  * of MediaWiki, the program will die with a backtrace if the current version
3227  * of MediaWiki is less than the version provided.
3228  *
3229  * This is useful for extensions which due to their nature are not kept in sync
3230  * with releases
3231  *
3232  * Note: Due to the behavior of PHP's version_compare() which is used in this
3233  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3234  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3235  * targeted version number. For example if you wanted to allow any variation
3236  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3237  * not result in the same comparison due to the internal logic of
3238  * version_compare().
3239  *
3240  * @see perldoc -f use
3241  *
3242  * @deprecated since 1.26, use the "requires' property of extension.json
3243  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3244  * @throws MWException
3245  */
3246 function wfUseMW( $req_ver ) {
3247         global $wgVersion;
3248
3249         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3250                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3251         }
3252 }
3253
3254 /**
3255  * Return the final portion of a pathname.
3256  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3257  * http://bugs.php.net/bug.php?id=33898
3258  *
3259  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3260  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3261  *
3262  * @param string $path
3263  * @param string $suffix String to remove if present
3264  * @return string
3265  */
3266 function wfBaseName( $path, $suffix = '' ) {
3267         if ( $suffix == '' ) {
3268                 $encSuffix = '';
3269         } else {
3270                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3271         }
3272
3273         $matches = array();
3274         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3275                 return $matches[1];
3276         } else {
3277                 return '';
3278         }
3279 }
3280
3281 /**
3282  * Generate a relative path name to the given file.
3283  * May explode on non-matching case-insensitive paths,
3284  * funky symlinks, etc.
3285  *
3286  * @param string $path Absolute destination path including target filename
3287  * @param string $from Absolute source path, directory only
3288  * @return string
3289  */
3290 function wfRelativePath( $path, $from ) {
3291         // Normalize mixed input on Windows...
3292         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3293         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3294
3295         // Trim trailing slashes -- fix for drive root
3296         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3297         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3298
3299         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3300         $against = explode( DIRECTORY_SEPARATOR, $from );
3301
3302         if ( $pieces[0] !== $against[0] ) {
3303                 // Non-matching Windows drive letters?
3304                 // Return a full path.
3305                 return $path;
3306         }
3307
3308         // Trim off common prefix
3309         while ( count( $pieces ) && count( $against )
3310                 && $pieces[0] == $against[0] ) {
3311                 array_shift( $pieces );
3312                 array_shift( $against );
3313         }
3314
3315         // relative dots to bump us to the parent
3316         while ( count( $against ) ) {
3317                 array_unshift( $pieces, '..' );
3318                 array_shift( $against );
3319         }
3320
3321         array_push( $pieces, wfBaseName( $path ) );
3322
3323         return implode( DIRECTORY_SEPARATOR, $pieces );
3324 }
3325
3326 /**
3327  * Convert an arbitrarily-long digit string from one numeric base
3328  * to another, optionally zero-padding to a minimum column width.
3329  *
3330  * Supports base 2 through 36; digit values 10-36 are represented
3331  * as lowercase letters a-z. Input is case-insensitive.
3332  *
3333  * @param string $input Input number
3334  * @param int $sourceBase Base of the input number
3335  * @param int $destBase Desired base of the output
3336  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3337  * @param bool $lowercase Whether to output in lowercase or uppercase
3338  * @param string $engine Either "gmp", "bcmath", or "php"
3339  * @return string|bool The output number as a string, or false on error
3340  */
3341 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3342         $lowercase = true, $engine = 'auto'
3343 ) {
3344         return Wikimedia\base_convert( $input, $sourceBase, $destBase, $pad, $lowercase, $engine );
3345 }
3346
3347 /**
3348  * Check if there is sufficient entropy in php's built-in session generation
3349  *
3350  * @return bool True = there is sufficient entropy
3351  */
3352 function wfCheckEntropy() {
3353         return (
3354                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3355                         || ini_get( 'session.entropy_file' )
3356                 )
3357                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3358 }
3359
3360 /**
3361  * Override session_id before session startup if php's built-in
3362  * session generation code is not secure.
3363  */
3364 function wfFixSessionID() {
3365         // If the cookie or session id is already set we already have a session and should abort
3366         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3367                 return;
3368         }
3369
3370         // PHP's built-in session entropy is enabled if:
3371         // - entropy_file is set or you're on Windows with php 5.3.3+
3372         // - AND entropy_length is > 0
3373         // We treat it as disabled if it doesn't have an entropy length of at least 32
3374         $entropyEnabled = wfCheckEntropy();
3375
3376         // If built-in entropy is not enabled or not sufficient override PHP's
3377         // built in session id generation code
3378         if ( !$entropyEnabled ) {
3379                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3380                         "overriding session id generation using our cryptrand source.\n" );
3381                 session_id( MWCryptRand::generateHex( 32 ) );
3382         }
3383 }
3384
3385 /**
3386  * Reset the session_id
3387  *
3388  * @since 1.22
3389  */
3390 function wfResetSessionID() {
3391         global $wgCookieSecure;
3392         $oldSessionId = session_id();
3393         $cookieParams = session_get_cookie_params();
3394         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3395                 session_regenerate_id( false );
3396         } else {
3397                 $tmp = $_SESSION;
3398                 session_destroy();
3399                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3400                 $_SESSION = $tmp;
3401         }
3402         $newSessionId = session_id();
3403 }
3404
3405 /**
3406  * Initialise php session
3407  *
3408  * @param bool $sessionId
3409  */
3410 function wfSetupSession( $sessionId = false ) {
3411         global $wgSessionsInObjectCache, $wgSessionHandler;
3412         global $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly;
3413
3414         if ( $wgSessionsInObjectCache ) {
3415                 ObjectCacheSessionHandler::install();
3416         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3417                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3418                 # hasn't already been set to the desired value (that causes errors)
3419                 ini_set( 'session.save_handler', $wgSessionHandler );
3420         }
3421
3422         session_set_cookie_params(
3423                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3424         session_cache_limiter( 'private, must-revalidate' );
3425         if ( $sessionId ) {
3426                 session_id( $sessionId );
3427         } else {
3428                 wfFixSessionID();
3429         }
3430
3431         MediaWiki\suppressWarnings();
3432         session_start();
3433         MediaWiki\restoreWarnings();
3434
3435         if ( $wgSessionsInObjectCache ) {
3436                 ObjectCacheSessionHandler::renewCurrentSession();
3437         }
3438 }
3439
3440 /**
3441  * Get an object from the precompiled serialized directory
3442  *
3443  * @param string $name
3444  * @return mixed The variable on success, false on failure
3445  */
3446 function wfGetPrecompiledData( $name ) {
3447         global $IP;
3448
3449         $file = "$IP/serialized/$name";
3450         if ( file_exists( $file ) ) {
3451                 $blob = file_get_contents( $file );
3452                 if ( $blob ) {
3453                         return unserialize( $blob );
3454                 }
3455         }
3456         return false;
3457 }
3458
3459 /**
3460  * Make a cache key for the local wiki.
3461  *
3462  * @param string $args,...
3463  * @return string
3464  */
3465 function wfMemcKey( /*...*/ ) {
3466         return call_user_func_array(
3467                 array( ObjectCache::getLocalClusterInstance(), 'makeKey' ),
3468                 func_get_args()
3469         );
3470 }
3471
3472 /**
3473  * Make a cache key for a foreign DB.
3474  *
3475  * Must match what wfMemcKey() would produce in context of the foreign wiki.
3476  *
3477  * @param string $db
3478  * @param string $prefix
3479  * @param string $args,...
3480  * @return string
3481  */
3482 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3483         $args = array_slice( func_get_args(), 2 );
3484         $keyspace = $prefix ? "$db-$prefix" : $db;
3485         return call_user_func_array(
3486                 array( ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ),
3487                 array( $keyspace, $args )
3488         );
3489 }
3490
3491 /**
3492  * Make a cache key with database-agnostic prefix.
3493  *
3494  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3495  * instead. Must have a prefix as otherwise keys that use a database name
3496  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3497  *
3498  * @since 1.26
3499  * @param string $args,...
3500  * @return string
3501  */
3502 function wfGlobalCacheKey( /*...*/ ) {
3503         return call_user_func_array(
3504                 array( ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ),
3505                 func_get_args()
3506         );
3507 }
3508
3509 /**
3510  * Get an ASCII string identifying this wiki
3511  * This is used as a prefix in memcached keys
3512  *
3513  * @return string
3514  */
3515 function wfWikiID() {
3516         global $wgDBprefix, $wgDBname;
3517         if ( $wgDBprefix ) {
3518                 return "$wgDBname-$wgDBprefix";
3519         } else {
3520                 return $wgDBname;
3521         }
3522 }
3523
3524 /**
3525  * Split a wiki ID into DB name and table prefix
3526  *
3527  * @param string $wiki
3528  *
3529  * @return array
3530  */
3531 function wfSplitWikiID( $wiki ) {
3532         $bits = explode( '-', $wiki, 2 );
3533         if ( count( $bits ) < 2 ) {
3534                 $bits[] = '';
3535         }
3536         return $bits;
3537 }
3538
3539 /**
3540  * Get a Database object.
3541  *
3542  * @param int $db Index of the connection to get. May be DB_MASTER for the
3543  *            master (for write queries), DB_SLAVE for potentially lagged read
3544  *            queries, or an integer >= 0 for a particular server.
3545  *
3546  * @param string|string[] $groups Query groups. An array of group names that this query
3547  *                belongs to. May contain a single string if the query is only
3548  *                in one group.
3549  *
3550  * @param string|bool $wiki The wiki ID, or false for the current wiki
3551  *
3552  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3553  * will always return the same object, unless the underlying connection or load
3554  * balancer is manually destroyed.
3555  *
3556  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3557  * updater to ensure that a proper database is being updated.
3558  *
3559  * @return DatabaseBase
3560  */
3561 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3562         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3563 }
3564
3565 /**
3566  * Get a load balancer object.
3567  *
3568  * @param string|bool $wiki Wiki ID, or false for the current wiki
3569  * @return LoadBalancer
3570  */
3571 function wfGetLB( $wiki = false ) {
3572         return wfGetLBFactory()->getMainLB( $wiki );
3573 }
3574
3575 /**
3576  * Get the load balancer factory object
3577  *
3578  * @return LBFactory
3579  */
3580 function wfGetLBFactory() {
3581         return LBFactory::singleton();
3582 }
3583
3584 /**
3585  * Find a file.
3586  * Shortcut for RepoGroup::singleton()->findFile()
3587  *
3588  * @param string $title String or Title object
3589  * @param array $options Associative array of options (see RepoGroup::findFile)
3590  * @return File|bool File, or false if the file does not exist
3591  */
3592 function wfFindFile( $title, $options = array() ) {
3593         return RepoGroup::singleton()->findFile( $title, $options );
3594 }
3595
3596 /**
3597  * Get an object referring to a locally registered file.
3598  * Returns a valid placeholder object if the file does not exist.
3599  *
3600  * @param Title|string $title
3601  * @return LocalFile|null A File, or null if passed an invalid Title
3602  */
3603 function wfLocalFile( $title ) {
3604         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3605 }
3606
3607 /**
3608  * Should low-performance queries be disabled?
3609  *
3610  * @return bool
3611  * @codeCoverageIgnore
3612  */
3613 function wfQueriesMustScale() {
3614         global $wgMiserMode;
3615         return $wgMiserMode
3616                 || ( SiteStats::pages() > 100000
3617                 && SiteStats::edits() > 1000000
3618                 && SiteStats::users() > 10000 );
3619 }
3620
3621 /**
3622  * Get the path to a specified script file, respecting file
3623  * extensions; this is a wrapper around $wgScriptPath etc.
3624  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3625  *
3626  * @param string $script Script filename, sans extension
3627  * @return string
3628  */
3629 function wfScript( $script = 'index' ) {
3630         global $wgScriptPath, $wgScript, $wgLoadScript;
3631         if ( $script === 'index' ) {
3632                 return $wgScript;
3633         } elseif ( $script === 'load' ) {
3634                 return $wgLoadScript;
3635         } else {
3636                 return "{$wgScriptPath}/{$script}.php";
3637         }
3638 }
3639
3640 /**
3641  * Get the script URL.
3642  *
3643  * @return string Script URL
3644  */
3645 function wfGetScriptUrl() {
3646         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3647                 /* as it was called, minus the query string.
3648                  *
3649                  * Some sites use Apache rewrite rules to handle subdomains,
3650                  * and have PHP set up in a weird way that causes PHP_SELF
3651                  * to contain the rewritten URL instead of the one that the
3652                  * outside world sees.
3653                  *
3654                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
3655                  * provides containing the "before" URL.
3656                  */
3657                 return $_SERVER['SCRIPT_NAME'];
3658         } else {
3659                 return $_SERVER['URL'];
3660         }
3661 }
3662
3663 /**
3664  * Convenience function converts boolean values into "true"
3665  * or "false" (string) values
3666  *
3667  * @param bool $value
3668  * @return string
3669  */
3670 function wfBoolToStr( $value ) {
3671         return $value ? 'true' : 'false';
3672 }
3673
3674 /**
3675  * Get a platform-independent path to the null file, e.g. /dev/null
3676  *
3677  * @return string
3678  */
3679 function wfGetNull() {
3680         return wfIsWindows() ? 'NUL' : '/dev/null';
3681 }
3682
3683 /**
3684  * Waits for the slaves to catch up to the master position
3685  *
3686  * Use this when updating very large numbers of rows, as in maintenance scripts,
3687  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3688  *
3689  * By default this waits on the main DB cluster of the current wiki.
3690  * If $cluster is set to "*" it will wait on all DB clusters, including
3691  * external ones. If the lag being waiting on is caused by the code that
3692  * does this check, it makes since to use $ifWritesSince, particularly if
3693  * cluster is "*", to avoid excess overhead.
3694  *
3695  * Never call this function after a big DB write that is still in a transaction.
3696  * This only makes sense after the possible lag inducing changes were committed.
3697  *
3698  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3699  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3700  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3701  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3702  * @return bool Success (able to connect and no timeouts reached)
3703  */
3704 function wfWaitForSlaves(
3705         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3706 ) {
3707         // B/C: first argument used to be "max seconds of lag"; ignore such values
3708         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3709
3710         if ( $timeout === null ) {
3711                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3712         }
3713
3714         // Figure out which clusters need to be checked
3715         /** @var LoadBalancer[] $lbs */
3716         $lbs = array();
3717         if ( $cluster === '*' ) {
3718                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3719                         $lbs[] = $lb;
3720                 } );
3721         } elseif ( $cluster !== false ) {
3722                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3723         } else {
3724                 $lbs[] = wfGetLB( $wiki );
3725         }
3726
3727         // Get all the master positions of applicable DBs right now.
3728         // This can be faster since waiting on one cluster reduces the
3729         // time needed to wait on the next clusters.
3730         $masterPositions = array_fill( 0, count( $lbs ), false );
3731         foreach ( $lbs as $i => $lb ) {
3732                 if ( $lb->getServerCount() <= 1 ) {
3733                         // Bug 27975 - Don't try to wait for slaves if there are none
3734                         // Prevents permission error when getting master position
3735                         continue;
3736                 } elseif ( $ifWritesSince && $lb->lastMasterChangeTimestamp() < $ifWritesSince ) {
3737                         continue; // no writes since the last wait
3738                 }
3739                 $masterPositions[$i] = $lb->getMasterPos();
3740         }
3741
3742         $ok = true;
3743         foreach ( $lbs as $i => $lb ) {
3744                 if ( $masterPositions[$i] ) {
3745                         // The DBMS may not support getMasterPos() or the whole
3746                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3747                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3748                 }
3749         }
3750
3751         return $ok;
3752 }
3753
3754 /**
3755  * Count down from $seconds to zero on the terminal, with a one-second pause
3756  * between showing each number. For use in command-line scripts.
3757  *
3758  * @codeCoverageIgnore
3759  * @param int $seconds
3760  */
3761 function wfCountDown( $seconds ) {
3762         for ( $i = $seconds; $i >= 0; $i-- ) {
3763                 if ( $i != $seconds ) {
3764                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3765                 }
3766                 echo $i;
3767                 flush();
3768                 if ( $i ) {
3769                         sleep( 1 );
3770                 }
3771         }
3772         echo "\n";
3773 }
3774
3775 /**
3776  * Replace all invalid characters with -
3777  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3778  * By default, $wgIllegalFileChars = ':'
3779  *
3780  * @param string $name Filename to process
3781  * @return string
3782  */
3783 function wfStripIllegalFilenameChars( $name ) {
3784         global $wgIllegalFileChars;
3785         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3786         $name = wfBaseName( $name );
3787         $name = preg_replace(
3788                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3789                 '-',
3790                 $name
3791         );
3792         return $name;
3793 }
3794
3795 /**
3796  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3797  *
3798  * @return int Resulting value of the memory limit.
3799  */
3800 function wfMemoryLimit() {
3801         global $wgMemoryLimit;
3802         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3803         if ( $memlimit != -1 ) {
3804                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3805                 if ( $conflimit == -1 ) {
3806                         wfDebug( "Removing PHP's memory limit\n" );
3807                         MediaWiki\suppressWarnings();
3808                         ini_set( 'memory_limit', $conflimit );
3809                         MediaWiki\restoreWarnings();
3810                         return $conflimit;
3811                 } elseif ( $conflimit > $memlimit ) {
3812                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3813                         MediaWiki\suppressWarnings();
3814                         ini_set( 'memory_limit', $conflimit );
3815                         MediaWiki\restoreWarnings();
3816                         return $conflimit;
3817                 }
3818         }
3819         return $memlimit;
3820 }
3821
3822 /**
3823  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3824  *
3825  * @return int Prior time limit
3826  * @since 1.26
3827  */
3828 function wfTransactionalTimeLimit() {
3829         global $wgTransactionalTimeLimit;
3830
3831         $timeLimit = ini_get( 'max_execution_time' );
3832         // Note that CLI scripts use 0
3833         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3834                 set_time_limit( $wgTransactionalTimeLimit );
3835         }
3836
3837         ignore_user_abort( true ); // ignore client disconnects
3838
3839         return $timeLimit;
3840 }
3841
3842 /**
3843  * Converts shorthand byte notation to integer form
3844  *
3845  * @param string $string
3846  * @param int $default Returned if $string is empty
3847  * @return int
3848  */
3849 function wfShorthandToInteger( $string = '', $default = -1 ) {
3850         $string = trim( $string );
3851         if ( $string === '' ) {
3852                 return $default;
3853         }
3854         $last = $string[strlen( $string ) - 1];
3855         $val = intval( $string );
3856         switch ( $last ) {
3857                 case 'g':
3858                 case 'G':
3859                         $val *= 1024;
3860                         // break intentionally missing
3861                 case 'm':
3862                 case 'M':
3863                         $val *= 1024;
3864                         // break intentionally missing
3865                 case 'k':
3866                 case 'K':
3867                         $val *= 1024;
3868         }
3869
3870         return $val;
3871 }
3872
3873 /**
3874  * Get the normalised IETF language tag
3875  * See unit test for examples.
3876  *
3877  * @param string $code The language code.
3878  * @return string The language code which complying with BCP 47 standards.
3879  */
3880 function wfBCP47( $code ) {
3881         $codeSegment = explode( '-', $code );
3882         $codeBCP = array();
3883         foreach ( $codeSegment as $segNo => $seg ) {
3884                 // when previous segment is x, it is a private segment and should be lc
3885                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3886                         $codeBCP[$segNo] = strtolower( $seg );
3887                 // ISO 3166 country code
3888                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3889                         $codeBCP[$segNo] = strtoupper( $seg );
3890                 // ISO 15924 script code
3891                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3892                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3893                 // Use lowercase for other cases
3894                 } else {
3895                         $codeBCP[$segNo] = strtolower( $seg );
3896                 }
3897         }
3898         $langCode = implode( '-', $codeBCP );
3899         return $langCode;
3900 }
3901
3902 /**
3903  * Get a specific cache object.
3904  *
3905  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3906  * @return BagOStuff
3907  */
3908 function wfGetCache( $cacheType ) {
3909         return ObjectCache::getInstance( $cacheType );
3910 }
3911
3912 /**
3913  * Get the main cache object
3914  *
3915  * @return BagOStuff
3916  */
3917 function wfGetMainCache() {
3918         global $wgMainCacheType;
3919         return ObjectCache::getInstance( $wgMainCacheType );
3920 }
3921
3922 /**
3923  * Get the cache object used by the message cache
3924  *
3925  * @return BagOStuff
3926  */
3927 function wfGetMessageCacheStorage() {
3928         global $wgMessageCacheType;
3929         return ObjectCache::getInstance( $wgMessageCacheType );
3930 }
3931
3932 /**
3933  * Get the cache object used by the parser cache
3934  *
3935  * @return BagOStuff
3936  */
3937 function wfGetParserCacheStorage() {
3938         global $wgParserCacheType;
3939         return ObjectCache::getInstance( $wgParserCacheType );
3940 }
3941
3942 /**
3943  * Call hook functions defined in $wgHooks
3944  *
3945  * @param string $event Event name
3946  * @param array $args Parameters passed to hook functions
3947  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3948  *
3949  * @return bool True if no handler aborted the hook
3950  * @deprecated 1.25 - use Hooks::run
3951  */
3952 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3953         return Hooks::run( $event, $args, $deprecatedVersion );
3954 }
3955
3956 /**
3957  * Wrapper around php's unpack.
3958  *
3959  * @param string $format The format string (See php's docs)
3960  * @param string $data A binary string of binary data
3961  * @param int|bool $length The minimum length of $data or false. This is to
3962  *      prevent reading beyond the end of $data. false to disable the check.
3963  *
3964  * Also be careful when using this function to read unsigned 32 bit integer
3965  * because php might make it negative.
3966  *
3967  * @throws MWException If $data not long enough, or if unpack fails
3968  * @return array Associative array of the extracted data
3969  */
3970 function wfUnpack( $format, $data, $length = false ) {
3971         if ( $length !== false ) {
3972                 $realLen = strlen( $data );
3973                 if ( $realLen < $length ) {
3974                         throw new MWException( "Tried to use wfUnpack on a "
3975                                 . "string of length $realLen, but needed one "
3976                                 . "of at least length $length."
3977                         );
3978                 }
3979         }
3980
3981         MediaWiki\suppressWarnings();
3982         $result = unpack( $format, $data );
3983         MediaWiki\restoreWarnings();
3984
3985         if ( $result === false ) {
3986                 // If it cannot extract the packed data.
3987                 throw new MWException( "unpack could not unpack binary data" );
3988         }
3989         return $result;
3990 }
3991
3992 /**
3993  * Determine if an image exists on the 'bad image list'.
3994  *
3995  * The format of MediaWiki:Bad_image_list is as follows:
3996  *    * Only list items (lines starting with "*") are considered
3997  *    * The first link on a line must be a link to a bad image
3998  *    * Any subsequent links on the same line are considered to be exceptions,
3999  *      i.e. articles where the image may occur inline.
4000  *
4001  * @param string $name The image name to check
4002  * @param Title|bool $contextTitle The page on which the image occurs, if known
4003  * @param string $blacklist Wikitext of a file blacklist
4004  * @return bool
4005  */
4006 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4007         # Handle redirects; callers almost always hit wfFindFile() anyway,
4008         # so just use that method because it has a fast process cache.
4009         $file = wfFindFile( $name ); // get the final name
4010         $name = $file ? $file->getTitle()->getDBkey() : $name;
4011
4012         # Run the extension hook
4013         $bad = false;
4014         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4015                 return $bad;
4016         }
4017
4018         $cache = ObjectCache::getLocalServerInstance( 'hash' );
4019         $key = wfMemcKey( 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist ) );
4020         $badImages = $cache->get( $key );
4021
4022         if ( $badImages === false ) { // cache miss
4023                 if ( $blacklist === null ) {
4024                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4025                 }
4026                 # Build the list now
4027                 $badImages = array();
4028                 $lines = explode( "\n", $blacklist );
4029                 foreach ( $lines as $line ) {
4030                         # List items only
4031                         if ( substr( $line, 0, 1 ) !== '*' ) {
4032                                 continue;
4033                         }
4034
4035                         # Find all links
4036                         $m = array();
4037                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4038                                 continue;
4039                         }
4040
4041                         $exceptions = array();
4042                         $imageDBkey = false;
4043                         foreach ( $m[1] as $i => $titleText ) {
4044                                 $title = Title::newFromText( $titleText );
4045                                 if ( !is_null( $title ) ) {
4046                                         if ( $i == 0 ) {
4047                                                 $imageDBkey = $title->getDBkey();
4048                                         } else {
4049                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4050                                         }
4051                                 }
4052                         }
4053
4054                         if ( $imageDBkey !== false ) {
4055                                 $badImages[$imageDBkey] = $exceptions;
4056                         }
4057                 }
4058                 $cache->set( $key, $badImages, 60 );
4059         }
4060
4061         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4062         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4063
4064         return $bad;
4065 }
4066
4067 /**
4068  * Determine whether the client at a given source IP is likely to be able to
4069  * access the wiki via HTTPS.
4070  *
4071  * @param string $ip The IPv4/6 address in the normal human-readable form
4072  * @return bool
4073  */
4074 function wfCanIPUseHTTPS( $ip ) {
4075         $canDo = true;
4076         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4077         return !!$canDo;
4078 }
4079
4080 /**
4081  * Determine input string is represents as infinity
4082  *
4083  * @param string $str The string to determine
4084  * @return bool
4085  * @since 1.25
4086  */
4087 function wfIsInfinity( $str ) {
4088         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4089         return in_array( $str, $infinityValues );
4090 }
4091
4092 /**
4093  * Work out the IP address based on various globals
4094  * For trusted proxies, use the XFF client IP (first of the chain)
4095  *
4096  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4097  * @return string
4098  */
4099 function wfGetIP() {
4100         wfDeprecated( __METHOD__, '1.19' );
4101         global $wgRequest;
4102         return $wgRequest->getIP();
4103 }
4104
4105 /**
4106  * Checks if an IP is a trusted proxy provider.
4107  * Useful to tell if X-Forwarded-For data is possibly bogus.
4108  * Squid cache servers for the site are whitelisted.
4109  * @deprecated Since 1.24, use IP::isTrustedProxy()
4110  *
4111  * @param string $ip
4112  * @return bool
4113  */
4114 function wfIsTrustedProxy( $ip ) {
4115         wfDeprecated( __METHOD__, '1.24' );
4116         return IP::isTrustedProxy( $ip );
4117 }
4118
4119 /**
4120  * Checks if an IP matches a proxy we've configured.
4121  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4122  *
4123  * @param string $ip
4124  * @return bool
4125  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4126  */
4127 function wfIsConfiguredProxy( $ip ) {
4128         wfDeprecated( __METHOD__, '1.24' );
4129         return IP::isConfiguredProxy( $ip );
4130 }
4131
4132 /**
4133  * Returns true if these thumbnail parameters match one that MediaWiki
4134  * requests from file description pages and/or parser output.
4135  *
4136  * $params is considered non-standard if they involve a non-standard
4137  * width or any non-default parameters aside from width and page number.
4138  * The number of possible files with standard parameters is far less than
4139  * that of all combinations; rate-limiting for them can thus be more generious.
4140  *
4141  * @param File $file
4142  * @param array $params
4143  * @return bool
4144  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4145  */
4146 function wfThumbIsStandard( File $file, array $params ) {
4147         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4148
4149         $multipliers = array( 1 );
4150         if ( $wgResponsiveImages ) {
4151                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4152                 // @see Linker::processResponsiveImages
4153                 $multipliers[] = 1.5;
4154                 $multipliers[] = 2;
4155         }
4156
4157         $handler = $file->getHandler();
4158         if ( !$handler || !isset( $params['width'] ) ) {
4159                 return false;
4160         }
4161
4162         $basicParams = array();
4163         if ( isset( $params['page'] ) ) {
4164                 $basicParams['page'] = $params['page'];
4165         }
4166
4167         $thumbLimits = array();
4168         $imageLimits = array();
4169         // Expand limits to account for multipliers
4170         foreach ( $multipliers as $multiplier ) {
4171                 $thumbLimits = array_merge( $thumbLimits, array_map(
4172                         function ( $width ) use ( $multiplier ) {
4173                                 return round( $width * $multiplier );
4174                         }, $wgThumbLimits )
4175                 );
4176                 $imageLimits = array_merge( $imageLimits, array_map(
4177                         function ( $pair ) use ( $multiplier ) {
4178                                 return array(
4179                                         round( $pair[0] * $multiplier ),
4180                                         round( $pair[1] * $multiplier ),
4181                                 );
4182                         }, $wgImageLimits )
4183                 );
4184         }
4185
4186         // Check if the width matches one of $wgThumbLimits
4187         if ( in_array( $params['width'], $thumbLimits ) ) {
4188                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4189                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4190                 $handler->normaliseParams( $file, $normalParams );
4191         } else {
4192                 // If not, then check if the width matchs one of $wgImageLimits
4193                 $match = false;
4194                 foreach ( $imageLimits as $pair ) {
4195                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4196                         // Decide whether the thumbnail should be scaled on width or height.
4197                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4198                         $handler->normaliseParams( $file, $normalParams );
4199                         // Check if this standard thumbnail size maps to the given width
4200                         if ( $normalParams['width'] == $params['width'] ) {
4201                                 $match = true;
4202                                 break;
4203                         }
4204                 }
4205                 if ( !$match ) {
4206                         return false; // not standard for description pages
4207                 }
4208         }
4209
4210         // Check that the given values for non-page, non-width, params are just defaults
4211         foreach ( $params as $key => $value ) {
4212                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4213                         return false;
4214                 }
4215         }
4216
4217         return true;
4218 }
4219
4220 /**
4221  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
4222  *
4223  * Values that exist in both values will be combined with += (all values of the array
4224  * of $newValues will be added to the values of the array of $baseArray, while values,
4225  * that exists in both, the value of $baseArray will be used).
4226  *
4227  * @param array $baseArray The array where you want to add the values of $newValues to
4228  * @param array $newValues An array with new values
4229  * @return array The combined array
4230  * @since 1.26
4231  */
4232 function wfArrayPlus2d( array $baseArray, array $newValues ) {
4233         // First merge items that are in both arrays
4234         foreach ( $baseArray as $name => &$groupVal ) {
4235                 if ( isset( $newValues[$name] ) ) {
4236                         $groupVal += $newValues[$name];
4237                 }
4238         }
4239         // Now add items that didn't exist yet
4240         $baseArray += $newValues;
4241
4242         return $baseArray;
4243 }