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                         # @todo FIXME: Sometimes get nested arrays for $params,
 312                         # which leads to E_NOTICEs
 313                         $spec = implode( "\t", $params );
 314                         $out[$spec] = $params;
 315                 }
 316         }
 317         return array_values( $out );
 318 }
 319
 320 /**
 321  * Insert array into another array after the specified *KEY*
 322  *
 323  * @param array $array The array.
 324  * @param array $insert The array to insert.
 325  * @param mixed $after The key to insert after
 326  * @return array
 327  */
 328 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 329         // Find the offset of the element to insert after.
 330         $keys = array_keys( $array );
 331         $offsetByKey = array_flip( $keys );
 332
 333         $offset = $offsetByKey[$after];
 334
 335         // Insert at the specified offset
 336         $before = array_slice( $array, 0, $offset + 1, true );
 337         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 338
 339         $output = $before + $insert + $after;
 340
 341         return $output;
 342 }
 343
 344 /**
 345  * Recursively converts the parameter (an object) to an array with the same data
 346  *
 347  * @param object|array $objOrArray
 348  * @param bool $recursive
 349  * @return array
 350  */
 351 function wfObjectToArray( $objOrArray, $recursive = true ) {
 352         $array = array();
 353         if ( is_object( $objOrArray ) ) {
 354                 $objOrArray = get_object_vars( $objOrArray );
 355         }
 356         foreach ( $objOrArray as $key => $value ) {
 357                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 358                         $value = wfObjectToArray( $value );
 359                 }
 360
 361                 $array[$key] = $value;
 362         }
 363
 364         return $array;
 365 }
 366
 367 /**
 368  * Get a random decimal value between 0 and 1, in a way
 369  * not likely to give duplicate values for any realistic
 370  * number of articles.
 371  *
 372  * @return string
 373  */
 374 function wfRandom() {
 375         # The maximum random value is "only" 2^31-1, so get two random
 376         # values to reduce the chance of dupes
 377         $max = mt_getrandmax() + 1;
 378         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 379
 380         return $rand;
 381 }
 382
 383 /**
 384  * Get a random string containing a number of pseudo-random hex
 385  * characters.
 386  * @note This is not secure, if you are trying to generate some sort
 387  *       of token please use MWCryptRand instead.
 388  *
 389  * @param int $length The length of the string to generate
 390  * @return string
 391  * @since 1.20
 392  */
 393 function wfRandomString( $length = 32 ) {
 394         $str = '';
 395         for ( $n = 0; $n < $length; $n += 7 ) {
 396                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 397         }
 398         return substr( $str, 0, $length );
 399 }
 400
 401 /**
 402  * We want some things to be included as literal characters in our title URLs
 403  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 404  * all of the following should be safe:
 405  *
 406  * ;:@&=$-_.+!*'(),
 407  *
 408  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 409  * character which should not be encoded. More importantly, google chrome
 410  * always converts %7E back to ~, and converting it in this function can
 411  * cause a redirect loop (T105265).
 412  *
 413  * But + is not safe because it's used to indicate a space; &= are only safe in
 414  * paths and not in queries (and we don't distinguish here); ' seems kind of
 415  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 416  * is reserved, we don't care.  So the list we unescape is:
 417  *
 418  * ;:@$!*(),/~
 419  *
 420  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 421  * so no fancy : for IIS7.
 422  *
 423  * %2F in the page titles seems to fatally break for some reason.
 424  *
 425  * @param string $s
 426  * @return string
 427  */
 428 function wfUrlencode( $s ) {
 429         static $needle;
 430
 431         if ( is_null( $s ) ) {
 432                 $needle = null;
 433                 return '';
 434         }
 435
 436         if ( is_null( $needle ) ) {
 437                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' );
 438                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 439                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 440                 ) {
 441                         $needle[] = '%3A';
 442                 }
 443         }
 444
 445         $s = urlencode( $s );
 446         $s = str_ireplace(
 447                 $needle,
 448                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ),
 449                 $s
 450         );
 451
 452         return $s;
 453 }
 454
 455 /**
 456  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 457  * "days=7&limit=100". Options in the first array override options in the second.
 458  * Options set to null or false will not be output.
 459  *
 460  * @param array $array1 ( String|Array )
 461  * @param array $array2 ( String|Array )
 462  * @param string $prefix
 463  * @return string
 464  */
 465 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 466         if ( !is_null( $array2 ) ) {
 467                 $array1 = $array1 + $array2;
 468         }
 469
 470         $cgi = '';
 471         foreach ( $array1 as $key => $value ) {
 472                 if ( !is_null( $value ) && $value !== false ) {
 473                         if ( $cgi != '' ) {
 474                                 $cgi .= '&';
 475                         }
 476                         if ( $prefix !== '' ) {
 477                                 $key = $prefix . "[$key]";
 478                         }
 479                         if ( is_array( $value ) ) {
 480                                 $firstTime = true;
 481                                 foreach ( $value as $k => $v ) {
 482                                         $cgi .= $firstTime ? '' : '&';
 483                                         if ( is_array( $v ) ) {
 484                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 485                                         } else {
 486                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 487                                         }
 488                                         $firstTime = false;
 489                                 }
 490                         } else {
 491                                 if ( is_object( $value ) ) {
 492                                         $value = $value->__toString();
 493                                 }
 494                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 495                         }
 496                 }
 497         }
 498         return $cgi;
 499 }
 500
 501 /**
 502  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 503  * its argument and returns the same string in array form.  This allows compatibility
 504  * with legacy functions that accept raw query strings instead of nice
 505  * arrays.  Of course, keys and values are urldecode()d.
 506  *
 507  * @param string $query Query string
 508  * @return string[] Array version of input
 509  */
 510 function wfCgiToArray( $query ) {
 511         if ( isset( $query[0] ) && $query[0] == '?' ) {
 512                 $query = substr( $query, 1 );
 513         }
 514         $bits = explode( '&', $query );
 515         $ret = array();
 516         foreach ( $bits as $bit ) {
 517                 if ( $bit === '' ) {
 518                         continue;
 519                 }
 520                 if ( strpos( $bit, '=' ) === false ) {
 521                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 522                         $key = $bit;
 523                         $value = '';
 524                 } else {
 525                         list( $key, $value ) = explode( '=', $bit );
 526                 }
 527                 $key = urldecode( $key );
 528                 $value = urldecode( $value );
 529                 if ( strpos( $key, '[' ) !== false ) {
 530                         $keys = array_reverse( explode( '[', $key ) );
 531                         $key = array_pop( $keys );
 532                         $temp = $value;
 533                         foreach ( $keys as $k ) {
 534                                 $k = substr( $k, 0, -1 );
 535                                 $temp = array( $k => $temp );
 536                         }
 537                         if ( isset( $ret[$key] ) ) {
 538                                 $ret[$key] = array_merge( $ret[$key], $temp );
 539                         } else {
 540                                 $ret[$key] = $temp;
 541                         }
 542                 } else {
 543                         $ret[$key] = $value;
 544                 }
 545         }
 546         return $ret;
 547 }
 548
 549 /**
 550  * Append a query string to an existing URL, which may or may not already
 551  * have query string parameters already. If so, they will be combined.
 552  *
 553  * @param string $url
 554  * @param string|string[] $query String or associative array
 555  * @return string
 556  */
 557 function wfAppendQuery( $url, $query ) {
 558         if ( is_array( $query ) ) {
 559                 $query = wfArrayToCgi( $query );
 560         }
 561         if ( $query != '' ) {
 562                 if ( false === strpos( $url, '?' ) ) {
 563                         $url .= '?';
 564                 } else {
 565                         $url .= '&';
 566                 }
 567                 $url .= $query;
 568         }
 569         return $url;
 570 }
 571
 572 /**
 573  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 574  * is correct.
 575  *
 576  * The meaning of the PROTO_* constants is as follows:
 577  * PROTO_HTTP: Output a URL starting with http://
 578  * PROTO_HTTPS: Output a URL starting with https://
 579  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 580  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 581  *    on which protocol was used for the current incoming request
 582  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 583  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 584  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 585  *
 586  * @todo this won't work with current-path-relative URLs
 587  * like "subdir/foo.html", etc.
 588  *
 589  * @param string $url Either fully-qualified or a local path + query
 590  * @param string $defaultProto One of the PROTO_* constants. Determines the
 591  *    protocol to use if $url or $wgServer is protocol-relative
 592  * @return string Fully-qualified URL, current-path-relative URL or false if
 593  *    no valid URL can be constructed
 594  */
 595 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 596         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 597                 $wgHttpsPort;
 598         if ( $defaultProto === PROTO_CANONICAL ) {
 599                 $serverUrl = $wgCanonicalServer;
 600         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 601                 // Make $wgInternalServer fall back to $wgServer if not set
 602                 $serverUrl = $wgInternalServer;
 603         } else {
 604                 $serverUrl = $wgServer;
 605                 if ( $defaultProto === PROTO_CURRENT ) {
 606                         $defaultProto = $wgRequest->getProtocol() . '://';
 607                 }
 608         }
 609
 610         // Analyze $serverUrl to obtain its protocol
 611         $bits = wfParseUrl( $serverUrl );
 612         $serverHasProto = $bits && $bits['scheme'] != '';
 613
 614         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 615                 if ( $serverHasProto ) {
 616                         $defaultProto = $bits['scheme'] . '://';
 617                 } else {
 618                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 619                         // This really isn't supposed to happen. Fall back to HTTP in this
 620                         // ridiculous case.
 621                         $defaultProto = PROTO_HTTP;
 622                 }
 623         }
 624
 625         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 626
 627         if ( substr( $url, 0, 2 ) == '//' ) {
 628                 $url = $defaultProtoWithoutSlashes . $url;
 629         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 630                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 631                 // otherwise leave it alone.
 632                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 633         }
 634
 635         $bits = wfParseUrl( $url );
 636
 637         // ensure proper port for HTTPS arrives in URL
 638         // https://phabricator.wikimedia.org/T67184
 639         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 640                 $bits['port'] = $wgHttpsPort;
 641         }
 642
 643         if ( $bits && isset( $bits['path'] ) ) {
 644                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 645                 return wfAssembleUrl( $bits );
 646         } elseif ( $bits ) {
 647                 # No path to expand
 648                 return $url;
 649         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 650                 # URL is a relative path
 651                 return wfRemoveDotSegments( $url );
 652         }
 653
 654         # Expanded URL is not valid.
 655         return false;
 656 }
 657
 658 /**
 659  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 660  * if you need to edit part of a URL and put it back together.
 661  *
 662  * This is the basic structure used (brackets contain keys for $urlParts):
 663  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 664  *
 665  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 666  *
 667  * @since 1.19
 668  * @param array $urlParts URL parts, as output from wfParseUrl
 669  * @return string URL assembled from its component parts
 670  */
 671 function wfAssembleUrl( $urlParts ) {
 672         $result = '';
 673
 674         if ( isset( $urlParts['delimiter'] ) ) {
 675                 if ( isset( $urlParts['scheme'] ) ) {
 676                         $result .= $urlParts['scheme'];
 677                 }
 678
 679                 $result .= $urlParts['delimiter'];
 680         }
 681
 682         if ( isset( $urlParts['host'] ) ) {
 683                 if ( isset( $urlParts['user'] ) ) {
 684                         $result .= $urlParts['user'];
 685                         if ( isset( $urlParts['pass'] ) ) {
 686                                 $result .= ':' . $urlParts['pass'];
 687                         }
 688                         $result .= '@';
 689                 }
 690
 691                 $result .= $urlParts['host'];
 692
 693                 if ( isset( $urlParts['port'] ) ) {
 694                         $result .= ':' . $urlParts['port'];
 695                 }
 696         }
 697
 698         if ( isset( $urlParts['path'] ) ) {
 699                 $result .= $urlParts['path'];
 700         }
 701
 702         if ( isset( $urlParts['query'] ) ) {
 703                 $result .= '?' . $urlParts['query'];
 704         }
 705
 706         if ( isset( $urlParts['fragment'] ) ) {
 707                 $result .= '#' . $urlParts['fragment'];
 708         }
 709
 710         return $result;
 711 }
 712
 713 /**
 714  * Remove all dot-segments in the provided URL path.  For example,
 715  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 716  * RFC3986 section 5.2.4.
 717  *
 718  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 719  *
 720  * @param string $urlPath URL path, potentially containing dot-segments
 721  * @return string URL path with all dot-segments removed
 722  */
 723 function wfRemoveDotSegments( $urlPath ) {
 724         $output = '';
 725         $inputOffset = 0;
 726         $inputLength = strlen( $urlPath );
 727
 728         while ( $inputOffset < $inputLength ) {
 729                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 730                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 731                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 732                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 733                 $trimOutput = false;
 734
 735                 if ( $prefixLengthTwo == './' ) {
 736                         # Step A, remove leading "./"
 737                         $inputOffset += 2;
 738                 } elseif ( $prefixLengthThree == '../' ) {
 739                         # Step A, remove leading "../"
 740                         $inputOffset += 3;
 741                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 742                         # Step B, replace leading "/.$" with "/"
 743                         $inputOffset += 1;
 744                         $urlPath[$inputOffset] = '/';
 745                 } elseif ( $prefixLengthThree == '/./' ) {
 746                         # Step B, replace leading "/./" with "/"
 747                         $inputOffset += 2;
 748                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 749                         # Step C, replace leading "/..$" with "/" and
 750                         # remove last path component in output
 751                         $inputOffset += 2;
 752                         $urlPath[$inputOffset] = '/';
 753                         $trimOutput = true;
 754                 } elseif ( $prefixLengthFour == '/../' ) {
 755                         # Step C, replace leading "/../" with "/" and
 756                         # remove last path component in output
 757                         $inputOffset += 3;
 758                         $trimOutput = true;
 759                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 760                         # Step D, remove "^.$"
 761                         $inputOffset += 1;
 762                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 763                         # Step D, remove "^..$"
 764                         $inputOffset += 2;
 765                 } else {
 766                         # Step E, move leading path segment to output
 767                         if ( $prefixLengthOne == '/' ) {
 768                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 769                         } else {
 770                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 771                         }
 772                         if ( $slashPos === false ) {
 773                                 $output .= substr( $urlPath, $inputOffset );
 774                                 $inputOffset = $inputLength;
 775                         } else {
 776                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 777                                 $inputOffset += $slashPos - $inputOffset;
 778                         }
 779                 }
 780
 781                 if ( $trimOutput ) {
 782                         $slashPos = strrpos( $output, '/' );
 783                         if ( $slashPos === false ) {
 784                                 $output = '';
 785                         } else {
 786                                 $output = substr( $output, 0, $slashPos );
 787                         }
 788                 }
 789         }
 790
 791         return $output;
 792 }
 793
 794 /**
 795  * Returns a regular expression of url protocols
 796  *
 797  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 798  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 799  * @return string
 800  */
 801 function wfUrlProtocols( $includeProtocolRelative = true ) {
 802         global $wgUrlProtocols;
 803
 804         // Cache return values separately based on $includeProtocolRelative
 805         static $withProtRel = null, $withoutProtRel = null;
 806         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 807         if ( !is_null( $cachedValue ) ) {
 808                 return $cachedValue;
 809         }
 810
 811         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 812         // with LocalSettings files from 1.5
 813         if ( is_array( $wgUrlProtocols ) ) {
 814                 $protocols = array();
 815                 foreach ( $wgUrlProtocols as $protocol ) {
 816                         // Filter out '//' if !$includeProtocolRelative
 817                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 818                                 $protocols[] = preg_quote( $protocol, '/' );
 819                         }
 820                 }
 821
 822                 $retval = implode( '|', $protocols );
 823         } else {
 824                 // Ignore $includeProtocolRelative in this case
 825                 // This case exists for pre-1.6 compatibility, and we can safely assume
 826                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 827                 // URLs weren't supported until 1.18
 828                 $retval = $wgUrlProtocols;
 829         }
 830
 831         // Cache return value
 832         if ( $includeProtocolRelative ) {
 833                 $withProtRel = $retval;
 834         } else {
 835                 $withoutProtRel = $retval;
 836         }
 837         return $retval;
 838 }
 839
 840 /**
 841  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 842  * you need a regex that matches all URL protocols but does not match protocol-
 843  * relative URLs
 844  * @return string
 845  */
 846 function wfUrlProtocolsWithoutProtRel() {
 847         return wfUrlProtocols( false );
 848 }
 849
 850 /**
 851  * parse_url() work-alike, but non-broken.  Differences:
 852  *
 853  * 1) Does not raise warnings on bad URLs (just returns false).
 854  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 855  *    protocol-relative URLs) correctly.
 856  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 857  *
 858  * @param string $url A URL to parse
 859  * @return string[] Bits of the URL in an associative array, per PHP docs
 860  */
 861 function wfParseUrl( $url ) {
 862         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 863
 864         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 865         // bad that the easiest way to handle them is to just prepend 'http:' and
 866         // strip the protocol out later.
 867         $wasRelative = substr( $url, 0, 2 ) == '//';
 868         if ( $wasRelative ) {
 869                 $url = "http:$url";
 870         }
 871         MediaWiki\suppressWarnings();
 872         $bits = parse_url( $url );
 873         MediaWiki\restoreWarnings();
 874         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 875         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 876         if ( !$bits || !isset( $bits['scheme'] ) ) {
 877                 return false;
 878         }
 879
 880         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 881         $bits['scheme'] = strtolower( $bits['scheme'] );
 882
 883         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 884         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 885                 $bits['delimiter'] = '://';
 886         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 887                 $bits['delimiter'] = ':';
 888                 // parse_url detects for news: and mailto: the host part of an url as path
 889                 // We have to correct this wrong detection
 890                 if ( isset( $bits['path'] ) ) {
 891                         $bits['host'] = $bits['path'];
 892                         $bits['path'] = '';
 893                 }
 894         } else {
 895                 return false;
 896         }
 897
 898         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 899         if ( !isset( $bits['host'] ) ) {
 900                 $bits['host'] = '';
 901
 902                 // bug 45069
 903                 if ( isset( $bits['path'] ) ) {
 904                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 905                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 906                                 $bits['path'] = '/' . $bits['path'];
 907                         }
 908                 } else {
 909                         $bits['path'] = '';
 910                 }
 911         }
 912
 913         // If the URL was protocol-relative, fix scheme and delimiter
 914         if ( $wasRelative ) {
 915                 $bits['scheme'] = '';
 916                 $bits['delimiter'] = '//';
 917         }
 918         return $bits;
 919 }
 920
 921 /**
 922  * Take a URL, make sure it's expanded to fully qualified, and replace any
 923  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 924  * for more compact display and legibility for local audiences.
 925  *
 926  * @todo handle punycode domains too
 927  *
 928  * @param string $url
 929  * @return string
 930  */
 931 function wfExpandIRI( $url ) {
 932         return preg_replace_callback(
 933                 '/((?:%[89A-F][0-9A-F])+)/i',
 934                 'wfExpandIRI_callback',
 935                 wfExpandUrl( $url )
 936         );
 937 }
 938
 939 /**
 940  * Private callback for wfExpandIRI
 941  * @param array $matches
 942  * @return string
 943  */
 944 function wfExpandIRI_callback( $matches ) {
 945         return urldecode( $matches[1] );
 946 }
 947
 948 /**
 949  * Make URL indexes, appropriate for the el_index field of externallinks.
 950  *
 951  * @param string $url
 952  * @return array
 953  */
 954 function wfMakeUrlIndexes( $url ) {
 955         $bits = wfParseUrl( $url );
 956
 957         // Reverse the labels in the hostname, convert to lower case
 958         // For emails reverse domainpart only
 959         if ( $bits['scheme'] == 'mailto' ) {
 960                 $mailparts = explode( '@', $bits['host'], 2 );
 961                 if ( count( $mailparts ) === 2 ) {
 962                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 963                 } else {
 964                         // No domain specified, don't mangle it
 965                         $domainpart = '';
 966                 }
 967                 $reversedHost = $domainpart . '@' . $mailparts[0];
 968         } else {
 969                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 970         }
 971         // Add an extra dot to the end
 972         // Why? Is it in wrong place in mailto links?
 973         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 974                 $reversedHost .= '.';
 975         }
 976         // Reconstruct the pseudo-URL
 977         $prot = $bits['scheme'];
 978         $index = $prot . $bits['delimiter'] . $reversedHost;
 979         // Leave out user and password. Add the port, path, query and fragment
 980         if ( isset( $bits['port'] ) ) {
 981                 $index .= ':' . $bits['port'];
 982         }
 983         if ( isset( $bits['path'] ) ) {
 984                 $index .= $bits['path'];
 985         } else {
 986                 $index .= '/';
 987         }
 988         if ( isset( $bits['query'] ) ) {
 989                 $index .= '?' . $bits['query'];
 990         }
 991         if ( isset( $bits['fragment'] ) ) {
 992                 $index .= '#' . $bits['fragment'];
 993         }
 994
 995         if ( $prot == '' ) {
 996                 return array( "http:$index", "https:$index" );
 997         } else {
 998                 return array( $index );
 999         }
1000 }
1001
1002 /**
1003  * Check whether a given URL has a domain that occurs in a given set of domains
1004  * @param string $url URL
1005  * @param array $domains Array of domains (strings)
1006  * @return bool True if the host part of $url ends in one of the strings in $domains
1007  */
1008 function wfMatchesDomainList( $url, $domains ) {
1009         $bits = wfParseUrl( $url );
1010         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1011                 $host = '.' . $bits['host'];
1012                 foreach ( (array)$domains as $domain ) {
1013                         $domain = '.' . $domain;
1014                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1015                                 return true;
1016                         }
1017                 }
1018         }
1019         return false;
1020 }
1021
1022 /**
1023  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1024  * In normal operation this is a NOP.
1025  *
1026  * Controlling globals:
1027  * $wgDebugLogFile - points to the log file
1028  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1029  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1030  *
1031  * @since 1.25 support for additional context data
1032  *
1033  * @param string $text
1034  * @param string|bool $dest Unused
1035  * @param array $context Additional logging context data
1036  */
1037 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1038         global $wgDebugRawPage, $wgDebugLogPrefix;
1039         global $wgDebugTimestamps, $wgRequestTime;
1040
1041         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1042                 return;
1043         }
1044
1045         $text = trim( $text );
1046
1047         // Inline logic from deprecated wfDebugTimer()
1048         if ( $wgDebugTimestamps ) {
1049                 $context['seconds_elapsed'] = sprintf(
1050                         '%6.4f',
1051                         microtime( true ) - $wgRequestTime
1052                 );
1053                 $context['memory_used'] = sprintf(
1054                         '%5.1fM',
1055                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1056                 );
1057         }
1058
1059         if ( $wgDebugLogPrefix !== '' ) {
1060                 $context['prefix'] = $wgDebugLogPrefix;
1061         }
1062
1063         $logger = LoggerFactory::getInstance( 'wfDebug' );
1064         $logger->debug( $text, $context );
1065 }
1066
1067 /**
1068  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1069  * @return bool
1070  */
1071 function wfIsDebugRawPage() {
1072         static $cache;
1073         if ( $cache !== null ) {
1074                 return $cache;
1075         }
1076         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1077         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1078                 || (
1079                         isset( $_SERVER['SCRIPT_NAME'] )
1080                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1081                 )
1082         ) {
1083                 $cache = true;
1084         } else {
1085                 $cache = false;
1086         }
1087         return $cache;
1088 }
1089
1090 /**
1091  * Get microsecond timestamps for debug logs
1092  *
1093  * @deprecated since 1.25
1094  * @return string
1095  */
1096 function wfDebugTimer() {
1097         global $wgDebugTimestamps, $wgRequestTime;
1098
1099         wfDeprecated( __METHOD__, '1.25' );
1100
1101         if ( !$wgDebugTimestamps ) {
1102                 return '';
1103         }
1104
1105         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1106         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1107         return "$prefix $mem  ";
1108 }
1109
1110 /**
1111  * Send a line giving PHP memory usage.
1112  *
1113  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1114  */
1115 function wfDebugMem( $exact = false ) {
1116         $mem = memory_get_usage();
1117         if ( !$exact ) {
1118                 $mem = floor( $mem / 1024 ) . ' KiB';
1119         } else {
1120                 $mem .= ' B';
1121         }
1122         wfDebug( "Memory usage: $mem\n" );
1123 }
1124
1125 /**
1126  * Send a line to a supplementary debug log file, if configured, or main debug
1127  * log if not.
1128  *
1129  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1130  * a string filename or an associative array mapping 'destination' to the
1131  * desired filename. The associative array may also contain a 'sample' key
1132  * with an integer value, specifying a sampling factor. Sampled log events
1133  * will be emitted with a 1 in N random chance.
1134  *
1135  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1136  * @since 1.25 support for additional context data
1137  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1138  *
1139  * @param string $logGroup
1140  * @param string $text
1141  * @param string|bool $dest Destination of the message:
1142  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1143  *     - 'log': only to the log and not in HTML
1144  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1145  *       discarded otherwise
1146  *   For backward compatibility, it can also take a boolean:
1147  *     - true: same as 'all'
1148  *     - false: same as 'private'
1149  * @param array $context Additional logging context data
1150  */
1151 function wfDebugLog(
1152         $logGroup, $text, $dest = 'all', array $context = array()
1153 ) {
1154         // Turn $dest into a string if it's a boolean (for b/c)
1155         if ( $dest === true ) {
1156                 $dest = 'all';
1157         } elseif ( $dest === false ) {
1158                 $dest = 'private';
1159         }
1160
1161         $text = trim( $text );
1162
1163         $logger = LoggerFactory::getInstance( $logGroup );
1164         $context['private'] = ( $dest === 'private' );
1165         $logger->info( $text, $context );
1166 }
1167
1168 /**
1169  * Log for database errors
1170  *
1171  * @since 1.25 support for additional context data
1172  *
1173  * @param string $text Database error message.
1174  * @param array $context Additional logging context data
1175  */
1176 function wfLogDBError( $text, array $context = array() ) {
1177         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1178         $logger->error( trim( $text ), $context );
1179 }
1180
1181 /**
1182  * Throws a warning that $function is deprecated
1183  *
1184  * @param string $function
1185  * @param string|bool $version Version of MediaWiki that the function
1186  *    was deprecated in (Added in 1.19).
1187  * @param string|bool $component Added in 1.19.
1188  * @param int $callerOffset How far up the call stack is the original
1189  *    caller. 2 = function that called the function that called
1190  *    wfDeprecated (Added in 1.20)
1191  *
1192  * @return null
1193  */
1194 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1195         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1196 }
1197
1198 /**
1199  * Send a warning either to the debug log or in a PHP error depending on
1200  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1201  *
1202  * @param string $msg Message to send
1203  * @param int $callerOffset Number of items to go back in the backtrace to
1204  *        find the correct caller (1 = function calling wfWarn, ...)
1205  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1206  *        only used when $wgDevelopmentWarnings is true
1207  */
1208 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1209         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1210 }
1211
1212 /**
1213  * Send a warning as a PHP error and the debug log. This is intended for logging
1214  * warnings in production. For logging development warnings, use WfWarn instead.
1215  *
1216  * @param string $msg Message to send
1217  * @param int $callerOffset Number of items to go back in the backtrace to
1218  *        find the correct caller (1 = function calling wfLogWarning, ...)
1219  * @param int $level PHP error level; defaults to E_USER_WARNING
1220  */
1221 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1222         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1223 }
1224
1225 /**
1226  * Log to a file without getting "file size exceeded" signals.
1227  *
1228  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1229  * send lines to the specified port, prefixed by the specified prefix and a space.
1230  * @since 1.25 support for additional context data
1231  *
1232  * @param string $text
1233  * @param string $file Filename
1234  * @param array $context Additional logging context data
1235  * @throws MWException
1236  * @deprecated since 1.25 Use \\MediaWiki\\Logger\\LegacyLogger::emit or UDPTransport
1237  */
1238 function wfErrorLog( $text, $file, array $context = array() ) {
1239         wfDeprecated( __METHOD__, '1.25' );
1240         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1241         $context['destination'] = $file;
1242         $logger->info( trim( $text ), $context );
1243 }
1244
1245 /**
1246  * @todo document
1247  */
1248 function wfLogProfilingData() {
1249         global $wgDebugLogGroups, $wgDebugRawPage;
1250
1251         $context = RequestContext::getMain();
1252         $request = $context->getRequest();
1253
1254         $profiler = Profiler::instance();
1255         $profiler->setContext( $context );
1256         $profiler->logData();
1257
1258         $config = $context->getConfig();
1259         if ( $config->get( 'StatsdServer' ) ) {
1260                 try {
1261                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1262                         $statsdHost = $statsdServer[0];
1263                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1264                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1265                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1266                         $statsdClient->send( $context->getStats()->getBuffer() );
1267                 } catch ( Exception $ex ) {
1268                         MWExceptionHandler::logException( $ex );
1269                 }
1270         }
1271
1272         # Profiling must actually be enabled...
1273         if ( $profiler instanceof ProfilerStub ) {
1274                 return;
1275         }
1276
1277         if ( isset( $wgDebugLogGroups['profileoutput'] )
1278                 && $wgDebugLogGroups['profileoutput'] === false
1279         ) {
1280                 // Explicitly disabled
1281                 return;
1282         }
1283         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1284                 return;
1285         }
1286
1287         $ctx = array( 'elapsed' => $request->getElapsedTime() );
1288         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1289                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1290         }
1291         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1292                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1293         }
1294         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1295                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1296         }
1297         if ( isset( $ctx['forwarded_for'] ) ||
1298                 isset( $ctx['client_ip'] ) ||
1299                 isset( $ctx['from'] ) ) {
1300                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1301         }
1302
1303         // Don't load $wgUser at this late stage just for statistics purposes
1304         // @todo FIXME: We can detect some anons even if it is not loaded.
1305         // See User::getId()
1306         $user = $context->getUser();
1307         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1308
1309         // Command line script uses a FauxRequest object which does not have
1310         // any knowledge about an URL and throw an exception instead.
1311         try {
1312                 $ctx['url'] = urldecode( $request->getRequestURL() );
1313         } catch ( Exception $ignored ) {
1314                 // no-op
1315         }
1316
1317         $ctx['output'] = $profiler->getOutput();
1318
1319         $log = LoggerFactory::getInstance( 'profileoutput' );
1320         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1321 }
1322
1323 /**
1324  * Increment a statistics counter
1325  *
1326  * @param string $key
1327  * @param int $count
1328  * @return void
1329  */
1330 function wfIncrStats( $key, $count = 1 ) {
1331         $stats = RequestContext::getMain()->getStats();
1332         $stats->updateCount( $key, $count );
1333 }
1334
1335 /**
1336  * Check whether the wiki is in read-only mode.
1337  *
1338  * @return bool
1339  */
1340 function wfReadOnly() {
1341         return wfReadOnlyReason() !== false;
1342 }
1343
1344 /**
1345  * Check if the site is in read-only mode and return the message if so
1346  *
1347  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1348  * for slave lag. This may result in DB_SLAVE connection being made.
1349  *
1350  * @return string|bool String when in read-only mode; false otherwise
1351  */
1352 function wfReadOnlyReason() {
1353         $readOnly = wfConfiguredReadOnlyReason();
1354         if ( $readOnly !== false ) {
1355                 return $readOnly;
1356         }
1357
1358         static $lbReadOnly = null;
1359         if ( $lbReadOnly === null ) {
1360                 // Callers use this method to be aware that data presented to a user
1361                 // may be very stale and thus allowing submissions can be problematic.
1362                 $lbReadOnly = wfGetLB()->getReadOnlyReason();
1363         }
1364
1365         return $lbReadOnly;
1366 }
1367
1368 /**
1369  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1370  *
1371  * @return string|bool String when in read-only mode; false otherwise
1372  * @since 1.27
1373  */
1374 function wfConfiguredReadOnlyReason() {
1375         global $wgReadOnly, $wgReadOnlyFile;
1376
1377         if ( $wgReadOnly === null ) {
1378                 // Set $wgReadOnly for faster access next time
1379                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1380                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1381                 } else {
1382                         $wgReadOnly = false;
1383                 }
1384         }
1385
1386         return $wgReadOnly;
1387 }
1388
1389 /**
1390  * Return a Language object from $langcode
1391  *
1392  * @param Language|string|bool $langcode Either:
1393  *                  - a Language object
1394  *                  - code of the language to get the message for, if it is
1395  *                    a valid code create a language for that language, if
1396  *                    it is a string but not a valid code then make a basic
1397  *                    language object
1398  *                  - a boolean: if it's false then use the global object for
1399  *                    the current user's language (as a fallback for the old parameter
1400  *                    functionality), or if it is true then use global object
1401  *                    for the wiki's content language.
1402  * @return Language
1403  */
1404 function wfGetLangObj( $langcode = false ) {
1405         # Identify which language to get or create a language object for.
1406         # Using is_object here due to Stub objects.
1407         if ( is_object( $langcode ) ) {
1408                 # Great, we already have the object (hopefully)!
1409                 return $langcode;
1410         }
1411
1412         global $wgContLang, $wgLanguageCode;
1413         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1414                 # $langcode is the language code of the wikis content language object.
1415                 # or it is a boolean and value is true
1416                 return $wgContLang;
1417         }
1418
1419         global $wgLang;
1420         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1421                 # $langcode is the language code of user language object.
1422                 # or it was a boolean and value is false
1423                 return $wgLang;
1424         }
1425
1426         $validCodes = array_keys( Language::fetchLanguageNames() );
1427         if ( in_array( $langcode, $validCodes ) ) {
1428                 # $langcode corresponds to a valid language.
1429                 return Language::factory( $langcode );
1430         }
1431
1432         # $langcode is a string, but not a valid language code; use content language.
1433         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1434         return $wgContLang;
1435 }
1436
1437 /**
1438  * This is the function for getting translated interface messages.
1439  *
1440  * @see Message class for documentation how to use them.
1441  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1442  *
1443  * This function replaces all old wfMsg* functions.
1444  *
1445  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1446  * @param mixed $params,... Normal message parameters
1447  * @return Message
1448  *
1449  * @since 1.17
1450  *
1451  * @see Message::__construct
1452  */
1453 function wfMessage( $key /*...*/ ) {
1454         $params = func_get_args();
1455         array_shift( $params );
1456         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1457                 $params = $params[0];
1458         }
1459         return new Message( $key, $params );
1460 }
1461
1462 /**
1463  * This function accepts multiple message keys and returns a message instance
1464  * for the first message which is non-empty. If all messages are empty then an
1465  * instance of the first message key is returned.
1466  *
1467  * @param string|string[] $keys,... Message keys
1468  * @return Message
1469  *
1470  * @since 1.18
1471  *
1472  * @see Message::newFallbackSequence
1473  */
1474 function wfMessageFallback( /*...*/ ) {
1475         $args = func_get_args();
1476         return call_user_func_array( 'Message::newFallbackSequence', $args );
1477 }
1478
1479 /**
1480  * Get a message from anywhere, for the current user language.
1481  *
1482  * Use wfMsgForContent() instead if the message should NOT
1483  * change depending on the user preferences.
1484  *
1485  * @deprecated since 1.18
1486  *
1487  * @param string $key Lookup key for the message, usually
1488  *    defined in languages/Language.php
1489  *
1490  * Parameters to the message, which can be used to insert variable text into
1491  * it, can be passed to this function in the following formats:
1492  * - One per argument, starting at the second parameter
1493  * - As an array in the second parameter
1494  * These are not shown in the function definition.
1495  *
1496  * @return string
1497  */
1498 function wfMsg( $key ) {
1499         wfDeprecated( __METHOD__, '1.21' );
1500
1501         $args = func_get_args();
1502         array_shift( $args );
1503         return wfMsgReal( $key, $args );
1504 }
1505
1506 /**
1507  * Same as above except doesn't transform the message
1508  *
1509  * @deprecated since 1.18
1510  *
1511  * @param string $key
1512  * @return string
1513  */
1514 function wfMsgNoTrans( $key ) {
1515         wfDeprecated( __METHOD__, '1.21' );
1516
1517         $args = func_get_args();
1518         array_shift( $args );
1519         return wfMsgReal( $key, $args, true, false, false );
1520 }
1521
1522 /**
1523  * Get a message from anywhere, for the current global language
1524  * set with $wgLanguageCode.
1525  *
1526  * Use this if the message should NOT change dependent on the
1527  * language set in the user's preferences. This is the case for
1528  * most text written into logs, as well as link targets (such as
1529  * the name of the copyright policy page). Link titles, on the
1530  * other hand, should be shown in the UI language.
1531  *
1532  * Note that MediaWiki allows users to change the user interface
1533  * language in their preferences, but a single installation
1534  * typically only contains content in one language.
1535  *
1536  * Be wary of this distinction: If you use wfMsg() where you should
1537  * use wfMsgForContent(), a user of the software may have to
1538  * customize potentially hundreds of messages in
1539  * order to, e.g., fix a link in every possible language.
1540  *
1541  * @deprecated since 1.18
1542  *
1543  * @param string $key Lookup key for the message, usually
1544  *     defined in languages/Language.php
1545  * @return string
1546  */
1547 function wfMsgForContent( $key ) {
1548         wfDeprecated( __METHOD__, '1.21' );
1549
1550         global $wgForceUIMsgAsContentMsg;
1551         $args = func_get_args();
1552         array_shift( $args );
1553         $forcontent = true;
1554         if ( is_array( $wgForceUIMsgAsContentMsg )
1555                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1556         ) {
1557                 $forcontent = false;
1558         }
1559         return wfMsgReal( $key, $args, true, $forcontent );
1560 }
1561
1562 /**
1563  * Same as above except doesn't transform the message
1564  *
1565  * @deprecated since 1.18
1566  *
1567  * @param string $key
1568  * @return string
1569  */
1570 function wfMsgForContentNoTrans( $key ) {
1571         wfDeprecated( __METHOD__, '1.21' );
1572
1573         global $wgForceUIMsgAsContentMsg;
1574         $args = func_get_args();
1575         array_shift( $args );
1576         $forcontent = true;
1577         if ( is_array( $wgForceUIMsgAsContentMsg )
1578                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1579         ) {
1580                 $forcontent = false;
1581         }
1582         return wfMsgReal( $key, $args, true, $forcontent, false );
1583 }
1584
1585 /**
1586  * Really get a message
1587  *
1588  * @deprecated since 1.18
1589  *
1590  * @param string $key Key to get.
1591  * @param array $args
1592  * @param bool $useDB
1593  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1594  * @param bool $transform Whether or not to transform the message.
1595  * @return string The requested message.
1596  */
1597 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1598         wfDeprecated( __METHOD__, '1.21' );
1599
1600         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1601         $message = wfMsgReplaceArgs( $message, $args );
1602         return $message;
1603 }
1604
1605 /**
1606  * Fetch a message string value, but don't replace any keys yet.
1607  *
1608  * @deprecated since 1.18
1609  *
1610  * @param string $key
1611  * @param bool $useDB
1612  * @param string|bool $langCode Code of the language to get the message for, or
1613  *   behaves as a content language switch if it is a boolean.
1614  * @param bool $transform Whether to parse magic words, etc.
1615  * @return string
1616  */
1617 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1618         wfDeprecated( __METHOD__, '1.21' );
1619
1620         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1621
1622         $cache = MessageCache::singleton();
1623         $message = $cache->get( $key, $useDB, $langCode );
1624         if ( $message === false ) {
1625                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1626         } elseif ( $transform ) {
1627                 $message = $cache->transform( $message );
1628         }
1629         return $message;
1630 }
1631
1632 /**
1633  * Replace message parameter keys on the given formatted output.
1634  *
1635  * @param string $message
1636  * @param array $args
1637  * @return string
1638  * @private
1639  */
1640 function wfMsgReplaceArgs( $message, $args ) {
1641         # Fix windows line-endings
1642         # Some messages are split with explode("\n", $msg)
1643         $message = str_replace( "\r", '', $message );
1644
1645         // Replace arguments
1646         if ( count( $args ) ) {
1647                 if ( is_array( $args[0] ) ) {
1648                         $args = array_values( $args[0] );
1649                 }
1650                 $replacementKeys = array();
1651                 foreach ( $args as $n => $param ) {
1652                         $replacementKeys['$' . ( $n + 1 )] = $param;
1653                 }
1654                 $message = strtr( $message, $replacementKeys );
1655         }
1656
1657         return $message;
1658 }
1659
1660 /**
1661  * Return an HTML-escaped version of a message.
1662  * Parameter replacements, if any, are done *after* the HTML-escaping,
1663  * so parameters may contain HTML (eg links or form controls). Be sure
1664  * to pre-escape them if you really do want plaintext, or just wrap
1665  * the whole thing in htmlspecialchars().
1666  *
1667  * @deprecated since 1.18
1668  *
1669  * @param string $key
1670  * @param string $args,... Parameters
1671  * @return string
1672  */
1673 function wfMsgHtml( $key ) {
1674         wfDeprecated( __METHOD__, '1.21' );
1675
1676         $args = func_get_args();
1677         array_shift( $args );
1678         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1679 }
1680
1681 /**
1682  * Return an HTML version of message
1683  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1684  * so parameters may contain HTML (eg links or form controls). Be sure
1685  * to pre-escape them if you really do want plaintext, or just wrap
1686  * the whole thing in htmlspecialchars().
1687  *
1688  * @deprecated since 1.18
1689  *
1690  * @param string $key
1691  * @param string $args,... Parameters
1692  * @return string
1693  */
1694 function wfMsgWikiHtml( $key ) {
1695         wfDeprecated( __METHOD__, '1.21' );
1696
1697         $args = func_get_args();
1698         array_shift( $args );
1699         return wfMsgReplaceArgs(
1700                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1701                 /* can't be set to false */ true, /* interface */ true )->getText(),
1702                 $args );
1703 }
1704
1705 /**
1706  * Returns message in the requested format
1707  *
1708  * @deprecated since 1.18
1709  *
1710  * @param string $key Key of the message
1711  * @param array $options Processing rules.
1712  *   Can take the following options:
1713  *     parse: parses wikitext to HTML
1714  *     parseinline: parses wikitext to HTML and removes the surrounding
1715  *       p's added by parser or tidy
1716  *     escape: filters message through htmlspecialchars
1717  *     escapenoentities: same, but allows entity references like &#160; through
1718  *     replaceafter: parameters are substituted after parsing or escaping
1719  *     parsemag: transform the message using magic phrases
1720  *     content: fetch message for content language instead of interface
1721  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1722  *     language: Language object or language code to fetch message for
1723  *       (overridden by content).
1724  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1725  *
1726  * @return string
1727  */
1728 function wfMsgExt( $key, $options ) {
1729         wfDeprecated( __METHOD__, '1.21' );
1730
1731         $args = func_get_args();
1732         array_shift( $args );
1733         array_shift( $args );
1734         $options = (array)$options;
1735         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1736                 'parsemag', 'content' );
1737
1738         foreach ( $options as $arrayKey => $option ) {
1739                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1740                         // An unknown index, neither numeric nor "language"
1741                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1742                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1743                         // A numeric index with unknown value
1744                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1745                 }
1746         }
1747
1748         if ( in_array( 'content', $options, true ) ) {
1749                 $forContent = true;
1750                 $langCode = true;
1751                 $langCodeObj = null;
1752         } elseif ( array_key_exists( 'language', $options ) ) {
1753                 $forContent = false;
1754                 $langCode = wfGetLangObj( $options['language'] );
1755                 $langCodeObj = $langCode;
1756         } else {
1757                 $forContent = false;
1758                 $langCode = false;
1759                 $langCodeObj = null;
1760         }
1761
1762         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1763
1764         if ( !in_array( 'replaceafter', $options, true ) ) {
1765                 $string = wfMsgReplaceArgs( $string, $args );
1766         }
1767
1768         $messageCache = MessageCache::singleton();
1769         $parseInline = in_array( 'parseinline', $options, true );
1770         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1771                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1772                 if ( $string instanceof ParserOutput ) {
1773                         $string = $string->getText();
1774                 }
1775
1776                 if ( $parseInline ) {
1777                         $string = Parser::stripOuterParagraph( $string );
1778                 }
1779         } elseif ( in_array( 'parsemag', $options, true ) ) {
1780                 $string = $messageCache->transform( $string,
1781                                 !$forContent, $langCodeObj );
1782         }
1783
1784         if ( in_array( 'escape', $options, true ) ) {
1785                 $string = htmlspecialchars( $string );
1786         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1787                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1788         }
1789
1790         if ( in_array( 'replaceafter', $options, true ) ) {
1791                 $string = wfMsgReplaceArgs( $string, $args );
1792         }
1793
1794         return $string;
1795 }
1796
1797 /**
1798  * Since wfMsg() and co suck, they don't return false if the message key they
1799  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1800  * nonexistence of messages by checking the MessageCache::get() result directly.
1801  *
1802  * @deprecated since 1.18. Use Message::isDisabled().
1803  *
1804  * @param string $key The message key looked up
1805  * @return bool True if the message *doesn't* exist.
1806  */
1807 function wfEmptyMsg( $key ) {
1808         wfDeprecated( __METHOD__, '1.21' );
1809
1810         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1811 }
1812
1813 /**
1814  * Fetch server name for use in error reporting etc.
1815  * Use real server name if available, so we know which machine
1816  * in a server farm generated the current page.
1817  *
1818  * @return string
1819  */
1820 function wfHostname() {
1821         static $host;
1822         if ( is_null( $host ) ) {
1823
1824                 # Hostname overriding
1825                 global $wgOverrideHostname;
1826                 if ( $wgOverrideHostname !== false ) {
1827                         # Set static and skip any detection
1828                         $host = $wgOverrideHostname;
1829                         return $host;
1830                 }
1831
1832                 if ( function_exists( 'posix_uname' ) ) {
1833                         // This function not present on Windows
1834                         $uname = posix_uname();
1835                 } else {
1836                         $uname = false;
1837                 }
1838                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1839                         $host = $uname['nodename'];
1840                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1841                         # Windows computer name
1842                         $host = getenv( 'COMPUTERNAME' );
1843                 } else {
1844                         # This may be a virtual server.
1845                         $host = $_SERVER['SERVER_NAME'];
1846                 }
1847         }
1848         return $host;
1849 }
1850
1851 /**
1852  * Returns a script tag that stores the amount of time it took MediaWiki to
1853  * handle the request in milliseconds as 'wgBackendResponseTime'.
1854  *
1855  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1856  * hostname of the server handling the request.
1857  *
1858  * @return string
1859  */
1860 function wfReportTime() {
1861         global $wgRequestTime, $wgShowHostnames;
1862
1863         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1864         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1865         if ( $wgShowHostnames ) {
1866                 $reportVars['wgHostname'] = wfHostname();
1867         }
1868         return Skin::makeVariablesScript( $reportVars );
1869 }
1870
1871 /**
1872  * Safety wrapper for debug_backtrace().
1873  *
1874  * Will return an empty array if debug_backtrace is disabled, otherwise
1875  * the output from debug_backtrace() (trimmed).
1876  *
1877  * @param int $limit This parameter can be used to limit the number of stack frames returned
1878  *
1879  * @return array Array of backtrace information
1880  */
1881 function wfDebugBacktrace( $limit = 0 ) {
1882         static $disabled = null;
1883
1884         if ( is_null( $disabled ) ) {
1885                 $disabled = !function_exists( 'debug_backtrace' );
1886                 if ( $disabled ) {
1887                         wfDebug( "debug_backtrace() is disabled\n" );
1888                 }
1889         }
1890         if ( $disabled ) {
1891                 return array();
1892         }
1893
1894         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1895                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1896         } else {
1897                 return array_slice( debug_backtrace(), 1 );
1898         }
1899 }
1900
1901 /**
1902  * Get a debug backtrace as a string
1903  *
1904  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1905  *   Defaults to $wgCommandLineMode if unset.
1906  * @return string
1907  * @since 1.25 Supports $raw parameter.
1908  */
1909 function wfBacktrace( $raw = null ) {
1910         global $wgCommandLineMode;
1911
1912         if ( $raw === null ) {
1913                 $raw = $wgCommandLineMode;
1914         }
1915
1916         if ( $raw ) {
1917                 $frameFormat = "%s line %s calls %s()\n";
1918                 $traceFormat = "%s";
1919         } else {
1920                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1921                 $traceFormat = "<ul>\n%s</ul>\n";
1922         }
1923
1924         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1925                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1926                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1927                 $call = $frame['function'];
1928                 if ( !empty( $frame['class'] ) ) {
1929                         $call = $frame['class'] . $frame['type'] . $call;
1930                 }
1931                 return sprintf( $frameFormat, $file, $line, $call );
1932         }, wfDebugBacktrace() );
1933
1934         return sprintf( $traceFormat, implode( '', $frames ) );
1935 }
1936
1937 /**
1938  * Get the name of the function which called this function
1939  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1940  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1941  * wfGetCaller( 3 ) is the parent of that.
1942  *
1943  * @param int $level
1944  * @return string
1945  */
1946 function wfGetCaller( $level = 2 ) {
1947         $backtrace = wfDebugBacktrace( $level + 1 );
1948         if ( isset( $backtrace[$level] ) ) {
1949                 return wfFormatStackFrame( $backtrace[$level] );
1950         } else {
1951                 return 'unknown';
1952         }
1953 }
1954
1955 /**
1956  * Return a string consisting of callers in the stack. Useful sometimes
1957  * for profiling specific points.
1958  *
1959  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1960  * @return string
1961  */
1962 function wfGetAllCallers( $limit = 3 ) {
1963         $trace = array_reverse( wfDebugBacktrace() );
1964         if ( !$limit || $limit > count( $trace ) - 1 ) {
1965                 $limit = count( $trace ) - 1;
1966         }
1967         $trace = array_slice( $trace, -$limit - 1, $limit );
1968         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1969 }
1970
1971 /**
1972  * Return a string representation of frame
1973  *
1974  * @param array $frame
1975  * @return string
1976  */
1977 function wfFormatStackFrame( $frame ) {
1978         if ( !isset( $frame['function'] ) ) {
1979                 return 'NO_FUNCTION_GIVEN';
1980         }
1981         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1982                 $frame['class'] . $frame['type'] . $frame['function'] :
1983                 $frame['function'];
1984 }
1985
1986 /* Some generic result counters, pulled out of SearchEngine */
1987
1988 /**
1989  * @todo document
1990  *
1991  * @param int $offset
1992  * @param int $limit
1993  * @return string
1994  */
1995 function wfShowingResults( $offset, $limit ) {
1996         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1997 }
1998
1999 /**
2000  * @todo document
2001  * @todo FIXME: We may want to blacklist some broken browsers
2002  *
2003  * @param bool $force
2004  * @return bool Whereas client accept gzip compression
2005  */
2006 function wfClientAcceptsGzip( $force = false ) {
2007         static $result = null;
2008         if ( $result === null || $force ) {
2009                 $result = false;
2010                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2011                         # @todo FIXME: We may want to blacklist some broken browsers
2012                         $m = array();
2013                         if ( preg_match(
2014                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2015                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
2016                                         $m
2017                                 )
2018                         ) {
2019                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2020                                         $result = false;
2021                                         return $result;
2022                                 }
2023                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2024                                 $result = true;
2025                         }
2026                 }
2027         }
2028         return $result;
2029 }
2030
2031 /**
2032  * Obtain the offset and limit values from the request string;
2033  * used in special pages
2034  *
2035  * @param int $deflimit Default limit if none supplied
2036  * @param string $optionname Name of a user preference to check against
2037  * @return array
2038  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2039  */
2040 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2041         global $wgRequest;
2042         wfDeprecated( __METHOD__, '1.24' );
2043         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2044 }
2045
2046 /**
2047  * Escapes the given text so that it may be output using addWikiText()
2048  * without any linking, formatting, etc. making its way through. This
2049  * is achieved by substituting certain characters with HTML entities.
2050  * As required by the callers, "<nowiki>" is not used.
2051  *
2052  * @param string $text Text to be escaped
2053  * @return string
2054  */
2055 function wfEscapeWikiText( $text ) {
2056         static $repl = null, $repl2 = null;
2057         if ( $repl === null ) {
2058                 $repl = array(
2059                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2060                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2061                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2062                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2063                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2064                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2065                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2066                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2067                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2068                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2069                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2070                         '__' => '_&#95;', '://' => '&#58;//',
2071                 );
2072
2073                 // We have to catch everything "\s" matches in PCRE
2074                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2075                         $repl["$magic "] = "$magic&#32;";
2076                         $repl["$magic\t"] = "$magic&#9;";
2077                         $repl["$magic\r"] = "$magic&#13;";
2078                         $repl["$magic\n"] = "$magic&#10;";
2079                         $repl["$magic\f"] = "$magic&#12;";
2080                 }
2081
2082                 // And handle protocols that don't use "://"
2083                 global $wgUrlProtocols;
2084                 $repl2 = array();
2085                 foreach ( $wgUrlProtocols as $prot ) {
2086                         if ( substr( $prot, -1 ) === ':' ) {
2087                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2088                         }
2089                 }
2090                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2091         }
2092         $text = substr( strtr( "\n$text", $repl ), 1 );
2093         $text = preg_replace( $repl2, '$1&#58;', $text );
2094         return $text;
2095 }
2096
2097 /**
2098  * Sets dest to source and returns the original value of dest
2099  * If source is NULL, it just returns the value, it doesn't set the variable
2100  * If force is true, it will set the value even if source is NULL
2101  *
2102  * @param mixed $dest
2103  * @param mixed $source
2104  * @param bool $force
2105  * @return mixed
2106  */
2107 function wfSetVar( &$dest, $source, $force = false ) {
2108         $temp = $dest;
2109         if ( !is_null( $source ) || $force ) {
2110                 $dest = $source;
2111         }
2112         return $temp;
2113 }
2114
2115 /**
2116  * As for wfSetVar except setting a bit
2117  *
2118  * @param int $dest
2119  * @param int $bit
2120  * @param bool $state
2121  *
2122  * @return bool
2123  */
2124 function wfSetBit( &$dest, $bit, $state = true ) {
2125         $temp = (bool)( $dest & $bit );
2126         if ( !is_null( $state ) ) {
2127                 if ( $state ) {
2128                         $dest |= $bit;
2129                 } else {
2130                         $dest &= ~$bit;
2131                 }
2132         }
2133         return $temp;
2134 }
2135
2136 /**
2137  * A wrapper around the PHP function var_export().
2138  * Either print it or add it to the regular output ($wgOut).
2139  *
2140  * @param mixed $var A PHP variable to dump.
2141  */
2142 function wfVarDump( $var ) {
2143         global $wgOut;
2144         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2145         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2146                 print $s;
2147         } else {
2148                 $wgOut->addHTML( $s );
2149         }
2150 }
2151
2152 /**
2153  * Provide a simple HTTP error.
2154  *
2155  * @param int|string $code
2156  * @param string $label
2157  * @param string $desc
2158  */
2159 function wfHttpError( $code, $label, $desc ) {
2160         global $wgOut;
2161         HttpStatus::header( $code );
2162         if ( $wgOut ) {
2163                 $wgOut->disable();
2164                 $wgOut->sendCacheControl();
2165         }
2166
2167         header( 'Content-type: text/html; charset=utf-8' );
2168         print '<!DOCTYPE html>' .
2169                 '<html><head><title>' .
2170                 htmlspecialchars( $label ) .
2171                 '</title></head><body><h1>' .
2172                 htmlspecialchars( $label ) .
2173                 '</h1><p>' .
2174                 nl2br( htmlspecialchars( $desc ) ) .
2175                 "</p></body></html>\n";
2176 }
2177
2178 /**
2179  * Clear away any user-level output buffers, discarding contents.
2180  *
2181  * Suitable for 'starting afresh', for instance when streaming
2182  * relatively large amounts of data without buffering, or wanting to
2183  * output image files without ob_gzhandler's compression.
2184  *
2185  * The optional $resetGzipEncoding parameter controls suppression of
2186  * the Content-Encoding header sent by ob_gzhandler; by default it
2187  * is left. See comments for wfClearOutputBuffers() for why it would
2188  * be used.
2189  *
2190  * Note that some PHP configuration options may add output buffer
2191  * layers which cannot be removed; these are left in place.
2192  *
2193  * @param bool $resetGzipEncoding
2194  */
2195 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2196         if ( $resetGzipEncoding ) {
2197                 // Suppress Content-Encoding and Content-Length
2198                 // headers from 1.10+s wfOutputHandler
2199                 global $wgDisableOutputCompression;
2200                 $wgDisableOutputCompression = true;
2201         }
2202         while ( $status = ob_get_status() ) {
2203                 if ( isset( $status['flags'] ) ) {
2204                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
2205                         $deleteable = ( $status['flags'] & $flags ) === $flags;
2206                 } elseif ( isset( $status['del'] ) ) {
2207                         $deleteable = $status['del'];
2208                 } else {
2209                         // Guess that any PHP-internal setting can't be removed.
2210                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
2211                 }
2212                 if ( !$deleteable ) {
2213                         // Give up, and hope the result doesn't break
2214                         // output behavior.
2215                         break;
2216                 }
2217                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
2218                         // Unit testing barrier to prevent this function from breaking PHPUnit.
2219                         break;
2220                 }
2221                 if ( !ob_end_clean() ) {
2222                         // Could not remove output buffer handler; abort now
2223                         // to avoid getting in some kind of infinite loop.
2224                         break;
2225                 }
2226                 if ( $resetGzipEncoding ) {
2227                         if ( $status['name'] == 'ob_gzhandler' ) {
2228                                 // Reset the 'Content-Encoding' field set by this handler
2229                                 // so we can start fresh.
2230                                 header_remove( 'Content-Encoding' );
2231                                 break;
2232                         }
2233                 }
2234         }
2235 }
2236
2237 /**
2238  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2239  *
2240  * Clear away output buffers, but keep the Content-Encoding header
2241  * produced by ob_gzhandler, if any.
2242  *
2243  * This should be used for HTTP 304 responses, where you need to
2244  * preserve the Content-Encoding header of the real result, but
2245  * also need to suppress the output of ob_gzhandler to keep to spec
2246  * and avoid breaking Firefox in rare cases where the headers and
2247  * body are broken over two packets.
2248  */
2249 function wfClearOutputBuffers() {
2250         wfResetOutputBuffers( false );
2251 }
2252
2253 /**
2254  * Converts an Accept-* header into an array mapping string values to quality
2255  * factors
2256  *
2257  * @param string $accept
2258  * @param string $def Default
2259  * @return float[] Associative array of string => float pairs
2260  */
2261 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2262         # No arg means accept anything (per HTTP spec)
2263         if ( !$accept ) {
2264                 return array( $def => 1.0 );
2265         }
2266
2267         $prefs = array();
2268
2269         $parts = explode( ',', $accept );
2270
2271         foreach ( $parts as $part ) {
2272                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2273                 $values = explode( ';', trim( $part ) );
2274                 $match = array();
2275                 if ( count( $values ) == 1 ) {
2276                         $prefs[$values[0]] = 1.0;
2277                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2278                         $prefs[$values[0]] = floatval( $match[1] );
2279                 }
2280         }
2281
2282         return $prefs;
2283 }
2284
2285 /**
2286  * Checks if a given MIME type matches any of the keys in the given
2287  * array. Basic wildcards are accepted in the array keys.
2288  *
2289  * Returns the matching MIME type (or wildcard) if a match, otherwise
2290  * NULL if no match.
2291  *
2292  * @param string $type
2293  * @param array $avail
2294  * @return string
2295  * @private
2296  */
2297 function mimeTypeMatch( $type, $avail ) {
2298         if ( array_key_exists( $type, $avail ) ) {
2299                 return $type;
2300         } else {
2301                 $parts = explode( '/', $type );
2302                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2303                         return $parts[0] . '/*';
2304                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2305                         return '*/*';
2306                 } else {
2307                         return null;
2308                 }
2309         }
2310 }
2311
2312 /**
2313  * Returns the 'best' match between a client's requested internet media types
2314  * and the server's list of available types. Each list should be an associative
2315  * array of type to preference (preference is a float between 0.0 and 1.0).
2316  * Wildcards in the types are acceptable.
2317  *
2318  * @param array $cprefs Client's acceptable type list
2319  * @param array $sprefs Server's offered types
2320  * @return string
2321  *
2322  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2323  * XXX: generalize to negotiate other stuff
2324  */
2325 function wfNegotiateType( $cprefs, $sprefs ) {
2326         $combine = array();
2327
2328         foreach ( array_keys( $sprefs ) as $type ) {
2329                 $parts = explode( '/', $type );
2330                 if ( $parts[1] != '*' ) {
2331                         $ckey = mimeTypeMatch( $type, $cprefs );
2332                         if ( $ckey ) {
2333                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2334                         }
2335                 }
2336         }
2337
2338         foreach ( array_keys( $cprefs ) as $type ) {
2339                 $parts = explode( '/', $type );
2340                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2341                         $skey = mimeTypeMatch( $type, $sprefs );
2342                         if ( $skey ) {
2343                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2344                         }
2345                 }
2346         }
2347
2348         $bestq = 0;
2349         $besttype = null;
2350
2351         foreach ( array_keys( $combine ) as $type ) {
2352                 if ( $combine[$type] > $bestq ) {
2353                         $besttype = $type;
2354                         $bestq = $combine[$type];
2355                 }
2356         }
2357
2358         return $besttype;
2359 }
2360
2361 /**
2362  * Reference-counted warning suppression
2363  *
2364  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
2365  * @param bool $end
2366  */
2367 function wfSuppressWarnings( $end = false ) {
2368         MediaWiki\suppressWarnings( $end );
2369 }
2370
2371 /**
2372  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
2373  * Restore error level to previous value
2374  */
2375 function wfRestoreWarnings() {
2376         MediaWiki\suppressWarnings( true );
2377 }
2378
2379 # Autodetect, convert and provide timestamps of various types
2380
2381 /**
2382  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2383  */
2384 define( 'TS_UNIX', 0 );
2385
2386 /**
2387  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2388  */
2389 define( 'TS_MW', 1 );
2390
2391 /**
2392  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2393  */
2394 define( 'TS_DB', 2 );
2395
2396 /**
2397  * RFC 2822 format, for E-mail and HTTP headers
2398  */
2399 define( 'TS_RFC2822', 3 );
2400
2401 /**
2402  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2403  *
2404  * This is used by Special:Export
2405  */
2406 define( 'TS_ISO_8601', 4 );
2407
2408 /**
2409  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2410  *
2411  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2412  *       DateTime tag and page 36 for the DateTimeOriginal and
2413  *       DateTimeDigitized tags.
2414  */
2415 define( 'TS_EXIF', 5 );
2416
2417 /**
2418  * Oracle format time.
2419  */
2420 define( 'TS_ORACLE', 6 );
2421
2422 /**
2423  * Postgres format time.
2424  */
2425 define( 'TS_POSTGRES', 7 );
2426
2427 /**
2428  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2429  */
2430 define( 'TS_ISO_8601_BASIC', 9 );
2431
2432 /**
2433  * Get a timestamp string in one of various formats
2434  *
2435  * @param mixed $outputtype A timestamp in one of the supported formats, the
2436  *   function will autodetect which format is supplied and act accordingly.
2437  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2438  * @return string|bool String / false The same date in the format specified in $outputtype or false
2439  */
2440 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2441         try {
2442                 $timestamp = new MWTimestamp( $ts );
2443                 return $timestamp->getTimestamp( $outputtype );
2444         } catch ( TimestampException $e ) {
2445                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2446                 return false;
2447         }
2448 }
2449
2450 /**
2451  * Return a formatted timestamp, or null if input is null.
2452  * For dealing with nullable timestamp columns in the database.
2453  *
2454  * @param int $outputtype
2455  * @param string $ts
2456  * @return string
2457  */
2458 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2459         if ( is_null( $ts ) ) {
2460                 return null;
2461         } else {
2462                 return wfTimestamp( $outputtype, $ts );
2463         }
2464 }
2465
2466 /**
2467  * Convenience function; returns MediaWiki timestamp for the present time.
2468  *
2469  * @return string
2470  */
2471 function wfTimestampNow() {
2472         # return NOW
2473         return wfTimestamp( TS_MW, time() );
2474 }
2475
2476 /**
2477  * Check if the operating system is Windows
2478  *
2479  * @return bool True if it's Windows, false otherwise.
2480  */
2481 function wfIsWindows() {
2482         static $isWindows = null;
2483         if ( $isWindows === null ) {
2484                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2485         }
2486         return $isWindows;
2487 }
2488
2489 /**
2490  * Check if we are running under HHVM
2491  *
2492  * @return bool
2493  */
2494 function wfIsHHVM() {
2495         return defined( 'HHVM_VERSION' );
2496 }
2497
2498 /**
2499  * Tries to get the system directory for temporary files. First
2500  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2501  * environment variables are then checked in sequence, and if none are
2502  * set try sys_get_temp_dir().
2503  *
2504  * NOTE: When possible, use instead the tmpfile() function to create
2505  * temporary files to avoid race conditions on file creation, etc.
2506  *
2507  * @return string
2508  */
2509 function wfTempDir() {
2510         global $wgTmpDirectory;
2511
2512         if ( $wgTmpDirectory !== false ) {
2513                 return $wgTmpDirectory;
2514         }
2515
2516         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2517
2518         foreach ( $tmpDir as $tmp ) {
2519                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2520                         return $tmp;
2521                 }
2522         }
2523         return sys_get_temp_dir();
2524 }
2525
2526 /**
2527  * Make directory, and make all parent directories if they don't exist
2528  *
2529  * @param string $dir Full path to directory to create
2530  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2531  * @param string $caller Optional caller param for debugging.
2532  * @throws MWException
2533  * @return bool
2534  */
2535 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2536         global $wgDirectoryMode;
2537
2538         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2539                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2540         }
2541
2542         if ( !is_null( $caller ) ) {
2543                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2544         }
2545
2546         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2547                 return true;
2548         }
2549
2550         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2551
2552         if ( is_null( $mode ) ) {
2553                 $mode = $wgDirectoryMode;
2554         }
2555
2556         // Turn off the normal warning, we're doing our own below
2557         MediaWiki\suppressWarnings();
2558         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2559         MediaWiki\restoreWarnings();
2560
2561         if ( !$ok ) {
2562                 // directory may have been created on another request since we last checked
2563                 if ( is_dir( $dir ) ) {
2564                         return true;
2565                 }
2566
2567                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2568                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2569         }
2570         return $ok;
2571 }
2572
2573 /**
2574  * Remove a directory and all its content.
2575  * Does not hide error.
2576  * @param string $dir
2577  */
2578 function wfRecursiveRemoveDir( $dir ) {
2579         wfDebug( __FUNCTION__ . "( $dir )\n" );
2580         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2581         if ( is_dir( $dir ) ) {
2582                 $objects = scandir( $dir );
2583                 foreach ( $objects as $object ) {
2584                         if ( $object != "." && $object != ".." ) {
2585                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2586                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2587                                 } else {
2588                                         unlink( $dir . '/' . $object );
2589                                 }
2590                         }
2591                 }
2592                 reset( $objects );
2593                 rmdir( $dir );
2594         }
2595 }
2596
2597 /**
2598  * @param int $nr The number to format
2599  * @param int $acc The number of digits after the decimal point, default 2
2600  * @param bool $round Whether or not to round the value, default true
2601  * @return string
2602  */
2603 function wfPercent( $nr, $acc = 2, $round = true ) {
2604         $ret = sprintf( "%.${acc}f", $nr );
2605         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2606 }
2607
2608 /**
2609  * Safety wrapper around ini_get() for boolean settings.
2610  * The values returned from ini_get() are pre-normalized for settings
2611  * set via php.ini or php_flag/php_admin_flag... but *not*
2612  * for those set via php_value/php_admin_value.
2613  *
2614  * It's fairly common for people to use php_value instead of php_flag,
2615  * which can leave you with an 'off' setting giving a false positive
2616  * for code that just takes the ini_get() return value as a boolean.
2617  *
2618  * To make things extra interesting, setting via php_value accepts
2619  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2620  * Unrecognized values go false... again opposite PHP's own coercion
2621  * from string to bool.
2622  *
2623  * Luckily, 'properly' set settings will always come back as '0' or '1',
2624  * so we only have to worry about them and the 'improper' settings.
2625  *
2626  * I frickin' hate PHP... :P
2627  *
2628  * @param string $setting
2629  * @return bool
2630  */
2631 function wfIniGetBool( $setting ) {
2632         $val = strtolower( ini_get( $setting ) );
2633         // 'on' and 'true' can't have whitespace around them, but '1' can.
2634         return $val == 'on'
2635                 || $val == 'true'
2636                 || $val == 'yes'
2637                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2638 }
2639
2640 /**
2641  * Windows-compatible version of escapeshellarg()
2642  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2643  * function puts single quotes in regardless of OS.
2644  *
2645  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2646  * earlier distro releases of PHP)
2647  *
2648  * @param string ... strings to escape and glue together, or a single array of strings parameter
2649  * @return string
2650  */
2651 function wfEscapeShellArg( /*...*/ ) {
2652         wfInitShellLocale();
2653
2654         $args = func_get_args();
2655         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2656                 // If only one argument has been passed, and that argument is an array,
2657                 // treat it as a list of arguments
2658                 $args = reset( $args );
2659         }
2660
2661         $first = true;
2662         $retVal = '';
2663         foreach ( $args as $arg ) {
2664                 if ( !$first ) {
2665                         $retVal .= ' ';
2666                 } else {
2667                         $first = false;
2668                 }
2669
2670                 if ( wfIsWindows() ) {
2671                         // Escaping for an MSVC-style command line parser and CMD.EXE
2672                         // @codingStandardsIgnoreStart For long URLs
2673                         // Refs:
2674                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2675                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2676                         //  * Bug #13518
2677                         //  * CR r63214
2678                         // Double the backslashes before any double quotes. Escape the double quotes.
2679                         // @codingStandardsIgnoreEnd
2680                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2681                         $arg = '';
2682                         $iteration = 0;
2683                         foreach ( $tokens as $token ) {
2684                                 if ( $iteration % 2 == 1 ) {
2685                                         // Delimiter, a double quote preceded by zero or more slashes
2686                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2687                                 } elseif ( $iteration % 4 == 2 ) {
2688                                         // ^ in $token will be outside quotes, need to be escaped
2689                                         $arg .= str_replace( '^', '^^', $token );
2690                                 } else { // $iteration % 4 == 0
2691                                         // ^ in $token will appear inside double quotes, so leave as is
2692                                         $arg .= $token;
2693                                 }
2694                                 $iteration++;
2695                         }
2696                         // Double the backslashes before the end of the string, because
2697                         // we will soon add a quote
2698                         $m = array();
2699                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2700                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2701                         }
2702
2703                         // Add surrounding quotes
2704                         $retVal .= '"' . $arg . '"';
2705                 } else {
2706                         $retVal .= escapeshellarg( $arg );
2707                 }
2708         }
2709         return $retVal;
2710 }
2711
2712 /**
2713  * Check if wfShellExec() is effectively disabled via php.ini config
2714  *
2715  * @return bool|string False or one of (safemode,disabled)
2716  * @since 1.22
2717  */
2718 function wfShellExecDisabled() {
2719         static $disabled = null;
2720         if ( is_null( $disabled ) ) {
2721                 if ( wfIniGetBool( 'safe_mode' ) ) {
2722                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2723                         $disabled = 'safemode';
2724                 } elseif ( !function_exists( 'proc_open' ) ) {
2725                         wfDebug( "proc_open() is disabled\n" );
2726                         $disabled = 'disabled';
2727                 } else {
2728                         $disabled = false;
2729                 }
2730         }
2731         return $disabled;
2732 }
2733
2734 /**
2735  * Execute a shell command, with time and memory limits mirrored from the PHP
2736  * configuration if supported.
2737  *
2738  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2739  *   or an array of unescaped arguments, in which case each value will be escaped
2740  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2741  * @param null|mixed &$retval Optional, will receive the program's exit code.
2742  *   (non-zero is usually failure). If there is an error from
2743  *   read, select, or proc_open(), this will be set to -1.
2744  * @param array $environ Optional environment variables which should be
2745  *   added to the executed command environment.
2746  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2747  *   this overwrites the global wgMaxShell* limits.
2748  * @param array $options Array of options:
2749  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2750  *     including errors from limit.sh
2751  *   - profileMethod: By default this function will profile based on the calling
2752  *     method. Set this to a string for an alternative method to profile from
2753  *
2754  * @return string Collected stdout as a string
2755  */
2756 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2757         $limits = array(), $options = array()
2758 ) {
2759         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2760                 $wgMaxShellWallClockTime, $wgShellCgroup;
2761
2762         $disabled = wfShellExecDisabled();
2763         if ( $disabled ) {
2764                 $retval = 1;
2765                 return $disabled == 'safemode' ?
2766                         'Unable to run external programs in safe mode.' :
2767                         'Unable to run external programs, proc_open() is disabled.';
2768         }
2769
2770         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2771         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2772
2773         wfInitShellLocale();
2774
2775         $envcmd = '';
2776         foreach ( $environ as $k => $v ) {
2777                 if ( wfIsWindows() ) {
2778                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2779                          * appear in the environment variable, so we must use carat escaping as documented in
2780                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2781                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2782                          * are listed there but doesn't appear to need it.
2783                          */
2784                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2785                 } else {
2786                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2787                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2788                          */
2789                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2790                 }
2791         }
2792         if ( is_array( $cmd ) ) {
2793                 $cmd = wfEscapeShellArg( $cmd );
2794         }
2795
2796         $cmd = $envcmd . $cmd;
2797
2798         $useLogPipe = false;
2799         if ( is_executable( '/bin/bash' ) ) {
2800                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2801                 if ( isset( $limits['walltime'] ) ) {
2802                         $wallTime = intval( $limits['walltime'] );
2803                 } elseif ( isset( $limits['time'] ) ) {
2804                         $wallTime = $time;
2805                 } else {
2806                         $wallTime = intval( $wgMaxShellWallClockTime );
2807                 }
2808                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2809                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2810
2811                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2812                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2813                                 escapeshellarg( $cmd ) . ' ' .
2814                                 escapeshellarg(
2815                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2816                                         "MW_CPU_LIMIT=$time; " .
2817                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2818                                         "MW_MEM_LIMIT=$mem; " .
2819                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2820                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2821                                         "MW_USE_LOG_PIPE=yes"
2822                                 );
2823                         $useLogPipe = true;
2824                 } elseif ( $includeStderr ) {
2825                         $cmd .= ' 2>&1';
2826                 }
2827         } elseif ( $includeStderr ) {
2828                 $cmd .= ' 2>&1';
2829         }
2830         wfDebug( "wfShellExec: $cmd\n" );
2831
2832         $desc = array(
2833                 0 => array( 'file', 'php://stdin', 'r' ),
2834                 1 => array( 'pipe', 'w' ),
2835                 2 => array( 'file', 'php://stderr', 'w' ) );
2836         if ( $useLogPipe ) {
2837                 $desc[3] = array( 'pipe', 'w' );
2838         }
2839         $pipes = null;
2840         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2841         $proc = proc_open( $cmd, $desc, $pipes );
2842         if ( !$proc ) {
2843                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2844                 $retval = -1;
2845                 return '';
2846         }
2847         $outBuffer = $logBuffer = '';
2848         $emptyArray = array();
2849         $status = false;
2850         $logMsg = false;
2851
2852         /* According to the documentation, it is possible for stream_select()
2853          * to fail due to EINTR. I haven't managed to induce this in testing
2854          * despite sending various signals. If it did happen, the error
2855          * message would take the form:
2856          *
2857          * stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2858          *
2859          * where [4] is the value of the macro EINTR and "Interrupted system
2860          * call" is string which according to the Linux manual is "possibly"
2861          * localised according to LC_MESSAGES.
2862          */
2863         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2864         $eintrMessage = "stream_select(): unable to select [$eintr]";
2865
2866         // Build a table mapping resource IDs to pipe FDs to work around a
2867         // PHP 5.3 issue in which stream_select() does not preserve array keys
2868         // <https://bugs.php.net/bug.php?id=53427>.
2869         $fds = array();
2870         foreach ( $pipes as $fd => $pipe ) {
2871                 $fds[(int)$pipe] = $fd;
2872         }
2873
2874         $running = true;
2875         $timeout = null;
2876         $numReadyPipes = 0;
2877
2878         while ( $running === true || $numReadyPipes !== 0 ) {
2879                 if ( $running ) {
2880                         $status = proc_get_status( $proc );
2881                         // If the process has terminated, switch to nonblocking selects
2882                         // for getting any data still waiting to be read.
2883                         if ( !$status['running'] ) {
2884                                 $running = false;
2885                                 $timeout = 0;
2886                         }
2887                 }
2888
2889                 $readyPipes = $pipes;
2890
2891                 // Clear last error
2892                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2893                 @trigger_error( '' );
2894                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2895                 if ( $numReadyPipes === false ) {
2896                         // @codingStandardsIgnoreEnd
2897                         $error = error_get_last();
2898                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2899                                 continue;
2900                         } else {
2901                                 trigger_error( $error['message'], E_USER_WARNING );
2902                                 $logMsg = $error['message'];
2903                                 break;
2904                         }
2905                 }
2906                 foreach ( $readyPipes as $pipe ) {
2907                         $block = fread( $pipe, 65536 );
2908                         $fd = $fds[(int)$pipe];
2909                         if ( $block === '' ) {
2910                                 // End of file
2911                                 fclose( $pipes[$fd] );
2912                                 unset( $pipes[$fd] );
2913                                 if ( !$pipes ) {
2914                                         break 2;
2915                                 }
2916                         } elseif ( $block === false ) {
2917                                 // Read error
2918                                 $logMsg = "Error reading from pipe";
2919                                 break 2;
2920                         } elseif ( $fd == 1 ) {
2921                                 // From stdout
2922                                 $outBuffer .= $block;
2923                         } elseif ( $fd == 3 ) {
2924                                 // From log FD
2925                                 $logBuffer .= $block;
2926                                 if ( strpos( $block, "\n" ) !== false ) {
2927                                         $lines = explode( "\n", $logBuffer );
2928                                         $logBuffer = array_pop( $lines );
2929                                         foreach ( $lines as $line ) {
2930                                                 wfDebugLog( 'exec', $line );
2931                                         }
2932                                 }
2933                         }
2934                 }
2935         }
2936
2937         foreach ( $pipes as $pipe ) {
2938                 fclose( $pipe );
2939         }
2940
2941         // Use the status previously collected if possible, since proc_get_status()
2942         // just calls waitpid() which will not return anything useful the second time.
2943         if ( $running ) {
2944                 $status = proc_get_status( $proc );
2945         }
2946
2947         if ( $logMsg !== false ) {
2948                 // Read/select error
2949                 $retval = -1;
2950                 proc_close( $proc );
2951         } elseif ( $status['signaled'] ) {
2952                 $logMsg = "Exited with signal {$status['termsig']}";
2953                 $retval = 128 + $status['termsig'];
2954                 proc_close( $proc );
2955         } else {
2956                 if ( $status['running'] ) {
2957                         $retval = proc_close( $proc );
2958                 } else {
2959                         $retval = $status['exitcode'];
2960                         proc_close( $proc );
2961                 }
2962                 if ( $retval == 127 ) {
2963                         $logMsg = "Possibly missing executable file";
2964                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2965                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2966                 }
2967         }
2968
2969         if ( $logMsg !== false ) {
2970                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2971         }
2972
2973         return $outBuffer;
2974 }
2975
2976 /**
2977  * Execute a shell command, returning both stdout and stderr. Convenience
2978  * function, as all the arguments to wfShellExec can become unwieldy.
2979  *
2980  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2981  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2982  *   or an array of unescaped arguments, in which case each value will be escaped
2983  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2984  * @param null|mixed &$retval Optional, will receive the program's exit code.
2985  *   (non-zero is usually failure)
2986  * @param array $environ Optional environment variables which should be
2987  *   added to the executed command environment.
2988  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2989  *   this overwrites the global wgMaxShell* limits.
2990  * @return string Collected stdout and stderr as a string
2991  */
2992 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2993         return wfShellExec( $cmd, $retval, $environ, $limits,
2994                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2995 }
2996
2997 /**
2998  * Workaround for http://bugs.php.net/bug.php?id=45132
2999  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
3000  */
3001 function wfInitShellLocale() {
3002         static $done = false;
3003         if ( $done ) {
3004                 return;
3005         }
3006         $done = true;
3007         global $wgShellLocale;
3008         if ( !wfIniGetBool( 'safe_mode' ) ) {
3009                 putenv( "LC_CTYPE=$wgShellLocale" );
3010                 setlocale( LC_CTYPE, $wgShellLocale );
3011         }
3012 }
3013
3014 /**
3015  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3016  * Note that $parameters should be a flat array and an option with an argument
3017  * should consist of two consecutive items in the array (do not use "--option value").
3018  *
3019  * @param string $script MediaWiki cli script path
3020  * @param array $parameters Arguments and options to the script
3021  * @param array $options Associative array of options:
3022  *              'php': The path to the php executable
3023  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3024  * @return string
3025  */
3026 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3027         global $wgPhpCli;
3028         // Give site config file a chance to run the script in a wrapper.
3029         // The caller may likely want to call wfBasename() on $script.
3030         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3031         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3032         if ( isset( $options['wrapper'] ) ) {
3033                 $cmd[] = $options['wrapper'];
3034         }
3035         $cmd[] = $script;
3036         // Escape each parameter for shell
3037         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3038 }
3039
3040 /**
3041  * wfMerge attempts to merge differences between three texts.
3042  * Returns true for a clean merge and false for failure or a conflict.
3043  *
3044  * @param string $old
3045  * @param string $mine
3046  * @param string $yours
3047  * @param string $result
3048  * @return bool
3049  */
3050 function wfMerge( $old, $mine, $yours, &$result ) {
3051         global $wgDiff3;
3052
3053         # This check may also protect against code injection in
3054         # case of broken installations.
3055         MediaWiki\suppressWarnings();
3056         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3057         MediaWiki\restoreWarnings();
3058
3059         if ( !$haveDiff3 ) {
3060                 wfDebug( "diff3 not found\n" );
3061                 return false;
3062         }
3063
3064         # Make temporary files
3065         $td = wfTempDir();
3066         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3067         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3068         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3069
3070         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3071         #       a newline character. To avoid this, we normalize the trailing whitespace before
3072         #       creating the diff.
3073
3074         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3075         fclose( $oldtextFile );
3076         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3077         fclose( $mytextFile );
3078         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3079         fclose( $yourtextFile );
3080
3081         # Check for a conflict
3082         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
3083                 $oldtextName, $yourtextName );
3084         $handle = popen( $cmd, 'r' );
3085
3086         if ( fgets( $handle, 1024 ) ) {
3087                 $conflict = true;
3088         } else {
3089                 $conflict = false;
3090         }
3091         pclose( $handle );
3092
3093         # Merge differences
3094         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
3095                 $oldtextName, $yourtextName );
3096         $handle = popen( $cmd, 'r' );
3097         $result = '';
3098         do {
3099                 $data = fread( $handle, 8192 );
3100                 if ( strlen( $data ) == 0 ) {
3101                         break;
3102                 }
3103                 $result .= $data;
3104         } while ( true );
3105         pclose( $handle );
3106         unlink( $mytextName );
3107         unlink( $oldtextName );
3108         unlink( $yourtextName );
3109
3110         if ( $result === '' && $old !== '' && !$conflict ) {
3111                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3112                 $conflict = true;
3113         }
3114         return !$conflict;
3115 }
3116
3117 /**
3118  * Returns unified plain-text diff of two texts.
3119  * "Useful" for machine processing of diffs.
3120  *
3121  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3122  *
3123  * @param string $before The text before the changes.
3124  * @param string $after The text after the changes.
3125  * @param string $params Command-line options for the diff command.
3126  * @return string Unified diff of $before and $after
3127  */
3128 function wfDiff( $before, $after, $params = '-u' ) {
3129         if ( $before == $after ) {
3130                 return '';
3131         }
3132
3133         global $wgDiff;
3134         MediaWiki\suppressWarnings();
3135         $haveDiff = $wgDiff && file_exists( $wgDiff );
3136         MediaWiki\restoreWarnings();
3137
3138         # This check may also protect against code injection in
3139         # case of broken installations.
3140         if ( !$haveDiff ) {
3141                 wfDebug( "diff executable not found\n" );
3142                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3143                 $format = new UnifiedDiffFormatter();
3144                 return $format->format( $diffs );
3145         }
3146
3147         # Make temporary files
3148         $td = wfTempDir();
3149         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3150         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3151
3152         fwrite( $oldtextFile, $before );
3153         fclose( $oldtextFile );
3154         fwrite( $newtextFile, $after );
3155         fclose( $newtextFile );
3156
3157         // Get the diff of the two files
3158         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3159
3160         $h = popen( $cmd, 'r' );
3161         if ( !$h ) {
3162                 unlink( $oldtextName );
3163                 unlink( $newtextName );
3164                 throw new Exception( __METHOD__ . '(): popen() failed' );
3165         }
3166
3167         $diff = '';
3168
3169         do {
3170                 $data = fread( $h, 8192 );
3171                 if ( strlen( $data ) == 0 ) {
3172                         break;
3173                 }
3174                 $diff .= $data;
3175         } while ( true );
3176
3177         // Clean up
3178         pclose( $h );
3179         unlink( $oldtextName );
3180         unlink( $newtextName );
3181
3182         // Kill the --- and +++ lines. They're not useful.
3183         $diff_lines = explode( "\n", $diff );
3184         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3185                 unset( $diff_lines[0] );
3186         }
3187         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3188                 unset( $diff_lines[1] );
3189         }
3190
3191         $diff = implode( "\n", $diff_lines );
3192
3193         return $diff;
3194 }
3195
3196 /**
3197  * This function works like "use VERSION" in Perl, the program will die with a
3198  * backtrace if the current version of PHP is less than the version provided
3199  *
3200  * This is useful for extensions which due to their nature are not kept in sync
3201  * with releases, and might depend on other versions of PHP than the main code
3202  *
3203  * Note: PHP might die due to parsing errors in some cases before it ever
3204  *       manages to call this function, such is life
3205  *
3206  * @see perldoc -f use
3207  *
3208  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3209  * @throws MWException
3210  */
3211 function wfUsePHP( $req_ver ) {
3212         $php_ver = PHP_VERSION;
3213
3214         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3215                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3216         }
3217 }
3218
3219 /**
3220  * This function works like "use VERSION" in Perl except it checks the version
3221  * of MediaWiki, the program will die with a backtrace if the current version
3222  * of MediaWiki is less than the version provided.
3223  *
3224  * This is useful for extensions which due to their nature are not kept in sync
3225  * with releases
3226  *
3227  * Note: Due to the behavior of PHP's version_compare() which is used in this
3228  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3229  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3230  * targeted version number. For example if you wanted to allow any variation
3231  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3232  * not result in the same comparison due to the internal logic of
3233  * version_compare().
3234  *
3235  * @see perldoc -f use
3236  *
3237  * @deprecated since 1.26, use the "requires' property of extension.json
3238  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3239  * @throws MWException
3240  */
3241 function wfUseMW( $req_ver ) {
3242         global $wgVersion;
3243
3244         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3245                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3246         }
3247 }
3248
3249 /**
3250  * Return the final portion of a pathname.
3251  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3252  * http://bugs.php.net/bug.php?id=33898
3253  *
3254  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3255  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3256  *
3257  * @param string $path
3258  * @param string $suffix String to remove if present
3259  * @return string
3260  */
3261 function wfBaseName( $path, $suffix = '' ) {
3262         if ( $suffix == '' ) {
3263                 $encSuffix = '';
3264         } else {
3265                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3266         }
3267
3268         $matches = array();
3269         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3270                 return $matches[1];
3271         } else {
3272                 return '';
3273         }
3274 }
3275
3276 /**
3277  * Generate a relative path name to the given file.
3278  * May explode on non-matching case-insensitive paths,
3279  * funky symlinks, etc.
3280  *
3281  * @param string $path Absolute destination path including target filename
3282  * @param string $from Absolute source path, directory only
3283  * @return string
3284  */
3285 function wfRelativePath( $path, $from ) {
3286         // Normalize mixed input on Windows...
3287         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3288         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3289
3290         // Trim trailing slashes -- fix for drive root
3291         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3292         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3293
3294         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3295         $against = explode( DIRECTORY_SEPARATOR, $from );
3296
3297         if ( $pieces[0] !== $against[0] ) {
3298                 // Non-matching Windows drive letters?
3299                 // Return a full path.
3300                 return $path;
3301         }
3302
3303         // Trim off common prefix
3304         while ( count( $pieces ) && count( $against )
3305                 && $pieces[0] == $against[0] ) {
3306                 array_shift( $pieces );
3307                 array_shift( $against );
3308         }
3309
3310         // relative dots to bump us to the parent
3311         while ( count( $against ) ) {
3312                 array_unshift( $pieces, '..' );
3313                 array_shift( $against );
3314         }
3315
3316         array_push( $pieces, wfBaseName( $path ) );
3317
3318         return implode( DIRECTORY_SEPARATOR, $pieces );
3319 }
3320
3321 /**
3322  * Convert an arbitrarily-long digit string from one numeric base
3323  * to another, optionally zero-padding to a minimum column width.
3324  *
3325  * Supports base 2 through 36; digit values 10-36 are represented
3326  * as lowercase letters a-z. Input is case-insensitive.
3327  *
3328  * @param string $input Input number
3329  * @param int $sourceBase Base of the input number
3330  * @param int $destBase Desired base of the output
3331  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3332  * @param bool $lowercase Whether to output in lowercase or uppercase
3333  * @param string $engine Either "gmp", "bcmath", or "php"
3334  * @return string|bool The output number as a string, or false on error
3335  */
3336 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3337         $lowercase = true, $engine = 'auto'
3338 ) {
3339         $input = (string)$input;
3340         if (
3341                 $sourceBase < 2 ||
3342                 $sourceBase > 36 ||
3343                 $destBase < 2 ||
3344                 $destBase > 36 ||
3345                 $sourceBase != (int)$sourceBase ||
3346                 $destBase != (int)$destBase ||
3347                 $pad != (int)$pad ||
3348                 !preg_match(
3349                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3350                         $input
3351                 )
3352         ) {
3353                 return false;
3354         }
3355
3356         static $baseChars = array(
3357                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3358                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3359                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3360                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3361                 34 => 'y', 35 => 'z',
3362
3363                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3364                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3365                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3366                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3367                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3368                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3369         );
3370
3371         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3372                 // Removing leading zeros works around broken base detection code in
3373                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3374                 // <https://bugs.php.net/bug.php?id=55398>).
3375                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ) ?: '0', $sourceBase ), $destBase );
3376         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3377                 $decimal = '0';
3378                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3379                         $decimal = bcmul( $decimal, $sourceBase );
3380                         $decimal = bcadd( $decimal, $baseChars[$char] );
3381                 }
3382
3383                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3384                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3385                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3386                 }
3387                 // @codingStandardsIgnoreEnd
3388
3389                 $result = strrev( $result );
3390         } else {
3391                 $inDigits = array();
3392                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3393                         $inDigits[] = $baseChars[$char];
3394                 }
3395
3396                 // Iterate over the input, modulo-ing out an output digit
3397                 // at a time until input is gone.
3398                 $result = '';
3399                 while ( $inDigits ) {
3400                         $work = 0;
3401                         $workDigits = array();
3402
3403                         // Long division...
3404                         foreach ( $inDigits as $digit ) {
3405                                 $work *= $sourceBase;
3406                                 $work += $digit;
3407
3408                                 if ( $workDigits || $work >= $destBase ) {
3409                                         $workDigits[] = (int)( $work / $destBase );
3410                                 }
3411                                 $work %= $destBase;
3412                         }
3413
3414                         // All that division leaves us with a remainder,
3415                         // which is conveniently our next output digit.
3416                         $result .= $baseChars[$work];
3417
3418                         // And we continue!
3419                         $inDigits = $workDigits;
3420                 }
3421
3422                 $result = strrev( $result );
3423         }
3424
3425         if ( !$lowercase ) {
3426                 $result = strtoupper( $result );
3427         }
3428
3429         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3430 }
3431
3432 /**
3433  * Check if there is sufficient entropy in php's built-in session generation
3434  *
3435  * @return bool True = there is sufficient entropy
3436  */
3437 function wfCheckEntropy() {
3438         return (
3439                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3440                         || ini_get( 'session.entropy_file' )
3441                 )
3442                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3443 }
3444
3445 /**
3446  * Override session_id before session startup if php's built-in
3447  * session generation code is not secure.
3448  */
3449 function wfFixSessionID() {
3450         // If the cookie or session id is already set we already have a session and should abort
3451         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3452                 return;
3453         }
3454
3455         // PHP's built-in session entropy is enabled if:
3456         // - entropy_file is set or you're on Windows with php 5.3.3+
3457         // - AND entropy_length is > 0
3458         // We treat it as disabled if it doesn't have an entropy length of at least 32
3459         $entropyEnabled = wfCheckEntropy();
3460
3461         // If built-in entropy is not enabled or not sufficient override PHP's
3462         // built in session id generation code
3463         if ( !$entropyEnabled ) {
3464                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3465                         "overriding session id generation using our cryptrand source.\n" );
3466                 session_id( MWCryptRand::generateHex( 32 ) );
3467         }
3468 }
3469
3470 /**
3471  * Reset the session_id
3472  *
3473  * @since 1.22
3474  */
3475 function wfResetSessionID() {
3476         global $wgCookieSecure;
3477         $oldSessionId = session_id();
3478         $cookieParams = session_get_cookie_params();
3479         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3480                 session_regenerate_id( false );
3481         } else {
3482                 $tmp = $_SESSION;
3483                 session_destroy();
3484                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3485                 $_SESSION = $tmp;
3486         }
3487         $newSessionId = session_id();
3488 }
3489
3490 /**
3491  * Initialise php session
3492  *
3493  * @param bool $sessionId
3494  */
3495 function wfSetupSession( $sessionId = false ) {
3496         global $wgSessionsInObjectCache, $wgSessionHandler;
3497         global $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly;
3498
3499         if ( $wgSessionsInObjectCache ) {
3500                 ObjectCacheSessionHandler::install();
3501         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3502                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3503                 # hasn't already been set to the desired value (that causes errors)
3504                 ini_set( 'session.save_handler', $wgSessionHandler );
3505         }
3506
3507         session_set_cookie_params(
3508                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3509         session_cache_limiter( 'private, must-revalidate' );
3510         if ( $sessionId ) {
3511                 session_id( $sessionId );
3512         } else {
3513                 wfFixSessionID();
3514         }
3515
3516         MediaWiki\suppressWarnings();
3517         session_start();
3518         MediaWiki\restoreWarnings();
3519
3520         if ( $wgSessionsInObjectCache ) {
3521                 ObjectCacheSessionHandler::renewCurrentSession();
3522         }
3523 }
3524
3525 /**
3526  * Get an object from the precompiled serialized directory
3527  *
3528  * @param string $name
3529  * @return mixed The variable on success, false on failure
3530  */
3531 function wfGetPrecompiledData( $name ) {
3532         global $IP;
3533
3534         $file = "$IP/serialized/$name";
3535         if ( file_exists( $file ) ) {
3536                 $blob = file_get_contents( $file );
3537                 if ( $blob ) {
3538                         return unserialize( $blob );
3539                 }
3540         }
3541         return false;
3542 }
3543
3544 /**
3545  * Make a cache key for the local wiki.
3546  *
3547  * @param string $args,...
3548  * @return string
3549  */
3550 function wfMemcKey( /*...*/ ) {
3551         return call_user_func_array(
3552                 array( ObjectCache::getLocalClusterInstance(), 'makeKey' ),
3553                 func_get_args()
3554         );
3555 }
3556
3557 /**
3558  * Make a cache key for a foreign DB.
3559  *
3560  * Must match what wfMemcKey() would produce in context of the foreign wiki.
3561  *
3562  * @param string $db
3563  * @param string $prefix
3564  * @param string $args,...
3565  * @return string
3566  */
3567 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3568         $args = array_slice( func_get_args(), 2 );
3569         $keyspace = $prefix ? "$db-$prefix" : $db;
3570         return call_user_func_array(
3571                 array( ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ),
3572                 array( $keyspace, $args )
3573         );
3574 }
3575
3576 /**
3577  * Make a cache key with database-agnostic prefix.
3578  *
3579  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3580  * instead. Must have a prefix as otherwise keys that use a database name
3581  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3582  *
3583  * @since 1.26
3584  * @param string $args,...
3585  * @return string
3586  */
3587 function wfGlobalCacheKey( /*...*/ ) {
3588         return call_user_func_array(
3589                 array( ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ),
3590                 func_get_args()
3591         );
3592 }
3593
3594 /**
3595  * Get an ASCII string identifying this wiki
3596  * This is used as a prefix in memcached keys
3597  *
3598  * @return string
3599  */
3600 function wfWikiID() {
3601         global $wgDBprefix, $wgDBname;
3602         if ( $wgDBprefix ) {
3603                 return "$wgDBname-$wgDBprefix";
3604         } else {
3605                 return $wgDBname;
3606         }
3607 }
3608
3609 /**
3610  * Split a wiki ID into DB name and table prefix
3611  *
3612  * @param string $wiki
3613  *
3614  * @return array
3615  */
3616 function wfSplitWikiID( $wiki ) {
3617         $bits = explode( '-', $wiki, 2 );
3618         if ( count( $bits ) < 2 ) {
3619                 $bits[] = '';
3620         }
3621         return $bits;
3622 }
3623
3624 /**
3625  * Get a Database object.
3626  *
3627  * @param int $db Index of the connection to get. May be DB_MASTER for the
3628  *            master (for write queries), DB_SLAVE for potentially lagged read
3629  *            queries, or an integer >= 0 for a particular server.
3630  *
3631  * @param string|string[] $groups Query groups. An array of group names that this query
3632  *                belongs to. May contain a single string if the query is only
3633  *                in one group.
3634  *
3635  * @param string|bool $wiki The wiki ID, or false for the current wiki
3636  *
3637  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3638  * will always return the same object, unless the underlying connection or load
3639  * balancer is manually destroyed.
3640  *
3641  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3642  * updater to ensure that a proper database is being updated.
3643  *
3644  * @return DatabaseBase
3645  */
3646 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3647         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3648 }
3649
3650 /**
3651  * Get a load balancer object.
3652  *
3653  * @param string|bool $wiki Wiki ID, or false for the current wiki
3654  * @return LoadBalancer
3655  */
3656 function wfGetLB( $wiki = false ) {
3657         return wfGetLBFactory()->getMainLB( $wiki );
3658 }
3659
3660 /**
3661  * Get the load balancer factory object
3662  *
3663  * @return LBFactory
3664  */
3665 function wfGetLBFactory() {
3666         return LBFactory::singleton();
3667 }
3668
3669 /**
3670  * Find a file.
3671  * Shortcut for RepoGroup::singleton()->findFile()
3672  *
3673  * @param string $title String or Title object
3674  * @param array $options Associative array of options (see RepoGroup::findFile)
3675  * @return File|bool File, or false if the file does not exist
3676  */
3677 function wfFindFile( $title, $options = array() ) {
3678         return RepoGroup::singleton()->findFile( $title, $options );
3679 }
3680
3681 /**
3682  * Get an object referring to a locally registered file.
3683  * Returns a valid placeholder object if the file does not exist.
3684  *
3685  * @param Title|string $title
3686  * @return LocalFile|null A File, or null if passed an invalid Title
3687  */
3688 function wfLocalFile( $title ) {
3689         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3690 }
3691
3692 /**
3693  * Should low-performance queries be disabled?
3694  *
3695  * @return bool
3696  * @codeCoverageIgnore
3697  */
3698 function wfQueriesMustScale() {
3699         global $wgMiserMode;
3700         return $wgMiserMode
3701                 || ( SiteStats::pages() > 100000
3702                 && SiteStats::edits() > 1000000
3703                 && SiteStats::users() > 10000 );
3704 }
3705
3706 /**
3707  * Get the path to a specified script file, respecting file
3708  * extensions; this is a wrapper around $wgScriptPath etc.
3709  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3710  *
3711  * @param string $script Script filename, sans extension
3712  * @return string
3713  */
3714 function wfScript( $script = 'index' ) {
3715         global $wgScriptPath, $wgScript, $wgLoadScript;
3716         if ( $script === 'index' ) {
3717                 return $wgScript;
3718         } elseif ( $script === 'load' ) {
3719                 return $wgLoadScript;
3720         } else {
3721                 return "{$wgScriptPath}/{$script}.php";
3722         }
3723 }
3724
3725 /**
3726  * Get the script URL.
3727  *
3728  * @return string Script URL
3729  */
3730 function wfGetScriptUrl() {
3731         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3732                 /* as it was called, minus the query string.
3733                  *
3734                  * Some sites use Apache rewrite rules to handle subdomains,
3735                  * and have PHP set up in a weird way that causes PHP_SELF
3736                  * to contain the rewritten URL instead of the one that the
3737                  * outside world sees.
3738                  *
3739                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
3740                  * provides containing the "before" URL.
3741                  */
3742                 return $_SERVER['SCRIPT_NAME'];
3743         } else {
3744                 return $_SERVER['URL'];
3745         }
3746 }
3747
3748 /**
3749  * Convenience function converts boolean values into "true"
3750  * or "false" (string) values
3751  *
3752  * @param bool $value
3753  * @return string
3754  */
3755 function wfBoolToStr( $value ) {
3756         return $value ? 'true' : 'false';
3757 }
3758
3759 /**
3760  * Get a platform-independent path to the null file, e.g. /dev/null
3761  *
3762  * @return string
3763  */
3764 function wfGetNull() {
3765         return wfIsWindows() ? 'NUL' : '/dev/null';
3766 }
3767
3768 /**
3769  * Waits for the slaves to catch up to the master position
3770  *
3771  * Use this when updating very large numbers of rows, as in maintenance scripts,
3772  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3773  *
3774  * By default this waits on the main DB cluster of the current wiki.
3775  * If $cluster is set to "*" it will wait on all DB clusters, including
3776  * external ones. If the lag being waiting on is caused by the code that
3777  * does this check, it makes since to use $ifWritesSince, particularly if
3778  * cluster is "*", to avoid excess overhead.
3779  *
3780  * Never call this function after a big DB write that is still in a transaction.
3781  * This only makes sense after the possible lag inducing changes were committed.
3782  *
3783  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3784  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3785  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3786  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3787  * @return bool Success (able to connect and no timeouts reached)
3788  */
3789 function wfWaitForSlaves(
3790         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3791 ) {
3792         // B/C: first argument used to be "max seconds of lag"; ignore such values
3793         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3794
3795         if ( $timeout === null ) {
3796                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3797         }
3798
3799         // Figure out which clusters need to be checked
3800         /** @var LoadBalancer[] $lbs */
3801         $lbs = array();
3802         if ( $cluster === '*' ) {
3803                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3804                         $lbs[] = $lb;
3805                 } );
3806         } elseif ( $cluster !== false ) {
3807                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3808         } else {
3809                 $lbs[] = wfGetLB( $wiki );
3810         }
3811
3812         // Get all the master positions of applicable DBs right now.
3813         // This can be faster since waiting on one cluster reduces the
3814         // time needed to wait on the next clusters.
3815         $masterPositions = array_fill( 0, count( $lbs ), false );
3816         foreach ( $lbs as $i => $lb ) {
3817                 if ( $lb->getServerCount() <= 1 ) {
3818                         // Bug 27975 - Don't try to wait for slaves if there are none
3819                         // Prevents permission error when getting master position
3820                         continue;
3821                 } elseif ( $ifWritesSince && $lb->lastMasterChangeTimestamp() < $ifWritesSince ) {
3822                         continue; // no writes since the last wait
3823                 }
3824                 $masterPositions[$i] = $lb->getMasterPos();
3825         }
3826
3827         $ok = true;
3828         foreach ( $lbs as $i => $lb ) {
3829                 if ( $masterPositions[$i] ) {
3830                         // The DBMS may not support getMasterPos() or the whole
3831                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3832                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3833                 }
3834         }
3835
3836         return $ok;
3837 }
3838
3839 /**
3840  * Count down from $seconds to zero on the terminal, with a one-second pause
3841  * between showing each number. For use in command-line scripts.
3842  *
3843  * @codeCoverageIgnore
3844  * @param int $seconds
3845  */
3846 function wfCountDown( $seconds ) {
3847         for ( $i = $seconds; $i >= 0; $i-- ) {
3848                 if ( $i != $seconds ) {
3849                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3850                 }
3851                 echo $i;
3852                 flush();
3853                 if ( $i ) {
3854                         sleep( 1 );
3855                 }
3856         }
3857         echo "\n";
3858 }
3859
3860 /**
3861  * Replace all invalid characters with -
3862  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3863  * By default, $wgIllegalFileChars = ':'
3864  *
3865  * @param string $name Filename to process
3866  * @return string
3867  */
3868 function wfStripIllegalFilenameChars( $name ) {
3869         global $wgIllegalFileChars;
3870         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3871         $name = wfBaseName( $name );
3872         $name = preg_replace(
3873                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3874                 '-',
3875                 $name
3876         );
3877         return $name;
3878 }
3879
3880 /**
3881  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3882  *
3883  * @return int Resulting value of the memory limit.
3884  */
3885 function wfMemoryLimit() {
3886         global $wgMemoryLimit;
3887         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3888         if ( $memlimit != -1 ) {
3889                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3890                 if ( $conflimit == -1 ) {
3891                         wfDebug( "Removing PHP's memory limit\n" );
3892                         MediaWiki\suppressWarnings();
3893                         ini_set( 'memory_limit', $conflimit );
3894                         MediaWiki\restoreWarnings();
3895                         return $conflimit;
3896                 } elseif ( $conflimit > $memlimit ) {
3897                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3898                         MediaWiki\suppressWarnings();
3899                         ini_set( 'memory_limit', $conflimit );
3900                         MediaWiki\restoreWarnings();
3901                         return $conflimit;
3902                 }
3903         }
3904         return $memlimit;
3905 }
3906
3907 /**
3908  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3909  *
3910  * @return int Prior time limit
3911  * @since 1.26
3912  */
3913 function wfTransactionalTimeLimit() {
3914         global $wgTransactionalTimeLimit;
3915
3916         $timeLimit = ini_get( 'max_execution_time' );
3917         // Note that CLI scripts use 0
3918         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3919                 set_time_limit( $wgTransactionalTimeLimit );
3920         }
3921
3922         ignore_user_abort( true ); // ignore client disconnects
3923
3924         return $timeLimit;
3925 }
3926
3927 /**
3928  * Converts shorthand byte notation to integer form
3929  *
3930  * @param string $string
3931  * @param int $default Returned if $string is empty
3932  * @return int
3933  */
3934 function wfShorthandToInteger( $string = '', $default = -1 ) {
3935         $string = trim( $string );
3936         if ( $string === '' ) {
3937                 return $default;
3938         }
3939         $last = $string[strlen( $string ) - 1];
3940         $val = intval( $string );
3941         switch ( $last ) {
3942                 case 'g':
3943                 case 'G':
3944                         $val *= 1024;
3945                         // break intentionally missing
3946                 case 'm':
3947                 case 'M':
3948                         $val *= 1024;
3949                         // break intentionally missing
3950                 case 'k':
3951                 case 'K':
3952                         $val *= 1024;
3953         }
3954
3955         return $val;
3956 }
3957
3958 /**
3959  * Get the normalised IETF language tag
3960  * See unit test for examples.
3961  *
3962  * @param string $code The language code.
3963  * @return string The language code which complying with BCP 47 standards.
3964  */
3965 function wfBCP47( $code ) {
3966         $codeSegment = explode( '-', $code );
3967         $codeBCP = array();
3968         foreach ( $codeSegment as $segNo => $seg ) {
3969                 // when previous segment is x, it is a private segment and should be lc
3970                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3971                         $codeBCP[$segNo] = strtolower( $seg );
3972                 // ISO 3166 country code
3973                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3974                         $codeBCP[$segNo] = strtoupper( $seg );
3975                 // ISO 15924 script code
3976                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3977                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3978                 // Use lowercase for other cases
3979                 } else {
3980                         $codeBCP[$segNo] = strtolower( $seg );
3981                 }
3982         }
3983         $langCode = implode( '-', $codeBCP );
3984         return $langCode;
3985 }
3986
3987 /**
3988  * Get a specific cache object.
3989  *
3990  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3991  * @return BagOStuff
3992  */
3993 function wfGetCache( $cacheType ) {
3994         return ObjectCache::getInstance( $cacheType );
3995 }
3996
3997 /**
3998  * Get the main cache object
3999  *
4000  * @return BagOStuff
4001  */
4002 function wfGetMainCache() {
4003         global $wgMainCacheType;
4004         return ObjectCache::getInstance( $wgMainCacheType );
4005 }
4006
4007 /**
4008  * Get the cache object used by the message cache
4009  *
4010  * @return BagOStuff
4011  */
4012 function wfGetMessageCacheStorage() {
4013         global $wgMessageCacheType;
4014         return ObjectCache::getInstance( $wgMessageCacheType );
4015 }
4016
4017 /**
4018  * Get the cache object used by the parser cache
4019  *
4020  * @return BagOStuff
4021  */
4022 function wfGetParserCacheStorage() {
4023         global $wgParserCacheType;
4024         return ObjectCache::getInstance( $wgParserCacheType );
4025 }
4026
4027 /**
4028  * Call hook functions defined in $wgHooks
4029  *
4030  * @param string $event Event name
4031  * @param array $args Parameters passed to hook functions
4032  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
4033  *
4034  * @return bool True if no handler aborted the hook
4035  * @deprecated 1.25 - use Hooks::run
4036  */
4037 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
4038         return Hooks::run( $event, $args, $deprecatedVersion );
4039 }
4040
4041 /**
4042  * Wrapper around php's unpack.
4043  *
4044  * @param string $format The format string (See php's docs)
4045  * @param string $data A binary string of binary data
4046  * @param int|bool $length The minimum length of $data or false. This is to
4047  *      prevent reading beyond the end of $data. false to disable the check.
4048  *
4049  * Also be careful when using this function to read unsigned 32 bit integer
4050  * because php might make it negative.
4051  *
4052  * @throws MWException If $data not long enough, or if unpack fails
4053  * @return array Associative array of the extracted data
4054  */
4055 function wfUnpack( $format, $data, $length = false ) {
4056         if ( $length !== false ) {
4057                 $realLen = strlen( $data );
4058                 if ( $realLen < $length ) {
4059                         throw new MWException( "Tried to use wfUnpack on a "
4060                                 . "string of length $realLen, but needed one "
4061                                 . "of at least length $length."
4062                         );
4063                 }
4064         }
4065
4066         MediaWiki\suppressWarnings();
4067         $result = unpack( $format, $data );
4068         MediaWiki\restoreWarnings();
4069
4070         if ( $result === false ) {
4071                 // If it cannot extract the packed data.
4072                 throw new MWException( "unpack could not unpack binary data" );
4073         }
4074         return $result;
4075 }
4076
4077 /**
4078  * Determine if an image exists on the 'bad image list'.
4079  *
4080  * The format of MediaWiki:Bad_image_list is as follows:
4081  *    * Only list items (lines starting with "*") are considered
4082  *    * The first link on a line must be a link to a bad image
4083  *    * Any subsequent links on the same line are considered to be exceptions,
4084  *      i.e. articles where the image may occur inline.
4085  *
4086  * @param string $name The image name to check
4087  * @param Title|bool $contextTitle The page on which the image occurs, if known
4088  * @param string $blacklist Wikitext of a file blacklist
4089  * @return bool
4090  */
4091 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4092         # Handle redirects; callers almost always hit wfFindFile() anyway,
4093         # so just use that method because it has a fast process cache.
4094         $file = wfFindFile( $name ); // get the final name
4095         $name = $file ? $file->getTitle()->getDBkey() : $name;
4096
4097         # Run the extension hook
4098         $bad = false;
4099         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4100                 return $bad;
4101         }
4102
4103         $cache = ObjectCache::newAccelerator( 'hash' );
4104         $key = wfMemcKey( 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist ) );
4105         $badImages = $cache->get( $key );
4106
4107         if ( $badImages === false ) { // cache miss
4108                 if ( $blacklist === null ) {
4109                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4110                 }
4111                 # Build the list now
4112                 $badImages = array();
4113                 $lines = explode( "\n", $blacklist );
4114                 foreach ( $lines as $line ) {
4115                         # List items only
4116                         if ( substr( $line, 0, 1 ) !== '*' ) {
4117                                 continue;
4118                         }
4119
4120                         # Find all links
4121                         $m = array();
4122                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4123                                 continue;
4124                         }
4125
4126                         $exceptions = array();
4127                         $imageDBkey = false;
4128                         foreach ( $m[1] as $i => $titleText ) {
4129                                 $title = Title::newFromText( $titleText );
4130                                 if ( !is_null( $title ) ) {
4131                                         if ( $i == 0 ) {
4132                                                 $imageDBkey = $title->getDBkey();
4133                                         } else {
4134                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4135                                         }
4136                                 }
4137                         }
4138
4139                         if ( $imageDBkey !== false ) {
4140                                 $badImages[$imageDBkey] = $exceptions;
4141                         }
4142                 }
4143                 $cache->set( $key, $badImages, 60 );
4144         }
4145
4146         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4147         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4148
4149         return $bad;
4150 }
4151
4152 /**
4153  * Determine whether the client at a given source IP is likely to be able to
4154  * access the wiki via HTTPS.
4155  *
4156  * @param string $ip The IPv4/6 address in the normal human-readable form
4157  * @return bool
4158  */
4159 function wfCanIPUseHTTPS( $ip ) {
4160         $canDo = true;
4161         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4162         return !!$canDo;
4163 }
4164
4165 /**
4166  * Determine input string is represents as infinity
4167  *
4168  * @param string $str The string to determine
4169  * @return bool
4170  * @since 1.25
4171  */
4172 function wfIsInfinity( $str ) {
4173         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4174         return in_array( $str, $infinityValues );
4175 }
4176
4177 /**
4178  * Work out the IP address based on various globals
4179  * For trusted proxies, use the XFF client IP (first of the chain)
4180  *
4181  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4182  * @return string
4183  */
4184 function wfGetIP() {
4185         wfDeprecated( __METHOD__, '1.19' );
4186         global $wgRequest;
4187         return $wgRequest->getIP();
4188 }
4189
4190 /**
4191  * Checks if an IP is a trusted proxy provider.
4192  * Useful to tell if X-Forwarded-For data is possibly bogus.
4193  * Squid cache servers for the site are whitelisted.
4194  * @deprecated Since 1.24, use IP::isTrustedProxy()
4195  *
4196  * @param string $ip
4197  * @return bool
4198  */
4199 function wfIsTrustedProxy( $ip ) {
4200         wfDeprecated( __METHOD__, '1.24' );
4201         return IP::isTrustedProxy( $ip );
4202 }
4203
4204 /**
4205  * Checks if an IP matches a proxy we've configured.
4206  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4207  *
4208  * @param string $ip
4209  * @return bool
4210  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4211  */
4212 function wfIsConfiguredProxy( $ip ) {
4213         wfDeprecated( __METHOD__, '1.24' );
4214         return IP::isConfiguredProxy( $ip );
4215 }
4216
4217 /**
4218  * Returns true if these thumbnail parameters match one that MediaWiki
4219  * requests from file description pages and/or parser output.
4220  *
4221  * $params is considered non-standard if they involve a non-standard
4222  * width or any non-default parameters aside from width and page number.
4223  * The number of possible files with standard parameters is far less than
4224  * that of all combinations; rate-limiting for them can thus be more generious.
4225  *
4226  * @param File $file
4227  * @param array $params
4228  * @return bool
4229  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4230  */
4231 function wfThumbIsStandard( File $file, array $params ) {
4232         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4233
4234         $multipliers = array( 1 );
4235         if ( $wgResponsiveImages ) {
4236                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4237                 // @see Linker::processResponsiveImages
4238                 $multipliers[] = 1.5;
4239                 $multipliers[] = 2;
4240         }
4241
4242         $handler = $file->getHandler();
4243         if ( !$handler || !isset( $params['width'] ) ) {
4244                 return false;
4245         }
4246
4247         $basicParams = array();
4248         if ( isset( $params['page'] ) ) {
4249                 $basicParams['page'] = $params['page'];
4250         }
4251
4252         $thumbLimits = array();
4253         $imageLimits = array();
4254         // Expand limits to account for multipliers
4255         foreach ( $multipliers as $multiplier ) {
4256                 $thumbLimits = array_merge( $thumbLimits, array_map(
4257                         function ( $width ) use ( $multiplier ) {
4258                                 return round( $width * $multiplier );
4259                         }, $wgThumbLimits )
4260                 );
4261                 $imageLimits = array_merge( $imageLimits, array_map(
4262                         function ( $pair ) use ( $multiplier ) {
4263                                 return array(
4264                                         round( $pair[0] * $multiplier ),
4265                                         round( $pair[1] * $multiplier ),
4266                                 );
4267                         }, $wgImageLimits )
4268                 );
4269         }
4270
4271         // Check if the width matches one of $wgThumbLimits
4272         if ( in_array( $params['width'], $thumbLimits ) ) {
4273                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4274                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4275                 $handler->normaliseParams( $file, $normalParams );
4276         } else {
4277                 // If not, then check if the width matchs one of $wgImageLimits
4278                 $match = false;
4279                 foreach ( $imageLimits as $pair ) {
4280                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4281                         // Decide whether the thumbnail should be scaled on width or height.
4282                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4283                         $handler->normaliseParams( $file, $normalParams );
4284                         // Check if this standard thumbnail size maps to the given width
4285                         if ( $normalParams['width'] == $params['width'] ) {
4286                                 $match = true;
4287                                 break;
4288                         }
4289                 }
4290                 if ( !$match ) {
4291                         return false; // not standard for description pages
4292                 }
4293         }
4294
4295         // Check that the given values for non-page, non-width, params are just defaults
4296         foreach ( $params as $key => $value ) {
4297                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4298                         return false;
4299                 }
4300         }
4301
4302         return true;
4303 }
4304
4305 /**
4306  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
4307  *
4308  * Values that exist in both values will be combined with += (all values of the array
4309  * of $newValues will be added to the values of the array of $baseArray, while values,
4310  * that exists in both, the value of $baseArray will be used).
4311  *
4312  * @param array $baseArray The array where you want to add the values of $newValues to
4313  * @param array $newValues An array with new values
4314  * @return array The combined array
4315  * @since 1.26
4316  */
4317 function wfArrayPlus2d( array $baseArray, array $newValues ) {
4318         // First merge items that are in both arrays
4319         foreach ( $baseArray as $name => &$groupVal ) {
4320                 if ( isset( $newValues[$name] ) ) {
4321                         $groupVal += $newValues[$name];
4322                 }
4323         }
4324         // Now add items that didn't exist yet
4325         $baseArray += $newValues;
4326
4327         return $baseArray;
4328 }