includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 use Liuggio\StatsdClient\Sender\SocketSender;
  28 use MediaWiki\Logger\LoggerFactory;
  29 use MediaWiki\Session\SessionManager;
  30
  31 // Hide compatibility functions from Doxygen
  32 /// @cond
  33 /**
  34  * Compatibility functions
  35  *
  36  * We support PHP 5.5.9 and up.
  37  * Re-implementations of newer functions or functions in non-standard
  38  * PHP extensions may be included here.
  39  */
  40
  41 // hash_equals function only exists in PHP >= 5.6.0
  42 // http://php.net/hash_equals
  43 if ( !function_exists( 'hash_equals' ) ) {
  44         /**
  45          * Check whether a user-provided string is equal to a fixed-length secret string
  46          * without revealing bytes of the secret string through timing differences.
  47          *
  48          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
  49          * function in C) is to compare corresponding bytes and stop at the first difference,
  50          * which would take longer for a partial match than for a complete mismatch. This
  51          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
  52          * and the other may come from an attacker. Statistical analysis of timing measurements
  53          * over many requests may allow the attacker to guess the string's bytes one at a time
  54          * (and check his guesses) even if the timing differences are extremely small.
  55          *
  56          * When making such a security-sensitive comparison, it is essential that the sequence
  57          * in which instructions are executed and memory locations are accessed not depend on
  58          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
  59          * the inevitable leakage of the string's length. That is generally known anyway as
  60          * a chararacteristic of the hash function used to compute the secret value.
  61          *
  62          * Longer explanation: http://www.emerose.com/timing-attacks-explained
  63          *
  64          * @codeCoverageIgnore
  65          * @param string $known_string Fixed-length secret string to compare against
  66          * @param string $user_string User-provided string
  67          * @return bool True if the strings are the same, false otherwise
  68          */
  69         function hash_equals( $known_string, $user_string ) {
  70                 // Strict type checking as in PHP's native implementation
  71                 if ( !is_string( $known_string ) ) {
  72                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
  73                                 gettype( $known_string ) . ' given', E_USER_WARNING );
  74
  75                         return false;
  76                 }
  77
  78                 if ( !is_string( $user_string ) ) {
  79                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
  80                                 gettype( $user_string ) . ' given', E_USER_WARNING );
  81
  82                         return false;
  83                 }
  84
  85                 $known_string_len = strlen( $known_string );
  86                 if ( $known_string_len !== strlen( $user_string ) ) {
  87                         return false;
  88                 }
  89
  90                 $result = 0;
  91                 for ( $i = 0; $i < $known_string_len; $i++ ) {
  92                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
  93                 }
  94
  95                 return ( $result === 0 );
  96         }
  97 }
  98 /// @endcond
  99
 100 /**
 101  * Load an extension
 102  *
 103  * This queues an extension to be loaded through
 104  * the ExtensionRegistry system.
 105  *
 106  * @param string $ext Name of the extension to load
 107  * @param string|null $path Absolute path of where to find the extension.json file
 108  * @since 1.25
 109  */
 110 function wfLoadExtension( $ext, $path = null ) {
 111         if ( !$path ) {
 112                 global $wgExtensionDirectory;
 113                 $path = "$wgExtensionDirectory/$ext/extension.json";
 114         }
 115         ExtensionRegistry::getInstance()->queue( $path );
 116 }
 117
 118 /**
 119  * Load multiple extensions at once
 120  *
 121  * Same as wfLoadExtension, but more efficient if you
 122  * are loading multiple extensions.
 123  *
 124  * If you want to specify custom paths, you should interact with
 125  * ExtensionRegistry directly.
 126  *
 127  * @see wfLoadExtension
 128  * @param string[] $exts Array of extension names to load
 129  * @since 1.25
 130  */
 131 function wfLoadExtensions( array $exts ) {
 132         global $wgExtensionDirectory;
 133         $registry = ExtensionRegistry::getInstance();
 134         foreach ( $exts as $ext ) {
 135                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 136         }
 137 }
 138
 139 /**
 140  * Load a skin
 141  *
 142  * @see wfLoadExtension
 143  * @param string $skin Name of the extension to load
 144  * @param string|null $path Absolute path of where to find the skin.json file
 145  * @since 1.25
 146  */
 147 function wfLoadSkin( $skin, $path = null ) {
 148         if ( !$path ) {
 149                 global $wgStyleDirectory;
 150                 $path = "$wgStyleDirectory/$skin/skin.json";
 151         }
 152         ExtensionRegistry::getInstance()->queue( $path );
 153 }
 154
 155 /**
 156  * Load multiple skins at once
 157  *
 158  * @see wfLoadExtensions
 159  * @param string[] $skins Array of extension names to load
 160  * @since 1.25
 161  */
 162 function wfLoadSkins( array $skins ) {
 163         global $wgStyleDirectory;
 164         $registry = ExtensionRegistry::getInstance();
 165         foreach ( $skins as $skin ) {
 166                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 167         }
 168 }
 169
 170 /**
 171  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 172  * @param array $a
 173  * @param array $b
 174  * @return array
 175  */
 176 function wfArrayDiff2( $a, $b ) {
 177         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 178 }
 179
 180 /**
 181  * @param array|string $a
 182  * @param array|string $b
 183  * @return int
 184  */
 185 function wfArrayDiff2_cmp( $a, $b ) {
 186         if ( is_string( $a ) && is_string( $b ) ) {
 187                 return strcmp( $a, $b );
 188         } elseif ( count( $a ) !== count( $b ) ) {
 189                 return count( $a ) < count( $b ) ? -1 : 1;
 190         } else {
 191                 reset( $a );
 192                 reset( $b );
 193                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 194                         $cmp = strcmp( $valueA, $valueB );
 195                         if ( $cmp !== 0 ) {
 196                                 return $cmp;
 197                         }
 198                 }
 199                 return 0;
 200         }
 201 }
 202
 203 /**
 204  * Appends to second array if $value differs from that in $default
 205  *
 206  * @param string|int $key
 207  * @param mixed $value
 208  * @param mixed $default
 209  * @param array $changed Array to alter
 210  * @throws MWException
 211  */
 212 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 213         if ( is_null( $changed ) ) {
 214                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 215         }
 216         if ( $default[$key] !== $value ) {
 217                 $changed[$key] = $value;
 218         }
 219 }
 220
 221 /**
 222  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 223  * e.g.
 224  *      wfMergeErrorArrays(
 225  *              [ [ 'x' ] ],
 226  *              [ [ 'x', '2' ] ],
 227  *              [ [ 'x' ] ],
 228  *              [ [ 'y' ] ]
 229  *      );
 230  * returns:
 231  *              [
 232  *              [ 'x', '2' ],
 233  *              [ 'x' ],
 234  *              [ 'y' ]
 235  *      ]
 236  *
 237  * @param array $array1,...
 238  * @return array
 239  */
 240 function wfMergeErrorArrays( /*...*/ ) {
 241         $args = func_get_args();
 242         $out = [];
 243         foreach ( $args as $errors ) {
 244                 foreach ( $errors as $params ) {
 245                         $originalParams = $params;
 246                         if ( $params[0] instanceof MessageSpecifier ) {
 247                                 $msg = $params[0];
 248                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 249                         }
 250                         # @todo FIXME: Sometimes get nested arrays for $params,
 251                         # which leads to E_NOTICEs
 252                         $spec = implode( "\t", $params );
 253                         $out[$spec] = $originalParams;
 254                 }
 255         }
 256         return array_values( $out );
 257 }
 258
 259 /**
 260  * Insert array into another array after the specified *KEY*
 261  *
 262  * @param array $array The array.
 263  * @param array $insert The array to insert.
 264  * @param mixed $after The key to insert after
 265  * @return array
 266  */
 267 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 268         // Find the offset of the element to insert after.
 269         $keys = array_keys( $array );
 270         $offsetByKey = array_flip( $keys );
 271
 272         $offset = $offsetByKey[$after];
 273
 274         // Insert at the specified offset
 275         $before = array_slice( $array, 0, $offset + 1, true );
 276         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 277
 278         $output = $before + $insert + $after;
 279
 280         return $output;
 281 }
 282
 283 /**
 284  * Recursively converts the parameter (an object) to an array with the same data
 285  *
 286  * @param object|array $objOrArray
 287  * @param bool $recursive
 288  * @return array
 289  */
 290 function wfObjectToArray( $objOrArray, $recursive = true ) {
 291         $array = [];
 292         if ( is_object( $objOrArray ) ) {
 293                 $objOrArray = get_object_vars( $objOrArray );
 294         }
 295         foreach ( $objOrArray as $key => $value ) {
 296                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 297                         $value = wfObjectToArray( $value );
 298                 }
 299
 300                 $array[$key] = $value;
 301         }
 302
 303         return $array;
 304 }
 305
 306 /**
 307  * Get a random decimal value between 0 and 1, in a way
 308  * not likely to give duplicate values for any realistic
 309  * number of articles.
 310  *
 311  * @note This is designed for use in relation to Special:RandomPage
 312  *       and the page_random database field.
 313  *
 314  * @return string
 315  */
 316 function wfRandom() {
 317         // The maximum random value is "only" 2^31-1, so get two random
 318         // values to reduce the chance of dupes
 319         $max = mt_getrandmax() + 1;
 320         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 321         return $rand;
 322 }
 323
 324 /**
 325  * Get a random string containing a number of pseudo-random hex characters.
 326  *
 327  * @note This is not secure, if you are trying to generate some sort
 328  *       of token please use MWCryptRand instead.
 329  *
 330  * @param int $length The length of the string to generate
 331  * @return string
 332  * @since 1.20
 333  */
 334 function wfRandomString( $length = 32 ) {
 335         $str = '';
 336         for ( $n = 0; $n < $length; $n += 7 ) {
 337                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 338         }
 339         return substr( $str, 0, $length );
 340 }
 341
 342 /**
 343  * We want some things to be included as literal characters in our title URLs
 344  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 345  * all of the following should be safe:
 346  *
 347  * ;:@&=$-_.+!*'(),
 348  *
 349  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 350  * character which should not be encoded. More importantly, google chrome
 351  * always converts %7E back to ~, and converting it in this function can
 352  * cause a redirect loop (T105265).
 353  *
 354  * But + is not safe because it's used to indicate a space; &= are only safe in
 355  * paths and not in queries (and we don't distinguish here); ' seems kind of
 356  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 357  * is reserved, we don't care.  So the list we unescape is:
 358  *
 359  * ;:@$!*(),/~
 360  *
 361  * However, IIS7 redirects fail when the url contains a colon (see T24709),
 362  * so no fancy : for IIS7.
 363  *
 364  * %2F in the page titles seems to fatally break for some reason.
 365  *
 366  * @param string $s
 367  * @return string
 368  */
 369 function wfUrlencode( $s ) {
 370         static $needle;
 371
 372         if ( is_null( $s ) ) {
 373                 $needle = null;
 374                 return '';
 375         }
 376
 377         if ( is_null( $needle ) ) {
 378                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 379                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 380                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 381                 ) {
 382                         $needle[] = '%3A';
 383                 }
 384         }
 385
 386         $s = urlencode( $s );
 387         $s = str_ireplace(
 388                 $needle,
 389                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 390                 $s
 391         );
 392
 393         return $s;
 394 }
 395
 396 /**
 397  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 398  * "days=7&limit=100". Options in the first array override options in the second.
 399  * Options set to null or false will not be output.
 400  *
 401  * @param array $array1 ( String|Array )
 402  * @param array|null $array2 ( String|Array )
 403  * @param string $prefix
 404  * @return string
 405  */
 406 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 407         if ( !is_null( $array2 ) ) {
 408                 $array1 = $array1 + $array2;
 409         }
 410
 411         $cgi = '';
 412         foreach ( $array1 as $key => $value ) {
 413                 if ( !is_null( $value ) && $value !== false ) {
 414                         if ( $cgi != '' ) {
 415                                 $cgi .= '&';
 416                         }
 417                         if ( $prefix !== '' ) {
 418                                 $key = $prefix . "[$key]";
 419                         }
 420                         if ( is_array( $value ) ) {
 421                                 $firstTime = true;
 422                                 foreach ( $value as $k => $v ) {
 423                                         $cgi .= $firstTime ? '' : '&';
 424                                         if ( is_array( $v ) ) {
 425                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 426                                         } else {
 427                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 428                                         }
 429                                         $firstTime = false;
 430                                 }
 431                         } else {
 432                                 if ( is_object( $value ) ) {
 433                                         $value = $value->__toString();
 434                                 }
 435                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 436                         }
 437                 }
 438         }
 439         return $cgi;
 440 }
 441
 442 /**
 443  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 444  * its argument and returns the same string in array form.  This allows compatibility
 445  * with legacy functions that accept raw query strings instead of nice
 446  * arrays.  Of course, keys and values are urldecode()d.
 447  *
 448  * @param string $query Query string
 449  * @return string[] Array version of input
 450  */
 451 function wfCgiToArray( $query ) {
 452         if ( isset( $query[0] ) && $query[0] == '?' ) {
 453                 $query = substr( $query, 1 );
 454         }
 455         $bits = explode( '&', $query );
 456         $ret = [];
 457         foreach ( $bits as $bit ) {
 458                 if ( $bit === '' ) {
 459                         continue;
 460                 }
 461                 if ( strpos( $bit, '=' ) === false ) {
 462                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 463                         $key = $bit;
 464                         $value = '';
 465                 } else {
 466                         list( $key, $value ) = explode( '=', $bit );
 467                 }
 468                 $key = urldecode( $key );
 469                 $value = urldecode( $value );
 470                 if ( strpos( $key, '[' ) !== false ) {
 471                         $keys = array_reverse( explode( '[', $key ) );
 472                         $key = array_pop( $keys );
 473                         $temp = $value;
 474                         foreach ( $keys as $k ) {
 475                                 $k = substr( $k, 0, -1 );
 476                                 $temp = [ $k => $temp ];
 477                         }
 478                         if ( isset( $ret[$key] ) ) {
 479                                 $ret[$key] = array_merge( $ret[$key], $temp );
 480                         } else {
 481                                 $ret[$key] = $temp;
 482                         }
 483                 } else {
 484                         $ret[$key] = $value;
 485                 }
 486         }
 487         return $ret;
 488 }
 489
 490 /**
 491  * Append a query string to an existing URL, which may or may not already
 492  * have query string parameters already. If so, they will be combined.
 493  *
 494  * @param string $url
 495  * @param string|string[] $query String or associative array
 496  * @return string
 497  */
 498 function wfAppendQuery( $url, $query ) {
 499         if ( is_array( $query ) ) {
 500                 $query = wfArrayToCgi( $query );
 501         }
 502         if ( $query != '' ) {
 503                 // Remove the fragment, if there is one
 504                 $fragment = false;
 505                 $hashPos = strpos( $url, '#' );
 506                 if ( $hashPos !== false ) {
 507                         $fragment = substr( $url, $hashPos );
 508                         $url = substr( $url, 0, $hashPos );
 509                 }
 510
 511                 // Add parameter
 512                 if ( false === strpos( $url, '?' ) ) {
 513                         $url .= '?';
 514                 } else {
 515                         $url .= '&';
 516                 }
 517                 $url .= $query;
 518
 519                 // Put the fragment back
 520                 if ( $fragment !== false ) {
 521                         $url .= $fragment;
 522                 }
 523         }
 524         return $url;
 525 }
 526
 527 /**
 528  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 529  * is correct.
 530  *
 531  * The meaning of the PROTO_* constants is as follows:
 532  * PROTO_HTTP: Output a URL starting with http://
 533  * PROTO_HTTPS: Output a URL starting with https://
 534  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 535  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 536  *    on which protocol was used for the current incoming request
 537  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 538  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 539  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 540  *
 541  * @todo this won't work with current-path-relative URLs
 542  * like "subdir/foo.html", etc.
 543  *
 544  * @param string $url Either fully-qualified or a local path + query
 545  * @param string $defaultProto One of the PROTO_* constants. Determines the
 546  *    protocol to use if $url or $wgServer is protocol-relative
 547  * @return string Fully-qualified URL, current-path-relative URL or false if
 548  *    no valid URL can be constructed
 549  */
 550 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 551         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 552                 $wgHttpsPort;
 553         if ( $defaultProto === PROTO_CANONICAL ) {
 554                 $serverUrl = $wgCanonicalServer;
 555         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 556                 // Make $wgInternalServer fall back to $wgServer if not set
 557                 $serverUrl = $wgInternalServer;
 558         } else {
 559                 $serverUrl = $wgServer;
 560                 if ( $defaultProto === PROTO_CURRENT ) {
 561                         $defaultProto = $wgRequest->getProtocol() . '://';
 562                 }
 563         }
 564
 565         // Analyze $serverUrl to obtain its protocol
 566         $bits = wfParseUrl( $serverUrl );
 567         $serverHasProto = $bits && $bits['scheme'] != '';
 568
 569         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 570                 if ( $serverHasProto ) {
 571                         $defaultProto = $bits['scheme'] . '://';
 572                 } else {
 573                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 574                         // This really isn't supposed to happen. Fall back to HTTP in this
 575                         // ridiculous case.
 576                         $defaultProto = PROTO_HTTP;
 577                 }
 578         }
 579
 580         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 581
 582         if ( substr( $url, 0, 2 ) == '//' ) {
 583                 $url = $defaultProtoWithoutSlashes . $url;
 584         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 585                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 586                 // otherwise leave it alone.
 587                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 588         }
 589
 590         $bits = wfParseUrl( $url );
 591
 592         // ensure proper port for HTTPS arrives in URL
 593         // https://phabricator.wikimedia.org/T67184
 594         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 595                 $bits['port'] = $wgHttpsPort;
 596         }
 597
 598         if ( $bits && isset( $bits['path'] ) ) {
 599                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 600                 return wfAssembleUrl( $bits );
 601         } elseif ( $bits ) {
 602                 # No path to expand
 603                 return $url;
 604         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 605                 # URL is a relative path
 606                 return wfRemoveDotSegments( $url );
 607         }
 608
 609         # Expanded URL is not valid.
 610         return false;
 611 }
 612
 613 /**
 614  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 615  * if you need to edit part of a URL and put it back together.
 616  *
 617  * This is the basic structure used (brackets contain keys for $urlParts):
 618  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 619  *
 620  * @todo Need to integrate this into wfExpandUrl (see T34168)
 621  *
 622  * @since 1.19
 623  * @param array $urlParts URL parts, as output from wfParseUrl
 624  * @return string URL assembled from its component parts
 625  */
 626 function wfAssembleUrl( $urlParts ) {
 627         $result = '';
 628
 629         if ( isset( $urlParts['delimiter'] ) ) {
 630                 if ( isset( $urlParts['scheme'] ) ) {
 631                         $result .= $urlParts['scheme'];
 632                 }
 633
 634                 $result .= $urlParts['delimiter'];
 635         }
 636
 637         if ( isset( $urlParts['host'] ) ) {
 638                 if ( isset( $urlParts['user'] ) ) {
 639                         $result .= $urlParts['user'];
 640                         if ( isset( $urlParts['pass'] ) ) {
 641                                 $result .= ':' . $urlParts['pass'];
 642                         }
 643                         $result .= '@';
 644                 }
 645
 646                 $result .= $urlParts['host'];
 647
 648                 if ( isset( $urlParts['port'] ) ) {
 649                         $result .= ':' . $urlParts['port'];
 650                 }
 651         }
 652
 653         if ( isset( $urlParts['path'] ) ) {
 654                 $result .= $urlParts['path'];
 655         }
 656
 657         if ( isset( $urlParts['query'] ) ) {
 658                 $result .= '?' . $urlParts['query'];
 659         }
 660
 661         if ( isset( $urlParts['fragment'] ) ) {
 662                 $result .= '#' . $urlParts['fragment'];
 663         }
 664
 665         return $result;
 666 }
 667
 668 /**
 669  * Remove all dot-segments in the provided URL path.  For example,
 670  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 671  * RFC3986 section 5.2.4.
 672  *
 673  * @todo Need to integrate this into wfExpandUrl (see T34168)
 674  *
 675  * @param string $urlPath URL path, potentially containing dot-segments
 676  * @return string URL path with all dot-segments removed
 677  */
 678 function wfRemoveDotSegments( $urlPath ) {
 679         $output = '';
 680         $inputOffset = 0;
 681         $inputLength = strlen( $urlPath );
 682
 683         while ( $inputOffset < $inputLength ) {
 684                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 685                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 686                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 687                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 688                 $trimOutput = false;
 689
 690                 if ( $prefixLengthTwo == './' ) {
 691                         # Step A, remove leading "./"
 692                         $inputOffset += 2;
 693                 } elseif ( $prefixLengthThree == '../' ) {
 694                         # Step A, remove leading "../"
 695                         $inputOffset += 3;
 696                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 697                         # Step B, replace leading "/.$" with "/"
 698                         $inputOffset += 1;
 699                         $urlPath[$inputOffset] = '/';
 700                 } elseif ( $prefixLengthThree == '/./' ) {
 701                         # Step B, replace leading "/./" with "/"
 702                         $inputOffset += 2;
 703                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 704                         # Step C, replace leading "/..$" with "/" and
 705                         # remove last path component in output
 706                         $inputOffset += 2;
 707                         $urlPath[$inputOffset] = '/';
 708                         $trimOutput = true;
 709                 } elseif ( $prefixLengthFour == '/../' ) {
 710                         # Step C, replace leading "/../" with "/" and
 711                         # remove last path component in output
 712                         $inputOffset += 3;
 713                         $trimOutput = true;
 714                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 715                         # Step D, remove "^.$"
 716                         $inputOffset += 1;
 717                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 718                         # Step D, remove "^..$"
 719                         $inputOffset += 2;
 720                 } else {
 721                         # Step E, move leading path segment to output
 722                         if ( $prefixLengthOne == '/' ) {
 723                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 724                         } else {
 725                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 726                         }
 727                         if ( $slashPos === false ) {
 728                                 $output .= substr( $urlPath, $inputOffset );
 729                                 $inputOffset = $inputLength;
 730                         } else {
 731                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 732                                 $inputOffset += $slashPos - $inputOffset;
 733                         }
 734                 }
 735
 736                 if ( $trimOutput ) {
 737                         $slashPos = strrpos( $output, '/' );
 738                         if ( $slashPos === false ) {
 739                                 $output = '';
 740                         } else {
 741                                 $output = substr( $output, 0, $slashPos );
 742                         }
 743                 }
 744         }
 745
 746         return $output;
 747 }
 748
 749 /**
 750  * Returns a regular expression of url protocols
 751  *
 752  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 753  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 754  * @return string
 755  */
 756 function wfUrlProtocols( $includeProtocolRelative = true ) {
 757         global $wgUrlProtocols;
 758
 759         // Cache return values separately based on $includeProtocolRelative
 760         static $withProtRel = null, $withoutProtRel = null;
 761         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 762         if ( !is_null( $cachedValue ) ) {
 763                 return $cachedValue;
 764         }
 765
 766         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 767         // with LocalSettings files from 1.5
 768         if ( is_array( $wgUrlProtocols ) ) {
 769                 $protocols = [];
 770                 foreach ( $wgUrlProtocols as $protocol ) {
 771                         // Filter out '//' if !$includeProtocolRelative
 772                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 773                                 $protocols[] = preg_quote( $protocol, '/' );
 774                         }
 775                 }
 776
 777                 $retval = implode( '|', $protocols );
 778         } else {
 779                 // Ignore $includeProtocolRelative in this case
 780                 // This case exists for pre-1.6 compatibility, and we can safely assume
 781                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 782                 // URLs weren't supported until 1.18
 783                 $retval = $wgUrlProtocols;
 784         }
 785
 786         // Cache return value
 787         if ( $includeProtocolRelative ) {
 788                 $withProtRel = $retval;
 789         } else {
 790                 $withoutProtRel = $retval;
 791         }
 792         return $retval;
 793 }
 794
 795 /**
 796  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 797  * you need a regex that matches all URL protocols but does not match protocol-
 798  * relative URLs
 799  * @return string
 800  */
 801 function wfUrlProtocolsWithoutProtRel() {
 802         return wfUrlProtocols( false );
 803 }
 804
 805 /**
 806  * parse_url() work-alike, but non-broken.  Differences:
 807  *
 808  * 1) Does not raise warnings on bad URLs (just returns false).
 809  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 810  *    protocol-relative URLs) correctly.
 811  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 812  *
 813  * @param string $url A URL to parse
 814  * @return string[]|bool Bits of the URL in an associative array, per PHP docs, false on failure
 815  */
 816 function wfParseUrl( $url ) {
 817         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 818
 819         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 820         // bad that the easiest way to handle them is to just prepend 'http:' and
 821         // strip the protocol out later.
 822         $wasRelative = substr( $url, 0, 2 ) == '//';
 823         if ( $wasRelative ) {
 824                 $url = "http:$url";
 825         }
 826         MediaWiki\suppressWarnings();
 827         $bits = parse_url( $url );
 828         MediaWiki\restoreWarnings();
 829         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 830         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 831         if ( !$bits || !isset( $bits['scheme'] ) ) {
 832                 return false;
 833         }
 834
 835         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 836         $bits['scheme'] = strtolower( $bits['scheme'] );
 837
 838         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 839         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 840                 $bits['delimiter'] = '://';
 841         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 842                 $bits['delimiter'] = ':';
 843                 // parse_url detects for news: and mailto: the host part of an url as path
 844                 // We have to correct this wrong detection
 845                 if ( isset( $bits['path'] ) ) {
 846                         $bits['host'] = $bits['path'];
 847                         $bits['path'] = '';
 848                 }
 849         } else {
 850                 return false;
 851         }
 852
 853         /* Provide an empty host for eg. file:/// urls (see T30627) */
 854         if ( !isset( $bits['host'] ) ) {
 855                 $bits['host'] = '';
 856
 857                 // See T47069
 858                 if ( isset( $bits['path'] ) ) {
 859                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 860                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 861                                 $bits['path'] = '/' . $bits['path'];
 862                         }
 863                 } else {
 864                         $bits['path'] = '';
 865                 }
 866         }
 867
 868         // If the URL was protocol-relative, fix scheme and delimiter
 869         if ( $wasRelative ) {
 870                 $bits['scheme'] = '';
 871                 $bits['delimiter'] = '//';
 872         }
 873         return $bits;
 874 }
 875
 876 /**
 877  * Take a URL, make sure it's expanded to fully qualified, and replace any
 878  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 879  * for more compact display and legibility for local audiences.
 880  *
 881  * @todo handle punycode domains too
 882  *
 883  * @param string $url
 884  * @return string
 885  */
 886 function wfExpandIRI( $url ) {
 887         return preg_replace_callback(
 888                 '/((?:%[89A-F][0-9A-F])+)/i',
 889                 'wfExpandIRI_callback',
 890                 wfExpandUrl( $url )
 891         );
 892 }
 893
 894 /**
 895  * Private callback for wfExpandIRI
 896  * @param array $matches
 897  * @return string
 898  */
 899 function wfExpandIRI_callback( $matches ) {
 900         return urldecode( $matches[1] );
 901 }
 902
 903 /**
 904  * Make URL indexes, appropriate for the el_index field of externallinks.
 905  *
 906  * @param string $url
 907  * @return array
 908  */
 909 function wfMakeUrlIndexes( $url ) {
 910         $bits = wfParseUrl( $url );
 911
 912         // Reverse the labels in the hostname, convert to lower case
 913         // For emails reverse domainpart only
 914         if ( $bits['scheme'] == 'mailto' ) {
 915                 $mailparts = explode( '@', $bits['host'], 2 );
 916                 if ( count( $mailparts ) === 2 ) {
 917                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 918                 } else {
 919                         // No domain specified, don't mangle it
 920                         $domainpart = '';
 921                 }
 922                 $reversedHost = $domainpart . '@' . $mailparts[0];
 923         } else {
 924                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 925         }
 926         // Add an extra dot to the end
 927         // Why? Is it in wrong place in mailto links?
 928         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 929                 $reversedHost .= '.';
 930         }
 931         // Reconstruct the pseudo-URL
 932         $prot = $bits['scheme'];
 933         $index = $prot . $bits['delimiter'] . $reversedHost;
 934         // Leave out user and password. Add the port, path, query and fragment
 935         if ( isset( $bits['port'] ) ) {
 936                 $index .= ':' . $bits['port'];
 937         }
 938         if ( isset( $bits['path'] ) ) {
 939                 $index .= $bits['path'];
 940         } else {
 941                 $index .= '/';
 942         }
 943         if ( isset( $bits['query'] ) ) {
 944                 $index .= '?' . $bits['query'];
 945         }
 946         if ( isset( $bits['fragment'] ) ) {
 947                 $index .= '#' . $bits['fragment'];
 948         }
 949
 950         if ( $prot == '' ) {
 951                 return [ "http:$index", "https:$index" ];
 952         } else {
 953                 return [ $index ];
 954         }
 955 }
 956
 957 /**
 958  * Check whether a given URL has a domain that occurs in a given set of domains
 959  * @param string $url URL
 960  * @param array $domains Array of domains (strings)
 961  * @return bool True if the host part of $url ends in one of the strings in $domains
 962  */
 963 function wfMatchesDomainList( $url, $domains ) {
 964         $bits = wfParseUrl( $url );
 965         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 966                 $host = '.' . $bits['host'];
 967                 foreach ( (array)$domains as $domain ) {
 968                         $domain = '.' . $domain;
 969                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 970                                 return true;
 971                         }
 972                 }
 973         }
 974         return false;
 975 }
 976
 977 /**
 978  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 979  * In normal operation this is a NOP.
 980  *
 981  * Controlling globals:
 982  * $wgDebugLogFile - points to the log file
 983  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 984  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 985  *
 986  * @since 1.25 support for additional context data
 987  *
 988  * @param string $text
 989  * @param string|bool $dest Destination of the message:
 990  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 991  *     - 'private': excluded from HTML output
 992  *   For backward compatibility, it can also take a boolean:
 993  *     - true: same as 'all'
 994  *     - false: same as 'private'
 995  * @param array $context Additional logging context data
 996  */
 997 function wfDebug( $text, $dest = 'all', array $context = [] ) {
 998         global $wgDebugRawPage, $wgDebugLogPrefix;
 999         global $wgDebugTimestamps, $wgRequestTime;
1000
1001         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1002                 return;
1003         }
1004
1005         $text = trim( $text );
1006
1007         if ( $wgDebugTimestamps ) {
1008                 $context['seconds_elapsed'] = sprintf(
1009                         '%6.4f',
1010                         microtime( true ) - $wgRequestTime
1011                 );
1012                 $context['memory_used'] = sprintf(
1013                         '%5.1fM',
1014                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1015                 );
1016         }
1017
1018         if ( $wgDebugLogPrefix !== '' ) {
1019                 $context['prefix'] = $wgDebugLogPrefix;
1020         }
1021         $context['private'] = ( $dest === false || $dest === 'private' );
1022
1023         $logger = LoggerFactory::getInstance( 'wfDebug' );
1024         $logger->debug( $text, $context );
1025 }
1026
1027 /**
1028  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1029  * @return bool
1030  */
1031 function wfIsDebugRawPage() {
1032         static $cache;
1033         if ( $cache !== null ) {
1034                 return $cache;
1035         }
1036         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1037         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1038                 || (
1039                         isset( $_SERVER['SCRIPT_NAME'] )
1040                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1041                 )
1042         ) {
1043                 $cache = true;
1044         } else {
1045                 $cache = false;
1046         }
1047         return $cache;
1048 }
1049
1050 /**
1051  * Send a line giving PHP memory usage.
1052  *
1053  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1054  */
1055 function wfDebugMem( $exact = false ) {
1056         $mem = memory_get_usage();
1057         if ( !$exact ) {
1058                 $mem = floor( $mem / 1024 ) . ' KiB';
1059         } else {
1060                 $mem .= ' B';
1061         }
1062         wfDebug( "Memory usage: $mem\n" );
1063 }
1064
1065 /**
1066  * Send a line to a supplementary debug log file, if configured, or main debug
1067  * log if not.
1068  *
1069  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1070  * a string filename or an associative array mapping 'destination' to the
1071  * desired filename. The associative array may also contain a 'sample' key
1072  * with an integer value, specifying a sampling factor. Sampled log events
1073  * will be emitted with a 1 in N random chance.
1074  *
1075  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1076  * @since 1.25 support for additional context data
1077  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1078  *
1079  * @param string $logGroup
1080  * @param string $text
1081  * @param string|bool $dest Destination of the message:
1082  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1083  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1084  *       discarded otherwise
1085  *   For backward compatibility, it can also take a boolean:
1086  *     - true: same as 'all'
1087  *     - false: same as 'private'
1088  * @param array $context Additional logging context data
1089  */
1090 function wfDebugLog(
1091         $logGroup, $text, $dest = 'all', array $context = []
1092 ) {
1093         $text = trim( $text );
1094
1095         $logger = LoggerFactory::getInstance( $logGroup );
1096         $context['private'] = ( $dest === false || $dest === 'private' );
1097         $logger->info( $text, $context );
1098 }
1099
1100 /**
1101  * Log for database errors
1102  *
1103  * @since 1.25 support for additional context data
1104  *
1105  * @param string $text Database error message.
1106  * @param array $context Additional logging context data
1107  */
1108 function wfLogDBError( $text, array $context = [] ) {
1109         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1110         $logger->error( trim( $text ), $context );
1111 }
1112
1113 /**
1114  * Throws a warning that $function is deprecated
1115  *
1116  * @param string $function
1117  * @param string|bool $version Version of MediaWiki that the function
1118  *    was deprecated in (Added in 1.19).
1119  * @param string|bool $component Added in 1.19.
1120  * @param int $callerOffset How far up the call stack is the original
1121  *    caller. 2 = function that called the function that called
1122  *    wfDeprecated (Added in 1.20)
1123  *
1124  * @return null
1125  */
1126 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1127         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1128 }
1129
1130 /**
1131  * Send a warning either to the debug log or in a PHP error depending on
1132  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1133  *
1134  * @param string $msg Message to send
1135  * @param int $callerOffset Number of items to go back in the backtrace to
1136  *        find the correct caller (1 = function calling wfWarn, ...)
1137  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1138  *        only used when $wgDevelopmentWarnings is true
1139  */
1140 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1141         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1142 }
1143
1144 /**
1145  * Send a warning as a PHP error and the debug log. This is intended for logging
1146  * warnings in production. For logging development warnings, use WfWarn instead.
1147  *
1148  * @param string $msg Message to send
1149  * @param int $callerOffset Number of items to go back in the backtrace to
1150  *        find the correct caller (1 = function calling wfLogWarning, ...)
1151  * @param int $level PHP error level; defaults to E_USER_WARNING
1152  */
1153 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1154         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1155 }
1156
1157 /**
1158  * Log to a file without getting "file size exceeded" signals.
1159  *
1160  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1161  * send lines to the specified port, prefixed by the specified prefix and a space.
1162  * @since 1.25 support for additional context data
1163  *
1164  * @param string $text
1165  * @param string $file Filename
1166  * @param array $context Additional logging context data
1167  * @throws MWException
1168  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1169  */
1170 function wfErrorLog( $text, $file, array $context = [] ) {
1171         wfDeprecated( __METHOD__, '1.25' );
1172         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1173         $context['destination'] = $file;
1174         $logger->info( trim( $text ), $context );
1175 }
1176
1177 /**
1178  * @todo document
1179  */
1180 function wfLogProfilingData() {
1181         global $wgDebugLogGroups, $wgDebugRawPage;
1182
1183         $context = RequestContext::getMain();
1184         $request = $context->getRequest();
1185
1186         $profiler = Profiler::instance();
1187         $profiler->setContext( $context );
1188         $profiler->logData();
1189
1190         $config = $context->getConfig();
1191         if ( $config->get( 'StatsdServer' ) ) {
1192                 try {
1193                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1194                         $statsdHost = $statsdServer[0];
1195                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1196                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1197                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1198                         $statsdClient->setSamplingRates( $config->get( 'StatsdSamplingRates' ) );
1199                         $statsdClient->send( $context->getStats()->getBuffer() );
1200                 } catch ( Exception $ex ) {
1201                         MWExceptionHandler::logException( $ex );
1202                 }
1203         }
1204
1205         # Profiling must actually be enabled...
1206         if ( $profiler instanceof ProfilerStub ) {
1207                 return;
1208         }
1209
1210         if ( isset( $wgDebugLogGroups['profileoutput'] )
1211                 && $wgDebugLogGroups['profileoutput'] === false
1212         ) {
1213                 // Explicitly disabled
1214                 return;
1215         }
1216         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1217                 return;
1218         }
1219
1220         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1221         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1222                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1223         }
1224         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1225                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1226         }
1227         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1228                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1229         }
1230         if ( isset( $ctx['forwarded_for'] ) ||
1231                 isset( $ctx['client_ip'] ) ||
1232                 isset( $ctx['from'] ) ) {
1233                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1234         }
1235
1236         // Don't load $wgUser at this late stage just for statistics purposes
1237         // @todo FIXME: We can detect some anons even if it is not loaded.
1238         // See User::getId()
1239         $user = $context->getUser();
1240         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1241
1242         // Command line script uses a FauxRequest object which does not have
1243         // any knowledge about an URL and throw an exception instead.
1244         try {
1245                 $ctx['url'] = urldecode( $request->getRequestURL() );
1246         } catch ( Exception $ignored ) {
1247                 // no-op
1248         }
1249
1250         $ctx['output'] = $profiler->getOutput();
1251
1252         $log = LoggerFactory::getInstance( 'profileoutput' );
1253         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1254 }
1255
1256 /**
1257  * Increment a statistics counter
1258  *
1259  * @param string $key
1260  * @param int $count
1261  * @return void
1262  */
1263 function wfIncrStats( $key, $count = 1 ) {
1264         $stats = RequestContext::getMain()->getStats();
1265         $stats->updateCount( $key, $count );
1266 }
1267
1268 /**
1269  * Check whether the wiki is in read-only mode.
1270  *
1271  * @return bool
1272  */
1273 function wfReadOnly() {
1274         return wfReadOnlyReason() !== false;
1275 }
1276
1277 /**
1278  * Check if the site is in read-only mode and return the message if so
1279  *
1280  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1281  * for replica DB lag. This may result in DB connection being made.
1282  *
1283  * @return string|bool String when in read-only mode; false otherwise
1284  */
1285 function wfReadOnlyReason() {
1286         $readOnly = wfConfiguredReadOnlyReason();
1287         if ( $readOnly !== false ) {
1288                 return $readOnly;
1289         }
1290
1291         static $lbReadOnly = null;
1292         if ( $lbReadOnly === null ) {
1293                 // Callers use this method to be aware that data presented to a user
1294                 // may be very stale and thus allowing submissions can be problematic.
1295                 $lbReadOnly = wfGetLB()->getReadOnlyReason();
1296         }
1297
1298         return $lbReadOnly;
1299 }
1300
1301 /**
1302  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1303  *
1304  * @return string|bool String when in read-only mode; false otherwise
1305  * @since 1.27
1306  */
1307 function wfConfiguredReadOnlyReason() {
1308         global $wgReadOnly, $wgReadOnlyFile;
1309
1310         if ( $wgReadOnly === null ) {
1311                 // Set $wgReadOnly for faster access next time
1312                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1313                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1314                 } else {
1315                         $wgReadOnly = false;
1316                 }
1317         }
1318
1319         return $wgReadOnly;
1320 }
1321
1322 /**
1323  * Return a Language object from $langcode
1324  *
1325  * @param Language|string|bool $langcode Either:
1326  *                  - a Language object
1327  *                  - code of the language to get the message for, if it is
1328  *                    a valid code create a language for that language, if
1329  *                    it is a string but not a valid code then make a basic
1330  *                    language object
1331  *                  - a boolean: if it's false then use the global object for
1332  *                    the current user's language (as a fallback for the old parameter
1333  *                    functionality), or if it is true then use global object
1334  *                    for the wiki's content language.
1335  * @return Language
1336  */
1337 function wfGetLangObj( $langcode = false ) {
1338         # Identify which language to get or create a language object for.
1339         # Using is_object here due to Stub objects.
1340         if ( is_object( $langcode ) ) {
1341                 # Great, we already have the object (hopefully)!
1342                 return $langcode;
1343         }
1344
1345         global $wgContLang, $wgLanguageCode;
1346         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1347                 # $langcode is the language code of the wikis content language object.
1348                 # or it is a boolean and value is true
1349                 return $wgContLang;
1350         }
1351
1352         global $wgLang;
1353         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1354                 # $langcode is the language code of user language object.
1355                 # or it was a boolean and value is false
1356                 return $wgLang;
1357         }
1358
1359         $validCodes = array_keys( Language::fetchLanguageNames() );
1360         if ( in_array( $langcode, $validCodes ) ) {
1361                 # $langcode corresponds to a valid language.
1362                 return Language::factory( $langcode );
1363         }
1364
1365         # $langcode is a string, but not a valid language code; use content language.
1366         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1367         return $wgContLang;
1368 }
1369
1370 /**
1371  * This is the function for getting translated interface messages.
1372  *
1373  * @see Message class for documentation how to use them.
1374  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1375  *
1376  * This function replaces all old wfMsg* functions.
1377  *
1378  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1379  * @param mixed $params,... Normal message parameters
1380  * @return Message
1381  *
1382  * @since 1.17
1383  *
1384  * @see Message::__construct
1385  */
1386 function wfMessage( $key /*...*/ ) {
1387         $params = func_get_args();
1388         array_shift( $params );
1389         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1390                 $params = $params[0];
1391         }
1392         return new Message( $key, $params );
1393 }
1394
1395 /**
1396  * This function accepts multiple message keys and returns a message instance
1397  * for the first message which is non-empty. If all messages are empty then an
1398  * instance of the first message key is returned.
1399  *
1400  * @param string|string[] $keys,... Message keys
1401  * @return Message
1402  *
1403  * @since 1.18
1404  *
1405  * @see Message::newFallbackSequence
1406  */
1407 function wfMessageFallback( /*...*/ ) {
1408         $args = func_get_args();
1409         return call_user_func_array( 'Message::newFallbackSequence', $args );
1410 }
1411
1412 /**
1413  * Replace message parameter keys on the given formatted output.
1414  *
1415  * @param string $message
1416  * @param array $args
1417  * @return string
1418  * @private
1419  */
1420 function wfMsgReplaceArgs( $message, $args ) {
1421         # Fix windows line-endings
1422         # Some messages are split with explode("\n", $msg)
1423         $message = str_replace( "\r", '', $message );
1424
1425         // Replace arguments
1426         if ( is_array( $args ) && $args ) {
1427                 if ( is_array( $args[0] ) ) {
1428                         $args = array_values( $args[0] );
1429                 }
1430                 $replacementKeys = [];
1431                 foreach ( $args as $n => $param ) {
1432                         $replacementKeys['$' . ( $n + 1 )] = $param;
1433                 }
1434                 $message = strtr( $message, $replacementKeys );
1435         }
1436
1437         return $message;
1438 }
1439
1440 /**
1441  * Fetch server name for use in error reporting etc.
1442  * Use real server name if available, so we know which machine
1443  * in a server farm generated the current page.
1444  *
1445  * @return string
1446  */
1447 function wfHostname() {
1448         static $host;
1449         if ( is_null( $host ) ) {
1450
1451                 # Hostname overriding
1452                 global $wgOverrideHostname;
1453                 if ( $wgOverrideHostname !== false ) {
1454                         # Set static and skip any detection
1455                         $host = $wgOverrideHostname;
1456                         return $host;
1457                 }
1458
1459                 if ( function_exists( 'posix_uname' ) ) {
1460                         // This function not present on Windows
1461                         $uname = posix_uname();
1462                 } else {
1463                         $uname = false;
1464                 }
1465                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1466                         $host = $uname['nodename'];
1467                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1468                         # Windows computer name
1469                         $host = getenv( 'COMPUTERNAME' );
1470                 } else {
1471                         # This may be a virtual server.
1472                         $host = $_SERVER['SERVER_NAME'];
1473                 }
1474         }
1475         return $host;
1476 }
1477
1478 /**
1479  * Returns a script tag that stores the amount of time it took MediaWiki to
1480  * handle the request in milliseconds as 'wgBackendResponseTime'.
1481  *
1482  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1483  * hostname of the server handling the request.
1484  *
1485  * @return string
1486  */
1487 function wfReportTime() {
1488         global $wgRequestTime, $wgShowHostnames;
1489
1490         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1491         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1492         if ( $wgShowHostnames ) {
1493                 $reportVars['wgHostname'] = wfHostname();
1494         }
1495         return Skin::makeVariablesScript( $reportVars );
1496 }
1497
1498 /**
1499  * Safety wrapper for debug_backtrace().
1500  *
1501  * Will return an empty array if debug_backtrace is disabled, otherwise
1502  * the output from debug_backtrace() (trimmed).
1503  *
1504  * @param int $limit This parameter can be used to limit the number of stack frames returned
1505  *
1506  * @return array Array of backtrace information
1507  */
1508 function wfDebugBacktrace( $limit = 0 ) {
1509         static $disabled = null;
1510
1511         if ( is_null( $disabled ) ) {
1512                 $disabled = !function_exists( 'debug_backtrace' );
1513                 if ( $disabled ) {
1514                         wfDebug( "debug_backtrace() is disabled\n" );
1515                 }
1516         }
1517         if ( $disabled ) {
1518                 return [];
1519         }
1520
1521         if ( $limit ) {
1522                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1523         } else {
1524                 return array_slice( debug_backtrace(), 1 );
1525         }
1526 }
1527
1528 /**
1529  * Get a debug backtrace as a string
1530  *
1531  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1532  *   Defaults to $wgCommandLineMode if unset.
1533  * @return string
1534  * @since 1.25 Supports $raw parameter.
1535  */
1536 function wfBacktrace( $raw = null ) {
1537         global $wgCommandLineMode;
1538
1539         if ( $raw === null ) {
1540                 $raw = $wgCommandLineMode;
1541         }
1542
1543         if ( $raw ) {
1544                 $frameFormat = "%s line %s calls %s()\n";
1545                 $traceFormat = "%s";
1546         } else {
1547                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1548                 $traceFormat = "<ul>\n%s</ul>\n";
1549         }
1550
1551         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1552                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1553                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1554                 $call = $frame['function'];
1555                 if ( !empty( $frame['class'] ) ) {
1556                         $call = $frame['class'] . $frame['type'] . $call;
1557                 }
1558                 return sprintf( $frameFormat, $file, $line, $call );
1559         }, wfDebugBacktrace() );
1560
1561         return sprintf( $traceFormat, implode( '', $frames ) );
1562 }
1563
1564 /**
1565  * Get the name of the function which called this function
1566  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1567  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1568  * wfGetCaller( 3 ) is the parent of that.
1569  *
1570  * @param int $level
1571  * @return string
1572  */
1573 function wfGetCaller( $level = 2 ) {
1574         $backtrace = wfDebugBacktrace( $level + 1 );
1575         if ( isset( $backtrace[$level] ) ) {
1576                 return wfFormatStackFrame( $backtrace[$level] );
1577         } else {
1578                 return 'unknown';
1579         }
1580 }
1581
1582 /**
1583  * Return a string consisting of callers in the stack. Useful sometimes
1584  * for profiling specific points.
1585  *
1586  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1587  * @return string
1588  */
1589 function wfGetAllCallers( $limit = 3 ) {
1590         $trace = array_reverse( wfDebugBacktrace() );
1591         if ( !$limit || $limit > count( $trace ) - 1 ) {
1592                 $limit = count( $trace ) - 1;
1593         }
1594         $trace = array_slice( $trace, -$limit - 1, $limit );
1595         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1596 }
1597
1598 /**
1599  * Return a string representation of frame
1600  *
1601  * @param array $frame
1602  * @return string
1603  */
1604 function wfFormatStackFrame( $frame ) {
1605         if ( !isset( $frame['function'] ) ) {
1606                 return 'NO_FUNCTION_GIVEN';
1607         }
1608         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1609                 $frame['class'] . $frame['type'] . $frame['function'] :
1610                 $frame['function'];
1611 }
1612
1613 /* Some generic result counters, pulled out of SearchEngine */
1614
1615 /**
1616  * @todo document
1617  *
1618  * @param int $offset
1619  * @param int $limit
1620  * @return string
1621  */
1622 function wfShowingResults( $offset, $limit ) {
1623         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1624 }
1625
1626 /**
1627  * @todo document
1628  * @todo FIXME: We may want to blacklist some broken browsers
1629  *
1630  * @param bool $force
1631  * @return bool Whereas client accept gzip compression
1632  */
1633 function wfClientAcceptsGzip( $force = false ) {
1634         static $result = null;
1635         if ( $result === null || $force ) {
1636                 $result = false;
1637                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1638                         # @todo FIXME: We may want to blacklist some broken browsers
1639                         $m = [];
1640                         if ( preg_match(
1641                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1642                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1643                                         $m
1644                                 )
1645                         ) {
1646                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1647                                         $result = false;
1648                                         return $result;
1649                                 }
1650                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1651                                 $result = true;
1652                         }
1653                 }
1654         }
1655         return $result;
1656 }
1657
1658 /**
1659  * @deprecated since 1.28, use Parser::escapeWikitext() directly
1660  *
1661  * Escapes the given text so that it may be output using addWikiText()
1662  * without any linking, formatting, etc. making its way through. This
1663  * is achieved by substituting certain characters with HTML entities.
1664  * As required by the callers, "<nowiki>" is not used.
1665  *
1666  * @param string $text Text to be escaped
1667  * @return string
1668  */
1669 function wfEscapeWikiText( $text ) {
1670         global $wgParser;
1671         return $wgParser->escapeWikitext( $text );
1672 }
1673
1674 /**
1675  * Sets dest to source and returns the original value of dest
1676  * If source is NULL, it just returns the value, it doesn't set the variable
1677  * If force is true, it will set the value even if source is NULL
1678  *
1679  * @param mixed $dest
1680  * @param mixed $source
1681  * @param bool $force
1682  * @return mixed
1683  */
1684 function wfSetVar( &$dest, $source, $force = false ) {
1685         $temp = $dest;
1686         if ( !is_null( $source ) || $force ) {
1687                 $dest = $source;
1688         }
1689         return $temp;
1690 }
1691
1692 /**
1693  * As for wfSetVar except setting a bit
1694  *
1695  * @param int $dest
1696  * @param int $bit
1697  * @param bool $state
1698  *
1699  * @return bool
1700  */
1701 function wfSetBit( &$dest, $bit, $state = true ) {
1702         $temp = (bool)( $dest & $bit );
1703         if ( !is_null( $state ) ) {
1704                 if ( $state ) {
1705                         $dest |= $bit;
1706                 } else {
1707                         $dest &= ~$bit;
1708                 }
1709         }
1710         return $temp;
1711 }
1712
1713 /**
1714  * A wrapper around the PHP function var_export().
1715  * Either print it or add it to the regular output ($wgOut).
1716  *
1717  * @param mixed $var A PHP variable to dump.
1718  */
1719 function wfVarDump( $var ) {
1720         global $wgOut;
1721         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1722         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1723                 print $s;
1724         } else {
1725                 $wgOut->addHTML( $s );
1726         }
1727 }
1728
1729 /**
1730  * Provide a simple HTTP error.
1731  *
1732  * @param int|string $code
1733  * @param string $label
1734  * @param string $desc
1735  */
1736 function wfHttpError( $code, $label, $desc ) {
1737         global $wgOut;
1738         HttpStatus::header( $code );
1739         if ( $wgOut ) {
1740                 $wgOut->disable();
1741                 $wgOut->sendCacheControl();
1742         }
1743
1744         header( 'Content-type: text/html; charset=utf-8' );
1745         print '<!DOCTYPE html>' .
1746                 '<html><head><title>' .
1747                 htmlspecialchars( $label ) .
1748                 '</title></head><body><h1>' .
1749                 htmlspecialchars( $label ) .
1750                 '</h1><p>' .
1751                 nl2br( htmlspecialchars( $desc ) ) .
1752                 "</p></body></html>\n";
1753 }
1754
1755 /**
1756  * Clear away any user-level output buffers, discarding contents.
1757  *
1758  * Suitable for 'starting afresh', for instance when streaming
1759  * relatively large amounts of data without buffering, or wanting to
1760  * output image files without ob_gzhandler's compression.
1761  *
1762  * The optional $resetGzipEncoding parameter controls suppression of
1763  * the Content-Encoding header sent by ob_gzhandler; by default it
1764  * is left. See comments for wfClearOutputBuffers() for why it would
1765  * be used.
1766  *
1767  * Note that some PHP configuration options may add output buffer
1768  * layers which cannot be removed; these are left in place.
1769  *
1770  * @param bool $resetGzipEncoding
1771  */
1772 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1773         if ( $resetGzipEncoding ) {
1774                 // Suppress Content-Encoding and Content-Length
1775                 // headers from 1.10+s wfOutputHandler
1776                 global $wgDisableOutputCompression;
1777                 $wgDisableOutputCompression = true;
1778         }
1779         while ( $status = ob_get_status() ) {
1780                 if ( isset( $status['flags'] ) ) {
1781                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1782                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1783                 } elseif ( isset( $status['del'] ) ) {
1784                         $deleteable = $status['del'];
1785                 } else {
1786                         // Guess that any PHP-internal setting can't be removed.
1787                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1788                 }
1789                 if ( !$deleteable ) {
1790                         // Give up, and hope the result doesn't break
1791                         // output behavior.
1792                         break;
1793                 }
1794                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1795                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1796                         break;
1797                 }
1798                 if ( !ob_end_clean() ) {
1799                         // Could not remove output buffer handler; abort now
1800                         // to avoid getting in some kind of infinite loop.
1801                         break;
1802                 }
1803                 if ( $resetGzipEncoding ) {
1804                         if ( $status['name'] == 'ob_gzhandler' ) {
1805                                 // Reset the 'Content-Encoding' field set by this handler
1806                                 // so we can start fresh.
1807                                 header_remove( 'Content-Encoding' );
1808                                 break;
1809                         }
1810                 }
1811         }
1812 }
1813
1814 /**
1815  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1816  *
1817  * Clear away output buffers, but keep the Content-Encoding header
1818  * produced by ob_gzhandler, if any.
1819  *
1820  * This should be used for HTTP 304 responses, where you need to
1821  * preserve the Content-Encoding header of the real result, but
1822  * also need to suppress the output of ob_gzhandler to keep to spec
1823  * and avoid breaking Firefox in rare cases where the headers and
1824  * body are broken over two packets.
1825  */
1826 function wfClearOutputBuffers() {
1827         wfResetOutputBuffers( false );
1828 }
1829
1830 /**
1831  * Converts an Accept-* header into an array mapping string values to quality
1832  * factors
1833  *
1834  * @param string $accept
1835  * @param string $def Default
1836  * @return float[] Associative array of string => float pairs
1837  */
1838 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1839         # No arg means accept anything (per HTTP spec)
1840         if ( !$accept ) {
1841                 return [ $def => 1.0 ];
1842         }
1843
1844         $prefs = [];
1845
1846         $parts = explode( ',', $accept );
1847
1848         foreach ( $parts as $part ) {
1849                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1850                 $values = explode( ';', trim( $part ) );
1851                 $match = [];
1852                 if ( count( $values ) == 1 ) {
1853                         $prefs[$values[0]] = 1.0;
1854                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1855                         $prefs[$values[0]] = floatval( $match[1] );
1856                 }
1857         }
1858
1859         return $prefs;
1860 }
1861
1862 /**
1863  * Checks if a given MIME type matches any of the keys in the given
1864  * array. Basic wildcards are accepted in the array keys.
1865  *
1866  * Returns the matching MIME type (or wildcard) if a match, otherwise
1867  * NULL if no match.
1868  *
1869  * @param string $type
1870  * @param array $avail
1871  * @return string
1872  * @private
1873  */
1874 function mimeTypeMatch( $type, $avail ) {
1875         if ( array_key_exists( $type, $avail ) ) {
1876                 return $type;
1877         } else {
1878                 $mainType = explode( '/', $type )[0];
1879                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1880                         return "$mainType/*";
1881                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1882                         return '*/*';
1883                 } else {
1884                         return null;
1885                 }
1886         }
1887 }
1888
1889 /**
1890  * Returns the 'best' match between a client's requested internet media types
1891  * and the server's list of available types. Each list should be an associative
1892  * array of type to preference (preference is a float between 0.0 and 1.0).
1893  * Wildcards in the types are acceptable.
1894  *
1895  * @param array $cprefs Client's acceptable type list
1896  * @param array $sprefs Server's offered types
1897  * @return string
1898  *
1899  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1900  * XXX: generalize to negotiate other stuff
1901  */
1902 function wfNegotiateType( $cprefs, $sprefs ) {
1903         $combine = [];
1904
1905         foreach ( array_keys( $sprefs ) as $type ) {
1906                 $subType = explode( '/', $type )[1];
1907                 if ( $subType != '*' ) {
1908                         $ckey = mimeTypeMatch( $type, $cprefs );
1909                         if ( $ckey ) {
1910                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1911                         }
1912                 }
1913         }
1914
1915         foreach ( array_keys( $cprefs ) as $type ) {
1916                 $subType = explode( '/', $type )[1];
1917                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1918                         $skey = mimeTypeMatch( $type, $sprefs );
1919                         if ( $skey ) {
1920                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1921                         }
1922                 }
1923         }
1924
1925         $bestq = 0;
1926         $besttype = null;
1927
1928         foreach ( array_keys( $combine ) as $type ) {
1929                 if ( $combine[$type] > $bestq ) {
1930                         $besttype = $type;
1931                         $bestq = $combine[$type];
1932                 }
1933         }
1934
1935         return $besttype;
1936 }
1937
1938 /**
1939  * Reference-counted warning suppression
1940  *
1941  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
1942  * @param bool $end
1943  */
1944 function wfSuppressWarnings( $end = false ) {
1945         MediaWiki\suppressWarnings( $end );
1946 }
1947
1948 /**
1949  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
1950  * Restore error level to previous value
1951  */
1952 function wfRestoreWarnings() {
1953         MediaWiki\suppressWarnings( true );
1954 }
1955
1956 # Autodetect, convert and provide timestamps of various types
1957
1958 require_once __DIR__ . '/libs/time/defines.php';
1959
1960 /**
1961  * Get a timestamp string in one of various formats
1962  *
1963  * @param mixed $outputtype A timestamp in one of the supported formats, the
1964  *   function will autodetect which format is supplied and act accordingly.
1965  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
1966  * @return string|bool String / false The same date in the format specified in $outputtype or false
1967  */
1968 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
1969         $ret = MWTimestamp::convert( $outputtype, $ts );
1970         if ( $ret === false ) {
1971                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
1972         }
1973         return $ret;
1974 }
1975
1976 /**
1977  * Return a formatted timestamp, or null if input is null.
1978  * For dealing with nullable timestamp columns in the database.
1979  *
1980  * @param int $outputtype
1981  * @param string $ts
1982  * @return string
1983  */
1984 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
1985         if ( is_null( $ts ) ) {
1986                 return null;
1987         } else {
1988                 return wfTimestamp( $outputtype, $ts );
1989         }
1990 }
1991
1992 /**
1993  * Convenience function; returns MediaWiki timestamp for the present time.
1994  *
1995  * @return string
1996  */
1997 function wfTimestampNow() {
1998         # return NOW
1999         return MWTimestamp::now( TS_MW );
2000 }
2001
2002 /**
2003  * Check if the operating system is Windows
2004  *
2005  * @return bool True if it's Windows, false otherwise.
2006  */
2007 function wfIsWindows() {
2008         static $isWindows = null;
2009         if ( $isWindows === null ) {
2010                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2011         }
2012         return $isWindows;
2013 }
2014
2015 /**
2016  * Check if we are running under HHVM
2017  *
2018  * @return bool
2019  */
2020 function wfIsHHVM() {
2021         return defined( 'HHVM_VERSION' );
2022 }
2023
2024 /**
2025  * Tries to get the system directory for temporary files. First
2026  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2027  * environment variables are then checked in sequence, then
2028  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2029  *
2030  * NOTE: When possible, use instead the tmpfile() function to create
2031  * temporary files to avoid race conditions on file creation, etc.
2032  *
2033  * @return string
2034  */
2035 function wfTempDir() {
2036         global $wgTmpDirectory;
2037
2038         if ( $wgTmpDirectory !== false ) {
2039                 return $wgTmpDirectory;
2040         }
2041
2042         return TempFSFile::getUsableTempDirectory();
2043 }
2044
2045 /**
2046  * Make directory, and make all parent directories if they don't exist
2047  *
2048  * @param string $dir Full path to directory to create
2049  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2050  * @param string $caller Optional caller param for debugging.
2051  * @throws MWException
2052  * @return bool
2053  */
2054 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2055         global $wgDirectoryMode;
2056
2057         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2058                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2059         }
2060
2061         if ( !is_null( $caller ) ) {
2062                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2063         }
2064
2065         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2066                 return true;
2067         }
2068
2069         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
2070
2071         if ( is_null( $mode ) ) {
2072                 $mode = $wgDirectoryMode;
2073         }
2074
2075         // Turn off the normal warning, we're doing our own below
2076         MediaWiki\suppressWarnings();
2077         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2078         MediaWiki\restoreWarnings();
2079
2080         if ( !$ok ) {
2081                 // directory may have been created on another request since we last checked
2082                 if ( is_dir( $dir ) ) {
2083                         return true;
2084                 }
2085
2086                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2087                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2088         }
2089         return $ok;
2090 }
2091
2092 /**
2093  * Remove a directory and all its content.
2094  * Does not hide error.
2095  * @param string $dir
2096  */
2097 function wfRecursiveRemoveDir( $dir ) {
2098         wfDebug( __FUNCTION__ . "( $dir )\n" );
2099         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2100         if ( is_dir( $dir ) ) {
2101                 $objects = scandir( $dir );
2102                 foreach ( $objects as $object ) {
2103                         if ( $object != "." && $object != ".." ) {
2104                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2105                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2106                                 } else {
2107                                         unlink( $dir . '/' . $object );
2108                                 }
2109                         }
2110                 }
2111                 reset( $objects );
2112                 rmdir( $dir );
2113         }
2114 }
2115
2116 /**
2117  * @param int $nr The number to format
2118  * @param int $acc The number of digits after the decimal point, default 2
2119  * @param bool $round Whether or not to round the value, default true
2120  * @return string
2121  */
2122 function wfPercent( $nr, $acc = 2, $round = true ) {
2123         $ret = sprintf( "%.${acc}f", $nr );
2124         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2125 }
2126
2127 /**
2128  * Safety wrapper around ini_get() for boolean settings.
2129  * The values returned from ini_get() are pre-normalized for settings
2130  * set via php.ini or php_flag/php_admin_flag... but *not*
2131  * for those set via php_value/php_admin_value.
2132  *
2133  * It's fairly common for people to use php_value instead of php_flag,
2134  * which can leave you with an 'off' setting giving a false positive
2135  * for code that just takes the ini_get() return value as a boolean.
2136  *
2137  * To make things extra interesting, setting via php_value accepts
2138  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2139  * Unrecognized values go false... again opposite PHP's own coercion
2140  * from string to bool.
2141  *
2142  * Luckily, 'properly' set settings will always come back as '0' or '1',
2143  * so we only have to worry about them and the 'improper' settings.
2144  *
2145  * I frickin' hate PHP... :P
2146  *
2147  * @param string $setting
2148  * @return bool
2149  */
2150 function wfIniGetBool( $setting ) {
2151         $val = strtolower( ini_get( $setting ) );
2152         // 'on' and 'true' can't have whitespace around them, but '1' can.
2153         return $val == 'on'
2154                 || $val == 'true'
2155                 || $val == 'yes'
2156                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2157 }
2158
2159 /**
2160  * Windows-compatible version of escapeshellarg()
2161  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2162  * function puts single quotes in regardless of OS.
2163  *
2164  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2165  * earlier distro releases of PHP)
2166  *
2167  * @param string ... strings to escape and glue together, or a single array of strings parameter
2168  * @return string
2169  */
2170 function wfEscapeShellArg( /*...*/ ) {
2171         wfInitShellLocale();
2172
2173         $args = func_get_args();
2174         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2175                 // If only one argument has been passed, and that argument is an array,
2176                 // treat it as a list of arguments
2177                 $args = reset( $args );
2178         }
2179
2180         $first = true;
2181         $retVal = '';
2182         foreach ( $args as $arg ) {
2183                 if ( !$first ) {
2184                         $retVal .= ' ';
2185                 } else {
2186                         $first = false;
2187                 }
2188
2189                 if ( wfIsWindows() ) {
2190                         // Escaping for an MSVC-style command line parser and CMD.EXE
2191                         // @codingStandardsIgnoreStart For long URLs
2192                         // Refs:
2193                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2194                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2195                         //  * T15518
2196                         //  * CR r63214
2197                         // Double the backslashes before any double quotes. Escape the double quotes.
2198                         // @codingStandardsIgnoreEnd
2199                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2200                         $arg = '';
2201                         $iteration = 0;
2202                         foreach ( $tokens as $token ) {
2203                                 if ( $iteration % 2 == 1 ) {
2204                                         // Delimiter, a double quote preceded by zero or more slashes
2205                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2206                                 } elseif ( $iteration % 4 == 2 ) {
2207                                         // ^ in $token will be outside quotes, need to be escaped
2208                                         $arg .= str_replace( '^', '^^', $token );
2209                                 } else { // $iteration % 4 == 0
2210                                         // ^ in $token will appear inside double quotes, so leave as is
2211                                         $arg .= $token;
2212                                 }
2213                                 $iteration++;
2214                         }
2215                         // Double the backslashes before the end of the string, because
2216                         // we will soon add a quote
2217                         $m = [];
2218                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2219                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2220                         }
2221
2222                         // Add surrounding quotes
2223                         $retVal .= '"' . $arg . '"';
2224                 } else {
2225                         $retVal .= escapeshellarg( $arg );
2226                 }
2227         }
2228         return $retVal;
2229 }
2230
2231 /**
2232  * Check if wfShellExec() is effectively disabled via php.ini config
2233  *
2234  * @return bool|string False or 'disabled'
2235  * @since 1.22
2236  */
2237 function wfShellExecDisabled() {
2238         static $disabled = null;
2239         if ( is_null( $disabled ) ) {
2240                 if ( !function_exists( 'proc_open' ) ) {
2241                         wfDebug( "proc_open() is disabled\n" );
2242                         $disabled = 'disabled';
2243                 } else {
2244                         $disabled = false;
2245                 }
2246         }
2247         return $disabled;
2248 }
2249
2250 /**
2251  * Execute a shell command, with time and memory limits mirrored from the PHP
2252  * configuration if supported.
2253  *
2254  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2255  *   or an array of unescaped arguments, in which case each value will be escaped
2256  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2257  * @param null|mixed &$retval Optional, will receive the program's exit code.
2258  *   (non-zero is usually failure). If there is an error from
2259  *   read, select, or proc_open(), this will be set to -1.
2260  * @param array $environ Optional environment variables which should be
2261  *   added to the executed command environment.
2262  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2263  *   this overwrites the global wgMaxShell* limits.
2264  * @param array $options Array of options:
2265  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2266  *     including errors from limit.sh
2267  *   - profileMethod: By default this function will profile based on the calling
2268  *     method. Set this to a string for an alternative method to profile from
2269  *
2270  * @return string Collected stdout as a string
2271  */
2272 function wfShellExec( $cmd, &$retval = null, $environ = [],
2273         $limits = [], $options = []
2274 ) {
2275         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2276                 $wgMaxShellWallClockTime, $wgShellCgroup;
2277
2278         $disabled = wfShellExecDisabled();
2279         if ( $disabled ) {
2280                 $retval = 1;
2281                 return 'Unable to run external programs, proc_open() is disabled.';
2282         }
2283
2284         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2285         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2286
2287         wfInitShellLocale();
2288
2289         $envcmd = '';
2290         foreach ( $environ as $k => $v ) {
2291                 if ( wfIsWindows() ) {
2292                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2293                          * appear in the environment variable, so we must use carat escaping as documented in
2294                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2295                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2296                          * are listed there but doesn't appear to need it.
2297                          */
2298                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2299                 } else {
2300                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2301                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2302                          */
2303                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2304                 }
2305         }
2306         if ( is_array( $cmd ) ) {
2307                 $cmd = wfEscapeShellArg( $cmd );
2308         }
2309
2310         $cmd = $envcmd . $cmd;
2311
2312         $useLogPipe = false;
2313         if ( is_executable( '/bin/bash' ) ) {
2314                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2315                 if ( isset( $limits['walltime'] ) ) {
2316                         $wallTime = intval( $limits['walltime'] );
2317                 } elseif ( isset( $limits['time'] ) ) {
2318                         $wallTime = $time;
2319                 } else {
2320                         $wallTime = intval( $wgMaxShellWallClockTime );
2321                 }
2322                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2323                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2324
2325                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2326                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2327                                 escapeshellarg( $cmd ) . ' ' .
2328                                 escapeshellarg(
2329                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2330                                         "MW_CPU_LIMIT=$time; " .
2331                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2332                                         "MW_MEM_LIMIT=$mem; " .
2333                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2334                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2335                                         "MW_USE_LOG_PIPE=yes"
2336                                 );
2337                         $useLogPipe = true;
2338                 } elseif ( $includeStderr ) {
2339                         $cmd .= ' 2>&1';
2340                 }
2341         } elseif ( $includeStderr ) {
2342                 $cmd .= ' 2>&1';
2343         }
2344         wfDebug( "wfShellExec: $cmd\n" );
2345
2346         // Don't try to execute commands that exceed Linux's MAX_ARG_STRLEN.
2347         // Other platforms may be more accomodating, but we don't want to be
2348         // accomodating, because very long commands probably include user
2349         // input. See T129506.
2350         if ( strlen( $cmd ) > SHELL_MAX_ARG_STRLEN ) {
2351                 throw new Exception( __METHOD__ .
2352                         '(): total length of $cmd must not exceed SHELL_MAX_ARG_STRLEN' );
2353         }
2354
2355         $desc = [
2356                 0 => [ 'file', 'php://stdin', 'r' ],
2357                 1 => [ 'pipe', 'w' ],
2358                 2 => [ 'file', 'php://stderr', 'w' ] ];
2359         if ( $useLogPipe ) {
2360                 $desc[3] = [ 'pipe', 'w' ];
2361         }
2362         $pipes = null;
2363         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2364         $proc = proc_open( $cmd, $desc, $pipes );
2365         if ( !$proc ) {
2366                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2367                 $retval = -1;
2368                 return '';
2369         }
2370         $outBuffer = $logBuffer = '';
2371         $emptyArray = [];
2372         $status = false;
2373         $logMsg = false;
2374
2375         /* According to the documentation, it is possible for stream_select()
2376          * to fail due to EINTR. I haven't managed to induce this in testing
2377          * despite sending various signals. If it did happen, the error
2378          * message would take the form:
2379          *
2380          * stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2381          *
2382          * where [4] is the value of the macro EINTR and "Interrupted system
2383          * call" is string which according to the Linux manual is "possibly"
2384          * localised according to LC_MESSAGES.
2385          */
2386         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2387         $eintrMessage = "stream_select(): unable to select [$eintr]";
2388
2389         $running = true;
2390         $timeout = null;
2391         $numReadyPipes = 0;
2392
2393         while ( $running === true || $numReadyPipes !== 0 ) {
2394                 if ( $running ) {
2395                         $status = proc_get_status( $proc );
2396                         // If the process has terminated, switch to nonblocking selects
2397                         // for getting any data still waiting to be read.
2398                         if ( !$status['running'] ) {
2399                                 $running = false;
2400                                 $timeout = 0;
2401                         }
2402                 }
2403
2404                 $readyPipes = $pipes;
2405
2406                 // Clear last error
2407                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2408                 @trigger_error( '' );
2409                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2410                 if ( $numReadyPipes === false ) {
2411                         // @codingStandardsIgnoreEnd
2412                         $error = error_get_last();
2413                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2414                                 continue;
2415                         } else {
2416                                 trigger_error( $error['message'], E_USER_WARNING );
2417                                 $logMsg = $error['message'];
2418                                 break;
2419                         }
2420                 }
2421                 foreach ( $readyPipes as $fd => $pipe ) {
2422                         $block = fread( $pipe, 65536 );
2423                         if ( $block === '' ) {
2424                                 // End of file
2425                                 fclose( $pipes[$fd] );
2426                                 unset( $pipes[$fd] );
2427                                 if ( !$pipes ) {
2428                                         break 2;
2429                                 }
2430                         } elseif ( $block === false ) {
2431                                 // Read error
2432                                 $logMsg = "Error reading from pipe";
2433                                 break 2;
2434                         } elseif ( $fd == 1 ) {
2435                                 // From stdout
2436                                 $outBuffer .= $block;
2437                         } elseif ( $fd == 3 ) {
2438                                 // From log FD
2439                                 $logBuffer .= $block;
2440                                 if ( strpos( $block, "\n" ) !== false ) {
2441                                         $lines = explode( "\n", $logBuffer );
2442                                         $logBuffer = array_pop( $lines );
2443                                         foreach ( $lines as $line ) {
2444                                                 wfDebugLog( 'exec', $line );
2445                                         }
2446                                 }
2447                         }
2448                 }
2449         }
2450
2451         foreach ( $pipes as $pipe ) {
2452                 fclose( $pipe );
2453         }
2454
2455         // Use the status previously collected if possible, since proc_get_status()
2456         // just calls waitpid() which will not return anything useful the second time.
2457         if ( $running ) {
2458                 $status = proc_get_status( $proc );
2459         }
2460
2461         if ( $logMsg !== false ) {
2462                 // Read/select error
2463                 $retval = -1;
2464                 proc_close( $proc );
2465         } elseif ( $status['signaled'] ) {
2466                 $logMsg = "Exited with signal {$status['termsig']}";
2467                 $retval = 128 + $status['termsig'];
2468                 proc_close( $proc );
2469         } else {
2470                 if ( $status['running'] ) {
2471                         $retval = proc_close( $proc );
2472                 } else {
2473                         $retval = $status['exitcode'];
2474                         proc_close( $proc );
2475                 }
2476                 if ( $retval == 127 ) {
2477                         $logMsg = "Possibly missing executable file";
2478                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2479                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2480                 }
2481         }
2482
2483         if ( $logMsg !== false ) {
2484                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2485         }
2486
2487         return $outBuffer;
2488 }
2489
2490 /**
2491  * Execute a shell command, returning both stdout and stderr. Convenience
2492  * function, as all the arguments to wfShellExec can become unwieldy.
2493  *
2494  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2495  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2496  *   or an array of unescaped arguments, in which case each value will be escaped
2497  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2498  * @param null|mixed &$retval Optional, will receive the program's exit code.
2499  *   (non-zero is usually failure)
2500  * @param array $environ Optional environment variables which should be
2501  *   added to the executed command environment.
2502  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2503  *   this overwrites the global wgMaxShell* limits.
2504  * @return string Collected stdout and stderr as a string
2505  */
2506 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2507         return wfShellExec( $cmd, $retval, $environ, $limits,
2508                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2509 }
2510
2511 /**
2512  * Workaround for http://bugs.php.net/bug.php?id=45132
2513  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2514  */
2515 function wfInitShellLocale() {
2516         static $done = false;
2517         if ( $done ) {
2518                 return;
2519         }
2520         $done = true;
2521         global $wgShellLocale;
2522         putenv( "LC_CTYPE=$wgShellLocale" );
2523         setlocale( LC_CTYPE, $wgShellLocale );
2524 }
2525
2526 /**
2527  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2528  * Note that $parameters should be a flat array and an option with an argument
2529  * should consist of two consecutive items in the array (do not use "--option value").
2530  *
2531  * @param string $script MediaWiki cli script path
2532  * @param array $parameters Arguments and options to the script
2533  * @param array $options Associative array of options:
2534  *              'php': The path to the php executable
2535  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2536  * @return string
2537  */
2538 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2539         global $wgPhpCli;
2540         // Give site config file a chance to run the script in a wrapper.
2541         // The caller may likely want to call wfBasename() on $script.
2542         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2543         $cmd = isset( $options['php'] ) ? [ $options['php'] ] : [ $wgPhpCli ];
2544         if ( isset( $options['wrapper'] ) ) {
2545                 $cmd[] = $options['wrapper'];
2546         }
2547         $cmd[] = $script;
2548         // Escape each parameter for shell
2549         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
2550 }
2551
2552 /**
2553  * wfMerge attempts to merge differences between three texts.
2554  * Returns true for a clean merge and false for failure or a conflict.
2555  *
2556  * @param string $old
2557  * @param string $mine
2558  * @param string $yours
2559  * @param string $result
2560  * @return bool
2561  */
2562 function wfMerge( $old, $mine, $yours, &$result ) {
2563         global $wgDiff3;
2564
2565         # This check may also protect against code injection in
2566         # case of broken installations.
2567         MediaWiki\suppressWarnings();
2568         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2569         MediaWiki\restoreWarnings();
2570
2571         if ( !$haveDiff3 ) {
2572                 wfDebug( "diff3 not found\n" );
2573                 return false;
2574         }
2575
2576         # Make temporary files
2577         $td = wfTempDir();
2578         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2579         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2580         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2581
2582         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2583         #       a newline character. To avoid this, we normalize the trailing whitespace before
2584         #       creating the diff.
2585
2586         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2587         fclose( $oldtextFile );
2588         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2589         fclose( $mytextFile );
2590         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2591         fclose( $yourtextFile );
2592
2593         # Check for a conflict
2594         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
2595                 $oldtextName, $yourtextName );
2596         $handle = popen( $cmd, 'r' );
2597
2598         if ( fgets( $handle, 1024 ) ) {
2599                 $conflict = true;
2600         } else {
2601                 $conflict = false;
2602         }
2603         pclose( $handle );
2604
2605         # Merge differences
2606         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2607                 $oldtextName, $yourtextName );
2608         $handle = popen( $cmd, 'r' );
2609         $result = '';
2610         do {
2611                 $data = fread( $handle, 8192 );
2612                 if ( strlen( $data ) == 0 ) {
2613                         break;
2614                 }
2615                 $result .= $data;
2616         } while ( true );
2617         pclose( $handle );
2618         unlink( $mytextName );
2619         unlink( $oldtextName );
2620         unlink( $yourtextName );
2621
2622         if ( $result === '' && $old !== '' && !$conflict ) {
2623                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2624                 $conflict = true;
2625         }
2626         return !$conflict;
2627 }
2628
2629 /**
2630  * Returns unified plain-text diff of two texts.
2631  * "Useful" for machine processing of diffs.
2632  *
2633  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2634  *
2635  * @param string $before The text before the changes.
2636  * @param string $after The text after the changes.
2637  * @param string $params Command-line options for the diff command.
2638  * @return string Unified diff of $before and $after
2639  */
2640 function wfDiff( $before, $after, $params = '-u' ) {
2641         if ( $before == $after ) {
2642                 return '';
2643         }
2644
2645         global $wgDiff;
2646         MediaWiki\suppressWarnings();
2647         $haveDiff = $wgDiff && file_exists( $wgDiff );
2648         MediaWiki\restoreWarnings();
2649
2650         # This check may also protect against code injection in
2651         # case of broken installations.
2652         if ( !$haveDiff ) {
2653                 wfDebug( "diff executable not found\n" );
2654                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2655                 $format = new UnifiedDiffFormatter();
2656                 return $format->format( $diffs );
2657         }
2658
2659         # Make temporary files
2660         $td = wfTempDir();
2661         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2662         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2663
2664         fwrite( $oldtextFile, $before );
2665         fclose( $oldtextFile );
2666         fwrite( $newtextFile, $after );
2667         fclose( $newtextFile );
2668
2669         // Get the diff of the two files
2670         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2671
2672         $h = popen( $cmd, 'r' );
2673         if ( !$h ) {
2674                 unlink( $oldtextName );
2675                 unlink( $newtextName );
2676                 throw new Exception( __METHOD__ . '(): popen() failed' );
2677         }
2678
2679         $diff = '';
2680
2681         do {
2682                 $data = fread( $h, 8192 );
2683                 if ( strlen( $data ) == 0 ) {
2684                         break;
2685                 }
2686                 $diff .= $data;
2687         } while ( true );
2688
2689         // Clean up
2690         pclose( $h );
2691         unlink( $oldtextName );
2692         unlink( $newtextName );
2693
2694         // Kill the --- and +++ lines. They're not useful.
2695         $diff_lines = explode( "\n", $diff );
2696         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2697                 unset( $diff_lines[0] );
2698         }
2699         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2700                 unset( $diff_lines[1] );
2701         }
2702
2703         $diff = implode( "\n", $diff_lines );
2704
2705         return $diff;
2706 }
2707
2708 /**
2709  * This function works like "use VERSION" in Perl, the program will die with a
2710  * backtrace if the current version of PHP is less than the version provided
2711  *
2712  * This is useful for extensions which due to their nature are not kept in sync
2713  * with releases, and might depend on other versions of PHP than the main code
2714  *
2715  * Note: PHP might die due to parsing errors in some cases before it ever
2716  *       manages to call this function, such is life
2717  *
2718  * @see perldoc -f use
2719  *
2720  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2721  * @throws MWException
2722  */
2723 function wfUsePHP( $req_ver ) {
2724         $php_ver = PHP_VERSION;
2725
2726         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2727                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2728         }
2729 }
2730
2731 /**
2732  * This function works like "use VERSION" in Perl except it checks the version
2733  * of MediaWiki, the program will die with a backtrace if the current version
2734  * of MediaWiki is less than the version provided.
2735  *
2736  * This is useful for extensions which due to their nature are not kept in sync
2737  * with releases
2738  *
2739  * Note: Due to the behavior of PHP's version_compare() which is used in this
2740  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2741  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2742  * targeted version number. For example if you wanted to allow any variation
2743  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2744  * not result in the same comparison due to the internal logic of
2745  * version_compare().
2746  *
2747  * @see perldoc -f use
2748  *
2749  * @deprecated since 1.26, use the "requires' property of extension.json
2750  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2751  * @throws MWException
2752  */
2753 function wfUseMW( $req_ver ) {
2754         global $wgVersion;
2755
2756         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2757                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2758         }
2759 }
2760
2761 /**
2762  * Return the final portion of a pathname.
2763  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2764  * http://bugs.php.net/bug.php?id=33898
2765  *
2766  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2767  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2768  *
2769  * @param string $path
2770  * @param string $suffix String to remove if present
2771  * @return string
2772  */
2773 function wfBaseName( $path, $suffix = '' ) {
2774         if ( $suffix == '' ) {
2775                 $encSuffix = '';
2776         } else {
2777                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2778         }
2779
2780         $matches = [];
2781         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2782                 return $matches[1];
2783         } else {
2784                 return '';
2785         }
2786 }
2787
2788 /**
2789  * Generate a relative path name to the given file.
2790  * May explode on non-matching case-insensitive paths,
2791  * funky symlinks, etc.
2792  *
2793  * @param string $path Absolute destination path including target filename
2794  * @param string $from Absolute source path, directory only
2795  * @return string
2796  */
2797 function wfRelativePath( $path, $from ) {
2798         // Normalize mixed input on Windows...
2799         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2800         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2801
2802         // Trim trailing slashes -- fix for drive root
2803         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2804         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2805
2806         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2807         $against = explode( DIRECTORY_SEPARATOR, $from );
2808
2809         if ( $pieces[0] !== $against[0] ) {
2810                 // Non-matching Windows drive letters?
2811                 // Return a full path.
2812                 return $path;
2813         }
2814
2815         // Trim off common prefix
2816         while ( count( $pieces ) && count( $against )
2817                 && $pieces[0] == $against[0] ) {
2818                 array_shift( $pieces );
2819                 array_shift( $against );
2820         }
2821
2822         // relative dots to bump us to the parent
2823         while ( count( $against ) ) {
2824                 array_unshift( $pieces, '..' );
2825                 array_shift( $against );
2826         }
2827
2828         array_push( $pieces, wfBaseName( $path ) );
2829
2830         return implode( DIRECTORY_SEPARATOR, $pieces );
2831 }
2832
2833 /**
2834  * Convert an arbitrarily-long digit string from one numeric base
2835  * to another, optionally zero-padding to a minimum column width.
2836  *
2837  * Supports base 2 through 36; digit values 10-36 are represented
2838  * as lowercase letters a-z. Input is case-insensitive.
2839  *
2840  * @deprecated since 1.27 Use Wikimedia\base_convert() directly
2841  *
2842  * @param string $input Input number
2843  * @param int $sourceBase Base of the input number
2844  * @param int $destBase Desired base of the output
2845  * @param int $pad Minimum number of digits in the output (pad with zeroes)
2846  * @param bool $lowercase Whether to output in lowercase or uppercase
2847  * @param string $engine Either "gmp", "bcmath", or "php"
2848  * @return string|bool The output number as a string, or false on error
2849  */
2850 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
2851         $lowercase = true, $engine = 'auto'
2852 ) {
2853         return Wikimedia\base_convert( $input, $sourceBase, $destBase, $pad, $lowercase, $engine );
2854 }
2855
2856 /**
2857  * @deprecated since 1.27, PHP's session generation isn't used with
2858  *  MediaWiki\Session\SessionManager
2859  */
2860 function wfFixSessionID() {
2861         wfDeprecated( __FUNCTION__, '1.27' );
2862 }
2863
2864 /**
2865  * Reset the session id
2866  *
2867  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2868  * @since 1.22
2869  */
2870 function wfResetSessionID() {
2871         wfDeprecated( __FUNCTION__, '1.27' );
2872         $session = SessionManager::getGlobalSession();
2873         $delay = $session->delaySave();
2874
2875         $session->resetId();
2876
2877         // Make sure a session is started, since that's what the old
2878         // wfResetSessionID() did.
2879         if ( session_id() !== $session->getId() ) {
2880                 wfSetupSession( $session->getId() );
2881         }
2882
2883         ScopedCallback::consume( $delay );
2884 }
2885
2886 /**
2887  * Initialise php session
2888  *
2889  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2890  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2891  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2892  *  here), then calling $session->persist().
2893  * @param bool|string $sessionId
2894  */
2895 function wfSetupSession( $sessionId = false ) {
2896         wfDeprecated( __FUNCTION__, '1.27' );
2897
2898         if ( $sessionId ) {
2899                 session_id( $sessionId );
2900         }
2901
2902         $session = SessionManager::getGlobalSession();
2903         $session->persist();
2904
2905         if ( session_id() !== $session->getId() ) {
2906                 session_id( $session->getId() );
2907         }
2908         MediaWiki\quietCall( 'session_start' );
2909 }
2910
2911 /**
2912  * Get an object from the precompiled serialized directory
2913  *
2914  * @param string $name
2915  * @return mixed The variable on success, false on failure
2916  */
2917 function wfGetPrecompiledData( $name ) {
2918         global $IP;
2919
2920         $file = "$IP/serialized/$name";
2921         if ( file_exists( $file ) ) {
2922                 $blob = file_get_contents( $file );
2923                 if ( $blob ) {
2924                         return unserialize( $blob );
2925                 }
2926         }
2927         return false;
2928 }
2929
2930 /**
2931  * Make a cache key for the local wiki.
2932  *
2933  * @param string $args,...
2934  * @return string
2935  */
2936 function wfMemcKey( /*...*/ ) {
2937         return call_user_func_array(
2938                 [ ObjectCache::getLocalClusterInstance(), 'makeKey' ],
2939                 func_get_args()
2940         );
2941 }
2942
2943 /**
2944  * Make a cache key for a foreign DB.
2945  *
2946  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2947  *
2948  * @param string $db
2949  * @param string $prefix
2950  * @param string $args,...
2951  * @return string
2952  */
2953 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
2954         $args = array_slice( func_get_args(), 2 );
2955         $keyspace = $prefix ? "$db-$prefix" : $db;
2956         return call_user_func_array(
2957                 [ ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ],
2958                 [ $keyspace, $args ]
2959         );
2960 }
2961
2962 /**
2963  * Make a cache key with database-agnostic prefix.
2964  *
2965  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
2966  * instead. Must have a prefix as otherwise keys that use a database name
2967  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
2968  *
2969  * @since 1.26
2970  * @param string $args,...
2971  * @return string
2972  */
2973 function wfGlobalCacheKey( /*...*/ ) {
2974         return call_user_func_array(
2975                 [ ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ],
2976                 func_get_args()
2977         );
2978 }
2979
2980 /**
2981  * Get an ASCII string identifying this wiki
2982  * This is used as a prefix in memcached keys
2983  *
2984  * @return string
2985  */
2986 function wfWikiID() {
2987         global $wgDBprefix, $wgDBname;
2988         if ( $wgDBprefix ) {
2989                 return "$wgDBname-$wgDBprefix";
2990         } else {
2991                 return $wgDBname;
2992         }
2993 }
2994
2995 /**
2996  * Split a wiki ID into DB name and table prefix
2997  *
2998  * @param string $wiki
2999  *
3000  * @return array
3001  */
3002 function wfSplitWikiID( $wiki ) {
3003         $bits = explode( '-', $wiki, 2 );
3004         if ( count( $bits ) < 2 ) {
3005                 $bits[] = '';
3006         }
3007         return $bits;
3008 }
3009
3010 /**
3011  * Get a Database object.
3012  *
3013  * @param int $db Index of the connection to get. May be DB_MASTER for the
3014  *            master (for write queries), DB_REPLICA for potentially lagged read
3015  *            queries, or an integer >= 0 for a particular server.
3016  *
3017  * @param string|string[] $groups Query groups. An array of group names that this query
3018  *                belongs to. May contain a single string if the query is only
3019  *                in one group.
3020  *
3021  * @param string|bool $wiki The wiki ID, or false for the current wiki
3022  *
3023  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
3024  * will always return the same object, unless the underlying connection or load
3025  * balancer is manually destroyed.
3026  *
3027  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3028  * updater to ensure that a proper database is being updated.
3029  *
3030  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
3031  *       on an injected instance of LoadBalancer.
3032  *
3033  * @return DatabaseBase
3034  */
3035 function wfGetDB( $db, $groups = [], $wiki = false ) {
3036         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3037 }
3038
3039 /**
3040  * Get a load balancer object.
3041  *
3042  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancer()
3043  *              or MediaWikiServices::getDBLoadBalancerFactory() instead.
3044  *
3045  * @param string|bool $wiki Wiki ID, or false for the current wiki
3046  * @return LoadBalancer
3047  */
3048 function wfGetLB( $wiki = false ) {
3049         if ( $wiki === false ) {
3050                 return \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancer();
3051         } else {
3052                 $factory = \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
3053                 return $factory->getMainLB( $wiki );
3054         }
3055 }
3056
3057 /**
3058  * Get the load balancer factory object
3059  *
3060  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancerFactory() instead.
3061  *
3062  * @return LBFactory
3063  */
3064 function wfGetLBFactory() {
3065         return \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
3066 }
3067
3068 /**
3069  * Find a file.
3070  * Shortcut for RepoGroup::singleton()->findFile()
3071  *
3072  * @param string $title String or Title object
3073  * @param array $options Associative array of options (see RepoGroup::findFile)
3074  * @return File|bool File, or false if the file does not exist
3075  */
3076 function wfFindFile( $title, $options = [] ) {
3077         return RepoGroup::singleton()->findFile( $title, $options );
3078 }
3079
3080 /**
3081  * Get an object referring to a locally registered file.
3082  * Returns a valid placeholder object if the file does not exist.
3083  *
3084  * @param Title|string $title
3085  * @return LocalFile|null A File, or null if passed an invalid Title
3086  */
3087 function wfLocalFile( $title ) {
3088         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3089 }
3090
3091 /**
3092  * Should low-performance queries be disabled?
3093  *
3094  * @return bool
3095  * @codeCoverageIgnore
3096  */
3097 function wfQueriesMustScale() {
3098         global $wgMiserMode;
3099         return $wgMiserMode
3100                 || ( SiteStats::pages() > 100000
3101                 && SiteStats::edits() > 1000000
3102                 && SiteStats::users() > 10000 );
3103 }
3104
3105 /**
3106  * Get the path to a specified script file, respecting file
3107  * extensions; this is a wrapper around $wgScriptPath etc.
3108  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3109  *
3110  * @param string $script Script filename, sans extension
3111  * @return string
3112  */
3113 function wfScript( $script = 'index' ) {
3114         global $wgScriptPath, $wgScript, $wgLoadScript;
3115         if ( $script === 'index' ) {
3116                 return $wgScript;
3117         } elseif ( $script === 'load' ) {
3118                 return $wgLoadScript;
3119         } else {
3120                 return "{$wgScriptPath}/{$script}.php";
3121         }
3122 }
3123
3124 /**
3125  * Get the script URL.
3126  *
3127  * @return string Script URL
3128  */
3129 function wfGetScriptUrl() {
3130         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3131                 /* as it was called, minus the query string.
3132                  *
3133                  * Some sites use Apache rewrite rules to handle subdomains,
3134                  * and have PHP set up in a weird way that causes PHP_SELF
3135                  * to contain the rewritten URL instead of the one that the
3136                  * outside world sees.
3137                  *
3138                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
3139                  * provides containing the "before" URL.
3140                  */
3141                 return $_SERVER['SCRIPT_NAME'];
3142         } else {
3143                 return $_SERVER['URL'];
3144         }
3145 }
3146
3147 /**
3148  * Convenience function converts boolean values into "true"
3149  * or "false" (string) values
3150  *
3151  * @param bool $value
3152  * @return string
3153  */
3154 function wfBoolToStr( $value ) {
3155         return $value ? 'true' : 'false';
3156 }
3157
3158 /**
3159  * Get a platform-independent path to the null file, e.g. /dev/null
3160  *
3161  * @return string
3162  */
3163 function wfGetNull() {
3164         return wfIsWindows() ? 'NUL' : '/dev/null';
3165 }
3166
3167 /**
3168  * Waits for the replica DBs to catch up to the master position
3169  *
3170  * Use this when updating very large numbers of rows, as in maintenance scripts,
3171  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
3172  *
3173  * By default this waits on the main DB cluster of the current wiki.
3174  * If $cluster is set to "*" it will wait on all DB clusters, including
3175  * external ones. If the lag being waiting on is caused by the code that
3176  * does this check, it makes since to use $ifWritesSince, particularly if
3177  * cluster is "*", to avoid excess overhead.
3178  *
3179  * Never call this function after a big DB write that is still in a transaction.
3180  * This only makes sense after the possible lag inducing changes were committed.
3181  *
3182  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3183  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3184  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3185  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3186  * @return bool Success (able to connect and no timeouts reached)
3187  * @deprecated since 1.27 Use LBFactory::waitForReplication
3188  */
3189 function wfWaitForSlaves(
3190         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3191 ) {
3192         if ( $timeout === null ) {
3193                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3194         }
3195
3196         if ( $cluster === '*' ) {
3197                 $cluster = false;
3198                 $wiki = false;
3199         } elseif ( $wiki === false ) {
3200                 $wiki = wfWikiID();
3201         }
3202
3203         try {
3204                 wfGetLBFactory()->waitForReplication( [
3205                         'wiki' => $wiki,
3206                         'cluster' => $cluster,
3207                         'timeout' => $timeout,
3208                         // B/C: first argument used to be "max seconds of lag"; ignore such values
3209                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
3210                 ] );
3211         } catch ( DBReplicationWaitError $e ) {
3212                 return false;
3213         }
3214
3215         return true;
3216 }
3217
3218 /**
3219  * Count down from $seconds to zero on the terminal, with a one-second pause
3220  * between showing each number. For use in command-line scripts.
3221  *
3222  * @codeCoverageIgnore
3223  * @param int $seconds
3224  */
3225 function wfCountDown( $seconds ) {
3226         for ( $i = $seconds; $i >= 0; $i-- ) {
3227                 if ( $i != $seconds ) {
3228                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3229                 }
3230                 echo $i;
3231                 flush();
3232                 if ( $i ) {
3233                         sleep( 1 );
3234                 }
3235         }
3236         echo "\n";
3237 }
3238
3239 /**
3240  * Replace all invalid characters with '-'.
3241  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
3242  * By default, $wgIllegalFileChars includes ':', '/', '\'.
3243  *
3244  * @param string $name Filename to process
3245  * @return string
3246  */
3247 function wfStripIllegalFilenameChars( $name ) {
3248         global $wgIllegalFileChars;
3249         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3250         $name = preg_replace(
3251                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3252                 '-',
3253                 $name
3254         );
3255         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
3256         $name = wfBaseName( $name );
3257         return $name;
3258 }
3259
3260 /**
3261  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3262  *
3263  * @return int Resulting value of the memory limit.
3264  */
3265 function wfMemoryLimit() {
3266         global $wgMemoryLimit;
3267         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3268         if ( $memlimit != -1 ) {
3269                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3270                 if ( $conflimit == -1 ) {
3271                         wfDebug( "Removing PHP's memory limit\n" );
3272                         MediaWiki\suppressWarnings();
3273                         ini_set( 'memory_limit', $conflimit );
3274                         MediaWiki\restoreWarnings();
3275                         return $conflimit;
3276                 } elseif ( $conflimit > $memlimit ) {
3277                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3278                         MediaWiki\suppressWarnings();
3279                         ini_set( 'memory_limit', $conflimit );
3280                         MediaWiki\restoreWarnings();
3281                         return $conflimit;
3282                 }
3283         }
3284         return $memlimit;
3285 }
3286
3287 /**
3288  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3289  *
3290  * @return int Prior time limit
3291  * @since 1.26
3292  */
3293 function wfTransactionalTimeLimit() {
3294         global $wgTransactionalTimeLimit;
3295
3296         $timeLimit = ini_get( 'max_execution_time' );
3297         // Note that CLI scripts use 0
3298         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3299                 set_time_limit( $wgTransactionalTimeLimit );
3300         }
3301
3302         ignore_user_abort( true ); // ignore client disconnects
3303
3304         return $timeLimit;
3305 }
3306
3307 /**
3308  * Converts shorthand byte notation to integer form
3309  *
3310  * @param string $string
3311  * @param int $default Returned if $string is empty
3312  * @return int
3313  */
3314 function wfShorthandToInteger( $string = '', $default = -1 ) {
3315         $string = trim( $string );
3316         if ( $string === '' ) {
3317                 return $default;
3318         }
3319         $last = $string[strlen( $string ) - 1];
3320         $val = intval( $string );
3321         switch ( $last ) {
3322                 case 'g':
3323                 case 'G':
3324                         $val *= 1024;
3325                         // break intentionally missing
3326                 case 'm':
3327                 case 'M':
3328                         $val *= 1024;
3329                         // break intentionally missing
3330                 case 'k':
3331                 case 'K':
3332                         $val *= 1024;
3333         }
3334
3335         return $val;
3336 }
3337
3338 /**
3339  * Get the normalised IETF language tag
3340  * See unit test for examples.
3341  *
3342  * @param string $code The language code.
3343  * @return string The language code which complying with BCP 47 standards.
3344  */
3345 function wfBCP47( $code ) {
3346         $codeSegment = explode( '-', $code );
3347         $codeBCP = [];
3348         foreach ( $codeSegment as $segNo => $seg ) {
3349                 // when previous segment is x, it is a private segment and should be lc
3350                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3351                         $codeBCP[$segNo] = strtolower( $seg );
3352                 // ISO 3166 country code
3353                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3354                         $codeBCP[$segNo] = strtoupper( $seg );
3355                 // ISO 15924 script code
3356                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3357                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3358                 // Use lowercase for other cases
3359                 } else {
3360                         $codeBCP[$segNo] = strtolower( $seg );
3361                 }
3362         }
3363         $langCode = implode( '-', $codeBCP );
3364         return $langCode;
3365 }
3366
3367 /**
3368  * Get a specific cache object.
3369  *
3370  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3371  * @return BagOStuff
3372  */
3373 function wfGetCache( $cacheType ) {
3374         return ObjectCache::getInstance( $cacheType );
3375 }
3376
3377 /**
3378  * Get the main cache object
3379  *
3380  * @return BagOStuff
3381  */
3382 function wfGetMainCache() {
3383         global $wgMainCacheType;
3384         return ObjectCache::getInstance( $wgMainCacheType );
3385 }
3386
3387 /**
3388  * Get the cache object used by the message cache
3389  *
3390  * @return BagOStuff
3391  */
3392 function wfGetMessageCacheStorage() {
3393         global $wgMessageCacheType;
3394         return ObjectCache::getInstance( $wgMessageCacheType );
3395 }
3396
3397 /**
3398  * Get the cache object used by the parser cache
3399  *
3400  * @return BagOStuff
3401  */
3402 function wfGetParserCacheStorage() {
3403         global $wgParserCacheType;
3404         return ObjectCache::getInstance( $wgParserCacheType );
3405 }
3406
3407 /**
3408  * Call hook functions defined in $wgHooks
3409  *
3410  * @param string $event Event name
3411  * @param array $args Parameters passed to hook functions
3412  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3413  *
3414  * @return bool True if no handler aborted the hook
3415  * @deprecated since 1.25 - use Hooks::run
3416  */
3417 function wfRunHooks( $event, array $args = [], $deprecatedVersion = null ) {
3418         return Hooks::run( $event, $args, $deprecatedVersion );
3419 }
3420
3421 /**
3422  * Wrapper around php's unpack.
3423  *
3424  * @param string $format The format string (See php's docs)
3425  * @param string $data A binary string of binary data
3426  * @param int|bool $length The minimum length of $data or false. This is to
3427  *      prevent reading beyond the end of $data. false to disable the check.
3428  *
3429  * Also be careful when using this function to read unsigned 32 bit integer
3430  * because php might make it negative.
3431  *
3432  * @throws MWException If $data not long enough, or if unpack fails
3433  * @return array Associative array of the extracted data
3434  */
3435 function wfUnpack( $format, $data, $length = false ) {
3436         if ( $length !== false ) {
3437                 $realLen = strlen( $data );
3438                 if ( $realLen < $length ) {
3439                         throw new MWException( "Tried to use wfUnpack on a "
3440                                 . "string of length $realLen, but needed one "
3441                                 . "of at least length $length."
3442                         );
3443                 }
3444         }
3445
3446         MediaWiki\suppressWarnings();
3447         $result = unpack( $format, $data );
3448         MediaWiki\restoreWarnings();
3449
3450         if ( $result === false ) {
3451                 // If it cannot extract the packed data.
3452                 throw new MWException( "unpack could not unpack binary data" );
3453         }
3454         return $result;
3455 }
3456
3457 /**
3458  * Determine if an image exists on the 'bad image list'.
3459  *
3460  * The format of MediaWiki:Bad_image_list is as follows:
3461  *    * Only list items (lines starting with "*") are considered
3462  *    * The first link on a line must be a link to a bad image
3463  *    * Any subsequent links on the same line are considered to be exceptions,
3464  *      i.e. articles where the image may occur inline.
3465  *
3466  * @param string $name The image name to check
3467  * @param Title|bool $contextTitle The page on which the image occurs, if known
3468  * @param string $blacklist Wikitext of a file blacklist
3469  * @return bool
3470  */
3471 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3472         # Handle redirects; callers almost always hit wfFindFile() anyway,
3473         # so just use that method because it has a fast process cache.
3474         $file = wfFindFile( $name ); // get the final name
3475         $name = $file ? $file->getTitle()->getDBkey() : $name;
3476
3477         # Run the extension hook
3478         $bad = false;
3479         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3480                 return $bad;
3481         }
3482
3483         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3484         $key = wfMemcKey( 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist ) );
3485         $badImages = $cache->get( $key );
3486
3487         if ( $badImages === false ) { // cache miss
3488                 if ( $blacklist === null ) {
3489                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3490                 }
3491                 # Build the list now
3492                 $badImages = [];
3493                 $lines = explode( "\n", $blacklist );
3494                 foreach ( $lines as $line ) {
3495                         # List items only
3496                         if ( substr( $line, 0, 1 ) !== '*' ) {
3497                                 continue;
3498                         }
3499
3500                         # Find all links
3501                         $m = [];
3502                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3503                                 continue;
3504                         }
3505
3506                         $exceptions = [];
3507                         $imageDBkey = false;
3508                         foreach ( $m[1] as $i => $titleText ) {
3509                                 $title = Title::newFromText( $titleText );
3510                                 if ( !is_null( $title ) ) {
3511                                         if ( $i == 0 ) {
3512                                                 $imageDBkey = $title->getDBkey();
3513                                         } else {
3514                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3515                                         }
3516                                 }
3517                         }
3518
3519                         if ( $imageDBkey !== false ) {
3520                                 $badImages[$imageDBkey] = $exceptions;
3521                         }
3522                 }
3523                 $cache->set( $key, $badImages, 60 );
3524         }
3525
3526         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3527         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3528
3529         return $bad;
3530 }
3531
3532 /**
3533  * Determine whether the client at a given source IP is likely to be able to
3534  * access the wiki via HTTPS.
3535  *
3536  * @param string $ip The IPv4/6 address in the normal human-readable form
3537  * @return bool
3538  */
3539 function wfCanIPUseHTTPS( $ip ) {
3540         $canDo = true;
3541         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3542         return !!$canDo;
3543 }
3544
3545 /**
3546  * Determine input string is represents as infinity
3547  *
3548  * @param string $str The string to determine
3549  * @return bool
3550  * @since 1.25
3551  */
3552 function wfIsInfinity( $str ) {
3553         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3554         return in_array( $str, $infinityValues );
3555 }
3556
3557 /**
3558  * Returns true if these thumbnail parameters match one that MediaWiki
3559  * requests from file description pages and/or parser output.
3560  *
3561  * $params is considered non-standard if they involve a non-standard
3562  * width or any non-default parameters aside from width and page number.
3563  * The number of possible files with standard parameters is far less than
3564  * that of all combinations; rate-limiting for them can thus be more generious.
3565  *
3566  * @param File $file
3567  * @param array $params
3568  * @return bool
3569  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3570  */
3571 function wfThumbIsStandard( File $file, array $params ) {
3572         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3573
3574         $multipliers = [ 1 ];
3575         if ( $wgResponsiveImages ) {
3576                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3577                 // @see Linker::processResponsiveImages
3578                 $multipliers[] = 1.5;
3579                 $multipliers[] = 2;
3580         }
3581
3582         $handler = $file->getHandler();
3583         if ( !$handler || !isset( $params['width'] ) ) {
3584                 return false;
3585         }
3586
3587         $basicParams = [];
3588         if ( isset( $params['page'] ) ) {
3589                 $basicParams['page'] = $params['page'];
3590         }
3591
3592         $thumbLimits = [];
3593         $imageLimits = [];
3594         // Expand limits to account for multipliers
3595         foreach ( $multipliers as $multiplier ) {
3596                 $thumbLimits = array_merge( $thumbLimits, array_map(
3597                         function ( $width ) use ( $multiplier ) {
3598                                 return round( $width * $multiplier );
3599                         }, $wgThumbLimits )
3600                 );
3601                 $imageLimits = array_merge( $imageLimits, array_map(
3602                         function ( $pair ) use ( $multiplier ) {
3603                                 return [
3604                                         round( $pair[0] * $multiplier ),
3605                                         round( $pair[1] * $multiplier ),
3606                                 ];
3607                         }, $wgImageLimits )
3608                 );
3609         }
3610
3611         // Check if the width matches one of $wgThumbLimits
3612         if ( in_array( $params['width'], $thumbLimits ) ) {
3613                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3614                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3615                 $handler->normaliseParams( $file, $normalParams );
3616         } else {
3617                 // If not, then check if the width matchs one of $wgImageLimits
3618                 $match = false;
3619                 foreach ( $imageLimits as $pair ) {
3620                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3621                         // Decide whether the thumbnail should be scaled on width or height.
3622                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3623                         $handler->normaliseParams( $file, $normalParams );
3624                         // Check if this standard thumbnail size maps to the given width
3625                         if ( $normalParams['width'] == $params['width'] ) {
3626                                 $match = true;
3627                                 break;
3628                         }
3629                 }
3630                 if ( !$match ) {
3631                         return false; // not standard for description pages
3632                 }
3633         }
3634
3635         // Check that the given values for non-page, non-width, params are just defaults
3636         foreach ( $params as $key => $value ) {
3637                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3638                         return false;
3639                 }
3640         }
3641
3642         return true;
3643 }
3644
3645 /**
3646  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3647  *
3648  * Values that exist in both values will be combined with += (all values of the array
3649  * of $newValues will be added to the values of the array of $baseArray, while values,
3650  * that exists in both, the value of $baseArray will be used).
3651  *
3652  * @param array $baseArray The array where you want to add the values of $newValues to
3653  * @param array $newValues An array with new values
3654  * @return array The combined array
3655  * @since 1.26
3656  */
3657 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3658         // First merge items that are in both arrays
3659         foreach ( $baseArray as $name => &$groupVal ) {
3660                 if ( isset( $newValues[$name] ) ) {
3661                         $groupVal += $newValues[$name];
3662                 }
3663         }
3664         // Now add items that didn't exist yet
3665         $baseArray += $newValues;
3666
3667         return $baseArray;
3668 }