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 use Wikimedia\ScopedCallback;
  31
  32 // Hide compatibility functions from Doxygen
  33 /// @cond
  34 /**
  35  * Compatibility functions
  36  *
  37  * We support PHP 5.5.9 and up.
  38  * Re-implementations of newer functions or functions in non-standard
  39  * PHP extensions may be included here.
  40  */
  41
  42 // hash_equals function only exists in PHP >= 5.6.0
  43 // https://secure.php.net/hash_equals
  44 if ( !function_exists( 'hash_equals' ) ) {
  45         /**
  46          * Check whether a user-provided string is equal to a fixed-length secret string
  47          * without revealing bytes of the secret string through timing differences.
  48          *
  49          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
  50          * function in C) is to compare corresponding bytes and stop at the first difference,
  51          * which would take longer for a partial match than for a complete mismatch. This
  52          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
  53          * and the other may come from an attacker. Statistical analysis of timing measurements
  54          * over many requests may allow the attacker to guess the string's bytes one at a time
  55          * (and check his guesses) even if the timing differences are extremely small.
  56          *
  57          * When making such a security-sensitive comparison, it is essential that the sequence
  58          * in which instructions are executed and memory locations are accessed not depend on
  59          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
  60          * the inevitable leakage of the string's length. That is generally known anyway as
  61          * a chararacteristic of the hash function used to compute the secret value.
  62          *
  63          * Longer explanation: http://www.emerose.com/timing-attacks-explained
  64          *
  65          * @codeCoverageIgnore
  66          * @param string $known_string Fixed-length secret string to compare against
  67          * @param string $user_string User-provided string
  68          * @return bool True if the strings are the same, false otherwise
  69          */
  70         function hash_equals( $known_string, $user_string ) {
  71                 // Strict type checking as in PHP's native implementation
  72                 if ( !is_string( $known_string ) ) {
  73                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
  74                                 gettype( $known_string ) . ' given', E_USER_WARNING );
  75
  76                         return false;
  77                 }
  78
  79                 if ( !is_string( $user_string ) ) {
  80                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
  81                                 gettype( $user_string ) . ' given', E_USER_WARNING );
  82
  83                         return false;
  84                 }
  85
  86                 $known_string_len = strlen( $known_string );
  87                 if ( $known_string_len !== strlen( $user_string ) ) {
  88                         return false;
  89                 }
  90
  91                 $result = 0;
  92                 for ( $i = 0; $i < $known_string_len; $i++ ) {
  93                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
  94                 }
  95
  96                 return ( $result === 0 );
  97         }
  98 }
  99 /// @endcond
 100
 101 /**
 102  * Load an extension
 103  *
 104  * This queues an extension to be loaded through
 105  * the ExtensionRegistry system.
 106  *
 107  * @param string $ext Name of the extension to load
 108  * @param string|null $path Absolute path of where to find the extension.json file
 109  * @since 1.25
 110  */
 111 function wfLoadExtension( $ext, $path = null ) {
 112         if ( !$path ) {
 113                 global $wgExtensionDirectory;
 114                 $path = "$wgExtensionDirectory/$ext/extension.json";
 115         }
 116         ExtensionRegistry::getInstance()->queue( $path );
 117 }
 118
 119 /**
 120  * Load multiple extensions at once
 121  *
 122  * Same as wfLoadExtension, but more efficient if you
 123  * are loading multiple extensions.
 124  *
 125  * If you want to specify custom paths, you should interact with
 126  * ExtensionRegistry directly.
 127  *
 128  * @see wfLoadExtension
 129  * @param string[] $exts Array of extension names to load
 130  * @since 1.25
 131  */
 132 function wfLoadExtensions( array $exts ) {
 133         global $wgExtensionDirectory;
 134         $registry = ExtensionRegistry::getInstance();
 135         foreach ( $exts as $ext ) {
 136                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 137         }
 138 }
 139
 140 /**
 141  * Load a skin
 142  *
 143  * @see wfLoadExtension
 144  * @param string $skin Name of the extension to load
 145  * @param string|null $path Absolute path of where to find the skin.json file
 146  * @since 1.25
 147  */
 148 function wfLoadSkin( $skin, $path = null ) {
 149         if ( !$path ) {
 150                 global $wgStyleDirectory;
 151                 $path = "$wgStyleDirectory/$skin/skin.json";
 152         }
 153         ExtensionRegistry::getInstance()->queue( $path );
 154 }
 155
 156 /**
 157  * Load multiple skins at once
 158  *
 159  * @see wfLoadExtensions
 160  * @param string[] $skins Array of extension names to load
 161  * @since 1.25
 162  */
 163 function wfLoadSkins( array $skins ) {
 164         global $wgStyleDirectory;
 165         $registry = ExtensionRegistry::getInstance();
 166         foreach ( $skins as $skin ) {
 167                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 168         }
 169 }
 170
 171 /**
 172  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 173  * @param array $a
 174  * @param array $b
 175  * @return array
 176  */
 177 function wfArrayDiff2( $a, $b ) {
 178         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 179 }
 180
 181 /**
 182  * @param array|string $a
 183  * @param array|string $b
 184  * @return int
 185  */
 186 function wfArrayDiff2_cmp( $a, $b ) {
 187         if ( is_string( $a ) && is_string( $b ) ) {
 188                 return strcmp( $a, $b );
 189         } elseif ( count( $a ) !== count( $b ) ) {
 190                 return count( $a ) < count( $b ) ? -1 : 1;
 191         } else {
 192                 reset( $a );
 193                 reset( $b );
 194                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 195                         $cmp = strcmp( $valueA, $valueB );
 196                         if ( $cmp !== 0 ) {
 197                                 return $cmp;
 198                         }
 199                 }
 200                 return 0;
 201         }
 202 }
 203
 204 /**
 205  * Appends to second array if $value differs from that in $default
 206  *
 207  * @param string|int $key
 208  * @param mixed $value
 209  * @param mixed $default
 210  * @param array $changed Array to alter
 211  * @throws MWException
 212  */
 213 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 214         if ( is_null( $changed ) ) {
 215                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 216         }
 217         if ( $default[$key] !== $value ) {
 218                 $changed[$key] = $value;
 219         }
 220 }
 221
 222 /**
 223  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 224  * e.g.
 225  *      wfMergeErrorArrays(
 226  *              [ [ 'x' ] ],
 227  *              [ [ 'x', '2' ] ],
 228  *              [ [ 'x' ] ],
 229  *              [ [ 'y' ] ]
 230  *      );
 231  * returns:
 232  *              [
 233  *              [ 'x', '2' ],
 234  *              [ 'x' ],
 235  *              [ 'y' ]
 236  *      ]
 237  *
 238  * @param array $array1,...
 239  * @return array
 240  */
 241 function wfMergeErrorArrays( /*...*/ ) {
 242         $args = func_get_args();
 243         $out = [];
 244         foreach ( $args as $errors ) {
 245                 foreach ( $errors as $params ) {
 246                         $originalParams = $params;
 247                         if ( $params[0] instanceof MessageSpecifier ) {
 248                                 $msg = $params[0];
 249                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 250                         }
 251                         # @todo FIXME: Sometimes get nested arrays for $params,
 252                         # which leads to E_NOTICEs
 253                         $spec = implode( "\t", $params );
 254                         $out[$spec] = $originalParams;
 255                 }
 256         }
 257         return array_values( $out );
 258 }
 259
 260 /**
 261  * Insert array into another array after the specified *KEY*
 262  *
 263  * @param array $array The array.
 264  * @param array $insert The array to insert.
 265  * @param mixed $after The key to insert after
 266  * @return array
 267  */
 268 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 269         // Find the offset of the element to insert after.
 270         $keys = array_keys( $array );
 271         $offsetByKey = array_flip( $keys );
 272
 273         $offset = $offsetByKey[$after];
 274
 275         // Insert at the specified offset
 276         $before = array_slice( $array, 0, $offset + 1, true );
 277         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 278
 279         $output = $before + $insert + $after;
 280
 281         return $output;
 282 }
 283
 284 /**
 285  * Recursively converts the parameter (an object) to an array with the same data
 286  *
 287  * @param object|array $objOrArray
 288  * @param bool $recursive
 289  * @return array
 290  */
 291 function wfObjectToArray( $objOrArray, $recursive = true ) {
 292         $array = [];
 293         if ( is_object( $objOrArray ) ) {
 294                 $objOrArray = get_object_vars( $objOrArray );
 295         }
 296         foreach ( $objOrArray as $key => $value ) {
 297                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 298                         $value = wfObjectToArray( $value );
 299                 }
 300
 301                 $array[$key] = $value;
 302         }
 303
 304         return $array;
 305 }
 306
 307 /**
 308  * Get a random decimal value between 0 and 1, in a way
 309  * not likely to give duplicate values for any realistic
 310  * number of articles.
 311  *
 312  * @note This is designed for use in relation to Special:RandomPage
 313  *       and the page_random database field.
 314  *
 315  * @return string
 316  */
 317 function wfRandom() {
 318         // The maximum random value is "only" 2^31-1, so get two random
 319         // values to reduce the chance of dupes
 320         $max = mt_getrandmax() + 1;
 321         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 322         return $rand;
 323 }
 324
 325 /**
 326  * Get a random string containing a number of pseudo-random hex characters.
 327  *
 328  * @note This is not secure, if you are trying to generate some sort
 329  *       of token please use MWCryptRand instead.
 330  *
 331  * @param int $length The length of the string to generate
 332  * @return string
 333  * @since 1.20
 334  */
 335 function wfRandomString( $length = 32 ) {
 336         $str = '';
 337         for ( $n = 0; $n < $length; $n += 7 ) {
 338                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 339         }
 340         return substr( $str, 0, $length );
 341 }
 342
 343 /**
 344  * We want some things to be included as literal characters in our title URLs
 345  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 346  * all of the following should be safe:
 347  *
 348  * ;:@&=$-_.+!*'(),
 349  *
 350  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 351  * character which should not be encoded. More importantly, google chrome
 352  * always converts %7E back to ~, and converting it in this function can
 353  * cause a redirect loop (T105265).
 354  *
 355  * But + is not safe because it's used to indicate a space; &= are only safe in
 356  * paths and not in queries (and we don't distinguish here); ' seems kind of
 357  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 358  * is reserved, we don't care.  So the list we unescape is:
 359  *
 360  * ;:@$!*(),/~
 361  *
 362  * However, IIS7 redirects fail when the url contains a colon (see T24709),
 363  * so no fancy : for IIS7.
 364  *
 365  * %2F in the page titles seems to fatally break for some reason.
 366  *
 367  * @param string $s
 368  * @return string
 369  */
 370 function wfUrlencode( $s ) {
 371         static $needle;
 372
 373         if ( is_null( $s ) ) {
 374                 $needle = null;
 375                 return '';
 376         }
 377
 378         if ( is_null( $needle ) ) {
 379                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 380                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 381                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 382                 ) {
 383                         $needle[] = '%3A';
 384                 }
 385         }
 386
 387         $s = urlencode( $s );
 388         $s = str_ireplace(
 389                 $needle,
 390                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 391                 $s
 392         );
 393
 394         return $s;
 395 }
 396
 397 /**
 398  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 399  * "days=7&limit=100". Options in the first array override options in the second.
 400  * Options set to null or false will not be output.
 401  *
 402  * @param array $array1 ( String|Array )
 403  * @param array|null $array2 ( String|Array )
 404  * @param string $prefix
 405  * @return string
 406  */
 407 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 408         if ( !is_null( $array2 ) ) {
 409                 $array1 = $array1 + $array2;
 410         }
 411
 412         $cgi = '';
 413         foreach ( $array1 as $key => $value ) {
 414                 if ( !is_null( $value ) && $value !== false ) {
 415                         if ( $cgi != '' ) {
 416                                 $cgi .= '&';
 417                         }
 418                         if ( $prefix !== '' ) {
 419                                 $key = $prefix . "[$key]";
 420                         }
 421                         if ( is_array( $value ) ) {
 422                                 $firstTime = true;
 423                                 foreach ( $value as $k => $v ) {
 424                                         $cgi .= $firstTime ? '' : '&';
 425                                         if ( is_array( $v ) ) {
 426                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 427                                         } else {
 428                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 429                                         }
 430                                         $firstTime = false;
 431                                 }
 432                         } else {
 433                                 if ( is_object( $value ) ) {
 434                                         $value = $value->__toString();
 435                                 }
 436                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 437                         }
 438                 }
 439         }
 440         return $cgi;
 441 }
 442
 443 /**
 444  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 445  * its argument and returns the same string in array form.  This allows compatibility
 446  * with legacy functions that accept raw query strings instead of nice
 447  * arrays.  Of course, keys and values are urldecode()d.
 448  *
 449  * @param string $query Query string
 450  * @return string[] Array version of input
 451  */
 452 function wfCgiToArray( $query ) {
 453         if ( isset( $query[0] ) && $query[0] == '?' ) {
 454                 $query = substr( $query, 1 );
 455         }
 456         $bits = explode( '&', $query );
 457         $ret = [];
 458         foreach ( $bits as $bit ) {
 459                 if ( $bit === '' ) {
 460                         continue;
 461                 }
 462                 if ( strpos( $bit, '=' ) === false ) {
 463                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 464                         $key = $bit;
 465                         $value = '';
 466                 } else {
 467                         list( $key, $value ) = explode( '=', $bit );
 468                 }
 469                 $key = urldecode( $key );
 470                 $value = urldecode( $value );
 471                 if ( strpos( $key, '[' ) !== false ) {
 472                         $keys = array_reverse( explode( '[', $key ) );
 473                         $key = array_pop( $keys );
 474                         $temp = $value;
 475                         foreach ( $keys as $k ) {
 476                                 $k = substr( $k, 0, -1 );
 477                                 $temp = [ $k => $temp ];
 478                         }
 479                         if ( isset( $ret[$key] ) ) {
 480                                 $ret[$key] = array_merge( $ret[$key], $temp );
 481                         } else {
 482                                 $ret[$key] = $temp;
 483                         }
 484                 } else {
 485                         $ret[$key] = $value;
 486                 }
 487         }
 488         return $ret;
 489 }
 490
 491 /**
 492  * Append a query string to an existing URL, which may or may not already
 493  * have query string parameters already. If so, they will be combined.
 494  *
 495  * @param string $url
 496  * @param string|string[] $query String or associative array
 497  * @return string
 498  */
 499 function wfAppendQuery( $url, $query ) {
 500         if ( is_array( $query ) ) {
 501                 $query = wfArrayToCgi( $query );
 502         }
 503         if ( $query != '' ) {
 504                 // Remove the fragment, if there is one
 505                 $fragment = false;
 506                 $hashPos = strpos( $url, '#' );
 507                 if ( $hashPos !== false ) {
 508                         $fragment = substr( $url, $hashPos );
 509                         $url = substr( $url, 0, $hashPos );
 510                 }
 511
 512                 // Add parameter
 513                 if ( false === strpos( $url, '?' ) ) {
 514                         $url .= '?';
 515                 } else {
 516                         $url .= '&';
 517                 }
 518                 $url .= $query;
 519
 520                 // Put the fragment back
 521                 if ( $fragment !== false ) {
 522                         $url .= $fragment;
 523                 }
 524         }
 525         return $url;
 526 }
 527
 528 /**
 529  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 530  * is correct.
 531  *
 532  * The meaning of the PROTO_* constants is as follows:
 533  * PROTO_HTTP: Output a URL starting with http://
 534  * PROTO_HTTPS: Output a URL starting with https://
 535  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 536  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 537  *    on which protocol was used for the current incoming request
 538  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 539  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 540  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 541  *
 542  * @todo this won't work with current-path-relative URLs
 543  * like "subdir/foo.html", etc.
 544  *
 545  * @param string $url Either fully-qualified or a local path + query
 546  * @param string $defaultProto One of the PROTO_* constants. Determines the
 547  *    protocol to use if $url or $wgServer is protocol-relative
 548  * @return string Fully-qualified URL, current-path-relative URL or false if
 549  *    no valid URL can be constructed
 550  */
 551 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 552         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 553                 $wgHttpsPort;
 554         if ( $defaultProto === PROTO_CANONICAL ) {
 555                 $serverUrl = $wgCanonicalServer;
 556         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 557                 // Make $wgInternalServer fall back to $wgServer if not set
 558                 $serverUrl = $wgInternalServer;
 559         } else {
 560                 $serverUrl = $wgServer;
 561                 if ( $defaultProto === PROTO_CURRENT ) {
 562                         $defaultProto = $wgRequest->getProtocol() . '://';
 563                 }
 564         }
 565
 566         // Analyze $serverUrl to obtain its protocol
 567         $bits = wfParseUrl( $serverUrl );
 568         $serverHasProto = $bits && $bits['scheme'] != '';
 569
 570         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 571                 if ( $serverHasProto ) {
 572                         $defaultProto = $bits['scheme'] . '://';
 573                 } else {
 574                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 575                         // This really isn't supposed to happen. Fall back to HTTP in this
 576                         // ridiculous case.
 577                         $defaultProto = PROTO_HTTP;
 578                 }
 579         }
 580
 581         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 582
 583         if ( substr( $url, 0, 2 ) == '//' ) {
 584                 $url = $defaultProtoWithoutSlashes . $url;
 585         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 586                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 587                 // otherwise leave it alone.
 588                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 589         }
 590
 591         $bits = wfParseUrl( $url );
 592
 593         // ensure proper port for HTTPS arrives in URL
 594         // https://phabricator.wikimedia.org/T67184
 595         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 596                 $bits['port'] = $wgHttpsPort;
 597         }
 598
 599         if ( $bits && isset( $bits['path'] ) ) {
 600                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 601                 return wfAssembleUrl( $bits );
 602         } elseif ( $bits ) {
 603                 # No path to expand
 604                 return $url;
 605         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 606                 # URL is a relative path
 607                 return wfRemoveDotSegments( $url );
 608         }
 609
 610         # Expanded URL is not valid.
 611         return false;
 612 }
 613
 614 /**
 615  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 616  * if you need to edit part of a URL and put it back together.
 617  *
 618  * This is the basic structure used (brackets contain keys for $urlParts):
 619  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 620  *
 621  * @todo Need to integrate this into wfExpandUrl (see T34168)
 622  *
 623  * @since 1.19
 624  * @param array $urlParts URL parts, as output from wfParseUrl
 625  * @return string URL assembled from its component parts
 626  */
 627 function wfAssembleUrl( $urlParts ) {
 628         $result = '';
 629
 630         if ( isset( $urlParts['delimiter'] ) ) {
 631                 if ( isset( $urlParts['scheme'] ) ) {
 632                         $result .= $urlParts['scheme'];
 633                 }
 634
 635                 $result .= $urlParts['delimiter'];
 636         }
 637
 638         if ( isset( $urlParts['host'] ) ) {
 639                 if ( isset( $urlParts['user'] ) ) {
 640                         $result .= $urlParts['user'];
 641                         if ( isset( $urlParts['pass'] ) ) {
 642                                 $result .= ':' . $urlParts['pass'];
 643                         }
 644                         $result .= '@';
 645                 }
 646
 647                 $result .= $urlParts['host'];
 648
 649                 if ( isset( $urlParts['port'] ) ) {
 650                         $result .= ':' . $urlParts['port'];
 651                 }
 652         }
 653
 654         if ( isset( $urlParts['path'] ) ) {
 655                 $result .= $urlParts['path'];
 656         }
 657
 658         if ( isset( $urlParts['query'] ) ) {
 659                 $result .= '?' . $urlParts['query'];
 660         }
 661
 662         if ( isset( $urlParts['fragment'] ) ) {
 663                 $result .= '#' . $urlParts['fragment'];
 664         }
 665
 666         return $result;
 667 }
 668
 669 /**
 670  * Remove all dot-segments in the provided URL path.  For example,
 671  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 672  * RFC3986 section 5.2.4.
 673  *
 674  * @todo Need to integrate this into wfExpandUrl (see T34168)
 675  *
 676  * @param string $urlPath URL path, potentially containing dot-segments
 677  * @return string URL path with all dot-segments removed
 678  */
 679 function wfRemoveDotSegments( $urlPath ) {
 680         $output = '';
 681         $inputOffset = 0;
 682         $inputLength = strlen( $urlPath );
 683
 684         while ( $inputOffset < $inputLength ) {
 685                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 686                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 687                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 688                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 689                 $trimOutput = false;
 690
 691                 if ( $prefixLengthTwo == './' ) {
 692                         # Step A, remove leading "./"
 693                         $inputOffset += 2;
 694                 } elseif ( $prefixLengthThree == '../' ) {
 695                         # Step A, remove leading "../"
 696                         $inputOffset += 3;
 697                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 698                         # Step B, replace leading "/.$" with "/"
 699                         $inputOffset += 1;
 700                         $urlPath[$inputOffset] = '/';
 701                 } elseif ( $prefixLengthThree == '/./' ) {
 702                         # Step B, replace leading "/./" with "/"
 703                         $inputOffset += 2;
 704                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 705                         # Step C, replace leading "/..$" with "/" and
 706                         # remove last path component in output
 707                         $inputOffset += 2;
 708                         $urlPath[$inputOffset] = '/';
 709                         $trimOutput = true;
 710                 } elseif ( $prefixLengthFour == '/../' ) {
 711                         # Step C, replace leading "/../" with "/" and
 712                         # remove last path component in output
 713                         $inputOffset += 3;
 714                         $trimOutput = true;
 715                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 716                         # Step D, remove "^.$"
 717                         $inputOffset += 1;
 718                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 719                         # Step D, remove "^..$"
 720                         $inputOffset += 2;
 721                 } else {
 722                         # Step E, move leading path segment to output
 723                         if ( $prefixLengthOne == '/' ) {
 724                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 725                         } else {
 726                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 727                         }
 728                         if ( $slashPos === false ) {
 729                                 $output .= substr( $urlPath, $inputOffset );
 730                                 $inputOffset = $inputLength;
 731                         } else {
 732                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 733                                 $inputOffset += $slashPos - $inputOffset;
 734                         }
 735                 }
 736
 737                 if ( $trimOutput ) {
 738                         $slashPos = strrpos( $output, '/' );
 739                         if ( $slashPos === false ) {
 740                                 $output = '';
 741                         } else {
 742                                 $output = substr( $output, 0, $slashPos );
 743                         }
 744                 }
 745         }
 746
 747         return $output;
 748 }
 749
 750 /**
 751  * Returns a regular expression of url protocols
 752  *
 753  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 754  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 755  * @return string
 756  */
 757 function wfUrlProtocols( $includeProtocolRelative = true ) {
 758         global $wgUrlProtocols;
 759
 760         // Cache return values separately based on $includeProtocolRelative
 761         static $withProtRel = null, $withoutProtRel = null;
 762         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 763         if ( !is_null( $cachedValue ) ) {
 764                 return $cachedValue;
 765         }
 766
 767         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 768         // with LocalSettings files from 1.5
 769         if ( is_array( $wgUrlProtocols ) ) {
 770                 $protocols = [];
 771                 foreach ( $wgUrlProtocols as $protocol ) {
 772                         // Filter out '//' if !$includeProtocolRelative
 773                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 774                                 $protocols[] = preg_quote( $protocol, '/' );
 775                         }
 776                 }
 777
 778                 $retval = implode( '|', $protocols );
 779         } else {
 780                 // Ignore $includeProtocolRelative in this case
 781                 // This case exists for pre-1.6 compatibility, and we can safely assume
 782                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 783                 // URLs weren't supported until 1.18
 784                 $retval = $wgUrlProtocols;
 785         }
 786
 787         // Cache return value
 788         if ( $includeProtocolRelative ) {
 789                 $withProtRel = $retval;
 790         } else {
 791                 $withoutProtRel = $retval;
 792         }
 793         return $retval;
 794 }
 795
 796 /**
 797  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 798  * you need a regex that matches all URL protocols but does not match protocol-
 799  * relative URLs
 800  * @return string
 801  */
 802 function wfUrlProtocolsWithoutProtRel() {
 803         return wfUrlProtocols( false );
 804 }
 805
 806 /**
 807  * parse_url() work-alike, but non-broken.  Differences:
 808  *
 809  * 1) Does not raise warnings on bad URLs (just returns false).
 810  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 811  *    protocol-relative URLs) correctly.
 812  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 813  *
 814  * @param string $url A URL to parse
 815  * @return string[]|bool Bits of the URL in an associative array, per PHP docs, false on failure
 816  */
 817 function wfParseUrl( $url ) {
 818         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 819
 820         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 821         // bad that the easiest way to handle them is to just prepend 'http:' and
 822         // strip the protocol out later.
 823         $wasRelative = substr( $url, 0, 2 ) == '//';
 824         if ( $wasRelative ) {
 825                 $url = "http:$url";
 826         }
 827         MediaWiki\suppressWarnings();
 828         $bits = parse_url( $url );
 829         MediaWiki\restoreWarnings();
 830         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 831         // parse_url("%0Ahttp://example.com") == [ 'host' => '%0Ahttp', 'path' => 'example.com' ]
 832         if ( !$bits || !isset( $bits['scheme'] ) ) {
 833                 return false;
 834         }
 835
 836         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 837         $bits['scheme'] = strtolower( $bits['scheme'] );
 838
 839         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 840         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 841                 $bits['delimiter'] = '://';
 842         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 843                 $bits['delimiter'] = ':';
 844                 // parse_url detects for news: and mailto: the host part of an url as path
 845                 // We have to correct this wrong detection
 846                 if ( isset( $bits['path'] ) ) {
 847                         $bits['host'] = $bits['path'];
 848                         $bits['path'] = '';
 849                 }
 850         } else {
 851                 return false;
 852         }
 853
 854         /* Provide an empty host for eg. file:/// urls (see T30627) */
 855         if ( !isset( $bits['host'] ) ) {
 856                 $bits['host'] = '';
 857
 858                 // See T47069
 859                 if ( isset( $bits['path'] ) ) {
 860                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 861                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 862                                 $bits['path'] = '/' . $bits['path'];
 863                         }
 864                 } else {
 865                         $bits['path'] = '';
 866                 }
 867         }
 868
 869         // If the URL was protocol-relative, fix scheme and delimiter
 870         if ( $wasRelative ) {
 871                 $bits['scheme'] = '';
 872                 $bits['delimiter'] = '//';
 873         }
 874         return $bits;
 875 }
 876
 877 /**
 878  * Take a URL, make sure it's expanded to fully qualified, and replace any
 879  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 880  * for more compact display and legibility for local audiences.
 881  *
 882  * @todo handle punycode domains too
 883  *
 884  * @param string $url
 885  * @return string
 886  */
 887 function wfExpandIRI( $url ) {
 888         return preg_replace_callback(
 889                 '/((?:%[89A-F][0-9A-F])+)/i',
 890                 'wfExpandIRI_callback',
 891                 wfExpandUrl( $url )
 892         );
 893 }
 894
 895 /**
 896  * Private callback for wfExpandIRI
 897  * @param array $matches
 898  * @return string
 899  */
 900 function wfExpandIRI_callback( $matches ) {
 901         return urldecode( $matches[1] );
 902 }
 903
 904 /**
 905  * Make URL indexes, appropriate for the el_index field of externallinks.
 906  *
 907  * @param string $url
 908  * @return array
 909  */
 910 function wfMakeUrlIndexes( $url ) {
 911         $bits = wfParseUrl( $url );
 912
 913         // Reverse the labels in the hostname, convert to lower case
 914         // For emails reverse domainpart only
 915         if ( $bits['scheme'] == 'mailto' ) {
 916                 $mailparts = explode( '@', $bits['host'], 2 );
 917                 if ( count( $mailparts ) === 2 ) {
 918                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 919                 } else {
 920                         // No domain specified, don't mangle it
 921                         $domainpart = '';
 922                 }
 923                 $reversedHost = $domainpart . '@' . $mailparts[0];
 924         } else {
 925                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 926         }
 927         // Add an extra dot to the end
 928         // Why? Is it in wrong place in mailto links?
 929         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 930                 $reversedHost .= '.';
 931         }
 932         // Reconstruct the pseudo-URL
 933         $prot = $bits['scheme'];
 934         $index = $prot . $bits['delimiter'] . $reversedHost;
 935         // Leave out user and password. Add the port, path, query and fragment
 936         if ( isset( $bits['port'] ) ) {
 937                 $index .= ':' . $bits['port'];
 938         }
 939         if ( isset( $bits['path'] ) ) {
 940                 $index .= $bits['path'];
 941         } else {
 942                 $index .= '/';
 943         }
 944         if ( isset( $bits['query'] ) ) {
 945                 $index .= '?' . $bits['query'];
 946         }
 947         if ( isset( $bits['fragment'] ) ) {
 948                 $index .= '#' . $bits['fragment'];
 949         }
 950
 951         if ( $prot == '' ) {
 952                 return [ "http:$index", "https:$index" ];
 953         } else {
 954                 return [ $index ];
 955         }
 956 }
 957
 958 /**
 959  * Check whether a given URL has a domain that occurs in a given set of domains
 960  * @param string $url URL
 961  * @param array $domains Array of domains (strings)
 962  * @return bool True if the host part of $url ends in one of the strings in $domains
 963  */
 964 function wfMatchesDomainList( $url, $domains ) {
 965         $bits = wfParseUrl( $url );
 966         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 967                 $host = '.' . $bits['host'];
 968                 foreach ( (array)$domains as $domain ) {
 969                         $domain = '.' . $domain;
 970                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 971                                 return true;
 972                         }
 973                 }
 974         }
 975         return false;
 976 }
 977
 978 /**
 979  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 980  * In normal operation this is a NOP.
 981  *
 982  * Controlling globals:
 983  * $wgDebugLogFile - points to the log file
 984  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 985  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 986  *
 987  * @since 1.25 support for additional context data
 988  *
 989  * @param string $text
 990  * @param string|bool $dest Destination of the message:
 991  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 992  *     - 'private': excluded from HTML output
 993  *   For backward compatibility, it can also take a boolean:
 994  *     - true: same as 'all'
 995  *     - false: same as 'private'
 996  * @param array $context Additional logging context data
 997  */
 998 function wfDebug( $text, $dest = 'all', array $context = [] ) {
 999         global $wgDebugRawPage, $wgDebugLogPrefix;
1000         global $wgDebugTimestamps, $wgRequestTime;
1001
1002         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1003                 return;
1004         }
1005
1006         $text = trim( $text );
1007
1008         if ( $wgDebugTimestamps ) {
1009                 $context['seconds_elapsed'] = sprintf(
1010                         '%6.4f',
1011                         microtime( true ) - $wgRequestTime
1012                 );
1013                 $context['memory_used'] = sprintf(
1014                         '%5.1fM',
1015                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1016                 );
1017         }
1018
1019         if ( $wgDebugLogPrefix !== '' ) {
1020                 $context['prefix'] = $wgDebugLogPrefix;
1021         }
1022         $context['private'] = ( $dest === false || $dest === 'private' );
1023
1024         $logger = LoggerFactory::getInstance( 'wfDebug' );
1025         $logger->debug( $text, $context );
1026 }
1027
1028 /**
1029  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1030  * @return bool
1031  */
1032 function wfIsDebugRawPage() {
1033         static $cache;
1034         if ( $cache !== null ) {
1035                 return $cache;
1036         }
1037         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1038         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1039                 || (
1040                         isset( $_SERVER['SCRIPT_NAME'] )
1041                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1042                 )
1043         ) {
1044                 $cache = true;
1045         } else {
1046                 $cache = false;
1047         }
1048         return $cache;
1049 }
1050
1051 /**
1052  * Send a line giving PHP memory usage.
1053  *
1054  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1055  */
1056 function wfDebugMem( $exact = false ) {
1057         $mem = memory_get_usage();
1058         if ( !$exact ) {
1059                 $mem = floor( $mem / 1024 ) . ' KiB';
1060         } else {
1061                 $mem .= ' B';
1062         }
1063         wfDebug( "Memory usage: $mem\n" );
1064 }
1065
1066 /**
1067  * Send a line to a supplementary debug log file, if configured, or main debug
1068  * log if not.
1069  *
1070  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1071  * a string filename or an associative array mapping 'destination' to the
1072  * desired filename. The associative array may also contain a 'sample' key
1073  * with an integer value, specifying a sampling factor. Sampled log events
1074  * will be emitted with a 1 in N random chance.
1075  *
1076  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1077  * @since 1.25 support for additional context data
1078  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1079  *
1080  * @param string $logGroup
1081  * @param string $text
1082  * @param string|bool $dest Destination of the message:
1083  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1084  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1085  *       discarded otherwise
1086  *   For backward compatibility, it can also take a boolean:
1087  *     - true: same as 'all'
1088  *     - false: same as 'private'
1089  * @param array $context Additional logging context data
1090  */
1091 function wfDebugLog(
1092         $logGroup, $text, $dest = 'all', array $context = []
1093 ) {
1094         $text = trim( $text );
1095
1096         $logger = LoggerFactory::getInstance( $logGroup );
1097         $context['private'] = ( $dest === false || $dest === 'private' );
1098         $logger->info( $text, $context );
1099 }
1100
1101 /**
1102  * Log for database errors
1103  *
1104  * @since 1.25 support for additional context data
1105  *
1106  * @param string $text Database error message.
1107  * @param array $context Additional logging context data
1108  */
1109 function wfLogDBError( $text, array $context = [] ) {
1110         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1111         $logger->error( trim( $text ), $context );
1112 }
1113
1114 /**
1115  * Throws a warning that $function is deprecated
1116  *
1117  * @param string $function
1118  * @param string|bool $version Version of MediaWiki that the function
1119  *    was deprecated in (Added in 1.19).
1120  * @param string|bool $component Added in 1.19.
1121  * @param int $callerOffset How far up the call stack is the original
1122  *    caller. 2 = function that called the function that called
1123  *    wfDeprecated (Added in 1.20)
1124  *
1125  * @return null
1126  */
1127 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1128         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1129 }
1130
1131 /**
1132  * Send a warning either to the debug log or in a PHP error depending on
1133  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1134  *
1135  * @param string $msg Message to send
1136  * @param int $callerOffset Number of items to go back in the backtrace to
1137  *        find the correct caller (1 = function calling wfWarn, ...)
1138  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1139  *        only used when $wgDevelopmentWarnings is true
1140  */
1141 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1142         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1143 }
1144
1145 /**
1146  * Send a warning as a PHP error and the debug log. This is intended for logging
1147  * warnings in production. For logging development warnings, use WfWarn instead.
1148  *
1149  * @param string $msg Message to send
1150  * @param int $callerOffset Number of items to go back in the backtrace to
1151  *        find the correct caller (1 = function calling wfLogWarning, ...)
1152  * @param int $level PHP error level; defaults to E_USER_WARNING
1153  */
1154 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1155         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1156 }
1157
1158 /**
1159  * Log to a file without getting "file size exceeded" signals.
1160  *
1161  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1162  * send lines to the specified port, prefixed by the specified prefix and a space.
1163  * @since 1.25 support for additional context data
1164  *
1165  * @param string $text
1166  * @param string $file Filename
1167  * @param array $context Additional logging context data
1168  * @throws MWException
1169  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1170  */
1171 function wfErrorLog( $text, $file, array $context = [] ) {
1172         wfDeprecated( __METHOD__, '1.25' );
1173         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1174         $context['destination'] = $file;
1175         $logger->info( trim( $text ), $context );
1176 }
1177
1178 /**
1179  * @todo document
1180  */
1181 function wfLogProfilingData() {
1182         global $wgDebugLogGroups, $wgDebugRawPage;
1183
1184         $context = RequestContext::getMain();
1185         $request = $context->getRequest();
1186
1187         $profiler = Profiler::instance();
1188         $profiler->setContext( $context );
1189         $profiler->logData();
1190
1191         $config = $context->getConfig();
1192         if ( $config->get( 'StatsdServer' ) ) {
1193                 try {
1194                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1195                         $statsdHost = $statsdServer[0];
1196                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1197                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1198                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1199                         $statsdClient->setSamplingRates( $config->get( 'StatsdSamplingRates' ) );
1200                         $statsdClient->send( $context->getStats()->getBuffer() );
1201                 } catch ( Exception $ex ) {
1202                         MWExceptionHandler::logException( $ex );
1203                 }
1204         }
1205
1206         # Profiling must actually be enabled...
1207         if ( $profiler instanceof ProfilerStub ) {
1208                 return;
1209         }
1210
1211         if ( isset( $wgDebugLogGroups['profileoutput'] )
1212                 && $wgDebugLogGroups['profileoutput'] === false
1213         ) {
1214                 // Explicitly disabled
1215                 return;
1216         }
1217         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1218                 return;
1219         }
1220
1221         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1222         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1223                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1224         }
1225         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1226                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1227         }
1228         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1229                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1230         }
1231         if ( isset( $ctx['forwarded_for'] ) ||
1232                 isset( $ctx['client_ip'] ) ||
1233                 isset( $ctx['from'] ) ) {
1234                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1235         }
1236
1237         // Don't load $wgUser at this late stage just for statistics purposes
1238         // @todo FIXME: We can detect some anons even if it is not loaded.
1239         // See User::getId()
1240         $user = $context->getUser();
1241         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1242
1243         // Command line script uses a FauxRequest object which does not have
1244         // any knowledge about an URL and throw an exception instead.
1245         try {
1246                 $ctx['url'] = urldecode( $request->getRequestURL() );
1247         } catch ( Exception $ignored ) {
1248                 // no-op
1249         }
1250
1251         $ctx['output'] = $profiler->getOutput();
1252
1253         $log = LoggerFactory::getInstance( 'profileoutput' );
1254         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1255 }
1256
1257 /**
1258  * Increment a statistics counter
1259  *
1260  * @param string $key
1261  * @param int $count
1262  * @return void
1263  */
1264 function wfIncrStats( $key, $count = 1 ) {
1265         $stats = RequestContext::getMain()->getStats();
1266         $stats->updateCount( $key, $count );
1267 }
1268
1269 /**
1270  * Check whether the wiki is in read-only mode.
1271  *
1272  * @return bool
1273  */
1274 function wfReadOnly() {
1275         return wfReadOnlyReason() !== false;
1276 }
1277
1278 /**
1279  * Check if the site is in read-only mode and return the message if so
1280  *
1281  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1282  * for replica DB lag. This may result in DB connection being made.
1283  *
1284  * @return string|bool String when in read-only mode; false otherwise
1285  */
1286 function wfReadOnlyReason() {
1287         $readOnly = wfConfiguredReadOnlyReason();
1288         if ( $readOnly !== false ) {
1289                 return $readOnly;
1290         }
1291
1292         static $lbReadOnly = null;
1293         if ( $lbReadOnly === null ) {
1294                 // Callers use this method to be aware that data presented to a user
1295                 // may be very stale and thus allowing submissions can be problematic.
1296                 $lbReadOnly = wfGetLB()->getReadOnlyReason();
1297         }
1298
1299         return $lbReadOnly;
1300 }
1301
1302 /**
1303  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1304  *
1305  * @return string|bool String when in read-only mode; false otherwise
1306  * @since 1.27
1307  */
1308 function wfConfiguredReadOnlyReason() {
1309         global $wgReadOnly, $wgReadOnlyFile;
1310
1311         if ( $wgReadOnly === null ) {
1312                 // Set $wgReadOnly for faster access next time
1313                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1314                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1315                 } else {
1316                         $wgReadOnly = false;
1317                 }
1318         }
1319
1320         return $wgReadOnly;
1321 }
1322
1323 /**
1324  * Return a Language object from $langcode
1325  *
1326  * @param Language|string|bool $langcode Either:
1327  *                  - a Language object
1328  *                  - code of the language to get the message for, if it is
1329  *                    a valid code create a language for that language, if
1330  *                    it is a string but not a valid code then make a basic
1331  *                    language object
1332  *                  - a boolean: if it's false then use the global object for
1333  *                    the current user's language (as a fallback for the old parameter
1334  *                    functionality), or if it is true then use global object
1335  *                    for the wiki's content language.
1336  * @return Language
1337  */
1338 function wfGetLangObj( $langcode = false ) {
1339         # Identify which language to get or create a language object for.
1340         # Using is_object here due to Stub objects.
1341         if ( is_object( $langcode ) ) {
1342                 # Great, we already have the object (hopefully)!
1343                 return $langcode;
1344         }
1345
1346         global $wgContLang, $wgLanguageCode;
1347         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1348                 # $langcode is the language code of the wikis content language object.
1349                 # or it is a boolean and value is true
1350                 return $wgContLang;
1351         }
1352
1353         global $wgLang;
1354         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1355                 # $langcode is the language code of user language object.
1356                 # or it was a boolean and value is false
1357                 return $wgLang;
1358         }
1359
1360         $validCodes = array_keys( Language::fetchLanguageNames() );
1361         if ( in_array( $langcode, $validCodes ) ) {
1362                 # $langcode corresponds to a valid language.
1363                 return Language::factory( $langcode );
1364         }
1365
1366         # $langcode is a string, but not a valid language code; use content language.
1367         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1368         return $wgContLang;
1369 }
1370
1371 /**
1372  * This is the function for getting translated interface messages.
1373  *
1374  * @see Message class for documentation how to use them.
1375  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1376  *
1377  * This function replaces all old wfMsg* functions.
1378  *
1379  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1380  * @param mixed $params,... Normal message parameters
1381  * @return Message
1382  *
1383  * @since 1.17
1384  *
1385  * @see Message::__construct
1386  */
1387 function wfMessage( $key /*...*/ ) {
1388         $params = func_get_args();
1389         array_shift( $params );
1390         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1391                 $params = $params[0];
1392         }
1393         return new Message( $key, $params );
1394 }
1395
1396 /**
1397  * This function accepts multiple message keys and returns a message instance
1398  * for the first message which is non-empty. If all messages are empty then an
1399  * instance of the first message key is returned.
1400  *
1401  * @param string|string[] $keys,... Message keys
1402  * @return Message
1403  *
1404  * @since 1.18
1405  *
1406  * @see Message::newFallbackSequence
1407  */
1408 function wfMessageFallback( /*...*/ ) {
1409         $args = func_get_args();
1410         return call_user_func_array( 'Message::newFallbackSequence', $args );
1411 }
1412
1413 /**
1414  * Replace message parameter keys on the given formatted output.
1415  *
1416  * @param string $message
1417  * @param array $args
1418  * @return string
1419  * @private
1420  */
1421 function wfMsgReplaceArgs( $message, $args ) {
1422         # Fix windows line-endings
1423         # Some messages are split with explode("\n", $msg)
1424         $message = str_replace( "\r", '', $message );
1425
1426         // Replace arguments
1427         if ( is_array( $args ) && $args ) {
1428                 if ( is_array( $args[0] ) ) {
1429                         $args = array_values( $args[0] );
1430                 }
1431                 $replacementKeys = [];
1432                 foreach ( $args as $n => $param ) {
1433                         $replacementKeys['$' . ( $n + 1 )] = $param;
1434                 }
1435                 $message = strtr( $message, $replacementKeys );
1436         }
1437
1438         return $message;
1439 }
1440
1441 /**
1442  * Fetch server name for use in error reporting etc.
1443  * Use real server name if available, so we know which machine
1444  * in a server farm generated the current page.
1445  *
1446  * @return string
1447  */
1448 function wfHostname() {
1449         static $host;
1450         if ( is_null( $host ) ) {
1451
1452                 # Hostname overriding
1453                 global $wgOverrideHostname;
1454                 if ( $wgOverrideHostname !== false ) {
1455                         # Set static and skip any detection
1456                         $host = $wgOverrideHostname;
1457                         return $host;
1458                 }
1459
1460                 if ( function_exists( 'posix_uname' ) ) {
1461                         // This function not present on Windows
1462                         $uname = posix_uname();
1463                 } else {
1464                         $uname = false;
1465                 }
1466                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1467                         $host = $uname['nodename'];
1468                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1469                         # Windows computer name
1470                         $host = getenv( 'COMPUTERNAME' );
1471                 } else {
1472                         # This may be a virtual server.
1473                         $host = $_SERVER['SERVER_NAME'];
1474                 }
1475         }
1476         return $host;
1477 }
1478
1479 /**
1480  * Returns a script tag that stores the amount of time it took MediaWiki to
1481  * handle the request in milliseconds as 'wgBackendResponseTime'.
1482  *
1483  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1484  * hostname of the server handling the request.
1485  *
1486  * @return string
1487  */
1488 function wfReportTime() {
1489         global $wgRequestTime, $wgShowHostnames;
1490
1491         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1492         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1493         if ( $wgShowHostnames ) {
1494                 $reportVars['wgHostname'] = wfHostname();
1495         }
1496         return Skin::makeVariablesScript( $reportVars );
1497 }
1498
1499 /**
1500  * Safety wrapper for debug_backtrace().
1501  *
1502  * Will return an empty array if debug_backtrace is disabled, otherwise
1503  * the output from debug_backtrace() (trimmed).
1504  *
1505  * @param int $limit This parameter can be used to limit the number of stack frames returned
1506  *
1507  * @return array Array of backtrace information
1508  */
1509 function wfDebugBacktrace( $limit = 0 ) {
1510         static $disabled = null;
1511
1512         if ( is_null( $disabled ) ) {
1513                 $disabled = !function_exists( 'debug_backtrace' );
1514                 if ( $disabled ) {
1515                         wfDebug( "debug_backtrace() is disabled\n" );
1516                 }
1517         }
1518         if ( $disabled ) {
1519                 return [];
1520         }
1521
1522         if ( $limit ) {
1523                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1524         } else {
1525                 return array_slice( debug_backtrace(), 1 );
1526         }
1527 }
1528
1529 /**
1530  * Get a debug backtrace as a string
1531  *
1532  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1533  *   Defaults to $wgCommandLineMode if unset.
1534  * @return string
1535  * @since 1.25 Supports $raw parameter.
1536  */
1537 function wfBacktrace( $raw = null ) {
1538         global $wgCommandLineMode;
1539
1540         if ( $raw === null ) {
1541                 $raw = $wgCommandLineMode;
1542         }
1543
1544         if ( $raw ) {
1545                 $frameFormat = "%s line %s calls %s()\n";
1546                 $traceFormat = "%s";
1547         } else {
1548                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1549                 $traceFormat = "<ul>\n%s</ul>\n";
1550         }
1551
1552         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1553                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1554                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1555                 $call = $frame['function'];
1556                 if ( !empty( $frame['class'] ) ) {
1557                         $call = $frame['class'] . $frame['type'] . $call;
1558                 }
1559                 return sprintf( $frameFormat, $file, $line, $call );
1560         }, wfDebugBacktrace() );
1561
1562         return sprintf( $traceFormat, implode( '', $frames ) );
1563 }
1564
1565 /**
1566  * Get the name of the function which called this function
1567  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1568  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1569  * wfGetCaller( 3 ) is the parent of that.
1570  *
1571  * @param int $level
1572  * @return string
1573  */
1574 function wfGetCaller( $level = 2 ) {
1575         $backtrace = wfDebugBacktrace( $level + 1 );
1576         if ( isset( $backtrace[$level] ) ) {
1577                 return wfFormatStackFrame( $backtrace[$level] );
1578         } else {
1579                 return 'unknown';
1580         }
1581 }
1582
1583 /**
1584  * Return a string consisting of callers in the stack. Useful sometimes
1585  * for profiling specific points.
1586  *
1587  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1588  * @return string
1589  */
1590 function wfGetAllCallers( $limit = 3 ) {
1591         $trace = array_reverse( wfDebugBacktrace() );
1592         if ( !$limit || $limit > count( $trace ) - 1 ) {
1593                 $limit = count( $trace ) - 1;
1594         }
1595         $trace = array_slice( $trace, -$limit - 1, $limit );
1596         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1597 }
1598
1599 /**
1600  * Return a string representation of frame
1601  *
1602  * @param array $frame
1603  * @return string
1604  */
1605 function wfFormatStackFrame( $frame ) {
1606         if ( !isset( $frame['function'] ) ) {
1607                 return 'NO_FUNCTION_GIVEN';
1608         }
1609         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1610                 $frame['class'] . $frame['type'] . $frame['function'] :
1611                 $frame['function'];
1612 }
1613
1614 /* Some generic result counters, pulled out of SearchEngine */
1615
1616 /**
1617  * @todo document
1618  *
1619  * @param int $offset
1620  * @param int $limit
1621  * @return string
1622  */
1623 function wfShowingResults( $offset, $limit ) {
1624         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1625 }
1626
1627 /**
1628  * Whether the client accept gzip encoding
1629  *
1630  * Uses the Accept-Encoding header to check if the client supports gzip encoding.
1631  * Use this when considering to send a gzip-encoded response to the client.
1632  *
1633  * @param bool $force Forces another check even if we already have a cached result.
1634  * @return bool
1635  */
1636 function wfClientAcceptsGzip( $force = false ) {
1637         static $result = null;
1638         if ( $result === null || $force ) {
1639                 $result = false;
1640                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1641                         # @todo FIXME: We may want to blacklist some broken browsers
1642                         $m = [];
1643                         if ( preg_match(
1644                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1645                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1646                                         $m
1647                                 )
1648                         ) {
1649                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1650                                         $result = false;
1651                                         return $result;
1652                                 }
1653                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1654                                 $result = true;
1655                         }
1656                 }
1657         }
1658         return $result;
1659 }
1660
1661 /**
1662  * Escapes the given text so that it may be output using addWikiText()
1663  * without any linking, formatting, etc. making its way through. This
1664  * is achieved by substituting certain characters with HTML entities.
1665  * As required by the callers, "<nowiki>" is not used.
1666  *
1667  * @param string $text Text to be escaped
1668  * @return string
1669  */
1670 function wfEscapeWikiText( $text ) {
1671         global $wgEnableMagicLinks;
1672         static $repl = null, $repl2 = null;
1673         if ( $repl === null || defined( 'MW_PARSER_TEST' ) || defined( 'MW_PHPUNIT_TEST' ) ) {
1674                 // Tests depend upon being able to change $wgEnableMagicLinks, so don't cache
1675                 // in those situations
1676                 $repl = [
1677                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1678                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1679                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1680                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1681                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1682                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1683                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1684                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1685                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1686                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1687                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1688                         '__' => '_&#95;', '://' => '&#58;//',
1689                 ];
1690
1691                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1692                 // We have to catch everything "\s" matches in PCRE
1693                 foreach ( $magicLinks as $magic ) {
1694                         $repl["$magic "] = "$magic&#32;";
1695                         $repl["$magic\t"] = "$magic&#9;";
1696                         $repl["$magic\r"] = "$magic&#13;";
1697                         $repl["$magic\n"] = "$magic&#10;";
1698                         $repl["$magic\f"] = "$magic&#12;";
1699                 }
1700
1701                 // And handle protocols that don't use "://"
1702                 global $wgUrlProtocols;
1703                 $repl2 = [];
1704                 foreach ( $wgUrlProtocols as $prot ) {
1705                         if ( substr( $prot, -1 ) === ':' ) {
1706                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1707                         }
1708                 }
1709                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1710         }
1711         $text = substr( strtr( "\n$text", $repl ), 1 );
1712         $text = preg_replace( $repl2, '$1&#58;', $text );
1713         return $text;
1714 }
1715
1716 /**
1717  * Sets dest to source and returns the original value of dest
1718  * If source is NULL, it just returns the value, it doesn't set the variable
1719  * If force is true, it will set the value even if source is NULL
1720  *
1721  * @param mixed $dest
1722  * @param mixed $source
1723  * @param bool $force
1724  * @return mixed
1725  */
1726 function wfSetVar( &$dest, $source, $force = false ) {
1727         $temp = $dest;
1728         if ( !is_null( $source ) || $force ) {
1729                 $dest = $source;
1730         }
1731         return $temp;
1732 }
1733
1734 /**
1735  * As for wfSetVar except setting a bit
1736  *
1737  * @param int $dest
1738  * @param int $bit
1739  * @param bool $state
1740  *
1741  * @return bool
1742  */
1743 function wfSetBit( &$dest, $bit, $state = true ) {
1744         $temp = (bool)( $dest & $bit );
1745         if ( !is_null( $state ) ) {
1746                 if ( $state ) {
1747                         $dest |= $bit;
1748                 } else {
1749                         $dest &= ~$bit;
1750                 }
1751         }
1752         return $temp;
1753 }
1754
1755 /**
1756  * A wrapper around the PHP function var_export().
1757  * Either print it or add it to the regular output ($wgOut).
1758  *
1759  * @param mixed $var A PHP variable to dump.
1760  */
1761 function wfVarDump( $var ) {
1762         global $wgOut;
1763         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1764         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1765                 print $s;
1766         } else {
1767                 $wgOut->addHTML( $s );
1768         }
1769 }
1770
1771 /**
1772  * Provide a simple HTTP error.
1773  *
1774  * @param int|string $code
1775  * @param string $label
1776  * @param string $desc
1777  */
1778 function wfHttpError( $code, $label, $desc ) {
1779         global $wgOut;
1780         HttpStatus::header( $code );
1781         if ( $wgOut ) {
1782                 $wgOut->disable();
1783                 $wgOut->sendCacheControl();
1784         }
1785
1786         header( 'Content-type: text/html; charset=utf-8' );
1787         print '<!DOCTYPE html>' .
1788                 '<html><head><title>' .
1789                 htmlspecialchars( $label ) .
1790                 '</title></head><body><h1>' .
1791                 htmlspecialchars( $label ) .
1792                 '</h1><p>' .
1793                 nl2br( htmlspecialchars( $desc ) ) .
1794                 "</p></body></html>\n";
1795 }
1796
1797 /**
1798  * Clear away any user-level output buffers, discarding contents.
1799  *
1800  * Suitable for 'starting afresh', for instance when streaming
1801  * relatively large amounts of data without buffering, or wanting to
1802  * output image files without ob_gzhandler's compression.
1803  *
1804  * The optional $resetGzipEncoding parameter controls suppression of
1805  * the Content-Encoding header sent by ob_gzhandler; by default it
1806  * is left. See comments for wfClearOutputBuffers() for why it would
1807  * be used.
1808  *
1809  * Note that some PHP configuration options may add output buffer
1810  * layers which cannot be removed; these are left in place.
1811  *
1812  * @param bool $resetGzipEncoding
1813  */
1814 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1815         if ( $resetGzipEncoding ) {
1816                 // Suppress Content-Encoding and Content-Length
1817                 // headers from 1.10+s wfOutputHandler
1818                 global $wgDisableOutputCompression;
1819                 $wgDisableOutputCompression = true;
1820         }
1821         while ( $status = ob_get_status() ) {
1822                 if ( isset( $status['flags'] ) ) {
1823                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1824                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1825                 } elseif ( isset( $status['del'] ) ) {
1826                         $deleteable = $status['del'];
1827                 } else {
1828                         // Guess that any PHP-internal setting can't be removed.
1829                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1830                 }
1831                 if ( !$deleteable ) {
1832                         // Give up, and hope the result doesn't break
1833                         // output behavior.
1834                         break;
1835                 }
1836                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1837                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1838                         break;
1839                 }
1840                 if ( !ob_end_clean() ) {
1841                         // Could not remove output buffer handler; abort now
1842                         // to avoid getting in some kind of infinite loop.
1843                         break;
1844                 }
1845                 if ( $resetGzipEncoding ) {
1846                         if ( $status['name'] == 'ob_gzhandler' ) {
1847                                 // Reset the 'Content-Encoding' field set by this handler
1848                                 // so we can start fresh.
1849                                 header_remove( 'Content-Encoding' );
1850                                 break;
1851                         }
1852                 }
1853         }
1854 }
1855
1856 /**
1857  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1858  *
1859  * Clear away output buffers, but keep the Content-Encoding header
1860  * produced by ob_gzhandler, if any.
1861  *
1862  * This should be used for HTTP 304 responses, where you need to
1863  * preserve the Content-Encoding header of the real result, but
1864  * also need to suppress the output of ob_gzhandler to keep to spec
1865  * and avoid breaking Firefox in rare cases where the headers and
1866  * body are broken over two packets.
1867  */
1868 function wfClearOutputBuffers() {
1869         wfResetOutputBuffers( false );
1870 }
1871
1872 /**
1873  * Converts an Accept-* header into an array mapping string values to quality
1874  * factors
1875  *
1876  * @param string $accept
1877  * @param string $def Default
1878  * @return float[] Associative array of string => float pairs
1879  */
1880 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1881         # No arg means accept anything (per HTTP spec)
1882         if ( !$accept ) {
1883                 return [ $def => 1.0 ];
1884         }
1885
1886         $prefs = [];
1887
1888         $parts = explode( ',', $accept );
1889
1890         foreach ( $parts as $part ) {
1891                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1892                 $values = explode( ';', trim( $part ) );
1893                 $match = [];
1894                 if ( count( $values ) == 1 ) {
1895                         $prefs[$values[0]] = 1.0;
1896                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1897                         $prefs[$values[0]] = floatval( $match[1] );
1898                 }
1899         }
1900
1901         return $prefs;
1902 }
1903
1904 /**
1905  * Checks if a given MIME type matches any of the keys in the given
1906  * array. Basic wildcards are accepted in the array keys.
1907  *
1908  * Returns the matching MIME type (or wildcard) if a match, otherwise
1909  * NULL if no match.
1910  *
1911  * @param string $type
1912  * @param array $avail
1913  * @return string
1914  * @private
1915  */
1916 function mimeTypeMatch( $type, $avail ) {
1917         if ( array_key_exists( $type, $avail ) ) {
1918                 return $type;
1919         } else {
1920                 $mainType = explode( '/', $type )[0];
1921                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1922                         return "$mainType/*";
1923                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1924                         return '*/*';
1925                 } else {
1926                         return null;
1927                 }
1928         }
1929 }
1930
1931 /**
1932  * Returns the 'best' match between a client's requested internet media types
1933  * and the server's list of available types. Each list should be an associative
1934  * array of type to preference (preference is a float between 0.0 and 1.0).
1935  * Wildcards in the types are acceptable.
1936  *
1937  * @param array $cprefs Client's acceptable type list
1938  * @param array $sprefs Server's offered types
1939  * @return string
1940  *
1941  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1942  * XXX: generalize to negotiate other stuff
1943  */
1944 function wfNegotiateType( $cprefs, $sprefs ) {
1945         $combine = [];
1946
1947         foreach ( array_keys( $sprefs ) as $type ) {
1948                 $subType = explode( '/', $type )[1];
1949                 if ( $subType != '*' ) {
1950                         $ckey = mimeTypeMatch( $type, $cprefs );
1951                         if ( $ckey ) {
1952                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1953                         }
1954                 }
1955         }
1956
1957         foreach ( array_keys( $cprefs ) as $type ) {
1958                 $subType = explode( '/', $type )[1];
1959                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1960                         $skey = mimeTypeMatch( $type, $sprefs );
1961                         if ( $skey ) {
1962                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1963                         }
1964                 }
1965         }
1966
1967         $bestq = 0;
1968         $besttype = null;
1969
1970         foreach ( array_keys( $combine ) as $type ) {
1971                 if ( $combine[$type] > $bestq ) {
1972                         $besttype = $type;
1973                         $bestq = $combine[$type];
1974                 }
1975         }
1976
1977         return $besttype;
1978 }
1979
1980 /**
1981  * Reference-counted warning suppression
1982  *
1983  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
1984  * @param bool $end
1985  */
1986 function wfSuppressWarnings( $end = false ) {
1987         MediaWiki\suppressWarnings( $end );
1988 }
1989
1990 /**
1991  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
1992  * Restore error level to previous value
1993  */
1994 function wfRestoreWarnings() {
1995         MediaWiki\suppressWarnings( true );
1996 }
1997
1998 # Autodetect, convert and provide timestamps of various types
1999
2000 require_once __DIR__ . '/libs/time/defines.php';
2001
2002 /**
2003  * Get a timestamp string in one of various formats
2004  *
2005  * @param mixed $outputtype A timestamp in one of the supported formats, the
2006  *   function will autodetect which format is supplied and act accordingly.
2007  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2008  * @return string|bool String / false The same date in the format specified in $outputtype or false
2009  */
2010 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2011         $ret = MWTimestamp::convert( $outputtype, $ts );
2012         if ( $ret === false ) {
2013                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2014         }
2015         return $ret;
2016 }
2017
2018 /**
2019  * Return a formatted timestamp, or null if input is null.
2020  * For dealing with nullable timestamp columns in the database.
2021  *
2022  * @param int $outputtype
2023  * @param string $ts
2024  * @return string
2025  */
2026 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2027         if ( is_null( $ts ) ) {
2028                 return null;
2029         } else {
2030                 return wfTimestamp( $outputtype, $ts );
2031         }
2032 }
2033
2034 /**
2035  * Convenience function; returns MediaWiki timestamp for the present time.
2036  *
2037  * @return string
2038  */
2039 function wfTimestampNow() {
2040         # return NOW
2041         return MWTimestamp::now( TS_MW );
2042 }
2043
2044 /**
2045  * Check if the operating system is Windows
2046  *
2047  * @return bool True if it's Windows, false otherwise.
2048  */
2049 function wfIsWindows() {
2050         static $isWindows = null;
2051         if ( $isWindows === null ) {
2052                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2053         }
2054         return $isWindows;
2055 }
2056
2057 /**
2058  * Check if we are running under HHVM
2059  *
2060  * @return bool
2061  */
2062 function wfIsHHVM() {
2063         return defined( 'HHVM_VERSION' );
2064 }
2065
2066 /**
2067  * Tries to get the system directory for temporary files. First
2068  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2069  * environment variables are then checked in sequence, then
2070  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2071  *
2072  * NOTE: When possible, use instead the tmpfile() function to create
2073  * temporary files to avoid race conditions on file creation, etc.
2074  *
2075  * @return string
2076  */
2077 function wfTempDir() {
2078         global $wgTmpDirectory;
2079
2080         if ( $wgTmpDirectory !== false ) {
2081                 return $wgTmpDirectory;
2082         }
2083
2084         return TempFSFile::getUsableTempDirectory();
2085 }
2086
2087 /**
2088  * Make directory, and make all parent directories if they don't exist
2089  *
2090  * @param string $dir Full path to directory to create
2091  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2092  * @param string $caller Optional caller param for debugging.
2093  * @throws MWException
2094  * @return bool
2095  */
2096 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2097         global $wgDirectoryMode;
2098
2099         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2100                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2101         }
2102
2103         if ( !is_null( $caller ) ) {
2104                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2105         }
2106
2107         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2108                 return true;
2109         }
2110
2111         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
2112
2113         if ( is_null( $mode ) ) {
2114                 $mode = $wgDirectoryMode;
2115         }
2116
2117         // Turn off the normal warning, we're doing our own below
2118         MediaWiki\suppressWarnings();
2119         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2120         MediaWiki\restoreWarnings();
2121
2122         if ( !$ok ) {
2123                 // directory may have been created on another request since we last checked
2124                 if ( is_dir( $dir ) ) {
2125                         return true;
2126                 }
2127
2128                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2129                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2130         }
2131         return $ok;
2132 }
2133
2134 /**
2135  * Remove a directory and all its content.
2136  * Does not hide error.
2137  * @param string $dir
2138  */
2139 function wfRecursiveRemoveDir( $dir ) {
2140         wfDebug( __FUNCTION__ . "( $dir )\n" );
2141         // taken from https://secure.php.net/manual/en/function.rmdir.php#98622
2142         if ( is_dir( $dir ) ) {
2143                 $objects = scandir( $dir );
2144                 foreach ( $objects as $object ) {
2145                         if ( $object != "." && $object != ".." ) {
2146                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2147                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2148                                 } else {
2149                                         unlink( $dir . '/' . $object );
2150                                 }
2151                         }
2152                 }
2153                 reset( $objects );
2154                 rmdir( $dir );
2155         }
2156 }
2157
2158 /**
2159  * @param int $nr The number to format
2160  * @param int $acc The number of digits after the decimal point, default 2
2161  * @param bool $round Whether or not to round the value, default true
2162  * @return string
2163  */
2164 function wfPercent( $nr, $acc = 2, $round = true ) {
2165         $ret = sprintf( "%.${acc}f", $nr );
2166         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2167 }
2168
2169 /**
2170  * Safety wrapper around ini_get() for boolean settings.
2171  * The values returned from ini_get() are pre-normalized for settings
2172  * set via php.ini or php_flag/php_admin_flag... but *not*
2173  * for those set via php_value/php_admin_value.
2174  *
2175  * It's fairly common for people to use php_value instead of php_flag,
2176  * which can leave you with an 'off' setting giving a false positive
2177  * for code that just takes the ini_get() return value as a boolean.
2178  *
2179  * To make things extra interesting, setting via php_value accepts
2180  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2181  * Unrecognized values go false... again opposite PHP's own coercion
2182  * from string to bool.
2183  *
2184  * Luckily, 'properly' set settings will always come back as '0' or '1',
2185  * so we only have to worry about them and the 'improper' settings.
2186  *
2187  * I frickin' hate PHP... :P
2188  *
2189  * @param string $setting
2190  * @return bool
2191  */
2192 function wfIniGetBool( $setting ) {
2193         $val = strtolower( ini_get( $setting ) );
2194         // 'on' and 'true' can't have whitespace around them, but '1' can.
2195         return $val == 'on'
2196                 || $val == 'true'
2197                 || $val == 'yes'
2198                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2199 }
2200
2201 /**
2202  * Version of escapeshellarg() that works better on Windows.
2203  *
2204  * Originally, this fixed the incorrect use of single quotes on Windows
2205  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2206  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2207  *
2208  * @param string ... strings to escape and glue together, or a single array of strings parameter
2209  * @return string
2210  */
2211 function wfEscapeShellArg( /*...*/ ) {
2212         wfInitShellLocale();
2213
2214         $args = func_get_args();
2215         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2216                 // If only one argument has been passed, and that argument is an array,
2217                 // treat it as a list of arguments
2218                 $args = reset( $args );
2219         }
2220
2221         $first = true;
2222         $retVal = '';
2223         foreach ( $args as $arg ) {
2224                 if ( !$first ) {
2225                         $retVal .= ' ';
2226                 } else {
2227                         $first = false;
2228                 }
2229
2230                 if ( wfIsWindows() ) {
2231                         // Escaping for an MSVC-style command line parser and CMD.EXE
2232                         // @codingStandardsIgnoreStart For long URLs
2233                         // Refs:
2234                         //  * https://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2235                         //  * https://technet.microsoft.com/en-us/library/cc723564.aspx
2236                         //  * T15518
2237                         //  * CR r63214
2238                         // Double the backslashes before any double quotes. Escape the double quotes.
2239                         // @codingStandardsIgnoreEnd
2240                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2241                         $arg = '';
2242                         $iteration = 0;
2243                         foreach ( $tokens as $token ) {
2244                                 if ( $iteration % 2 == 1 ) {
2245                                         // Delimiter, a double quote preceded by zero or more slashes
2246                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2247                                 } elseif ( $iteration % 4 == 2 ) {
2248                                         // ^ in $token will be outside quotes, need to be escaped
2249                                         $arg .= str_replace( '^', '^^', $token );
2250                                 } else { // $iteration % 4 == 0
2251                                         // ^ in $token will appear inside double quotes, so leave as is
2252                                         $arg .= $token;
2253                                 }
2254                                 $iteration++;
2255                         }
2256                         // Double the backslashes before the end of the string, because
2257                         // we will soon add a quote
2258                         $m = [];
2259                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2260                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2261                         }
2262
2263                         // Add surrounding quotes
2264                         $retVal .= '"' . $arg . '"';
2265                 } else {
2266                         $retVal .= escapeshellarg( $arg );
2267                 }
2268         }
2269         return $retVal;
2270 }
2271
2272 /**
2273  * Check if wfShellExec() is effectively disabled via php.ini config
2274  *
2275  * @return bool|string False or 'disabled'
2276  * @since 1.22
2277  */
2278 function wfShellExecDisabled() {
2279         static $disabled = null;
2280         if ( is_null( $disabled ) ) {
2281                 if ( !function_exists( 'proc_open' ) ) {
2282                         wfDebug( "proc_open() is disabled\n" );
2283                         $disabled = 'disabled';
2284                 } else {
2285                         $disabled = false;
2286                 }
2287         }
2288         return $disabled;
2289 }
2290
2291 /**
2292  * Execute a shell command, with time and memory limits mirrored from the PHP
2293  * configuration if supported.
2294  *
2295  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2296  *   or an array of unescaped arguments, in which case each value will be escaped
2297  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2298  * @param null|mixed &$retval Optional, will receive the program's exit code.
2299  *   (non-zero is usually failure). If there is an error from
2300  *   read, select, or proc_open(), this will be set to -1.
2301  * @param array $environ Optional environment variables which should be
2302  *   added to the executed command environment.
2303  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2304  *   this overwrites the global wgMaxShell* limits.
2305  * @param array $options Array of options:
2306  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2307  *     including errors from limit.sh
2308  *   - profileMethod: By default this function will profile based on the calling
2309  *     method. Set this to a string for an alternative method to profile from
2310  *
2311  * @return string Collected stdout as a string
2312  */
2313 function wfShellExec( $cmd, &$retval = null, $environ = [],
2314         $limits = [], $options = []
2315 ) {
2316         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2317                 $wgMaxShellWallClockTime, $wgShellCgroup;
2318
2319         $disabled = wfShellExecDisabled();
2320         if ( $disabled ) {
2321                 $retval = 1;
2322                 return 'Unable to run external programs, proc_open() is disabled.';
2323         }
2324
2325         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2326         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2327
2328         wfInitShellLocale();
2329
2330         $envcmd = '';
2331         foreach ( $environ as $k => $v ) {
2332                 if ( wfIsWindows() ) {
2333                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2334                          * appear in the environment variable, so we must use carat escaping as documented in
2335                          * https://technet.microsoft.com/en-us/library/cc723564.aspx
2336                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2337                          * are listed there but doesn't appear to need it.
2338                          */
2339                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2340                 } else {
2341                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2342                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2343                          */
2344                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2345                 }
2346         }
2347         if ( is_array( $cmd ) ) {
2348                 $cmd = wfEscapeShellArg( $cmd );
2349         }
2350
2351         $cmd = $envcmd . $cmd;
2352
2353         $useLogPipe = false;
2354         if ( is_executable( '/bin/bash' ) ) {
2355                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2356                 if ( isset( $limits['walltime'] ) ) {
2357                         $wallTime = intval( $limits['walltime'] );
2358                 } elseif ( isset( $limits['time'] ) ) {
2359                         $wallTime = $time;
2360                 } else {
2361                         $wallTime = intval( $wgMaxShellWallClockTime );
2362                 }
2363                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2364                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2365
2366                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2367                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2368                                 escapeshellarg( $cmd ) . ' ' .
2369                                 escapeshellarg(
2370                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2371                                         "MW_CPU_LIMIT=$time; " .
2372                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2373                                         "MW_MEM_LIMIT=$mem; " .
2374                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2375                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2376                                         "MW_USE_LOG_PIPE=yes"
2377                                 );
2378                         $useLogPipe = true;
2379                 } elseif ( $includeStderr ) {
2380                         $cmd .= ' 2>&1';
2381                 }
2382         } elseif ( $includeStderr ) {
2383                 $cmd .= ' 2>&1';
2384         }
2385         wfDebug( "wfShellExec: $cmd\n" );
2386
2387         // Don't try to execute commands that exceed Linux's MAX_ARG_STRLEN.
2388         // Other platforms may be more accomodating, but we don't want to be
2389         // accomodating, because very long commands probably include user
2390         // input. See T129506.
2391         if ( strlen( $cmd ) > SHELL_MAX_ARG_STRLEN ) {
2392                 throw new Exception( __METHOD__ .
2393                         '(): total length of $cmd must not exceed SHELL_MAX_ARG_STRLEN' );
2394         }
2395
2396         $desc = [
2397                 0 => [ 'file', 'php://stdin', 'r' ],
2398                 1 => [ 'pipe', 'w' ],
2399                 2 => [ 'file', 'php://stderr', 'w' ] ];
2400         if ( $useLogPipe ) {
2401                 $desc[3] = [ 'pipe', 'w' ];
2402         }
2403         $pipes = null;
2404         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2405         $proc = proc_open( $cmd, $desc, $pipes );
2406         if ( !$proc ) {
2407                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2408                 $retval = -1;
2409                 return '';
2410         }
2411         $outBuffer = $logBuffer = '';
2412         $emptyArray = [];
2413         $status = false;
2414         $logMsg = false;
2415
2416         /* According to the documentation, it is possible for stream_select()
2417          * to fail due to EINTR. I haven't managed to induce this in testing
2418          * despite sending various signals. If it did happen, the error
2419          * message would take the form:
2420          *
2421          * stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2422          *
2423          * where [4] is the value of the macro EINTR and "Interrupted system
2424          * call" is string which according to the Linux manual is "possibly"
2425          * localised according to LC_MESSAGES.
2426          */
2427         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2428         $eintrMessage = "stream_select(): unable to select [$eintr]";
2429
2430         $running = true;
2431         $timeout = null;
2432         $numReadyPipes = 0;
2433
2434         while ( $running === true || $numReadyPipes !== 0 ) {
2435                 if ( $running ) {
2436                         $status = proc_get_status( $proc );
2437                         // If the process has terminated, switch to nonblocking selects
2438                         // for getting any data still waiting to be read.
2439                         if ( !$status['running'] ) {
2440                                 $running = false;
2441                                 $timeout = 0;
2442                         }
2443                 }
2444
2445                 $readyPipes = $pipes;
2446
2447                 // Clear last error
2448                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2449                 @trigger_error( '' );
2450                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2451                 if ( $numReadyPipes === false ) {
2452                         // @codingStandardsIgnoreEnd
2453                         $error = error_get_last();
2454                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2455                                 continue;
2456                         } else {
2457                                 trigger_error( $error['message'], E_USER_WARNING );
2458                                 $logMsg = $error['message'];
2459                                 break;
2460                         }
2461                 }
2462                 foreach ( $readyPipes as $fd => $pipe ) {
2463                         $block = fread( $pipe, 65536 );
2464                         if ( $block === '' ) {
2465                                 // End of file
2466                                 fclose( $pipes[$fd] );
2467                                 unset( $pipes[$fd] );
2468                                 if ( !$pipes ) {
2469                                         break 2;
2470                                 }
2471                         } elseif ( $block === false ) {
2472                                 // Read error
2473                                 $logMsg = "Error reading from pipe";
2474                                 break 2;
2475                         } elseif ( $fd == 1 ) {
2476                                 // From stdout
2477                                 $outBuffer .= $block;
2478                         } elseif ( $fd == 3 ) {
2479                                 // From log FD
2480                                 $logBuffer .= $block;
2481                                 if ( strpos( $block, "\n" ) !== false ) {
2482                                         $lines = explode( "\n", $logBuffer );
2483                                         $logBuffer = array_pop( $lines );
2484                                         foreach ( $lines as $line ) {
2485                                                 wfDebugLog( 'exec', $line );
2486                                         }
2487                                 }
2488                         }
2489                 }
2490         }
2491
2492         foreach ( $pipes as $pipe ) {
2493                 fclose( $pipe );
2494         }
2495
2496         // Use the status previously collected if possible, since proc_get_status()
2497         // just calls waitpid() which will not return anything useful the second time.
2498         if ( $running ) {
2499                 $status = proc_get_status( $proc );
2500         }
2501
2502         if ( $logMsg !== false ) {
2503                 // Read/select error
2504                 $retval = -1;
2505                 proc_close( $proc );
2506         } elseif ( $status['signaled'] ) {
2507                 $logMsg = "Exited with signal {$status['termsig']}";
2508                 $retval = 128 + $status['termsig'];
2509                 proc_close( $proc );
2510         } else {
2511                 if ( $status['running'] ) {
2512                         $retval = proc_close( $proc );
2513                 } else {
2514                         $retval = $status['exitcode'];
2515                         proc_close( $proc );
2516                 }
2517                 if ( $retval == 127 ) {
2518                         $logMsg = "Possibly missing executable file";
2519                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2520                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2521                 }
2522         }
2523
2524         if ( $logMsg !== false ) {
2525                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2526         }
2527
2528         return $outBuffer;
2529 }
2530
2531 /**
2532  * Execute a shell command, returning both stdout and stderr. Convenience
2533  * function, as all the arguments to wfShellExec can become unwieldy.
2534  *
2535  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2536  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2537  *   or an array of unescaped arguments, in which case each value will be escaped
2538  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2539  * @param null|mixed &$retval Optional, will receive the program's exit code.
2540  *   (non-zero is usually failure)
2541  * @param array $environ Optional environment variables which should be
2542  *   added to the executed command environment.
2543  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2544  *   this overwrites the global wgMaxShell* limits.
2545  * @return string Collected stdout and stderr as a string
2546  */
2547 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2548         return wfShellExec( $cmd, $retval, $environ, $limits,
2549                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2550 }
2551
2552 /**
2553  * Workaround for https://bugs.php.net/bug.php?id=45132
2554  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2555  */
2556 function wfInitShellLocale() {
2557         static $done = false;
2558         if ( $done ) {
2559                 return;
2560         }
2561         $done = true;
2562         global $wgShellLocale;
2563         putenv( "LC_CTYPE=$wgShellLocale" );
2564         setlocale( LC_CTYPE, $wgShellLocale );
2565 }
2566
2567 /**
2568  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2569  * Note that $parameters should be a flat array and an option with an argument
2570  * should consist of two consecutive items in the array (do not use "--option value").
2571  *
2572  * @param string $script MediaWiki cli script path
2573  * @param array $parameters Arguments and options to the script
2574  * @param array $options Associative array of options:
2575  *              'php': The path to the php executable
2576  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2577  * @return string
2578  */
2579 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2580         global $wgPhpCli;
2581         // Give site config file a chance to run the script in a wrapper.
2582         // The caller may likely want to call wfBasename() on $script.
2583         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2584         $cmd = isset( $options['php'] ) ? [ $options['php'] ] : [ $wgPhpCli ];
2585         if ( isset( $options['wrapper'] ) ) {
2586                 $cmd[] = $options['wrapper'];
2587         }
2588         $cmd[] = $script;
2589         // Escape each parameter for shell
2590         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
2591 }
2592
2593 /**
2594  * wfMerge attempts to merge differences between three texts.
2595  * Returns true for a clean merge and false for failure or a conflict.
2596  *
2597  * @param string $old
2598  * @param string $mine
2599  * @param string $yours
2600  * @param string $result
2601  * @return bool
2602  */
2603 function wfMerge( $old, $mine, $yours, &$result ) {
2604         global $wgDiff3;
2605
2606         # This check may also protect against code injection in
2607         # case of broken installations.
2608         MediaWiki\suppressWarnings();
2609         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2610         MediaWiki\restoreWarnings();
2611
2612         if ( !$haveDiff3 ) {
2613                 wfDebug( "diff3 not found\n" );
2614                 return false;
2615         }
2616
2617         # Make temporary files
2618         $td = wfTempDir();
2619         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2620         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2621         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2622
2623         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2624         #       a newline character. To avoid this, we normalize the trailing whitespace before
2625         #       creating the diff.
2626
2627         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2628         fclose( $oldtextFile );
2629         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2630         fclose( $mytextFile );
2631         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2632         fclose( $yourtextFile );
2633
2634         # Check for a conflict
2635         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
2636                 $oldtextName, $yourtextName );
2637         $handle = popen( $cmd, 'r' );
2638
2639         if ( fgets( $handle, 1024 ) ) {
2640                 $conflict = true;
2641         } else {
2642                 $conflict = false;
2643         }
2644         pclose( $handle );
2645
2646         # Merge differences
2647         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2648                 $oldtextName, $yourtextName );
2649         $handle = popen( $cmd, 'r' );
2650         $result = '';
2651         do {
2652                 $data = fread( $handle, 8192 );
2653                 if ( strlen( $data ) == 0 ) {
2654                         break;
2655                 }
2656                 $result .= $data;
2657         } while ( true );
2658         pclose( $handle );
2659         unlink( $mytextName );
2660         unlink( $oldtextName );
2661         unlink( $yourtextName );
2662
2663         if ( $result === '' && $old !== '' && !$conflict ) {
2664                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2665                 $conflict = true;
2666         }
2667         return !$conflict;
2668 }
2669
2670 /**
2671  * Returns unified plain-text diff of two texts.
2672  * "Useful" for machine processing of diffs.
2673  *
2674  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2675  *
2676  * @param string $before The text before the changes.
2677  * @param string $after The text after the changes.
2678  * @param string $params Command-line options for the diff command.
2679  * @return string Unified diff of $before and $after
2680  */
2681 function wfDiff( $before, $after, $params = '-u' ) {
2682         if ( $before == $after ) {
2683                 return '';
2684         }
2685
2686         global $wgDiff;
2687         MediaWiki\suppressWarnings();
2688         $haveDiff = $wgDiff && file_exists( $wgDiff );
2689         MediaWiki\restoreWarnings();
2690
2691         # This check may also protect against code injection in
2692         # case of broken installations.
2693         if ( !$haveDiff ) {
2694                 wfDebug( "diff executable not found\n" );
2695                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2696                 $format = new UnifiedDiffFormatter();
2697                 return $format->format( $diffs );
2698         }
2699
2700         # Make temporary files
2701         $td = wfTempDir();
2702         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2703         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2704
2705         fwrite( $oldtextFile, $before );
2706         fclose( $oldtextFile );
2707         fwrite( $newtextFile, $after );
2708         fclose( $newtextFile );
2709
2710         // Get the diff of the two files
2711         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2712
2713         $h = popen( $cmd, 'r' );
2714         if ( !$h ) {
2715                 unlink( $oldtextName );
2716                 unlink( $newtextName );
2717                 throw new Exception( __METHOD__ . '(): popen() failed' );
2718         }
2719
2720         $diff = '';
2721
2722         do {
2723                 $data = fread( $h, 8192 );
2724                 if ( strlen( $data ) == 0 ) {
2725                         break;
2726                 }
2727                 $diff .= $data;
2728         } while ( true );
2729
2730         // Clean up
2731         pclose( $h );
2732         unlink( $oldtextName );
2733         unlink( $newtextName );
2734
2735         // Kill the --- and +++ lines. They're not useful.
2736         $diff_lines = explode( "\n", $diff );
2737         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2738                 unset( $diff_lines[0] );
2739         }
2740         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2741                 unset( $diff_lines[1] );
2742         }
2743
2744         $diff = implode( "\n", $diff_lines );
2745
2746         return $diff;
2747 }
2748
2749 /**
2750  * This function works like "use VERSION" in Perl, the program will die with a
2751  * backtrace if the current version of PHP is less than the version provided
2752  *
2753  * This is useful for extensions which due to their nature are not kept in sync
2754  * with releases, and might depend on other versions of PHP than the main code
2755  *
2756  * Note: PHP might die due to parsing errors in some cases before it ever
2757  *       manages to call this function, such is life
2758  *
2759  * @see perldoc -f use
2760  *
2761  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2762  * @throws MWException
2763  */
2764 function wfUsePHP( $req_ver ) {
2765         $php_ver = PHP_VERSION;
2766
2767         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2768                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2769         }
2770 }
2771
2772 /**
2773  * This function works like "use VERSION" in Perl except it checks the version
2774  * of MediaWiki, the program will die with a backtrace if the current version
2775  * of MediaWiki is less than the version provided.
2776  *
2777  * This is useful for extensions which due to their nature are not kept in sync
2778  * with releases
2779  *
2780  * Note: Due to the behavior of PHP's version_compare() which is used in this
2781  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2782  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2783  * targeted version number. For example if you wanted to allow any variation
2784  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2785  * not result in the same comparison due to the internal logic of
2786  * version_compare().
2787  *
2788  * @see perldoc -f use
2789  *
2790  * @deprecated since 1.26, use the "requires' property of extension.json
2791  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2792  * @throws MWException
2793  */
2794 function wfUseMW( $req_ver ) {
2795         global $wgVersion;
2796
2797         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2798                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2799         }
2800 }
2801
2802 /**
2803  * Return the final portion of a pathname.
2804  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2805  * https://bugs.php.net/bug.php?id=33898
2806  *
2807  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2808  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2809  *
2810  * @param string $path
2811  * @param string $suffix String to remove if present
2812  * @return string
2813  */
2814 function wfBaseName( $path, $suffix = '' ) {
2815         if ( $suffix == '' ) {
2816                 $encSuffix = '';
2817         } else {
2818                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2819         }
2820
2821         $matches = [];
2822         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2823                 return $matches[1];
2824         } else {
2825                 return '';
2826         }
2827 }
2828
2829 /**
2830  * Generate a relative path name to the given file.
2831  * May explode on non-matching case-insensitive paths,
2832  * funky symlinks, etc.
2833  *
2834  * @param string $path Absolute destination path including target filename
2835  * @param string $from Absolute source path, directory only
2836  * @return string
2837  */
2838 function wfRelativePath( $path, $from ) {
2839         // Normalize mixed input on Windows...
2840         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2841         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2842
2843         // Trim trailing slashes -- fix for drive root
2844         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2845         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2846
2847         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2848         $against = explode( DIRECTORY_SEPARATOR, $from );
2849
2850         if ( $pieces[0] !== $against[0] ) {
2851                 // Non-matching Windows drive letters?
2852                 // Return a full path.
2853                 return $path;
2854         }
2855
2856         // Trim off common prefix
2857         while ( count( $pieces ) && count( $against )
2858                 && $pieces[0] == $against[0] ) {
2859                 array_shift( $pieces );
2860                 array_shift( $against );
2861         }
2862
2863         // relative dots to bump us to the parent
2864         while ( count( $against ) ) {
2865                 array_unshift( $pieces, '..' );
2866                 array_shift( $against );
2867         }
2868
2869         array_push( $pieces, wfBaseName( $path ) );
2870
2871         return implode( DIRECTORY_SEPARATOR, $pieces );
2872 }
2873
2874 /**
2875  * Convert an arbitrarily-long digit string from one numeric base
2876  * to another, optionally zero-padding to a minimum column width.
2877  *
2878  * Supports base 2 through 36; digit values 10-36 are represented
2879  * as lowercase letters a-z. Input is case-insensitive.
2880  *
2881  * @deprecated since 1.27 Use Wikimedia\base_convert() directly
2882  *
2883  * @param string $input Input number
2884  * @param int $sourceBase Base of the input number
2885  * @param int $destBase Desired base of the output
2886  * @param int $pad Minimum number of digits in the output (pad with zeroes)
2887  * @param bool $lowercase Whether to output in lowercase or uppercase
2888  * @param string $engine Either "gmp", "bcmath", or "php"
2889  * @return string|bool The output number as a string, or false on error
2890  */
2891 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
2892         $lowercase = true, $engine = 'auto'
2893 ) {
2894         return Wikimedia\base_convert( $input, $sourceBase, $destBase, $pad, $lowercase, $engine );
2895 }
2896
2897 /**
2898  * @deprecated since 1.27, PHP's session generation isn't used with
2899  *  MediaWiki\Session\SessionManager
2900  */
2901 function wfFixSessionID() {
2902         wfDeprecated( __FUNCTION__, '1.27' );
2903 }
2904
2905 /**
2906  * Reset the session id
2907  *
2908  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2909  * @since 1.22
2910  */
2911 function wfResetSessionID() {
2912         wfDeprecated( __FUNCTION__, '1.27' );
2913         $session = SessionManager::getGlobalSession();
2914         $delay = $session->delaySave();
2915
2916         $session->resetId();
2917
2918         // Make sure a session is started, since that's what the old
2919         // wfResetSessionID() did.
2920         if ( session_id() !== $session->getId() ) {
2921                 wfSetupSession( $session->getId() );
2922         }
2923
2924         ScopedCallback::consume( $delay );
2925 }
2926
2927 /**
2928  * Initialise php session
2929  *
2930  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2931  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2932  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2933  *  here), then calling $session->persist().
2934  * @param bool|string $sessionId
2935  */
2936 function wfSetupSession( $sessionId = false ) {
2937         wfDeprecated( __FUNCTION__, '1.27' );
2938
2939         if ( $sessionId ) {
2940                 session_id( $sessionId );
2941         }
2942
2943         $session = SessionManager::getGlobalSession();
2944         $session->persist();
2945
2946         if ( session_id() !== $session->getId() ) {
2947                 session_id( $session->getId() );
2948         }
2949         MediaWiki\quietCall( 'session_start' );
2950 }
2951
2952 /**
2953  * Get an object from the precompiled serialized directory
2954  *
2955  * @param string $name
2956  * @return mixed The variable on success, false on failure
2957  */
2958 function wfGetPrecompiledData( $name ) {
2959         global $IP;
2960
2961         $file = "$IP/serialized/$name";
2962         if ( file_exists( $file ) ) {
2963                 $blob = file_get_contents( $file );
2964                 if ( $blob ) {
2965                         return unserialize( $blob );
2966                 }
2967         }
2968         return false;
2969 }
2970
2971 /**
2972  * Make a cache key for the local wiki.
2973  *
2974  * @param string $args,...
2975  * @return string
2976  */
2977 function wfMemcKey( /*...*/ ) {
2978         return call_user_func_array(
2979                 [ ObjectCache::getLocalClusterInstance(), 'makeKey' ],
2980                 func_get_args()
2981         );
2982 }
2983
2984 /**
2985  * Make a cache key for a foreign DB.
2986  *
2987  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2988  *
2989  * @param string $db
2990  * @param string $prefix
2991  * @param string $args,...
2992  * @return string
2993  */
2994 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
2995         $args = array_slice( func_get_args(), 2 );
2996         $keyspace = $prefix ? "$db-$prefix" : $db;
2997         return call_user_func_array(
2998                 [ ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ],
2999                 [ $keyspace, $args ]
3000         );
3001 }
3002
3003 /**
3004  * Make a cache key with database-agnostic prefix.
3005  *
3006  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3007  * instead. Must have a prefix as otherwise keys that use a database name
3008  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3009  *
3010  * @since 1.26
3011  * @param string $args,...
3012  * @return string
3013  */
3014 function wfGlobalCacheKey( /*...*/ ) {
3015         return call_user_func_array(
3016                 [ ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ],
3017                 func_get_args()
3018         );
3019 }
3020
3021 /**
3022  * Get an ASCII string identifying this wiki
3023  * This is used as a prefix in memcached keys
3024  *
3025  * @return string
3026  */
3027 function wfWikiID() {
3028         global $wgDBprefix, $wgDBname;
3029         if ( $wgDBprefix ) {
3030                 return "$wgDBname-$wgDBprefix";
3031         } else {
3032                 return $wgDBname;
3033         }
3034 }
3035
3036 /**
3037  * Split a wiki ID into DB name and table prefix
3038  *
3039  * @param string $wiki
3040  *
3041  * @return array
3042  */
3043 function wfSplitWikiID( $wiki ) {
3044         $bits = explode( '-', $wiki, 2 );
3045         if ( count( $bits ) < 2 ) {
3046                 $bits[] = '';
3047         }
3048         return $bits;
3049 }
3050
3051 /**
3052  * Get a Database object.
3053  *
3054  * @param int $db Index of the connection to get. May be DB_MASTER for the
3055  *            master (for write queries), DB_REPLICA for potentially lagged read
3056  *            queries, or an integer >= 0 for a particular server.
3057  *
3058  * @param string|string[] $groups Query groups. An array of group names that this query
3059  *                belongs to. May contain a single string if the query is only
3060  *                in one group.
3061  *
3062  * @param string|bool $wiki The wiki ID, or false for the current wiki
3063  *
3064  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
3065  * will always return the same object, unless the underlying connection or load
3066  * balancer is manually destroyed.
3067  *
3068  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3069  * updater to ensure that a proper database is being updated.
3070  *
3071  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
3072  *       on an injected instance of LoadBalancer.
3073  *
3074  * @return Database
3075  */
3076 function wfGetDB( $db, $groups = [], $wiki = false ) {
3077         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3078 }
3079
3080 /**
3081  * Get a load balancer object.
3082  *
3083  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancer()
3084  *              or MediaWikiServices::getDBLoadBalancerFactory() instead.
3085  *
3086  * @param string|bool $wiki Wiki ID, or false for the current wiki
3087  * @return LoadBalancer
3088  */
3089 function wfGetLB( $wiki = false ) {
3090         if ( $wiki === false ) {
3091                 return \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancer();
3092         } else {
3093                 $factory = \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
3094                 return $factory->getMainLB( $wiki );
3095         }
3096 }
3097
3098 /**
3099  * Get the load balancer factory object
3100  *
3101  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancerFactory() instead.
3102  *
3103  * @return LBFactory
3104  */
3105 function wfGetLBFactory() {
3106         return \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
3107 }
3108
3109 /**
3110  * Find a file.
3111  * Shortcut for RepoGroup::singleton()->findFile()
3112  *
3113  * @param string $title String or Title object
3114  * @param array $options Associative array of options (see RepoGroup::findFile)
3115  * @return File|bool File, or false if the file does not exist
3116  */
3117 function wfFindFile( $title, $options = [] ) {
3118         return RepoGroup::singleton()->findFile( $title, $options );
3119 }
3120
3121 /**
3122  * Get an object referring to a locally registered file.
3123  * Returns a valid placeholder object if the file does not exist.
3124  *
3125  * @param Title|string $title
3126  * @return LocalFile|null A File, or null if passed an invalid Title
3127  */
3128 function wfLocalFile( $title ) {
3129         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3130 }
3131
3132 /**
3133  * Should low-performance queries be disabled?
3134  *
3135  * @return bool
3136  * @codeCoverageIgnore
3137  */
3138 function wfQueriesMustScale() {
3139         global $wgMiserMode;
3140         return $wgMiserMode
3141                 || ( SiteStats::pages() > 100000
3142                 && SiteStats::edits() > 1000000
3143                 && SiteStats::users() > 10000 );
3144 }
3145
3146 /**
3147  * Get the path to a specified script file, respecting file
3148  * extensions; this is a wrapper around $wgScriptPath etc.
3149  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3150  *
3151  * @param string $script Script filename, sans extension
3152  * @return string
3153  */
3154 function wfScript( $script = 'index' ) {
3155         global $wgScriptPath, $wgScript, $wgLoadScript;
3156         if ( $script === 'index' ) {
3157                 return $wgScript;
3158         } elseif ( $script === 'load' ) {
3159                 return $wgLoadScript;
3160         } else {
3161                 return "{$wgScriptPath}/{$script}.php";
3162         }
3163 }
3164
3165 /**
3166  * Get the script URL.
3167  *
3168  * @return string Script URL
3169  */
3170 function wfGetScriptUrl() {
3171         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3172                 /* as it was called, minus the query string.
3173                  *
3174                  * Some sites use Apache rewrite rules to handle subdomains,
3175                  * and have PHP set up in a weird way that causes PHP_SELF
3176                  * to contain the rewritten URL instead of the one that the
3177                  * outside world sees.
3178                  *
3179                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
3180                  * provides containing the "before" URL.
3181                  */
3182                 return $_SERVER['SCRIPT_NAME'];
3183         } else {
3184                 return $_SERVER['URL'];
3185         }
3186 }
3187
3188 /**
3189  * Convenience function converts boolean values into "true"
3190  * or "false" (string) values
3191  *
3192  * @param bool $value
3193  * @return string
3194  */
3195 function wfBoolToStr( $value ) {
3196         return $value ? 'true' : 'false';
3197 }
3198
3199 /**
3200  * Get a platform-independent path to the null file, e.g. /dev/null
3201  *
3202  * @return string
3203  */
3204 function wfGetNull() {
3205         return wfIsWindows() ? 'NUL' : '/dev/null';
3206 }
3207
3208 /**
3209  * Waits for the replica DBs to catch up to the master position
3210  *
3211  * Use this when updating very large numbers of rows, as in maintenance scripts,
3212  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
3213  *
3214  * By default this waits on the main DB cluster of the current wiki.
3215  * If $cluster is set to "*" it will wait on all DB clusters, including
3216  * external ones. If the lag being waiting on is caused by the code that
3217  * does this check, it makes since to use $ifWritesSince, particularly if
3218  * cluster is "*", to avoid excess overhead.
3219  *
3220  * Never call this function after a big DB write that is still in a transaction.
3221  * This only makes sense after the possible lag inducing changes were committed.
3222  *
3223  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3224  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3225  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3226  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3227  * @return bool Success (able to connect and no timeouts reached)
3228  * @deprecated since 1.27 Use LBFactory::waitForReplication
3229  */
3230 function wfWaitForSlaves(
3231         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3232 ) {
3233         if ( $timeout === null ) {
3234                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3235         }
3236
3237         if ( $cluster === '*' ) {
3238                 $cluster = false;
3239                 $wiki = false;
3240         } elseif ( $wiki === false ) {
3241                 $wiki = wfWikiID();
3242         }
3243
3244         try {
3245                 wfGetLBFactory()->waitForReplication( [
3246                         'wiki' => $wiki,
3247                         'cluster' => $cluster,
3248                         'timeout' => $timeout,
3249                         // B/C: first argument used to be "max seconds of lag"; ignore such values
3250                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
3251                 ] );
3252         } catch ( DBReplicationWaitError $e ) {
3253                 return false;
3254         }
3255
3256         return true;
3257 }
3258
3259 /**
3260  * Count down from $seconds to zero on the terminal, with a one-second pause
3261  * between showing each number. For use in command-line scripts.
3262  *
3263  * @codeCoverageIgnore
3264  * @param int $seconds
3265  */
3266 function wfCountDown( $seconds ) {
3267         for ( $i = $seconds; $i >= 0; $i-- ) {
3268                 if ( $i != $seconds ) {
3269                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3270                 }
3271                 echo $i;
3272                 flush();
3273                 if ( $i ) {
3274                         sleep( 1 );
3275                 }
3276         }
3277         echo "\n";
3278 }
3279
3280 /**
3281  * Replace all invalid characters with '-'.
3282  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
3283  * By default, $wgIllegalFileChars includes ':', '/', '\'.
3284  *
3285  * @param string $name Filename to process
3286  * @return string
3287  */
3288 function wfStripIllegalFilenameChars( $name ) {
3289         global $wgIllegalFileChars;
3290         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3291         $name = preg_replace(
3292                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3293                 '-',
3294                 $name
3295         );
3296         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
3297         $name = wfBaseName( $name );
3298         return $name;
3299 }
3300
3301 /**
3302  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3303  *
3304  * @return int Resulting value of the memory limit.
3305  */
3306 function wfMemoryLimit() {
3307         global $wgMemoryLimit;
3308         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3309         if ( $memlimit != -1 ) {
3310                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3311                 if ( $conflimit == -1 ) {
3312                         wfDebug( "Removing PHP's memory limit\n" );
3313                         MediaWiki\suppressWarnings();
3314                         ini_set( 'memory_limit', $conflimit );
3315                         MediaWiki\restoreWarnings();
3316                         return $conflimit;
3317                 } elseif ( $conflimit > $memlimit ) {
3318                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3319                         MediaWiki\suppressWarnings();
3320                         ini_set( 'memory_limit', $conflimit );
3321                         MediaWiki\restoreWarnings();
3322                         return $conflimit;
3323                 }
3324         }
3325         return $memlimit;
3326 }
3327
3328 /**
3329  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3330  *
3331  * @return int Prior time limit
3332  * @since 1.26
3333  */
3334 function wfTransactionalTimeLimit() {
3335         global $wgTransactionalTimeLimit;
3336
3337         $timeLimit = ini_get( 'max_execution_time' );
3338         // Note that CLI scripts use 0
3339         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3340                 set_time_limit( $wgTransactionalTimeLimit );
3341         }
3342
3343         ignore_user_abort( true ); // ignore client disconnects
3344
3345         return $timeLimit;
3346 }
3347
3348 /**
3349  * Converts shorthand byte notation to integer form
3350  *
3351  * @param string $string
3352  * @param int $default Returned if $string is empty
3353  * @return int
3354  */
3355 function wfShorthandToInteger( $string = '', $default = -1 ) {
3356         $string = trim( $string );
3357         if ( $string === '' ) {
3358                 return $default;
3359         }
3360         $last = $string[strlen( $string ) - 1];
3361         $val = intval( $string );
3362         switch ( $last ) {
3363                 case 'g':
3364                 case 'G':
3365                         $val *= 1024;
3366                         // break intentionally missing
3367                 case 'm':
3368                 case 'M':
3369                         $val *= 1024;
3370                         // break intentionally missing
3371                 case 'k':
3372                 case 'K':
3373                         $val *= 1024;
3374         }
3375
3376         return $val;
3377 }
3378
3379 /**
3380  * Get the normalised IETF language tag
3381  * See unit test for examples.
3382  *
3383  * @param string $code The language code.
3384  * @return string The language code which complying with BCP 47 standards.
3385  */
3386 function wfBCP47( $code ) {
3387         $codeSegment = explode( '-', $code );
3388         $codeBCP = [];
3389         foreach ( $codeSegment as $segNo => $seg ) {
3390                 // when previous segment is x, it is a private segment and should be lc
3391                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3392                         $codeBCP[$segNo] = strtolower( $seg );
3393                 // ISO 3166 country code
3394                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3395                         $codeBCP[$segNo] = strtoupper( $seg );
3396                 // ISO 15924 script code
3397                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3398                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3399                 // Use lowercase for other cases
3400                 } else {
3401                         $codeBCP[$segNo] = strtolower( $seg );
3402                 }
3403         }
3404         $langCode = implode( '-', $codeBCP );
3405         return $langCode;
3406 }
3407
3408 /**
3409  * Get a specific cache object.
3410  *
3411  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3412  * @return BagOStuff
3413  */
3414 function wfGetCache( $cacheType ) {
3415         return ObjectCache::getInstance( $cacheType );
3416 }
3417
3418 /**
3419  * Get the main cache object
3420  *
3421  * @return BagOStuff
3422  */
3423 function wfGetMainCache() {
3424         global $wgMainCacheType;
3425         return ObjectCache::getInstance( $wgMainCacheType );
3426 }
3427
3428 /**
3429  * Get the cache object used by the message cache
3430  *
3431  * @return BagOStuff
3432  */
3433 function wfGetMessageCacheStorage() {
3434         global $wgMessageCacheType;
3435         return ObjectCache::getInstance( $wgMessageCacheType );
3436 }
3437
3438 /**
3439  * Get the cache object used by the parser cache
3440  *
3441  * @return BagOStuff
3442  */
3443 function wfGetParserCacheStorage() {
3444         global $wgParserCacheType;
3445         return ObjectCache::getInstance( $wgParserCacheType );
3446 }
3447
3448 /**
3449  * Call hook functions defined in $wgHooks
3450  *
3451  * @param string $event Event name
3452  * @param array $args Parameters passed to hook functions
3453  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3454  *
3455  * @return bool True if no handler aborted the hook
3456  * @deprecated since 1.25 - use Hooks::run
3457  */
3458 function wfRunHooks( $event, array $args = [], $deprecatedVersion = null ) {
3459         return Hooks::run( $event, $args, $deprecatedVersion );
3460 }
3461
3462 /**
3463  * Wrapper around php's unpack.
3464  *
3465  * @param string $format The format string (See php's docs)
3466  * @param string $data A binary string of binary data
3467  * @param int|bool $length The minimum length of $data or false. This is to
3468  *      prevent reading beyond the end of $data. false to disable the check.
3469  *
3470  * Also be careful when using this function to read unsigned 32 bit integer
3471  * because php might make it negative.
3472  *
3473  * @throws MWException If $data not long enough, or if unpack fails
3474  * @return array Associative array of the extracted data
3475  */
3476 function wfUnpack( $format, $data, $length = false ) {
3477         if ( $length !== false ) {
3478                 $realLen = strlen( $data );
3479                 if ( $realLen < $length ) {
3480                         throw new MWException( "Tried to use wfUnpack on a "
3481                                 . "string of length $realLen, but needed one "
3482                                 . "of at least length $length."
3483                         );
3484                 }
3485         }
3486
3487         MediaWiki\suppressWarnings();
3488         $result = unpack( $format, $data );
3489         MediaWiki\restoreWarnings();
3490
3491         if ( $result === false ) {
3492                 // If it cannot extract the packed data.
3493                 throw new MWException( "unpack could not unpack binary data" );
3494         }
3495         return $result;
3496 }
3497
3498 /**
3499  * Determine if an image exists on the 'bad image list'.
3500  *
3501  * The format of MediaWiki:Bad_image_list is as follows:
3502  *    * Only list items (lines starting with "*") are considered
3503  *    * The first link on a line must be a link to a bad image
3504  *    * Any subsequent links on the same line are considered to be exceptions,
3505  *      i.e. articles where the image may occur inline.
3506  *
3507  * @param string $name The image name to check
3508  * @param Title|bool $contextTitle The page on which the image occurs, if known
3509  * @param string $blacklist Wikitext of a file blacklist
3510  * @return bool
3511  */
3512 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3513         # Handle redirects; callers almost always hit wfFindFile() anyway,
3514         # so just use that method because it has a fast process cache.
3515         $file = wfFindFile( $name ); // get the final name
3516         $name = $file ? $file->getTitle()->getDBkey() : $name;
3517
3518         # Run the extension hook
3519         $bad = false;
3520         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3521                 return $bad;
3522         }
3523
3524         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3525         $key = wfMemcKey( 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist ) );
3526         $badImages = $cache->get( $key );
3527
3528         if ( $badImages === false ) { // cache miss
3529                 if ( $blacklist === null ) {
3530                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3531                 }
3532                 # Build the list now
3533                 $badImages = [];
3534                 $lines = explode( "\n", $blacklist );
3535                 foreach ( $lines as $line ) {
3536                         # List items only
3537                         if ( substr( $line, 0, 1 ) !== '*' ) {
3538                                 continue;
3539                         }
3540
3541                         # Find all links
3542                         $m = [];
3543                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3544                                 continue;
3545                         }
3546
3547                         $exceptions = [];
3548                         $imageDBkey = false;
3549                         foreach ( $m[1] as $i => $titleText ) {
3550                                 $title = Title::newFromText( $titleText );
3551                                 if ( !is_null( $title ) ) {
3552                                         if ( $i == 0 ) {
3553                                                 $imageDBkey = $title->getDBkey();
3554                                         } else {
3555                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3556                                         }
3557                                 }
3558                         }
3559
3560                         if ( $imageDBkey !== false ) {
3561                                 $badImages[$imageDBkey] = $exceptions;
3562                         }
3563                 }
3564                 $cache->set( $key, $badImages, 60 );
3565         }
3566
3567         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3568         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3569
3570         return $bad;
3571 }
3572
3573 /**
3574  * Determine whether the client at a given source IP is likely to be able to
3575  * access the wiki via HTTPS.
3576  *
3577  * @param string $ip The IPv4/6 address in the normal human-readable form
3578  * @return bool
3579  */
3580 function wfCanIPUseHTTPS( $ip ) {
3581         $canDo = true;
3582         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3583         return !!$canDo;
3584 }
3585
3586 /**
3587  * Determine input string is represents as infinity
3588  *
3589  * @param string $str The string to determine
3590  * @return bool
3591  * @since 1.25
3592  */
3593 function wfIsInfinity( $str ) {
3594         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3595         return in_array( $str, $infinityValues );
3596 }
3597
3598 /**
3599  * Returns true if these thumbnail parameters match one that MediaWiki
3600  * requests from file description pages and/or parser output.
3601  *
3602  * $params is considered non-standard if they involve a non-standard
3603  * width or any non-default parameters aside from width and page number.
3604  * The number of possible files with standard parameters is far less than
3605  * that of all combinations; rate-limiting for them can thus be more generious.
3606  *
3607  * @param File $file
3608  * @param array $params
3609  * @return bool
3610  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3611  */
3612 function wfThumbIsStandard( File $file, array $params ) {
3613         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3614
3615         $multipliers = [ 1 ];
3616         if ( $wgResponsiveImages ) {
3617                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3618                 // @see Linker::processResponsiveImages
3619                 $multipliers[] = 1.5;
3620                 $multipliers[] = 2;
3621         }
3622
3623         $handler = $file->getHandler();
3624         if ( !$handler || !isset( $params['width'] ) ) {
3625                 return false;
3626         }
3627
3628         $basicParams = [];
3629         if ( isset( $params['page'] ) ) {
3630                 $basicParams['page'] = $params['page'];
3631         }
3632
3633         $thumbLimits = [];
3634         $imageLimits = [];
3635         // Expand limits to account for multipliers
3636         foreach ( $multipliers as $multiplier ) {
3637                 $thumbLimits = array_merge( $thumbLimits, array_map(
3638                         function ( $width ) use ( $multiplier ) {
3639                                 return round( $width * $multiplier );
3640                         }, $wgThumbLimits )
3641                 );
3642                 $imageLimits = array_merge( $imageLimits, array_map(
3643                         function ( $pair ) use ( $multiplier ) {
3644                                 return [
3645                                         round( $pair[0] * $multiplier ),
3646                                         round( $pair[1] * $multiplier ),
3647                                 ];
3648                         }, $wgImageLimits )
3649                 );
3650         }
3651
3652         // Check if the width matches one of $wgThumbLimits
3653         if ( in_array( $params['width'], $thumbLimits ) ) {
3654                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3655                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3656                 $handler->normaliseParams( $file, $normalParams );
3657         } else {
3658                 // If not, then check if the width matchs one of $wgImageLimits
3659                 $match = false;
3660                 foreach ( $imageLimits as $pair ) {
3661                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3662                         // Decide whether the thumbnail should be scaled on width or height.
3663                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3664                         $handler->normaliseParams( $file, $normalParams );
3665                         // Check if this standard thumbnail size maps to the given width
3666                         if ( $normalParams['width'] == $params['width'] ) {
3667                                 $match = true;
3668                                 break;
3669                         }
3670                 }
3671                 if ( !$match ) {
3672                         return false; // not standard for description pages
3673                 }
3674         }
3675
3676         // Check that the given values for non-page, non-width, params are just defaults
3677         foreach ( $params as $key => $value ) {
3678                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3679                         return false;
3680                 }
3681         }
3682
3683         return true;
3684 }
3685
3686 /**
3687  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3688  *
3689  * Values that exist in both values will be combined with += (all values of the array
3690  * of $newValues will be added to the values of the array of $baseArray, while values,
3691  * that exists in both, the value of $baseArray will be used).
3692  *
3693  * @param array $baseArray The array where you want to add the values of $newValues to
3694  * @param array $newValues An array with new values
3695  * @return array The combined array
3696  * @since 1.26
3697  */
3698 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3699         // First merge items that are in both arrays
3700         foreach ( $baseArray as $name => &$groupVal ) {
3701                 if ( isset( $newValues[$name] ) ) {
3702                         $groupVal += $newValues[$name];
3703                 }
3704         }
3705         // Now add items that didn't exist yet
3706         $baseArray += $newValues;
3707
3708         return $baseArray;
3709 }