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 // http://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  * @todo document
1629  * @todo FIXME: We may want to blacklist some broken browsers
1630  *
1631  * @param bool $force
1632  * @return bool Whereas client accept gzip compression
1633  */
1634 function wfClientAcceptsGzip( $force = false ) {
1635         static $result = null;
1636         if ( $result === null || $force ) {
1637                 $result = false;
1638                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1639                         # @todo FIXME: We may want to blacklist some broken browsers
1640                         $m = [];
1641                         if ( preg_match(
1642                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1643                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1644                                         $m
1645                                 )
1646                         ) {
1647                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1648                                         $result = false;
1649                                         return $result;
1650                                 }
1651                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1652                                 $result = true;
1653                         }
1654                 }
1655         }
1656         return $result;
1657 }
1658
1659 /**
1660  * Escapes the given text so that it may be output using addWikiText()
1661  * without any linking, formatting, etc. making its way through. This
1662  * is achieved by substituting certain characters with HTML entities.
1663  * As required by the callers, "<nowiki>" is not used.
1664  *
1665  * @param string $text Text to be escaped
1666  * @return string
1667  */
1668 function wfEscapeWikiText( $text ) {
1669         global $wgEnableMagicLinks;
1670         static $repl = null, $repl2 = null;
1671         if ( $repl === null ) {
1672                 $repl = [
1673                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1674                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1675                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1676                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1677                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1678                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1679                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1680                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1681                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1682                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1683                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1684                         '__' => '_&#95;', '://' => '&#58;//',
1685                 ];
1686
1687                 $magicLinks = array_keys( array_filter( $wgEnableMagicLinks ) );
1688                 // We have to catch everything "\s" matches in PCRE
1689                 foreach ( $magicLinks as $magic ) {
1690                         $repl["$magic "] = "$magic&#32;";
1691                         $repl["$magic\t"] = "$magic&#9;";
1692                         $repl["$magic\r"] = "$magic&#13;";
1693                         $repl["$magic\n"] = "$magic&#10;";
1694                         $repl["$magic\f"] = "$magic&#12;";
1695                 }
1696
1697                 // And handle protocols that don't use "://"
1698                 global $wgUrlProtocols;
1699                 $repl2 = [];
1700                 foreach ( $wgUrlProtocols as $prot ) {
1701                         if ( substr( $prot, -1 ) === ':' ) {
1702                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1703                         }
1704                 }
1705                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1706         }
1707         $text = substr( strtr( "\n$text", $repl ), 1 );
1708         $text = preg_replace( $repl2, '$1&#58;', $text );
1709         return $text;
1710 }
1711
1712 /**
1713  * Sets dest to source and returns the original value of dest
1714  * If source is NULL, it just returns the value, it doesn't set the variable
1715  * If force is true, it will set the value even if source is NULL
1716  *
1717  * @param mixed $dest
1718  * @param mixed $source
1719  * @param bool $force
1720  * @return mixed
1721  */
1722 function wfSetVar( &$dest, $source, $force = false ) {
1723         $temp = $dest;
1724         if ( !is_null( $source ) || $force ) {
1725                 $dest = $source;
1726         }
1727         return $temp;
1728 }
1729
1730 /**
1731  * As for wfSetVar except setting a bit
1732  *
1733  * @param int $dest
1734  * @param int $bit
1735  * @param bool $state
1736  *
1737  * @return bool
1738  */
1739 function wfSetBit( &$dest, $bit, $state = true ) {
1740         $temp = (bool)( $dest & $bit );
1741         if ( !is_null( $state ) ) {
1742                 if ( $state ) {
1743                         $dest |= $bit;
1744                 } else {
1745                         $dest &= ~$bit;
1746                 }
1747         }
1748         return $temp;
1749 }
1750
1751 /**
1752  * A wrapper around the PHP function var_export().
1753  * Either print it or add it to the regular output ($wgOut).
1754  *
1755  * @param mixed $var A PHP variable to dump.
1756  */
1757 function wfVarDump( $var ) {
1758         global $wgOut;
1759         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1760         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1761                 print $s;
1762         } else {
1763                 $wgOut->addHTML( $s );
1764         }
1765 }
1766
1767 /**
1768  * Provide a simple HTTP error.
1769  *
1770  * @param int|string $code
1771  * @param string $label
1772  * @param string $desc
1773  */
1774 function wfHttpError( $code, $label, $desc ) {
1775         global $wgOut;
1776         HttpStatus::header( $code );
1777         if ( $wgOut ) {
1778                 $wgOut->disable();
1779                 $wgOut->sendCacheControl();
1780         }
1781
1782         header( 'Content-type: text/html; charset=utf-8' );
1783         print '<!DOCTYPE html>' .
1784                 '<html><head><title>' .
1785                 htmlspecialchars( $label ) .
1786                 '</title></head><body><h1>' .
1787                 htmlspecialchars( $label ) .
1788                 '</h1><p>' .
1789                 nl2br( htmlspecialchars( $desc ) ) .
1790                 "</p></body></html>\n";
1791 }
1792
1793 /**
1794  * Clear away any user-level output buffers, discarding contents.
1795  *
1796  * Suitable for 'starting afresh', for instance when streaming
1797  * relatively large amounts of data without buffering, or wanting to
1798  * output image files without ob_gzhandler's compression.
1799  *
1800  * The optional $resetGzipEncoding parameter controls suppression of
1801  * the Content-Encoding header sent by ob_gzhandler; by default it
1802  * is left. See comments for wfClearOutputBuffers() for why it would
1803  * be used.
1804  *
1805  * Note that some PHP configuration options may add output buffer
1806  * layers which cannot be removed; these are left in place.
1807  *
1808  * @param bool $resetGzipEncoding
1809  */
1810 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1811         if ( $resetGzipEncoding ) {
1812                 // Suppress Content-Encoding and Content-Length
1813                 // headers from 1.10+s wfOutputHandler
1814                 global $wgDisableOutputCompression;
1815                 $wgDisableOutputCompression = true;
1816         }
1817         while ( $status = ob_get_status() ) {
1818                 if ( isset( $status['flags'] ) ) {
1819                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1820                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1821                 } elseif ( isset( $status['del'] ) ) {
1822                         $deleteable = $status['del'];
1823                 } else {
1824                         // Guess that any PHP-internal setting can't be removed.
1825                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1826                 }
1827                 if ( !$deleteable ) {
1828                         // Give up, and hope the result doesn't break
1829                         // output behavior.
1830                         break;
1831                 }
1832                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1833                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1834                         break;
1835                 }
1836                 if ( !ob_end_clean() ) {
1837                         // Could not remove output buffer handler; abort now
1838                         // to avoid getting in some kind of infinite loop.
1839                         break;
1840                 }
1841                 if ( $resetGzipEncoding ) {
1842                         if ( $status['name'] == 'ob_gzhandler' ) {
1843                                 // Reset the 'Content-Encoding' field set by this handler
1844                                 // so we can start fresh.
1845                                 header_remove( 'Content-Encoding' );
1846                                 break;
1847                         }
1848                 }
1849         }
1850 }
1851
1852 /**
1853  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1854  *
1855  * Clear away output buffers, but keep the Content-Encoding header
1856  * produced by ob_gzhandler, if any.
1857  *
1858  * This should be used for HTTP 304 responses, where you need to
1859  * preserve the Content-Encoding header of the real result, but
1860  * also need to suppress the output of ob_gzhandler to keep to spec
1861  * and avoid breaking Firefox in rare cases where the headers and
1862  * body are broken over two packets.
1863  */
1864 function wfClearOutputBuffers() {
1865         wfResetOutputBuffers( false );
1866 }
1867
1868 /**
1869  * Converts an Accept-* header into an array mapping string values to quality
1870  * factors
1871  *
1872  * @param string $accept
1873  * @param string $def Default
1874  * @return float[] Associative array of string => float pairs
1875  */
1876 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1877         # No arg means accept anything (per HTTP spec)
1878         if ( !$accept ) {
1879                 return [ $def => 1.0 ];
1880         }
1881
1882         $prefs = [];
1883
1884         $parts = explode( ',', $accept );
1885
1886         foreach ( $parts as $part ) {
1887                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1888                 $values = explode( ';', trim( $part ) );
1889                 $match = [];
1890                 if ( count( $values ) == 1 ) {
1891                         $prefs[$values[0]] = 1.0;
1892                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1893                         $prefs[$values[0]] = floatval( $match[1] );
1894                 }
1895         }
1896
1897         return $prefs;
1898 }
1899
1900 /**
1901  * Checks if a given MIME type matches any of the keys in the given
1902  * array. Basic wildcards are accepted in the array keys.
1903  *
1904  * Returns the matching MIME type (or wildcard) if a match, otherwise
1905  * NULL if no match.
1906  *
1907  * @param string $type
1908  * @param array $avail
1909  * @return string
1910  * @private
1911  */
1912 function mimeTypeMatch( $type, $avail ) {
1913         if ( array_key_exists( $type, $avail ) ) {
1914                 return $type;
1915         } else {
1916                 $mainType = explode( '/', $type )[0];
1917                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1918                         return "$mainType/*";
1919                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1920                         return '*/*';
1921                 } else {
1922                         return null;
1923                 }
1924         }
1925 }
1926
1927 /**
1928  * Returns the 'best' match between a client's requested internet media types
1929  * and the server's list of available types. Each list should be an associative
1930  * array of type to preference (preference is a float between 0.0 and 1.0).
1931  * Wildcards in the types are acceptable.
1932  *
1933  * @param array $cprefs Client's acceptable type list
1934  * @param array $sprefs Server's offered types
1935  * @return string
1936  *
1937  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1938  * XXX: generalize to negotiate other stuff
1939  */
1940 function wfNegotiateType( $cprefs, $sprefs ) {
1941         $combine = [];
1942
1943         foreach ( array_keys( $sprefs ) as $type ) {
1944                 $subType = explode( '/', $type )[1];
1945                 if ( $subType != '*' ) {
1946                         $ckey = mimeTypeMatch( $type, $cprefs );
1947                         if ( $ckey ) {
1948                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1949                         }
1950                 }
1951         }
1952
1953         foreach ( array_keys( $cprefs ) as $type ) {
1954                 $subType = explode( '/', $type )[1];
1955                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1956                         $skey = mimeTypeMatch( $type, $sprefs );
1957                         if ( $skey ) {
1958                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1959                         }
1960                 }
1961         }
1962
1963         $bestq = 0;
1964         $besttype = null;
1965
1966         foreach ( array_keys( $combine ) as $type ) {
1967                 if ( $combine[$type] > $bestq ) {
1968                         $besttype = $type;
1969                         $bestq = $combine[$type];
1970                 }
1971         }
1972
1973         return $besttype;
1974 }
1975
1976 /**
1977  * Reference-counted warning suppression
1978  *
1979  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
1980  * @param bool $end
1981  */
1982 function wfSuppressWarnings( $end = false ) {
1983         MediaWiki\suppressWarnings( $end );
1984 }
1985
1986 /**
1987  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
1988  * Restore error level to previous value
1989  */
1990 function wfRestoreWarnings() {
1991         MediaWiki\suppressWarnings( true );
1992 }
1993
1994 # Autodetect, convert and provide timestamps of various types
1995
1996 require_once __DIR__ . '/libs/time/defines.php';
1997
1998 /**
1999  * Get a timestamp string in one of various formats
2000  *
2001  * @param mixed $outputtype A timestamp in one of the supported formats, the
2002  *   function will autodetect which format is supplied and act accordingly.
2003  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2004  * @return string|bool String / false The same date in the format specified in $outputtype or false
2005  */
2006 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2007         $ret = MWTimestamp::convert( $outputtype, $ts );
2008         if ( $ret === false ) {
2009                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2010         }
2011         return $ret;
2012 }
2013
2014 /**
2015  * Return a formatted timestamp, or null if input is null.
2016  * For dealing with nullable timestamp columns in the database.
2017  *
2018  * @param int $outputtype
2019  * @param string $ts
2020  * @return string
2021  */
2022 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2023         if ( is_null( $ts ) ) {
2024                 return null;
2025         } else {
2026                 return wfTimestamp( $outputtype, $ts );
2027         }
2028 }
2029
2030 /**
2031  * Convenience function; returns MediaWiki timestamp for the present time.
2032  *
2033  * @return string
2034  */
2035 function wfTimestampNow() {
2036         # return NOW
2037         return MWTimestamp::now( TS_MW );
2038 }
2039
2040 /**
2041  * Check if the operating system is Windows
2042  *
2043  * @return bool True if it's Windows, false otherwise.
2044  */
2045 function wfIsWindows() {
2046         static $isWindows = null;
2047         if ( $isWindows === null ) {
2048                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2049         }
2050         return $isWindows;
2051 }
2052
2053 /**
2054  * Check if we are running under HHVM
2055  *
2056  * @return bool
2057  */
2058 function wfIsHHVM() {
2059         return defined( 'HHVM_VERSION' );
2060 }
2061
2062 /**
2063  * Tries to get the system directory for temporary files. First
2064  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2065  * environment variables are then checked in sequence, then
2066  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2067  *
2068  * NOTE: When possible, use instead the tmpfile() function to create
2069  * temporary files to avoid race conditions on file creation, etc.
2070  *
2071  * @return string
2072  */
2073 function wfTempDir() {
2074         global $wgTmpDirectory;
2075
2076         if ( $wgTmpDirectory !== false ) {
2077                 return $wgTmpDirectory;
2078         }
2079
2080         return TempFSFile::getUsableTempDirectory();
2081 }
2082
2083 /**
2084  * Make directory, and make all parent directories if they don't exist
2085  *
2086  * @param string $dir Full path to directory to create
2087  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2088  * @param string $caller Optional caller param for debugging.
2089  * @throws MWException
2090  * @return bool
2091  */
2092 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2093         global $wgDirectoryMode;
2094
2095         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2096                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2097         }
2098
2099         if ( !is_null( $caller ) ) {
2100                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2101         }
2102
2103         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2104                 return true;
2105         }
2106
2107         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
2108
2109         if ( is_null( $mode ) ) {
2110                 $mode = $wgDirectoryMode;
2111         }
2112
2113         // Turn off the normal warning, we're doing our own below
2114         MediaWiki\suppressWarnings();
2115         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2116         MediaWiki\restoreWarnings();
2117
2118         if ( !$ok ) {
2119                 // directory may have been created on another request since we last checked
2120                 if ( is_dir( $dir ) ) {
2121                         return true;
2122                 }
2123
2124                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2125                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2126         }
2127         return $ok;
2128 }
2129
2130 /**
2131  * Remove a directory and all its content.
2132  * Does not hide error.
2133  * @param string $dir
2134  */
2135 function wfRecursiveRemoveDir( $dir ) {
2136         wfDebug( __FUNCTION__ . "( $dir )\n" );
2137         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2138         if ( is_dir( $dir ) ) {
2139                 $objects = scandir( $dir );
2140                 foreach ( $objects as $object ) {
2141                         if ( $object != "." && $object != ".." ) {
2142                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2143                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2144                                 } else {
2145                                         unlink( $dir . '/' . $object );
2146                                 }
2147                         }
2148                 }
2149                 reset( $objects );
2150                 rmdir( $dir );
2151         }
2152 }
2153
2154 /**
2155  * @param int $nr The number to format
2156  * @param int $acc The number of digits after the decimal point, default 2
2157  * @param bool $round Whether or not to round the value, default true
2158  * @return string
2159  */
2160 function wfPercent( $nr, $acc = 2, $round = true ) {
2161         $ret = sprintf( "%.${acc}f", $nr );
2162         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2163 }
2164
2165 /**
2166  * Safety wrapper around ini_get() for boolean settings.
2167  * The values returned from ini_get() are pre-normalized for settings
2168  * set via php.ini or php_flag/php_admin_flag... but *not*
2169  * for those set via php_value/php_admin_value.
2170  *
2171  * It's fairly common for people to use php_value instead of php_flag,
2172  * which can leave you with an 'off' setting giving a false positive
2173  * for code that just takes the ini_get() return value as a boolean.
2174  *
2175  * To make things extra interesting, setting via php_value accepts
2176  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2177  * Unrecognized values go false... again opposite PHP's own coercion
2178  * from string to bool.
2179  *
2180  * Luckily, 'properly' set settings will always come back as '0' or '1',
2181  * so we only have to worry about them and the 'improper' settings.
2182  *
2183  * I frickin' hate PHP... :P
2184  *
2185  * @param string $setting
2186  * @return bool
2187  */
2188 function wfIniGetBool( $setting ) {
2189         $val = strtolower( ini_get( $setting ) );
2190         // 'on' and 'true' can't have whitespace around them, but '1' can.
2191         return $val == 'on'
2192                 || $val == 'true'
2193                 || $val == 'yes'
2194                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2195 }
2196
2197 /**
2198  * Version of escapeshellarg() that works better on Windows.
2199  *
2200  * Originally, this fixed the incorrect use of single quotes on Windows
2201  * (https://bugs.php.net/bug.php?id=26285) and the locale problems on Linux in
2202  * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
2203  *
2204  * @param string ... strings to escape and glue together, or a single array of strings parameter
2205  * @return string
2206  */
2207 function wfEscapeShellArg( /*...*/ ) {
2208         wfInitShellLocale();
2209
2210         $args = func_get_args();
2211         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2212                 // If only one argument has been passed, and that argument is an array,
2213                 // treat it as a list of arguments
2214                 $args = reset( $args );
2215         }
2216
2217         $first = true;
2218         $retVal = '';
2219         foreach ( $args as $arg ) {
2220                 if ( !$first ) {
2221                         $retVal .= ' ';
2222                 } else {
2223                         $first = false;
2224                 }
2225
2226                 if ( wfIsWindows() ) {
2227                         // Escaping for an MSVC-style command line parser and CMD.EXE
2228                         // @codingStandardsIgnoreStart For long URLs
2229                         // Refs:
2230                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2231                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2232                         //  * T15518
2233                         //  * CR r63214
2234                         // Double the backslashes before any double quotes. Escape the double quotes.
2235                         // @codingStandardsIgnoreEnd
2236                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2237                         $arg = '';
2238                         $iteration = 0;
2239                         foreach ( $tokens as $token ) {
2240                                 if ( $iteration % 2 == 1 ) {
2241                                         // Delimiter, a double quote preceded by zero or more slashes
2242                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2243                                 } elseif ( $iteration % 4 == 2 ) {
2244                                         // ^ in $token will be outside quotes, need to be escaped
2245                                         $arg .= str_replace( '^', '^^', $token );
2246                                 } else { // $iteration % 4 == 0
2247                                         // ^ in $token will appear inside double quotes, so leave as is
2248                                         $arg .= $token;
2249                                 }
2250                                 $iteration++;
2251                         }
2252                         // Double the backslashes before the end of the string, because
2253                         // we will soon add a quote
2254                         $m = [];
2255                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2256                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2257                         }
2258
2259                         // Add surrounding quotes
2260                         $retVal .= '"' . $arg . '"';
2261                 } else {
2262                         $retVal .= escapeshellarg( $arg );
2263                 }
2264         }
2265         return $retVal;
2266 }
2267
2268 /**
2269  * Check if wfShellExec() is effectively disabled via php.ini config
2270  *
2271  * @return bool|string False or 'disabled'
2272  * @since 1.22
2273  */
2274 function wfShellExecDisabled() {
2275         static $disabled = null;
2276         if ( is_null( $disabled ) ) {
2277                 if ( !function_exists( 'proc_open' ) ) {
2278                         wfDebug( "proc_open() is disabled\n" );
2279                         $disabled = 'disabled';
2280                 } else {
2281                         $disabled = false;
2282                 }
2283         }
2284         return $disabled;
2285 }
2286
2287 /**
2288  * Execute a shell command, with time and memory limits mirrored from the PHP
2289  * configuration if supported.
2290  *
2291  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2292  *   or an array of unescaped arguments, in which case each value will be escaped
2293  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2294  * @param null|mixed &$retval Optional, will receive the program's exit code.
2295  *   (non-zero is usually failure). If there is an error from
2296  *   read, select, or proc_open(), this will be set to -1.
2297  * @param array $environ Optional environment variables which should be
2298  *   added to the executed command environment.
2299  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2300  *   this overwrites the global wgMaxShell* limits.
2301  * @param array $options Array of options:
2302  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2303  *     including errors from limit.sh
2304  *   - profileMethod: By default this function will profile based on the calling
2305  *     method. Set this to a string for an alternative method to profile from
2306  *
2307  * @return string Collected stdout as a string
2308  */
2309 function wfShellExec( $cmd, &$retval = null, $environ = [],
2310         $limits = [], $options = []
2311 ) {
2312         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2313                 $wgMaxShellWallClockTime, $wgShellCgroup;
2314
2315         $disabled = wfShellExecDisabled();
2316         if ( $disabled ) {
2317                 $retval = 1;
2318                 return 'Unable to run external programs, proc_open() is disabled.';
2319         }
2320
2321         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2322         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2323
2324         wfInitShellLocale();
2325
2326         $envcmd = '';
2327         foreach ( $environ as $k => $v ) {
2328                 if ( wfIsWindows() ) {
2329                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2330                          * appear in the environment variable, so we must use carat escaping as documented in
2331                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2332                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2333                          * are listed there but doesn't appear to need it.
2334                          */
2335                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2336                 } else {
2337                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2338                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2339                          */
2340                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2341                 }
2342         }
2343         if ( is_array( $cmd ) ) {
2344                 $cmd = wfEscapeShellArg( $cmd );
2345         }
2346
2347         $cmd = $envcmd . $cmd;
2348
2349         $useLogPipe = false;
2350         if ( is_executable( '/bin/bash' ) ) {
2351                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2352                 if ( isset( $limits['walltime'] ) ) {
2353                         $wallTime = intval( $limits['walltime'] );
2354                 } elseif ( isset( $limits['time'] ) ) {
2355                         $wallTime = $time;
2356                 } else {
2357                         $wallTime = intval( $wgMaxShellWallClockTime );
2358                 }
2359                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2360                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2361
2362                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2363                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2364                                 escapeshellarg( $cmd ) . ' ' .
2365                                 escapeshellarg(
2366                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2367                                         "MW_CPU_LIMIT=$time; " .
2368                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2369                                         "MW_MEM_LIMIT=$mem; " .
2370                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2371                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2372                                         "MW_USE_LOG_PIPE=yes"
2373                                 );
2374                         $useLogPipe = true;
2375                 } elseif ( $includeStderr ) {
2376                         $cmd .= ' 2>&1';
2377                 }
2378         } elseif ( $includeStderr ) {
2379                 $cmd .= ' 2>&1';
2380         }
2381         wfDebug( "wfShellExec: $cmd\n" );
2382
2383         // Don't try to execute commands that exceed Linux's MAX_ARG_STRLEN.
2384         // Other platforms may be more accomodating, but we don't want to be
2385         // accomodating, because very long commands probably include user
2386         // input. See T129506.
2387         if ( strlen( $cmd ) > SHELL_MAX_ARG_STRLEN ) {
2388                 throw new Exception( __METHOD__ .
2389                         '(): total length of $cmd must not exceed SHELL_MAX_ARG_STRLEN' );
2390         }
2391
2392         $desc = [
2393                 0 => [ 'file', 'php://stdin', 'r' ],
2394                 1 => [ 'pipe', 'w' ],
2395                 2 => [ 'file', 'php://stderr', 'w' ] ];
2396         if ( $useLogPipe ) {
2397                 $desc[3] = [ 'pipe', 'w' ];
2398         }
2399         $pipes = null;
2400         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2401         $proc = proc_open( $cmd, $desc, $pipes );
2402         if ( !$proc ) {
2403                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2404                 $retval = -1;
2405                 return '';
2406         }
2407         $outBuffer = $logBuffer = '';
2408         $emptyArray = [];
2409         $status = false;
2410         $logMsg = false;
2411
2412         /* According to the documentation, it is possible for stream_select()
2413          * to fail due to EINTR. I haven't managed to induce this in testing
2414          * despite sending various signals. If it did happen, the error
2415          * message would take the form:
2416          *
2417          * stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2418          *
2419          * where [4] is the value of the macro EINTR and "Interrupted system
2420          * call" is string which according to the Linux manual is "possibly"
2421          * localised according to LC_MESSAGES.
2422          */
2423         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2424         $eintrMessage = "stream_select(): unable to select [$eintr]";
2425
2426         $running = true;
2427         $timeout = null;
2428         $numReadyPipes = 0;
2429
2430         while ( $running === true || $numReadyPipes !== 0 ) {
2431                 if ( $running ) {
2432                         $status = proc_get_status( $proc );
2433                         // If the process has terminated, switch to nonblocking selects
2434                         // for getting any data still waiting to be read.
2435                         if ( !$status['running'] ) {
2436                                 $running = false;
2437                                 $timeout = 0;
2438                         }
2439                 }
2440
2441                 $readyPipes = $pipes;
2442
2443                 // Clear last error
2444                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2445                 @trigger_error( '' );
2446                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2447                 if ( $numReadyPipes === false ) {
2448                         // @codingStandardsIgnoreEnd
2449                         $error = error_get_last();
2450                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2451                                 continue;
2452                         } else {
2453                                 trigger_error( $error['message'], E_USER_WARNING );
2454                                 $logMsg = $error['message'];
2455                                 break;
2456                         }
2457                 }
2458                 foreach ( $readyPipes as $fd => $pipe ) {
2459                         $block = fread( $pipe, 65536 );
2460                         if ( $block === '' ) {
2461                                 // End of file
2462                                 fclose( $pipes[$fd] );
2463                                 unset( $pipes[$fd] );
2464                                 if ( !$pipes ) {
2465                                         break 2;
2466                                 }
2467                         } elseif ( $block === false ) {
2468                                 // Read error
2469                                 $logMsg = "Error reading from pipe";
2470                                 break 2;
2471                         } elseif ( $fd == 1 ) {
2472                                 // From stdout
2473                                 $outBuffer .= $block;
2474                         } elseif ( $fd == 3 ) {
2475                                 // From log FD
2476                                 $logBuffer .= $block;
2477                                 if ( strpos( $block, "\n" ) !== false ) {
2478                                         $lines = explode( "\n", $logBuffer );
2479                                         $logBuffer = array_pop( $lines );
2480                                         foreach ( $lines as $line ) {
2481                                                 wfDebugLog( 'exec', $line );
2482                                         }
2483                                 }
2484                         }
2485                 }
2486         }
2487
2488         foreach ( $pipes as $pipe ) {
2489                 fclose( $pipe );
2490         }
2491
2492         // Use the status previously collected if possible, since proc_get_status()
2493         // just calls waitpid() which will not return anything useful the second time.
2494         if ( $running ) {
2495                 $status = proc_get_status( $proc );
2496         }
2497
2498         if ( $logMsg !== false ) {
2499                 // Read/select error
2500                 $retval = -1;
2501                 proc_close( $proc );
2502         } elseif ( $status['signaled'] ) {
2503                 $logMsg = "Exited with signal {$status['termsig']}";
2504                 $retval = 128 + $status['termsig'];
2505                 proc_close( $proc );
2506         } else {
2507                 if ( $status['running'] ) {
2508                         $retval = proc_close( $proc );
2509                 } else {
2510                         $retval = $status['exitcode'];
2511                         proc_close( $proc );
2512                 }
2513                 if ( $retval == 127 ) {
2514                         $logMsg = "Possibly missing executable file";
2515                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2516                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2517                 }
2518         }
2519
2520         if ( $logMsg !== false ) {
2521                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2522         }
2523
2524         return $outBuffer;
2525 }
2526
2527 /**
2528  * Execute a shell command, returning both stdout and stderr. Convenience
2529  * function, as all the arguments to wfShellExec can become unwieldy.
2530  *
2531  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2532  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2533  *   or an array of unescaped arguments, in which case each value will be escaped
2534  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2535  * @param null|mixed &$retval Optional, will receive the program's exit code.
2536  *   (non-zero is usually failure)
2537  * @param array $environ Optional environment variables which should be
2538  *   added to the executed command environment.
2539  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2540  *   this overwrites the global wgMaxShell* limits.
2541  * @return string Collected stdout and stderr as a string
2542  */
2543 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2544         return wfShellExec( $cmd, $retval, $environ, $limits,
2545                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2546 }
2547
2548 /**
2549  * Workaround for http://bugs.php.net/bug.php?id=45132
2550  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2551  */
2552 function wfInitShellLocale() {
2553         static $done = false;
2554         if ( $done ) {
2555                 return;
2556         }
2557         $done = true;
2558         global $wgShellLocale;
2559         putenv( "LC_CTYPE=$wgShellLocale" );
2560         setlocale( LC_CTYPE, $wgShellLocale );
2561 }
2562
2563 /**
2564  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2565  * Note that $parameters should be a flat array and an option with an argument
2566  * should consist of two consecutive items in the array (do not use "--option value").
2567  *
2568  * @param string $script MediaWiki cli script path
2569  * @param array $parameters Arguments and options to the script
2570  * @param array $options Associative array of options:
2571  *              'php': The path to the php executable
2572  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2573  * @return string
2574  */
2575 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2576         global $wgPhpCli;
2577         // Give site config file a chance to run the script in a wrapper.
2578         // The caller may likely want to call wfBasename() on $script.
2579         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2580         $cmd = isset( $options['php'] ) ? [ $options['php'] ] : [ $wgPhpCli ];
2581         if ( isset( $options['wrapper'] ) ) {
2582                 $cmd[] = $options['wrapper'];
2583         }
2584         $cmd[] = $script;
2585         // Escape each parameter for shell
2586         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
2587 }
2588
2589 /**
2590  * wfMerge attempts to merge differences between three texts.
2591  * Returns true for a clean merge and false for failure or a conflict.
2592  *
2593  * @param string $old
2594  * @param string $mine
2595  * @param string $yours
2596  * @param string $result
2597  * @return bool
2598  */
2599 function wfMerge( $old, $mine, $yours, &$result ) {
2600         global $wgDiff3;
2601
2602         # This check may also protect against code injection in
2603         # case of broken installations.
2604         MediaWiki\suppressWarnings();
2605         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2606         MediaWiki\restoreWarnings();
2607
2608         if ( !$haveDiff3 ) {
2609                 wfDebug( "diff3 not found\n" );
2610                 return false;
2611         }
2612
2613         # Make temporary files
2614         $td = wfTempDir();
2615         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2616         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2617         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2618
2619         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2620         #       a newline character. To avoid this, we normalize the trailing whitespace before
2621         #       creating the diff.
2622
2623         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2624         fclose( $oldtextFile );
2625         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2626         fclose( $mytextFile );
2627         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2628         fclose( $yourtextFile );
2629
2630         # Check for a conflict
2631         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
2632                 $oldtextName, $yourtextName );
2633         $handle = popen( $cmd, 'r' );
2634
2635         if ( fgets( $handle, 1024 ) ) {
2636                 $conflict = true;
2637         } else {
2638                 $conflict = false;
2639         }
2640         pclose( $handle );
2641
2642         # Merge differences
2643         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2644                 $oldtextName, $yourtextName );
2645         $handle = popen( $cmd, 'r' );
2646         $result = '';
2647         do {
2648                 $data = fread( $handle, 8192 );
2649                 if ( strlen( $data ) == 0 ) {
2650                         break;
2651                 }
2652                 $result .= $data;
2653         } while ( true );
2654         pclose( $handle );
2655         unlink( $mytextName );
2656         unlink( $oldtextName );
2657         unlink( $yourtextName );
2658
2659         if ( $result === '' && $old !== '' && !$conflict ) {
2660                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2661                 $conflict = true;
2662         }
2663         return !$conflict;
2664 }
2665
2666 /**
2667  * Returns unified plain-text diff of two texts.
2668  * "Useful" for machine processing of diffs.
2669  *
2670  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2671  *
2672  * @param string $before The text before the changes.
2673  * @param string $after The text after the changes.
2674  * @param string $params Command-line options for the diff command.
2675  * @return string Unified diff of $before and $after
2676  */
2677 function wfDiff( $before, $after, $params = '-u' ) {
2678         if ( $before == $after ) {
2679                 return '';
2680         }
2681
2682         global $wgDiff;
2683         MediaWiki\suppressWarnings();
2684         $haveDiff = $wgDiff && file_exists( $wgDiff );
2685         MediaWiki\restoreWarnings();
2686
2687         # This check may also protect against code injection in
2688         # case of broken installations.
2689         if ( !$haveDiff ) {
2690                 wfDebug( "diff executable not found\n" );
2691                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2692                 $format = new UnifiedDiffFormatter();
2693                 return $format->format( $diffs );
2694         }
2695
2696         # Make temporary files
2697         $td = wfTempDir();
2698         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2699         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2700
2701         fwrite( $oldtextFile, $before );
2702         fclose( $oldtextFile );
2703         fwrite( $newtextFile, $after );
2704         fclose( $newtextFile );
2705
2706         // Get the diff of the two files
2707         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2708
2709         $h = popen( $cmd, 'r' );
2710         if ( !$h ) {
2711                 unlink( $oldtextName );
2712                 unlink( $newtextName );
2713                 throw new Exception( __METHOD__ . '(): popen() failed' );
2714         }
2715
2716         $diff = '';
2717
2718         do {
2719                 $data = fread( $h, 8192 );
2720                 if ( strlen( $data ) == 0 ) {
2721                         break;
2722                 }
2723                 $diff .= $data;
2724         } while ( true );
2725
2726         // Clean up
2727         pclose( $h );
2728         unlink( $oldtextName );
2729         unlink( $newtextName );
2730
2731         // Kill the --- and +++ lines. They're not useful.
2732         $diff_lines = explode( "\n", $diff );
2733         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2734                 unset( $diff_lines[0] );
2735         }
2736         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2737                 unset( $diff_lines[1] );
2738         }
2739
2740         $diff = implode( "\n", $diff_lines );
2741
2742         return $diff;
2743 }
2744
2745 /**
2746  * This function works like "use VERSION" in Perl, the program will die with a
2747  * backtrace if the current version of PHP is less than the version provided
2748  *
2749  * This is useful for extensions which due to their nature are not kept in sync
2750  * with releases, and might depend on other versions of PHP than the main code
2751  *
2752  * Note: PHP might die due to parsing errors in some cases before it ever
2753  *       manages to call this function, such is life
2754  *
2755  * @see perldoc -f use
2756  *
2757  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2758  * @throws MWException
2759  */
2760 function wfUsePHP( $req_ver ) {
2761         $php_ver = PHP_VERSION;
2762
2763         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2764                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2765         }
2766 }
2767
2768 /**
2769  * This function works like "use VERSION" in Perl except it checks the version
2770  * of MediaWiki, the program will die with a backtrace if the current version
2771  * of MediaWiki is less than the version provided.
2772  *
2773  * This is useful for extensions which due to their nature are not kept in sync
2774  * with releases
2775  *
2776  * Note: Due to the behavior of PHP's version_compare() which is used in this
2777  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2778  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2779  * targeted version number. For example if you wanted to allow any variation
2780  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2781  * not result in the same comparison due to the internal logic of
2782  * version_compare().
2783  *
2784  * @see perldoc -f use
2785  *
2786  * @deprecated since 1.26, use the "requires' property of extension.json
2787  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2788  * @throws MWException
2789  */
2790 function wfUseMW( $req_ver ) {
2791         global $wgVersion;
2792
2793         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2794                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2795         }
2796 }
2797
2798 /**
2799  * Return the final portion of a pathname.
2800  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2801  * http://bugs.php.net/bug.php?id=33898
2802  *
2803  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2804  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2805  *
2806  * @param string $path
2807  * @param string $suffix String to remove if present
2808  * @return string
2809  */
2810 function wfBaseName( $path, $suffix = '' ) {
2811         if ( $suffix == '' ) {
2812                 $encSuffix = '';
2813         } else {
2814                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2815         }
2816
2817         $matches = [];
2818         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2819                 return $matches[1];
2820         } else {
2821                 return '';
2822         }
2823 }
2824
2825 /**
2826  * Generate a relative path name to the given file.
2827  * May explode on non-matching case-insensitive paths,
2828  * funky symlinks, etc.
2829  *
2830  * @param string $path Absolute destination path including target filename
2831  * @param string $from Absolute source path, directory only
2832  * @return string
2833  */
2834 function wfRelativePath( $path, $from ) {
2835         // Normalize mixed input on Windows...
2836         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2837         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2838
2839         // Trim trailing slashes -- fix for drive root
2840         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2841         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2842
2843         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2844         $against = explode( DIRECTORY_SEPARATOR, $from );
2845
2846         if ( $pieces[0] !== $against[0] ) {
2847                 // Non-matching Windows drive letters?
2848                 // Return a full path.
2849                 return $path;
2850         }
2851
2852         // Trim off common prefix
2853         while ( count( $pieces ) && count( $against )
2854                 && $pieces[0] == $against[0] ) {
2855                 array_shift( $pieces );
2856                 array_shift( $against );
2857         }
2858
2859         // relative dots to bump us to the parent
2860         while ( count( $against ) ) {
2861                 array_unshift( $pieces, '..' );
2862                 array_shift( $against );
2863         }
2864
2865         array_push( $pieces, wfBaseName( $path ) );
2866
2867         return implode( DIRECTORY_SEPARATOR, $pieces );
2868 }
2869
2870 /**
2871  * Convert an arbitrarily-long digit string from one numeric base
2872  * to another, optionally zero-padding to a minimum column width.
2873  *
2874  * Supports base 2 through 36; digit values 10-36 are represented
2875  * as lowercase letters a-z. Input is case-insensitive.
2876  *
2877  * @deprecated since 1.27 Use Wikimedia\base_convert() directly
2878  *
2879  * @param string $input Input number
2880  * @param int $sourceBase Base of the input number
2881  * @param int $destBase Desired base of the output
2882  * @param int $pad Minimum number of digits in the output (pad with zeroes)
2883  * @param bool $lowercase Whether to output in lowercase or uppercase
2884  * @param string $engine Either "gmp", "bcmath", or "php"
2885  * @return string|bool The output number as a string, or false on error
2886  */
2887 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
2888         $lowercase = true, $engine = 'auto'
2889 ) {
2890         return Wikimedia\base_convert( $input, $sourceBase, $destBase, $pad, $lowercase, $engine );
2891 }
2892
2893 /**
2894  * @deprecated since 1.27, PHP's session generation isn't used with
2895  *  MediaWiki\Session\SessionManager
2896  */
2897 function wfFixSessionID() {
2898         wfDeprecated( __FUNCTION__, '1.27' );
2899 }
2900
2901 /**
2902  * Reset the session id
2903  *
2904  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2905  * @since 1.22
2906  */
2907 function wfResetSessionID() {
2908         wfDeprecated( __FUNCTION__, '1.27' );
2909         $session = SessionManager::getGlobalSession();
2910         $delay = $session->delaySave();
2911
2912         $session->resetId();
2913
2914         // Make sure a session is started, since that's what the old
2915         // wfResetSessionID() did.
2916         if ( session_id() !== $session->getId() ) {
2917                 wfSetupSession( $session->getId() );
2918         }
2919
2920         ScopedCallback::consume( $delay );
2921 }
2922
2923 /**
2924  * Initialise php session
2925  *
2926  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2927  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2928  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2929  *  here), then calling $session->persist().
2930  * @param bool|string $sessionId
2931  */
2932 function wfSetupSession( $sessionId = false ) {
2933         wfDeprecated( __FUNCTION__, '1.27' );
2934
2935         if ( $sessionId ) {
2936                 session_id( $sessionId );
2937         }
2938
2939         $session = SessionManager::getGlobalSession();
2940         $session->persist();
2941
2942         if ( session_id() !== $session->getId() ) {
2943                 session_id( $session->getId() );
2944         }
2945         MediaWiki\quietCall( 'session_start' );
2946 }
2947
2948 /**
2949  * Get an object from the precompiled serialized directory
2950  *
2951  * @param string $name
2952  * @return mixed The variable on success, false on failure
2953  */
2954 function wfGetPrecompiledData( $name ) {
2955         global $IP;
2956
2957         $file = "$IP/serialized/$name";
2958         if ( file_exists( $file ) ) {
2959                 $blob = file_get_contents( $file );
2960                 if ( $blob ) {
2961                         return unserialize( $blob );
2962                 }
2963         }
2964         return false;
2965 }
2966
2967 /**
2968  * Make a cache key for the local wiki.
2969  *
2970  * @param string $args,...
2971  * @return string
2972  */
2973 function wfMemcKey( /*...*/ ) {
2974         return call_user_func_array(
2975                 [ ObjectCache::getLocalClusterInstance(), 'makeKey' ],
2976                 func_get_args()
2977         );
2978 }
2979
2980 /**
2981  * Make a cache key for a foreign DB.
2982  *
2983  * Must match what wfMemcKey() would produce in context of the foreign wiki.
2984  *
2985  * @param string $db
2986  * @param string $prefix
2987  * @param string $args,...
2988  * @return string
2989  */
2990 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
2991         $args = array_slice( func_get_args(), 2 );
2992         $keyspace = $prefix ? "$db-$prefix" : $db;
2993         return call_user_func_array(
2994                 [ ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ],
2995                 [ $keyspace, $args ]
2996         );
2997 }
2998
2999 /**
3000  * Make a cache key with database-agnostic prefix.
3001  *
3002  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3003  * instead. Must have a prefix as otherwise keys that use a database name
3004  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3005  *
3006  * @since 1.26
3007  * @param string $args,...
3008  * @return string
3009  */
3010 function wfGlobalCacheKey( /*...*/ ) {
3011         return call_user_func_array(
3012                 [ ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ],
3013                 func_get_args()
3014         );
3015 }
3016
3017 /**
3018  * Get an ASCII string identifying this wiki
3019  * This is used as a prefix in memcached keys
3020  *
3021  * @return string
3022  */
3023 function wfWikiID() {
3024         global $wgDBprefix, $wgDBname;
3025         if ( $wgDBprefix ) {
3026                 return "$wgDBname-$wgDBprefix";
3027         } else {
3028                 return $wgDBname;
3029         }
3030 }
3031
3032 /**
3033  * Split a wiki ID into DB name and table prefix
3034  *
3035  * @param string $wiki
3036  *
3037  * @return array
3038  */
3039 function wfSplitWikiID( $wiki ) {
3040         $bits = explode( '-', $wiki, 2 );
3041         if ( count( $bits ) < 2 ) {
3042                 $bits[] = '';
3043         }
3044         return $bits;
3045 }
3046
3047 /**
3048  * Get a Database object.
3049  *
3050  * @param int $db Index of the connection to get. May be DB_MASTER for the
3051  *            master (for write queries), DB_REPLICA for potentially lagged read
3052  *            queries, or an integer >= 0 for a particular server.
3053  *
3054  * @param string|string[] $groups Query groups. An array of group names that this query
3055  *                belongs to. May contain a single string if the query is only
3056  *                in one group.
3057  *
3058  * @param string|bool $wiki The wiki ID, or false for the current wiki
3059  *
3060  * Note: multiple calls to wfGetDB(DB_REPLICA) during the course of one request
3061  * will always return the same object, unless the underlying connection or load
3062  * balancer is manually destroyed.
3063  *
3064  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3065  * updater to ensure that a proper database is being updated.
3066  *
3067  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
3068  *       on an injected instance of LoadBalancer.
3069  *
3070  * @return Database
3071  */
3072 function wfGetDB( $db, $groups = [], $wiki = false ) {
3073         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3074 }
3075
3076 /**
3077  * Get a load balancer object.
3078  *
3079  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancer()
3080  *              or MediaWikiServices::getDBLoadBalancerFactory() instead.
3081  *
3082  * @param string|bool $wiki Wiki ID, or false for the current wiki
3083  * @return LoadBalancer
3084  */
3085 function wfGetLB( $wiki = false ) {
3086         if ( $wiki === false ) {
3087                 return \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancer();
3088         } else {
3089                 $factory = \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
3090                 return $factory->getMainLB( $wiki );
3091         }
3092 }
3093
3094 /**
3095  * Get the load balancer factory object
3096  *
3097  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancerFactory() instead.
3098  *
3099  * @return LBFactory
3100  */
3101 function wfGetLBFactory() {
3102         return \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
3103 }
3104
3105 /**
3106  * Find a file.
3107  * Shortcut for RepoGroup::singleton()->findFile()
3108  *
3109  * @param string $title String or Title object
3110  * @param array $options Associative array of options (see RepoGroup::findFile)
3111  * @return File|bool File, or false if the file does not exist
3112  */
3113 function wfFindFile( $title, $options = [] ) {
3114         return RepoGroup::singleton()->findFile( $title, $options );
3115 }
3116
3117 /**
3118  * Get an object referring to a locally registered file.
3119  * Returns a valid placeholder object if the file does not exist.
3120  *
3121  * @param Title|string $title
3122  * @return LocalFile|null A File, or null if passed an invalid Title
3123  */
3124 function wfLocalFile( $title ) {
3125         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3126 }
3127
3128 /**
3129  * Should low-performance queries be disabled?
3130  *
3131  * @return bool
3132  * @codeCoverageIgnore
3133  */
3134 function wfQueriesMustScale() {
3135         global $wgMiserMode;
3136         return $wgMiserMode
3137                 || ( SiteStats::pages() > 100000
3138                 && SiteStats::edits() > 1000000
3139                 && SiteStats::users() > 10000 );
3140 }
3141
3142 /**
3143  * Get the path to a specified script file, respecting file
3144  * extensions; this is a wrapper around $wgScriptPath etc.
3145  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3146  *
3147  * @param string $script Script filename, sans extension
3148  * @return string
3149  */
3150 function wfScript( $script = 'index' ) {
3151         global $wgScriptPath, $wgScript, $wgLoadScript;
3152         if ( $script === 'index' ) {
3153                 return $wgScript;
3154         } elseif ( $script === 'load' ) {
3155                 return $wgLoadScript;
3156         } else {
3157                 return "{$wgScriptPath}/{$script}.php";
3158         }
3159 }
3160
3161 /**
3162  * Get the script URL.
3163  *
3164  * @return string Script URL
3165  */
3166 function wfGetScriptUrl() {
3167         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3168                 /* as it was called, minus the query string.
3169                  *
3170                  * Some sites use Apache rewrite rules to handle subdomains,
3171                  * and have PHP set up in a weird way that causes PHP_SELF
3172                  * to contain the rewritten URL instead of the one that the
3173                  * outside world sees.
3174                  *
3175                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
3176                  * provides containing the "before" URL.
3177                  */
3178                 return $_SERVER['SCRIPT_NAME'];
3179         } else {
3180                 return $_SERVER['URL'];
3181         }
3182 }
3183
3184 /**
3185  * Convenience function converts boolean values into "true"
3186  * or "false" (string) values
3187  *
3188  * @param bool $value
3189  * @return string
3190  */
3191 function wfBoolToStr( $value ) {
3192         return $value ? 'true' : 'false';
3193 }
3194
3195 /**
3196  * Get a platform-independent path to the null file, e.g. /dev/null
3197  *
3198  * @return string
3199  */
3200 function wfGetNull() {
3201         return wfIsWindows() ? 'NUL' : '/dev/null';
3202 }
3203
3204 /**
3205  * Waits for the replica DBs to catch up to the master position
3206  *
3207  * Use this when updating very large numbers of rows, as in maintenance scripts,
3208  * to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.
3209  *
3210  * By default this waits on the main DB cluster of the current wiki.
3211  * If $cluster is set to "*" it will wait on all DB clusters, including
3212  * external ones. If the lag being waiting on is caused by the code that
3213  * does this check, it makes since to use $ifWritesSince, particularly if
3214  * cluster is "*", to avoid excess overhead.
3215  *
3216  * Never call this function after a big DB write that is still in a transaction.
3217  * This only makes sense after the possible lag inducing changes were committed.
3218  *
3219  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3220  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3221  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3222  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3223  * @return bool Success (able to connect and no timeouts reached)
3224  * @deprecated since 1.27 Use LBFactory::waitForReplication
3225  */
3226 function wfWaitForSlaves(
3227         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3228 ) {
3229         if ( $timeout === null ) {
3230                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3231         }
3232
3233         if ( $cluster === '*' ) {
3234                 $cluster = false;
3235                 $wiki = false;
3236         } elseif ( $wiki === false ) {
3237                 $wiki = wfWikiID();
3238         }
3239
3240         try {
3241                 wfGetLBFactory()->waitForReplication( [
3242                         'wiki' => $wiki,
3243                         'cluster' => $cluster,
3244                         'timeout' => $timeout,
3245                         // B/C: first argument used to be "max seconds of lag"; ignore such values
3246                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
3247                 ] );
3248         } catch ( DBReplicationWaitError $e ) {
3249                 return false;
3250         }
3251
3252         return true;
3253 }
3254
3255 /**
3256  * Count down from $seconds to zero on the terminal, with a one-second pause
3257  * between showing each number. For use in command-line scripts.
3258  *
3259  * @codeCoverageIgnore
3260  * @param int $seconds
3261  */
3262 function wfCountDown( $seconds ) {
3263         for ( $i = $seconds; $i >= 0; $i-- ) {
3264                 if ( $i != $seconds ) {
3265                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3266                 }
3267                 echo $i;
3268                 flush();
3269                 if ( $i ) {
3270                         sleep( 1 );
3271                 }
3272         }
3273         echo "\n";
3274 }
3275
3276 /**
3277  * Replace all invalid characters with '-'.
3278  * Additional characters can be defined in $wgIllegalFileChars (see T22489).
3279  * By default, $wgIllegalFileChars includes ':', '/', '\'.
3280  *
3281  * @param string $name Filename to process
3282  * @return string
3283  */
3284 function wfStripIllegalFilenameChars( $name ) {
3285         global $wgIllegalFileChars;
3286         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3287         $name = preg_replace(
3288                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3289                 '-',
3290                 $name
3291         );
3292         // $wgIllegalFileChars may not include '/' and '\', so we still need to do this
3293         $name = wfBaseName( $name );
3294         return $name;
3295 }
3296
3297 /**
3298  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3299  *
3300  * @return int Resulting value of the memory limit.
3301  */
3302 function wfMemoryLimit() {
3303         global $wgMemoryLimit;
3304         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3305         if ( $memlimit != -1 ) {
3306                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3307                 if ( $conflimit == -1 ) {
3308                         wfDebug( "Removing PHP's memory limit\n" );
3309                         MediaWiki\suppressWarnings();
3310                         ini_set( 'memory_limit', $conflimit );
3311                         MediaWiki\restoreWarnings();
3312                         return $conflimit;
3313                 } elseif ( $conflimit > $memlimit ) {
3314                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3315                         MediaWiki\suppressWarnings();
3316                         ini_set( 'memory_limit', $conflimit );
3317                         MediaWiki\restoreWarnings();
3318                         return $conflimit;
3319                 }
3320         }
3321         return $memlimit;
3322 }
3323
3324 /**
3325  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3326  *
3327  * @return int Prior time limit
3328  * @since 1.26
3329  */
3330 function wfTransactionalTimeLimit() {
3331         global $wgTransactionalTimeLimit;
3332
3333         $timeLimit = ini_get( 'max_execution_time' );
3334         // Note that CLI scripts use 0
3335         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3336                 set_time_limit( $wgTransactionalTimeLimit );
3337         }
3338
3339         ignore_user_abort( true ); // ignore client disconnects
3340
3341         return $timeLimit;
3342 }
3343
3344 /**
3345  * Converts shorthand byte notation to integer form
3346  *
3347  * @param string $string
3348  * @param int $default Returned if $string is empty
3349  * @return int
3350  */
3351 function wfShorthandToInteger( $string = '', $default = -1 ) {
3352         $string = trim( $string );
3353         if ( $string === '' ) {
3354                 return $default;
3355         }
3356         $last = $string[strlen( $string ) - 1];
3357         $val = intval( $string );
3358         switch ( $last ) {
3359                 case 'g':
3360                 case 'G':
3361                         $val *= 1024;
3362                         // break intentionally missing
3363                 case 'm':
3364                 case 'M':
3365                         $val *= 1024;
3366                         // break intentionally missing
3367                 case 'k':
3368                 case 'K':
3369                         $val *= 1024;
3370         }
3371
3372         return $val;
3373 }
3374
3375 /**
3376  * Get the normalised IETF language tag
3377  * See unit test for examples.
3378  *
3379  * @param string $code The language code.
3380  * @return string The language code which complying with BCP 47 standards.
3381  */
3382 function wfBCP47( $code ) {
3383         $codeSegment = explode( '-', $code );
3384         $codeBCP = [];
3385         foreach ( $codeSegment as $segNo => $seg ) {
3386                 // when previous segment is x, it is a private segment and should be lc
3387                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3388                         $codeBCP[$segNo] = strtolower( $seg );
3389                 // ISO 3166 country code
3390                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3391                         $codeBCP[$segNo] = strtoupper( $seg );
3392                 // ISO 15924 script code
3393                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3394                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3395                 // Use lowercase for other cases
3396                 } else {
3397                         $codeBCP[$segNo] = strtolower( $seg );
3398                 }
3399         }
3400         $langCode = implode( '-', $codeBCP );
3401         return $langCode;
3402 }
3403
3404 /**
3405  * Get a specific cache object.
3406  *
3407  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3408  * @return BagOStuff
3409  */
3410 function wfGetCache( $cacheType ) {
3411         return ObjectCache::getInstance( $cacheType );
3412 }
3413
3414 /**
3415  * Get the main cache object
3416  *
3417  * @return BagOStuff
3418  */
3419 function wfGetMainCache() {
3420         global $wgMainCacheType;
3421         return ObjectCache::getInstance( $wgMainCacheType );
3422 }
3423
3424 /**
3425  * Get the cache object used by the message cache
3426  *
3427  * @return BagOStuff
3428  */
3429 function wfGetMessageCacheStorage() {
3430         global $wgMessageCacheType;
3431         return ObjectCache::getInstance( $wgMessageCacheType );
3432 }
3433
3434 /**
3435  * Get the cache object used by the parser cache
3436  *
3437  * @return BagOStuff
3438  */
3439 function wfGetParserCacheStorage() {
3440         global $wgParserCacheType;
3441         return ObjectCache::getInstance( $wgParserCacheType );
3442 }
3443
3444 /**
3445  * Call hook functions defined in $wgHooks
3446  *
3447  * @param string $event Event name
3448  * @param array $args Parameters passed to hook functions
3449  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3450  *
3451  * @return bool True if no handler aborted the hook
3452  * @deprecated since 1.25 - use Hooks::run
3453  */
3454 function wfRunHooks( $event, array $args = [], $deprecatedVersion = null ) {
3455         return Hooks::run( $event, $args, $deprecatedVersion );
3456 }
3457
3458 /**
3459  * Wrapper around php's unpack.
3460  *
3461  * @param string $format The format string (See php's docs)
3462  * @param string $data A binary string of binary data
3463  * @param int|bool $length The minimum length of $data or false. This is to
3464  *      prevent reading beyond the end of $data. false to disable the check.
3465  *
3466  * Also be careful when using this function to read unsigned 32 bit integer
3467  * because php might make it negative.
3468  *
3469  * @throws MWException If $data not long enough, or if unpack fails
3470  * @return array Associative array of the extracted data
3471  */
3472 function wfUnpack( $format, $data, $length = false ) {
3473         if ( $length !== false ) {
3474                 $realLen = strlen( $data );
3475                 if ( $realLen < $length ) {
3476                         throw new MWException( "Tried to use wfUnpack on a "
3477                                 . "string of length $realLen, but needed one "
3478                                 . "of at least length $length."
3479                         );
3480                 }
3481         }
3482
3483         MediaWiki\suppressWarnings();
3484         $result = unpack( $format, $data );
3485         MediaWiki\restoreWarnings();
3486
3487         if ( $result === false ) {
3488                 // If it cannot extract the packed data.
3489                 throw new MWException( "unpack could not unpack binary data" );
3490         }
3491         return $result;
3492 }
3493
3494 /**
3495  * Determine if an image exists on the 'bad image list'.
3496  *
3497  * The format of MediaWiki:Bad_image_list is as follows:
3498  *    * Only list items (lines starting with "*") are considered
3499  *    * The first link on a line must be a link to a bad image
3500  *    * Any subsequent links on the same line are considered to be exceptions,
3501  *      i.e. articles where the image may occur inline.
3502  *
3503  * @param string $name The image name to check
3504  * @param Title|bool $contextTitle The page on which the image occurs, if known
3505  * @param string $blacklist Wikitext of a file blacklist
3506  * @return bool
3507  */
3508 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3509         # Handle redirects; callers almost always hit wfFindFile() anyway,
3510         # so just use that method because it has a fast process cache.
3511         $file = wfFindFile( $name ); // get the final name
3512         $name = $file ? $file->getTitle()->getDBkey() : $name;
3513
3514         # Run the extension hook
3515         $bad = false;
3516         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3517                 return $bad;
3518         }
3519
3520         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3521         $key = wfMemcKey( 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist ) );
3522         $badImages = $cache->get( $key );
3523
3524         if ( $badImages === false ) { // cache miss
3525                 if ( $blacklist === null ) {
3526                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3527                 }
3528                 # Build the list now
3529                 $badImages = [];
3530                 $lines = explode( "\n", $blacklist );
3531                 foreach ( $lines as $line ) {
3532                         # List items only
3533                         if ( substr( $line, 0, 1 ) !== '*' ) {
3534                                 continue;
3535                         }
3536
3537                         # Find all links
3538                         $m = [];
3539                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3540                                 continue;
3541                         }
3542
3543                         $exceptions = [];
3544                         $imageDBkey = false;
3545                         foreach ( $m[1] as $i => $titleText ) {
3546                                 $title = Title::newFromText( $titleText );
3547                                 if ( !is_null( $title ) ) {
3548                                         if ( $i == 0 ) {
3549                                                 $imageDBkey = $title->getDBkey();
3550                                         } else {
3551                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3552                                         }
3553                                 }
3554                         }
3555
3556                         if ( $imageDBkey !== false ) {
3557                                 $badImages[$imageDBkey] = $exceptions;
3558                         }
3559                 }
3560                 $cache->set( $key, $badImages, 60 );
3561         }
3562
3563         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3564         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3565
3566         return $bad;
3567 }
3568
3569 /**
3570  * Determine whether the client at a given source IP is likely to be able to
3571  * access the wiki via HTTPS.
3572  *
3573  * @param string $ip The IPv4/6 address in the normal human-readable form
3574  * @return bool
3575  */
3576 function wfCanIPUseHTTPS( $ip ) {
3577         $canDo = true;
3578         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3579         return !!$canDo;
3580 }
3581
3582 /**
3583  * Determine input string is represents as infinity
3584  *
3585  * @param string $str The string to determine
3586  * @return bool
3587  * @since 1.25
3588  */
3589 function wfIsInfinity( $str ) {
3590         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3591         return in_array( $str, $infinityValues );
3592 }
3593
3594 /**
3595  * Returns true if these thumbnail parameters match one that MediaWiki
3596  * requests from file description pages and/or parser output.
3597  *
3598  * $params is considered non-standard if they involve a non-standard
3599  * width or any non-default parameters aside from width and page number.
3600  * The number of possible files with standard parameters is far less than
3601  * that of all combinations; rate-limiting for them can thus be more generious.
3602  *
3603  * @param File $file
3604  * @param array $params
3605  * @return bool
3606  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3607  */
3608 function wfThumbIsStandard( File $file, array $params ) {
3609         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3610
3611         $multipliers = [ 1 ];
3612         if ( $wgResponsiveImages ) {
3613                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3614                 // @see Linker::processResponsiveImages
3615                 $multipliers[] = 1.5;
3616                 $multipliers[] = 2;
3617         }
3618
3619         $handler = $file->getHandler();
3620         if ( !$handler || !isset( $params['width'] ) ) {
3621                 return false;
3622         }
3623
3624         $basicParams = [];
3625         if ( isset( $params['page'] ) ) {
3626                 $basicParams['page'] = $params['page'];
3627         }
3628
3629         $thumbLimits = [];
3630         $imageLimits = [];
3631         // Expand limits to account for multipliers
3632         foreach ( $multipliers as $multiplier ) {
3633                 $thumbLimits = array_merge( $thumbLimits, array_map(
3634                         function ( $width ) use ( $multiplier ) {
3635                                 return round( $width * $multiplier );
3636                         }, $wgThumbLimits )
3637                 );
3638                 $imageLimits = array_merge( $imageLimits, array_map(
3639                         function ( $pair ) use ( $multiplier ) {
3640                                 return [
3641                                         round( $pair[0] * $multiplier ),
3642                                         round( $pair[1] * $multiplier ),
3643                                 ];
3644                         }, $wgImageLimits )
3645                 );
3646         }
3647
3648         // Check if the width matches one of $wgThumbLimits
3649         if ( in_array( $params['width'], $thumbLimits ) ) {
3650                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3651                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3652                 $handler->normaliseParams( $file, $normalParams );
3653         } else {
3654                 // If not, then check if the width matchs one of $wgImageLimits
3655                 $match = false;
3656                 foreach ( $imageLimits as $pair ) {
3657                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3658                         // Decide whether the thumbnail should be scaled on width or height.
3659                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3660                         $handler->normaliseParams( $file, $normalParams );
3661                         // Check if this standard thumbnail size maps to the given width
3662                         if ( $normalParams['width'] == $params['width'] ) {
3663                                 $match = true;
3664                                 break;
3665                         }
3666                 }
3667                 if ( !$match ) {
3668                         return false; // not standard for description pages
3669                 }
3670         }
3671
3672         // Check that the given values for non-page, non-width, params are just defaults
3673         foreach ( $params as $key => $value ) {
3674                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3675                         return false;
3676                 }
3677         }
3678
3679         return true;
3680 }
3681
3682 /**
3683  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3684  *
3685  * Values that exist in both values will be combined with += (all values of the array
3686  * of $newValues will be added to the values of the array of $baseArray, while values,
3687  * that exists in both, the value of $baseArray will be used).
3688  *
3689  * @param array $baseArray The array where you want to add the values of $newValues to
3690  * @param array $newValues An array with new values
3691  * @return array The combined array
3692  * @since 1.26
3693  */
3694 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3695         // First merge items that are in both arrays
3696         foreach ( $baseArray as $name => &$groupVal ) {
3697                 if ( isset( $newValues[$name] ) ) {
3698                         $groupVal += $newValues[$name];
3699                 }
3700         }
3701         // Now add items that didn't exist yet
3702         $baseArray += $newValues;
3703
3704         return $baseArray;
3705 }