includes/Collation.php

   1 <?php
   2 /**
   3  * Database row sorting.
   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 abstract class Collation {
  24         static $instance;
  25
  26         /**
  27          * @return Collation
  28          */
  29         static function singleton() {
  30                 if ( !self::$instance ) {
  31                         global $wgCategoryCollation;
  32                         self::$instance = self::factory( $wgCategoryCollation );
  33                 }
  34                 return self::$instance;
  35         }
  36
  37         /**
  38          * @throws MWException
  39          * @param $collationName string
  40          * @return Collation
  41          */
  42         static function factory( $collationName ) {
  43                 switch( $collationName ) {
  44                         case 'uppercase':
  45                                 return new UppercaseCollation;
  46                         case 'identity':
  47                                 return new IdentityCollation;
  48                         case 'uca-default':
  49                                 return new IcuCollation( 'root' );
  50                         default:
  51                                 $match = array();
  52                                 if ( preg_match( '/^uca-([a-z-]+)$/', $collationName, $match ) ) {
  53                                         return new IcuCollation( $match[1] );
  54                                 }
  55
  56                                 # Provide a mechanism for extensions to hook in.
  57                                 $collationObject = null;
  58                                 wfRunHooks( 'Collation::factory', array( $collationName, &$collationObject ) );
  59
  60                                 if ( $collationObject instanceof Collation ) {
  61                                         return $collationObject;
  62                                 }
  63
  64                                 // If all else fails...
  65                                 throw new MWException( __METHOD__.": unknown collation type \"$collationName\"" );
  66                 }
  67         }
  68
  69         /**
  70          * Given a string, convert it to a (hopefully short) key that can be used
  71          * for efficient sorting.  A binary sort according to the sortkeys
  72          * corresponds to a logical sort of the corresponding strings.  Current
  73          * code expects that a line feed character should sort before all others, but
  74          * has no other particular expectations (and that one can be changed if
  75          * necessary).
  76          *
  77          * @param string $string UTF-8 string
  78          * @return string Binary sortkey
  79          */
  80         abstract function getSortKey( $string );
  81
  82         /**
  83          * Given a string, return the logical "first letter" to be used for
  84          * grouping on category pages and so on.  This has to be coordinated
  85          * carefully with convertToSortkey(), or else the sorted list might jump
  86          * back and forth between the same "initial letters" or other pathological
  87          * behavior.  For instance, if you just return the first character, but "a"
  88          * sorts the same as "A" based on getSortKey(), then you might get a
  89          * list like
  90          *
  91          * == A ==
  92          * * [[Aardvark]]
  93          *
  94          * == a ==
  95          * * [[antelope]]
  96          *
  97          * == A ==
  98          * * [[Ape]]
  99          *
 100          * etc., assuming for the sake of argument that $wgCapitalLinks is false.
 101          *
 102          * @param string $string UTF-8 string
 103          * @return string UTF-8 string corresponding to the first letter of input
 104          */
 105         abstract function getFirstLetter( $string );
 106 }
 107
 108 class UppercaseCollation extends Collation {
 109         var $lang;
 110         function __construct() {
 111                 // Get a language object so that we can use the generic UTF-8 uppercase
 112                 // function there
 113                 $this->lang = Language::factory( 'en' );
 114         }
 115
 116         function getSortKey( $string ) {
 117                 return $this->lang->uc( $string );
 118         }
 119
 120         function getFirstLetter( $string ) {
 121                 if ( $string[0] == "\0" ) {
 122                         $string = substr( $string, 1 );
 123                 }
 124                 return $this->lang->ucfirst( $this->lang->firstChar( $string ) );
 125         }
 126 }
 127
 128 /**
 129  * Collation class that's essentially a no-op.
 130  *
 131  * Does sorting based on binary value of the string.
 132  * Like how things were pre 1.17.
 133  */
 134 class IdentityCollation extends Collation {
 135
 136         function getSortKey( $string ) {
 137                 return $string;
 138         }
 139
 140         function getFirstLetter( $string ) {
 141                 global $wgContLang;
 142                 // Copied from UppercaseCollation.
 143                 // I'm kind of unclear on when this could happen...
 144                 if ( $string[0] == "\0" ) {
 145                         $string = substr( $string, 1 );
 146                 }
 147                 return $wgContLang->firstChar( $string );
 148         }
 149 }
 150
 151
 152 class IcuCollation extends Collation {
 153         var $primaryCollator, $mainCollator, $locale;
 154         var $firstLetterData;
 155
 156         /**
 157          * Unified CJK blocks.
 158          *
 159          * The same definition of a CJK block must be used for both Collation and
 160          * generateCollationData.php. These blocks are omitted from the first
 161          * letter data, as an optimisation measure and because the default UCA table
 162          * is pretty useless for sorting Chinese text anyway. Japanese and Korean
 163          * blocks are not included here, because they are smaller and more useful.
 164          */
 165         static $cjkBlocks = array(
 166                 array( 0x2E80, 0x2EFF ), // CJK Radicals Supplement
 167                 array( 0x2F00, 0x2FDF ), // Kangxi Radicals
 168                 array( 0x2FF0, 0x2FFF ), // Ideographic Description Characters
 169                 array( 0x3000, 0x303F ), // CJK Symbols and Punctuation
 170                 array( 0x31C0, 0x31EF ), // CJK Strokes
 171                 array( 0x3200, 0x32FF ), // Enclosed CJK Letters and Months
 172                 array( 0x3300, 0x33FF ), // CJK Compatibility
 173                 array( 0x3400, 0x4DBF ), // CJK Unified Ideographs Extension A
 174                 array( 0x4E00, 0x9FFF ), // CJK Unified Ideographs
 175                 array( 0xF900, 0xFAFF ), // CJK Compatibility Ideographs
 176                 array( 0xFE30, 0xFE4F ), // CJK Compatibility Forms
 177                 array( 0x20000, 0x2A6DF ), // CJK Unified Ideographs Extension B
 178                 array( 0x2A700, 0x2B73F ), // CJK Unified Ideographs Extension C
 179                 array( 0x2B740, 0x2B81F ), // CJK Unified Ideographs Extension D
 180                 array( 0x2F800, 0x2FA1F ), // CJK Compatibility Ideographs Supplement
 181         );
 182
 183         /**
 184          * Additional characters (or character groups) to be considered separate
 185          * letters for given languages, compared to the data stored in the
 186          * first-letters-root.ser file (which among others includes full basic latin,
 187          * cyrillic and greek alphabets).
 188          *
 189          * "Separate letter" is a letter that would have a separate heading/section
 190          * for it in a dictionary or a phone book in this language. This data isn't
 191          * used for sorting (the ICU library handles that), only for deciding which
 192          * characters (or character groups) to use as headings.
 193          *
 194          * Initially generated based on the primary level of Unicode collation
 195          * tailorings available at http://developer.mimer.com/charts/tailorings.htm ,
 196          * later modified.
 197          *
 198          * Empty arrays are intended; this signifies that the data for the language is
 199          * available and that there are, in fact, no additional letters to consider.
 200          */
 201         static $tailoringFirstLetters = array(
 202                 // Verified by native speakers
 203                 'be' => array( "Ё" ),
 204                 'be-tarask' => array( "Ё" ),
 205                 'fi' => array( "Å", "Ä", "Ö" ),
 206                 'pl' => array( "Ą", "Ć", "Ę", "Ł", "Ń", "Ó", "Ś", "Ź", "Ż" ),
 207                 'ru' => array(),
 208                 // Not verified, but likely correct
 209                 'af' => array(),
 210                 'ast' => array( "CH", "LL", "Ñ" ),
 211                 'az' => array( "Ç", "Ə", "Ğ", "İ", "Ö", "Ş", "Ü" ),
 212                 'bg' => array(),
 213                 'br' => array( "CH", "C'H" ),
 214                 'bs' => array( "Č", "Ć", "DŽ", "Đ", "LJ", "NJ", "Š", "Ž" ),
 215                 'ca' => array(),
 216                 'co' => array(),
 217                 'cs' => array( "Č", "CH", "Ř", "Š", "Ž" ),
 218                 'cy' => array( "CH", "DD", "FF", "NG", "LL", "PH", "RH", "TH" ),
 219                 'da' => array( "Æ", "Ø", "Å" ),
 220                 'de' => array(),
 221                 'dsb' => array( "Č", "Ć", "DŹ", "Ě", "CH", "Ł", "Ń", "Ŕ", "Š", "Ś", "Ž", "Ź" ),
 222                 'el' => array(),
 223                 'en' => array(),
 224                 'eo' => array( "Ĉ", "Ĝ", "Ĥ", "Ĵ", "Ŝ", "Ŭ" ),
 225                 'es' => array( "Ñ" ),
 226                 'et' => array( "Š", "Ž", "Õ", "Ä", "Ö", "Ü" ),
 227                 'eu' => array( "Ñ" ),
 228                 'fo' => array( "Á", "Ð", "Í", "Ó", "Ú", "Ý", "Æ", "Ø", "Å" ),
 229                 'fr' => array(),
 230                 'fur' => array( "À", "Á", "Â", "È", "Ì", "Ò", "Ù" ),
 231                 'fy' => array(),
 232                 'ga' => array(),
 233                 'gd' => array(),
 234                 'gl' => array( "CH", "LL", "Ñ" ),
 235                 'hr' => array( "Č", "Ć", "DŽ", "Đ", "LJ", "NJ", "Š", "Ž" ),
 236                 'hsb' => array( "Č", "DŹ", "Ě", "CH", "Ł", "Ń", "Ř", "Š", "Ć", "Ž" ),
 237                 'hu' => array( "CS", "DZ", "DZS", "GY", "LY", "NY", "Ö", "SZ", "TY", "Ü", "ZS" ),
 238                 'is' => array( "Á", "Ð", "É", "Í", "Ó", "Ú", "Ý", "Þ", "Æ", "Ö", "Å" ),
 239                 'it' => array(),
 240                 'kk' => array( "Ү", "І" ),
 241                 'kl' => array( "Æ", "Ø", "Å" ),
 242                 'ku' => array( "Ç", "Ê", "Î", "Ş", "Û" ),
 243                 'ky' => array( "Ё" ),
 244                 'la' => array(),
 245                 'lb' => array(),
 246                 'lt' => array( "Č", "Š", "Ž" ),
 247                 'lv' => array( "Č", "Ģ", "Ķ", "Ļ", "Ņ", "Š", "Ž" ),
 248                 'mk' => array(),
 249                 'mo' => array( "Ă", "Â", "Î", "Ş", "Ţ" ),
 250                 'mt' => array( "Ċ", "Ġ", "GĦ", "Ħ", "Ż" ),
 251                 'nl' => array(),
 252                 'no' => array( "Æ", "Ø", "Å" ),
 253                 'oc' => array(),
 254                 'pt' => array(),
 255                 'rm' => array(),
 256                 'ro' => array( "Ă", "Â", "Î", "Ş", "Ţ" ),
 257                 'rup' => array( "Ă", "Â", "Î", "Ľ", "Ń", "Ş", "Ţ" ),
 258                 'sco' => array(),
 259                 'sk' => array( "Ä", "Č", "CH", "Ô", "Š", "Ž" ),
 260                 'sl' => array( "Č", "Š", "Ž" ),
 261                 'smn' => array( "Á", "Č", "Đ", "Ŋ", "Š", "Ŧ", "Ž", "Æ", "Ø", "Å", "Ä", "Ö" ),
 262                 'sq' => array( "Ç", "DH", "Ë", "GJ", "LL", "NJ", "RR", "SH", "TH", "XH", "ZH" ),
 263                 'sr' => array(),
 264                 'sv' => array( "Å", "Ä", "Ö" ),
 265                 'tk' => array( "Ç", "Ä", "Ž", "Ň", "Ö", "Ş", "Ü", "Ý" ),
 266                 'tl' => array( "Ñ", "NG" ),
 267                 'tr' => array( "Ç", "Ğ", "İ", "Ö", "Ş", "Ü" ),
 268                 'tt' => array( "Ә", "Ө", "Ү", "Җ", "Ң", "Һ" ),
 269                 'uk' => array( "Ґ", "Ь" ),
 270                 'uz' => array( "CH", "G'", "NG", "O'", "SH" ),
 271                 'vi' => array( "Ă", "Â", "Đ", "Ê", "Ô", "Ơ", "Ư" ),
 272         );
 273
 274         const RECORD_LENGTH = 14;
 275
 276         function __construct( $locale ) {
 277                 if ( !extension_loaded( 'intl' ) ) {
 278                         throw new MWException( 'An ICU collation was requested, ' .
 279                                 'but the intl extension is not available.' );
 280                 }
 281                 $this->locale = $locale;
 282                 $this->mainCollator = Collator::create( $locale );
 283                 if ( !$this->mainCollator ) {
 284                         throw new MWException( "Invalid ICU locale specified for collation: $locale" );
 285                 }
 286
 287                 $this->primaryCollator = Collator::create( $locale );
 288                 $this->primaryCollator->setStrength( Collator::PRIMARY );
 289         }
 290
 291         function getSortKey( $string ) {
 292                 // intl extension produces non null-terminated
 293                 // strings. Appending '' fixes it so that it doesn't generate
 294                 // a warning on each access in debug php.
 295                 wfSuppressWarnings();
 296                 $key = $this->mainCollator->getSortKey( $string ) . '';
 297                 wfRestoreWarnings();
 298                 return $key;
 299         }
 300
 301         function getPrimarySortKey( $string ) {
 302                 wfSuppressWarnings();
 303                 $key = $this->primaryCollator->getSortKey( $string ) . '';
 304                 wfRestoreWarnings();
 305                 return $key;
 306         }
 307
 308         function getFirstLetter( $string ) {
 309                 $string = strval( $string );
 310                 if ( $string === '' ) {
 311                         return '';
 312                 }
 313
 314                 // Check for CJK
 315                 $firstChar = mb_substr( $string, 0, 1, 'UTF-8' );
 316                 if ( ord( $firstChar ) > 0x7f
 317                         && self::isCjk( utf8ToCodepoint( $firstChar ) ) )
 318                 {
 319                         return $firstChar;
 320                 }
 321
 322                 $sortKey = $this->getPrimarySortKey( $string );
 323
 324                 // Do a binary search to find the correct letter to sort under
 325                 $min = $this->findLowerBound(
 326                         array( $this, 'getSortKeyByLetterIndex' ),
 327                         $this->getFirstLetterCount(),
 328                         'strcmp',
 329                         $sortKey );
 330
 331                 if ( $min === false ) {
 332                         // Before the first letter
 333                         return '';
 334                 }
 335                 return $this->getLetterByIndex( $min );
 336         }
 337
 338         function getFirstLetterData() {
 339                 if ( $this->firstLetterData !== null ) {
 340                         return $this->firstLetterData;
 341                 }
 342
 343                 $cache = wfGetCache( CACHE_ANYTHING );
 344                 $cacheKey = wfMemcKey( 'first-letters', $this->locale );
 345                 $cacheEntry = $cache->get( $cacheKey );
 346
 347                 if ( $cacheEntry ) {
 348                         $this->firstLetterData = $cacheEntry;
 349                         return $this->firstLetterData;
 350                 }
 351
 352                 // Generate data from serialized data file
 353
 354                 if ( isset ( self::$tailoringFirstLetters[$this->locale] ) ) {
 355                         $letters = wfGetPrecompiledData( "first-letters-root.ser" );
 356                         $letters = array_merge( $letters, self::$tailoringFirstLetters[$this->locale] );
 357                 } else {
 358                         $letters = wfGetPrecompiledData( "first-letters-{$this->locale}.ser" );
 359                         if ( $letters === false ) {
 360                                 throw new MWException( "MediaWiki does not support ICU locale " .
 361                                         "\"{$this->locale}\"" );
 362                         }
 363                 }
 364
 365                 // Sort the letters.
 366                 //
 367                 // It's impossible to have the precompiled data file properly sorted,
 368                 // because the sort order changes depending on ICU version. If the
 369                 // array is not properly sorted, the binary search will return random
 370                 // results.
 371                 //
 372                 // We also take this opportunity to remove primary collisions.
 373                 $letterMap = array();
 374                 foreach ( $letters as $letter ) {
 375                         $key = $this->getPrimarySortKey( $letter );
 376                         if ( isset( $letterMap[$key] ) ) {
 377                                 // Primary collision
 378                                 // Keep whichever one sorts first in the main collator
 379                                 if ( $this->mainCollator->compare( $letter, $letterMap[$key] ) < 0 ) {
 380                                         $letterMap[$key] = $letter;
 381                                 }
 382                         } else {
 383                                 $letterMap[$key] = $letter;
 384                         }
 385                 }
 386                 ksort( $letterMap, SORT_STRING );
 387                 $data = array(
 388                         'chars' => array_values( $letterMap ),
 389                         'keys' => array_keys( $letterMap )
 390                 );
 391
 392                 // Reduce memory usage before caching
 393                 unset( $letterMap );
 394
 395                 // Save to cache
 396                 $this->firstLetterData = $data;
 397                 $cache->set( $cacheKey, $data, 86400 * 7 /* 1 week */ );
 398                 return $data;
 399         }
 400
 401         function getLetterByIndex( $index ) {
 402                 if ( $this->firstLetterData === null ) {
 403                         $this->getFirstLetterData();
 404                 }
 405                 return $this->firstLetterData['chars'][$index];
 406         }
 407
 408         function getSortKeyByLetterIndex( $index ) {
 409                 if ( $this->firstLetterData === null ) {
 410                         $this->getFirstLetterData();
 411                 }
 412                 return $this->firstLetterData['keys'][$index];
 413         }
 414
 415         function getFirstLetterCount() {
 416                 if ( $this->firstLetterData === null ) {
 417                         $this->getFirstLetterData();
 418                 }
 419                 return count( $this->firstLetterData['chars'] );
 420         }
 421
 422         /**
 423          * Do a binary search, and return the index of the largest item that sorts
 424          * less than or equal to the target value.
 425          *
 426          * @param $valueCallback array A function to call to get the value with
 427          *     a given array index.
 428          * @param $valueCount int The number of items accessible via $valueCallback,
 429          *     indexed from 0 to $valueCount - 1
 430          * @param $comparisonCallback array A callback to compare two values, returning
 431          *     -1, 0 or 1 in the style of strcmp().
 432          * @param $target string The target value to find.
 433          *
 434          * @return int|bool The item index of the lower bound, or false if the target value
 435          *     sorts before all items.
 436          */
 437         function findLowerBound( $valueCallback, $valueCount, $comparisonCallback, $target ) {
 438                 if ( $valueCount === 0 ) {
 439                         return false;
 440                 }
 441
 442                 $min = 0;
 443                 $max = $valueCount;
 444                 do {
 445                         $mid = $min + ( ( $max - $min ) >> 1 );
 446                         $item = call_user_func( $valueCallback, $mid );
 447                         $comparison = call_user_func( $comparisonCallback, $target, $item );
 448                         if ( $comparison > 0 ) {
 449                                 $min = $mid;
 450                         } elseif ( $comparison == 0 ) {
 451                                 $min = $mid;
 452                                 break;
 453                         } else {
 454                                 $max = $mid;
 455                         }
 456                 } while ( $min < $max - 1 );
 457
 458                 if ( $min == 0 ) {
 459                         $item = call_user_func( $valueCallback, $min );
 460                         $comparison = call_user_func( $comparisonCallback, $target, $item );
 461                         if ( $comparison < 0 ) {
 462                                 // Before the first item
 463                                 return false;
 464                         }
 465                 }
 466                 return $min;
 467         }
 468
 469         static function isCjk( $codepoint ) {
 470                 foreach ( self::$cjkBlocks as $block ) {
 471                         if ( $codepoint >= $block[0] && $codepoint <= $block[1] ) {
 472                                 return true;
 473                         }
 474                 }
 475                 return false;
 476         }
 477
 478         /**
 479          * Return the version of ICU library used by PHP's intl extension,
 480          * or false when the extension is not installed of the version
 481          * can't be determined.
 482          *
 483          * The constant INTL_ICU_VERSION this function refers to isn't really
 484          * documented. It is available since PHP 5.3.7 (see PHP bug 54561).
 485          * This function will return false on older PHPs.
 486          *
 487          * @since 1.21
 488          * @return string|false
 489          */
 490         static function getICUVersion() {
 491                 return defined( 'INTL_ICU_VERSION' ) ? INTL_ICU_VERSION : false;
 492         }
 493
 494         /**
 495          * Return the version of Unicode appropriate for the version of ICU library
 496          * currently in use, or false when it can't be determined.
 497          *
 498          * @since 1.21
 499          * @return string|false
 500          */
 501         static function getUnicodeVersionForICU() {
 502                 $icuVersion = IcuCollation::getICUVersion();
 503                 if ( !$icuVersion ) {
 504                         return false;
 505                 }
 506
 507                 $versionPrefix = substr( $icuVersion, 0, 3 );
 508                 // Source: http://site.icu-project.org/download
 509                 $map = array(
 510                         '50.' => '6.2',
 511                         '49.' => '6.1',
 512                         '4.8' => '6.0',
 513                         '4.6' => '6.0',
 514                         '4.4' => '5.2',
 515                         '4.2' => '5.1',
 516                         '4.0' => '5.1',
 517                         '3.8' => '5.0',
 518                         '3.6' => '5.0',
 519                         '3.4' => '4.1',
 520                 );
 521
 522                 if ( isset( $map[$versionPrefix] ) ) {
 523                         return $map[$versionPrefix];
 524                 } else {
 525                         return false;
 526                 }
 527         }
 528 }