includes/collation/IcuCollation.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 /**
  22  * @since 1.16.3
  23  */
  24 class IcuCollation extends Collation {
  25         const FIRST_LETTER_VERSION = 2;
  26
  27         /** @var Collator */
  28         private $primaryCollator;
  29
  30         /** @var Collator */
  31         private $mainCollator;
  32
  33         /** @var string */
  34         private $locale;
  35
  36         /** @var Language */
  37         protected $digitTransformLanguage;
  38
  39         /** @var array */
  40         private $firstLetterData;
  41
  42         /**
  43          * Unified CJK blocks.
  44          *
  45          * The same definition of a CJK block must be used for both Collation and
  46          * generateCollationData.php. These blocks are omitted from the first
  47          * letter data, as an optimisation measure and because the default UCA table
  48          * is pretty useless for sorting Chinese text anyway. Japanese and Korean
  49          * blocks are not included here, because they are smaller and more useful.
  50          */
  51         private static $cjkBlocks = [
  52                 [ 0x2E80, 0x2EFF ], // CJK Radicals Supplement
  53                 [ 0x2F00, 0x2FDF ], // Kangxi Radicals
  54                 [ 0x2FF0, 0x2FFF ], // Ideographic Description Characters
  55                 [ 0x3000, 0x303F ], // CJK Symbols and Punctuation
  56                 [ 0x31C0, 0x31EF ], // CJK Strokes
  57                 [ 0x3200, 0x32FF ], // Enclosed CJK Letters and Months
  58                 [ 0x3300, 0x33FF ], // CJK Compatibility
  59                 [ 0x3400, 0x4DBF ], // CJK Unified Ideographs Extension A
  60                 [ 0x4E00, 0x9FFF ], // CJK Unified Ideographs
  61                 [ 0xF900, 0xFAFF ], // CJK Compatibility Ideographs
  62                 [ 0xFE30, 0xFE4F ], // CJK Compatibility Forms
  63                 [ 0x20000, 0x2A6DF ], // CJK Unified Ideographs Extension B
  64                 [ 0x2A700, 0x2B73F ], // CJK Unified Ideographs Extension C
  65                 [ 0x2B740, 0x2B81F ], // CJK Unified Ideographs Extension D
  66                 [ 0x2F800, 0x2FA1F ], // CJK Compatibility Ideographs Supplement
  67         ];
  68
  69         /**
  70          * Additional characters (or character groups) to be considered separate
  71          * letters for given languages, or to be removed from the list of such
  72          * letters (denoted by keys starting with '-').
  73          *
  74          * These are additions to (or subtractions from) the data stored in the
  75          * first-letters-root.ser file (which among others includes full basic latin,
  76          * cyrillic and greek alphabets).
  77          *
  78          * "Separate letter" is a letter that would have a separate heading/section
  79          * for it in a dictionary or a phone book in this language. This data isn't
  80          * used for sorting (the ICU library handles that), only for deciding which
  81          * characters (or character groups) to use as headings.
  82          *
  83          * Initially generated based on the primary level of Unicode collation
  84          * tailorings available at http://developer.mimer.com/charts/tailorings.htm ,
  85          * later modified.
  86          *
  87          * Empty arrays are intended; this signifies that the data for the language is
  88          * available and that there are, in fact, no additional letters to consider.
  89          */
  90         private static $tailoringFirstLetters = [
  91                 // Verified by native speakers
  92                 'be' => [ "Ё" ],
  93                 'be-tarask' => [ "Ё" ],
  94                 'cy' => [ "Ch", "Dd", "Ff", "Ng", "Ll", "Ph", "Rh", "Th" ],
  95                 'en' => [],
  96                 'fa' => [ "آ", "ء", "ه" ],
  97                 'fi' => [ "Å", "Ä", "Ö" ],
  98                 'fr' => [],
  99                 'hu' => [ "Cs", "Dz", "Dzs", "Gy", "Ly", "Ny", "Ö", "Sz", "Ty", "Ü", "Zs" ],
 100                 'is' => [ "Á", "Ð", "É", "Í", "Ó", "Ú", "Ý", "Þ", "Æ", "Ö", "Å" ],
 101                 'it' => [],
 102                 'lv' => [ "Č", "Ģ", "Ķ", "Ļ", "Ņ", "Š", "Ž" ],
 103                 'pl' => [ "Ą", "Ć", "Ę", "Ł", "Ń", "Ó", "Ś", "Ź", "Ż" ],
 104                 'pt' => [],
 105                 'ru' => [],
 106                 'sv' => [ "Å", "Ä", "Ö" ],
 107                 'sv@collation=standard' => [ "Å", "Ä", "Ö" ],
 108                 'uk' => [ "Ґ", "Ь" ],
 109                 'vi' => [ "Ă", "Â", "Đ", "Ê", "Ô", "Ơ", "Ư" ],
 110                 // Not verified, but likely correct
 111                 'af' => [],
 112                 'ast' => [ "Ch", "Ll", "Ñ" ],
 113                 'az' => [ "Ç", "Ə", "Ğ", "İ", "Ö", "Ş", "Ü" ],
 114                 'bg' => [],
 115                 'br' => [ "Ch", "C'h" ],
 116                 'bs' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
 117                 'ca' => [],
 118                 'co' => [],
 119                 'cs' => [ "Č", "Ch", "Ř", "Š", "Ž" ],
 120                 'da' => [ "Æ", "Ø", "Å" ],
 121                 'de' => [],
 122                 'dsb' => [ "Č", "Ć", "Dź", "Ě", "Ch", "Ł", "Ń", "Ŕ", "Š", "Ś", "Ž", "Ź" ],
 123                 'el' => [],
 124                 'eo' => [ "Ĉ", "Ĝ", "Ĥ", "Ĵ", "Ŝ", "Ŭ" ],
 125                 'es' => [ "Ñ" ],
 126                 'et' => [ "Š", "Ž", "Õ", "Ä", "Ö", "Ü", "W" ], // added W for CollationEt (xx-uca-et)
 127                 'eu' => [ "Ñ" ],
 128                 'fo' => [ "Á", "Ð", "Í", "Ó", "Ú", "Ý", "Æ", "Ø", "Å" ],
 129                 'fur' => [ "À", "Á", "Â", "È", "Ì", "Ò", "Ù" ],
 130                 'fy' => [],
 131                 'ga' => [],
 132                 'gd' => [],
 133                 'gl' => [ "Ch", "Ll", "Ñ" ],
 134                 'hr' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
 135                 'hsb' => [ "Č", "Dź", "Ě", "Ch", "Ł", "Ń", "Ř", "Š", "Ć", "Ž" ],
 136                 'kk' => [ "Ү", "І" ],
 137                 'kl' => [ "Æ", "Ø", "Å" ],
 138                 'ku' => [ "Ç", "Ê", "Î", "Ş", "Û" ],
 139                 'ky' => [ "Ё" ],
 140                 'la' => [],
 141                 'lb' => [],
 142                 'lt' => [ "Č", "Š", "Ž" ],
 143                 'mk' => [],
 144                 'mo' => [ "Ă", "Â", "Î", "Ş", "Ţ" ],
 145                 'mt' => [ "Ċ", "Ġ", "Għ", "Ħ", "Ż" ],
 146                 'nl' => [],
 147                 'no' => [ "Æ", "Ø", "Å" ],
 148                 'oc' => [],
 149                 'rm' => [],
 150                 'ro' => [ "Ă", "Â", "Î", "Ş", "Ţ" ],
 151                 'rup' => [ "Ă", "Â", "Î", "Ľ", "Ń", "Ş", "Ţ" ],
 152                 'sco' => [],
 153                 'sk' => [ "Ä", "Č", "Ch", "Ô", "Š", "Ž" ],
 154                 'sl' => [ "Č", "Š", "Ž" ],
 155                 'smn' => [ "Á", "Č", "Đ", "Ŋ", "Š", "Ŧ", "Ž", "Æ", "Ø", "Å", "Ä", "Ö" ],
 156                 'sq' => [ "Ç", "Dh", "Ë", "Gj", "Ll", "Nj", "Rr", "Sh", "Th", "Xh", "Zh" ],
 157                 'sr' => [],
 158                 'ta' => [
 159                         "\xE0\xAE\x82", "ஃ", "க்ஷ", "க்", "ங்", "ச்", "ஞ்", "ட்", "ண்", "த்", "ந்",
 160                         "ப்", "ம்", "ய்", "ர்", "ல்", "வ்", "ழ்", "ள்", "ற்", "ன்", "ஜ்", "ஶ்", "ஷ்",
 161                         "ஸ்", "ஹ்", "க்ஷ்"
 162                 ],
 163                 'tk' => [ "Ç", "Ä", "Ž", "Ň", "Ö", "Ş", "Ü", "Ý" ],
 164                 'tl' => [ "Ñ", "Ng" ],
 165                 'tr' => [ "Ç", "Ğ", "İ", "Ö", "Ş", "Ü" ],
 166                 'tt' => [ "Ә", "Ө", "Ү", "Җ", "Ң", "Һ" ],
 167                 'uz' => [ "Ch", "G'", "Ng", "O'", "Sh" ],
 168         ];
 169
 170         /**
 171          * @since 1.16.3
 172          */
 173         const RECORD_LENGTH = 14;
 174
 175         public function __construct( $locale ) {
 176                 if ( !extension_loaded( 'intl' ) ) {
 177                         throw new MWException( 'An ICU collation was requested, ' .
 178                                 'but the intl extension is not available.' );
 179                 }
 180
 181                 $this->locale = $locale;
 182                 // Drop everything after the '@' in locale's name
 183                 $localeParts = explode( '@', $locale );
 184                 $this->digitTransformLanguage = Language::factory( $locale === 'root' ? 'en' : $localeParts[0] );
 185
 186                 $this->mainCollator = Collator::create( $locale );
 187                 if ( !$this->mainCollator ) {
 188                         throw new MWException( "Invalid ICU locale specified for collation: $locale" );
 189                 }
 190
 191                 $this->primaryCollator = Collator::create( $locale );
 192                 $this->primaryCollator->setStrength( Collator::PRIMARY );
 193         }
 194
 195         public function getSortKey( $string ) {
 196                 return $this->mainCollator->getSortKey( $string );
 197         }
 198
 199         public function getPrimarySortKey( $string ) {
 200                 return $this->primaryCollator->getSortKey( $string );
 201         }
 202
 203         public function getFirstLetter( $string ) {
 204                 $string = strval( $string );
 205                 if ( $string === '' ) {
 206                         return '';
 207                 }
 208
 209                 // Check for CJK
 210                 $firstChar = mb_substr( $string, 0, 1, 'UTF-8' );
 211                 if ( ord( $firstChar ) > 0x7f && self::isCjk( UtfNormal\Utils::utf8ToCodepoint( $firstChar ) ) ) {
 212                         return $firstChar;
 213                 }
 214
 215                 $sortKey = $this->getPrimarySortKey( $string );
 216
 217                 // Do a binary search to find the correct letter to sort under
 218                 $min = ArrayUtils::findLowerBound(
 219                         [ $this, 'getSortKeyByLetterIndex' ],
 220                         $this->getFirstLetterCount(),
 221                         'strcmp',
 222                         $sortKey );
 223
 224                 if ( $min === false ) {
 225                         // Before the first letter
 226                         return '';
 227                 }
 228                 return $this->getLetterByIndex( $min );
 229         }
 230
 231         /**
 232          * @since 1.16.3
 233          * @return array
 234          */
 235         public function getFirstLetterData() {
 236                 if ( $this->firstLetterData === null ) {
 237                         $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 238                         $cacheKey = $cache->makeKey(
 239                                 'first-letters',
 240                                 $this->locale,
 241                                 $this->digitTransformLanguage->getCode(),
 242                                 self::getICUVersion(),
 243                                 self::FIRST_LETTER_VERSION
 244                         );
 245                         $this->firstLetterData = $cache->getWithSetCallback( $cacheKey, $cache::TTL_WEEK, function () {
 246                                 return $this->fetchFirstLetterData();
 247                         } );
 248                 }
 249                 return $this->firstLetterData;
 250         }
 251
 252         /**
 253          * @return array
 254          * @throws MWException
 255          */
 256         private function fetchFirstLetterData() {
 257                 // Generate data from serialized data file
 258                 if ( isset( self::$tailoringFirstLetters[$this->locale] ) ) {
 259                         $letters = wfGetPrecompiledData( 'first-letters-root.ser' );
 260                         // Append additional characters
 261                         $letters = array_merge( $letters, self::$tailoringFirstLetters[$this->locale] );
 262                         // Remove unnecessary ones, if any
 263                         if ( isset( self::$tailoringFirstLetters['-' . $this->locale] ) ) {
 264                                 $letters = array_diff( $letters, self::$tailoringFirstLetters['-' . $this->locale] );
 265                         }
 266                         // Apply digit transforms
 267                         $digits = [ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' ];
 268                         $letters = array_diff( $letters, $digits );
 269                         foreach ( $digits as $digit ) {
 270                                 $letters[] = $this->digitTransformLanguage->formatNum( $digit, true );
 271                         }
 272                 } else {
 273                         $letters = wfGetPrecompiledData( "first-letters-{$this->locale}.ser" );
 274                         if ( $letters === false ) {
 275                                 throw new MWException( "MediaWiki does not support ICU locale " .
 276                                         "\"{$this->locale}\"" );
 277                         }
 278                 }
 279
 280                 /* Sort the letters.
 281                  *
 282                  * It's impossible to have the precompiled data file properly sorted,
 283                  * because the sort order changes depending on ICU version. If the
 284                  * array is not properly sorted, the binary search will return random
 285                  * results.
 286                  *
 287                  * We also take this opportunity to remove primary collisions.
 288                  */
 289                 $letterMap = [];
 290                 foreach ( $letters as $letter ) {
 291                         $key = $this->getPrimarySortKey( $letter );
 292                         if ( isset( $letterMap[$key] ) ) {
 293                                 // Primary collision
 294                                 // Keep whichever one sorts first in the main collator
 295                                 if ( $this->mainCollator->compare( $letter, $letterMap[$key] ) < 0 ) {
 296                                         $letterMap[$key] = $letter;
 297                                 }
 298                         } else {
 299                                 $letterMap[$key] = $letter;
 300                         }
 301                 }
 302                 ksort( $letterMap, SORT_STRING );
 303
 304                 /* Remove duplicate prefixes. Basically if something has a sortkey
 305                  * which is a prefix of some other sortkey, then it is an
 306                  * expansion and probably should not be considered a section
 307                  * header.
 308                  *
 309                  * For example 'þ' is sometimes sorted as if it is the letters
 310                  * 'th'. Other times it is its own primary element. Another
 311                  * example is '₨'. Sometimes its a currency symbol. Sometimes it
 312                  * is an 'R' followed by an 's'.
 313                  *
 314                  * Additionally an expanded element should always sort directly
 315                  * after its first element due to they way sortkeys work.
 316                  *
 317                  * UCA sortkey elements are of variable length but no collation
 318                  * element should be a prefix of some other element, so I think
 319                  * this is safe. See:
 320                  * - https://ssl.icu-project.org/repos/icu/icuhtml/trunk/design/collation/ICU_collation_design.htm
 321                  * - http://site.icu-project.org/design/collation/uca-weight-allocation
 322                  *
 323                  * Additionally, there is something called primary compression to
 324                  * worry about. Basically, if you have two primary elements that
 325                  * are more than one byte and both start with the same byte then
 326                  * the first byte is dropped on the second primary. Additionally
 327                  * either \x03 or \xFF may be added to mean that the next primary
 328                  * does not start with the first byte of the first primary.
 329                  *
 330                  * This shouldn't matter much, as the first primary is not
 331                  * changed, and that is what we are comparing against.
 332                  *
 333                  * tl;dr: This makes some assumptions about how icu implements
 334                  * collations. It seems incredibly unlikely these assumptions
 335                  * will change, but nonetheless they are assumptions.
 336                  */
 337
 338                 $prev = false;
 339                 $duplicatePrefixes = [];
 340                 foreach ( $letterMap as $key => $value ) {
 341                         // Remove terminator byte. Otherwise the prefix
 342                         // comparison will get hung up on that.
 343                         $trimmedKey = rtrim( $key, "\0" );
 344                         if ( $prev === false || $prev === '' ) {
 345                                 $prev = $trimmedKey;
 346                                 // We don't yet have a collation element
 347                                 // to compare against, so continue.
 348                                 continue;
 349                         }
 350
 351                         // Due to the fact the array is sorted, we only have
 352                         // to compare with the element directly previous
 353                         // to the current element (skipping expansions).
 354                         // An element "X" will always sort directly
 355                         // before "XZ" (Unless we have "XY", but we
 356                         // do not update $prev in that case).
 357                         if ( substr( $trimmedKey, 0, strlen( $prev ) ) === $prev ) {
 358                                 $duplicatePrefixes[] = $key;
 359                                 // If this is an expansion, we don't want to
 360                                 // compare the next element to this element,
 361                                 // but to what is currently $prev
 362                                 continue;
 363                         }
 364                         $prev = $trimmedKey;
 365                 }
 366                 foreach ( $duplicatePrefixes as $badKey ) {
 367                         wfDebug( "Removing '{$letterMap[$badKey]}' from first letters.\n" );
 368                         unset( $letterMap[$badKey] );
 369                         // This code assumes that unsetting does not change sort order.
 370                 }
 371                 $data = [
 372                         'chars' => array_values( $letterMap ),
 373                         'keys' => array_keys( $letterMap ),
 374                 ];
 375
 376                 // Reduce memory usage before caching
 377                 unset( $letterMap );
 378
 379                 return $data;
 380         }
 381
 382         /**
 383          * @since 1.16.3
 384          */
 385         public function getLetterByIndex( $index ) {
 386                 return $this->getFirstLetterData()['chars'][$index];
 387         }
 388
 389         /**
 390          * @since 1.16.3
 391          */
 392         public function getSortKeyByLetterIndex( $index ) {
 393                 return $this->getFirstLetterData()['keys'][$index];
 394         }
 395
 396         /**
 397          * @since 1.16.3
 398          */
 399         public function getFirstLetterCount() {
 400                 return count( $this->getFirstLetterData()['chars'] );
 401         }
 402
 403         /**
 404          * @since 1.16.3
 405          */
 406         public static function isCjk( $codepoint ) {
 407                 foreach ( self::$cjkBlocks as $block ) {
 408                         if ( $codepoint >= $block[0] && $codepoint <= $block[1] ) {
 409                                 return true;
 410                         }
 411                 }
 412                 return false;
 413         }
 414
 415         /**
 416          * Return the version of ICU library used by PHP's intl extension,
 417          * or false when the extension is not installed of the version
 418          * can't be determined.
 419          *
 420          * The constant INTL_ICU_VERSION this function refers to isn't really
 421          * documented. It is available since PHP 5.3.7 (see PHP bug 54561).
 422          * This function will return false on older PHPs.
 423          *
 424          * @since 1.21
 425          * @return string|bool
 426          */
 427         static function getICUVersion() {
 428                 return defined( 'INTL_ICU_VERSION' ) ? INTL_ICU_VERSION : false;
 429         }
 430
 431         /**
 432          * Return the version of Unicode appropriate for the version of ICU library
 433          * currently in use, or false when it can't be determined.
 434          *
 435          * @since 1.21
 436          * @return string|bool
 437          */
 438         static function getUnicodeVersionForICU() {
 439                 $icuVersion = IcuCollation::getICUVersion();
 440                 if ( !$icuVersion ) {
 441                         return false;
 442                 }
 443
 444                 $versionPrefix = substr( $icuVersion, 0, 3 );
 445                 // Source: http://site.icu-project.org/download
 446                 $map = [
 447                         '50.' => '6.2',
 448                         '49.' => '6.1',
 449                         '4.8' => '6.0',
 450                         '4.6' => '6.0',
 451                         '4.4' => '5.2',
 452                         '4.2' => '5.1',
 453                         '4.0' => '5.1',
 454                         '3.8' => '5.0',
 455                         '3.6' => '5.0',
 456                         '3.4' => '4.1',
 457                 ];
 458
 459                 if ( isset( $map[$versionPrefix] ) ) {
 460                         return $map[$versionPrefix];
 461                 } else {
 462                         return false;
 463                 }
 464         }
 465 }