wiki.techinc.nl/includes/Collation.php

351 lines
9.9 KiB
PHP

<?php
abstract class Collation {
static $instance;
/**
* @return Collation
*/
static function singleton() {
if ( !self::$instance ) {
global $wgCategoryCollation;
self::$instance = self::factory( $wgCategoryCollation );
}
return self::$instance;
}
/**
* @throws MWException
* @param $collationName string
* @return Collation
*/
static function factory( $collationName ) {
switch( $collationName ) {
case 'uppercase':
return new UppercaseCollation;
case 'identity':
return new IdentityCollation;
case 'uca-default':
return new IcuCollation( 'root' );
default:
# Provide a mechanism for extensions to hook in.
$collationObject = null;
wfRunHooks( 'Collation::factory', array( $collationName, &$collationObject ) );
if ( $collationObject instanceof Collation ) {
return $collationObject;
}
// If all else fails...
throw new MWException( __METHOD__.": unknown collation type \"$collationName\"" );
}
}
/**
* Given a string, convert it to a (hopefully short) key that can be used
* for efficient sorting. A binary sort according to the sortkeys
* corresponds to a logical sort of the corresponding strings. Current
* code expects that a line feed character should sort before all others, but
* has no other particular expectations (and that one can be changed if
* necessary).
*
* @param string $string UTF-8 string
* @return string Binary sortkey
*/
abstract function getSortKey( $string );
/**
* Given a string, return the logical "first letter" to be used for
* grouping on category pages and so on. This has to be coordinated
* carefully with convertToSortkey(), or else the sorted list might jump
* back and forth between the same "initial letters" or other pathological
* behavior. For instance, if you just return the first character, but "a"
* sorts the same as "A" based on getSortKey(), then you might get a
* list like
*
* == A ==
* * [[Aardvark]]
*
* == a ==
* * [[antelope]]
*
* == A ==
* * [[Ape]]
*
* etc., assuming for the sake of argument that $wgCapitalLinks is false.
*
* @param string $string UTF-8 string
* @return string UTF-8 string corresponding to the first letter of input
*/
abstract function getFirstLetter( $string );
}
class UppercaseCollation extends Collation {
var $lang;
function __construct() {
// Get a language object so that we can use the generic UTF-8 uppercase
// function there
$this->lang = Language::factory( 'en' );
}
function getSortKey( $string ) {
return $this->lang->uc( $string );
}
function getFirstLetter( $string ) {
if ( $string[0] == "\0" ) {
$string = substr( $string, 1 );
}
return $this->lang->ucfirst( $this->lang->firstChar( $string ) );
}
}
/**
* Collation class that's essentially a no-op.
*
* Does sorting based on binary value of the string.
* Like how things were pre 1.17.
*/
class IdentityCollation extends Collation {
function getSortKey( $string ) {
return $string;
}
function getFirstLetter( $string ) {
global $wgContLang;
// Copied from UppercaseCollation.
// I'm kind of unclear on when this could happen...
if ( $string[0] == "\0" ) {
$string = substr( $string, 1 );
}
return $wgContLang->firstChar( $string );
}
}
class IcuCollation extends Collation {
var $primaryCollator, $mainCollator, $locale;
var $firstLetterData;
/**
* Unified CJK blocks.
*
* The same definition of a CJK block must be used for both Collation and
* generateCollationData.php. These blocks are omitted from the first
* letter data, as an optimisation measure and because the default UCA table
* is pretty useless for sorting Chinese text anyway. Japanese and Korean
* blocks are not included here, because they are smaller and more useful.
*/
static $cjkBlocks = array(
array( 0x2E80, 0x2EFF ), // CJK Radicals Supplement
array( 0x2F00, 0x2FDF ), // Kangxi Radicals
array( 0x2FF0, 0x2FFF ), // Ideographic Description Characters
array( 0x3000, 0x303F ), // CJK Symbols and Punctuation
array( 0x31C0, 0x31EF ), // CJK Strokes
array( 0x3200, 0x32FF ), // Enclosed CJK Letters and Months
array( 0x3300, 0x33FF ), // CJK Compatibility
array( 0x3400, 0x4DBF ), // CJK Unified Ideographs Extension A
array( 0x4E00, 0x9FFF ), // CJK Unified Ideographs
array( 0xF900, 0xFAFF ), // CJK Compatibility Ideographs
array( 0xFE30, 0xFE4F ), // CJK Compatibility Forms
array( 0x20000, 0x2A6DF ), // CJK Unified Ideographs Extension B
array( 0x2A700, 0x2B73F ), // CJK Unified Ideographs Extension C
array( 0x2B740, 0x2B81F ), // CJK Unified Ideographs Extension D
array( 0x2F800, 0x2FA1F ), // CJK Compatibility Ideographs Supplement
);
const RECORD_LENGTH = 14;
function __construct( $locale ) {
if ( !extension_loaded( 'intl' ) ) {
throw new MWException( 'An ICU collation was requested, ' .
'but the intl extension is not available.' );
}
$this->locale = $locale;
$this->mainCollator = Collator::create( $locale );
if ( !$this->mainCollator ) {
throw new MWException( "Invalid ICU locale specified for collation: $locale" );
}
$this->primaryCollator = Collator::create( $locale );
$this->primaryCollator->setStrength( Collator::PRIMARY );
}
function getSortKey( $string ) {
// intl extension produces non null-terminated
// strings. Appending '' fixes it so that it doesn't generate
// a warning on each access in debug php.
wfSuppressWarnings();
$key = $this->mainCollator->getSortKey( $string ) . '';
wfRestoreWarnings();
return $key;
}
function getPrimarySortKey( $string ) {
wfSuppressWarnings();
$key = $this->primaryCollator->getSortKey( $string ) . '';
wfRestoreWarnings();
return $key;
}
function getFirstLetter( $string ) {
$string = strval( $string );
if ( $string === '' ) {
return '';
}
// Check for CJK
$firstChar = mb_substr( $string, 0, 1, 'UTF-8' );
if ( ord( $firstChar ) > 0x7f
&& self::isCjk( utf8ToCodepoint( $firstChar ) ) )
{
return $firstChar;
}
$sortKey = $this->getPrimarySortKey( $string );
// Do a binary search to find the correct letter to sort under
$min = $this->findLowerBound(
array( $this, 'getSortKeyByLetterIndex' ),
$this->getFirstLetterCount(),
'strcmp',
$sortKey );
if ( $min === false ) {
// Before the first letter
return '';
}
return $this->getLetterByIndex( $min );
}
function getFirstLetterData() {
if ( $this->firstLetterData !== null ) {
return $this->firstLetterData;
}
$cache = wfGetCache( CACHE_ANYTHING );
$cacheKey = wfMemcKey( 'first-letters', $this->locale );
$cacheEntry = $cache->get( $cacheKey );
if ( $cacheEntry ) {
$this->firstLetterData = $cacheEntry;
return $this->firstLetterData;
}
// Generate data from serialized data file
$letters = wfGetPrecompiledData( "first-letters-{$this->locale}.ser" );
if ( $letters === false ) {
throw new MWException( "MediaWiki does not support ICU locale " .
"\"{$this->locale}\"" );
}
// Sort the letters.
//
// It's impossible to have the precompiled data file properly sorted,
// because the sort order changes depending on ICU version. If the
// array is not properly sorted, the binary search will return random
// results.
//
// We also take this opportunity to remove primary collisions.
$letterMap = array();
foreach ( $letters as $letter ) {
$key = $this->getPrimarySortKey( $letter );
if ( isset( $letterMap[$key] ) ) {
// Primary collision
// Keep whichever one sorts first in the main collator
if ( $this->mainCollator->compare( $letter, $letterMap[$key] ) < 0 ) {
$letterMap[$key] = $letter;
}
} else {
$letterMap[$key] = $letter;
}
}
ksort( $letterMap, SORT_STRING );
$data = array(
'chars' => array_values( $letterMap ),
'keys' => array_keys( $letterMap )
);
// Reduce memory usage before caching
unset( $letterMap );
// Save to cache
$this->firstLetterData = $data;
$cache->set( $cacheKey, $data, 86400 * 7 /* 1 week */ );
return $data;
}
function getLetterByIndex( $index ) {
if ( $this->firstLetterData === null ) {
$this->getFirstLetterData();
}
return $this->firstLetterData['chars'][$index];
}
function getSortKeyByLetterIndex( $index ) {
if ( $this->firstLetterData === null ) {
$this->getFirstLetterData();
}
return $this->firstLetterData['keys'][$index];
}
function getFirstLetterCount() {
if ( $this->firstLetterData === null ) {
$this->getFirstLetterData();
}
return count( $this->firstLetterData['chars'] );
}
/**
* Do a binary search, and return the index of the largest item that sorts
* less than or equal to the target value.
*
* @param $valueCallback array A function to call to get the value with
* a given array index.
* @param $valueCount int The number of items accessible via $valueCallback,
* indexed from 0 to $valueCount - 1
* @param $comparisonCallback array A callback to compare two values, returning
* -1, 0 or 1 in the style of strcmp().
* @param $target string The target value to find.
*
* @return int|bool The item index of the lower bound, or false if the target value
* sorts before all items.
*/
function findLowerBound( $valueCallback, $valueCount, $comparisonCallback, $target ) {
$min = 0;
$max = $valueCount - 1;
do {
$mid = $min + ( ( $max - $min ) >> 1 );
$item = call_user_func( $valueCallback, $mid );
$comparison = call_user_func( $comparisonCallback, $target, $item );
if ( $comparison > 0 ) {
$min = $mid;
} elseif ( $comparison == 0 ) {
$min = $mid;
break;
} else {
$max = $mid;
}
} while ( $min < $max - 1 );
if ( $min == 0 && $max == 0 && $comparison > 0 ) {
// Before the first item
return false;
} else {
return $min;
}
}
static function isCjk( $codepoint ) {
foreach ( self::$cjkBlocks as $block ) {
if ( $codepoint >= $block[0] && $codepoint <= $block[1] ) {
return true;
}
}
return false;
}
}