nextcloud/lib/private/NaturalSort.php

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<?php
/**
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* @copyright Copyright (c) 2016, ownCloud, Inc.
*
* @author Arthur Schiwon <blizzz@arthur-schiwon.de>
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* @author AW-UC <git@a-wesemann.de>
* @author Christoph Wurst <christoph@winzerhof-wurst.at>
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* @author Lukas Reschke <lukas@statuscode.ch>
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* @author Morris Jobke <hey@morrisjobke.de>
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* @author Robin McCorkell <robin@mccorkell.me.uk>
* @author Vincent Petry <vincent@nextcloud.com>
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*
* @license AGPL-3.0
*
* This code is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License, version 3,
* along with this program. If not, see <http://www.gnu.org/licenses/>
*
*/
namespace OC;
use OCP\ILogger;
class NaturalSort {
private static $instance;
private $collator;
private $cache = [];
/**
* Instantiate a new \OC\NaturalSort instance.
* @param object $injectedCollator
*/
public function __construct($injectedCollator = null) {
// inject an instance of \Collator('en_US') to force using the php5-intl Collator
// or inject an instance of \OC\NaturalSort_DefaultCollator to force using Owncloud's default collator
if (isset($injectedCollator)) {
$this->collator = $injectedCollator;
\OCP\Util::writeLog('core', 'forced use of '.get_class($injectedCollator), ILogger::DEBUG);
}
}
/**
* Split the given string in chunks of numbers and strings
* @param string $t string
* @return array of strings and number chunks
*/
private function naturalSortChunkify($t) {
// Adapted and ported to PHP from
// http://my.opera.com/GreyWyvern/blog/show.dml/1671288
if (isset($this->cache[$t])) {
return $this->cache[$t];
}
$tz = [];
$x = 0;
$y = -1;
$n = null;
while (isset($t[$x])) {
$c = $t[$x];
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// only include the dot in strings
$m = ((!$n && $c === '.') || ($c >= '0' && $c <= '9'));
if ($m !== $n) {
// next chunk
$y++;
$tz[$y] = '';
$n = $m;
}
$tz[$y] .= $c;
$x++;
}
$this->cache[$t] = $tz;
return $tz;
}
/**
* Returns the string collator
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* @return \Collator string collator
*/
private function getCollator() {
if (!isset($this->collator)) {
// looks like the default is en_US_POSIX which yields wrong sorting with
// German umlauts, so using en_US instead
if (class_exists('Collator')) {
$this->collator = new \Collator('en_US');
} else {
$this->collator = new \OC\NaturalSort_DefaultCollator();
}
}
return $this->collator;
}
/**
* Compare two strings to provide a natural sort
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* @param string $a first string to compare
* @param string $b second string to compare
* @return int -1 if $b comes before $a, 1 if $a comes before $b
* or 0 if the strings are identical
*/
public function compare($a, $b) {
// Needed because PHP doesn't sort correctly when numbers are enclosed in
// parenthesis, even with NUMERIC_COLLATION enabled.
// For example it gave ["test (2).txt", "test.txt"]
// instead of ["test.txt", "test (2).txt"]
$aa = self::naturalSortChunkify($a);
$bb = self::naturalSortChunkify($b);
for ($x = 0; isset($aa[$x]) && isset($bb[$x]); $x++) {
$aChunk = $aa[$x];
$bChunk = $bb[$x];
if ($aChunk !== $bChunk) {
// test first character (character comparison, not number comparison)
if ($aChunk[0] >= '0' && $aChunk[0] <= '9' && $bChunk[0] >= '0' && $bChunk[0] <= '9') {
$aNum = (int)$aChunk;
$bNum = (int)$bChunk;
return $aNum - $bNum;
}
return self::getCollator()->compare($aChunk, $bChunk);
}
}
return count($aa) - count($bb);
}
/**
* Returns a singleton
* @return \OC\NaturalSort instance
*/
public static function getInstance() {
if (!isset(self::$instance)) {
self::$instance = new \OC\NaturalSort();
}
return self::$instance;
}
}