mirror of
https://github.com/Part-DB/Part-DB-server.git
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116 lines
No EOL
3.8 KiB
PHP
116 lines
No EOL
3.8 KiB
PHP
<?php
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/**
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*
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* part-db version 0.1
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* Copyright (C) 2005 Christoph Lechner
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* http://www.cl-projects.de/
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*
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* part-db version 0.2+
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* Copyright (C) 2009 K. Jacobs and others (see authors.php)
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* http://code.google.com/p/part-db/
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*
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* Part-DB Version 0.4+
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* Copyright (C) 2016 - 2019 Jan Böhmer
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* https://github.com/jbtronics
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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*
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*/
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namespace App\Services;
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/**
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* A service that helps you to format values using the SI prefixes.
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* @package App\Services
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*/
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class SIFormatter
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{
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/**
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* Returns the magnitude of a value (the count of decimal place of the highest decimal place).
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* For example, for 100 (=10^2) this function returns 2. For -2500 (=-2.5*10^3) this function returns 3.
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* @param float $value The value of which the magnitude should be determined.
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* @return int The magnitude of the value
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*/
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public function getMagnitude(float $value) : int
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{
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return (int) floor(log10(abs($value)));
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}
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/**
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* Returns the best SI prefix (and its corresponding divisor) for the given magnitude.
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* @param int $magnitude The magnitude for which the prefix should be determined.
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* @return array A array, containing the divisor in first element, and the prefix symbol in second. For example, [1000, "k"].
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*/
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public function getPrefixByMagnitude(int $magnitude) : array
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{
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$prefixes_pos = ['' ,'k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'];
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$prefixes_neg = ['' ,'m', 'μ', 'n', 'p', 'f', 'a', 'z', 'y'];
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if ($magnitude >= 0) {
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$nearest = (int) floor(abs($magnitude) / 3);
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$symbol = $prefixes_pos[$nearest];
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} else {
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$nearest = (int) round(abs($magnitude) / 3);
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$symbol = $prefixes_neg[$nearest];
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}
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if ($magnitude < 0) {
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$nearest *= -1;
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}
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return [10 ** (3 * $nearest), $symbol];
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}
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/**
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*
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* @param float $value
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* @return array
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*/
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public function convertValue(float $value) : array
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{
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//Choose the prefix to use
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$tmp = $this->getPrefixByMagnitude($this->getMagnitude($value));
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$ret = array(
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'value' => $value / $tmp[0],
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'prefix_magnitude' => log10($tmp[0]),
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'prefix' => $tmp[1]
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);
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return $ret;
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}
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/**
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* Formats the given value to a string, using the given options
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* @param float $value The value that should be converted
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* @param string $unit The unit that should be appended after the prefix
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* @param int $decimals The number of decimals (after decimal dot) that should be outputed.
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* @return string
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*/
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public function format(float $value, string $unit = '', int $decimals = 2) : string
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{
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[$divisor, $symbol] = $this->getPrefixByMagnitude($this->getMagnitude($value));
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$value /= $divisor;
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//Build the format string, e.g.: %.2d km
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if ($unit !== '' || $symbol !== '') {
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$format_string = '%.' . $decimals . 'f ' . $symbol . $unit;
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} else {
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$format_string = '%.' . $decimals . 'f';
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}
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return sprintf($format_string, $value);
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}
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} |