minor #36070 [Uid] improve base convertion logic (nicolas-grekas)

This PR was merged into the 5.1-dev branch.

Discussion
----------

[Uid] improve base convertion logic

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

The new logic is at least twice as fast as the current algo.
It's also way more common and generic.

Commits
-------

0e05c6d [Uid] improve base convertion logic

src/Symfony/Component/Uid/BinaryUtil.php

@@ -0,0 +1,97 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Uid;
+
+/**
+ * @internal
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class BinaryUtil
+{
+    public const BASE10 = [
+        '' => '0123456789',
+        0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
+    ];
+
+    public static function toBase(string $bytes, array $map): string
+    {
+        $base = \strlen($alphabet = $map['']);
+        $bytes = array_values(unpack(\PHP_INT_SIZE >= 8 ? 'n*' : 'C*', $bytes));
+        $digits = '';
+
+        while ($count = \count($bytes)) {
+            $quotient = [];
+            $remainder = 0;
+
+            for ($i = 0; $i !== $count; ++$i) {
+                $carry = $bytes[$i] + ($remainder << (\PHP_INT_SIZE >= 8 ? 16 : 8));
+                $digit = intdiv($carry, $base);
+                $remainder = $carry % $base;
+
+                if ($digit || $quotient) {
+                    $quotient[] = $digit;
+                }
+            }
+
+            $digits = $alphabet[$remainder].$digits;
+            $bytes = $quotient;
+        }
+
+        return $digits;
+    }
+
+    public static function fromBase(string $digits, array $map): string
+    {
+        $base = \strlen($map['']);
+        $count = \strlen($digits);
+        $bytes = [];
+
+        while ($count) {
+            $quotient = [];
+            $remainder = 0;
+
+            for ($i = 0; $i !== $count; ++$i) {
+                $carry = ($bytes ? $digits[$i] : $map[$digits[$i]]) + $remainder * $base;
+
+                if (\PHP_INT_SIZE >= 8) {
+                    $digit = $carry >> 16;
+                    $remainder = $carry & 0xFFFF;
+                } else {
+                    $digit = $carry >> 8;
+                    $remainder = $carry & 0xFF;
+                }
+
+                if ($digit || $quotient) {
+                    $quotient[] = $digit;
+                }
+            }
+
+            $bytes[] = $remainder;
+            $count = \count($digits = $quotient);
+        }
+
+        return pack(\PHP_INT_SIZE >= 8 ? 'n*' : 'C*', ...array_reverse($bytes));
+    }
+
+    public static function add(string $a, string $b): string
+    {
+        $carry = 0;
+        for ($i = 7; 0 <= $i; --$i) {
+            $carry += \ord($a[$i]) + \ord($b[$i]);
+            $a[$i] = \chr($carry & 0xFF);
+            $carry >>= 8;
+        }
+
+        return $a;
+    }
+}

src/Symfony/Component/Uid/Ulid.php

@@ -121,7 +121,7 @@ public function getTime(): float
             base_convert(substr($time, 6, 4), 32, 16)
         );
 
-        return InternalUtil::toDecimal(hex2bin($time)) / 1000;
+        return BinaryUtil::toBase(hex2bin($time), BinaryUtil::BASE10) / 1000;
     }
 
     public function __toString(): string
@@ -163,7 +163,7 @@ private static function generate(): string
         if (\PHP_INT_SIZE >= 8) {
             $time = base_convert($time, 10, 32);
         } else {
-            $time = bin2hex(InternalUtil::toBinary($time));
+            $time = bin2hex(BinaryUtil::fromBase($time, BinaryUtil::BASE10));
             $time = sprintf('%s%04s%04s',
                 base_convert(substr($time, 0, 2), 16, 32),
                 base_convert(substr($time, 2, 5), 16, 32),

src/Symfony/Component/Uid/Uuid.php

@@ -121,10 +121,10 @@ public function getTime(): float
         }
 
         $time = str_pad(hex2bin($time), 8, "\0", STR_PAD_LEFT);
-        $time = InternalUtil::binaryAdd($time, self::TIME_OFFSET_COM);
+        $time = BinaryUtil::add($time, self::TIME_OFFSET_COM);
         $time[0] = $time[0] & "\x7F";
 
-        return InternalUtil::toDecimal($time) / 10000000;
+        return BinaryUtil::toBase($time, BinaryUtil::BASE10) / 10000000;
     }
 
     public function getMac(): string