Performance optimizations

[GromNaN]

• Use use function to enable compiler optimization of some native functions.
• Use preg_match('/(.).*\1/', $alphabet) to validate there is no duplicate char, faster than splitting into an array
• Avoid splitting strings, and access chars directly with $string[$char]
• Avoid functions with callback (array_reduce, array_filter), they are slower than foreach

Benchmark

PHPBench code

composer req --dev phpbench/phpbench

In phpbench.json

{
    "$schema": "./vendor/phpbench/phpbench/phpbench.schema.json",
    "runner.bootstrap": "vendor/autoload.php",
    "runner.file_pattern": "*Bench.php",
    "runner.path": "tests",
    "runner.iterations": 3
}

In tests/SqidsBench.php

<?php

namespace Sqids\Benchmark;

use PhpBench\Attributes\ParamProviders;
use PhpBench\Attributes\Revs;
use PhpBench\Attributes\Warmup;
use Sqids\Sqids;

#[Warmup(1)]
final class SqidsBench
{
    private const IDS = [
        'SvIzsqYMyQwI3GWgJAe17URxX8V924Co0DaTZLtFjHriEn5bPhcSkfmvOslpBu' => [0, 0],
        'n3qafPOLKdfHpuNw3M61r95svbeJGk7aAEgYn4WlSjXURmF8IDqZBy0CT2VxQc' => [0, 1],
        'tryFJbWcFMiYPg8sASm51uIV93GXTnvRzyfLleh06CpodJD42B7OraKtkQNxUZ' => [0, 2],
        'eg6ql0A3XmvPoCzMlB6DraNGcWSIy5VR8iYup2Qk4tjZFKe1hbwfgHdUTsnLqE' => [0, 3],
        'rSCFlp0rB2inEljaRdxKt7FkIbODSf8wYgTsZM1HL9JzN35cyoqueUvVWCm4hX' => [0, 4],
        'sR8xjC8WQkOwo74PnglH1YFdTI0eaf56RGVSitzbjuZ3shNUXBrqLxEJyAmKv2' => [0, 5],
        'uY2MYFqCLpgx5XQcjdtZK286AwWV7IBGEfuS9yTmbJvkzoUPeYRHr4iDs3naN0' => [0, 6],
        '74dID7X28VLQhBlnGmjZrec5wTA1fqpWtK4YkaoEIM9SRNiC3gUJH0OFvsPDdy' => [0, 7],
        '30WXpesPhgKiEI5RHTY7xbB1GnytJvXOl2p0AcUjdF6waZDo9Qk8VLzMuWrqCS' => [0, 8],
        'moxr3HqLAK0GsTND6jowfZz3SUx7cQ8aC54Pl1RbIvFXmEJuBMYVeW9yrdOtin' => [0, 9],
        'JSwXFaosANEOuLlYb3jHCBpeSzx7cPRrgf1dNTZqE4nDytU09isA5ahm6kKGvM' => [1_000_000, 2_000_000],
    ];

    #[Revs(1_000)]
    #[ParamProviders('provideSqids')]
    public static function benchEncodeDecode(array $params): void
    {
        foreach (self::IDS as $id => $numbers) {
            $params[0]->encode($numbers);
            $params[0]->decode($id);
        }
    }

    public static function provideSqids(): \Generator
    {
        yield 'default' => [
            new Sqids()
        ];
        yield 'custom blocklist' => [
            new Sqids(blocklist: [
                'JSwXFaosAN',
                'OCjV9JK64o',
                'rBHf',
                '79SM',
                '7tE6',
            ])
        ];
        yield 'no blocklist' => [
            new Sqids(blocklist: [])
        ];
    }
}

Before

    benchEncodeDecode # default.............I2 - Mo2.195ms (±0.47%)
    benchEncodeDecode # custom blocklist....I2 - Mo1.099ms (±0.84%)
    benchEncodeDecode # no blocklist........I2 - Mo929.423μs (±0.87%)

After

    benchEncodeDecode # default.............I2 - Mo994.363μs (±0.35%)
    benchEncodeDecode # custom blocklist....I2 - Mo681.353μs (±0.36%)
    benchEncodeDecode # no blocklist........I2 - Mo552.545μs (±0.21%)

[vinkla]

This looks good to me. I'll leave it up to @4kimov to merge this who has a deeper knowledge across our language implementations.