[lonnieezell]

Description
Fixes #10617

Without route caching, the route table is rebuilt on every request. This PR removes two pieces of mostly wasted work from RouteCollection::create(), which runs once per registered route:

• Placeholder loop: the str_ireplace(':' . $tag, ...) loop now runs only when the route key contains :. Every placeholder search string starts with :, so a key without one cannot match. The output is identical.
• helper('array'): this is now called only on the first create() of each collection, using a private flag. RouteCollection no longer uses the helper, but the helper still loads at the same point as before, so apps that rely on that side effect keep working.

There are no public or protected API changes, and the route table is unchanged (same keys, handlers, names and options).

Benchmark

Time to build the route table on 4.8: PHP 8.3.23 CLI on macOS, OPcache on, production mode, a new RouteCollection per build. The routes are a realistic mix: a third static, a third with one placeholder, a third with two, in groups of 10. Before and after were run alternately for 4 rounds. Each round takes the median of 7 timed runs, and the table shows the median across rounds.

Routes	Before	After	Saved	Per route
30	77.8 µs	65.7 µs	16%	2.59 → 2.19 µs
100	228.3 µs	189.9 µs	17%	2.28 → 1.90 µs
300	685.9 µs	556.0 µs	19%	2.29 → 1.85 µs
1000	2,309 µs	1,814 µs	21%	2.31 → 1.81 µs

Comparing the fastest round on each side gives similar savings (14–19%). The same benchmark on develop showed 17–19% savings (2.05 → 1.69 µs per route).

The issue estimated about 40%, but that assumed every route skips the placeholder loop. In this mix only the static third does, so the expected saving is about 0.5 µs × ⅓ + 0.24 µs ≈ 0.41 µs per route, which is close to the 0.4–0.5 µs measured. Apps with mostly static routes will save more.

Benchmark script

<?php

declare(strict_types=1);

$_SERVER['CI_ENVIRONMENT'] = 'production';
require getcwd() . '/system/Test/bootstrap.php';

use CodeIgniter\Router\RouteCollection;
use Config\Modules;
use Config\Routing;

function build(RouteCollection $routes, int $n): void
{
    $perGroup = 10;

    for ($g = 0; $g < intdiv($n, $perGroup); $g++) {
        $routes->group("grp{$g}", static function (RouteCollection $routes) use ($g, $perGroup): void {
            for ($i = 0; $i < $perGroup; $i++) {
                $k = $g * $perGroup + $i;

                match ($k % 3) {
                    0 => $routes->get("static{$k}/page", "Ctrl{$g}::m{$i}"),
                    1 => $routes->get("one{$k}/(:num)", "Ctrl{$g}::m{$i}/$1"),
                    2 => $routes->post("two{$k}/(:segment)/(:num)", "Ctrl{$g}::m{$i}/$1/$2"),
                };
            }
        });
    }
}

$modules          = new Modules();
$modules->enabled = false;
$routing          = new Routing();

foreach ([30, 100, 300, 1000] as $n) {
    $iterations = max(200, intdiv(200_000, $n));
    $samples    = [];

    for ($run = 0; $run < 7; $run++) {
        $start = hrtime(true);

        for ($it = 0; $it < $iterations; $it++) {
            $routes = new RouteCollection(service('locator'), $modules, $routing);
            build($routes, $n);
        }

        $samples[] = (hrtime(true) - $start) / $iterations / 1000;
    }

    sort($samples);
    printf("%5d routes: %8.1f µs/build  %5.2f µs/route\n", $n, $samples[3], $samples[3] / $n);
}

Run it from the repo root with php -d opcache.enable_cli=1 bench_routes.php.

Tests

New tests in RouteCollectionTest lock in current behavior. All three pass both before and after the change:

• A route with no placeholders, including a raw regex, keeps its exact key.
• A custom placeholder containing (?:...), mixed with built-in placeholders, still expands correctly.
• Placeholders still match case-insensitively and without parentheses ((:NUM), :segment). The : guard relies on this behavior.

No changelog or user guide entry is included, as planned in the issue.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value (without duplication)
• Unit testing, with >80% coverage
• User guide updated (not needed: no user-facing change)
• Conforms to style guide

🤖 Generated with Claude Code

[michalsn]

Looks good to me - I also ran benchmarks locally and saw similar improvements.

Could we add a changelog entry under “Changes”? Something like this would work:

• Router: Reduced route registration overhead in RouteCollection::create() by skipping placeholder replacement for route keys without : and calling helper('array') only once per collection.

[lonnieezell]

Oh, yeah, completely forgot the change log. Incoming.