Boost PHP Routing Performance with FastRoute: A Step‑by‑Step Guide

Overview

FastRoute is a lightweight PHP routing library that focuses on performance by compiling all route information once, avoiding costly string‑matching on each request, and using regular‑expression‑based routing.

Create a New Project

mkdir HelloFastRoute
cd HelloFastRoute

Initialize Composer

Run composer init in the project directory to generate a composer.json file. Define the package name, author, and PSR‑4 autoload mapping for the Tinywan\HelloFastRoute\ namespace pointing to src/.

Install FastRoute

composer require nikic/fast-route

Configure Routes

Create an index.php file and add the following code:

<?php
declare(strict_types=1);
require 'vendor/autoload.php';

$dispatcher = FastRoute\simpleDispatcher(function (FastRoute\RouteCollector $r) {
    $r->addRoute('GET', '/user/{userId}/info', function ($args) {
        echo '[x][开源技术小栈] User ID: ' . $args['userId'];
    });
});

$httpMethod = $_SERVER['REQUEST_METHOD'];
$uri = $_SERVER['REQUEST_URI'];
if (false !== $pos = strpos($uri, '?')) {
    $uri = substr($uri, 0, $pos);
}
$uri = rawurldecode($uri);

$routeInfo = $dispatcher->dispatch($httpMethod, $uri);
switch ($routeInfo[0]) {
    case FastRoute\Dispatcher::NOT_FOUND:
        http_response_code(404);
        echo "404 Not Found";
        break;
    case FastRoute\Dispatcher::METHOD_NOT_ALLOWED:
        http_response_code(405);
        echo "405 Method Not Allowed";
        break;
    case FastRoute\Dispatcher::FOUND:
        $handler = $routeInfo[1];
        $vars = $routeInfo[2];
        call_user_func($handler, $vars);
        break;
}

Start PHP's built‑in server from the project directory: php -S localhost:8888 Visiting http://localhost:8888/user/2024/info will output:

[x][开源技术小栈] User ID: 2024

Code Analysis

The call_user_func function invokes a callback with supplied arguments. In the routing example it executes the anonymous function defined in addRoute when the URL matches the pattern. $routeInfo[0] holds the dispatch result (e.g., FastRoute\Dispatcher::FOUND). $routeInfo[1] contains the handler – the anonymous function associated with the matched route. $routeInfo[2] is an associative array of route parameters extracted from the URL (e.g., ['userId' => '2024']).

When a request matches /user/{userId}/info, the dispatcher returns FOUND, the handler is retrieved, and call_user_func($handler, $vars) runs the function, printing the user ID.

Specifically, the anonymous function is defined in the addRoute call and stored as $handler . The extracted $vars are passed to it, enabling dynamic handling based on URL parameters.