php如何实现动态加载配置文件_php按需读取不同环境配置与缓存避免重复io

$env = getenv('APP_ENV') ?: 'dev';
$configFile = "config/{$env}.php";

if (file_exists($configFile)) {
    $config = require $configFile;
} else {
    throw new RuntimeException("Config file for environment '{$env}' not found.");
}

class Config
{
    private static $cache = [];
    private static $loaded = [];

    public static function get($key, $default = null)
    {
        // 解析 key，如 database.host
        [$group, $item] = explode('.', $key, 2) + [1 => null];

        if (!isset(self::$loaded[$group])) {
            self::load($group);
        }

        return self::$cache[$group][$item] ?? $default;
    }

    private static function load($group)
    {
        $env = getenv('APP_ENV') ?: 'dev';
        $file = "config/{$group}.{$env}.php";

        if (file_exists($file)) {
            self::$cache[$group] = require $file;
        } elseif (file_exists("config/{$group}.php")) {
            self::$cache[$group] = require "config/{$group}.php";
        } else {
            self::$cache[$group] = [];
        }
        self::$loaded[$group] = true;
    }
}

private static function loadWithCache($group)
{
    $env = getenv('APP_ENV') ?: 'dev';
    $cacheKey = "config.{$group}.{$env}";

    if (function_exists('apcu_fetch')) {
        $cached = apcu_fetch($cacheKey);
        if ($cached !== false) {
            self::$cache[$group] = $cached;
            return;
        }
    }

    // 正常加载
    $file = "config/{$group}.{$env}.php";
    if (file_exists($file)) {
        $config = require $file;
    } elseif (file_exists("config/{$group}.php")) {
        $config = require "config/{$group}.php";
    } else {
        $config = [];
    }

    self::$cache[$group] = $config;

    if (function_exists('apcu_store')) {
        apcu_store($cacheKey, $config);
    }
}

// build-config.php
$env = 'prod';
$config = [];

foreach (glob("config/*.{$env}.php") as $file) {
    $key = basename($file, ".{$env}.php");
    $config[$key] = require $file;
}

$content = "<?php\nreturn " . var_export($config, true) . ";\n";
file_put_contents('config/compiled.php', $content);

$config = require 'config/compiled.php';