PHP网站开发面试题

// bind：每次resolve都创建新实例
$this-app-bind(ServiceInterface::class, ServiceImpl::class);
// singleton：仅首次创建，后续复用
$this-app-singleton(ServiceInterface::class, ServiceImpl::class);
// 实际效果
$a = $this-app-make(ServiceInterface::class);
$b = $this-app-make(ServiceInterface::class);
var_dump($a === $b); // bind: false | singleton: true
            

$this-app-singleton(ServiceInterface::class, function ($app) {
    return new ServiceImpl(
        $app-make(RepositoryInterface::class)
    );
});

class UserEventListener {
    public function onUserRegistered(UserRegisteredEvent $event) {
        // 发送欢迎邮件
    }
    public static function getSubscribedEvents() {
        return [
            UserRegisteredEvent::class => ['onUserRegistered', 10]
        ];
    }
}
            

class UserEventSubscriber implements EventSubscriberInterface {
    public static function getSubscribedEvents() {
        return [
            UserRegisteredEvent::class => 'onRegister',
            UserLoggedInEvent::class => 'onLogin',
        ];
    }
    public function onRegister(UserRegisteredEvent $event) { ... }
    public function onLogin(UserLoggedInEvent $event) { ... }
}
            

// 1. 验证MIME类型
$finfo = finfo_open(FILEINFO_MIME_TYPE);
$mime = finfo_file($finfo, $_FILES['file']['tmp_name']);
finfo_close($finfo);
if (!in_array($mime, ['image/jpeg', 'image/png'])) {
    throw new Exception('Invalid file type');
}
// 2. 生成随机文件名
$ext = pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION);
$safeName = uniqid() . '.' . strtolower($ext);
// 3. 移动到安全目录
$uploadPath = '/data/uploads'; // 非Web目录
move_uploaded_file($_FILES['file']['tmp_name'], $uploadPath . '/' . $safeName);
// 4. Nginx配置禁止执行
# location /uploads {
#   php_admin_value engine off;
# }
            

// 1. 尝试获取互斥锁
$lockKey = 'lock:' . $key;
$acquired = $redis-setnx($lockKey, 1);
$redis-expire($lockKey, 10); // 防死锁
if ($acquired) {
    // 2. 查询数据库
    $data = queryDB($key);
    $redis-set($key, $data);
    $redis-del($lockKey);
} else {
    // 3. 等待后重试
    usleep(50000); // 50ms
    return getFromCache($key);
}
            

// 慢查询示例
SELECT * FROM orders WHERE user_id = 12345 LIMIT 1000000, 10;
// 优化方案：延迟关联
SELECT o.* FROM orders o
INNER JOIN (
    SELECT id FROM orders WHERE user_id = 12345 LIMIT 1000000, 10
) tmp ON o.id = tmp.id;
            

; php.ini 关键配置
opcache.enable=1                     // 启用OPcache
opcache.memory_consumption=256      // 内存大小（MB）
opcache.max_accelerated_files=20000 // 最大缓存文件数
opcache.validate_timestamps=0     // 生产环境禁用时间戳检查
opcache.save_comments=0            // 移除注释减少体积
            

// Redis + Lua方案（原子性保障）
$script = <<
local stock = redis.call('GET', KEYS[1]);
if (tonumber(stock) > 0) then
    redis.call('DECR', KEYS[1]);
    return 1;
else
    return 0;
end;
LUA;
$result = $redis-eval($script, ['stock:product:123'], 1);
            

# 使用官方PHP镜像作为基础
FROM php:8.2-cli-alpine
# 安装扩展
RUN apk add --no-cache libzip-dev zip \
    && docker-php-ext-install pdo_mysql \
    && pecl install redis \
    && docker-php-ext-enable redis
# 设置工作目录
WORKDIR /var/www
# 复制代码
COPY composer.json composer.lock ./
RUN composer install --optimize-autoloader --no-dev
COPY . .
# 非root用户运行
RUN addgroup -g 1000 -S www && adduser -u 1000 -S www -G www
USER www
# 暴露端口
EXPOSE 8080
# 启动命令
CMD ["php", "-S", "0.0.0.0:8080", "-t", "public"]