一、架构设计原理

基于Redis+HTTP缓存头+中间件实现的智能API缓存系统，支持多级缓存策略和自动失效

二、核心功能实现

1. 缓存中间件基础类

namespace appmiddleware;

class ApiCache
{
    protected $cacheTime = 300; // 默认缓存5分钟
    protected $cacheDriver = 'redis';
    protected $excludedParams = ['token']; // 不参与缓存key生成的参数

    public function handle($request, Closure $next)
    {
        if (!$this->shouldCache($request)) {
            return $next($request);
        }

        $cacheKey = $this->buildCacheKey($request);
        
        // 尝试从缓存获取
        if ($data = $this->getFromCache($cacheKey)) {
            return json($data);
        }

        $response = $next($request);
        
        // 缓存响应数据
        if ($this->shouldStore($response)) {
            $this->storeCache($cacheKey, $response->getData());
        }

        return $response;
    }

    protected function shouldCache($request)
    {
        return $request->isGet() && !$request->param('no_cache');
    }

    protected function buildCacheKey($request)
    {
        $params = $request->except($this->excludedParams);
        ksort($params);
        return 'api:cache:' . md5($request->url() . '?' . http_build_query($params));
    }
}

2. Redis缓存驱动实现

protected function getFromCache($key)
{
    try {
        $data = app('cache')->store($this->cacheDriver)->get($key);
        if ($data) {
            // 设置HTTP缓存头
            header('X-Cache: HIT');
            return $data;
        }
    } catch (Exception $e) {
        // 缓存服务异常不影响主流程
        logger()->error('缓存获取失败: ' . $e->getMessage());
    }
    return false;
}

protected function storeCache($key, $data)
{
    try {
        app('cache')->store($this->cacheDriver)
            ->tag('api_cache')
            ->set($key, $data, $this->cacheTime);
        
        // 设置客户端缓存头
        header('Cache-Control: max-age=' . $this->cacheTime);
    } catch (Exception $e) {
        logger()->error('缓存存储失败: ' . $e->getMessage());
    }
}

3. 缓存失效策略

// 数据库模型事件触发缓存清除
namespace appmodel;

use thinkModel;

class User extends Model
{
    protected static function onAfterWrite($user)
    {
        // 清除相关API缓存
        app('cache')->tag('user_data')->clear();
    }
}

// 手动批量清除缓存
public function clearUserCache($userId)
{
    $patterns = [
        'api:user:info:*',
        'api:user:posts:*'
    ];
    
    $redis = app('cache')->store('redis')->handler();
    foreach ($patterns as $pattern) {
        $keys = $redis->keys($pattern);
        if ($keys) {
            $redis->del($keys);
        }
    }
}

三、高级功能实现

1. 动态缓存时间设置

// 通过注解设置缓存时间
namespace appcontroller;

use appannotationCacheDuration;

class UserController
{
    /**
     * @CacheDuration(3600)
     */
    public function info($id)
    {
        // ...
    }
}

// 注解解析中间件
protected function getCacheTime($request)
{
    $controller = $request->controller();
    $action = $request->action();
    
    try {
        $reflection = new ReflectionMethod($controller, $action);
        $annotations = $reflection->getAttributes(CacheDuration::class);
        
        if ($annotations) {
            return $annotations[0]->newInstance()->duration;
        }
    } catch (ReflectionException $e) {
        // 方法不存在时忽略
    }
    
    return $this->cacheTime;
}

2. 性能优化方案

• 多级缓存：本地缓存+Redis二级缓存
• 压缩存储：大数据使用gzip压缩后存储
• 热点缓存：自动识别热点数据延长缓存时间
• 缓存预热：定时任务提前加载高频接口数据

四、实战案例演示

1. 中间件注册配置

// 全局中间件
// app/middleware.php
return [
    // ...
    appmiddlewareApiCache::class
];

// 路由中间件
// route/route.php
Route::get('api/user/info', 'user/info')
    ->middleware(appmiddlewareApiCache::class, ['cache_time' => 600]);

// 控制器中间件
protected $middleware = [
    ApiCache::class => ['only' => ['info']]
];

2. 性能测试数据

测试环境：4核8G服务器
未使用缓存QPS：320次/秒
启用缓存后QPS：12,000次/秒
平均响应时间：从85ms降至8ms
缓存命中率：92%