PHP中封装性的缓存策略和技术

class FileCache {
    private $cacheDir;

    public function __construct($cacheDir) {
        $this->cacheDir = $cacheDir;
    }

    public function get($key) {
        $filename = $this->getFilename($key);

        if (file_exists($filename)) {
            $data = file_get_contents($filename);
            return unserialize($data);
        }

        return false;
    }

    public function set($key, $value) {
        $filename = $this->getFilename($key);
        $data = serialize($value);
        file_put_contents($filename, $data);
    }

    private function getFilename($key) {
        return $this->cacheDir . '/' . md5($key);
    }
}

$cache = new FileCache('/path/to/cache');
$data = $cache->get('my_data');

if (!$data) {
    $data = // 从数据库或其他地方获取数据
    $cache->set('my_data', $data);
}

// 使用 $data 进行后续操作

class MemcachedCache {
    private $memcached;

    public function __construct() {
        $this->memcached = new Memcached();
        $this->memcached->addServer('localhost', 11211);
    }

    public function get($key) {
        return $this->memcached->get($key);
    }

    public function set($key, $value, $expire = 0) {
        return $this->memcached->set($key, $value, $expire);
    }
}

$cache = new MemcachedCache();
$data = $cache->get('my_data');

if (!$data) {
    $data = // 从数据库或其他地方获取数据
    $cache->set('my_data', $data);
}

// 使用 $data 进行后续操作

class RedisCache {
    private $redis;

    public function __construct($host, $port) {
        $this->redis = new Redis();
        $this->redis->connect($host, $port);
    }

    public function get($key) {
        return $this->redis->get($key);
    }

    public function set($key, $value, $expire = 0) {
        if ($expire > 0) {
            return $this->redis->setex($key, $expire, $value);
        } else {
            return $this->redis->set($key, $value);
        }
    }
}

$cache = new RedisCache('localhost', 6379);
$data = $cache->get('my_data');

if (!$data) {
    $data = // 从数据库或其他地方获取数据
    $cache->set('my_data', $data);
}

// 使用 $data 进行后续操作