PHP 데이터 캐시에 대한 영구 저장 및 복구 전략 분석

function cache_get($key) {
    $cache_dir = '/path/to/cache/dir/';
    $file = $cache_dir . md5($key);
    
    if (file_exists($file)) {
        $data = file_get_contents($file);
        $cache = unserialize($data);
        if ($cache['expire'] < time()) {
            unlink($file);
            return false;
        }
        return $cache['data'];
    }
    return false;
}

function cache_set($key, $data, $expire = 3600) {
    $cache_dir = '/path/to/cache/dir/';
    $file = $cache_dir . md5($key);
    $cache = [
        'expire' => time() + $expire,
        'data' => $data
    ];
    $data = serialize($cache);
    file_put_contents($file, $data);
}

function cache_get($key) {
    $db_host = 'localhost';
    $db_user = 'root';
    $db_password = 'password';
    $db_name = 'cache_db';
    
    $conn = mysqli_connect($db_host, $db_user, $db_password, $db_name);
    if (!$conn) {
        die('Database connection failed: ' . mysqli_connect_error());
    }
    
    $sql = "SELECT data FROM cache_table WHERE `key` = '$key' AND expire >= NOW()";
    $result = mysqli_query($conn, $sql);
    
    if (mysqli_num_rows($result) > 0) {
        $row = mysqli_fetch_assoc($result);
        return $row['data'];
    }
    
    return false;
}

function cache_set($key, $data, $expire = 3600) {
    $db_host = 'localhost';
    $db_user = 'root';
    $db_password = 'password';
    $db_name = 'cache_db';
    
    $conn = mysqli_connect($db_host, $db_user, $db_password, $db_name);
    if (!$conn) {
        die('Database connection failed: ' . mysqli_connect_error());
    }
    
    $expire_date = date('Y-m-d H:i:s', time() + $expire);
    $data = mysqli_real_escape_string($conn, $data);
    
    $sql = "INSERT INTO cache_table (`key`, data, expire) VALUES ('$key', '$data', '$expire_date')";
    mysqli_query($conn, $sql);
}

function cache_get($key) {
    $cacheObj = new Memcached();
    $cacheObj->addServer('localhost', 11211);
    
    $data = $cacheObj->get($key);
    return $data;
}

function cache_set($key, $data, $expire = 3600) {
    $cacheObj = new Memcached();
    $cacheObj->addServer('localhost', 11211);
    
    $cacheObj->set($key, $data, $expire);
}