缓存readdir() [英] Caching readdir()

问题描述

是否仍然要缓存readdir()结果?现在，每次我在网站上输入特定网页时，我都会在目录树上执行readdir().

Is there anyway to cache readdir() result? Right now I do readdir() on a directory tree everytime I enter a specific webpage on the website.

更新:

• 所有用户的目录结构相同.
• 不幸的是，我的共享主机不支持APC或内存缓存:-(

推荐答案

您可以将Memcache与filemtime

$path = __DIR__ . "/test";
$cache = new Memcache();
$cache->addserver("localhost");

$key = sha1($path);
$info = $cache->get(sha1($path));

if ($info && $info->time == filemtime($path)) {
    echo "Cache Copy ", date("Y-m-d g:i:s", $info->time);
} else {
    $info = new stdClass();
    $info->readDir = array_map("strval", iterator_to_array(new FilesystemIterator($path, FilesystemIterator::SKIP_DOTS)));
    $info->time = filemtime($path);
    $cache->set($key, $info, MEMCACHE_COMPRESSED, 0);
    echo "Path Changed ", date("Y-m-d g:i:s", $info->time);
}

var_dump(array_values($info->readDir));

更新

不幸的是，我的共享主机不支持APC或内存缓存:-(

Unfortunately my shared host do not support APC or memcache :-(

您可以使用文件系统

$path = __DIR__ . "/test";
$cache = new MyCache(__DIR__ . "/a");

$key = sha1($path);
$info = $cache->get($key);

if ($info && $info->time == filemtime($path)) {
    echo "Cache Copy ", date("Y-m-d g:i:s", $info->time);
} else {
    $info = new stdClass();
    $info->readDir = array_map("strval", iterator_to_array(new FilesystemIterator($path, FilesystemIterator::SKIP_DOTS)));
    $info->time = filemtime($path);
    $cache->set($key, $info, MEMCACHE_COMPRESSED, 0);
    echo "Path Changed ", date("Y-m-d g:i:s", $info->time);
}

var_dump(array_values((array) $info->readDir));

使用的类

class MyCache {
    private $path;

    function __construct($path) {
        is_writable($path) or trigger_error("Path Not Writeable");
        is_dir($path) or trigger_error("Path Not a Directory");
        $this->path = $path;
    }

    function get($key) {
        $file = $this->path . DIRECTORY_SEPARATOR . $key . ".cache";
        if (! is_file($file))
            return false;
        $data = file_get_contents($file);
        substr($data, 0, 2) == "##" and $data = gzinflate(substr($data, 2));
        return json_decode($data);
    }

    function set($key, $value, $compression = 0) {
        $data = json_encode($value);
        $compression and $data = gzdeflate($data, 9) and $data = "##" . $data;
        return file_put_contents($this->path . DIRECTORY_SEPARATOR . $key . ".cache", $data);
    }
}

这篇关于缓存readdir()的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！