php Cache 类

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1、实例化

$cache = new Cache();
　　2、设置缓存时间和缓存目录

$cache = new Cache(60, '/any_other_path/');
　　第一个参数是缓存秒数，第二个参数是缓存路径，根据需要配置。

默认情况下，缓存时间是 3600 秒，缓存目录是 cache/
　　3、读取缓存

$value = $cache->get('data_key');
　　4、写入缓存

$value = $cache->put('data_key', 'data_value');
　　完整实例：

$cache = new Cache();
//从缓存从读取键值 $key 的数据
$values = $cache->get($key);
//如果没有缓存数据
if ($values == false) {
//insert code here...
//写入键值 $key 的数据
$cache->put($key, $values);
} else {
//insert code here...
}

　　<?php
class Cache {private $cache_path;//path for the cacheprivate $cache_expire;//seconds that the cache expires//cache constructor, optional expiring time and cache pathpublic function Cache($exp_time=3600,$path="cache/"){$this->cache_expire=$exp_time;$this->cache_path=$path;}//returns the filename for the cacheprivate function fileName($key){return $this->cache_path.md5($key);}//creates new cache files with the given data, $key== name of the cache, data the info/values to storepublic function put($key, $data){$values = serialize($data);$filename = $this->fileName($key);$file = fopen($filename, 'w');if ($file){//able to create the filefwrite($file, $values);fclose($file);}else return false;}//returns cache for the given keypublic function get($key){$filename = $this->fileName($key);if (!file_exists($filename) || !is_readable($filename)){//can't read the cachereturn false;}if ( time() < (filemtime($filename) + $this->cache_expire) ) {//cache for the key not expired$file = fopen($filename, "r");// read data fileif ($file){//able to open the file$data = fread($file, filesize($filename));fclose($file);return unserialize($data);//return the values}else return false;}else return false;//was expired you need to create new}
}
?>