php如何实现缓存类代码

本文操作环境：windows10系统、PHP 7、thinkpad t480电脑。

使用说明：

实例化

$cache = new Cache();

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/

读取缓存

$value = $cache->get('data_key');

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...
}

Cache.class.php

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