Example of using file cache in php-PHP Tutorial-php.cn

Example of using file cache in php

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Release： 2016-07-25 08:45:22

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In web development, file caching can be used to greatly alleviate the pressure on the database. The following code is an example of using file caching in php.

CacheLayer.php

class CacheLayer{
protected $root = "";
protected $cache = "";
protected $key = "";
protected $life = 0;
public function __construct($key, $root = "/cachelayer"){
$this->root = $_SERVER["DOCUMENT_ROOT"].$root;
$this->key = $key;
}
public function expired($life_span){
$this->life = $life_span;
$file = $this->root."/".$this->key.".cachelayer";
if(is_file ($file)){
$mtime = filemtime($file);
return (time() >= ($mtime + $this->life));
}else{
return true;
}
}
public function put($content){
$file = $this->root."/".$this->key.".cachelayer";
if(!is_dir(dirname($this->root ))){
return false;
}
$this->delete();
$content = json_encode($content);
return (bool)file_put_contents($file, $content);
}
public function get (){
$file = $this->root."/".$this->key.".cachelayer";
if(is_file($file)){
return json_decode(file_get_contents($file), true);
}
return array();
}
public function delete(){
$file = $this->root."/".$this->key.".cachelayer";
if( is_file($file)){
unlink($file);
return true;
}
return false;
}
}

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example.php

// Load the cachelayer and the database connection (db connection is optional)
require_once "CacheLayer.php";
require_once "db_connection.php";
/ / Create a instance of the cachelayer
$cl_nav = new CacheLayer("navigation");
// Check to see if the cache is expired (60 * 10 = 10 minutes)
if($cl_nav->expired(60 * 10)){
echo "Cache doesn't exist or is expired. Rebuilding...
";
// if the cache is expired rebuild it
$result = mysql_query("select id, title from navigation");
$new_cache = array();
while($row = mysql_fetch_assoc($result)){
$new_cache[] = $row;
}
// Save the array into the cache
$cl_nav-> ;put($new_cache);
}
echo "Loading from cache...
";
// Get the cache
$cache = $cl_nav->get();
// Display the cache
foreach($cache as $row){
$id = $row["id"];
$title = $row["title"];
echo "$title
";
}

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php