Examples of using file caching in PHP

In web development, the pressure on the database can be greatly mitigated by the file cache. 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; } } Copy Code 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 $CL _nav = new Cachelayer ("Navigation"); Check to see if the cache is expired (ten * = minutes) if ($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 "; } Copy Code

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