A php Cache class

A php Cache class

Cache. inc. php: Class Cache { /** * $ Dir: cache file storage directory * $ Lifetime: cache file validity period, in seconds * $ Cacheid: cache file path, including file name * $ Ext: cache file extension (not required), which is used for viewing files conveniently. */ Private $ dir; Private $ lifetime; Private $ cacheid; Private $ ext; /** * Destructor: checks whether the cache directory is valid. the default value is assigned. */ Function _ construct ($ dir = '', $ lifetime = 1800 ){ If ($ this-> dir_isvalid ($ dir )){ $ This-> dir = $ dir; $ This-> lifetime = $ lifetime; $ This-> ext = '. php '; $ This-> cacheid = $ this-> getcacheid (); } } /** * Check whether the cache is valid */ Private function isvalid (){ If (! File_exists ($ this-> cacheid) return false; If (! (@ $ Mtime = filemtime ($ this-> cacheid) return false; If (mktime ()-$ mtime> $ this-> lifetime) return false; Return true; } /** * Write cache * $ Mode = 0. the page content is obtained in browser cache. * $ Mode = 1. the page content is obtained by directly assigning values (received by the $ content parameter ). * $ Mode = 2. obtain the page content locally (fopen ile_get_contents) (it seems that this method is unnecessary) */ Public function write ($ mode = 0, $ content = ''){ Switch ($ mode ){ Case 0: $ Content = ob_get_contents (); Break; Default: Break; } Ob_end_flush (); Try { File_put_contents ($ this-> cacheid, $ content ); } Catch (Exception $ e ){ $ This-> error ('write cache failed! Check the directory permission! '); } } /** * Load cache * Exit () stops the execution of the original page program after loading the cache. if the cache is invalid, run the original page program to generate the cache. * Ob_start () enables browser caching to retrieve page content at the end of the page */ Public function load (){ If ($ this-> isvalid ()){ Echo "This is Cache ."; // Which of the following two methods is better ????? Require_once ($ this-> cacheid ); // Echo file_get_contents ($ this-> cacheid ); Exit (); } Else { Ob_start (); } } /** * Clear cache */ Public function clean (){ Try { Unlink ($ this-> cacheid ); } Catch (Exception $ e ){ $ This-> error ('failed to clear the cached file! Check the directory permission! '); } } /** * Obtain the cache file path */ Private function getcacheid (){ Return $ this-> dir. md5 ($ this-> geturl (). $ this-> ext; } /** * Check whether the directory exists or can be created */ Private function dir_isvalid ($ dir ){ If (is_dir ($ dir) return true; Try { Mkdir ($ dir, 0777 ); } Catch (Exception $ e ){ $ This-> error ('The specified cache directory does not exist and creation failed! Check the directory permission! '); Return false; } Return true; } /** * Obtain the complete url of the current page. */ Private function geturl (){ $ Url = ''; If (isset ($ _ SERVER ['request _ URI ']) { $ Url = $ _ SERVER ['request _ URI ']; } Else { $ Url = $ _ SERVER ['php _ SELF ']; $ Url. = empty ($ _ SERVER ['query _ string'])? '':'? '. $ _ SERVER ['query _ string']; } Return $ url; } /** * Output error message */ Private function error ($ str ){ Echo' '. $ Str .' '; } } ?> Demo. php: /* * You can freely repost and use it. please retain the copyright information. thank you for using it! * Class Name: Cache (For Php5) * Version: 1.0 * Description: a dynamic cache class used to control automatic page cache generation, call cache, update cache, and delete cache. * Author: jiangjun8528@163.com, Junin * Author Page: http://blog.csdn.Net/sdts/ * Last Modify: 2007-8-22 * Remark: 1. this version is Php5. I have not written the Php4 version yet. if you need it, please refer to it for modification. (it's easy. Don't be so lazy !). 2. this version is UTF-8 encoded. if the website uses other encoding, convert it by yourself. in Windows, use notepad to open and save it as a file, and select the corresponding encoding (generally ANSI ), in Linux, use the corresponding editing software or the iconv command line. 3. copy and paste the above 2nd entries. * Some thoughts on cache: * The fundamental difference between dynamic cache and static cache is that it is automatic. when a user accesses a page, the cache is generated, browsed, and updated without manual intervention. * Static cache refers to the generation of static pages. operations are generally completed in the website background and must be manually performed (that is, manually generated ). */ /* * Example ------------------------------------ Demo1 ------------------------------------------- Require_once ('cache. inc. php '); $ Cachedir = './Cache/'; // sets the Cache directory. $ Cache = new Cache ($ cachedir, 10); // if the parameter is omitted, the default setting is used. $ cache = new Cache ($ cachedir ); If ($ _ GET ['cacheac']! = 'Rewrite') // Here is a trick, through xx. Php? Cacheact = rewrite: updates the cache, and so on. you can also set some other operations. $ Cache-> load (); // load the cache. if the cache is valid, the following page code is not executed. // Page code starts Echo date ('H: I: s jS f '); // The page code ends. $ Cache-> write (); // The first time the cache is run or expires, the cache is generated ------------------------------------ Demo2 ------------------------------------------- Require_once ('cache. inc. php '); $ Cachedir = './Cache/'; // sets the Cache directory. $ Cache = new Cache ($ cachedir, 10); // if the parameter is omitted, the default setting is used. $ cache = new Cache ($ cachedir ); If ($ _ GET ['cacheac']! = 'Rewrite') // Here is a trick, through xx. Php? Cacheact = rewrite: updates the cache, and so on. you can also set some other operations. $ Cache-> load (); // load the cache. if the cache is valid, the following page code is not executed. // Page code starts $ Content = date ('H: I: s jS f '); Echo $ content; // The page code ends. $ Cache-> write (1, $ content); // The cache is generated when the first operation or cache expires. ------------------------------------ Demo3 ------------------------------------------- Require_once ('cache. inc. php '); Define ('cacheenable', true ); If (CACHEENABLE ){ $ Cachedir = './Cache/'; // sets the Cache directory. $ Cache = new Cache ($ cachedir, 10); // if the parameter is omitted, the default setting is used. $ cache = new Cache ($ cachedir ); If ($ _ GET ['cacheac']! = 'Rewrite') // Here is a trick, through xx. Php? Cacheact = rewrite: updates the cache, and so on. you can also set some other operations. $ Cache-> load (); // load the cache. if the cache is valid, the following page code is not executed. } // Page code starts $ Content = date ('H: I: s jS f '); Echo $ content; // The page code ends. If (CACHEENABLE) $ Cache-> write (1, $ content); // The cache is generated when the first operation or cache expires. */ ?>

PHP