Kao

Simple to use and lightweight PHP caching class.

Requirements

PHP 5.6 or newer

Install

1. The whole class is one file, so just download it and add line this to the beginning of your PHP file:

   require "PATH/TO/kao.class.php";

2. Create subfolder cache in folder where you downloaded kao.class.php.

3. Change configuration if necessary.

Configuration

You can adjust the configuration if you need to. It's directly implemenented at the beginning of kao.class.php (around line 16). Currently there are these settings:

• dirCache: directory where cache will be stored (if it doesn't exist, Kao will try to create it)
  • default: __DIR__ . "/cache"
• id_hashAlgo: hashing algorithm used to hash identifier
  • default: "md5"
  • values: any hashing algorithm supported by your version of PHP, e.g.: md5, sha256,...
• returnPathType: type of path (relative or absolute) used in return values of functions
  • default: "absolute"
  • values: relative, absolute
• dirCreatePermissions: directory permissions to use when creating new folders (in octal)
  • default: 0750

Usage

The way this class works is: create cache and save it -> read saved cache when is needed -> remove old cache.

Best practice of this is reading cache where you need it, but creating (and also removing old one) using another file called by CRON job (in certain interval).

Supported data types

• www: Stores and reads/returns website source as string.

• www_json: For websites with JSON content. JSON is downloaded from website, stored, and converted to PHP array when you want to read() it.

• string: Stores and reads/returns direct string input.

• array: Stores direct array input (as JSON and converts it back on read()).

• json: Stores direct JSON input, reads/returns it as array/string.

Example

• source of https://jsonplaceholder.typicode.com/comments/1/:

  {
     "postId": 1,
     "id": 1,
     "name": "id labore ex et quam laborum",
     "email": "Eliseo@gardner.biz",
     "body": "laudantium ... accusantium"
  }

• cron.php:

  $kao = new Kao("latestComment", "www_json");
  $kao->create("https://jsonplaceholder.typicode.com/comments/1/");
  $kao->remove_old(600);

• index.php:

  $kao = new Kao("latestComment", "www_json");
  $content = $kao->read();
  print_r($content);
  
  // RESULT:
  // Array (
  //    [postId] => 1
  //    [id] => 1
  //    [name] => id labore ex et quam laborum
  //    [email] => Eliseo@gardner.biz
  //    [body] => laudantium ... accusantium
  // )

Functions

Construct

Parameters:

• string $id: identifier
• string $dataType: one of supported data types

Return: void

Syntax:

$kao = new Kao($id, $dataType);

---

create()

Creates cache files

Parameters:

• string|array $input: www address or direct input
• [array $filter: e.g.: [0, "a"] will do $input[0]["a"] (applies only for www_json, array or json dataType)]

Return: (string) path of created cache file

Syntax:

$kao->create($input [, $filter]);

---

read()

Reads cache files

Parameters: no parameters

Return: (string|array) latest available cache (according to dataType)

Syntax:

$kao->read();

---

remove_old()

Removes old cache

I strongly recommend to always have at least two versions of cache (new and one older), to eliminate situations like: you have a huge file cached and in the middle of loading it by one of your PHP scripts you delete that cache file and your website will display an error. So simple math: best $age is 2 - 3 times interval of creating new cache files, e.g. if you run create() function every 5 minutes, correct value is 600 seconds (10 minutes) or more.

Parameters:

• int $age: min. age of files to remove (in seconds)

Return: (array) list of removed files

Syntax:

$kao->remove_old($age);

---

delete()

Deletes everything by id - all cache files and file with data

Parameters: no parameters

Return: (array) list of deleted files

Syntax:

$kao->delete();

---

latest_cache_info()

Returns informations about latest cache file (in current id).

Parameters: no parameters

Return: (array) info:

array (
   "file" => (filename),
   "path" => (relative path to the file, to get absolute just add dirCache + "/files/" to the beginning of this),
   "dataType" => (dataType),
   "extension" => (file extension),
   "timestamp" => (UNIX timestamp of cache file creation)
)

Syntax:

$kao->latest_cache_info();

Credits

Kao was created by Dávid Benko. Released under MIT license.