A simpler NamespaceFile engine for CakePHP 1.2

Using Cake, once you start working with a large number of data cache files, you see the limitation of storing them all in a single directory (which is the default FileEngine behavior). In my case I have a hierarchical Tree behavior on a model and rather than traverse the tree to find its path each time (which incurs a bunch of DB queries), I simply cache the array of its “branch” to save the work. But this means I have a cache file for each node in the tree, and rapidly that gets to be a big number of files in app/tmp.

Frank de Graaf wrote an excellent drop-in upgrade of FileEngine that lets you name the cache keys as namespaces, which get stored in different directories. So you can, for example, delete a group of keys at once by deleting their directory. He doesn’t recommend it for replacing your default FileEngine cache, but for specialized instances (like mine) it works great. One change I did make to his class was to make it extend FileEngine rather than reimplement it like he does – this results in a very compact class that seems to work just as well, as far as I can tell.

To use it, I chose to activate it at runtime, just where I needed it, then switch back to the default. E.g.,

...
	function function_that_needs_this_cache_engine()
	{
		// Use NamespaceFile cache engine, only for this
		App::import('Vendor', 'NamespaceFile'); 
		Cache::config('app', array( 
			'engine' => 'NamespaceFile', 
			'duration'=> '+1 year', 
			'prefix' => 'data.' 
			)); 
 
		Cache::write('namespace.cachename', 'cache_value', "+1 year");
                echo Cache::read('namespace.cachename');
 
		// revert to the normal cache engine
		Cache::config('default', array(
			'engine' => 'File', 
			'path'	=>	ROOT . DS . APP_DIR .  DS . 'tmp'
			));
	}

The class is here; put it in app/vendors/namespace_file.php:

```
<?php 
```
```
/** 
```

 * Partial reimplementation of Cake's original FileEngine. This

 * engine supports namespaces similar to:

```
 * 
```

 * Cache::write('app.pictures.recent', $recentPictures, 'app');

 * Cache::write('app.pictures.top', $topPictures, 'app');

```
 * 
```

 * This namespacing allows deletion of parent namespaces like:

```
 * 
```

 * Cache::delete('app.pictures', 'app');

```
 * 
```

 * The settings for this cache should be

 * defined at the bottom of /config/bootstrap.php like the following:

```
 * 
```

 * App::import('Vendor', 'NamespaceFile');

 * Cache::config('app', array('engine' => 'NamespaceFile', 'duration'=> '+1 hour', 'prefix' => 'cake.'));

```
 * 
```
```
 * Place this file in APP/vendors/. 
```
```
 * 
```

 * WARNING: DO NOT USE AS YOUR APP'S DEFAULT CACHE!

```
 * 
```
```
 * @author Frank de Graaf (Phally) 
```
```
 * @link http://www.frankdegraaf.net 
```
```
 * @license MIT license 
```
```
 * 
```

 * // Modified 9/4/10 by echothis - Changed to extend FileEngine, resulting in a much simpler class

```
 */ 
```

class NamespaceFileEngine extends FileEngine {

```
 
```
```
	/** 
```
```
	 * Write data for key into cache 
```
```
	 * 
```

	 * @param string $key Identifier for the data

	 * @param mixed $data Data to be cached

	 * @param mixed $duration How long to cache the data, in seconds

	 * @return boolean True if the data was succesfully cached, false on failure

```
	 * @access public 
```
```
	 */ 
```

	function write($key, &$data, $duration) {

```
		$writable =& $this->__setKey($key); 
```

		if (!is_a($writable, 'File') || !$this->__init || $data === '') {

```
			return false; 
```
```
		} 
```
```
 
```
```
		if (!$writable->exists()) { 
```

			$writable->Folder->create($this->__getFolderPath($key));

```
			$writable->create(); 
```
```
		} 
```

		parent::write($key, &$data, $duration);

```
	}
```
```
	/** 
```
```
	 * Get absolute file for a given key 
```
```
	 * 
```
```
	 * @param string $key The key 
```

	 * @return mixed Absolute cache file for the given key or false if erroneous

```
	 * @access private 
```
```
	 */ 
```
```
	function __getPath($key) { 
```

		return $this->settings['path'] . str_replace('.', DS, $key);

```
	} 
```
```
 
```
```
	/** 
```

	 * Get absolute folder for a given key

```
	 * 
```
```
	 * @param string $key The key 
```

	 * @return mixed Absolute cache file for the given key or false if erroneous

```
	 * @access private 
```
```
	 */     
```
```
	function __getFolderPath($key) { 
```

		return $this->__getPath(substr($key, 0, strrpos($key, '.') + 1));

```
	} 
```
```
 
```
```
	/** 
```

	 * Return the class (File/Folder) for a key.

```
	 * 
```
```
	 * @param string $key The key 
```

	 * @return mixed File or Folder class for a key.

```
	 * @access private 
```
```
	 */     
```
```
	function __setKey($key) { 
```

		return $this->__setPath($this->__getPath($key));

```
	} 
```
```
 
```
```
	/** 
```

	 * Return the class (File/Folder) for a path.

```
	 * 
```
```
	 * @param string $path The path 
```

	 * @return mixed File or Folder class for a path.

```
	 * @access private 
```
```
	 */         
```
```
	function __setPath($path) { 
```
```
		$this->__File->Folder->cd($path); 
```
```
		if (is_dir($path)) { 
```
```
			$object  = &$this->__File->Folder; 
```
```
			return $object; 
```
```
		} 
```
```
 
```
```
		$this->__File->path = $path; 
```
```
		$object  = &$this->__File; 
```
```
		return $object; 
```
```
	} 
```
```
 
```
```
	/** 
```

	 * Override the parents key method, so the keys don't get transformed

```
	 * 
```
```
	 * @param string $key The key 
```

	 * @return mixed The key if one is passed else return false

```
	 * @access public 
```
```
	 */ 
```
```
	function key($key = null) { 
```
```
		if (empty($key)) { 
```
```
			return false; 
```
```
		} 
```
```
		return $key; 
```
```
	} 
```
```
} 
```
```
?>
```

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