Marcus Povey <marcus@dushka.co.uk>

* Unfinished filestore code

git-svn-id: https://code.elgg.org/elgg/trunk@494 36083f99-b078-4883-b0ff-0f9b5a30f544

1 files changed, 299 insertions, 0 deletions

diff --git a/engine/lib/filestore.php b/engine/lib/filestore.php
new file mode 100644
index 000000000..3b5dd7543
--- /dev/null
+++ b/engine/lib/filestore.php
@@ -0,0 +1,299 @@
+<?php
+	/**
+	 * Elgg filestore.
+	 * This file contains classes, interfaces and functions for saving and retrieving data to various file 
+	 * stores.
+	 * 
+	 * @package Elgg
+	 * @subpackage API
+	 * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2
+	 * @author Marcus Povey
+	 * @copyright Curverider Ltd 2008
+	 * @link http://elgg.org/
+	 */
+
+	include_once("objects.php");
+	
+	/**
+	 * @class ElggFilestore
+	 * This class defines the interface for all elgg data repositories.
+	 * @author Marcus Povey
+	 */
+	abstract class ElggFilestore
+	{
+		/**
+		 * Attempt to open the file $file for storage or writing.
+		 *
+		 * @param ElggFile $file
+		 * @param string $mode "read", "write", "append"
+		 * @return mixed A handle to the opened file or false on error.
+		 */
+		abstract public function open(ElggFile $file, $mode);
+		
+		/**
+		 * Write data to a given file handle.
+		 *
+		 * @param mixed $f The file handle - exactly what this is depends on the file system
+		 * @param string $data The binary string of data to write
+		 * @return int Number of bytes written.
+		 */
+		abstract public function write($f, $data);
+		
+		/**
+		 * Read data from a filestore.
+		 *
+		 * @param mixed $f The file handle
+		 * @param int $length Length in bytes to read, or 0 for the entire file.
+		 * @param int $offset The optional offset.
+		 * @return mixed String of data or false on error.
+		 */
+		abstract public function read($f, $length = 0, $offset = 0);
+		
+		/**
+		 * Seek a given position within a file handle.
+		 * 
+		 * @param mixed $f The file handle.
+		 * @param int $position The position.
+		 */
+		abstract public function seek($f, $position);
+		
+		/**
+		 * Close a given file handle.
+		 *
+		 * @param mixed $f
+		 */
+		abstract public function close($f);
+		
+		/**
+		 * Delete the file associated with a given file handle.
+		 *
+		 * @param ElggFile $file
+		 */
+		abstract public function delete(ElggFile $file);
+		
+		/**
+		 * Get the filestore's creation parameters as an associative array.
+		 * Used for serialisation and for storing the creation details along side a file object.
+		 * 
+		 * @return array
+		 */
+		abstract public function getParameters();
+		
+		/**
+		 * Set the parameters from the associative array produced by $this->getParameters().
+		 */
+		abstract public function setParameters(array $parameters);
+
+	}
+	
+	/**
+	 * @class ElggDiskFilestore
+	 * This class uses disk storage to save data.
+	 * @author Marcus Povey
+	 */
+	class ElggDiskFilestore extends ElggFilestore
+	{
+		/**
+		 * Directory root.
+		 */
+		private $dir_root;
+		
+		/**
+		 * Default depth of file directory matrix
+		 */
+		private $matrix_depth = 5;
+		
+		/**
+		 * Construct a disk filestore using the given directory root.
+		 *
+		 * @param string $directory_root Root directory, must end in "/"
+		 */
+		public function __construct($directory_root)
+		{
+			$this->dir_root = $directory_root;
+		}
+		
+		public function open(ElggFile $file, $mode)
+		{
+			// Try and create the directory
+			try { $this->make_directory_root($this->dir_root); } catch (Exception $e){}
+			
+			$name = $file->getFilename();
+			$matrix = $this->make_file_matrix($name);
+			
+			switch ($mode)
+			{
+				case "read" : $mode = "r+b"; break;
+				case "write" : $mode = "w+b"; break;
+				case "append" : $mode = "a+b"; break;
+				default: throw new InvalidParameterException("Unrecognised file mode '$mode'");
+			}
+			
+			return fopen($this->dir_root . $matrix . $name, $mode);
+		}
+		
+		public function write($f, $data)
+		{
+			return fwrite($f, $data);
+		}
+		
+		public function read($f, $length = 0, $offset = 0)
+		{
+			if ($offset)
+				$this->seek($f, $offset);
+				
+			return fread($f, $length);
+		}
+		
+		public function close($f)
+		{
+			return fclose($f);
+		}
+		
+		public function delete(ElggFile $file)
+		{
+			$name = $file->getFilename();
+			$matrix = $this->make_file_matrix($name);
+			
+			$unlink = unlink($this->dir_root . $matrix . $name);
+			if ($unlink)
+				return $file->delete();
+	
+			return false;
+		}
+		
+		public function seek($f, $position)
+		{
+			return fseek($f, $position);
+		}
+		
+		/**
+		 * Make the directory root.
+		 *
+		 * @param string $dirroot
+		 */
+		protected function make_directory_root($dirroot)
+		{
+			if (!mkdir($dir, 0700, true)) 
+				throw new IOException("Could not make $dirroot");
+				
+			return true;
+		}
+		
+		/**
+		 * Construct the filename matrix.
+		 *
+		 * @param string $filename
+		 */
+		protected function make_file_matrix($filename)
+		{
+			$matrix = "";
+			
+			$len = strlen($ident);
+			if ($len>$this->matrix_depth)
+				$len = $this->matrix_depth;
+			
+			for ($n = 0; $n < strlen($ident); $n++)
+				$matrix .= $ident[$n] . "/";	
+	
+			return $matrix;
+		}
+		
+		public function getParameters()
+		{
+			return array("dir_root" => $this->dir_root);
+		}
+		
+		public function setParameters(array $parameters)
+		{
+			if (isset($parameters['dir_root']))
+			{
+				$this->dir_root = $parameters['dir_root'];
+				return true;
+			}
+			
+			return false;
+		}
+	}
+	
+	/**
+	 * @class ElggFile
+	 * This class represents a physical file.
+	 * @author Marcus Povey
+	 */
+	class ElggFile extends ElggObject
+	{
+		protected function initialise_attributes()
+		{
+			parent::initialise_attributes();
+			
+			$this->attributes['subtype'] = "file";
+		}
+		
+		function __construct($guid = null) 
+		{			
+			parent::__construct($guid);
+			
+		}
+		
+		// TODO: Save filestore & filestore parameters - getparameters, save them as name/value with type "$datastoreclassname"
+
+		// TODO: Set name and optional description
+		
+		
+		//get datastore (save with object as meta/ load from create)
+		
+		// constrcut
+
+		// initialise (set subtype to elggfile)
+
+		// set name
+	
+		
+		
+		// read / write / open / close / delete
+
+		// Get name
+
+
+		
+		// getFilestore
+			
+			
+			// if $filestore is blank, try and get from meta
+			// if meta not found or guid is null then get from default
+		
+	}
+	
+
+	/// Variable holding the default datastore
+	$DEFAULT_FILE_STORE = NULL;
+	
+	/**
+	 * Return the default filestore.
+	 *
+	 * @return ElggFilestore
+	 */
+	function get_default_filestore()
+	{
+		global $DEFAULT_FILE_STORE;
+		
+		return $DEFAULT_FILE_STORE;
+	}
+	
+	/**
+	 * Set the default filestore for the system.
+	 */
+	function set_default_filestore(ElggFilestore $filestore)
+	{
+		global $DEFAULT_FILE_STORE;
+		
+		$DEFAULT_FILE_STORE = $filestore;
+		
+		return true;
+	}
+	
+	
+	// Now register a default filestore
+	set_default_filestore(new ElggDiskFilestore($CONFIG->dataroot));
+?>
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