Magento File Upload via Varien_File_Uploader

MagentoFileUpload.php

<?php
$uploader = new Varien_File_Uploader($_filename);
$uploader->setAllowedExtensions(array('zip','ZIP'));
$uploader->setAllowRenameFiles(true);   //if true, uploaded file's name will be changed, if file with the same name already exists directory. Necessary to avoid conflicts

$uploader->setFilesDispersion(false); //To have a dispersion based on the original file name (as the file option does), we will have to do it manually
$uploader->setAllowCreateFolders(true); //for creating the directory if not exists

$extension = pathinfo(strtolower($_file['name']), PATHINFO_EXTENSION);

$fileName = Mage_Core_Model_File_Uploader::getCorrectFileName($_file['name']);
$dispersion = Mage_Core_Model_File_Uploader::getDispretionPath($fileName);  // We get the dispersion manually here
$fileHash = md5(file_get_contents($_file['tmp_name'])); //here the secretkey

$path = $this->getOrderTargetDir() . $dispersion;
$DestName = $fileHash . '.' . $extension;

$result = $uploader->save($path, $DestName);

?>