<?php
namespace Sabre\DAV\PartialUpdate;
use Sabre\DAV;
/**
* Partial update plugin (Patch method)
*
* This plugin provides a way to modify only part of a target resource
* It may bu used to update a file chunk, upload big a file into smaller
* chunks or resume an upload.
*
* $patchPlugin = new \Sabre\DAV\PartialUpdate\Plugin();
* $server->addPlugin($patchPlugin);
*
* @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
* @author Jean-Tiare LE BIGOT (http://www.jtlebi.fr/)
* @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
*/
class Plugin extends DAV\ServerPlugin {
/**
* Reference to server
*
* @var Sabre\DAV\Server
*/
protected $server;
/**
* Initializes the plugin
*
* This method is automatically called by the Server class after addPlugin.
*
* @param DAV\Server $server
* @return void
*/
public function initialize(DAV\Server $server) {
$this->server = $server;
$server->subscribeEvent('unknownMethod',array($this,'unknownMethod'));
}
/**
* Returns a plugin name.
*
* Using this name other plugins will be able to access other plugins
* using DAV\Server::getPlugin
*
* @return string
*/
public function getPluginName() {
return 'partialupdate';
}
/**
* This method is called by the Server if the user used an HTTP method
* the server didn't recognize.
*
* This plugin intercepts the PATCH methods.
*
* @param string $method
* @param string $uri
* @return bool|null
*/
public function unknownMethod($method, $uri) {
switch($method) {
case 'PATCH':
return $this->httpPatch($uri);
}
}
/**
* Use this method to tell the server this plugin defines additional
* HTTP methods.
*
* This method is passed a uri. It should only return HTTP methods that are
* available for the specified uri.
*
* We claim to support PATCH method (partial update) if and only if
* - the node exist
* - the node implements our partial update interface
*
* @param string $uri
* @return array
*/
public function getHTTPMethods($uri) {
$tree = $this->server->tree;
if ($tree->nodeExists($uri) &&
$tree->getNodeForPath($uri) instanceof IFile) {
return array('PATCH');
}
return array();
}
/**
* Returns a list of features for the HTTP OPTIONS Dav: header.
*
* @return array
*/
public function getFeatures() {
return array('sabredav-partialupdate');
}
/**
* Patch an uri
*
* The WebDAV patch request can be used to modify only a part of an
* existing resource. If the resource does not exist yet and the first
* offset is not 0, the request fails
*
* @param string $uri
* @return void
*/
protected function httpPatch($uri) {
// Get the node. Will throw a 404 if not found
$node = $this->server->tree->getNodeForPath($uri);
if (!($node instanceof IFile)) {
throw new DAV\Exception\MethodNotAllowed('The target resource does not support the PATCH method.');
}
$range = $this->getHTTPUpdateRange();
if (!$range) {
throw new DAV\Exception\BadRequest('No valid "X-Update-Range" found in the headers');
}
$contentType = strtolower(
$this->server->httpRequest->getHeader('Content-Type')
);
if ($contentType != 'application/x-sabredav-partialupdate') {
throw new DAV\Exception\UnsupportedMediaType('Unknown Content-Type header "' . $contentType . '"');
}
$len = $this->server->httpRequest->getHeader('Content-Length');
// Load the begin and end data
$start = ($range[0])?$range[0]:0;
$end = ($range[1])?$range[1]:$len-1;
// Check consistency
if($end < $start)
throw new DAV\Exception\RequestedRangeNotSatisfiable('The end offset (' . $range[1] . ') is lower than the start offset (' . $range[0] . ')');
if($end - $start + 1 != $len)
throw new DAV\Exception\RequestedRangeNotSatisfiable('Actual data length (' . $len . ') is not consistent with begin (' . $range[0] . ') and end (' . $range[1] . ') offsets');
// Checking If-None-Match and related headers.
if (!$this->server->checkPreconditions()) return;
if (!$this->server->broadcastEvent('beforeWriteContent',array($uri, $node, null)))
return;
$body = $this->server->httpRequest->getBody();
$etag = $node->putRange($body, $start-1);
$this->server->broadcastEvent('afterWriteContent',array($uri, $node));
$this->server->httpResponse->setHeader('Content-Length','0');
if ($etag) $this->server->httpResponse->setHeader('ETag',$etag);
$this->server->httpResponse->sendStatus(204);
return false;
}
/**
* Returns the HTTP custom range update header
*
* This method returns null if there is no well-formed HTTP range request
* header or array($start, $end).
*
* The first number is the offset of the first byte in the range.
* The second number is the offset of the last byte in the range.
*
* If the second offset is null, it should be treated as the offset of the last byte of the entity
* If the first offset is null, the second offset should be used to retrieve the last x bytes of the entity
*
* @return array|null
*/
public function getHTTPUpdateRange() {
$range = $this->server->httpRequest->getHeader('X-Update-Range');
if (is_null($range)) return null;
// Matching "Range: bytes=1234-5678: both numbers are optional
if (!preg_match('/^bytes=([0-9]*)-([0-9]*)$/i',$range,$matches)) return null;
if ($matches[1]==='' && $matches[2]==='') return null;
return array(
$matches[1]!==''?$matches[1]:null,
$matches[2]!==''?$matches[2]:null,
);
}
}
