Webdav/src/backends/memory.php - zetacomponents - Git at Google

 <?php
 /**
  * File containing the ezcWebdavMemoryBackend class.
  *
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  *
  * @package Webdav
  * @version //autogentag//
  * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
  * @access private
  */
 /**
  * Backend that only resides in memory.
  *
  * Memory backend to serve some virtual content tree, offering options to cause
  * failures in operations, mainly for testing the webdav server.
  *
  * The content of the backend is constructed from a multidimentional array
  * structure representing the collections and files. The metadata may only be
  * set by appropriate requests to the backend. No information is stored
  * anywhere, so that every reinitialisations gives you a fresh backend.
  *
  * <code>
  *  $backend = new ezcWebdavMemoryBackend();
  *  $backend->addContents(
  *      array(
  *          'foo' => 'bar', // File with content "bar"
  *          'bar' => array( // Collection "bar"
  *              'blubb' => 'Some more content.'
  *                  // File bar/blubb with some more content
  *          ),
  *      )
  *  );
  * </code>
  *
  * This backend does not implement any special features to test the servers
  * capabilities to work with those features.
  *
  * @version //autogentag//
  * @package Webdav
  * @access private
  */
 class ezcWebdavMemoryBackend extends ezcWebdavSimpleBackend implements ezcWebdavLockBackend
 {
     /**
      * Options of the memory backend
      *
      * @var ezcWebdavMemoryBackendOptions
      */
     protected $options;

     /**
      * Content structure of memory backend
      *
      * @var array
      */
     protected $content = array(
         '/' => array(),
     );

     /**
      * Properties for collections and resources.
      *
      * They are stored in an array of the following form reusing the initial
      * content example:
      *
      *  array(
      *      '/foo' => array(
      *          'property name' => 'property value',
      *      ),
      *      '/bar' => array(),
      *      '/bar/blubb' => array(),
      *      ...
      *  )
      *
      * @var array
      */
     protected $props = array();

     /**
      * Indicates wheather to fake live properties.
      *
      * @var bool
      */
     protected $fakeLiveProperties;

     /**
      * Construct backend from a given path.
      *
      * @param bool $fakeLiveProperties
      * @return void
      */
     public function __construct( $fakeLiveProperties = true )
     {
         $this->options = new ezcWebdavMemoryBackendOptions();

         $this->fakeLiveProperties = $fakeLiveProperties;

         // Initialize properties for root
         if ( $fakeLiveProperties )
         {
             $this->props['/'] = $this->initializeProperties( '/', true );
         }
     }

     /**
      * Acquire a backend lock.
      *
      * Locks the complete backend using the lock file specified in {@link
      * ezcWebdavMemoryBackendOptions->$lockFile}.
      *
      * @param int $waitTime Microseconds.
      * @param int $timeout Microseconds.
      * @return void
      */
     public function lock( $waitTime, $timeout )
     {
         $lockFile = $this->options->lockFile;

         $lockStart = microtime( true );

         // fopen in mode 'x' will only open the file, if it does not exist yet.
         // Even this is is expected it will throw a warning, if the file
         // exists, which we need to silence using the @
         while ( ( $fp = @fopen( $lockFile, 'x' ) ) === false )
         {
             // This is untestable.
             if ( microtime( true ) - $lockStart > $timeout )
             {
                 // Release timed out lock
                 unlink( $lockFile );
                 $lockStart = microtime( true );
             }
             else
             {
                 usleep( $waitTime );
             }
         }

         // Store random bit in file ... the microtime for example - might prove
         // useful some time.
         fwrite( $fp, microtime() );
         fclose( $fp );
     }

     /**
      * Release the backend lock.
      *
      * Releases the lock acquired by {@link lock()}.
      *
      * @return void
      */
     public function unlock()
     {
         // Silence since lock maybe released if request processing takes too
         // long
         @unlink( $this->options->lockFile );
     }

     /**
      * Offer access to some of the server properties.
      *
      * @throws ezcBasePropertyNotFoundException
      *         If the property $name is not defined
      * @param string $name
      * @return mixed
      * @ignore
      */
     public function __get( $name )
     {
         switch ( $name )
         {
             case 'options':
                 return $this->$name;

             default:
                 throw new ezcBasePropertyNotFoundException( $name );
         }
     }

     /**
      * Sets the option $name to $value.
      *
      * @throws ezcBasePropertyNotFoundException
      *         if the property $name is not defined
      * @throws ezcBaseValueException
      *         if $value is not correct for the property $name
      * @param string $name
      * @param mixed $value
      * @return void
      * @ignore
      */
     public function __set( $name, $value )
     {
         switch ( $name )
         {
             case 'options':
                 if ( ! $value instanceof ezcWebdavMemoryBackendOptions )
                 {
                     throw new ezcBaseValueException( $name, $value, 'ezcWebdavMemoryBackendOptions' );
                 }

                 $this->$name = $value;
                 break;

             default:
                 throw new ezcBasePropertyNotFoundException( $name );
         }
     }

     /**
      * Return an initial set of properties for resources and collections.
      *
      * The second parameter indicates wheather the given resource is a
      * collection. The returned properties are used to initialize the property
      * arrays for the given content.
      *
      * @param string $name
      * @param bool $isCollection
      * @return array
      *
      * @access protected
      */
     public function initializeProperties( $name, $isCollection = false )
     {
         if ( $this->fakeLiveProperties )
         {
             $propertyStorage = new ezcWebdavBasicPropertyStorage();

             // Add default creation date
             $propertyStorage->attach(
                 new ezcWebdavCreationDateProperty( new ezcWebdavDateTime( '@1054034820' ) )
             );

             // Define default display name
             $propertyStorage->attach(
                 new ezcWebdavDisplayNameProperty( basename( urldecode( $name ) ) )
             );

             // Define default language
             $propertyStorage->attach(
                 new ezcWebdavGetContentLanguageProperty( array( 'en' ) )
             );

             // Define default content type
             $propertyStorage->attach(
                 new ezcWebdavGetContentTypeProperty(
                     $isCollection ? 'httpd/unix-directory' : 'application/octet-stream'
                 )
             );

             // Define default ETag
             $propertyStorage->attach(
                 new ezcWebdavGetEtagProperty( $this->getETag( $name ) )
             );

             // Define default modification time
             $propertyStorage->attach(
                 new ezcWebdavGetLastModifiedProperty( new ezcWebdavDateTime( '@1124118780' ) )
             );

             // Define content length if node is a resource.
             $propertyStorage->attach(
                 new ezcWebdavGetContentLengthProperty(
                     $isCollection ?
                         ezcWebdavGetContentLengthProperty::COLLECTION :
                         (string) strlen( $this->content[$name] )
                 )
             );

             $propertyStorage->attach(
                 new ezcWebdavResourceTypeProperty(
                     ( $isCollection === true ?
                         ezcWebdavResourceTypeProperty::TYPE_COLLECTION :
                         ezcWebdavResourceTypeProperty::TYPE_RESOURCE
                     )
                 )
             );
         }
         else
         {
             $propertyStorage = new ezcWebdavBasicPropertyStorage();
         }

         return $propertyStorage;
     }

     /**
      * Clones the given $fromStorage for $toPath.
      *
      * Initializes a new property storage for $toPath with new live properties
      * and clones all non exsitent properties from $fromStorage to it.
      *
      * @param string $toPath
      * @param bool $isCollection
      * @param ezcWebdavBasicPropertyStorage $fromStorage
      * @return void
      */
     private function cloneProperties( $toPath, $isCollection, ezcWebdavBasicPropertyStorage $fromStorage )
     {
         $toStorage = $this->initializeProperties( $toPath, $isCollection );

         foreach ( $fromStorage as $prop )
         {
             if ( !$toStorage->contains( $prop->name, $prop->namespace ) )
             {
                 $toStorage->attach( clone $prop );
             }
         }
         $this->props[$toPath] = $toStorage;
     }

     /**
      * Overwrites ETag generation from simple backend.
      *
      * Generates an ETag based on $path and the content of $path (if available
      * and not a collection).
      *
      * @param string $path
      * @return string
      */
     protected function getETag( $path )
     {
         return ( md5( $path ) );
     }

     /**
      * Read valid data from given content array and initialize property
      * storage.
      *
      * @param array $contents
      * @param string $path
      * @return void
      */
     public function addContents( array $contents, $path = '/' )
     {
         foreach ( $contents as $name => $content )
         {
             if ( !is_string( $name ) )
             {
                 // Ignore elements which do not have a string key
                 continue;
             }

             // Full path to resource
             $resourcePath = $path . $name;

             if ( is_array( $content ) )
             {
                 // Content is a collection
                 $this->content[$resourcePath] = array();
                 $this->props[$resourcePath] = $this->initializeProperties(
                     $resourcePath,
                     true
                 );

                 // Recurse
                 $this->addContents( $content, $resourcePath . '/' );
             }
             elseif ( is_string( $content ) )
             {
                 // Content is a file
                 $this->content[$resourcePath] = $content;
                 $this->props[$resourcePath] = $this->initializeProperties(
                     $resourcePath
                 );
             }
             else
             {
                 // Ignore everything else...
                 continue;
             }

             // Add contents to parent directory
             $parent = ( $path === '/' ? '/' : substr( $path, 0, -1 ) );
             $this->content[$parent][] = $resourcePath;
         }
     }

     /**
      * Create a new collection.
      *
      * Creates a new collection at the given path.
      *
      * @param string $path
      * @return void
      */
     protected function createCollection( $path )
     {
         // Create collection
         $this->content[$path] = array();

         // Add collection to parent node
         $this->content[dirname( $path )][] = $path;

         // Set initial metadata for collection
         $this->props[$path] = $this->initializeProperties( $path, true );
     }

     /**
      * Create a new resource.
      *
      * Creates a new resource at the given path, optionally with the given
      * content.
      *
      * @param string $path
      * @param string $content
      * @return void
      */
     protected function createResource( $path, $content = null )
     {
         // Create resource
         $this->content[$path] = $content;

         // Add resource to parent node
         $this->content[dirname( $path )][] = $path;

         // Set initial metadata for collection
         $this->props[$path] = $this->initializeProperties( $path, false );
     }

     /**
      * Set contents of a resource.
      *
      * Change the contents of the given resource to the given content.
      *
      * @param string $path
      * @param string $content
      * @return void
      */
     protected function setResourceContents( $path, $content )
     {
         $this->content[$path] = $content;
     }

     /**
      * Get contents of a resource.
      *
      * @param string $path
      * @return string
      */
     protected function getResourceContents( $path )
     {
         return $this->content[$path];
     }

     /**
      * Manually set a property on a resource to request it later.
      *
      * @param string $resource
      * @param ezcWebdavProperty $property
      * @return bool
      */
     public function setProperty( $resource, ezcWebdavProperty $property )
     {
         // Live properties may not be updated by a client.
         if ( $this->options->failingOperations & ezcWebdavMemoryBackendOptions::REQUEST_PROPPATCH )
         {
             return false;
         }

         // Bail out, if the resource is not known yet.
         if ( !array_key_exists( $resource, $this->props ) )
         {
             return false;
         }

         $this->props[$resource]->attach( $property );
         return true;
     }

     /**
      * Manually remove a property from a resource.
      *
      * @param string $resource
      * @param ezcWebdavProperty $property
      * @return bool
      */
     public function removeProperty( $resource, ezcWebdavProperty $property )
     {
         // Live properties may not be removed.
         if ( $property instanceof ezcWebdavLiveProperty )
         {
             return false;
         }

         $this->props[$resource]->detach( $property->name, $property->namespace );
         return true;
     }

     /**
      * Reset property storage for a resource.
      *
      * @param string $resource
      * @param ezcWebdavPropertyStorage $properties
      * @return bool
      */
     public function resetProperties( $resource, ezcWebdavPropertyStorage $properties )
     {
         $this->props[$resource] = $properties;
     }

     /**
      * Manually get a property on a resource.
      *
      * Get the property with the given name from the given resource. You may
      * optionally define a namespace to receive the property from.
      *
      * @param string $resource
      * @param string $propertyName
      * @param string $namespace
      * @return ezcWebdavProperty
      */
     public function getProperty( $resource, $propertyName, $namespace = 'DAV:' )
     {
         return $this->props[$resource]->get( $propertyName, $namespace );
     }

     /**
      * Manually get a property on a resource.
      *
      * Get all properties for the given resource as a {@link
      * ezcWebdavPropertyStorage}
      *
      * @param string $resource
      * @return ezcWebdavBasicPropertyStorage
      */
     public function getAllProperties( $resource )
     {
         return $this->props[$resource];
     }

     /**
      * Copy resources recursively from one path to another.
      *
      * Returns an array with {@link ezcWebdavErrorResponse}s for all subtree,
      * where the copy operation failed. Errors subsequent nodes in a subtree
      * should be ommitted.
      *
      * If an empty array is return, the operation has been completed
      * successfully.
      *
      * @param string $fromPath
      * @param string $toPath
      * @param int $depth
      * @return array(ezcWebdavErrorResponse)
      */
     protected function performCopy( $fromPath, $toPath, $depth = ezcWebdavRequest::DEPTH_INFINITY )
     {
         $causeErrors = (bool) ( $this->options->failingOperations & ( ezcWebdavMemoryBackendOptions::REQUEST_COPY | ezcWebdavMemoryBackendOptions::REQUEST_MOVE ) );
         $errors = array();

         if ( !is_array( $this->content[$fromPath] ) ||
              ( is_array( $this->content[$fromPath] ) && ( $depth === ezcWebdavRequest::DEPTH_ZERO ) ) )
         {
             // Copy a resource, or a collection, but the depth header told not
             // to recurse into collections
             if ( $causeErrors && preg_match( $this->options->failForRegexp, $fromPath ) > 0 )
             {
                 // Completely abort with error
                 return array( ezcWebdavErrorResponse(
                     ezcWebdavResponse::STATUS_423,
                     $fromPath
                 ) );
             }
             if ( $causeErrors && preg_match( $this->options->failForRegexp, $toPath ) > 0 )
             {
                 // Completely abort with error
                 return array( ezcWebdavErrorResponse(
                     ezcWebdavResponse::STATUS_412,
                     $toPath
                 ) );
             }

             // Perform copy operation
             if ( is_array( $this->content[$fromPath] ) )
             {
                 // Create a new empty collection
                 $this->content[$toPath] = array();
             }
             else
             {
                 // Copy file content
                 $this->content[$toPath] = $this->content[$fromPath];
             }

             // Copy properties
             $this->cloneProperties(
                 $toPath,
                 is_array( $this->content[$toPath] ),
                 $this->props[$fromPath]
             );

             // Add to parent node
             $this->content[dirname( $toPath )][] = $toPath;
         }
         else
         {
             // Copy a collection
             $errnousSubtrees = array();

             // Array of copied collections, where the child names are required
             // to be modified depending on the success of the copy operation.
             $copiedCollections = array();

             // Check all nodes, if they math the fromPath
             foreach ( $this->content as $resource => $content )
             {
                 if ( strpos( $resource, $fromPath ) !== 0 )
                 {
                     // This resource is not affected by the copy operation
                     continue;
                 }

                 // Check if this resource should be skipped, because
                 // already one of the parent nodes caused an error.
                 foreach ( $errnousSubtrees as $subtree )
                 {
                     if ( strpos( $resource, $subtree ) )
                     {
                         // Skip resource, then.
                         continue 2;
                     }
                 }

                 // Check if this resource should cause an error
                 if ( $causeErrors && preg_match( $this->options->failForRegexp, $resource ) )
                 {
                     // Cause an error and skip resource
                     $errors[] = new ezcWebdavErrorResponse(
                         ezcWebdavResponse::STATUS_423,
                         $resource
                     );
                     continue;
                 }

                 // To actually perform the copy operation, modify the
                 // destination resource name
                 $newResourceName = preg_replace( '(^' . preg_quote( $fromPath ) . ')', $toPath, $resource );

                 // Check if this resource should cause an error
                 if ( $causeErrors && preg_match( $this->options->failForRegexp, $newResourceName ) )
                 {
                     // Cause an error and skip resource
                     $errors[] = new ezcWebdavErrorResponse(
                         ezcWebdavResponse::STATUS_412,
                         $newResourceName
                     );
                     continue;
                 }

                 // Add collection to collection child recalculation array
                 if ( is_array( $this->content[$resource] ) )
                 {
                     $copiedCollections[] = $newResourceName;
                 }

                 // Actually copy
                 $this->content[$newResourceName] = $this->content[$resource];

                 // Copy properties
                 $this->cloneProperties(
                     $newResourceName,
                     is_array( $this->content[$resource] ),
                     $this->props[$resource]
                 );

                 // Add to parent node
                 $this->content[dirname( $newResourceName )][] = $newResourceName;
             }

             // Iterate over all copied collections and update the child
             // references
             foreach ( $copiedCollections as $collection )
             {
                 foreach ( $this->content[$collection] as $nr => $child )
                 {
                     foreach ( $errnousSubtrees as $subtree )
                     {
                         if ( strpos( $child, $subtree ) )
                         {
                             // If child caused an error, it has not been
                             // copied, so we remove it.
                             unset( $this->content[$collection][$nr] );
                             continue 2;
                         }
                     }

                     // Also remove all references to old children, new children
                     // have already been added during the last step.
                     if ( preg_match( '(^' . preg_quote( $fromPath ) . ')', $child ) )
                     {
                         unset( $this->content[$collection][$nr] );
                     }
                 }

                 $this->content[$collection] = array_values( $this->content[$collection] );
             }
         }

         return $errors;
     }

     /**
      * Delete everything below this path.
      *
      * Returns an error response if the deletion failed, and null on success.
      *
      * @param string $path
      * @return ezcWebdavErrorResponse
      */
     protected function performDelete( $path )
     {
         // Check if any errors would occur during deletion process
         $error = array();
         foreach ( $this->content as $name => $content )
         {
             if ( strpos( $name, $path ) === 0 && ( substr( $name, strlen( $path ), 1 ) === '/' || $name === $path ) )
             {
                 // Check if we want to cause some errors here.
                 if ( $this->options->failingOperations & ezcWebdavMemoryBackendOptions::REQUEST_DELETE && preg_match( $this->options->failForRegexp, $name ) > 0 )
                 {
                     $error[] = new ezcWebdavErrorResponse(
                         ezcWebdavResponse::STATUS_423,
                         $name
                     );
                 }
             }
         }

         // If errors occured, return them
         if ( count( $error ) )
         {
             return new ezcWebdavMultistatusResponse(
                 $error
             );
         }

         // Remove all content nodes starting with requested path
         foreach ( $this->content as $name => $content )
         {
             if ( strpos( $name, $path ) === 0 && ( substr( $name, strlen( $path ), 1 ) === '/' || $name === $path ) )
             {
                 unset( $this->content[$name] );
                 unset( $this->props[$name] );
             }
         }

         // Remove parent node assignement to removed node
         $id = array_search( $path, $this->content[$parent = dirname( $path )] );
         if ( $id !== false )
         {
             unset( $this->content[$parent][$id] );
             $this->content[$parent] = array_values( $this->content[$parent] );
         }

         return null;
     }

     /**
      * Check if node exists.
      *
      * Check if a node exists with the given path.
      *
      * @param string $path
      * @return bool
      *
      * @access protected
      */
     public function nodeExists( $path )
     {
         return isset( $this->content[$path] );
     }

     /**
      * Check if node is a collection.
      *
      * Check if the node behind the given path is a collection.
      *
      * @param string $path
      * @return bool
      *
      * @access protected
      */
     public function isCollection( $path )
     {
         return $this->nodeExists( $path ) && is_array( $this->content[$path] );
     }

     /**
      * Get members of collection.
      *
      * Returns an array with the members of the collection given by the path of
      * the collection.
      *
      * The returned array holds elements which are either ezcWebdavCollection,
      * or ezcWebdavResource.
      *
      * @param string $path
      * @return array
      */
     protected function getCollectionMembers( $path )
     {
         $contents = array();

         foreach ( $this->content[$path] as $child )
         {
             if ( is_array( $this->content[$child] ) )
             {
                 // Add collection without any children
                 $contents[] = new ezcWebdavCollection(
                     $child
                 );
             }
             else
             {
                 // Add files without content
                 $contents[] = new ezcWebdavResource(
                     $child
                 );
             }
         }

         return $contents;
     }

     /**
      * Clones the memory backend deeply.
      *
      * @return void
      */
     public function __clone()
     {
         foreach ( $this->props as $path => $propStorage )
         {
             $this->props[$path] = clone $propStorage;
         }
     }
 }

 ?>
	<?php
	/**
	* File containing the ezcWebdavMemoryBackend class.
	*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*
	* @package Webdav
	* @version //autogentag//
	* @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
	* @access private
	*/
	/**
	* Backend that only resides in memory.
	*
	* Memory backend to serve some virtual content tree, offering options to cause
	* failures in operations, mainly for testing the webdav server.
	*
	* The content of the backend is constructed from a multidimentional array
	* structure representing the collections and files. The metadata may only be
	* set by appropriate requests to the backend. No information is stored
	* anywhere, so that every reinitialisations gives you a fresh backend.
	*
	* <code>
	* $backend = new ezcWebdavMemoryBackend();
	* $backend->addContents(
	* array(
	* 'foo' => 'bar', // File with content "bar"
	* 'bar' => array( // Collection "bar"
	* 'blubb' => 'Some more content.'
	* // File bar/blubb with some more content
	* ),
	* )
	* );
	* </code>
	*
	* This backend does not implement any special features to test the servers
	* capabilities to work with those features.
	*
	* @version //autogentag//
	* @package Webdav
	* @access private
	*/
	class ezcWebdavMemoryBackend extends ezcWebdavSimpleBackend implements ezcWebdavLockBackend
	{
	/**
	* Options of the memory backend
	*
	* @var ezcWebdavMemoryBackendOptions
	*/
	protected $options;

	/**
	* Content structure of memory backend
	*
	* @var array
	*/
	protected $content = array(
	'/' => array(),
	);

	/**
	* Properties for collections and resources.
	*
	* They are stored in an array of the following form reusing the initial
	* content example:
	*
	* array(
	* '/foo' => array(
	* 'property name' => 'property value',
	* ),
	* '/bar' => array(),
	* '/bar/blubb' => array(),
	* ...
	* )
	*
	* @var array
	*/
	protected $props = array();

	/**
	* Indicates wheather to fake live properties.
	*
	* @var bool
	*/
	protected $fakeLiveProperties;

	/**
	* Construct backend from a given path.
	*
	* @param bool $fakeLiveProperties
	* @return void
	*/
	public function __construct( $fakeLiveProperties = true )
	{
	$this->options = new ezcWebdavMemoryBackendOptions();

	$this->fakeLiveProperties = $fakeLiveProperties;

	// Initialize properties for root
	if ( $fakeLiveProperties )
	{
	$this->props['/'] = $this->initializeProperties( '/', true );
	}
	}

	/**
	* Acquire a backend lock.
	*
	* Locks the complete backend using the lock file specified in {@link
	* ezcWebdavMemoryBackendOptions->$lockFile}.
	*
	* @param int $waitTime Microseconds.
	* @param int $timeout Microseconds.
	* @return void
	*/
	public function lock( $waitTime, $timeout )
	{
	$lockFile = $this->options->lockFile;

	$lockStart = microtime( true );

	// fopen in mode 'x' will only open the file, if it does not exist yet.
	// Even this is is expected it will throw a warning, if the file
	// exists, which we need to silence using the @
	while ( ( $fp = @fopen( $lockFile, 'x' ) ) === false )
	{
	// This is untestable.
	if ( microtime( true ) - $lockStart > $timeout )
	{
	// Release timed out lock
	unlink( $lockFile );
	$lockStart = microtime( true );
	}
	else
	{
	usleep( $waitTime );
	}
	}

	// Store random bit in file ... the microtime for example - might prove
	// useful some time.
	fwrite( $fp, microtime() );
	fclose( $fp );
	}

	/**
	* Release the backend lock.
	*
	* Releases the lock acquired by {@link lock()}.
	*
	* @return void
	*/
	public function unlock()
	{
	// Silence since lock maybe released if request processing takes too
	// long
	@unlink( $this->options->lockFile );
	}

	/**
	* Offer access to some of the server properties.
	*
	* @throws ezcBasePropertyNotFoundException
	* If the property $name is not defined
	* @param string $name
	* @return mixed
	* @ignore
	*/
	public function __get( $name )
	{
	switch ( $name )
	{
	case 'options':
	return $this->$name;

	default:
	throw new ezcBasePropertyNotFoundException( $name );
	}
	}

	/**
	* Sets the option $name to $value.
	*
	* @throws ezcBasePropertyNotFoundException
	* if the property $name is not defined
	* @throws ezcBaseValueException
	* if $value is not correct for the property $name
	* @param string $name
	* @param mixed $value
	* @return void
	* @ignore
	*/
	public function __set( $name, $value )
	{
	switch ( $name )
	{
	case 'options':
	if ( ! $value instanceof ezcWebdavMemoryBackendOptions )
	{
	throw new ezcBaseValueException( $name, $value, 'ezcWebdavMemoryBackendOptions' );
	}

	$this->$name = $value;
	break;

	default:
	throw new ezcBasePropertyNotFoundException( $name );
	}
	}

	/**
	* Return an initial set of properties for resources and collections.
	*
	* The second parameter indicates wheather the given resource is a
	* collection. The returned properties are used to initialize the property
	* arrays for the given content.
	*
	* @param string $name
	* @param bool $isCollection
	* @return array
	*
	* @access protected
	*/
	public function initializeProperties( $name, $isCollection = false )
	{
	if ( $this->fakeLiveProperties )
	{
	$propertyStorage = new ezcWebdavBasicPropertyStorage();

	// Add default creation date
	$propertyStorage->attach(
	new ezcWebdavCreationDateProperty( new ezcWebdavDateTime( '@1054034820' ) )
	);

	// Define default display name
	$propertyStorage->attach(
	new ezcWebdavDisplayNameProperty( basename( urldecode( $name ) ) )
	);

	// Define default language
	$propertyStorage->attach(
	new ezcWebdavGetContentLanguageProperty( array( 'en' ) )
	);

	// Define default content type
	$propertyStorage->attach(
	new ezcWebdavGetContentTypeProperty(
	$isCollection ? 'httpd/unix-directory' : 'application/octet-stream'
	)
	);

	// Define default ETag
	$propertyStorage->attach(
	new ezcWebdavGetEtagProperty( $this->getETag( $name ) )
	);

	// Define default modification time
	$propertyStorage->attach(
	new ezcWebdavGetLastModifiedProperty( new ezcWebdavDateTime( '@1124118780' ) )
	);

	// Define content length if node is a resource.
	$propertyStorage->attach(
	new ezcWebdavGetContentLengthProperty(
	$isCollection ?
	ezcWebdavGetContentLengthProperty::COLLECTION :
	(string) strlen( $this->content[$name] )
	)
	);

	$propertyStorage->attach(
	new ezcWebdavResourceTypeProperty(
	( $isCollection === true ?
	ezcWebdavResourceTypeProperty::TYPE_COLLECTION :
	ezcWebdavResourceTypeProperty::TYPE_RESOURCE
	)
	)
	);
	}
	else
	{
	$propertyStorage = new ezcWebdavBasicPropertyStorage();
	}

	return $propertyStorage;
	}

	/**
	* Clones the given $fromStorage for $toPath.
	*
	* Initializes a new property storage for $toPath with new live properties
	* and clones all non exsitent properties from $fromStorage to it.
	*
	* @param string $toPath
	* @param bool $isCollection
	* @param ezcWebdavBasicPropertyStorage $fromStorage
	* @return void
	*/
	private function cloneProperties( $toPath, $isCollection, ezcWebdavBasicPropertyStorage $fromStorage )
	{
	$toStorage = $this->initializeProperties( $toPath, $isCollection );

	foreach ( $fromStorage as $prop )
	{
	if ( !$toStorage->contains( $prop->name, $prop->namespace ) )
	{
	$toStorage->attach( clone $prop );
	}
	}
	$this->props[$toPath] = $toStorage;
	}

	/**
	* Overwrites ETag generation from simple backend.
	*
	* Generates an ETag based on $path and the content of $path (if available
	* and not a collection).
	*
	* @param string $path
	* @return string
	*/
	protected function getETag( $path )
	{
	return ( md5( $path ) );
	}

	/**
	* Read valid data from given content array and initialize property
	* storage.
	*
	* @param array $contents
	* @param string $path
	* @return void
	*/
	public function addContents( array $contents, $path = '/' )
	{
	foreach ( $contents as $name => $content )
	{
	if ( !is_string( $name ) )
	{
	// Ignore elements which do not have a string key
	continue;
	}

	// Full path to resource
	$resourcePath = $path . $name;

	if ( is_array( $content ) )
	{
	// Content is a collection
	$this->content[$resourcePath] = array();
	$this->props[$resourcePath] = $this->initializeProperties(
	$resourcePath,
	true
	);

	// Recurse
	$this->addContents( $content, $resourcePath . '/' );
	}
	elseif ( is_string( $content ) )
	{
	// Content is a file
	$this->content[$resourcePath] = $content;
	$this->props[$resourcePath] = $this->initializeProperties(
	$resourcePath
	);
	}
	else
	{
	// Ignore everything else...
	continue;
	}

	// Add contents to parent directory
	$parent = ( $path === '/' ? '/' : substr( $path, 0, -1 ) );
	$this->content[$parent][] = $resourcePath;
	}
	}

	/**
	* Create a new collection.
	*
	* Creates a new collection at the given path.
	*
	* @param string $path
	* @return void
	*/
	protected function createCollection( $path )
	{
	// Create collection
	$this->content[$path] = array();

	// Add collection to parent node
	$this->content[dirname( $path )][] = $path;

	// Set initial metadata for collection
	$this->props[$path] = $this->initializeProperties( $path, true );
	}

	/**
	* Create a new resource.
	*
	* Creates a new resource at the given path, optionally with the given
	* content.
	*
	* @param string $path
	* @param string $content
	* @return void
	*/
	protected function createResource( $path, $content = null )
	{
	// Create resource
	$this->content[$path] = $content;

	// Add resource to parent node
	$this->content[dirname( $path )][] = $path;

	// Set initial metadata for collection
	$this->props[$path] = $this->initializeProperties( $path, false );
	}

	/**
	* Set contents of a resource.
	*
	* Change the contents of the given resource to the given content.
	*
	* @param string $path
	* @param string $content
	* @return void
	*/
	protected function setResourceContents( $path, $content )
	{
	$this->content[$path] = $content;
	}

	/**
	* Get contents of a resource.
	*
	* @param string $path
	* @return string
	*/
	protected function getResourceContents( $path )
	{
	return $this->content[$path];
	}

	/**
	* Manually set a property on a resource to request it later.
	*
	* @param string $resource
	* @param ezcWebdavProperty $property
	* @return bool
	*/
	public function setProperty( $resource, ezcWebdavProperty $property )
	{
	// Live properties may not be updated by a client.
	if ( $this->options->failingOperations & ezcWebdavMemoryBackendOptions::REQUEST_PROPPATCH )
	{
	return false;
	}

	// Bail out, if the resource is not known yet.
	if ( !array_key_exists( $resource, $this->props ) )
	{
	return false;
	}

	$this->props[$resource]->attach( $property );
	return true;
	}

	/**
	* Manually remove a property from a resource.
	*
	* @param string $resource
	* @param ezcWebdavProperty $property
	* @return bool
	*/
	public function removeProperty( $resource, ezcWebdavProperty $property )
	{
	// Live properties may not be removed.
	if ( $property instanceof ezcWebdavLiveProperty )
	{
	return false;
	}

	$this->props[$resource]->detach( $property->name, $property->namespace );
	return true;
	}

	/**
	* Reset property storage for a resource.
	*
	* @param string $resource
	* @param ezcWebdavPropertyStorage $properties
	* @return bool
	*/
	public function resetProperties( $resource, ezcWebdavPropertyStorage $properties )
	{
	$this->props[$resource] = $properties;
	}

	/**
	* Manually get a property on a resource.
	*
	* Get the property with the given name from the given resource. You may
	* optionally define a namespace to receive the property from.
	*
	* @param string $resource
	* @param string $propertyName
	* @param string $namespace
	* @return ezcWebdavProperty
	*/
	public function getProperty( $resource, $propertyName, $namespace = 'DAV:' )
	{
	return $this->props[$resource]->get( $propertyName, $namespace );
	}

	/**
	* Manually get a property on a resource.
	*
	* Get all properties for the given resource as a {@link
	* ezcWebdavPropertyStorage}
	*
	* @param string $resource
	* @return ezcWebdavBasicPropertyStorage
	*/
	public function getAllProperties( $resource )
	{
	return $this->props[$resource];
	}

	/**
	* Copy resources recursively from one path to another.
	*
	* Returns an array with {@link ezcWebdavErrorResponse}s for all subtree,
	* where the copy operation failed. Errors subsequent nodes in a subtree
	* should be ommitted.
	*
	* If an empty array is return, the operation has been completed
	* successfully.
	*
	* @param string $fromPath
	* @param string $toPath
	* @param int $depth
	* @return array(ezcWebdavErrorResponse)
	*/
	protected function performCopy( $fromPath, $toPath, $depth = ezcWebdavRequest::DEPTH_INFINITY )
	{
	$causeErrors = (bool) ( $this->options->failingOperations & ( ezcWebdavMemoryBackendOptions::REQUEST_COPY \| ezcWebdavMemoryBackendOptions::REQUEST_MOVE ) );
	$errors = array();

	if ( !is_array( $this->content[$fromPath] ) \|\|
	( is_array( $this->content[$fromPath] ) && ( $depth === ezcWebdavRequest::DEPTH_ZERO ) ) )
	{
	// Copy a resource, or a collection, but the depth header told not
	// to recurse into collections
	if ( $causeErrors && preg_match( $this->options->failForRegexp, $fromPath ) > 0 )
	{
	// Completely abort with error
	return array( ezcWebdavErrorResponse(
	ezcWebdavResponse::STATUS_423,
	$fromPath
	) );
	}
	if ( $causeErrors && preg_match( $this->options->failForRegexp, $toPath ) > 0 )
	{
	// Completely abort with error
	return array( ezcWebdavErrorResponse(
	ezcWebdavResponse::STATUS_412,
	$toPath
	) );
	}

	// Perform copy operation
	if ( is_array( $this->content[$fromPath] ) )
	{
	// Create a new empty collection
	$this->content[$toPath] = array();
	}
	else
	{
	// Copy file content
	$this->content[$toPath] = $this->content[$fromPath];
	}

	// Copy properties
	$this->cloneProperties(
	$toPath,
	is_array( $this->content[$toPath] ),
	$this->props[$fromPath]
	);

	// Add to parent node
	$this->content[dirname( $toPath )][] = $toPath;
	}
	else
	{
	// Copy a collection
	$errnousSubtrees = array();

	// Array of copied collections, where the child names are required
	// to be modified depending on the success of the copy operation.
	$copiedCollections = array();

	// Check all nodes, if they math the fromPath
	foreach ( $this->content as $resource => $content )
	{
	if ( strpos( $resource, $fromPath ) !== 0 )
	{
	// This resource is not affected by the copy operation
	continue;
	}

	// Check if this resource should be skipped, because
	// already one of the parent nodes caused an error.
	foreach ( $errnousSubtrees as $subtree )
	{
	if ( strpos( $resource, $subtree ) )
	{
	// Skip resource, then.
	continue 2;
	}
	}

	// Check if this resource should cause an error
	if ( $causeErrors && preg_match( $this->options->failForRegexp, $resource ) )
	{
	// Cause an error and skip resource
	$errors[] = new ezcWebdavErrorResponse(
	ezcWebdavResponse::STATUS_423,
	$resource
	);
	continue;
	}

	// To actually perform the copy operation, modify the
	// destination resource name
	$newResourceName = preg_replace( '(^' . preg_quote( $fromPath ) . ')', $toPath, $resource );

	// Check if this resource should cause an error
	if ( $causeErrors && preg_match( $this->options->failForRegexp, $newResourceName ) )
	{
	// Cause an error and skip resource
	$errors[] = new ezcWebdavErrorResponse(
	ezcWebdavResponse::STATUS_412,
	$newResourceName
	);
	continue;
	}

	// Add collection to collection child recalculation array
	if ( is_array( $this->content[$resource] ) )
	{
	$copiedCollections[] = $newResourceName;
	}

	// Actually copy
	$this->content[$newResourceName] = $this->content[$resource];

	// Copy properties
	$this->cloneProperties(
	$newResourceName,
	is_array( $this->content[$resource] ),
	$this->props[$resource]
	);

	// Add to parent node
	$this->content[dirname( $newResourceName )][] = $newResourceName;
	}

	// Iterate over all copied collections and update the child
	// references
	foreach ( $copiedCollections as $collection )
	{
	foreach ( $this->content[$collection] as $nr => $child )
	{
	foreach ( $errnousSubtrees as $subtree )
	{
	if ( strpos( $child, $subtree ) )
	{
	// If child caused an error, it has not been
	// copied, so we remove it.
	unset( $this->content[$collection][$nr] );
	continue 2;
	}
	}

	// Also remove all references to old children, new children
	// have already been added during the last step.
	if ( preg_match( '(^' . preg_quote( $fromPath ) . ')', $child ) )
	{
	unset( $this->content[$collection][$nr] );
	}
	}

	$this->content[$collection] = array_values( $this->content[$collection] );
	}
	}

	return $errors;
	}

	/**
	* Delete everything below this path.
	*
	* Returns an error response if the deletion failed, and null on success.
	*
	* @param string $path
	* @return ezcWebdavErrorResponse
	*/
	protected function performDelete( $path )
	{
	// Check if any errors would occur during deletion process
	$error = array();
	foreach ( $this->content as $name => $content )
	{
	if ( strpos( $name, $path ) === 0 && ( substr( $name, strlen( $path ), 1 ) === '/' \|\| $name === $path ) )
	{
	// Check if we want to cause some errors here.
	if ( $this->options->failingOperations & ezcWebdavMemoryBackendOptions::REQUEST_DELETE && preg_match( $this->options->failForRegexp, $name ) > 0 )
	{
	$error[] = new ezcWebdavErrorResponse(
	ezcWebdavResponse::STATUS_423,
	$name
	);
	}
	}
	}

	// If errors occured, return them
	if ( count( $error ) )
	{
	return new ezcWebdavMultistatusResponse(
	$error
	);
	}

	// Remove all content nodes starting with requested path
	foreach ( $this->content as $name => $content )
	{
	if ( strpos( $name, $path ) === 0 && ( substr( $name, strlen( $path ), 1 ) === '/' \|\| $name === $path ) )
	{
	unset( $this->content[$name] );
	unset( $this->props[$name] );
	}
	}

	// Remove parent node assignement to removed node
	$id = array_search( $path, $this->content[$parent = dirname( $path )] );
	if ( $id !== false )
	{
	unset( $this->content[$parent][$id] );
	$this->content[$parent] = array_values( $this->content[$parent] );
	}

	return null;
	}

	/**
	* Check if node exists.
	*
	* Check if a node exists with the given path.
	*
	* @param string $path
	* @return bool
	*
	* @access protected
	*/
	public function nodeExists( $path )
	{
	return isset( $this->content[$path] );
	}

	/**
	* Check if node is a collection.
	*
	* Check if the node behind the given path is a collection.
	*
	* @param string $path
	* @return bool
	*
	* @access protected
	*/
	public function isCollection( $path )
	{
	return $this->nodeExists( $path ) && is_array( $this->content[$path] );
	}

	/**
	* Get members of collection.
	*
	* Returns an array with the members of the collection given by the path of
	* the collection.
	*
	* The returned array holds elements which are either ezcWebdavCollection,
	* or ezcWebdavResource.
	*
	* @param string $path
	* @return array
	*/
	protected function getCollectionMembers( $path )
	{
	$contents = array();

	foreach ( $this->content[$path] as $child )
	{
	if ( is_array( $this->content[$child] ) )
	{
	// Add collection without any children
	$contents[] = new ezcWebdavCollection(
	$child
	);
	}
	else
	{
	// Add files without content
	$contents[] = new ezcWebdavResource(
	$child
	);
	}
	}

	return $contents;
	}

	/**
	* Clones the memory backend deeply.
	*
	* @return void
	*/
	public function __clone()
	{
	foreach ( $this->props as $path => $propStorage )
	{
	$this->props[$path] = clone $propStorage;
	}
	}
	}

	?>