server/lib/filesystemview.php

<?php

/**
 * ownCloud
 *
 * @author Frank Karlitschek
 * @copyright 2012 Frank Karlitschek frank@owncloud.org
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
 *
 * You should have received a copy of the GNU Affero General Public
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */


/**
 * Class to provide access to ownCloud filesystem via a "view", and methods for
 * working with files within that view (e.g. read, write, delete, etc.). Each
 * view is restricted to a set of directories via a virtual root. The default view
 * uses the currently logged in user's data directory as root (parts of
 * OC_Filesystem are merely a wrapper for OC_FilesystemView).
 *
 * Apps that need to access files outside of the user data folders (to modify files
 * belonging to a user other than the one currently logged in, for example) should
 * use this class directly rather than using OC_Filesystem, or making use of PHP's
 * built-in file manipulation functions. This will ensure all hooks and proxies
 * are triggered correctly.
 *
 * Filesystem functions are not called directly; they are passed to the correct
 * OC_Filestorage object
 */

class OC_FilesystemView {
	private $fakeRoot='';
	private $internal_path_cache=array();
	private $storage_cache=array();

	public function __construct($root) {
		$this->fakeRoot=$root;
	}

	public function getAbsolutePath($path) {
		if(!$path){
			$path='/';
		}
		if($path[0]!=='/'){
			$path='/'.$path;
		}
		return $this->fakeRoot.$path;
	}
	
	/**
	* change the root to a fake toor
	* @param  string  fakeRoot
	* @return bool
	*/
	public function chroot($fakeRoot) {
		if(!$fakeRoot==''){
			if($fakeRoot[0]!=='/') {
				$fakeRoot='/'.$fakeRoot;
			}
		}
		$this->fakeRoot=$fakeRoot;
	}

	/**
	 * get the fake root
	 * @return string
	 */
	public function getRoot() {
		return $this->fakeRoot;
	}

	/**
	* get the part of the path relative to the mountpoint of the storage it's stored in
	* @param  string  path
	* @return bool
	*/
	public function getInternalPath($path) {
		if (!isset($this->internal_path_cache[$path])) {
			$this->internal_path_cache[$path] = OC_Filesystem::getInternalPath($this->getAbsolutePath($path));
		}
		return $this->internal_path_cache[$path];
	}

	/**
	 * get path relative to the root of the view
	 * @param string path
	 * @return string
	 */
	public function getRelativePath($path) {
		if($this->fakeRoot=='') {
			return $path;
		}
		if(strpos($path, $this->fakeRoot)!==0) {
			return null;
		}else{
			$path=substr($path, strlen($this->fakeRoot));
			if(strlen($path)===0){
				return '/';
			}else{
				return $path;
			}
		}
	}

	/**
	* get the storage object for a path
	* @param string path
	* @return OC_Filestorage
	*/
	public function getStorage($path) {
		if (!isset($this->storage_cache[$path])) {
			$this->storage_cache[$path] = OC_Filesystem::getStorage($this->getAbsolutePath($path));
		}
		return $this->storage_cache[$path];
	}

	/**
	* get the mountpoint of the storage object for a path
	( note: because a storage is not always mounted inside the fakeroot, the returned mountpoint is relative to the absolute root of the filesystem and doesn't take the chroot into account
	*
	* @param string path
	* @return string
	*/
	public function getMountPoint($path) {
		return OC_Filesystem::getMountPoint($this->getAbsolutePath($path));
	}

	/**
	* return the path to a local version of the file
	* we need this because we can't know if a file is stored local or not from outside the filestorage and for some purposes a local file is needed
	* @param string path
	* @return string
	*/
	public function getLocalFile($path) {
		$parent=substr($path, 0, strrpos($path,'/'));
		if(OC_Filesystem::isValidPath($parent) and $storage=$this->getStorage($path)) {
			return $storage->getLocalFile($this->getInternalPath($path));
		}
	}

	/**
	 * the following functions operate with arguments and return values identical
	 * to those of their PHP built-in equivalents. Mostly they are merely wrappers
	 * for OC_Filestorage via basicOperation().
	 */
	public function mkdir($path) {
		return $this->basicOperation('mkdir', $path, array('create', 'write'));
	}
	public function rmdir($path) {
		return $this->basicOperation('rmdir', $path, array('delete'));
	}
	public function opendir($path) {
		return $this->basicOperation('opendir', $path, array('read'));
	}
	public function readdir($handle) {
		$fsLocal= new OC_Filestorage_Local( array( 'datadir' => '/' ) );
		return $fsLocal->readdir( $handle );
	}
	public function is_dir($path) {
		if($path=='/'){
			return true;
		}
		return $this->basicOperation('is_dir', $path);
	}
	public function is_file($path) {
		if($path=='/'){
			return false;
		}
		return $this->basicOperation('is_file', $path);
	}
	public function stat($path) {
		return $this->basicOperation('stat', $path);
	}
	public function filetype($path) {
		return $this->basicOperation('filetype', $path);
	}
	public function filesize($path) {
		return $this->basicOperation('filesize', $path);
	}
	public function readfile($path) {
		@ob_end_clean();
		$handle=$this->fopen($path, 'rb');
		if ($handle) {
			$chunkSize = 8192;// 8 MB chunks
			while (!feof($handle)) {
				echo fread($handle, $chunkSize);
				flush();
			}
			$size=$this->filesize($path);
			return $size;
		}
		return false;
	}
	public function is_readable($path) {
		return $this->basicOperation('is_readable', $path);
	}
	public function is_writable($path) {
		return $this->basicOperation('is_writable', $path);
	}
	public function file_exists($path) {
		if($path=='/'){
			return true;
		}
		return $this->basicOperation('file_exists', $path);
	}
	public function filectime($path) {
		return $this->basicOperation('filectime', $path);
	}
	public function filemtime($path) {
		return $this->basicOperation('filemtime', $path);
	}
	public function touch($path, $mtime=null) {
		return $this->basicOperation('touch', $path, array('write'), $mtime);
	}
	public function file_get_contents($path) {
		return $this->basicOperation('file_get_contents', $path, array('read'));
	}
	public function file_put_contents($path, $data) {
		if(is_resource($data)) {//not having to deal with streams in file_put_contents makes life easier
			$absolutePath = OC_Filesystem::normalizePath($this->getAbsolutePath($path));
			if (OC_FileProxy::runPreProxies('file_put_contents', $absolutePath, $data) && OC_Filesystem::isValidPath($path)) {
				$path = $this->getRelativePath($absolutePath);
				$exists = $this->file_exists($path);
				$run = true;
				if(!$exists) {
					OC_Hook::emit(
						OC_Filesystem::CLASSNAME,
						OC_Filesystem::signal_create,
						array(
							OC_Filesystem::signal_param_path => $path,
							OC_Filesystem::signal_param_run => &$run
						)
					);
				}
				OC_Hook::emit(
					OC_Filesystem::CLASSNAME,
					OC_Filesystem::signal_write,
					array(
						OC_Filesystem::signal_param_path => $path,
						OC_Filesystem::signal_param_run => &$run
					)
				);
				if(!$run) {
					return false;
				}
				$target=$this->fopen($path, 'w');
				if($target) {
					$count=OC_Helper::streamCopy($data, $target);
					fclose($target);
					fclose($data);
					if(!$exists) {
						OC_Hook::emit(
							OC_Filesystem::CLASSNAME,
							OC_Filesystem::signal_post_create,
							array( OC_Filesystem::signal_param_path => $path)
						);
					}
					OC_Hook::emit(
						OC_Filesystem::CLASSNAME,
						OC_Filesystem::signal_post_write,
						array( OC_Filesystem::signal_param_path => $path)
					);
					OC_FileProxy::runPostProxies('file_put_contents', $absolutePath, $count);
					return $count > 0;
				}else{
					return false;
				}
			}
		}else{
			return $this->basicOperation('file_put_contents', $path, array('create', 'write'), $data);
		}
	}
	public function unlink($path) {
		return $this->basicOperation('unlink', $path, array('delete'));
	}
	public function deleteAll( $directory, $empty = false ) {
		return $this->basicOperation( 'deleteAll', $directory, array('delete'), $empty );
	}
	public function rename($path1, $path2) {
		$postFix1=(substr($path1,-1,1)==='/')?'/':'';
		$postFix2=(substr($path2,-1,1)==='/')?'/':'';
		$absolutePath1 = OC_Filesystem::normalizePath($this->getAbsolutePath($path1));
		$absolutePath2 = OC_Filesystem::normalizePath($this->getAbsolutePath($path2));
		if(OC_FileProxy::runPreProxies('rename', $absolutePath1, $absolutePath2) and OC_Filesystem::isValidPath($path2)) {
			$path1 = $this->getRelativePath($absolutePath1);
			$path2 = $this->getRelativePath($absolutePath2);
			
			if($path1 == null or $path2 == null) {
				return false;
			}
			$run=true;
			OC_Hook::emit(
				OC_Filesystem::CLASSNAME, OC_Filesystem::signal_rename,
					array(
						OC_Filesystem::signal_param_oldpath => $path1,
						OC_Filesystem::signal_param_newpath => $path2,
						OC_Filesystem::signal_param_run => &$run
					)
			);
			if($run) {
				$mp1 = $this->getMountPoint($path1.$postFix1);
				$mp2 = $this->getMountPoint($path2.$postFix2);
				if($mp1 == $mp2) {
					if($storage = $this->getStorage($path1)) {
						$result = $storage->rename($this->getInternalPath($path1.$postFix1), $this->getInternalPath($path2.$postFix2));
					}
				} else {
					$source = $this->fopen($path1.$postFix1, 'r');
					$target = $this->fopen($path2.$postFix2, 'w');
					$count = OC_Helper::streamCopy($source, $target);
					$storage1 = $this->getStorage($path1);
					$storage1->unlink($this->getInternalPath($path1.$postFix1));
					$result = $count>0;
				} 
				OC_Hook::emit(
					OC_Filesystem::CLASSNAME,
					OC_Filesystem::signal_post_rename,
					array(
						OC_Filesystem::signal_param_oldpath => $path1,
						OC_Filesystem::signal_param_newpath => $path2
					)
				);
				return $result;
			}
		}
	}
	public function copy($path1, $path2) {
		$postFix1=(substr($path1,-1,1)==='/')?'/':'';
		$postFix2=(substr($path2,-1,1)==='/')?'/':'';
		$absolutePath1 = OC_Filesystem::normalizePath($this->getAbsolutePath($path1));
		$absolutePath2 = OC_Filesystem::normalizePath($this->getAbsolutePath($path2));
		if(OC_FileProxy::runPreProxies('copy', $absolutePath1, $absolutePath2) and OC_Filesystem::isValidPath($path2)) {
			$path1 = $this->getRelativePath($absolutePath1);
			$path2 = $this->getRelativePath($absolutePath2);
			
			if($path1 == null or $path2 == null) {
				return false;
			}
			$run=true;
			OC_Hook::emit(
				OC_Filesystem::CLASSNAME,
				OC_Filesystem::signal_copy,
				array(
					OC_Filesystem::signal_param_oldpath => $path1,
					OC_Filesystem::signal_param_newpath=>$path2,
					OC_Filesystem::signal_param_run => &$run
				)
			);
			$exists=$this->file_exists($path2);
			if($run and !$exists) {
				OC_Hook::emit(
					OC_Filesystem::CLASSNAME,
					OC_Filesystem::signal_create,
					array(
						OC_Filesystem::signal_param_path => $path2,
						OC_Filesystem::signal_param_run => &$run
					)
				);
			}
			if($run) {
				OC_Hook::emit(
					OC_Filesystem::CLASSNAME,
					OC_Filesystem::signal_write,
					array(
						OC_Filesystem::signal_param_path => $path2,
						OC_Filesystem::signal_param_run => &$run
					)
				);
			}
			if($run) {
				$mp1=$this->getMountPoint($path1.$postFix1);
				$mp2=$this->getMountPoint($path2.$postFix2);
				if($mp1 == $mp2){
					if($storage = $this->getStorage($path1.$postFix1)) {
						$result=$storage->copy($this->getInternalPath($path1.$postFix1), $this->getInternalPath($path2.$postFix2));
					}
				} else {
					$source = $this->fopen($path1.$postFix1, 'r');
					$target = $this->fopen($path2.$postFix2, 'w');
					$result = OC_Helper::streamCopy($source, $target);
				}
				OC_Hook::emit(
					OC_Filesystem::CLASSNAME,
					OC_Filesystem::signal_post_copy,
					array(
						OC_Filesystem::signal_param_oldpath => $path1,
						OC_Filesystem::signal_param_newpath=>$path2
					)
				);
				if(!$exists) {
					OC_Hook::emit(
						OC_Filesystem::CLASSNAME,
						OC_Filesystem::signal_post_create,
						array(OC_Filesystem::signal_param_path => $path2)
					);
				}
				OC_Hook::emit(
					OC_Filesystem::CLASSNAME,
					OC_Filesystem::signal_post_write,
					array( OC_Filesystem::signal_param_path => $path2)
				);
				return $result;
			}
		}
	}
	public function fopen($path, $mode) {
		$hooks=array();
		switch($mode) {
			case 'r':
			case 'rb':
				$hooks[]='read';
				break;
			case 'r+':
			case 'rb+':
			case 'w+':
			case 'wb+':
			case 'x+':
			case 'xb+':
			case 'a+':
			case 'ab+':
				$hooks[]='read';
				$hooks[]='write';
				break;
			case 'w':
			case 'wb':
			case 'x':
			case 'xb':
			case 'a':
			case 'ab':
				$hooks[]='write';
				break;
			default:
				OC_Log::write('core','invalid mode ('.$mode.') for '.$path,OC_Log::ERROR);
		}

		return $this->basicOperation('fopen', $path, $hooks, $mode);
	}
	public function toTmpFile($path) {
		if(OC_Filesystem::isValidPath($path)) {
			$source = $this->fopen($path, 'r');
			if($source) {
				$extension='';
				$extOffset=strpos($path, '.');
				if($extOffset !== false) {
					$extension=substr($path, strrpos($path,'.'));
				}
				$tmpFile = OC_Helper::tmpFile($extension);
				file_put_contents($tmpFile, $source);
				return $tmpFile;
			}
		}
	}
	public function fromTmpFile($tmpFile, $path) {
		if(OC_Filesystem::isValidPath($path)) {
			if(!$tmpFile) {
				debug_print_backtrace();
			}
			$source=fopen($tmpFile, 'r');
			if($source) {
				$this->file_put_contents($path, $source);
				unlink($tmpFile);
				return true;
			} else {
			}
		} else {
			return false;
		}
	}

	public function getMimeType($path) {
		return $this->basicOperation('getMimeType', $path);
	}
	public function hash($type, $path, $raw = false) {
		$postFix=(substr($path,-1,1)==='/')?'/':'';
		$absolutePath = OC_Filesystem::normalizePath($this->getAbsolutePath($path));
		if (OC_FileProxy::runPreProxies('hash', $absolutePath) && OC_Filesystem::isValidPath($path)) {
			$path = $this->getRelativePath($absolutePath);
			if ($path == null) {
				return false;
			}
			if (OC_Filesystem::$loaded && $this->fakeRoot == OC_Filesystem::getRoot()) {
				OC_Hook::emit(
					OC_Filesystem::CLASSNAME,
					OC_Filesystem::signal_read,
					array( OC_Filesystem::signal_param_path => $path)
				);
			}
			if ($storage = $this->getStorage($path.$postFix)) {
				$result = $storage->hash($type, $this->getInternalPath($path.$postFix), $raw);
				$result = OC_FileProxy::runPostProxies('hash', $absolutePath, $result);
				return $result;
			}
		}
		return null;
	}

	public function free_space($path='/') {
		return $this->basicOperation('free_space', $path);
	}

	/**
	 * @brief abstraction layer for basic filesystem functions: wrapper for OC_Filestorage
	 * @param string $operation
	 * @param string #path
	 * @param array (optional) hooks
	 * @param mixed (optional) $extraParam
	 * @return mixed
	 *
	 * This method takes requests for basic filesystem functions (e.g. reading & writing
	 * files), processes hooks and proxies, sanitises paths, and finally passes them on to
	 * OC_Filestorage for delegation to a storage backend for execution
	 */
	private function basicOperation($operation, $path, $hooks=array(), $extraParam=null) {
		$postFix=(substr($path,-1,1)==='/')?'/':'';
		$absolutePath = OC_Filesystem::normalizePath($this->getAbsolutePath($path));
		if(OC_FileProxy::runPreProxies($operation, $absolutePath, $extraParam) and OC_Filesystem::isValidPath($path)) {
			$path = $this->getRelativePath($absolutePath);
			if($path == null) {
				return false;
			}
			$internalPath = $this->getInternalPath($path.$postFix);
			$run=$this->runHooks($hooks,$path);
			if($run and $storage = $this->getStorage($path.$postFix)) {
				if(!is_null($extraParam)) {
					$result = $storage->$operation($internalPath, $extraParam);
				} else {
					$result = $storage->$operation($internalPath);
				}
				$result = OC_FileProxy::runPostProxies($operation, $this->getAbsolutePath($path), $result);
				if(OC_Filesystem::$loaded and $this->fakeRoot==OC_Filesystem::getRoot()) {
					if($operation!='fopen') {//no post hooks for fopen, the file stream is still open
						$this->runHooks($hooks,$path,true);
					}
				}
				return $result;
			}
		}
		return null;
	}

	private function runHooks($hooks,$path,$post=false){
		$prefix=($post)?'post_':'';
		$run=true;
		if(OC_Filesystem::$loaded and $this->fakeRoot==OC_Filesystem::getRoot()) {
			foreach($hooks as $hook) {
				if($hook!='read') {
					OC_Hook::emit(
						OC_Filesystem::CLASSNAME,
						$prefix.$hook,
						array(
							OC_Filesystem::signal_param_run => &$run,
							OC_Filesystem::signal_param_path => $path
						)
					);
				} elseif(!$post) {
					OC_Hook::emit(
						OC_Filesystem::CLASSNAME,
						$prefix.$hook,
						array(
							OC_Filesystem::signal_param_path => $path
						)
					);
				}
			}
		}
		return $run;
	}

	/**
	 * check if a file or folder has been updated since $time
	 * @param int $time
	 * @return bool
	 */
	public function hasUpdated($path, $time) {
		return $this->basicOperation('hasUpdated', $path, array(), $time);
	}
}