wiki.techinc.nl/includes/upload/UploadStash.php

402 lines
15 KiB
PHP

<?php
/**
* UploadStash is intended to accomplish a few things:
* - enable applications to temporarily stash files without publishing them to the wiki.
* - Several parts of MediaWiki do this in similar ways: UploadBase, UploadWizard, and FirefoggChunkedExtension
* And there are several that reimplement stashing from scratch, in idiosyncratic ways. The idea is to unify them all here.
* Mostly all of them are the same except for storing some custom fields, which we subsume into the data array.
* - enable applications to find said files later, as long as the session or temp files haven't been purged.
* - enable the uploading user (and *ONLY* the uploading user) to access said files, and thumbnails of said files, via a URL.
* We accomplish this by making the session serve as a URL->file mapping, on the assumption that nobody else can access
* the session, even the uploading user. See SpecialUploadStash, which implements a web interface to some files stored this way.
*
*/
class UploadStash {
// Format of the key for files -- has to be suitable as a filename itself (e.g. ab12cd34ef.jpg)
const KEY_FORMAT_REGEX = '/^[\w-]+\.\w+$/';
/**
* repository that this uses to store temp files
* public because we sometimes need to get a LocalFile within the same repo.
*
* @var LocalRepo
*/
public $repo;
// array of initialized objects obtained from session (lazily initialized upon getFile())
private $files = array();
// TODO: Once UploadBase starts using this, switch to use these constants rather than UploadBase::SESSION*
// const SESSION_VERSION = 2;
// const SESSION_KEYNAME = 'wsUploadData';
/**
* Represents the session which contains temporarily stored files.
* Designed to be compatible with the session stashing code in UploadBase (should replace it eventually)
*/
public function __construct( $repo ) {
// this might change based on wiki's configuration.
$this->repo = $repo;
if ( ! isset( $_SESSION ) ) {
throw new UploadStashNotAvailableException( 'no session variable' );
}
if ( !isset( $_SESSION[UploadBase::SESSION_KEYNAME] ) ) {
$_SESSION[UploadBase::SESSION_KEYNAME] = array();
}
}
/**
* Get a file and its metadata from the stash.
* May throw exception if session data cannot be parsed due to schema change, or key not found.
*
* @param $key Integer: key
* @throws UploadStashFileNotFoundException
* @throws UploadStashBadVersionException
* @return UploadStashFile
*/
public function getFile( $key ) {
if ( ! preg_match( self::KEY_FORMAT_REGEX, $key ) ) {
throw new UploadStashBadPathException( "key '$key' is not in a proper format" );
}
if ( !isset( $this->files[$key] ) ) {
if ( !isset( $_SESSION[UploadBase::SESSION_KEYNAME][$key] ) ) {
throw new UploadStashFileNotFoundException( "key '$key' not found in stash" );
}
$data = $_SESSION[UploadBase::SESSION_KEYNAME][$key];
// guards against PHP class changing while session data doesn't
if ($data['version'] !== UploadBase::SESSION_VERSION ) {
throw new UploadStashBadVersionException( $data['version'] . " does not match current version " . UploadBase::SESSION_VERSION );
}
// separate the stashData into the path, and then the rest of the data
$path = $data['mTempPath'];
unset( $data['mTempPath'] );
$file = new UploadStashFile( $this, $this->repo, $path, $key, $data );
if ( $file->getSize() === 0 ) {
throw new UploadStashZeroLengthFileException( "File is zero length" );
}
$this->files[$key] = $file;
}
return $this->files[$key];
}
/**
* Stash a file in a temp directory and record that we did this in the session, along with other metadata.
* We store data in a flat key-val namespace because that's how UploadBase did it. This also means we have to
* ensure that the key-val pairs in $data do not overwrite other required fields.
*
* @param $path String: path to file you want stashed
* @param $data Array: optional, other data you want associated with the file. Do not use 'mTempPath', 'mFileProps', 'mFileSize', or 'version' as keys here
* @param $key String: optional, unique key for this file in this session. Used for directory hashing when storing, otherwise not important
* @throws UploadStashBadPathException
* @throws UploadStashFileException
* @return UploadStashFile: file, or null on failure
*/
public function stashFile( $path, $data = array(), $key = null ) {
if ( ! file_exists( $path ) ) {
wfDebug( "UploadStash: tried to stash file at '$path', but it doesn't exist\n" );
throw new UploadStashBadPathException( "path doesn't exist" );
}
$fileProps = File::getPropsFromPath( $path );
// we will be initializing from some tmpnam files that don't have extensions.
// most of MediaWiki assumes all uploaded files have good extensions. So, we fix this.
$extension = self::getExtensionForPath( $path );
if ( ! preg_match( "/\\.\\Q$extension\\E$/", $path ) ) {
$pathWithGoodExtension = "$path.$extension";
if ( ! rename( $path, $pathWithGoodExtension ) ) {
throw new UploadStashFileException( "couldn't rename $path to have a better extension at $pathWithGoodExtension" );
}
$path = $pathWithGoodExtension;
}
// If no key was supplied, use content hash. Also has the nice property of collapsing multiple identical files
// uploaded this session, which could happen if uploads had failed.
if ( is_null( $key ) ) {
$key = $fileProps['sha1'] . "." . $extension;
}
if ( ! preg_match( self::KEY_FORMAT_REGEX, $key ) ) {
throw new UploadStashBadPathException( "key '$key' is not in a proper format" );
}
// if not already in a temporary area, put it there
$status = $this->repo->storeTemp( basename( $path ), $path );
if( ! $status->isOK() ) {
// It is a convention in MediaWiki to only return one error per API exception, even if multiple errors
// are available. We use reset() to pick the "first" thing that was wrong, preferring errors to warnings.
// This is a bit lame, as we may have more info in the $status and we're throwing it away, but to fix it means
// redesigning API errors significantly.
// $status->value just contains the virtual URL (if anything) which is probably useless to the caller
$error = reset( $status->getErrorsArray() );
if ( ! count( $error ) ) {
$error = reset( $status->getWarningsArray() );
if ( ! count( $error ) ) {
$error = array( 'unknown', 'no error recorded' );
}
}
throw new UploadStashFileException( "error storing file in '$path': " . implode( '; ', $error ) );
}
$stashPath = $status->value;
// required info we always store. Must trump any other application info in $data
// 'mTempPath', 'mFileSize', and 'mFileProps' are arbitrary names
// chosen for compatibility with UploadBase's way of doing this.
$requiredData = array(
'mTempPath' => $stashPath,
'mFileSize' => $fileProps['size'],
'mFileProps' => $fileProps,
'version' => UploadBase::SESSION_VERSION
);
// now, merge required info and extra data into the session. (The extra data changes from application to application.
// UploadWizard wants different things than say FirefoggChunkedUpload.)
wfDebug( __METHOD__ . " storing under $key\n" );
$_SESSION[UploadBase::SESSION_KEYNAME][$key] = array_merge( $data, $requiredData );
return $this->getFile( $key );
}
/**
* Remove all files from the stash.
* Does not clean up files in the repo, just the record of them.
* @return boolean: success
*/
public function clear() {
$_SESSION[UploadBase::SESSION_KEYNAME] = array();
return true;
}
/**
* Remove a particular file from the stash.
* Does not clean up file in the repo, just the record of it.
* @return boolean: success
*/
public function removeFile( $key ) {
unset ( $_SESSION[UploadBase::SESSION_KEYNAME][$key] );
return true;
}
/**
* List all files in the stash.
*/
public function listFiles() {
return array_keys( $_SESSION[UploadBase::SESSION_KEYNAME] );
}
/**
* Find or guess extension -- ensuring that our extension matches our mime type.
* Since these files are constructed from php tempnames they may not start off
* with an extension.
* XXX this is somewhat redundant with the checks that ApiUpload.php does with incoming
* uploads versus the desired filename. Maybe we can get that passed to us...
*/
public static function getExtensionForPath( $path ) {
// Does this have an extension?
$n = strrpos( $path, '.' );
$extension = null;
if ( $n !== false ) {
$extension = $n ? substr( $path, $n + 1 ) : '';
} else {
// If not, assume that it should be related to the mime type of the original file.
$magic = MimeMagic::singleton();
$mimeType = $magic->guessMimeType( $path );
$extensions = explode( ' ', MimeMagic::singleton()->getExtensionsForType( $mimeType ) );
if ( count( $extensions ) ) {
$extension = $extensions[0];
}
}
if ( is_null( $extension ) ) {
throw new UploadStashFileException( "extension is null" );
}
return File::normalizeExtension( $extension );
}
}
class UploadStashFile extends UnregisteredLocalFile {
private $sessionStash;
private $sessionKey;
private $sessionData;
private $urlName;
protected $url;
/**
* A LocalFile wrapper around a file that has been temporarily stashed, so we can do things like create thumbnails for it
* Arguably UnregisteredLocalFile should be handling its own file repo but that class is a bit retarded currently
*
* @param $stash UploadStash: useful for obtaining config, stashing transformed files
* @param $repo FSRepo: repository where we should find the path
* @param $path String: path to file
* @param $key String: key to store the path and any stashed data under
* @param $data String: any other data we want stored with this file
* @throws UploadStashBadPathException
* @throws UploadStashFileNotFoundException
*/
public function __construct( $stash, $repo, $path, $key, $data ) {
$this->sessionStash = $stash;
$this->sessionKey = $key;
$this->sessionData = $data;
// resolve mwrepo:// urls
if ( $repo->isVirtualUrl( $path ) ) {
$path = $repo->resolveVirtualUrl( $path );
}
// check if path appears to be sane, no parent traversals, and is in this repo's temp zone.
$repoTempPath = $repo->getZonePath( 'temp' );
if ( ( ! $repo->validateFilename( $path ) ) ||
( strpos( $path, $repoTempPath ) !== 0 ) ) {
wfDebug( "UploadStash: tried to construct an UploadStashFile from a file that should already exist at '$path', but path is not valid\n" );
throw new UploadStashBadPathException( 'path is not valid' );
}
// check if path exists! and is a plain file.
if ( ! $repo->fileExists( $path, FileRepo::FILES_ONLY ) ) {
wfDebug( "UploadStash: tried to construct an UploadStashFile from a file that should already exist at '$path', but path is not found\n" );
throw new UploadStashFileNotFoundException( 'cannot find path, or not a plain file' );
}
parent::__construct( false, $repo, $path, false );
$this->name = basename( $this->path );
}
/**
* A method needed by the file transforming and scaling routines in File.php
* We do not necessarily care about doing the description at this point
* However, we also can't return the empty string, as the rest of MediaWiki demands this (and calls to imagemagick
* convert require it to be there)
*
* @return String: dummy value
*/
public function getDescriptionUrl() {
return $this->getUrl();
}
/**
* Get the path for the thumbnail (actually any transformation of this file)
* The actual argument is the result of thumbName although we seem to have
* buggy code elsewhere that expects a boolean 'suffix'
*
* @param $thumbName String: name of thumbnail (e.g. "120px-123456.jpg" ), or false to just get the path
* @return String: path thumbnail should take on filesystem, or containing directory if thumbname is false
*/
public function getThumbPath( $thumbName = false ) {
$path = dirname( $this->path );
if ( $thumbName !== false ) {
$path .= "/$thumbName";
}
return $path;
}
/**
* Return the file/url base name of a thumbnail with the specified parameters.
* We override this because we want to use the pretty url name instead of the
* ugly file name.
*
* @param $params Array: handler-specific parameters
* @return String: base name for URL, like '120px-12345.jpg', or null if there is no handler
*/
function thumbName( $params ) {
return $this->generateThumbName( $this->getUrlName(), $params );
}
/**
* Helper function -- given a 'subpage', return the local URL e.g. /wiki/Special:UploadStash/subpage
* @param {String} $subPage
* @return {String} local URL for this subpage in the Special:UploadStash space.
*/
private function getSpecialUrl( $subPage ) {
return SpecialPage::getTitleFor( 'UploadStash', $subPage )->getLocalURL();
}
/**
* Get a URL to access the thumbnail
* This is required because the model of how files work requires that
* the thumbnail urls be predictable. However, in our model the URL is not based on the filename
* (that's hidden in the session)
*
* @param $thumbName String: basename of thumbnail file -- however, we don't want to use the file exactly
* @return String: URL to access thumbnail, or URL with partial path
*/
public function getThumbUrl( $thumbName = false ) {
wfDebug( __METHOD__ . " getting for $thumbName \n" );
return $this->getSpecialUrl( 'thumb/' . $this->getUrlName() . '/' . $thumbName );
}
/**
* The basename for the URL, which we want to not be related to the filename.
* Will also be used as the lookup key for a thumbnail file.
*
* @return String: base url name, like '120px-123456.jpg'
*/
public function getUrlName() {
if ( ! $this->urlName ) {
$this->urlName = $this->sessionKey;
}
return $this->urlName;
}
/**
* Return the URL of the file, if for some reason we wanted to download it
* We tend not to do this for the original file, but we do want thumb icons
*
* @return String: url
*/
public function getUrl() {
if ( !isset( $this->url ) ) {
$this->url = $this->getSpecialUrl( 'file/' . $this->getUrlName() );
}
return $this->url;
}
/**
* Parent classes use this method, for no obvious reason, to return the path (relative to wiki root, I assume).
* But with this class, the URL is unrelated to the path.
*
* @return String: url
*/
public function getFullUrl() {
return $this->getUrl();
}
/**
* Getter for session key (the session-unique id by which this file's location & metadata is stored in the session)
*
* @return String: session key
*/
public function getSessionKey() {
return $this->sessionKey;
}
/**
* Remove the associated temporary file
* @return Status: success
*/
public function remove() {
return $this->repo->freeTemp( $this->path );
}
}
class UploadStashNotAvailableException extends MWException {};
class UploadStashFileNotFoundException extends MWException {};
class UploadStashBadPathException extends MWException {};
class UploadStashBadVersionException extends MWException {};
class UploadStashFileException extends MWException {};
class UploadStashZeroLengthFileException extends MWException {};