Current File : //www/varak.net/wiki.varak.net/includes/media/MediaHandler.php
<?php
/**
* Media-handling base classes and generic functionality.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Media
*/
use MediaWiki\MediaWikiServices;
/**
* Base media handler class
*
* @ingroup Media
*/
abstract class MediaHandler {
const TRANSFORM_LATER = 1;
const METADATA_GOOD = true;
const METADATA_BAD = false;
const METADATA_COMPATIBLE = 2; // for old but backwards compatible.
/**
* Max length of error logged by logErrorForExternalProcess()
*/
const MAX_ERR_LOG_SIZE = 65535;
/**
* Get a MediaHandler for a given MIME type from the instance cache
*
* @param string $type
* @return MediaHandler|bool
*/
static function getHandler( $type ) {
return MediaWikiServices::getInstance()
->getMediaHandlerFactory()->getHandler( $type );
}
/**
* Get an associative array mapping magic word IDs to parameter names.
* Will be used by the parser to identify parameters.
*/
abstract public function getParamMap();
/**
* Validate a thumbnail parameter at parse time.
* Return true to accept the parameter, and false to reject it.
* If you return false, the parser will do something quiet and forgiving.
*
* @param string $name
* @param mixed $value
*/
abstract public function validateParam( $name, $value );
/**
* Merge a parameter array into a string appropriate for inclusion in filenames
*
* @param array $params Array of parameters that have been through normaliseParams.
* @return string
*/
abstract public function makeParamString( $params );
/**
* Parse a param string made with makeParamString back into an array
*
* @param string $str The parameter string without file name (e.g. 122px)
* @return array|bool Array of parameters or false on failure.
*/
abstract public function parseParamString( $str );
/**
* Changes the parameter array as necessary, ready for transformation.
* Should be idempotent.
* Returns false if the parameters are unacceptable and the transform should fail
* @param File $image
* @param array &$params
*/
abstract function normaliseParams( $image, &$params );
/**
* Get an image size array like that returned by getimagesize(), or false if it
* can't be determined.
*
* This function is used for determining the width, height and bitdepth directly
* from an image. The results are stored in the database in the img_width,
* img_height, img_bits fields.
*
* @note If this is a multipage file, return the width and height of the
* first page.
*
* @param File|FSFile $image The image object, or false if there isn't one.
* Warning, FSFile::getPropsFromPath might pass an FSFile instead of File (!)
* @param string $path The filename
* @return array|bool Follow the format of PHP getimagesize() internal function.
* See https://secure.php.net/getimagesize. MediaWiki will only ever use the
* first two array keys (the width and height), and the 'bits' associative
* key. All other array keys are ignored. Returning a 'bits' key is optional
* as not all formats have a notion of "bitdepth". Returns false on failure.
*/
abstract function getImageSize( $image, $path );
/**
* Get handler-specific metadata which will be saved in the img_metadata field.
*
* @param File|FSFile $image The image object, or false if there isn't one.
* Warning, FSFile::getPropsFromPath might pass an FSFile instead of File (!)
* @param string $path The filename
* @return string A string of metadata in php serialized form (Run through serialize())
*/
function getMetadata( $image, $path ) {
return '';
}
/**
* Get metadata version.
*
* This is not used for validating metadata, this is used for the api when returning
* metadata, since api content formats should stay the same over time, and so things
* using ForeignApiRepo can keep backwards compatibility
*
* All core media handlers share a common version number, and extensions can
* use the GetMetadataVersion hook to append to the array (they should append a unique
* string so not to get confusing). If there was a media handler named 'foo' with metadata
* version 3 it might add to the end of the array the element 'foo=3'. if the core metadata
* version is 2, the end version string would look like '2;foo=3'.
*
* @return string Version string
*/
static function getMetadataVersion() {
$version = [ '2' ]; // core metadata version
Hooks::run( 'GetMetadataVersion', [ &$version ] );
return implode( ';', $version );
}
/**
* Convert metadata version.
*
* By default just returns $metadata, but can be used to allow
* media handlers to convert between metadata versions.
*
* @param string|array $metadata Metadata array (serialized if string)
* @param int $version Target version
* @return array Serialized metadata in specified version, or $metadata on fail.
*/
function convertMetadataVersion( $metadata, $version = 1 ) {
if ( !is_array( $metadata ) ) {
// unserialize to keep return parameter consistent.
Wikimedia\suppressWarnings();
$ret = unserialize( $metadata );
Wikimedia\restoreWarnings();
return $ret;
}
return $metadata;
}
/**
* Get a string describing the type of metadata, for display purposes.
*
* @note This method is currently unused.
* @param File $image
* @return string
*/
function getMetadataType( $image ) {
return false;
}
/**
* Check if the metadata string is valid for this handler.
* If it returns MediaHandler::METADATA_BAD (or false), Image
* will reload the metadata from the file and update the database.
* MediaHandler::METADATA_GOOD for if the metadata is a-ok,
* MediaHandler::METADATA_COMPATIBLE if metadata is old but backwards
* compatible (which may or may not trigger a metadata reload).
*
* @note Returning self::METADATA_BAD will trigger a metadata reload from
* file on page view. Always returning this from a broken file, or suddenly
* triggering as bad metadata for a large number of files can cause
* performance problems.
* @param File $image
* @param string $metadata The metadata in serialized form
* @return bool
*/
function isMetadataValid( $image, $metadata ) {
return self::METADATA_GOOD;
}
/**
* Get an array of standard (FormatMetadata type) metadata values.
*
* The returned data is largely the same as that from getMetadata(),
* but formatted in a standard, stable, handler-independent way.
* The idea being that some values like ImageDescription or Artist
* are universal and should be retrievable in a handler generic way.
*
* The specific properties are the type of properties that can be
* handled by the FormatMetadata class. These values are exposed to the
* user via the filemetadata parser function.
*
* Details of the response format of this function can be found at
* https://www.mediawiki.org/wiki/Manual:File_metadata_handling
* tl/dr: the response is an associative array of
* properties keyed by name, but the value can be complex. You probably
* want to call one of the FormatMetadata::flatten* functions on the
* property values before using them, or call
* FormatMetadata::getFormattedData() on the full response array, which
* transforms all values into prettified, human-readable text.
*
* Subclasses overriding this function must return a value which is a
* valid API response fragment (all associative array keys are valid
* XML tagnames).
*
* Note, if the file simply has no metadata, but the handler supports
* this interface, it should return an empty array, not false.
*
* @param File $file
* @return array|bool False if interface not supported
* @since 1.23
*/
public function getCommonMetaArray( File $file ) {
return false;
}
/**
* Get a MediaTransformOutput object representing an alternate of the transformed
* output which will call an intermediary thumbnail assist script.
*
* Used when the repository has a thumbnailScriptUrl option configured.
*
* Return false to fall back to the regular getTransform().
* @param File $image
* @param string $script
* @param array $params
* @return bool|ThumbnailImage
*/
function getScriptedTransform( $image, $script, $params ) {
return false;
}
/**
* Get a MediaTransformOutput object representing the transformed output. Does not
* actually do the transform.
*
* @param File $image
* @param string $dstPath Filesystem destination path
* @param string $dstUrl Destination URL to use in output HTML
* @param array $params Arbitrary set of parameters validated by $this->validateParam()
* @return MediaTransformOutput
*/
final function getTransform( $image, $dstPath, $dstUrl, $params ) {
return $this->doTransform( $image, $dstPath, $dstUrl, $params, self::TRANSFORM_LATER );
}
/**
* Get a MediaTransformOutput object representing the transformed output. Does the
* transform unless $flags contains self::TRANSFORM_LATER.
*
* @param File $image
* @param string $dstPath Filesystem destination path
* @param string $dstUrl Destination URL to use in output HTML
* @param array $params Arbitrary set of parameters validated by $this->validateParam()
* Note: These parameters have *not* gone through $this->normaliseParams()
* @param int $flags A bitfield, may contain self::TRANSFORM_LATER
* @return MediaTransformOutput
*/
abstract function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 );
/**
* Get the thumbnail extension and MIME type for a given source MIME type
*
* @param string $ext Extension of original file
* @param string $mime MIME type of original file
* @param array|null $params Handler specific rendering parameters
* @return array Thumbnail extension and MIME type
*/
function getThumbType( $ext, $mime, $params = null ) {
$magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
if ( !$ext || $magic->isMatchingExtension( $ext, $mime ) === false ) {
// The extension is not valid for this MIME type and we do
// recognize the MIME type
$extensions = $magic->getExtensionsForType( $mime );
if ( $extensions ) {
return [ strtok( $extensions, ' ' ), $mime ];
}
}
// The extension is correct (true) or the MIME type is unknown to
// MediaWiki (null)
return [ $ext, $mime ];
}
/**
* True if the handled types can be transformed
*
* @param File $file
* @return bool
*/
public function canRender( $file ) {
return true;
}
/**
* True if handled types cannot be displayed directly in a browser
* but can be rendered
*
* @param File $file
* @return bool
*/
public function mustRender( $file ) {
return false;
}
/**
* True if the type has multi-page capabilities
*
* @param File $file
* @return bool
*/
public function isMultiPage( $file ) {
return false;
}
/**
* Page count for a multi-page document, false if unsupported or unknown
*
* @param File $file
* @return bool
*/
function pageCount( File $file ) {
return false;
}
/**
* The material is vectorized and thus scaling is lossless
*
* @param File $file
* @return bool
*/
function isVectorized( $file ) {
return false;
}
/**
* The material is an image, and is animated.
* In particular, video material need not return true.
* @note Before 1.20, this was a method of ImageHandler only
*
* @param File $file
* @return bool
*/
function isAnimatedImage( $file ) {
return false;
}
/**
* If the material is animated, we can animate the thumbnail
* @since 1.20
*
* @param File $file
* @return bool If material is not animated, handler may return any value.
*/
function canAnimateThumbnail( $file ) {
return true;
}
/**
* False if the handler is disabled for all files
* @return bool
*/
function isEnabled() {
return true;
}
/**
* Get an associative array of page dimensions
* Currently "width" and "height" are understood, but this might be
* expanded in the future.
* Returns false if unknown.
*
* It is expected that handlers for paged media (e.g. DjVuHandler)
* will override this method so that it gives the correct results
* for each specific page of the file, using the $page argument.
*
* @note For non-paged media, use getImageSize.
*
* @param File $image
* @param int $page What page to get dimensions of
* @return array|bool
*/
function getPageDimensions( File $image, $page ) {
$gis = $this->getImageSize( $image, $image->getLocalRefPath() );
if ( $gis ) {
return [
'width' => $gis[0],
'height' => $gis[1]
];
} else {
return false;
}
}
/**
* Generic getter for text layer.
* Currently overloaded by PDF and DjVu handlers
* @param File $image
* @param int $page Page number to get information for
* @return bool|string Page text or false when no text found or if
* unsupported.
*/
function getPageText( File $image, $page ) {
return false;
}
/**
* Get the text of the entire document.
* @param File $file
* @return bool|string The text of the document or false if unsupported.
*/
public function getEntireText( File $file ) {
$numPages = $file->pageCount();
if ( !$numPages ) {
// Not a multipage document
return $this->getPageText( $file, 1 );
}
$document = '';
for ( $i = 1; $i <= $numPages; $i++ ) {
$curPage = $this->getPageText( $file, $i );
if ( is_string( $curPage ) ) {
$document .= $curPage . "\n";
}
}
if ( $document !== '' ) {
return $document;
}
return false;
}
/**
* Get an array structure that looks like this:
*
* [
* 'visible' => [
* 'Human-readable name' => 'Human readable value',
* ...
* ],
* 'collapsed' => [
* 'Human-readable name' => 'Human readable value',
* ...
* ]
* ]
* The UI will format this into a table where the visible fields are always
* visible, and the collapsed fields are optionally visible.
*
* The function should return false if there is no metadata to display.
*/
/**
* @todo FIXME: This interface is not very flexible. The media handler
* should generate HTML instead. It can do all the formatting according
* to some standard. That makes it possible to do things like visual
* indication of grouped and chained streams in ogg container files.
* @param File $image
* @param bool|IContextSource $context Context to use (optional)
* @return array|bool
*/
function formatMetadata( $image, $context = false ) {
return false;
}
/** sorts the visible/invisible field.
* Split off from ImageHandler::formatMetadata, as used by more than
* one type of handler.
*
* This is used by the media handlers that use the FormatMetadata class
*
* @param array $metadataArray
* @param bool|IContextSource $context Context to use (optional)
* @return array Array for use displaying metadata.
*/
function formatMetadataHelper( $metadataArray, $context = false ) {
$result = [
'visible' => [],
'collapsed' => []
];
$formatted = FormatMetadata::getFormattedData( $metadataArray, $context );
// Sort fields into visible and collapsed
$visibleFields = $this->visibleMetadataFields();
foreach ( $formatted as $name => $value ) {
$tag = strtolower( $name );
self::addMeta( $result,
in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
'exif',
$tag,
$value
);
}
return $result;
}
/**
* Get a list of metadata items which should be displayed when
* the metadata table is collapsed.
*
* @return array Array of strings
*/
protected function visibleMetadataFields() {
return FormatMetadata::getVisibleFields();
}
/**
* This is used to generate an array element for each metadata value
* That array is then used to generate the table of metadata values
* on the image page
*
* @param array &$array An array containing elements for each type of visibility
* and each of those elements being an array of metadata items. This function adds
* a value to that array.
* @param string $visibility ('visible' or 'collapsed') if this value is hidden
* by default.
* @param string $type Type of metadata tag (currently always 'exif')
* @param string $id The name of the metadata tag (like 'artist' for example).
* its name in the table displayed is the message "$type-$id" (Ex exif-artist ).
* @param string $value Thingy goes into a wikitext table; it used to be escaped but
* that was incompatible with previous practise of customized display
* with wikitext formatting via messages such as 'exif-model-value'.
* So the escaping is taken back out, but generally this seems a confusing
* interface.
* @param bool|string $param Value to pass to the message for the name of the field
* as $1. Currently this parameter doesn't seem to ever be used.
*
* Note, everything here is passed through the parser later on (!)
*/
protected static function addMeta( &$array, $visibility, $type, $id, $value, $param = false ) {
$msg = wfMessage( "$type-$id", $param );
if ( $msg->exists() ) {
$name = $msg->text();
} else {
// This is for future compatibility when using instant commons.
// So as to not display as ugly a name if a new metadata
// property is defined that we don't know about
// (not a major issue since such a property would be collapsed
// by default).
wfDebug( __METHOD__ . ' Unknown metadata name: ' . $id . "\n" );
$name = wfEscapeWikiText( $id );
}
$array[$visibility][] = [
'id' => "$type-$id",
'name' => $name,
'value' => $value
];
}
/**
* Short description. Shown on Special:Search results.
*
* @param File $file
* @return string
*/
function getShortDesc( $file ) {
return self::getGeneralShortDesc( $file );
}
/**
* Long description. Shown under image on image description page surounded by ().
*
* @param File $file
* @return string
*/
function getLongDesc( $file ) {
return self::getGeneralLongDesc( $file );
}
/**
* Used instead of getShortDesc if there is no handler registered for file.
*
* @param File $file
* @return string
*/
static function getGeneralShortDesc( $file ) {
global $wgLang;
return htmlspecialchars( $wgLang->formatSize( $file->getSize() ) );
}
/**
* Used instead of getLongDesc if there is no handler registered for file.
*
* @param File $file
* @return string
*/
static function getGeneralLongDesc( $file ) {
return wfMessage( 'file-info' )->sizeParams( $file->getSize() )
->params( '<span class="mime-type">' . $file->getMimeType() . '</span>' )->parse();
}
/**
* Calculate the largest thumbnail width for a given original file size
* such that the thumbnail's height is at most $maxHeight.
* @param int $boxWidth Width of the thumbnail box.
* @param int $boxHeight Height of the thumbnail box.
* @param int $maxHeight Maximum height expected for the thumbnail.
* @return int
*/
public static function fitBoxWidth( $boxWidth, $boxHeight, $maxHeight ) {
$idealWidth = $boxWidth * $maxHeight / $boxHeight;
$roundedUp = ceil( $idealWidth );
if ( round( $roundedUp * $boxHeight / $boxWidth ) > $maxHeight ) {
return floor( $idealWidth );
} else {
return $roundedUp;
}
}
/**
* Shown in file history box on image description page.
*
* @param File $file
* @return string Dimensions
*/
function getDimensionsString( $file ) {
return '';
}
/**
* Modify the parser object post-transform.
*
* This is often used to do $parser->addOutputHook(),
* in order to add some javascript to render a viewer.
* See TimedMediaHandler or OggHandler for an example.
*
* @param Parser $parser
* @param File $file
*/
function parserTransformHook( $parser, $file ) {
}
/**
* File validation hook called on upload.
*
* If the file at the given local path is not valid, or its MIME type does not
* match the handler class, a Status object should be returned containing
* relevant errors.
*
* @param string $fileName The local path to the file.
* @return Status
*/
function verifyUpload( $fileName ) {
return Status::newGood();
}
/**
* Check for zero-sized thumbnails. These can be generated when
* no disk space is available or some other error occurs
*
* @param string $dstPath The location of the suspect file
* @param int $retval Return value of some shell process, file will be deleted if this is non-zero
* @return bool True if removed, false otherwise
*/
function removeBadFile( $dstPath, $retval = 0 ) {
if ( file_exists( $dstPath ) ) {
$thumbstat = stat( $dstPath );
if ( $thumbstat['size'] == 0 || $retval != 0 ) {
$result = unlink( $dstPath );
if ( $result ) {
wfDebugLog( 'thumbnail',
sprintf( 'Removing bad %d-byte thumbnail "%s". unlink() succeeded',
$thumbstat['size'], $dstPath ) );
} else {
wfDebugLog( 'thumbnail',
sprintf( 'Removing bad %d-byte thumbnail "%s". unlink() failed',
$thumbstat['size'], $dstPath ) );
}
return true;
}
}
return false;
}
/**
* Remove files from the purge list.
*
* This is used by some video handlers to prevent ?action=purge
* from removing a transcoded video, which is expensive to
* regenerate.
*
* @see LocalFile::purgeThumbnails
*
* @param array &$files
* @param array $options Purge options. Currently will always be
* an array with a single key 'forThumbRefresh' set to true.
*/
public function filterThumbnailPurgeList( &$files, $options ) {
// Do nothing
}
/**
* True if the handler can rotate the media
* @since 1.24 non-static. From 1.21-1.23 was static
* @return bool
*/
public function canRotate() {
return false;
}
/**
* On supporting image formats, try to read out the low-level orientation
* of the file and return the angle that the file needs to be rotated to
* be viewed.
*
* This information is only useful when manipulating the original file;
* the width and height we normally work with is logical, and will match
* any produced output views.
*
* For files we don't know, we return 0.
*
* @param File $file
* @return int 0, 90, 180 or 270
*/
public function getRotation( $file ) {
return 0;
}
/**
* Log an error that occurred in an external process
*
* Moved from BitmapHandler to MediaHandler with MediaWiki 1.23
*
* @since 1.23
* @param int $retval
* @param string $err Error reported by command. Anything longer than
* MediaHandler::MAX_ERR_LOG_SIZE is stripped off.
* @param string $cmd
*/
protected function logErrorForExternalProcess( $retval, $err, $cmd ) {
# Keep error output limited (T59985)
$errMessage = trim( substr( $err, 0, self::MAX_ERR_LOG_SIZE ) );
wfDebugLog( 'thumbnail',
sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
wfHostname(), $retval, $errMessage, $cmd ) );
}
/**
* Get list of languages file can be viewed in.
*
* @param File $file
* @return string[] Array of language codes, or empty array if unsupported.
* @since 1.23
*/
public function getAvailableLanguages( File $file ) {
return [];
}
/**
* When overridden in a descendant class, returns a language code most suiting
*
* @since 1.32
*
* @param string $userPreferredLanguage Language code requesed
* @param string[] $availableLanguages Languages present in the file
* @return string|null Language code picked or null if not supported/available
*/
public function getMatchedLanguage( $userPreferredLanguage, array $availableLanguages ) {
return null;
}
/**
* On file types that support renderings in multiple languages,
* which language is used by default if unspecified.
*
* If getAvailableLanguages returns a non-empty array, this must return
* a valid language code. Otherwise can return null if files of this
* type do not support alternative language renderings.
*
* @param File $file
* @return string|null Language code or null if multi-language not supported for filetype.
* @since 1.23
*/
public function getDefaultRenderLanguage( File $file ) {
return null;
}
/**
* If its an audio file, return the length of the file. Otherwise 0.
*
* File::getLength() existed for a long time, but was calling a method
* that only existed in some subclasses of this class (The TMH ones).
*
* @param File $file
* @return float Length in seconds
* @since 1.23
*/
public function getLength( $file ) {
return 0.0;
}
/**
* True if creating thumbnails from the file is large or otherwise resource-intensive.
* @param File $file
* @return bool
*/
public function isExpensiveToThumbnail( $file ) {
return false;
}
/**
* Returns whether or not this handler supports the chained generation of thumbnails according
* to buckets
* @return bool
* @since 1.24
*/
public function supportsBucketing() {
return false;
}
/**
* Returns a normalised params array for which parameters have been cleaned up for bucketing
* purposes
* @param array $params
* @return array
*/
public function sanitizeParamsForBucketing( $params ) {
return $params;
}
/**
* Gets configuration for the file warning message. Return value of
* the following structure:
* [
* // Required, module with messages loaded for the client
* 'module' => 'example.filewarning.messages',
* // Required, array of names of messages
* 'messages' => [
* // Required, main warning message
* 'main' => 'example-filewarning-main',
* // Optional, header for warning dialog
* 'header' => 'example-filewarning-header',
* // Optional, footer for warning dialog
* 'footer' => 'example-filewarning-footer',
* // Optional, text for more-information link (see below)
* 'info' => 'example-filewarning-info',
* ],
* // Optional, link for more information
* 'link' => 'http://example.com',
* ]
*
* Returns null if no warning is necessary.
* @param File $file
* @return array|null
*/
public function getWarningConfig( $file ) {
return null;
}
/**
* Converts a dimensions array about a potentially multipage document from an
* exhaustive list of ordered page numbers to a list of page ranges
* @param Array $pagesByDimensions
* @return String
* @since 1.30
*/
public static function getPageRangesByDimensions( $pagesByDimensions ) {
$pageRangesByDimensions = [];
foreach ( $pagesByDimensions as $dimensions => $pageList ) {
$ranges = [];
$firstPage = $pageList[0];
$lastPage = $firstPage - 1;
foreach ( $pageList as $page ) {
if ( $page > $lastPage + 1 ) {
if ( $firstPage != $lastPage ) {
$ranges[] = "$firstPage-$lastPage";
} else {
$ranges[] = "$firstPage";
}
$firstPage = $page;
}
$lastPage = $page;
}
if ( $firstPage != $lastPage ) {
$ranges[] = "$firstPage-$lastPage";
} else {
$ranges[] = "$firstPage";
}
$pageRangesByDimensions[ $dimensions ] = $ranges;
}
$dimensionsString = [];
foreach ( $pageRangesByDimensions as $dimensions => $pageRanges ) {
$dimensionsString[] = "$dimensions:" . implode( ',', $pageRanges );
}
return implode( '/', $dimensionsString );
}
/**
* Get useful response headers for GET/HEAD requests for a file with the given metadata
* @param array $metadata Contains this handler's unserialized getMetadata() for a file
* @return array
* @since 1.30
*/
public function getContentHeaders( $metadata ) {
return [ 'X-Content-Dimensions' => '' ]; // T175689
}
}
Mini Shell