mediawiki-extensions-PdfHan.../includes/PdfHandler.php
Tim Starling 989b42b8eb Use the new metadata splitting facility to improve PDF performance
* Migrate to the new metadata system: override getSizeAndMetadata()
* Use getHandlerState() instead of a custom property on the File object.
* Opt in to metadata splitting. Avoid loading the text item unless it is
  really needed.
* In getDimensionInfo(), use getHandlerState() instead of the
  WANObjectCache process cache (pcTTL). This is just a
  micro-optimisation, informed by profiling, which showed 90 calls to
  this function during an image page view.

Depends-On: I876ea5c9d3a1881e278f689d2f8a3ae20240c703
Change-Id: I30d0b0009fcb11c14d14663bd1f2c2a3dfac55d6
2021-06-11 15:56:57 +10:00

464 lines
12 KiB
PHP

<?php
namespace MediaWiki\Extension\PdfHandler;
use File;
use IContextSource;
use ImageHandler;
use MediaTransformError;
use MediaTransformOutput;
use MediaWiki\MediaWikiServices;
use PoolCounterWorkViaCallback;
use ResourceLoader;
use ThumbnailImage;
use TransformParameterError;
/**
* Copyright © 2007 Martin Seidel (Xarax) <jodeldi@gmx.de>
*
* Inspired by djvuhandler from Tim Starling
* Modified and written by Xarax
*
* 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
*/
class PdfHandler extends ImageHandler {
private const MESSAGES = [
'main' => 'pdf-file-page-warning',
'header' => 'pdf-file-page-warning-header',
'info' => 'pdf-file-page-warning-info',
'footer' => 'pdf-file-page-warning-footer',
];
/**
* 10MB is considered a large file
*/
private const LARGE_FILE = 1e7;
/**
* Key for getHandlerState for value of type PdfImage
*/
private const STATE_PDF_IMAGE = 'pdfImage';
/**
* Key for getHandlerState for dimension info
*/
private const STATE_DIMENSION_INFO = 'pdfDimensionInfo';
/**
* @return bool
*/
public function isEnabled() {
global $wgPdfProcessor, $wgPdfPostProcessor, $wgPdfInfo;
if ( !isset( $wgPdfProcessor ) || !isset( $wgPdfPostProcessor ) || !isset( $wgPdfInfo ) ) {
wfDebug( "PdfHandler is disabled, please set the following\n" );
wfDebug( "variables in LocalSettings.php:\n" );
wfDebug( "\$wgPdfProcessor, \$wgPdfPostProcessor, \$wgPdfInfo\n" );
return false;
}
return true;
}
/**
* @param File $file
* @return bool
*/
public function mustRender( $file ) {
return true;
}
/**
* @param File $file
* @return bool
*/
public function isMultiPage( $file ) {
return true;
}
/**
* @param string $name
* @param string $value
* @return bool
*/
public function validateParam( $name, $value ) {
if ( $name === 'page' && trim( $value ) !== (string)intval( $value ) ) {
// Extra junk on the end of page, probably actually a caption
// e.g. [[File:Foo.pdf|thumb|Page 3 of the document shows foo]]
return false;
}
if ( in_array( $name, [ 'width', 'height', 'page' ] ) ) {
return ( $value > 0 );
}
return false;
}
/**
* @param array $params
* @return bool|string
*/
public function makeParamString( $params ) {
$page = $params['page'] ?? 1;
if ( !isset( $params['width'] ) ) {
return false;
}
return "page{$page}-{$params['width']}px";
}
/**
* @param string $str
* @return array|bool
*/
public function parseParamString( $str ) {
$m = [];
if ( preg_match( '/^page(\d+)-(\d+)px$/', $str, $m ) ) {
return [ 'width' => $m[2], 'page' => $m[1] ];
}
return false;
}
/**
* @param array $params
* @return array
*/
public function getScriptParams( $params ) {
return [
'width' => $params['width'],
'page' => $params['page'],
];
}
/**
* @return array
*/
public function getParamMap() {
return [
'img_width' => 'width',
'img_page' => 'page',
];
}
/**
* @param int $width
* @param int $height
* @param string $msg
* @return MediaTransformError
*/
protected function doThumbError( $width, $height, $msg ) {
return new MediaTransformError( 'thumbnail_error',
$width, $height, wfMessage( $msg )->inContentLanguage()->text() );
}
/**
* @param File $image
* @param string $dstPath
* @param string $dstUrl
* @param array $params
* @param int $flags
* @return MediaTransformError|MediaTransformOutput|ThumbnailImage|TransformParameterError
*/
public function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
global $wgPdfProcessor, $wgPdfPostProcessor, $wgPdfHandlerDpi, $wgPdfHandlerJpegQuality;
if ( !$this->normaliseParams( $image, $params ) ) {
return new TransformParameterError( $params );
}
// @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset
$width = (int)$params['width'];
$height = (int)$params['height'];
$page = (int)$params['page'];
if ( $page > $this->pageCount( $image ) ) {
return $this->doThumbError( $width, $height, 'pdf_page_error' );
}
if ( $flags & self::TRANSFORM_LATER ) {
return new ThumbnailImage( $image, $dstUrl, false, [
'width' => $width,
'height' => $height,
'page' => $page,
] );
}
if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
return $this->doThumbError( $width, $height, 'thumbnail_dest_directory' );
}
// Thumbnail extraction is very inefficient for large files.
// Provide a way to pool count limit the number of downloaders.
if ( $image->getSize() >= self::LARGE_FILE ) {
$work = new PoolCounterWorkViaCallback( 'GetLocalFileCopy', sha1( $image->getName() ),
[
'doWork' => static function () use ( $image ) {
return $image->getLocalRefPath();
}
]
);
$srcPath = $work->execute();
} else {
$srcPath = $image->getLocalRefPath();
}
if ( $srcPath === false ) {
// could not download original
return $this->doThumbError( $width, $height, 'filemissing' );
}
$cmd = '(' . wfEscapeShellArg(
$wgPdfProcessor,
"-sDEVICE=jpeg",
"-sOutputFile=-",
"-sstdout=%stderr",
"-dFirstPage={$page}",
"-dLastPage={$page}",
"-dSAFER",
"-r{$wgPdfHandlerDpi}",
"-dBATCH",
"-dNOPAUSE",
"-q",
$srcPath
);
$cmd .= " | " . wfEscapeShellArg(
$wgPdfPostProcessor,
"-depth",
"8",
"-quality",
$wgPdfHandlerJpegQuality,
"-resize",
$width,
"-",
$dstPath
);
$cmd .= ")";
wfDebug( __METHOD__ . ": $cmd\n" );
$retval = '';
$err = wfShellExecWithStderr( $cmd, $retval );
$removed = $this->removeBadFile( $dstPath, $retval );
if ( $retval != 0 || $removed ) {
wfDebugLog( 'thumbnail',
sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
wfHostname(), $retval, trim( $err ), $cmd ) );
return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
} else {
return new ThumbnailImage( $image, $dstUrl, $dstPath, [
'width' => $width,
'height' => $height,
'page' => $page,
] );
}
}
/**
* @param \MediaHandlerState $state
* @param string $path
* @return PdfImage
*/
private function getPdfImage( $state, $path ) {
$pdfimg = $state->getHandlerState( self::STATE_PDF_IMAGE );
if ( !$pdfimg ) {
$pdfimg = new PdfImage( $path );
$state->setHandlerState( self::STATE_PDF_IMAGE, $pdfimg );
}
return $pdfimg;
}
/**
* @param \MediaHandlerState $state
* @param string $path
* @return array|bool
*/
public function getSizeAndMetadata( $state, $path ) {
$metadata = $this->getPdfImage( $state, $path )->retrieveMetaData();
$sizes = PdfImage::getPageSize( $metadata, 1 );
if ( $sizes ) {
return $sizes + [ 'metadata' => $metadata ];
} else {
return [ 'metadata' => $metadata ];
}
}
/**
* @param string $ext
* @param string $mime
* @param null $params
* @return array
*/
public function getThumbType( $ext, $mime, $params = null ) {
global $wgPdfOutputExtension;
static $mime;
if ( !isset( $mime ) ) {
$magic = MediaWikiServices::getInstance()->getMimeAnalyzer();
$mime = $magic->guessTypesForExtension( $wgPdfOutputExtension );
}
return [ $wgPdfOutputExtension, $mime ];
}
/**
* @param File $file
* @return bool
*/
public function isFileMetadataValid( $file ) {
$data = $file->getMetadataItems( [ 'mergedMetadata', 'pages' ] );
if ( !isset( $data['pages'] ) ) {
return self::METADATA_BAD;
} elseif ( !isset( $data['mergedMetadata'] ) ) {
return self::METADATA_COMPATIBLE;
}
return self::METADATA_GOOD;
}
/**
* @param File $image
* @param bool|IContextSource $context Context to use (optional)
* @return bool|array
*/
public function formatMetadata( $image, $context = false ) {
$mergedMetadata = $image->getMetadataItem( 'mergedMetadata' );
if ( !is_array( $mergedMetadata ) || !count( $mergedMetadata ) ) {
return false;
}
// Inherited from MediaHandler.
return $this->formatMetadataHelper( $mergedMetadata, $context );
}
/** @inheritDoc */
protected function formatTag( string $key, $vals, $context = false ) {
switch ( $key ) {
case 'pdf-Producer':
case 'pdf-Version':
return htmlspecialchars( $vals );
case 'pdf-PageSize':
foreach ( $vals as &$val ) {
$val = htmlspecialchars( $val );
}
return $vals;
case 'pdf-Encrypted':
// @todo: The value isn't i18n-ised; should be done here.
// For reference, if encrypted this field's value looks like:
// "yes (print:yes copy:no change:no addNotes:no)"
return htmlspecialchars( $vals );
default:
break;
}
// Use default formatting
return false;
}
/**
* @param File $image
* @return bool|int
*/
public function pageCount( File $image ) {
$info = $this->getDimensionInfo( $image );
return $info ? $info['pageCount'] : false;
}
/**
* @param File $image
* @param int $page
* @return array|bool
*/
public function getPageDimensions( File $image, $page ) {
// MW starts pages at 1, as they are stored here
$index = $page;
$info = $this->getDimensionInfo( $image );
if ( $info && isset( $info['dimensionsByPage'][$index] ) ) {
return $info['dimensionsByPage'][$index];
}
return false;
}
protected function getDimensionInfo( File $file ) {
$info = $file->getHandlerState( self::STATE_DIMENSION_INFO );
if ( !$info ) {
$cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
$info = $cache->getWithSetCallback(
$cache->makeKey( 'file-pdf', 'dimensions', $file->getSha1() ),
$cache::TTL_INDEFINITE,
static function () use ( $file ) {
$data = $file->getMetadataItems( PdfImage::ITEMS_FOR_PAGE_SIZE );
if ( !$data || !isset( $data['Pages'] ) ) {
return false;
}
$dimsByPage = [];
$count = intval( $data['Pages'] );
for ( $i = 1; $i <= $count; $i++ ) {
$dimsByPage[$i] = PdfImage::getPageSize( $data, $i );
}
return [ 'pageCount' => $count, 'dimensionsByPage' => $dimsByPage ];
}
);
}
$file->setHandlerState( self::STATE_DIMENSION_INFO, $info );
return $info;
}
/**
* @param File $image
* @param int $page
* @return bool
*/
public function getPageText( File $image, $page ) {
$pageTexts = $image->getMetadataItem( 'text' );
if ( !is_array( $pageTexts ) || !isset( $pageTexts[$page - 1] ) ) {
return false;
}
return $pageTexts[$page - 1];
}
/**
* Adds a warning about PDFs being potentially dangerous to the file
* page. Multiple messages with this base will be used.
* @param File $file
* @return array
*/
public function getWarningConfig( $file ) {
return [
'messages' => self::MESSAGES,
'link' => '//www.mediawiki.org/wiki/Special:MyLanguage/Help:Security/PDF_files',
'module' => 'pdfhandler.messages',
];
}
/**
* Register a module with the warning messages in it.
* @param ResourceLoader &$resourceLoader
*/
public static function registerWarningModule( &$resourceLoader ) {
$resourceLoader->register( 'pdfhandler.messages', [
'messages' => array_values( self::MESSAGES ),
] );
}
public function useSplitMetadata() {
return true;
}
}