wiki.techinc.nl/includes/media/ImageHandler.php
Tim Starling b4849e03b7 Use the unserialized form of image metadata internally
Image metadata is usually a serialized string representing an array.
Passing the string around internally and having everything unserialize
it is an awkward convention.

Also, many image handlers were reading the file twice: once for
getMetadata() and again for getImageSize(). Often getMetadata()
would actually read the width and height and then throw it away.

So, in filerepo:

* Add File::getMetadataItem(), which promises to allow partial
  loading of metadata per my proposal on T275268 in a future commit.
* Add File::getMetadataArray(), which returns the unserialized array.
  Some file handlers were returning non-serializable strings from
  getMetadata(), so I gave them a legacy array form ['_error' => ...]
* Changed MWFileProps to return the array form of metadata.
* Deprecate the weird File::getImageSize(). It was apparently not
  called by anything, but was overridden by UnregisteredLocalFile.
* Wrap serialize/unserialize with File::getMetadataForDb() and
  File::loadMetadataFromDb() in preparation for T275268.

In MediaHandler:

* Merged MediaHandler::getImageSize() and MediaHandler::getMetadata()
  into getSizeAndMetadata(). Deprecated the old methods.
* Instead of isMetadataValid() we now have isFileMetadataValid(), which
  only gets a File object, so it can decide what data it needs to load.
* Simplified getPageDimensions() by having it return false for non-paged
  media. It was not called in that case, but was implemented anyway.

In specific handlers:

* Rename DjVuHandler::getUnserializedMetadata() and
  extractTreesFromMetadata() for clarity. "Metadata" in these function
  names meant an XML string.
* Updated DjVuImage::getImageSize() to provide image sizes in the new
  style.
* In ExifBitmapHandler, getRotationForExif() now takes just the
  Orientation tag, rather than a serialized string. Also renamed for
  clarity.
* In GIFMetadataExtractor, return the width, height and bits per channel
  instead of throwing them away. There was some conflation in
  decodeBPP() which I picked apart. Refer to GIF89a section 18.
* In JpegMetadataExtractor, process the SOF0/SOF2 segment to extract
  bits per channel, width, height and components (channel count). This
  is essentially a port of PHP's getimagesize(), so should be bugwards
  compatible.
* In PNGMetadataExtractor, return the width and height, which were
  previously assigned to unused local variables. I verified the
  implementation by referring to the specification.
* In SvgHandler, retain the version validation from unpackMetadata(),
  but rename the function since it now takes an array as input.

In tests:

* In ExifBitmapTest, refactored some tests by using a provider.
* In GIFHandlerTest and PNGHandlerTest, I removed the tests in which
  getMetadata() returns null, since it doesn't make sense when ported to
  getMetadataArray(). I added tests for empty arrays instead.
* In tests, I retained serialization of input data since I figure it's
  useful to confirm that existing database rows will continue to be read
  correctly. I removed serialization of expected values, replacing them
  with plain data.
* In tests, I replaced access to private class constants like
  BROKEN_FILE with string literals, since stability is essential. If
  the class constant changes, the test should fail.

Elsewhere:

* In maintenance/refreshImageMetadata.php, I removed the check for
  shrinking image metadata, since it's not easy to implement and is
  not future compatible. Image metadata is expected to shrink in
  future.

Bug: T275268
Change-Id: I039785d5b6439d71dcc21dcb972177dba5c3a67d
2021-06-08 17:04:01 +10:00

340 lines
8.6 KiB
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
*/
/**
* Media handler abstract base class for images
*
* @stable to extend
*
* @ingroup Media
*/
abstract class ImageHandler extends MediaHandler {
/**
* @inheritDoc
* @stable to override
* @param File $file
* @return bool
*/
public function canRender( $file ) {
return ( $file->getWidth() && $file->getHeight() );
}
/**
* @inheritDoc
* @stable to override
* @return string[]
*/
public function getParamMap() {
return [ 'img_width' => 'width' ];
}
/**
* @inheritDoc
* @stable to override
*/
public function validateParam( $name, $value ) {
if ( in_array( $name, [ 'width', 'height' ] ) ) {
if ( $value <= 0 ) {
return false;
} else {
return true;
}
} else {
return false;
}
}
/**
* @inheritDoc
* @stable to override
*/
public function makeParamString( $params ) {
if ( isset( $params['physicalWidth'] ) ) {
$width = $params['physicalWidth'];
} elseif ( isset( $params['width'] ) ) {
$width = $params['width'];
} else {
throw new MediaTransformInvalidParametersException( 'No width specified to ' . __METHOD__ );
}
# Removed for ProofreadPage
# $width = intval( $width );
return "{$width}px";
}
/**
* @inheritDoc
* @stable to override
*/
public function parseParamString( $str ) {
$m = false;
if ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
return [ 'width' => $m[1] ];
} else {
return false;
}
}
/**
* @inheritDoc
* @stable to override
*/
protected function getScriptParams( $params ) {
return [ 'width' => $params['width'] ];
}
/**
* @inheritDoc
* @stable to override
* @param File $image
* @param array &$params
* @return bool
*/
public function normaliseParams( $image, &$params ) {
$mimeType = $image->getMimeType();
if ( !isset( $params['width'] ) ) {
return false;
}
if ( !isset( $params['page'] ) ) {
$params['page'] = 1;
} else {
$params['page'] = intval( $params['page'] );
if ( $params['page'] > $image->pageCount() ) {
$params['page'] = $image->pageCount();
}
if ( $params['page'] < 1 ) {
$params['page'] = 1;
}
}
$srcWidth = $image->getWidth( $params['page'] );
$srcHeight = $image->getHeight( $params['page'] );
if ( isset( $params['height'] ) && $params['height'] != -1 ) {
# Height & width were both set
if ( $params['width'] * $srcHeight > $params['height'] * $srcWidth ) {
# Height is the relative smaller dimension, so scale width accordingly
$params['width'] = self::fitBoxWidth( $srcWidth, $srcHeight, $params['height'] );
if ( $params['width'] == 0 ) {
# Very small image, so we need to rely on client side scaling :(
$params['width'] = 1;
}
$params['physicalWidth'] = $params['width'];
} else {
# Height was crap, unset it so that it will be calculated later
unset( $params['height'] );
}
}
if ( !isset( $params['physicalWidth'] ) ) {
# Passed all validations, so set the physicalWidth
$params['physicalWidth'] = $params['width'];
}
# Because thumbs are only referred to by width, the height always needs
# to be scaled by the width to keep the thumbnail sizes consistent,
# even if it was set inside the if block above
$params['physicalHeight'] = File::scaleHeight( $srcWidth, $srcHeight,
$params['physicalWidth'] );
# Set the height if it was not validated in the if block higher up
if ( !isset( $params['height'] ) || $params['height'] == -1 ) {
$params['height'] = $params['physicalHeight'];
}
if ( !$this->validateThumbParams( $params['physicalWidth'],
$params['physicalHeight'], $srcWidth, $srcHeight, $mimeType )
) {
return false;
}
return true;
}
/**
* Validate thumbnail parameters and fill in the correct height
*
* @param int &$width Specified width (input/output)
* @param int &$height Height (output only)
* @param int $srcWidth Width of the source image
* @param int $srcHeight Height of the source image
* @param string $mimeType Unused
* @return bool False to indicate that an error should be returned to the user.
*/
private function validateThumbParams( &$width, &$height, $srcWidth, $srcHeight, $mimeType ) {
$width = intval( $width );
# Sanity check $width
if ( $width <= 0 ) {
wfDebug( __METHOD__ . ": Invalid destination width: $width" );
return false;
}
if ( $srcWidth <= 0 ) {
wfDebug( __METHOD__ . ": Invalid source width: $srcWidth" );
return false;
}
$height = File::scaleHeight( $srcWidth, $srcHeight, $width );
if ( $height == 0 ) {
# Force height to be at least 1 pixel
$height = 1;
}
return true;
}
/**
* @inheritDoc
* @stable to override
* @param File $image
* @param string $script
* @param array $params
* @return bool|MediaTransformOutput
*/
public function getScriptedTransform( $image, $script, $params ) {
if ( !$this->normaliseParams( $image, $params ) ) {
return false;
}
$url = wfAppendQuery( $script, $this->getScriptParams( $params ) );
if ( $image->mustRender() || $params['width'] < $image->getWidth() ) {
return new ThumbnailImage( $image, $url, false, $params );
}
}
public function getImageSize( $image, $path ) {
Wikimedia\suppressWarnings();
$gis = getimagesize( $path );
Wikimedia\restoreWarnings();
return $gis;
}
public function getSizeAndMetadata( $state, $path ) {
// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
$gis = @getimagesize( $path );
if ( $gis ) {
$info = [
'width' => $gis[0],
'height' => $gis[1],
];
if ( isset( $gis['bits'] ) ) {
$info['bits'] = $gis['bits'];
}
} else {
$info = [];
}
return $info;
}
/**
* Function that returns the number of pixels to be thumbnailed.
* Intended for animated GIFs to multiply by the number of frames.
*
* If the file doesn't support a notion of "area" return 0.
* @stable to override
*
* @param File $image
* @return int
*/
public function getImageArea( $image ) {
return $image->getWidth() * $image->getHeight();
}
/**
* @inheritDoc
* @stable to override
* @param File $file
* @return string
*/
public function getShortDesc( $file ) {
global $wgLang;
$nbytes = htmlspecialchars( $wgLang->formatSize( $file->getSize() ) );
$widthheight = wfMessage( 'widthheight' )
->numParams( $file->getWidth(), $file->getHeight() )->escaped();
return "$widthheight ($nbytes)";
}
/**
* @inheritDoc
* @stable to override
* @param File $file
* @return string
*/
public function getLongDesc( $file ) {
global $wgLang;
$pages = $file->pageCount();
$size = htmlspecialchars( $wgLang->formatSize( $file->getSize() ) );
if ( $pages === false || $pages <= 1 ) {
$msg = wfMessage( 'file-info-size' )->numParams( $file->getWidth(),
$file->getHeight() )->params( $size,
'<span class="mime-type">' . $file->getMimeType() . '</span>' )->parse();
} else {
$msg = wfMessage( 'file-info-size-pages' )->numParams( $file->getWidth(),
$file->getHeight() )->params( $size,
'<span class="mime-type">' . $file->getMimeType() . '</span>' )->numParams( $pages )->parse();
}
return $msg;
}
/**
* @inheritDoc
* @stable to override
* @param File $file
* @return string
*/
public function getDimensionsString( $file ) {
$pages = $file->pageCount();
if ( $pages > 1 ) {
return wfMessage( 'widthheightpage' )
->numParams( $file->getWidth(), $file->getHeight(), $pages )->text();
} else {
return wfMessage( 'widthheight' )
->numParams( $file->getWidth(), $file->getHeight() )->text();
}
}
/**
* @inheritDoc
* @stable to override
*/
public function sanitizeParamsForBucketing( $params ) {
$params = parent::sanitizeParamsForBucketing( $params );
// We unset the height parameters in order to let normaliseParams recalculate them
// Otherwise there might be a height discrepancy
unset( $params['height'] );
unset( $params['physicalHeight'] );
return $params;
}
}