Dave Jarvis' Repositories
git clone https://repo.autonoma.ca/repo/keenwrite.git
Move image caching into factory chain
| Author | DaveJarvis <email> |
|---|---|
| Date | 2020-12-29 15:44:09 GMT-0800 |
| Commit | a4b139829033a9ccedf3e3074840194879c77625 |
| Parent | 343c019 |
| Delta | 77 lines added, 103 lines removed, 26-line decrease |
src/main/java/com/keenwrite/preview/ChainedReplacedElementFactory.java
| import com.keenwrite.ui.adapters.ReplacedElementAdapter; | ||
| +import com.keenwrite.util.BoundedCache; | ||
| import org.w3c.dom.Element; | ||
| import org.xhtmlrenderer.extend.ReplacedElement; | ||
| import org.xhtmlrenderer.extend.ReplacedElementFactory; | ||
| import org.xhtmlrenderer.extend.UserAgentCallback; | ||
| import org.xhtmlrenderer.layout.LayoutContext; | ||
| import org.xhtmlrenderer.render.BlockBox; | ||
| import java.util.LinkedHashSet; | ||
| +import java.util.Map; | ||
| import java.util.Set; | ||
| + | ||
| +import static com.keenwrite.preview.SvgReplacedElementFactory.HTML_IMAGE; | ||
| +import static com.keenwrite.preview.SvgReplacedElementFactory.HTML_IMAGE_SRC; | ||
| +import static com.keenwrite.processors.markdown.tex.TexNode.HTML_TEX; | ||
| /** | ||
 | ||
| */ | ||
| private final Set<ReplacedElementFactory> mFactories = new LinkedHashSet<>(); | ||
| + | ||
| + /** | ||
| + * A bounded cache that removes the oldest image if the maximum number of | ||
| + * cached images has been reached. This constrains the number of images | ||
| + * loaded into memory. | ||
| + */ | ||
| + private final Map<String, ReplacedElement> mCache = new BoundedCache<>( 150 ); | ||
| @Override | ||
| public ReplacedElement createReplacedElement( | ||
| final LayoutContext c, | ||
| final BlockBox box, | ||
| final UserAgentCallback uac, | ||
| final int width, | ||
| final int height ) { | ||
| - for( final var factory : mFactories ) { | ||
| - var replacement = | ||
| - factory.createReplacedElement( c, box, uac, width, height ); | ||
| + for( final var f : mFactories ) { | ||
| + final var e = box.getElement(); | ||
| - if( replacement != null ) { | ||
| - return replacement; | ||
| + // Exit early for super-speed. | ||
| + if( e == null ) { | ||
| + break; | ||
| + } | ||
| + | ||
| + // If the source image is cached, don't bother fetching. This optimization | ||
| + // avoids making multiple HTTP requests for the same URI. | ||
| + final var node = e.getNodeName(); | ||
| + final var source = switch( node ) { | ||
| + case HTML_IMAGE -> e.getAttribute( HTML_IMAGE_SRC ); | ||
| + case HTML_TEX -> e.getTextContent(); | ||
| + default -> ""; | ||
| + }; | ||
| + | ||
| + // HTML <img> or <tex> elements without source data shall not pass. | ||
| + if( source.isBlank() ) { | ||
| + break; | ||
| + } | ||
| + | ||
| + final var replaced = mCache.computeIfAbsent( | ||
| + source, k -> f.createReplacedElement( c, box, uac, width, height ) | ||
| + ); | ||
| + | ||
| + if( replaced != null ) { | ||
| + return replaced; | ||
| } | ||
| } | ||
src/main/java/com/keenwrite/preview/SvgReplacedElementFactory.java
| import com.keenwrite.io.HttpMediaType; | ||
| import com.keenwrite.io.MediaType; | ||
| -import com.keenwrite.util.BoundedCache; | ||
| +import com.keenwrite.ui.adapters.ReplacedElementAdapter; | ||
| import org.w3c.dom.Element; | ||
| import org.xhtmlrenderer.extend.ReplacedElement; | ||
| -import org.xhtmlrenderer.extend.ReplacedElementFactory; | ||
| import org.xhtmlrenderer.extend.UserAgentCallback; | ||
| import org.xhtmlrenderer.layout.LayoutContext; | ||
| import org.xhtmlrenderer.render.BlockBox; | ||
| -import org.xhtmlrenderer.simple.extend.FormSubmissionListener; | ||
| import org.xhtmlrenderer.swing.ImageReplacedElement; | ||
| import java.awt.image.BufferedImage; | ||
| import java.net.URI; | ||
| import java.nio.file.Paths; | ||
| -import java.util.Map; | ||
| -import java.util.Optional; | ||
| import static com.keenwrite.StatusBarNotifier.clue; | ||
| ||
| * a document to transform them into rasterized versions. | ||
| */ | ||
| -public class SvgReplacedElementFactory implements ReplacedElementFactory { | ||
| +public class SvgReplacedElementFactory extends ReplacedElementAdapter { | ||
| /** | ||
| ||
| } | ||
| - private static final String HTML_IMAGE = "img"; | ||
| - private static final String HTML_IMAGE_SRC = "src"; | ||
| + public static final String HTML_IMAGE = "img"; | ||
| + public static final String HTML_IMAGE_SRC = "src"; | ||
| private static final ImageReplacedElement BROKEN_IMAGE = | ||
| createImageReplacedElement( BROKEN_IMAGE_PLACEHOLDER ); | ||
| - | ||
| - /** | ||
| - * A bounded cache that removes the oldest image if the maximum number of | ||
| - * cached images has been reached. This constrains the number of images | ||
| - * loaded into memory. | ||
| - */ | ||
| - private final Map<String, ImageReplacedElement> mImageCache = | ||
| - new BoundedCache<>( 150 ); | ||
| @Override | ||
| public ReplacedElement createReplacedElement( | ||
| final LayoutContext c, | ||
| final BlockBox box, | ||
| final UserAgentCallback uac, | ||
| final int cssWidth, | ||
| final int cssHeight ) { | ||
| final var e = box.getElement(); | ||
| - | ||
| - // Exit early for the speeds. | ||
| - if( e == null ) { | ||
| - return null; | ||
| - } | ||
| - | ||
| - // If the source image is cached, don't bother fetching. This optimization | ||
| - // avoids making multiple HTTP requests for the same URI. | ||
| - final var node = e.getNodeName(); | ||
| - final var source = switch( node ) { | ||
| - case HTML_IMAGE -> e.getAttribute( HTML_IMAGE_SRC ); | ||
| - case HTML_TEX -> e.getTextContent(); | ||
| - default -> ""; | ||
| - }; | ||
| - | ||
| - // Non-image HTML elements shall not pass. | ||
| - if( source.isBlank() ) { | ||
| - return null; | ||
| - } | ||
| - final var image = new ImageReplacedElement[ 1 ]; | ||
| - getCachedImage( source ).ifPresentOrElse( | ||
| - ( i ) -> image[ 0 ] = i, | ||
| - () -> { | ||
| - try { | ||
| - BufferedImage raster = null; | ||
| + ImageReplacedElement image = null; | ||
| - switch( node ) { | ||
| - case HTML_IMAGE -> { | ||
| - URI uri = null; | ||
| + try { | ||
| + BufferedImage raster = null; | ||
| - if( getProtocol( source ).isHttp() ) { | ||
| - var mediaType = MediaType.valueFrom( source ); | ||
| + switch( e.getNodeName() ) { | ||
| + case HTML_IMAGE -> { | ||
| + final var source = e.getAttribute( HTML_IMAGE_SRC ); | ||
| + URI uri = null; | ||
| - if( isSvg( mediaType ) || mediaType == UNDEFINED ) { | ||
| - // Attempt to rasterize SVG depending on URL resource content. | ||
| - uri = new URI( source ); | ||
| + if( getProtocol( source ).isHttp() ) { | ||
| + var mediaType = MediaType.valueFrom( source ); | ||
| - // Attempt rasterization for SVG or plain text formats. | ||
| - if( !isSvg( HttpMediaType.valueFrom( uri ) ) ) { | ||
| - uri = null; | ||
| - } | ||
| - } | ||
| - } | ||
| - else if( isSvg( MediaType.valueFrom( source ) ) ) { | ||
| - // Attempt to rasterize based on file name. | ||
| - final var base = new URI( getBaseUri( e ) ).getPath(); | ||
| - uri = Paths.get( base, source ).toUri(); | ||
| - } | ||
| + if( isSvg( mediaType ) || mediaType == UNDEFINED ) { | ||
| + uri = new URI( source ); | ||
| - if( uri != null ) { | ||
| - raster = rasterize( uri, box.getContentWidth() ); | ||
| + // Attempt to rasterize SVG depending on URL resource content. | ||
| + if( !isSvg( HttpMediaType.valueFrom( uri ) ) ) { | ||
| + uri = null; | ||
| } | ||
| } | ||
| - case HTML_TEX -> | ||
| - // Convert the TeX element to a raster graphic. | ||
| - raster = rasterize( getInstance().render( source ) ); | ||
| + } | ||
| + else if( isSvg( MediaType.valueFrom( source ) ) ) { | ||
| + // Attempt to rasterize based on file name. | ||
| + final var base = new URI( getBaseUri( e ) ).getPath(); | ||
| + uri = Paths.get( base, source ).toUri(); | ||
| } | ||
| - if( raster != null ) { | ||
| - image[ 0 ] = putCachedImage( source, raster ); | ||
| + if( uri != null ) { | ||
| + raster = rasterize( uri, box.getContentWidth() ); | ||
| } | ||
| - } catch( final Exception ex ) { | ||
| - image[ 0 ] = BROKEN_IMAGE; | ||
| - clue( ex ); | ||
| } | ||
| + case HTML_TEX -> | ||
| + // Convert the TeX element to a raster graphic. | ||
| + raster = rasterize( getInstance().render( e.getTextContent() ) ); | ||
| } | ||
| - ); | ||
| - return image[ 0 ]; | ||
| + if( raster != null ) { | ||
| + image = createImageReplacedElement( raster ); | ||
| + } | ||
| + } catch( final Exception ex ) { | ||
| + image = BROKEN_IMAGE; | ||
| + clue( ex ); | ||
| + } | ||
| + | ||
| + return image; | ||
| } | ||
| ||
| return ""; | ||
| - } | ||
| - | ||
| - @Override | ||
| - public void reset() { | ||
| - } | ||
| - | ||
| - @Override | ||
| - public void remove( final Element e ) { | ||
| - } | ||
| - | ||
| - @Override | ||
| - public void setFormSubmissionListener( FormSubmissionListener listener ) { | ||
| - } | ||
| - | ||
| - private ImageReplacedElement putCachedImage( | ||
| - final String source, final BufferedImage image ) { | ||
| - assert source != null; | ||
| - assert image != null; | ||
| - | ||
| - final var result = createImageReplacedElement( image ); | ||
| - mImageCache.put( source, result ); | ||
| - return result; | ||
| - } | ||
| - | ||
| - private Optional<ImageReplacedElement> getCachedImage( final String source ) { | ||
| - return Optional.ofNullable( mImageCache.get( source ) ); | ||
| } | ||