only compute rtl once by storing it in the database on fetch

commafeed-server/src/main/java/com/commafeed/backend/feed/FeedUtils.java

@@ -17,7 +17,6 @@ import org.netpreserve.urlcanon.ParsedUrl;
 
 import com.commafeed.backend.feed.FeedEntryKeyword.Mode;
 import com.commafeed.backend.feed.parser.TextDirectionDetector;
-import com.commafeed.backend.model.FeedEntry;
 import com.commafeed.backend.model.FeedSubscription;
 import com.commafeed.frontend.model.Entry;
 
@@ -92,24 +91,18 @@ public class FeedUtils {
 		return normalized;
 	}
 
-	public static boolean isRTL(FeedEntry entry) {
-		String text = entry.getContent().getContent();
-
-		if (StringUtils.isBlank(text)) {
-			text = entry.getContent().getTitle();
-		}
-
+	public static boolean isRTL(String title, String content) {
+		String text = StringUtils.isNotBlank(content) ? content : title;
 		if (StringUtils.isBlank(text)) {
 			return false;
 		}
 
-		text = Jsoup.parse(text).text();
-		if (StringUtils.isBlank(text)) {
+		String stripped = Jsoup.parse(text).text();
+		if (StringUtils.isBlank(stripped)) {
 			return false;
 		}
 
-		TextDirectionDetector.Direction direction = TextDirectionDetector.detect(text);
-		return direction == TextDirectionDetector.Direction.RIGHT_TO_LEFT;
+		return TextDirectionDetector.detect(stripped) == TextDirectionDetector.Direction.RIGHT_TO_LEFT;
 	}
 
 	public static String removeTrailingSlash(String url) {

commafeed-server/src/main/java/com/commafeed/backend/feed/parser/TextDirectionDetector.java

@@ -1,7 +1,6 @@
 package com.commafeed.backend.feed.parser;
 
 import java.text.Bidi;
-import java.util.concurrent.atomic.AtomicLong;
 import java.util.regex.Pattern;
 
 import org.apache.commons.lang3.math.NumberUtils;
@@ -22,8 +21,8 @@ public class TextDirectionDetector {
 			return Direction.LEFT_TO_RIGHT;
 		}
 
-		AtomicLong rtl = new AtomicLong();
-		AtomicLong total = new AtomicLong();
+		long rtl = 0;
+		long total = 0;
 		for (String token : WORDS_PATTERN.split(input)) {
 			// skip urls
 			if (URL_PATTERN.matcher(token).matches()) {
@@ -39,18 +38,18 @@ public class TextDirectionDetector {
 			if (requiresBidi) {
 				Bidi bidi = new Bidi(token, Bidi.DIRECTION_DEFAULT_LEFT_TO_RIGHT);
 				if (bidi.getBaseLevel() == 1) {
-					rtl.incrementAndGet();
+					rtl++;
 				}
 			}
 
-			total.incrementAndGet();
+			total++;
 		}
 
-		if (total.longValue() == 0) {
+		if (total == 0) {
 			return Direction.LEFT_TO_RIGHT;
 		}
 
-		double ratio = rtl.doubleValue() / total.doubleValue();
+		double ratio = (double) rtl / total;
 		return ratio > RTL_THRESHOLD ? Direction.RIGHT_TO_LEFT : Direction.LEFT_TO_RIGHT;
 	}
 

commafeed-server/src/main/java/com/commafeed/backend/model/FeedEntryContent.java

@@ -6,8 +6,12 @@ import java.util.Set;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.hibernate.annotations.JdbcTypeCode;
 
+import com.commafeed.backend.feed.FeedUtils;
+
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
 import jakarta.persistence.Lob;
 import jakarta.persistence.OneToMany;
 import jakarta.persistence.Table;
@@ -21,6 +25,10 @@ import lombok.Setter;
 @Setter
 public class FeedEntryContent extends AbstractModel {
 
+	public enum Direction {
+		ltr, rtl, unknown
+	}
+
 	@Column(length = 2048)
 	private String title;
 
@@ -58,6 +66,10 @@ public class FeedEntryContent extends AbstractModel {
 	@Column(length = 4096)
 	private String categories;
 
+	@Column
+	@Enumerated(EnumType.STRING)
+	private Direction direction = Direction.unknown;
+
 	@OneToMany(mappedBy = "content")
 	private Set<FeedEntry> entries;
 
@@ -79,4 +91,14 @@ public class FeedEntryContent extends AbstractModel {
 				.build();
 	}
 
+	public boolean isRTL() {
+		if (direction == Direction.rtl) {
+			return true;
+		} else if (direction == Direction.ltr) {
+			return false;
+		} else {
+			// detect on the fly for content that was inserted before the direction field was added
+			return FeedUtils.isRTL(title, content);
+		}
+	}
 }

commafeed-server/src/main/java/com/commafeed/backend/service/FeedEntryContentService.java

@@ -47,6 +47,8 @@ public class FeedEntryContentService {
 		entryContent.setContent(cleaningService.clean(content.content(), baseUrl, false));
 		entryContent.setAuthor(FeedUtils.truncate(cleaningService.clean(content.author(), baseUrl, true), 128));
 		entryContent.setCategories(FeedUtils.truncate(content.categories(), 4096));
+		entryContent.setDirection(
+				FeedUtils.isRTL(content.title(), content.content()) ? FeedEntryContent.Direction.rtl : FeedEntryContent.Direction.ltr);
 
 		Enclosure enclosure = content.enclosure();
 		if (enclosure != null) {

commafeed-server/src/main/java/com/commafeed/frontend/model/Entry.java

@@ -128,7 +128,7 @@ public class Entry implements Serializable {
 		entry.setTags(status.getTags().stream().map(FeedEntryTag::getName).toList());
 
 		if (content != null) {
-			entry.setRtl(FeedUtils.isRTL(feedEntry));
+			entry.setRtl(content.isRTL());
 			entry.setTitle(content.getTitle());
 			entry.setContent(proxyImages ? FeedUtils.proxyImages(content.getContent()) : content.getContent());
 			entry.setAuthor(content.getAuthor());

commafeed-server/src/main/resources/changelogs/db.changelog-5.2.xml

@@ -10,4 +10,10 @@
 			</column>
 		</addColumn>
 	</changeSet>
+
+	<changeSet id="content-direction" author="athou">
+		<addColumn tableName="FEEDENTRYCONTENTS">
+			<column name="direction" type="varchar(16)" />
+		</addColumn>
+	</changeSet>
 </databaseChangeLog>