Rewrite findMarker without tail recursion

... to avoid StackOverflowException
brailleapps · Apr 30, 2019 · 688c1d3 · 688c1d3
1 parent 9c0a2d9
commit 688c1d3
Showing 1 changed file with 47 additions and 50 deletions.
diff --git a/src/org/daisy/dotify/formatter/impl/search/SearchInfo.java b/src/org/daisy/dotify/formatter/impl/search/SearchInfo.java
@@ -155,60 +155,57 @@ boolean shouldAdjustOutOfBounds(PageDetails base, MarkerReferenceField markerRef
 		}
 	}
 
-	String findMarker(PageDetails page, MarkerReferenceField markerRef) {
-		if (page==null) {
-			return "";
-		}
-		if (markerRef.getSearchScope()==MarkerSearchScope.VOLUME || markerRef.getSearchScope()==MarkerSearchScope.DOCUMENT) {
-			throw new RuntimeException("Marker reference scope not implemented: " + markerRef.getSearchScope());
-		}
-		int dir = 1;
-		int index = 0;
-		int count = 0;
-		List<Marker> m;
-		boolean skipLeading = false;
-		if (markerRef.getSearchScope() == MarkerReferenceField.MarkerSearchScope.PAGE_CONTENT) {
-			skipLeading = true;
-		} else if (markerRef.getSearchScope() == MarkerReferenceField.MarkerSearchScope.SPREAD_CONTENT) {
-			PageDetails prevPageInVolume = getPageInVolumeWithOffset(page, -1, false);
-			if (prevPageInVolume == null || !page.isWithinSpreadScope(-1, prevPageInVolume)) {
+	String findMarker(final PageDetails page, final MarkerReferenceField markerRef) {
+		PageDetails currentPage = page;
+		while (currentPage!=null) {
+			if (markerRef.getSearchScope()==MarkerSearchScope.VOLUME || markerRef.getSearchScope()==MarkerSearchScope.DOCUMENT) {
+				throw new RuntimeException("Marker reference scope not implemented: " + markerRef.getSearchScope());
+			}
+			int dir = 1;
+			int index = 0;
+			int count = 0;
+			List<Marker> m;
+			boolean skipLeading = false;
+			if (markerRef.getSearchScope() == MarkerReferenceField.MarkerSearchScope.PAGE_CONTENT) {
 				skipLeading = true;
+			} else if (markerRef.getSearchScope() == MarkerReferenceField.MarkerSearchScope.SPREAD_CONTENT) {
+				PageDetails prevPageInVolume = getPageInVolumeWithOffset(currentPage, -1, false);
+				if (prevPageInVolume == null || !currentPage.isWithinSpreadScope(-1, prevPageInVolume)) {
+					skipLeading = true;
+				}
 			}
-		}
-		if (skipLeading) {
-			m = page.getContentMarkers();
-		} else {
-			m = page.getMarkers();
-		}
-		if (markerRef.getSearchDirection() == MarkerReferenceField.MarkerSearchDirection.BACKWARD) {
-			dir = -1;
-			index = m.size()-1;
-		}
-		while (count < m.size()) {
-			Marker m2 = m.get(index);
-			if (m2.getName().equals(markerRef.getName())) {
-				return m2.getValue();
+			if (skipLeading) {
+				m = currentPage.getContentMarkers();
+			} else {
+				m = currentPage.getMarkers();
+			}
+			if (markerRef.getSearchDirection() == MarkerReferenceField.MarkerSearchDirection.BACKWARD) {
+				dir = -1;
+				index = m.size()-1;
+			}
+			while (count < m.size()) {
+				Marker m2 = m.get(index);
+				if (m2.getName().equals(markerRef.getName())) {
+					return m2.getValue();
+				}
+				index += dir; 
+				count++;
+			}
+			if (markerRef.getSearchScope() == MarkerReferenceField.MarkerSearchScope.SEQUENCE ||
+				markerRef.getSearchScope() == MarkerSearchScope.SHEET && currentPage.isWithinSheetScope(dir) //||
+				//markerRef.getSearchScope() == MarkerSearchScope.SPREAD && page.isWithinSequenceSpreadScope(dir)
+				) {
+				//Keep while moving: next = page.getPageInScope(page.getSequenceParent(), dir, false);
+				currentPage = currentPage.getPageInScope(getContentsInSequence(currentPage.getSequenceId()), dir, false);
+			} //else if (markerRef.getSearchScope() == MarkerSearchScope.SPREAD && page.isWithinDocumentSpreadScope(dir)) {
+			  else if ((markerRef.getSearchScope() == MarkerSearchScope.SPREAD ||
+			           markerRef.getSearchScope() == MarkerSearchScope.SPREAD_CONTENT) && isWithinVolumeSpreadScope(currentPage, dir)) {
+				currentPage = getPageInVolumeWithOffset(currentPage, dir, false);
+			} else {
+				currentPage = null;
 			}
-			index += dir; 
-			count++;
-		}
-		PageDetails next = null;
-		if (markerRef.getSearchScope() == MarkerReferenceField.MarkerSearchScope.SEQUENCE ||
-			markerRef.getSearchScope() == MarkerSearchScope.SHEET && page.isWithinSheetScope(dir) //||
-			//markerRef.getSearchScope() == MarkerSearchScope.SPREAD && page.isWithinSequenceSpreadScope(dir)
-			) {
-			//Keep while moving: next = page.getPageInScope(page.getSequenceParent(), dir, false);
-			next = page.getPageInScope(getContentsInSequence(page.getSequenceId()), dir, false);
-		} //else if (markerRef.getSearchScope() == MarkerSearchScope.SPREAD && page.isWithinDocumentSpreadScope(dir)) {
-		  else if ((markerRef.getSearchScope() == MarkerSearchScope.SPREAD ||
-		           markerRef.getSearchScope() == MarkerSearchScope.SPREAD_CONTENT) && isWithinVolumeSpreadScope(page, dir)) {
-			next = getPageInVolumeWithOffset(page, dir, false);
-		}
-		if (next!=null) {
-			return findMarker(next, markerRef);
-		} else {
-			return "";
 		}
+		return "";
 	}
 
 	private Optional<PageDetails> getPageDetails(PageId p) {