From ed326d947277b25f1e708ce47636dd7e25a6ff6d Mon Sep 17 00:00:00 2001
From: Brice Dutheil <brice.dutheil@gmail.com>
Date: Wed, 16 Mar 2022 13:30:25 +0100
Subject: [PATCH] perf(flamegraph): Only repaint hovered rectangle

---
 .../fireplace/flamegraph/FlameGraph.java      | 11 +++---
 .../flamegraph/FlameGraphPainter.java         | 37 ++++++++++++++-----
 2 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/fireplace-swing/src/main/java/io/github/bric3/fireplace/flamegraph/FlameGraph.java b/fireplace-swing/src/main/java/io/github/bric3/fireplace/flamegraph/FlameGraph.java
index 455be491..eaba1cd5 100644
--- a/fireplace-swing/src/main/java/io/github/bric3/fireplace/flamegraph/FlameGraph.java
+++ b/fireplace-swing/src/main/java/io/github/bric3/fireplace/flamegraph/FlameGraph.java
@@ -187,6 +187,7 @@ public void setData(List<FrameBox<T>> frames,
         canvas.setFlameGraphPainter(flameGraphPainter);
         canvas.setToolTipTextFunction(tooltipTextFunction);
         canvas.invalidate();
+        canvas.repaint();
     }
 
     /**
@@ -287,9 +288,9 @@ public void mouseClicked(MouseEvent e) {
                       .ifPresent(fgp -> {
                           fgp.toggleSelectedFrameAt(
                                   (Graphics2D) viewPort.getView().getGraphics(),
-                                  point
+                                  point,
+                                  (frame, r) -> canvas.repaint()
                           );
-                          scrollPane.repaint();
                       });
             }
         }
@@ -308,7 +309,7 @@ public void mouseExited(MouseEvent e) {
                 var scrollPane = (JScrollPane) e.getComponent();
                 canvas.getFlameGraphPainter()
                       .ifPresent(FlameGraphPainter::stopHover);
-                scrollPane.repaint();
+                canvas.repaint();
             }
         }
 
@@ -328,9 +329,9 @@ public void mouseMoved(MouseEvent e) {
                   .ifPresent(fgp -> fgp.hoverFrameAt(
                           (Graphics2D) view.getGraphics(),
                           point,
-                          frame -> {
+                          (frame, r) -> {
                               canvas.setToolTipText(frame);
-                              scrollPane.repaint();
+                              canvas.repaint(r);
                           }
                   ));
         }
diff --git a/fireplace-swing/src/main/java/io/github/bric3/fireplace/flamegraph/FlameGraphPainter.java b/fireplace-swing/src/main/java/io/github/bric3/fireplace/flamegraph/FlameGraphPainter.java
index 99c77684..634601a3 100644
--- a/fireplace-swing/src/main/java/io/github/bric3/fireplace/flamegraph/FlameGraphPainter.java
+++ b/fireplace-swing/src/main/java/io/github/bric3/fireplace/flamegraph/FlameGraphPainter.java
@@ -14,6 +14,7 @@
 import java.awt.*;
 import java.util.List;
 import java.util.Optional;
+import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
@@ -222,14 +223,14 @@ private void paint(Graphics2D g2, Rectangle visibleRect, boolean minimapMode) {
             var nowWidth = g2d.getFontMetrics().stringWidth(drawTimeMs);
             g2d.setColor(Color.DARK_GRAY);
             g2d.fillRect(visibleRect.x + visibleRect.width - nowWidth - textBorder * 2,
-                        visibleRect.y + visibleRect.height - frameBoxHeight,
-                        nowWidth + textBorder * 2,
-                        frameBoxHeight);
+                         visibleRect.y + visibleRect.height - frameBoxHeight,
+                         nowWidth + textBorder * 2,
+                         frameBoxHeight);
 
             g2d.setColor(Color.YELLOW);
             g2d.drawString(drawTimeMs,
-                          visibleRect.x + visibleRect.width - nowWidth - textBorder,
-                          visibleRect.y + visibleRect.height - textBorder);
+                           visibleRect.x + visibleRect.width - nowWidth - textBorder,
+                           visibleRect.y + visibleRect.height - textBorder);
         }
 
         g2d.dispose();
@@ -328,6 +329,17 @@ private Rectangle paintFrameRectangle(Graphics2D g2, Rectangle frameRect, Color
         return frameRect;
     }
 
+    public Rectangle getFrameRectangle(Graphics2D g2, FrameBox<T> frame) {
+        var frameBoxHeight = getFrameBoxHeight(g2);
+
+        var rect = new Rectangle();
+        rect.x = (int) (flameGraphWidth * frame.startX); // + internalPadding;
+        rect.width = (int) (flameGraphWidth * frame.endX) - rect.x; // - internalPadding;
+        rect.y = frameBoxHeight * frame.stackDepth;
+        rect.height = frameBoxHeight;
+        return rect;
+    }
+
     public Optional<FrameBox<T>> getFrameAt(Graphics2D g2, Point point) {
         int depth = point.y / getFrameBoxHeight(g2);
         double xLocation = ((double) point.x) / flameGraphWidth;
@@ -337,21 +349,28 @@ public Optional<FrameBox<T>> getFrameAt(Graphics2D g2, Point point) {
                      .findFirst();
     }
 
-    public void toggleSelectedFrameAt(Graphics2D g2, Point point) {
+    public void toggleSelectedFrameAt(Graphics2D g2, Point point, BiConsumer<FrameBox<T>, Rectangle> toggleConsumer) {
         getFrameAt(
                 g2,
                 point
-        ).ifPresent(frame -> selectedFrame = selectedFrame == frame ? null : frame);
+        ).ifPresent(frame -> {
+            selectedFrame = selectedFrame == frame ? null : frame;
+            toggleConsumer.accept(frame, getFrameRectangle(g2, frame));
+        });
     }
 
-    public void hoverFrameAt(Graphics2D g2, Point point, Consumer<FrameBox<T>> hoverConsumer) {
+    public void hoverFrameAt(Graphics2D g2, Point point, BiConsumer<FrameBox<T>, Rectangle> hoverConsumer) {
         getFrameAt(
                 g2,
                 point
         ).ifPresentOrElse(frame -> {
+                              var oldHoveredFrame = hoveredFrame;
                               hoveredFrame = frame;
                               if (hoverConsumer != null) {
-                                  hoverConsumer.accept(frame);
+                                  hoverConsumer.accept(frame, getFrameRectangle(g2, frame));
+                                  if (oldHoveredFrame != null) {
+                                      hoverConsumer.accept(oldHoveredFrame, getFrameRectangle(g2, oldHoveredFrame));
+                                  }
                               }
                           },
                           this::stopHover);