From 404f1bf51c78340910306c56d1fb077db89ddfa9 Mon Sep 17 00:00:00 2001
From: Paul Buetow <paul@buetow.org>
Date: Tue, 24 Feb 2026 21:36:00 +0200
Subject: flamegraph: batch writeFrame output in single write

---
 internal/flamegraph/svgwriter.go | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

(limited to 'internal/flamegraph')

diff --git a/internal/flamegraph/svgwriter.go b/internal/flamegraph/svgwriter.go
index 4457fba..b68f6d8 100644
--- a/internal/flamegraph/svgwriter.go
+++ b/internal/flamegraph/svgwriter.go
@@ -120,25 +120,22 @@ func renderFrames(bw *bufio.Writer, node *trieNode, rootTotal uint64, cfg SVGCon
 }
 
 func writeFrame(bw *bufio.Writer, name, title, fill string, x, y, w, h float64, depth, fontSize int) error {
-	_, err := fmt.Fprintf(bw, `<g class="frame" data-name="%s" data-x="%.3f" data-w="%.3f" data-depth="%d" data-base-fill="%s">`+"\n",
-		svgEscape(name), x, w, depth, fill)
-	if err != nil {
-		return err
-	}
-	if _, err = fmt.Fprintf(bw, `<title>%s</title><rect x="%.3f" y="%.3f" width="%.3f" height="%.3f" fill="%s"/>`+"\n",
-		svgEscape(title), x, y, w, h, fill); err != nil {
-		return err
-	}
+	textStyle := ""
 	labelStyle := ""
 	if w <= float64(fontSize*2) {
 		labelStyle = ` style="display:none"`
 	}
-	_, err = fmt.Fprintf(bw, `<text x="%.3f" y="%.3f"%s>%s</text>`+"\n",
-		x+3, y+float64(fontSize), labelStyle, svgEscape(name))
-	if err != nil {
-		return err
-	}
-	_, err = fmt.Fprintln(bw, "</g>")
+	if labelStyle != "" {
+		textStyle = labelStyle
+	}
+	_, err := fmt.Fprintf(bw, `<g class="frame" data-name="%s" data-x="%.3f" data-w="%.3f" data-depth="%d" data-base-fill="%s">
+<title>%s</title><rect x="%.3f" y="%.3f" width="%.3f" height="%.3f" fill="%s"/>
+<text x="%.3f" y="%.3f"%s>%s</text>
+</g>
+`,
+		svgEscape(name), x, w, depth, fill,
+		svgEscape(title), x, y, w, h, fill,
+		x+3, y+float64(fontSize), textStyle, svgEscape(name))
 	return err
 }
 
-- 
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