imporove metrics capture logic

Author: deadlovelll

Lib/profiling/sampling/_heatmap_assets/heatmap_index_template.html

@@ -66,7 +66,7 @@
                 <div class="stat-card">
                     <div class="stat-icon">&#9201;</div>
                     <div class="stat-data">
-                        <span class="stat-value"><!-- DURATION --> sec</span>
+                        <span class="stat-value"><!-- DURATION --></span>
                         <span class="stat-label">Duration</span>
                     </div>
                     <div class="stat-sparkline"></div>

Lib/profiling/sampling/heatmap_collector.py

@@ -752,15 +752,17 @@ def _generate_index_html(self, index_path: Path, file_stats: List[FileStats]):
             missed_samples_class = "good"
 
         # Populate template
+        duration_sec = self.stats.get('duration_sec')
+        sample_rate = self.stats.get('sample_rate')
         replacements = {
             "<!-- INLINE_CSS -->": f"<style>\n{self._template_loader.index_css}\n</style>",
             "<!-- INLINE_JS -->": f"<script>\n{self._template_loader.index_js}\n</script>",
             "<!-- PYTHON_LOGO -->": self._template_loader.logo_html,
             "<!-- PYTHON_VERSION -->": f"{sys.version_info.major}.{sys.version_info.minor}",
             "<!-- NUM_FILES -->": f"{len(file_stats):n}",
             "<!-- TOTAL_SAMPLES -->": f"{self._total_samples:n}",
-            "<!-- DURATION -->": fmt(self.stats.get('duration_sec', 0)),
-            "<!-- SAMPLE_RATE -->": fmt(self.stats.get('sample_rate', 0)),
+            "<!-- DURATION -->": f"{fmt(duration_sec)} sec" if duration_sec is not None else "N/A",
+            "<!-- SAMPLE_RATE -->": fmt(sample_rate) if sample_rate is not None else "N/A",
             "<!-- ERROR_RATE -->": error_rate_str,
             "<!-- ERROR_RATE_WIDTH -->": str(error_rate_width),
             "<!-- ERROR_RATE_CLASS -->": error_rate_class,