From 9fa2a72a0bba4f7ab1b5efeb20073810fdeece12 Mon Sep 17 00:00:00 2001
From: Damocles <damocles@darkest.space>
Date: Wed, 15 Apr 2026 19:56:24 +0200
Subject: [PATCH] perf: gate cpuCores rebuild behind coreConsumers counter; 30s
 grace timer + history clear in SystemStats

---
 modules/Cpu.qml         | 12 ++++++++++++
 modules/SystemStats.qml | 38 ++++++++++++++++++++++++++------------
 2 files changed, 38 insertions(+), 12 deletions(-)

diff --git a/modules/Cpu.qml b/modules/Cpu.qml
index 00dfeed..a91a0a7 100644
--- a/modules/Cpu.qml
+++ b/modules/Cpu.qml
@@ -32,6 +32,18 @@ M.BarSection {
     readonly property bool _anyHover: root._hovered || hoverPanel.panelHovered
     readonly property bool _showPanel: _anyHover || _pinned
 
+    property bool _coreConsumerActive: false
+
+    on_ShowPanelChanged: {
+        if (_showPanel && !_coreConsumerActive) {
+            _coreConsumerActive = true;
+            M.SystemStats.coreConsumers++;
+        } else if (!_showPanel && _coreConsumerActive) {
+            _coreConsumerActive = false;
+            M.SystemStats.coreConsumers--;
+        }
+    }
+
     property M.ProcessList _procs: M.ProcessList {
         sortBy: "cpu"
         active: root._showPanel
diff --git a/modules/SystemStats.qml b/modules/SystemStats.qml
index 13c99a8..372a103 100644
--- a/modules/SystemStats.qml
+++ b/modules/SystemStats.qml
@@ -10,7 +10,19 @@ QtObject {
     // ── CPU ──────────────────────────────────────────────────────────────
     property int cpuUsage: 0
     property real cpuFreqGhz: 0
-    property var cpuCores: []        // [{usage, freq_ghz, history:[]}]
+    property var cpuCores: []        // [{usage, freq_ghz, history:[]}] — only rebuilt while coreConsumers > 0
+    property int coreConsumers: 0
+    onCoreConsumersChanged: {
+        if (coreConsumers > 0)
+            _coreGraceTimer.stop();
+        else
+            _coreGraceTimer.start();
+    }
+
+    property var _coreGraceTimer: Timer {
+        interval: 30000
+        onTriggered: root.cpuCores = []
+    }
     property var cpuCoreMaxFreq: []
     property var cpuCoreTypes: []
 
@@ -44,17 +56,19 @@ QtObject {
                     if (ev.type === "cpu") {
                         root.cpuUsage = ev.usage;
                         root.cpuFreqGhz = ev.freq_ghz;
-                        const histLen = 16;
-                        const prev = root.cpuCores;
-                        root.cpuCores = ev.cores.map((c, i) => {
-                            const oldHist = prev[i]?.history ?? [];
-                            const hist = oldHist.concat([c.usage]);
-                            return {
-                                usage: c.usage,
-                                freq_ghz: c.freq_ghz,
-                                history: hist.length > histLen ? hist.slice(hist.length - histLen) : hist
-                            };
-                        });
+                        if (root.coreConsumers > 0) {
+                            const histLen = 16;
+                            const prev = root.cpuCores;
+                            root.cpuCores = ev.cores.map((c, i) => {
+                                const oldHist = prev[i]?.history ?? [];
+                                const hist = oldHist.concat([c.usage]);
+                                return {
+                                    usage: c.usage,
+                                    freq_ghz: c.freq_ghz,
+                                    history: hist.length > histLen ? hist.slice(hist.length - histLen) : hist
+                                };
+                            });
+                        }
                     } else if (ev.type === "temp") {
                         root.tempCelsius = ev.celsius;
                     } else if (ev.type === "mem") {