From 7f04a6654604ad656590d4b15d585ab950f2aa89 Mon Sep 17 00:00:00 2001
From: hjk <hjk@qt.io>
Date: Fri, 24 Feb 2023 12:17:03 +0100
Subject: [PATCH] Debugger: Introduce a cache for pre-rendered value columne
 entries

Change-Id: Ibdcac8a5ccaa3eab0723205b913056530c510280
Reviewed-by: David Schulz <david.schulz@qt.io>
---
 src/plugins/debugger/watchdata.h      |  3 +++
 src/plugins/debugger/watchhandler.cpp | 19 +++++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/plugins/debugger/watchdata.h b/src/plugins/debugger/watchdata.h
index c25e1962f9c..4ef57eacf18 100644
--- a/src/plugins/debugger/watchdata.h
+++ b/src/plugins/debugger/watchdata.h
@@ -78,6 +78,9 @@ public:
     bool            outdated = false;      // \internal item is to be removed.
     double          time = 0;              // Time used on the dumper side to produce this item
 
+    mutable QString  valueCache;           // Pre-computed displayed value
+    void updateValueCache() const;          // implemented in watchhandler.cpp
+
 private:
     void parseHelper(const GdbMi &input, bool maySort);
 };
diff --git a/src/plugins/debugger/watchhandler.cpp b/src/plugins/debugger/watchhandler.cpp
index f86bcb1c62e..4823a952b90 100644
--- a/src/plugins/debugger/watchhandler.cpp
+++ b/src/plugins/debugger/watchhandler.cpp
@@ -929,15 +929,22 @@ static QString displayName(const WatchItem *item)
     return result;
 }
 
-static QString displayValue(const WatchItem *item)
+
+void WatchItem::updateValueCache() const
 {
-    QString result = truncateValue(formattedValue(item));
-    result = watchModel(item)->removeNamespaces(result);
-    if (result.isEmpty() && item->address)
-        result += QString::fromLatin1("@0x" + QByteArray::number(item->address, 16));
+    valueCache = truncateValue(formattedValue(this));
+    valueCache = watchModel(this)->removeNamespaces(valueCache);
+    if (valueCache.isEmpty() && this->address)
+        valueCache += QString::fromLatin1("@0x" + QByteArray::number(this->address, 16));
 //    if (origaddr)
 //        result += QString::fromLatin1(" (0x" + QByteArray::number(origaddr, 16) + ')');
-    return result;
+}
+
+static QString displayValue(const WatchItem *item)
+{
+    if (item->valueCache.isEmpty())
+        item->updateValueCache();
+    return item->valueCache;
 }
 
 static QString displayType(const WatchItem *item)