1 files changed, 67 insertions, 0 deletions
diff --git a/src/libs/utils/scopedtimer.cpp b/src/libs/utils/scopedtimer.cpp
new file mode 100644
index 0000000000..6a4522e28d
--- /dev/null
+++ b/src/libs/utils/scopedtimer.cpp
@@ -0,0 +1,67 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include "scopedtimer.h"
+
+#include <QDebug>
+#include <QTime>
+
+#include <chrono>
+
+namespace Utils {
+
+static QString currentTime() { return QTime::currentTime().toString(Qt::ISODateWithMs); }
+
+using namespace std::chrono;
+
+static const char s_scoped[] = "SCOPED TIMER";
+static const char s_scopedCumulative[] = "STATIC SCOPED TIMER";
+
+class ScopedTimerPrivate
+{
+public:
+    QString header() const {
+        const char *scopedTimerType = m_data.m_cumulative ? s_scopedCumulative : s_scoped;
+        const QString prefix = QLatin1String(scopedTimerType) + " [" + currentTime() + "] ";
+        const QString infix = m_data.m_message.isEmpty()
+            ? QLatin1String(m_data.m_fileName) + ':' + QString::number(m_data.m_line)
+            : m_data.m_message;
+        return prefix + infix + ' ';
+    }
+
+    const ScopedTimerData m_data;
+    const time_point<system_clock, nanoseconds> m_start = system_clock::now();
+};
+
+ScopedTimer::ScopedTimer(const ScopedTimerData &data)
+    : d(new ScopedTimerPrivate{data})
+{
+    if (d->m_data.m_cumulative)
+        return;
+    qDebug().noquote().nospace() << d->header() << "started";
+}
+
+static int64_t toMs(int64_t ns) { return ns / 1000000; }
+
+ScopedTimer::~ScopedTimer()
+{
+    const auto elapsed = duration_cast<nanoseconds>(system_clock::now() - d->m_start);
+    QString suffix;
+    if (d->m_data.m_cumulative) {
+        const int64_t nsOld = d->m_data.m_cumulative->fetch_add(elapsed.count());
+        const int64_t msOld = toMs(nsOld);
+        const int64_t nsNew = nsOld + elapsed.count();
+        const int64_t msNew = toMs(nsNew);
+        // Always report the first hit, and later, as not to clog the debug output,
+        // only at 10ms resolution.
+        if (nsOld != 0 && msOld / 10 == msNew / 10)
+            return;
+
+        suffix = "cumulative timeout: " + QString::number(msNew) + "ms";
+    } else {
+        suffix = "stopped with timeout: " + QString::number(toMs(elapsed.count())) + "ms";
+    }
+    qDebug().noquote().nospace() << d->header() << suffix;
+}
+
+} // namespace Utils