[PATCH v2 1/7] kernel-shark: Preserve markers when appending data

["Yordan Karadzhov (VMware)" <y.karadz@gmail.com>]

When an entry is selected in the KernelShark GUI (using marker A and
marker B) we only keep track the index of this entry inside the array
of entries loaded at the moment of selecting. However, then a data
file is appended, the new entries are merged to this array and the
array is sorted. As a result the index of the marker can/will point
to completely different entry.

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 src/KsDualMarker.hpp |  6 ++++++
 src/KsMainWindow.cpp | 24 ++++++++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/KsDualMarker.hpp b/src/KsDualMarker.hpp
index 0dcaf93..39c0ce2 100644
--- a/src/KsDualMarker.hpp
+++ b/src/KsDualMarker.hpp
@@ -154,6 +154,12 @@ public:
 
 	void updateLabels();
 
+	/** Get the index inside the data array marker A points to. */
+	ssize_t markerAPos() {return markerA()._isSet ? markerA()._pos : -1;}
+
+	/** Get the index inside the data array marker B points to. */
+	ssize_t markerBPos() {return markerB()._isSet ? markerB()._pos : -1;}
+
 signals:
 	/**
 	 * This signal is emitted when the Table View has to switch the color
diff --git a/src/KsMainWindow.cpp b/src/KsMainWindow.cpp
index d0a434a..fa893ce 100644
--- a/src/KsMainWindow.cpp
+++ b/src/KsMainWindow.cpp
@@ -571,8 +571,15 @@ void KsMainWindow::markEntry(ssize_t row, DualMarkerState st)
 /** Select given kshark_entry with a given maker. */
 void KsMainWindow::markEntry(const kshark_entry *e, DualMarkerState st)
 {
-	ssize_t row = kshark_find_entry_by_time(e->ts, _data.rows(),
-						0, _data.size() - 1);
+	ssize_t row;
+
+	if (!e) {
+		_mState.getMarker(st).reset();
+		return;
+	}
+
+	row = kshark_find_entry_by_time(e->ts, _data.rows(),
+					0, _data.size() - 1);
 
 	markEntry(row, st);
 }
@@ -1341,7 +1348,20 @@ void KsMainWindow::loadDataFile(const QString& fileName)
 /** Append trace data for file. */
 void KsMainWindow::appendDataFile(const QString& fileName)
 {
+	kshark_entry *eMarkA(nullptr), *eMarkB(nullptr);
+	int rowA = _mState.markerAPos();
+	int rowB = _mState.markerBPos();
+
+	if (rowA >= 0)
+		eMarkA = _data.rows()[rowA];
+
+	if (rowB >= 0)
+		eMarkB = _data.rows()[rowB];
+
 	_load(fileName, true);
+
+	markEntry(eMarkA, DualMarkerState::A);
+	markEntry(eMarkB, DualMarkerState::B);
 }
 
 void KsMainWindow::_error(const QString &mesg,
-- 
2.27.0