tdf#136238 speed up deleting large cross page table

Goes from more than 30s to less than 1s on my pc.

We were getting stuck inside the loop in sw::UndoManager::AddUndoAction,
because the RemoveOldestUndoAction was continually doing nothing because
it was hitting the
if ( IsInListAction()
{
assert(!"SfxUndoManager::RemoveOldestUndoActions: cannot remove a
not-yet-closed list action!");
return;
}

code.

Which means that there is some bug here, but I'm not sure what. We are
deep inside the delete logic at that point, and it doesn't seem
unreasonable to opportunistically delete some of the UNDO list at that
point.

So the real fix is just the conversion from a while loop to an if-check.

Change-Id: Ie2707009dd6574b996421f67d952ab9fdaaaf6aa
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/102378
Tested-by: Noel Grandin <noel.grandin@collabora.co.uk>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

3 files changed, 11 insertions, 9 deletions

diff --git a/include/svl/undo.hxx b/include/svl/undo.hxx
index 2757967aaee4..0847d89811c0 100644
--- a/include/svl/undo.hxx
+++ b/include/svl/undo.hxx
@@ -291,7 +291,7 @@ public:
 
     /** removes the oldest Undo actions from the stack
     */
-    void            RemoveOldestUndoAction();
+    void            RemoveOldestUndoActions(sal_Int32 nNumToDelete);
 
     void dumpAsXml(xmlTextWriterPtr pWriter) const;
 
diff --git a/svl/source/undo/undo.cxx b/svl/source/undo/undo.cxx
index b678fba83948..46c785557416 100644
--- a/svl/source/undo/undo.cxx
+++ b/svl/source/undo/undo.cxx
@@ -1123,18 +1123,22 @@ bool SfxUndoManager::HasTopUndoActionMark( UndoStackMark const i_mark )
 }
 
 
-void SfxUndoManager::RemoveOldestUndoAction()
+void SfxUndoManager::RemoveOldestUndoActions(sal_Int32 nNumToDelete)
 {
     UndoManagerGuard aGuard( *m_xData );
 
-    if ( IsInListAction() && ( m_xData->pUndoArray->nCurUndoAction == 1 ) )
+    if ( ImplIsInListAction_Lock() && ( m_xData->pUndoArray->nCurUndoAction == 1 ) )
     {
         assert(!"SfxUndoManager::RemoveOldestUndoActions: cannot remove a not-yet-closed list action!");
         return;
     }
 
-    aGuard.markForDeletion( m_xData->pUndoArray->Remove( 0 ) );
-    --m_xData->pUndoArray->nCurUndoAction;
+    while (nNumToDelete>0 && !m_xData->pUndoArray->maUndoActions.empty())
+    {
+        aGuard.markForDeletion( m_xData->pUndoArray->Remove( 0 ) );
+        --m_xData->pUndoArray->nCurUndoAction;
+        --nNumToDelete;
+    }
     ImplCheckEmptyActions();
 }
 
diff --git a/sw/source/core/undo/docundo.cxx b/sw/source/core/undo/docundo.cxx
index ce416250f2b6..73a6b8bbe6da 100644
--- a/sw/source/core/undo/docundo.cxx
+++ b/sw/source/core/undo/docundo.cxx
@@ -537,10 +537,8 @@ void UndoManager::AddUndoAction(std::unique_ptr<SfxUndoAction> pAction, bool bTr
     }
 
     // if the undo nodes array is too large, delete some actions
-    while (UNDO_ACTION_LIMIT < GetUndoNodes().Count())
-    {
-        RemoveOldestUndoAction();
-    }
+    if (UNDO_ACTION_LIMIT < GetUndoNodes().Count())
+        RemoveOldestUndoActions(GetUndoNodes().Count() - UNDO_ACTION_LIMIT);
 }
 
 namespace {