sc-perf: lock drawing layer during creation of captions for Save

This gives an extra boost compared to commit
451c4cccc7e3ec3f1e046d3232cb52f6fc443f59 (see there for further details)
as it eliminates broadcasts to accessibility and thus obtaining text forwarders
and what not.

ScPostIt::CreateCaptionFromInitData() compared to that commit
from 145,055,889,118
to    63,386,691,509

Overall ScDocShell::SaveXML() from original state before that commit
Before: 370,433,720,090
After: 107,468,180,524

Reduced to 29% or speed-up by factor 3.45

Change-Id: Ife86476c9654739ed9adf25e775f7568ea9934c2

1 files changed, 14 insertions, 0 deletions

diff --git a/sc/source/filter/xml/xmlwrap.cxx b/sc/source/filter/xml/xmlwrap.cxx
index 7aa54c029138..f170f31f1b33 100644
--- a/sc/source/filter/xml/xmlwrap.cxx
+++ b/sc/source/filter/xml/xmlwrap.cxx
@@ -719,8 +719,22 @@ bool ScXMLImportWrapper::ExportToComponent(const uno::Reference<uno::XComponentC
 
 bool ScXMLImportWrapper::Export(bool bStylesOnly)
 {
+    // Prevent all broadcasting and repaints and notification of accessibility
+    // during mass creation of captions, which is a major bottleneck and not
+    // needed during Save.
+    ScDrawLayer* pDrawLayer = rDoc.GetDrawLayer();
+    bool bOldLock = bool();
+    if (pDrawLayer)
+    {
+        bOldLock = pDrawLayer->isLocked();
+        pDrawLayer->setLock(true);
+    }
+
     rDoc.CreateAllNoteCaptions();
 
+    if (pDrawLayer)
+        pDrawLayer->setLock(bOldLock);
+
     uno::Reference<uno::XComponentContext> xContext(comphelper::getProcessComponentContext());
 
     uno::Reference<xml::sax::XWriter> xWriter = xml::sax::Writer::create(xContext);