Copy mail merge source instead of loading

Currently a mail merge loads the styles from the source document
and also loads the original source per mail merge dataset.

The new code is based on the MergeDocuments function and swaps the
loading with an internal document copy to improve mail merge
throughtput.

For a mail merge with 99 datasets and a two pages document,
callgrind shows an improvement from routhly 44 to 31 billion
inclusive instructions for the single SwXMailMerge::execute call.

Reviewed-on: https://gerrit.libreoffice.org/7433
Tested-by: Michael Stahl <mstahl@redhat.com>
Reviewed-by: Michael Stahl <mstahl@redhat.com>
(cherry picked from commit 8d11531565d746dd6a7938c4f3536ad34698092d)

Conflicts:

sw/source/ui/dbui/dbmgr.cxx

Change-Id: I6929ba371f81c3ea1f26ea3a25e7751bc53256e3

1 files changed, 14 insertions, 18 deletions

diff --git a/sw/source/ui/dbui/dbmgr.cxx b/sw/source/ui/dbui/dbmgr.cxx
index d94838c5b2d1..70a853248917 100644
--- a/sw/source/ui/dbui/dbmgr.cxx
+++ b/sw/source/ui/dbui/dbmgr.cxx
@@ -870,11 +870,8 @@ sal_Bool SwNewDBMgr::MergeMailFiles(SwWrtShell* pSourceShell,
         pSfxDispatcher->Execute( pSourceDocSh->HasName() ? SID_SAVEDOC : SID_SAVEASDOC, SFX_CALLMODE_SYNCHRON|SFX_CALLMODE_RECORD);
         if( !pSourceDocSh->IsModified() )
         {
-            SfxMedium* pOrig = pSourceDocSh->GetMedium();
-            String sSourceDocumentURL(pOrig->GetURLObject().GetMainURL( INetURLObject::NO_DECODE ));
-            const SfxFilter* pSfxFlt = SwIoSystem::GetFileFilter(
-                                                    sSourceDocumentURL, ::aEmptyStr );
-            const SfxFilter* pStoreToFilter = pSfxFlt;
+            const SfxFilter* pStoreToFilter = SwIoSystem::GetFileFilter(
+                pSourceDocSh->GetMedium()->GetURLObject().GetMainURL( INetURLObject::NO_DECODE ), ::aEmptyStr );
             SfxFilterContainer* pFilterContainer = SwDocShell::Factory().GetFilterContainer();
             const String* pStoreToFilterOptions = 0;
 
@@ -923,14 +920,7 @@ sal_Bool SwNewDBMgr::MergeMailFiles(SwWrtShell* pSourceShell,
                 pTargetView->AttrChangedNotify( &pTargetView->GetWrtShell() );
                 pTargetShell = pTargetView->GetWrtShellPtr();
                 //copy the styles from the source to the target document
-                SwgReaderOption aOpt;
-                aOpt.SetTxtFmts( sal_True );
-                aOpt.SetFrmFmts( sal_True );
-                aOpt.SetPageDescs( sal_True );
-                aOpt.SetNumRules( sal_True );
-                aOpt.SetMerge( sal_False );
-                pTargetView->GetDocShell()->LoadStylesFromFile(
-                        sSourceDocumentURL, aOpt, sal_True );
+                pTargetView->GetDocShell()->_LoadStyles( *pSourceDocSh, sal_True );
                 //determine the page style and number used at the start of the source document
                 pSourceShell->SttEndDoc(sal_True);
                 nStartingPageNo = pSourceShell->GetVirtPageNum();
@@ -1027,13 +1017,19 @@ sal_Bool SwNewDBMgr::MergeMailFiles(SwWrtShell* pSourceShell,
                         for (sal_uInt16 i = 0; i < 10; i++)
                             Application::Reschedule();
 
-                        // Create and save new document
                         // The SfxObjectShell will be closed explicitly later but it is more safe to use SfxObjectShellLock here
-                        SfxObjectShellLock xWorkDocSh( new SwDocShell( SFX_CREATE_MODE_INTERNAL ));
-                        SfxMedium* pWorkMed = new SfxMedium( sSourceDocumentURL, STREAM_STD_READ );
-                        pWorkMed->SetFilter( pSfxFlt );
+                        SfxObjectShellLock xWorkDocSh;
+                        // copy the source document
+                        if( 1 == nDocNo && (bAsSingleFile || rMergeDescriptor.bCreateSingleFile) )
+                        {
+                            uno::Reference< util::XCloneable > xClone( pSourceDocSh->GetModel(), uno::UNO_QUERY);
+                            uno::Reference< lang::XUnoTunnel > xWorkDocShell( xClone->createClone(), uno::UNO_QUERY);
+                            SwXTextDocument* pWorkModel = reinterpret_cast<SwXTextDocument*>(xWorkDocShell->getSomething(SwXTextDocument::getUnoTunnelId()));
+                            xWorkDocSh = pWorkModel->GetDocShell();
+                        }
+                        else
+                            xWorkDocSh = pSourceDocSh->GetDoc()->CreateCopy( true );
 
-                        if (xWorkDocSh->DoLoad(pWorkMed))
                         {
                             //create a view frame for the document
                             SfxViewFrame* pWorkFrame = SfxViewFrame::LoadHiddenDocument( *xWorkDocSh, 0 );