Calculate print page ranges only when needed, cache in print state

When printing or exporting PDF, we need to calculate the page
print (cell) ranges for the current zoom level (document size).
This is quite a expensive thing to do as you need to inspect
the properties of individual cells.
The calculation ideally needs to be done only once per printing
request, but because of the rendering UNO API, this was done
everytime ScPrintFunc was instantiated, which is for every page
twice (once getRenderer is called and then when render is called).
To fix this performance issue, the print page ranges need to be
carried from one call to ScPrintFunc to the other. There already
is a print state (ScPrintState) which is used for exactly that,
but it didn't do this for print page ranges.
With this, PDF export time in a test case decreased from 17 sec to
around 3 sec.

Change-Id: I97ade0e397960c5c98379e4bb28e57c5411ff757
Reviewed-on: https://gerrit.libreoffice.org/45689Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

sc/source/ui/inc/printfun.hxx

@@ -66,6 +66,60 @@ struct ScPrintHFParam
     const SvxShadowItem* pShadow;
 };
 
+class ScPageRowEntry
+{
+private:
+    SCROW                    nStartRow;
+    SCROW                    nEndRow;
+    size_t                   nPagesX;
+    std::vector<bool>        aHidden;
+    //!     Cache Number of really visible?
+
+public:
+            ScPageRowEntry()    { nStartRow = nEndRow = 0; nPagesX = 0; }
+
+            ScPageRowEntry(const ScPageRowEntry& r);
+    ScPageRowEntry& operator=(const ScPageRowEntry& r);
+
+    SCROW   GetStartRow() const     { return nStartRow; }
+    SCROW   GetEndRow() const       { return nEndRow; }
+    size_t  GetPagesX() const       { return nPagesX; }
+    void    SetStartRow(SCROW n)    { nStartRow = n; }
+    void    SetEndRow(SCROW n)      { nEndRow = n; }
+
+    void    SetPagesX(size_t nNew);
+    void    SetHidden(size_t nX);
+    bool    IsHidden(size_t nX) const;
+
+    size_t  CountVisible() const;
+};
+
+namespace sc
+{
+
+class PrintPageRanges
+{
+public:
+    PrintPageRanges();
+
+    std::vector<SCCOL> m_aPageEndX;
+    std::vector<SCROW> m_aPageEndY;
+    std::vector<ScPageRowEntry> m_aPageRows;
+
+    size_t m_nPagesX;
+    size_t m_nPagesY;
+    size_t m_nTotalY;
+
+    bool m_bCalculated;
+
+    void calculate(ScDocument* pDoc, ScPageTableParam const & rTableParam,
+                   ScPageAreaParam const & rAreaParam,
+                   SCROW nStartRow, SCROW nEndRow, SCCOL nStartCol, SCCOL nEndCol,
+                   SCTAB nPrintTab);
+};
+
+}
+
 struct ScPrintState                         //  Save Variables from ScPrintFunc
 {
     SCTAB   nPrintTab;
@@ -80,6 +134,14 @@ struct ScPrintState                         //  Save Variables from ScPrintFunc
     long    nTotalPages;
     long    nPageStart;
     long    nDocPages;
+
+    // Additional state of page ranges
+    bool bSavedStateRanges;
+    size_t nTotalY;
+    std::vector<SCCOL> aPageEndX;
+    std::vector<SCROW> aPageEndY;
+    std::vector<ScPageRowEntry> aPageRows;
+
     ScPrintState()
         : nPrintTab(0)
         , nStartCol(0)
@@ -93,36 +155,9 @@ struct ScPrintState                         //  Save Variables from ScPrintFunc
         , nTotalPages(0)
         , nPageStart(0)
         , nDocPages(0)
-    {
-    }
-};
-
-class ScPageRowEntry
-{
-private:
-    SCROW                    nStartRow;
-    SCROW                    nEndRow;
-    size_t                   nPagesX;
-    std::vector<bool>        aHidden;
-    //!     Cache Number of really visible?
-
-public:
-            ScPageRowEntry()    { nStartRow = nEndRow = 0; nPagesX = 0; }
-
-            ScPageRowEntry(const ScPageRowEntry& r);
-    ScPageRowEntry& operator=(const ScPageRowEntry& r);
-
-    SCROW   GetStartRow() const     { return nStartRow; }
-    SCROW   GetEndRow() const       { return nEndRow; }
-    size_t  GetPagesX() const       { return nPagesX; }
-    void    SetStartRow(SCROW n)    { nStartRow = n; }
-    void    SetEndRow(SCROW n)      { nEndRow = n; }
-
-    void    SetPagesX(size_t nNew);
-    void    SetHidden(size_t nX);
-    bool    IsHidden(size_t nX) const;
-
-    size_t  CountVisible() const;
+        , bSavedStateRanges(false)
+        , nTotalY(0)
+    {}
 };
 
 class ScPrintFunc
@@ -200,13 +235,7 @@ private:
     SCCOL               nEndCol;
     SCROW               nEndRow;
 
-    std::vector< SCCOL >            maPageEndX;
-    std::vector< SCROW >            maPageEndY;
-    std::vector< ScPageRowEntry>    maPageRows;
-
-    size_t              nPagesX;
-    size_t              nPagesY;
-    size_t              nTotalY;
+    sc::PrintPageRanges m_aRanges;
 
     ScHeaderEditEngine* pEditEngine;
     SfxItemSet*         pEditDefaults;
@@ -274,7 +303,7 @@ public:
 
     void            ResetBreaks( SCTAB nTab );
 
-    void            GetPrintState( ScPrintState& rState );
+    void            GetPrintState(ScPrintState& rState, bool bSavePageRanges = false);
     bool            GetLastSourceRange( ScRange& rRange ) const;
     sal_uInt16      GetLeftMargin() const{return nLeftMargin;}
     sal_uInt16      GetRightMargin() const{return nRightMargin;}

sc/source/ui/unoobj/docuno.cxx

@@ -1296,6 +1296,7 @@ void ScModelObj::Notify( SfxBroadcaster& rBC, const SfxHint& rHint )
         }
 
         DELETEZ( pPrintFuncCache );     // must be deleted because it has a pointer to the DocShell
+        m_pPrintState.reset();
     }
     else if ( nId == SfxHintId::DataChanged )
     {
@@ -1303,6 +1304,7 @@ void ScModelObj::Notify( SfxBroadcaster& rBC, const SfxHint& rHint )
         //  (if a broadcast is added to SetDrawModified, is has to be tested here, too)
 
         DELETEZ( pPrintFuncCache );
+        m_pPrintState.reset();
 
         // handle "OnCalculate" sheet events (search also for VBA event handlers)
         if ( pDocShell )
@@ -1660,6 +1662,8 @@ sal_Int32 SAL_CALL ScModelObj::getRendererCount(const uno::Any& aSelection,
     }
     sal_Int32 nPages = pPrintFuncCache->GetPageCount();
 
+    m_pPrintState.reset();
+
     sal_Int32 nSelectCount = nPages;
     if ( !aPagesStr.isEmpty() )
     {
@@ -1806,7 +1810,7 @@ uno::Sequence<beans::PropertyValue> SAL_CALL ScModelObj::getRenderer( sal_Int32
         if (!m_pPrintState)
         {
             m_pPrintState.reset(new ScPrintState());
-            pPrintFunc->GetPrintState(*m_pPrintState);
+            pPrintFunc->GetPrintState(*m_pPrintState, true);
         }
 
         aPageSize.Width = TwipsToHMM( aTwips.Width());
@@ -1929,11 +1933,16 @@ void SAL_CALL ScModelObj::render( sal_Int32 nSelRenderer, const uno::Any& aSelec
     //  pages of the same sheet
 
 
-    ScPrintFunc aFunc( pDev, pDocShell, nTab, pPrintFuncCache->GetFirstAttr(nTab), nTotalPages, pSelRange, &aStatus.GetOptions() );
-    aFunc.SetDrawView( aDrawViewKeeper.mpDrawView );
-    aFunc.SetRenderFlag( true );
+    std::unique_ptr<ScPrintFunc, o3tl::default_delete<ScPrintFunc>> pPrintFunc;
+    if (m_pPrintState)
+        pPrintFunc.reset(new ScPrintFunc(pDev, pDocShell, *m_pPrintState, &aStatus.GetOptions()));
+    else
+        pPrintFunc.reset(new ScPrintFunc(pDev, pDocShell, nTab, pPrintFuncCache->GetFirstAttr(nTab), nTotalPages, pSelRange, &aStatus.GetOptions()));
+
+    pPrintFunc->SetDrawView( aDrawViewKeeper.mpDrawView );
+    pPrintFunc->SetRenderFlag( true );
     if( aStatus.GetMode() == SC_PRINTSEL_RANGE_EXCLUSIVELY_OLE_AND_DRAW_OBJECTS )
-        aFunc.SetExclusivelyDrawOleAndDrawObjects();
+        pPrintFunc->SetExclusivelyDrawOleAndDrawObjects();
 
     Range aPageRange( nRenderer+1, nRenderer+1 );
     MultiSelection aPage( aPageRange );
@@ -1969,7 +1978,13 @@ void SAL_CALL ScModelObj::render( sal_Int32 nSelRenderer, const uno::Any& aSelec
         }
     }
 
-    (void)aFunc.DoPrint( aPage, nTabStart, nDisplayStart, true, nullptr );
+    (void)pPrintFunc->DoPrint( aPage, nTabStart, nDisplayStart, true, nullptr );
+
+    if (!m_pPrintState)
+    {
+        m_pPrintState.reset(new ScPrintState());
+        pPrintFunc->GetPrintState(*m_pPrintState, true);
+    }
 
     //  resolve the hyperlinks for PDF export