tdf#109045: store en calendar separately in OnDemandCalendarWrapper

When working with pivot cache there's alternating use of
locale dependent and locale indepentent formats, which
causes unnecessary loading of calendars due to constant
switching.

OnDemandLocaleDataWrapper already does this, now do
something similar in OnDemandCalendarWrapper.

Change-Id: I3d64dbe8afa929cf416d87678762e82b45561d63
Reviewed-on: https://gerrit.libreoffice.org/39762Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Noel Grandin <noel.grandin@collabora.co.uk>

include/svl/ondemand.hxx

@@ -129,24 +129,30 @@ public:
     const   LocaleDataWrapper&  operator*() const   { return *get(); }
 };
 
-/** Load a calendar only if it's needed.
+/** Load a calendar only if it's needed. Keep calendar for "en" locale
+    separately, as there can be alternation between locale dependent and
+    locale independent formats.
     SvNumberformatter uses it upon switching locales.
+
     @ATTENTION If the default ctor is used the init() method MUST be called
     before accessing the calendar.
  */
 class OnDemandCalendarWrapper
 {
             css::uno::Reference< css::uno::XComponentContext > m_xContext;
+            css::lang::Locale  aEnglishLocale;
             css::lang::Locale  aLocale;
-    mutable std::unique_ptr<CalendarWrapper>
-                                pPtr;
-    mutable bool                bValid;
+    mutable css::lang::Locale  aLastAnyLocale;
+            std::unique_ptr<CalendarWrapper> pEnglishPtr;
+    mutable std::unique_ptr<CalendarWrapper> pAnyPtr;
 
 public:
                                 OnDemandCalendarWrapper()
-                                    : pPtr(nullptr)
-                                    , bValid(false)
-                                    {}
+                                    {
+                                        LanguageTag aEnglishLanguageTag(LANGUAGE_ENGLISH_US);
+                                        aEnglishLocale = aEnglishLanguageTag.getLocale();
+                                        aLastAnyLocale = aEnglishLocale;
+                                    }
 
             void                init(
                                     const css::uno::Reference< css::uno::XComponentContext >& rxContext,
@@ -155,25 +161,39 @@ public:
                                     {
                                         m_xContext = rxContext;
                                         changeLocale( rLocale );
-                                        pPtr.reset();
+                                        pEnglishPtr.reset(new CalendarWrapper( m_xContext ));
+                                        pEnglishPtr->loadDefaultCalendar( aEnglishLocale );
+                                        pAnyPtr.reset();
                                     }
 
             void                changeLocale( const css::lang::Locale& rLocale )
                                     {
-                                        bValid = false;
                                         aLocale = rLocale;
                                     }
 
             CalendarWrapper*    get() const
                                     {
-                                        if ( !bValid )
+                                        CalendarWrapper* pPtr;
+                                        if ( aLocale == aEnglishLocale )
                                         {
-                                            if ( !pPtr )
-                                                pPtr.reset(new CalendarWrapper( m_xContext ));
-                                            pPtr->loadDefaultCalendar( aLocale );
-                                            bValid = true;
+                                            pPtr = pEnglishPtr.get();
                                         }
-                                        return pPtr.get();
+                                        else
+                                        {
+                                            if ( !pAnyPtr )
+                                            {
+                                                pAnyPtr.reset(new CalendarWrapper( m_xContext ));
+                                                pAnyPtr->loadDefaultCalendar(aLocale);
+                                                aLastAnyLocale = aLocale;
+                                            }
+                                            else if ( aLocale != aLastAnyLocale )
+                                            {
+                                                pAnyPtr->loadDefaultCalendar( aLocale );
+                                                aLastAnyLocale = aLocale;
+                                            }
+                                            pPtr = pAnyPtr.get();
+                                        }
+                                        return pPtr;
                                     }
 
 };