sc-perf: do not add a million empty filter entries just to sort and discard

Which can happen if an (anonymous) database range as filter range was selected
to span an entire column of which most (the tail) is empty cells. The entries
are processed to be unique anyway. This significantly shortens the time to
display the filter dialog.

Happened with attachment
http://bugs.documentfoundation.org/attachment.cgi?id=136074 of bug
https://bugs.documentfoundation.org/show_bug.cgi?id=112258

Change-Id: Ia169911d6f23611a3b3ecbf291757465f1998210
Reviewed-on: https://gerrit.libreoffice.org/42118
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Eike Rathke <erack@redhat.com>

1 files changed, 17 insertions, 15 deletions

diff --git a/sc/source/core/data/column3.cxx b/sc/source/core/data/column3.cxx
index fcd529e14aff..af251cb8439c 100644
--- a/sc/source/core/data/column3.cxx
+++ b/sc/source/core/data/column3.cxx
@@ -47,6 +47,7 @@
 #include "editutil.hxx"
 #include "sharedformula.hxx"
 #include <listenercontext.hxx>
+#include "filterentries.hxx"
 
 #include <com/sun/star/i18n/LocaleDataItem.hpp>
 
@@ -2046,8 +2047,7 @@ namespace {
 class FilterEntriesHandler
 {
     ScColumn& mrColumn;
-    std::vector<ScTypedStrData>& mrStrings;
-    bool mbHasDates;
+    ScFilterEntries& mrFilterEntries;
 
     void processCell(SCROW nRow, ScRefCellValue& rCell)
     {
@@ -2058,7 +2058,7 @@ class FilterEntriesHandler
 
         if (rCell.hasString())
         {
-            mrStrings.push_back(ScTypedStrData(aStr));
+            mrFilterEntries.push_back(ScTypedStrData(aStr));
             return;
         }
 
@@ -2080,7 +2080,7 @@ class FilterEntriesHandler
                     OUString aErr = ScGlobal::GetErrorString(nErr);
                     if (!aErr.isEmpty())
                     {
-                        mrStrings.push_back(ScTypedStrData(aErr));
+                        mrFilterEntries.push_back(ScTypedStrData(aErr));
                         return;
                     }
                 }
@@ -2099,7 +2099,7 @@ class FilterEntriesHandler
             // special case for date values.  Disregard the time
             // element if the number format is of date type.
             fVal = rtl::math::approxFloor(fVal);
-            mbHasDates = true;
+            mrFilterEntries.mbHasDates = true;
             bDate = true;
             // Convert string representation to ISO 8601 date to eliminate
             // locale dependent behaviour later when filtering for dates.
@@ -2107,12 +2107,12 @@ class FilterEntriesHandler
             pFormatter->GetInputLineString( fVal, nIndex, aStr);
         }
         // maybe extend ScTypedStrData enum is also an option here
-        mrStrings.push_back(ScTypedStrData(aStr, fVal, ScTypedStrData::Value,bDate));
+        mrFilterEntries.push_back(ScTypedStrData(aStr, fVal, ScTypedStrData::Value,bDate));
     }
 
 public:
-    FilterEntriesHandler(ScColumn& rColumn, std::vector<ScTypedStrData>& rStrings) :
-        mrColumn(rColumn), mrStrings(rStrings), mbHasDates(false) {}
+    FilterEntriesHandler(ScColumn& rColumn, ScFilterEntries& rFilterEntries) :
+        mrColumn(rColumn), mrFilterEntries(rFilterEntries) {}
 
     void operator() (size_t nRow, double fVal)
     {
@@ -2140,27 +2140,29 @@ public:
 
     void operator() (const int nElemType, size_t nRow, size_t /* nDataSize */)
     {
-        if ( nElemType == sc::element_type_empty ) {
-            mrStrings.push_back(ScTypedStrData(OUString()));
+        if ( nElemType == sc::element_type_empty )
+        {
+            if (!mrFilterEntries.mbHasEmpties)
+            {
+                mrFilterEntries.push_back(ScTypedStrData(OUString()));
+                mrFilterEntries.mbHasEmpties = true;
+            }
             return;
         }
         ScRefCellValue aCell = mrColumn.GetCellValue(nRow);
         processCell(nRow, aCell);
     }
-
-    bool hasDates() const { return mbHasDates; }
 };
 
 }
 
 void ScColumn::GetFilterEntries(
     sc::ColumnBlockConstPosition& rBlockPos, SCROW nStartRow, SCROW nEndRow,
-    std::vector<ScTypedStrData>& rStrings, bool& rHasDates )
+    ScFilterEntries& rFilterEntries )
 {
-    FilterEntriesHandler aFunc(*this, rStrings);
+    FilterEntriesHandler aFunc(*this, rFilterEntries);
     rBlockPos.miCellPos =
         sc::ParseAll(rBlockPos.miCellPos, maCells, nStartRow, nEndRow, aFunc, aFunc);
-    rHasDates = aFunc.hasDates();
 }
 
 namespace {