Support estimateUsageInBytes for SystemDependentData

Change-Id: I6074035ed8f90e452915e9ecffdbe9363375e126
Reviewed-on: https://gerrit.libreoffice.org/61306
Tested-by: Jenkins
Reviewed-by: Armin Le Grand <Armin.Le.Grand@cib.de>

1 files changed, 46 insertions, 1 deletions

diff --git a/basegfx/source/tools/systemdependentdata.cxx b/basegfx/source/tools/systemdependentdata.cxx
index 4153d35f7d55..c727462c7191 100644
--- a/basegfx/source/tools/systemdependentdata.cxx
+++ b/basegfx/source/tools/systemdependentdata.cxx
@@ -8,6 +8,7 @@
  */
 
 #include <basegfx/utils/systemdependentdata.hxx>
+#include <math.h>
 
 namespace basegfx
 {
@@ -62,7 +63,8 @@ namespace basegfx
 {
     SystemDependentData::SystemDependentData(
         SystemDependentDataManager& rSystemDependentDataManager)
-    :   mrSystemDependentDataManager(rSystemDependentDataManager)
+    :   mrSystemDependentDataManager(rSystemDependentDataManager),
+        mnCalculatedCycles(0)
     {
     }
 
@@ -70,6 +72,49 @@ namespace basegfx
     {
     }
 
+    sal_uInt32 SystemDependentData::calculateCombinedHoldCyclesInSeconds() const
+    {
+        if(0 == mnCalculatedCycles)
+        {
+            const sal_Int64 nBytes(estimateUsageInBytes());
+            const sal_uInt32 nSeconds(getHoldCyclesInSeconds());
+
+            // default is Seconds (minimal is one)
+            sal_uInt32 nResult(0 == nSeconds ? 1 : nSeconds);
+
+            if(0 != nBytes)
+            {
+                // use sqrt to get some curved shape. With a default of 60s we get
+                // a single second at 3600 byte. To get close to 10mb, multiply by
+                // a corresponding scaling factor
+                const double fScaleToMB(3600.0 / (1024.0 * 1024.0 * 10.0));
+
+                // also use a multiplier to move the start point higer
+                const double fMultiplierSeconds(10.0);
+
+                // calculate
+                nResult = static_cast<sal_uInt32>((fMultiplierSeconds * nSeconds) / sqrt(nBytes * fScaleToMB));
+
+                // minimal value is 1
+                if(nResult < 1)
+                {
+                    nResult = 1;
+                }
+
+                // maximal value is nSeconds
+                if(nResult > nSeconds)
+                {
+                    nResult = nSeconds;
+                }
+            }
+
+            // set locally (once, on-demand created, non-zero)
+            const_cast<SystemDependentData*>(this)->mnCalculatedCycles = nResult < 1 ? 1 : nResult;
+        }
+
+        return mnCalculatedCycles;
+    }
+
     sal_uInt32 SystemDependentData::getHoldCyclesInSeconds() const
     {
         // default implementation returns 60(s)