Ermitteln der Größe des Arbeitsspeichers

Ermitteln der Größe des ArbeitsspeichersOktober 2013

Nützlich für Java-Programme, da dann ein passender Wert für -Xmx vom Setup eingestellt werden kann (im Beispiel unten 3/4 des Gesamtspeichers).

// Get memory size. Note: Might need at least InnoSetup 5.5.3 UNICODE VERSION!
// See http://stackoverflow.com/questions/17026867/inno-setup-how-can-i-check-system-specs-before-during-installation
type
  // the following mapping of the DWORDLONG data type is wrong; 
  // the correct type is a 64-bit unsigned integer which is not
  // available in InnoSetup Pascal Script at this time, so max.
  // values of the following fields will be limited to quite a
  // big reserve of 8589,934.592 GB of RAM; I hope enough for
  // the next versions of Windows :-)
  DWORDLONG = Int64;
  TMemoryStatusEx = record
    dwLength: DWORD;
    dwMemoryLoad: DWORD;
    ullTotalPhys: DWORDLONG;
    ullAvailPhys: DWORDLONG;
    ullTotalPageFile: DWORDLONG;
    ullAvailPageFile: DWORDLONG;
    ullTotalVirtual: DWORDLONG;
    ullAvailVirtual: DWORDLONG;
    ullAvailExtendedVirtual: DWORDLONG;
  end;

function GlobalMemoryStatusEx(var lpBuffer: TMemoryStatusEx): BOOL;
  external 'GlobalMemoryStatusEx@kernel32.dll stdcall';

// get 3/4 of memory size in MB as string containing only numbers
function getThreeForthOfMemoryInMb(): String;
var
  MemoryStatus: TMemoryStatusEx;
begin
  MemoryStatus.dwLength := SizeOf(MemoryStatus);
  GlobalMemoryStatusEx(MemoryStatus)
  result := Int64ToStr(MemoryStatus.ullTotalPhys * 3 / 4 / 1024 / 1024)
end;