[fpc-devel] Memory consumed by strings

[listmember]

Actually, load times are not --does not seem to be-- linear at all.

4 times larger file seems to take only twice as long.

I did one very simple test using 2 text files:

File 1: 384 MB (403,248,710 bytes)
File 2: 120 MB (126,680,448 bytes)

with the code below:

procedure TForm1.Button1Click(Sender: TObject);
var
   InitialValue1: Int64; //Initial PerformanceCounter
   Divisor1: Int64; //Performance CounterFrequency
   CurrentValue1: Int64; //Current PerformanceCounter
   Time1: double;
   Time2: double;
   Stream1: TMemoryStream;
   Index1: integer;
begin
   Memo1.Lines.Clear;
   QueryPerformanceFrequency(Divisor1);

   Index1 := 0;
   while Index1 < 100 do begin
     QueryPerformanceFrequency(CurrentValue1);
     QueryPerformanceCounter(InitialValue1);
     Stream1 := TMemoryStream.Create;
     Stream1.LoadFromFile(FILE_1);
     Stream1.Free;
     QueryPerformanceCounter(CurrentValue1);
     Time1 := (CurrentValue1 - InitialValue1) / Divisor1;

     QueryPerformanceCounter(InitialValue1);
     Stream1 := TMemoryStream.Create;
     Stream1.LoadFromFile(FILE_2);
     Stream1.Free;
     QueryPerformanceCounter(CurrentValue1);
     Time2 := (CurrentValue1 - InitialValue1) / Divisor1;

     Memo1.Lines.Add(Format('[400 MB: %3.3ns] [100 MB: %3.3ns]',
        [Time1, Time2]));
     Inc(Index1);
   end;
end;

Output:

[400 MB: 0.514s] [100 MB: 0.241s]
[400 MB: 0.535s] [100 MB: 0.239s]
[400 MB: 0.532s] [100 MB: 0.252s]
[400 MB: 0.532s] [100 MB: 0.245s]
[400 MB: 0.541s] [100 MB: 0.240s]
[400 MB: 0.533s] [100 MB: 0.240s]
[400 MB: 0.540s] [100 MB: 0.240s]
[400 MB: 0.532s] [100 MB: 0.245s]
[400 MB: 0.532s] [100 MB: 0.234s]
[400 MB: 0.538s] [100 MB: 0.240s]
[400 MB: 0.531s] [100 MB: 0.241s]
[400 MB: 0.533s] [100 MB: 0.242s]
[400 MB: 0.531s] [100 MB: 0.242s]
[400 MB: 0.585s] [100 MB: 0.252s]
[400 MB: 0.531s] [100 MB: 0.243s]
[400 MB: 0.531s] [100 MB: 0.289s]
[400 MB: 0.569s] [100 MB: 0.240s]
[400 MB: 0.532s] [100 MB: 0.235s]
[400 MB: 0.535s] [100 MB: 0.241s]
[400 MB: 0.533s] [100 MB: 0.242s]
[400 MB: 0.532s] [100 MB: 0.239s]
[400 MB: 0.531s] [100 MB: 0.241s]
[400 MB: 0.532s] [100 MB: 0.239s]
[400 MB: 0.532s] [100 MB: 0.245s]
[400 MB: 0.536s] [100 MB: 0.239s]
[400 MB: 0.534s] [100 MB: 0.256s]
[400 MB: 0.547s] [100 MB: 0.242s]
[400 MB: 0.535s] [100 MB: 0.261s]
[400 MB: 0.530s] [100 MB: 0.232s]
[400 MB: 0.541s] [100 MB: 0.239s]
[400 MB: 0.533s] [100 MB: 0.243s]
[400 MB: 0.535s] [100 MB: 0.244s]
[400 MB: 0.530s] [100 MB: 0.231s]
[400 MB: 0.540s] [100 MB: 0.240s]
[400 MB: 0.582s] [100 MB: 0.330s]
[400 MB: 0.557s] [100 MB: 0.231s]
[400 MB: 0.539s] [100 MB: 0.240s]
[400 MB: 0.531s] [100 MB: 0.230s]
[400 MB: 0.539s] [100 MB: 0.243s]
[400 MB: 0.531s] [100 MB: 0.246s]
[400 MB: 0.535s] [100 MB: 0.240s]
[400 MB: 0.532s] [100 MB: 0.279s]
[400 MB: 0.609s] [100 MB: 0.241s]
[400 MB: 0.533s] [100 MB: 0.249s]
[400 MB: 0.537s] [100 MB: 0.239s]
[400 MB: 0.531s] [100 MB: 0.242s]
[400 MB: 0.530s] [100 MB: 0.240s]
[400 MB: 0.535s] [100 MB: 0.238s]
[400 MB: 0.532s] [100 MB: 0.241s]
[400 MB: 0.536s] [100 MB: 0.242s]
[400 MB: 0.532s] [100 MB: 0.240s]
[400 MB: 0.534s] [100 MB: 0.230s]
[400 MB: 0.545s] [100 MB: 0.235s]
[400 MB: 0.538s] [100 MB: 0.240s]
[400 MB: 0.531s] [100 MB: 0.235s]
[400 MB: 0.536s] [100 MB: 0.229s]
[400 MB: 0.540s] [100 MB: 0.232s]
[400 MB: 0.540s] [100 MB: 0.243s]
[400 MB: 0.539s] [100 MB: 0.234s]
[400 MB: 0.540s] [100 MB: 0.230s]
[400 MB: 0.539s] [100 MB: 0.261s]
[400 MB: 0.535s] [100 MB: 0.242s]
[400 MB: 0.529s] [100 MB: 0.234s]
[400 MB: 0.538s] [100 MB: 0.234s]
[400 MB: 0.538s] [100 MB: 0.244s]
[400 MB: 0.535s] [100 MB: 0.242s]
[400 MB: 0.529s] [100 MB: 0.239s]
[400 MB: 0.532s] [100 MB: 0.251s]
[400 MB: 0.631s] [100 MB: 0.236s]
[400 MB: 0.535s] [100 MB: 0.242s]
[400 MB: 0.531s] [100 MB: 0.243s]
[400 MB: 0.531s] [100 MB: 0.239s]
[400 MB: 0.531s] [100 MB: 0.232s]
[400 MB: 0.543s] [100 MB: 0.239s]
[400 MB: 0.528s] [100 MB: 0.232s]
[400 MB: 0.538s] [100 MB: 0.242s]
[400 MB: 0.537s] [100 MB: 0.233s]
[400 MB: 0.537s] [100 MB: 0.241s]
[400 MB: 0.533s] [100 MB: 0.230s]
[400 MB: 0.543s] [100 MB: 0.242s]
[400 MB: 0.533s] [100 MB: 0.240s]
[400 MB: 0.531s] [100 MB: 0.253s]
[400 MB: 0.537s] [100 MB: 0.243s]
[400 MB: 0.547s] [100 MB: 0.238s]
[400 MB: 0.539s] [100 MB: 0.233s]
[400 MB: 0.545s] [100 MB: 0.257s]
[400 MB: 0.572s] [100 MB: 0.318s]
[400 MB: 0.563s] [100 MB: 0.238s]
[400 MB: 0.536s] [100 MB: 0.241s]
[400 MB: 0.533s] [100 MB: 0.249s]
[400 MB: 0.531s] [100 MB: 0.242s]
[400 MB: 0.534s] [100 MB: 0.241s]
[400 MB: 0.532s] [100 MB: 0.238s]
[400 MB: 0.537s] [100 MB: 0.241s]
[400 MB: 0.616s] [100 MB: 0.253s]
[400 MB: 0.536s] [100 MB: 0.228s]
[400 MB: 0.540s] [100 MB: 0.244s]
[400 MB: 0.539s] [100 MB: 0.237s]
[400 MB: 0.536s] [100 MB: 0.241s]
[400 MB: 0.539s] [100 MB: 0.236s]