Delphi接口性能问题

我对我的文本编辑器做了一些非常认真的重构。现在代码更少了,扩展组件也更容易了。我大量使用了OO设计,比如抽象类和接口。然而,我注意到在性能方面有一些损失。问题是读取大量的记录。当所有事情都发生在同一个对象中时,速度很快,但是当通过接口完成时,速度很慢。我已经做了一个最简单的程序来说明细节:

unit Unit3;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;

const
  N = 10000000;

type
  TRecord = record
    Val1, Val2, Val3, Val4: integer;
  end;

  TArrayOfRecord = array of TRecord;

  IMyInterface = interface
  ['{C0070757-2376-4A5B-AA4D-CA7EB058501A}']
    function GetArray: TArrayOfRecord;
    property Arr: TArrayOfRecord read GetArray;
  end;

  TMyObject = class(TComponent, IMyInterface)
  protected
    FArr: TArrayOfRecord;
  public
    procedure InitArr;
    function GetArray: TArrayOfRecord;
  end;

  TForm3 = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form3: TForm3;
  MyObject: TMyObject;

implementation

{$R *.dfm}

procedure TForm3.FormCreate(Sender: TObject);
var
  i: Integer;
  v1, v2, f: Int64;
  MyInterface: IMyInterface;
begin

  MyObject := TMyObject.Create(Self);

  try
    MyObject.InitArr;

    if not MyObject.GetInterface(IMyInterface, MyInterface) then
      raise Exception.Create('Note to self: Typo in the code');

    QueryPerformanceCounter(v1);

    // APPROACH 1: NO INTERFACE (FAST!)
  //  for i := 0 to high(MyObject.FArr) do
  //    if (MyObject.FArr[i].Val1 < MyObject.FArr[i].Val2) or
  //         (MyObject.FArr[i].Val3 < MyObject.FArr[i].Val4) then
  //      Tag := MyObject.FArr[i].Val1 + MyObject.FArr[i].Val2 - MyObject.FArr[i].Val3
  //               + MyObject.FArr[i].Val4;
    // END OF APPROACH 1


    // APPROACH 2: WITH INTERFACE (SLOW!)    
    for i := 0 to high(MyInterface.Arr) do
      if (MyInterface.Arr[i].Val1 < MyInterface.Arr[i].Val2) or
           (MyInterface.Arr[i].Val3 < MyInterface.Arr[i].Val4) then
        Tag := MyInterface.Arr[i].Val1 + MyInterface.Arr[i].Val2 - MyInterface.Arr[i].Val3
                 + MyInterface.Arr[i].Val4;
    // END OF APPROACH 2

    QueryPerformanceCounter(v2);
    QueryPerformanceFrequency(f);
    ShowMessage(FloatToStr((v2-v1) / f));

  finally

    MyInterface := nil;
    MyObject.Free;

  end;


end;

{ TMyObject }

function TMyObject.GetArray: TArrayOfRecord;
begin
  result := FArr;
end;

procedure TMyObject.InitArr;
var
  i: Integer;
begin
  SetLength(FArr, N);
  for i := 0 to N - 1 do
    with FArr[i] do
    begin
      Val1 := Random(high(integer));
      Val2 := Random(high(integer));
      Val3 := Random(high(integer));
      Val4 := Random(high(integer));
    end;
end;

end.

当我直接读取数据时,我得到的时间大约是0.14秒。但当我通过界面时,需要1.06秒。

有没有办法达到与以前一样的性能与这个新的设计?

我应该说我试着 PArrayOfRecord = ^TArrayOfRecord 重新定义 IMyInterface.arr: PArrayOfRecord 写下了 Arr^ 等在 for 循环。这帮了我很大的忙,然后我得到了0.22秒。但还是不够好。又是什么让开始这么慢?