Componentes.Terceros.RemObjects/internal/5.0.30.691/1/Data Abstract for Delphi/Samples/Connection Pooling/ConnectionPoolingMain.pas

unit ConnectionPoolingMain;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, uDADriverManager, uDAClasses, StdCtrls, uDAInterfaces,
  uDAIBXDriver, uDAEngine, uDAADODriver, ExtCtrls, ComCtrls;

type
  TConnectionPoolingMainForm = class(TForm)
    DADriverManager: TDADriverManager;
    DAConnectionManager: TDAConnectionManager;
    Acquire1Button: TButton;
    cbConnections: TComboBox;
    DAADODriver: TDAADODriver;
    Release1Button: TButton;
    Memo: TMemo;
    Acquire2Button: TButton;
    Release2Button: TButton;
    Acquire3Button: TButton;
    Release3Button: TButton;
    Label1: TLabel;
    TrackBar: TTrackBar;
    lPoolTimeoutSeconds: TLabel;
    procedure FormCreate(Sender: TObject);
    procedure Acquire1ButtonClick(Sender: TObject);
    procedure Release1ButtonClick(Sender: TObject);
    procedure Acquire2ButtonClick(Sender: TObject);
    procedure Acquire3ButtonClick(Sender: TObject);
    procedure Release2ButtonClick(Sender: TObject);
    procedure Release3ButtonClick(Sender: TObject);
    procedure DAConnectionManagerConnectionAcquired(
      Sender: TDAConnectionManager; const Connection: IDAConnection);
    procedure DAConnectionManagerConnectionCreated(
      Sender: TDAConnectionManager; const Connection: IDAConnection);
    procedure DAConnectionManagerConnectionTimedOut(
      Sender: TDAConnectionManager);
    procedure TrackBarChange(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    fConnection,
      fConnection2,
      fConnection3: IDAConnection;
    procedure Log(Str: string);
  public

  end;

var
  ConnectionPoolingMainForm: TConnectionPoolingMainForm;

implementation

{$R *.dfm}

procedure TConnectionPoolingMainForm.FormCreate(Sender: TObject);
var
  i: integer;
begin
  for i := 0 to (DAConnectionManager.Connections.Count - 1) do
    cbConnections.Items.Add(DAConnectionManager.Connections[i].Name);

  cbConnections.ItemIndex := 0;
end;

procedure TConnectionPoolingMainForm.Acquire1ButtonClick(Sender: TObject);
begin
  if not assigned(fConnection) then begin
    fConnection := DAConnectionManager.NewConnection(cbConnections.Text);
    Log('Connection #1 acquired...');
  end;
end;

procedure TConnectionPoolingMainForm.Release1ButtonClick(Sender: TObject);
begin
  if assigned(fConnection) then begin
    fConnection := nil;
    Log('Connection #1 released');
  end;
end;

procedure TConnectionPoolingMainForm.Acquire2ButtonClick(Sender: TObject);
begin
  if not assigned(fConnection2) then begin
    fConnection2 := DAConnectionManager.NewConnection(cbConnections.Text);
    Log('Connection #2 acquired...');
  end;
end;

procedure TConnectionPoolingMainForm.Acquire3ButtonClick(Sender: TObject);
begin
  if not assigned(fConnection3) then begin
    fConnection3 := DAConnectionManager.NewConnection(cbConnections.Text);
    Log('Connection #3 acquired...');
  end;
end;

procedure TConnectionPoolingMainForm.Release2ButtonClick(Sender: TObject);
begin
  if assigned(fConnection2) then begin
    fConnection2 := nil;
    Log('Connection #2 released');
  end;
end;

procedure TConnectionPoolingMainForm.Release3ButtonClick(Sender: TObject);
begin
  if assigned(fConnection3) then begin
    fConnection3 := nil;
    Log('Connection #3 released');
  end;
end;

procedure TConnectionPoolingMainForm.DAConnectionManagerConnectionAcquired(
  Sender: TDAConnectionManager; const Connection: IDAConnection);
begin
  Log('EVENT ->  Connection acquired from the pool at ' + TimeToStr(Now));
end;

procedure TConnectionPoolingMainForm.DAConnectionManagerConnectionCreated(
  Sender: TDAConnectionManager; const Connection: IDAConnection);
begin
  Log('EVENT -> New connection created at ' + TimeToStr(Now));
end;

procedure TConnectionPoolingMainForm.DAConnectionManagerConnectionTimedOut(
  Sender: TDAConnectionManager);
begin
  Log('EVENT -> A connection timed out at ' + TimeToStr(Now));
end;

procedure TConnectionPoolingMainForm.TrackBarChange(Sender: TObject);
begin
  DAConnectionManager.PoolTimeoutSeconds := TrackBar.Position;
  lPoolTimeoutSeconds.Caption := Format('PoolTimeoutSeconds: %d', [TrackBar.Position]);
end;

procedure TConnectionPoolingMainForm.Log(Str: string);
begin
  Memo.Lines.Add(Str);
end;

procedure TConnectionPoolingMainForm.FormDestroy(Sender: TObject);
begin
 fConnection:=nil;
 fConnection2:=nil;
 fConnection3:=nil;
end;

end.