datasnap 2011连接池，数据集对象池

那种往应用服务器中拖放一堆TDataSet, TDaTaSetProvider控件的做法，非常的笨拙。可以通过使用对象池来改进之。

 

数据集对象池

unit ServerMethodsUnit1;

interface

uses  SysUtils, Classes, DSServer, DB, Generics.Collections, DSService, Provider,  ADODB;

type  TServerMethods1 = class(TDSServerModule)    procedure DSServerModuleCreate(Sender: TObject);  private    { Private declarations }    ListofQuery : TDictionary<Integer,Tadoquery>;    ListofProvider : TDictionary<Integer,Tdatasetprovider>;    function _GetQuery(asql: string; exeNo: Integer) : Tadoquery;    function _GetPrv(sql: string; exeNo: Integer) : Tdatasetprovider;  public    { Public declarations }    function GetProviderName(sql: string; exeNo: Integer): string;  end;

implementation

{$R *.dfm}

uses StrUtils, DSServerContainer, uConst;

procedure TServerMethods1.DSServerModuleCreate(Sender: TObject);begin  Listofquery := TDictionary<Integer, Tadoquery>.Create;  Listofprovider := TDictionary<Integer, Tdatasetprovider>.Create;end;

function TServerMethods1._GetPrv(sql: string; exeNo: Integer): Tdatasetprovider;var  dbprv : Tdatasetprovider;begin  if ListofProvider.ContainsKey(exeNo) then     Result := ListofProvider[exeNo]  else  begin    if ListofProvider.Count <= g_MaxPoolSize then    begin      dbprv := TDataSetProvider.Create(Self);      dbprv.Name := 'dsp'+ IntToStr(exeNo);      dbprv.DataSet := _GetQuery(sql, exeNo);      ListofProvider.Add(exeNo, dbprv);      Result := dbprv;    end;  end;end;

function TServerMethods1._GetQuery(asql: string; exeNo: Integer): Tadoquery;var  qry : TADOQuery;begin  if Listofquery.ContainsKey(exeNo) then     Result := ListofQuery[exeNo]  else  begin    if ListofQuery.Count <= g_MaxPoolSize then    begin      qry := TADOQuery.Create(Self);      with qry do      begin        Connection := ServerContainer1.GetConnection;        Name := 'qry'+ IntToStr(exeNo);        close;        sql.Clear;        sql.Text := asql;        open;      end;      ListofQuery.Add(exeNo, qry);      Result := qry;    end;  end;end;

function TServerMethods1.GetProviderName(sql: string; exeNo: Integer): string;begin  Result := _GetPrv(sql, exeNo).Name;end;

end.

 

 

连接池

unit DSServerContainer;

interface

uses  SysUtils, Classes,   DSTCPServerTransport,  DSServer, DSCommonServer, DSAuth, DB, ADODB, Generics.Collections, DSService,  DBXDataSnap, DBXCommon, DSHTTPLayer, DBXinterbase, forms;

type  TServerContainer1 = class(TDataModule)    DSServer1: TDSServer;    DSTCPServerTransport1: TDSTCPServerTransport;    DSServerClass1: TDSServerClass;    procedure DSServerClass1GetClass(DSServerClass: TDSServerClass;      var PersistentClass: TPersistentClass);    procedure DataModuleCreate(Sender: TObject);    procedure DSServer1Disconnect(DSConnectEventObject: TDSConnectEventObject);  private    { Private declarations }    ListofConnection : TDictionary<Integer,TadoConnection>;  public    function GetConnection : TadoConnection;  end;

var  ServerContainer1: TServerContainer1;

implementation

uses Windows, ServerMethodsUnit1,uConst;

{$R *.dfm}

procedure TServerContainer1.DataModuleCreate(Sender: TObject);begin  ListofConnection := TDictionary<Integer, TadoConnection>.Create;end;

procedure TServerContainer1.DSServer1Disconnect(  DSConnectEventObject: TDSConnectEventObject);begin  if GetConnection <> nil then     GetConnection.Close;end;

procedure TServerContainer1.DSServerClass1GetClass(  DSServerClass: TDSServerClass; var PersistentClass: TPersistentClass);begin  PersistentClass := ServerMethodsUnit1.TServerMethods1;end;

function TServerContainer1.GetConnection: TadoConnection;var  dbconn : TadoConnection;begin  if ListofConnection.ContainsKey(TDSSessionManager.GetThreadSession.Id) then     Result := ListofConnection[TDSSessionManager.GetThreadSession.Id]  else  begin    if ListofConnection.Count <= g_MaxPoolSize then    begin      dbconn := TadoConnection.Create(Self);      dbconn.Name := 'con'+ IntToStr(TDSSessionManager.GetThreadSession.Id);      dbconn.LoginPrompt := false;      dbconn.ConnectionString := 'FILE NAME=' + extractfilepath(application.ExeName) + 'connect.udl';      ListofConnection.Add(TDSSessionManager.GetThreadSession.Id, dbconn);      Result := dbconn;    end;  end;end;

end.