What is the fastest XML Parser available for Delphi?

Question

We have reasonably large XML strings which we currently parse using MSXML2

I have just tried using MSXML6 hoping for a speed improvement and have got nothing!

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Answer 1

Someday I have written very simple XML test suite. It serves MSXML (D7 MSXML3?), Omni XML (bit old) and Jedi XML (latest stable).

Test results for 1,52 MB file:

XML file loading time MSXML: 240,20 [ms]

XML node selections MSXML: 1,09 [s]

XML file loading time OmniXML: 2,25 [s]

XML node selections OmniXML: 1,22 [s]

XML file loading time JclSimpleXML: 2,11 [s]

and access violation for JclSimpleXML node selections :|

Unfortunately I actually haven't much time to correct above AV, but sorces are contained below...

fmuMain.pas

program XmlEngines;

uses
  FastMM4,
  Forms,
  fmuMain in 'fmuMain.pas' {fmMain},
  uXmlEngines in 'uXmlEngines.pas',
  ifcXmlEngine in 'ifcXmlEngine.pas';

{$R *.res}

begin
  Application.Initialize;
  Application.Title := 'XML Engine Tester';
  Application.CreateForm(TfmMain, fmMain);
  Application.Run;
end.

fmuMain.pas

unit fmuMain;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, xmldom, XMLIntf, msxmldom, XMLDoc,
  //
  ifcXmlEngine, StdCtrls;

type
  TfmMain = class(TForm)
    mmoDebug: TMemo;
    dlgOpen: TOpenDialog;

    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);

    procedure mmoDebugClick(Sender: TObject);

  private
    fXmlEngines: TInterfaceList;
    function Get_Engine(const aIx: Integer): IXmlEngine;

  protected
    property XmlEngine[const aIx: Integer]: IXmlEngine read Get_Engine;

    procedure Debug(const aInfo: string); // inline

  public
    procedure RegisterXmlEngine(const aEngine: IXmlEngine);

  end;

var
  fmMain: TfmMain;

implementation

{$R *.dfm}

uses
  uXmlEngines, TZTools;

{ TForm1 }

function TfmMain.Get_Engine(const aIx: Integer): IXmlEngine;
begin
  Result:= nil;
  Supports(fXmlEngines[aIx], IXmlEngine, Result)
end;

procedure TfmMain.RegisterXmlEngine(const aEngine: IXmlEngine);
var
  Ix: Integer;
begin
  if aEngine = nil then
    Exit; // WARRNING: program flow disorder

  for Ix:= 0 to Pred(fXmlEngines.Count) do
    if XmlEngine[Ix] = aEngine then
      Exit; // WARRNING: program flow disorder

  fXmlEngines.Add(aEngine)
end;

procedure TfmMain.FormCreate(Sender: TObject);
begin
  fXmlEngines:= TInterfaceList.Create();
  dlgOpen.InitialDir:= ExtractFileDir(ParamStr(0));
  RegisterXmlEngine(TMsxmlEngine.Create(Self));
  RegisterXmlEngine(TOmniXmlEngine.Create());
  RegisterXmlEngine(TJediXmlEngine.Create());
end;

procedure TfmMain.mmoDebugClick(Sender: TObject);

  procedure TestEngines(const aFilename: TFileName);

    procedure TestEngine(const aEngine: IXmlEngine);
    var
      PerfCheck: TPerfCheck;
      Ix: Integer;
    begin
      PerfCheck := TPerfCheck.Create();
      try

        PerfCheck.Init(True);
        PerfCheck.Start();
        aEngine.Load(aFilename);
        PerfCheck.Pause();
        Debug(Format(
          'XML file loading time %s: %s',
          [aEngine.Get_ID(), PerfCheck.TimeStr()]));

        if aEngine.Get_ValidNode() then
        begin
          PerfCheck.Start();
          for Ix:= 0 to 999999 do
            if aEngine.Get_ChildsCount() > 0 then
            begin

              aEngine.SelectChild(Ix mod aEngine.Get_ChildsCount());

            end
            else
              aEngine.SelectRootNode();

          PerfCheck.Pause();
          Debug(Format(
            'XML nodes selections %s: %s',
            [aEngine.Get_ID(), PerfCheck.TimeStr()]));
        end

      finally
        PerfCheck.Free();
      end
    end;

  var
    Ix: Integer;
  begin
    Debug(aFilename);
    for Ix:= 0 to Pred(fXmlEngines.Count) do
      TestEngine(XmlEngine[Ix])
  end;

var
  CursorBckp: TCursor;
begin
  if dlgOpen.Execute() then
  begin

    CursorBckp:= Cursor;
    Self.Cursor:= crHourGlass;
    mmoDebug.Cursor:= crHourGlass;
    try
      TestEngines(dlgOpen.FileName)
    finally
      Self.Cursor:= CursorBckp;
      mmoDebug.Cursor:= CursorBckp;
    end

  end
end;

procedure TfmMain.Debug(const aInfo: string);
begin
  mmoDebug.Lines.Add(aInfo)
end;

procedure TfmMain.FormDestroy(Sender: TObject);
begin
  fXmlEngines.Free()
end;

end.

ifcXmlEngine.pas

unit ifcXmlEngine;

interface

uses
  SysUtils;

type
  TFileName = SysUtils.TFileName;

  IXmlEngine = interface
    ['{AF77333B-9873-4FDE-A3B1-260C7A4D3357}']
    procedure Load(const aFilename: TFileName);
    procedure SelectRootNode();
    procedure SelectChild(const aIndex: Integer);
    procedure SelectParent();
    //
    function Get_ID(): string;
    function Get_ValidNode(): Boolean;
    function Get_ChildsCount(): Integer;
    function Get_HaveParent(): Boolean;
    //function Get_NodeName(): Boolean;
  end;

implementation

end.

uXmlEngines.pas

unit uXmlEngines;

interface

uses
  Classes,
  //
  XMLDoc, XMLIntf, OmniXml, JclSimpleXml,
  //
  ifcXmlEngine;

type
  TMsxmlEngine = class(TInterfacedObject, IXmlEngine)
  private
    fXmlDoc: XMLDoc.TXMLDocument;
    fNode: XMLIntf.IXMLNode;

  protected

  public
    constructor Create(const aOwner: TComponent);
    destructor Destroy; override;

    procedure Load(const aFilename: TFileName);
    procedure SelectRootNode();
    procedure SelectChild(const aIndex: Integer);
    procedure SelectParent();
    //
    function Get_ID(): string;
    function Get_ValidNode(): Boolean;
    function Get_ChildsCount(): Integer;
    function Get_HaveParent(): Boolean;
    //function Get_NodeName(): Boolean;

  end;

  TOmniXmlEngine = class(TInterfacedObject, IXmlEngine)
  private
    fXmlDoc: OmniXml.IXmlDocument;
    fNode: OmniXml.IXMLNode;

  protected

  public
    constructor Create;
    destructor Destroy; override;

    procedure Load(const aFilename: TFileName);
    procedure SelectRootNode();
    procedure SelectChild(const aIndex: Integer);
    procedure SelectParent();
    //
    function Get_ID(): string;
    function Get_ValidNode(): Boolean;
    function Get_ChildsCount(): Integer;
    function Get_HaveParent(): Boolean;
    //function Get_NodeName(): Boolean;

  end;

  TJediXmlEngine = class(TInterfacedObject, IXmlEngine)
  private
    fXmlDoc: TJclSimpleXML;
    fNode: TJclSimpleXMLElem;

  protected

  public
    constructor Create();
    destructor Destroy(); override;

    procedure Load(const aFilename: TFileName);
    procedure SelectRootNode();
    procedure SelectChild(const aIndex: Integer);
    procedure SelectParent();
    //
    function Get_ID(): string;
    function Get_ValidNode(): Boolean;
    function Get_ChildsCount(): Integer;
    function Get_HaveParent(): Boolean;
    //function Get_NodeName(): Boolean;

  end;

implementation

uses
  SysUtils;

{ TMsxmlEngine }

constructor TMsxmlEngine.Create(const aOwner: TComponent);
begin
  if aOwner = nil then
    raise Exception.Create('TMsxmlEngine.Create() -> invalid owner');

  inherited Create();
  fXmlDoc:= XmlDoc.TXmlDocument.Create(aOwner);
  fXmlDoc.ParseOptions:= [poPreserveWhiteSpace]
end;

destructor TMsxmlEngine.Destroy;
begin
  fXmlDoc.Free();
  inherited Destroy()
end;

function TMsxmlEngine.Get_ChildsCount: Integer;
begin
  Result:= fNode.ChildNodes.Count
end;

function TMsxmlEngine.Get_HaveParent: Boolean;
begin
  Result:= fNode.ParentNode <> nil
end;

function TMsxmlEngine.Get_ID: string;
begin
  Result:= 'MSXML'
end;

//function TMsxmlEngine.Get_NodeName: Boolean;
//begin
//  Result:= fNode.Text
//end;

function TMsxmlEngine.Get_ValidNode: Boolean;
begin
  Result:= fNode <> nil
end;

procedure TMsxmlEngine.Load(const aFilename: TFileName);
begin
  fXmlDoc.LoadFromFile(aFilename);
  SelectRootNode()
end;

procedure TMsxmlEngine.SelectChild(const aIndex: Integer);
begin
  fNode:= fNode.ChildNodes.Get(aIndex)
end;

procedure TMsxmlEngine.SelectParent;
begin
  fNode:= fNode.ParentNode
end;

procedure TMsxmlEngine.SelectRootNode;
begin
  fNode:= fXmlDoc.DocumentElement
end;

{ TOmniXmlEngine }

constructor TOmniXmlEngine.Create;
begin
  inherited Create();
  fXmlDoc:= OmniXml.TXMLDocument.Create();
  fXmlDoc.PreserveWhiteSpace:= true
end;

destructor TOmniXmlEngine.Destroy;
begin
  fXmlDoc:= nil;
  inherited Destroy()
end;

function TOmniXmlEngine.Get_ChildsCount: Integer;
begin
  Result:= fNode.ChildNodes.Length
end;

function TOmniXmlEngine.Get_HaveParent: Boolean;
begin
  Result:= fNode.ParentNode <> nil
end;

function TOmniXmlEngine.Get_ID: string;
begin
  Result:= 'OmniXML'
end;

//function TOmniXmlEngine.Get_NodeName: Boolean;
//begin
//  Result:= fNode.NodeName
//end;

function TOmniXmlEngine.Get_ValidNode: Boolean;
begin
  Result:= fNode <> nil
end;

procedure TOmniXmlEngine.Load(const aFilename: TFileName);
begin
  fXmlDoc.Load(aFilename);
  SelectRootNode()
end;

procedure TOmniXmlEngine.SelectChild(const aIndex: Integer);
begin
  fNode:= fNode.ChildNodes.Item[aIndex]
end;

procedure TOmniXmlEngine.SelectParent;
begin
  fNode:= fNode.ParentNode
end;

procedure TOmniXmlEngine.SelectRootNode;
begin
  fNode:= fXmlDoc.DocumentElement
end;

{ TJediXmlEngine }

constructor TJediXmlEngine.Create;
begin
  inherited Create();
  fXmlDoc:= TJclSimpleXML.Create();
end;

destructor TJediXmlEngine.Destroy;
begin
  fXmlDoc.Free();
  inherited Destroy()
end;

function TJediXmlEngine.Get_ChildsCount: Integer;
begin
  Result:= fNode.ChildsCount
end;

function TJediXmlEngine.Get_HaveParent: Boolean;
begin
  Result:= fNode.Parent <> nil
end;

function TJediXmlEngine.Get_ID: string;
begin
  Result:= 'JclSimpleXML';
end;

//function TJediXmlEngine.Get_NodeName: Boolean;
//begin
//  Result:= fNode.Name
//end;

function TJediXmlEngine.Get_ValidNode: Boolean;
begin
  Result:= fNode <> nil
end;

procedure TJediXmlEngine.Load(const aFilename: TFileName);
begin
  fXmlDoc.LoadFromFile(aFilename);
  SelectRootNode()
end;

procedure TJediXmlEngine.SelectChild(const aIndex: Integer);
begin
  fNode:= fNode.Items[aIndex]
end;

procedure TJediXmlEngine.SelectParent;
begin
  fNode:= fNode.Parent
end;

procedure TJediXmlEngine.SelectRootNode;
begin
  fNode:= fXmlDoc.Root
end;

end.