Topic: Speedy code

[cadpro]

Hi,

How do I make this code faster?

Code: [Select]

dbxDoc = CType(AcadApp.GetInterfaceObject("ObjectDBX.AxDbDocument.17"), AxDbDocument)

        dbxDoc.Open(dwgFile)

         Dim ms As AcadEntity
 
        For Each ms In dbxDoc.ModelSpace
            If TypeOf ms Is AcadExternalReference Then
                Dim intIndex As Integer = Array.IndexOf(Src, ms.Name.ToString.ToLower)
                If intIndex >= 0 Then
                    tbl.Rows.Add(ms.Name, dwgFile, ms.Path)
                ElseIf String.IsNullOrEmpty(txtXrefs.Text) Then
                    tbl.Rows.Add(ms.Name, dwgFile, ms.Path, "")
                End If
            End If
         Next

        For Each ms In dbxDoc.PaperSpace
            If TypeOf ms Is AcadExternalReference Then
                 Dim intIndex As Integer = Array.IndexOf(Src, ms.Name.ToString.ToLower)
                If intIndex >= 0 Then
                    tbl.Rows.Add(ms.Name, dwgFile, ms.Path)
                ElseIf String.IsNullOrEmpty(txtXrefs.Text) Then
                    tbl.Rows.Add(ms.Name, dwgFile, ms.Path, "")
                End If
            End If
        Next
This is to get all parent xrefs only from a drawing.

Thanks

[pkohut]

How slow is it?  I guess where do you think the bottle neck might be?
I don't know is the slowness from the drawing open?

Paul

[ReneRam]

just a hint from:

http://www.dotnet2themax.com/ShowContent.aspx?ID=b7ab9163-1a7c-43c5-bb9a-0540f3e6be1c

that I got a few years ago. I thought I had also the ebook, but in any case...

"Iterating a collection with <For each... Next> is slower than <For counter = ... To ... Next>", I think I remember that it was because the For Each creates a copy of the object in the collection at each step or something like that; I'm sure the gurus here can explain the reason, but in any case I have made some tests and with large collections of complex objects I found out it's verified. So in your case I would create a SelectionSet of the ExternalReferences and then run the iteration with a "For ... to collection counted items... Next".

[Draftek]

Offhand I'd say create a selection set with a filter to eliminate iterating every entity in the database.

[cadpro]

Previously my code was as follows:

Code: [Select]

        Dim blk As AcadBlock
        Dim blks As AcadBlocks
        blks = dbxDoc.Blocks

        Dim Src() As String
        Src = txtXrefs.Text.ToLower.Split(",".ToCharArray)
        Array.Sort(Src)

        For Each blk In blks
           If blk.IsXRef Then
           Dim intIndex As Integer = Array.IndexOf(Src, blk.Name.ToString.ToLower)
                    If intIndex >= 0 Then
                        tbl.Rows.Add(blk.Name, dwgFile, blk.Path)
                    ElseIf String.IsNullOrEmpty(txtXrefs.Text) Then
                       tbl.Rows.Add(blk.Name, dwgFile, blk.Path, "")
                    End If
                End If
                'End If
            End If
        Next
This was extremely fast, but the problem was that it displays even nested xrefs, which I don't want to.

Offhand I'd say create a selection set with a filter to eliminate iterating every entity in the database.

Draftek:
How do I go about it?

Thanks

[T.Willey]

Use ' GetHostDwgXrefGraph '.  You can tell which xrefs are nested, and which are not.  If you want to select them, then you can get that information from the block table record of the xrefs.  No need to step through the whole drawing to get this information.  If you just want to get the xref information to store it, then you don't have to go any further than what each node has, as the information is all there.

A few examples ( one might seem familiar ).
[ http://www.theswamp.org/index.php?topic=22884.0 ]
[ http://www.theswamp.org/index.php?topic=12272.msg152426#msg152426 ]

[ReneRam]

Take a look also to this:

http://www.theswamp.org/index.php?topic=24524.msg295771#msg295771

and a little testing sub:

Code: [Select]

    Sub XrefTester()
        Dim myDWG As ApplicationServices.Document = ApplicationServices.Application.DocumentManager.MdiActiveDocument
        Dim myDB As DatabaseServices.Database = myDWG.Database
        Dim xrefGraph As XrefGraph = myDB.GetHostDwgXrefGraph(True)

        Using tr As Transaction = myDB.TransactionManager.StartTransaction()
            For i As Integer = 0 To xrefGraph.NumNodes - 1
                Dim xrefName As String = Nothing
                Dim xrefGraphNode As XrefGraphNode = xrefGraph.GetXrefNode(i)
                ' Do whatever you need
                Debug.Print(xrefGraphNode.Name)
            Next
        End Using
    End Sub


[Glenn R]

How do I make this code faster?

Still not learning eh? Ditch COM, especially externally called. That will speed it up by a factor of ~10.

[Glenn R]

BTW, Tim had the right of it.

[cadpro]

FYI I'm working with ObjectDBX. So will Tim's code work?

Thanks

[kdub_nz]

[challenge] for cadpro :

you tell us.


sorry, the debil made me say that !  

[cadpro]

I had earlier reference AutoCAD Type Library and ObjectDBX Library. But since I understand from the post here that my requirements will not work with these references, I changed the reference to acdbmgd and acmgd. Then I tried to access the xref blocks using the 'GetHostDwgXrefGraph', as Tim and ReneRam suggested. But when I call this method, I get an error that says 'The specified module could not be found.' How can I accomplish what I required, by staying outside AutoCAD?

[Draftek]

Dood!

You need to step back and figure out how your hooking into AutoCAD.

Do you know what the difference between the com type libraries and the managed .net libraries is?

A basic understanding of this is going to simplify your coding life. Okay - at least it will be a start.

[It's Alive!]

Unfortunately, if your partying in the .DWG from outside Acad, you're not going to get good performance unless
you are working through RealDWG or are using the ODA libraries.

Are stepping though multiple .DWG files? if so, you might try using Parallel Extensions

[cadpro]

Unfortunately, if your partying in the .DWG from outside Acad, you're not going to get good performance unless
you are working through RealDWG or are using the ODA libraries.

You are right. I realized it just now.

Are stepping though multiple .DWG files? if so, you might try using Parallel Extensions

Could you explain on Parallel Extensions?

I had started off with WPF and the design and coding is complete. Can I change this to dll? This is the code I tried to do.

Code: [Select]

Public Class Class1
    <CommandMethod("Test")> _
    Public Sub showWin()
        Dim winStart As Window1 = New Window1()

        acadapp.ShowModalDialog(winStart)
    End Sub
End Class
But I cannot call WPF form with acadapp. Is this possible in any way?

Thanks

[It's Alive!]

Parallel Extensions help take advantage of multi-core processers, have a look here
http://www.microsoft.com/downloads/details.aspx?FamilyId=348F73FD-593D-4B3C-B055-694C50D2B0F3&displaylang=en

Sorry I can't help you with WPF, I try to stay as far away from WPF as possible 

[Draftek]

You can 'embed' WPF into a windows forms project so you should be good to go there too.

[ReneRam]

Maybe going a little out of topic and getting you strongly relaying on the installed hardware, but take a look at this:

http://www.nvidia.com/object/cuda_home.html#

I have been to workshop with some french nVidia engineers and in my office we're experimenting with this at the moment. Basically with Cuda and Parallel Extensions we're are trying to split the calculation work between the multicore CPU's and the nVidia GPU's :ugly:

[It's Alive!]

Oh man, I do want one of those Tesla C1060 machines. I havn't played with Cuda yet, but I will soon.
Visual studio 2010 has a parallel library for .NET and native C++, unforunatly Acad does not play well with multible threads.

post some samples when you have them 

[It's Alive!]

Woa, this Cuda is cool   

[It's Alive!]

.

[ReneRam]

Daniel as soon as possible, ...

post some samples when you have them

we're on CUDA for it's proper use: GRAPHICS, but what I meant was a little out of the box. With these engineers we talked about other uses. In my company we do a lot of environmental calculus for simulations, and the software's we have make a lot of use of CPU's and RAM, actually one of our softwares, developed in Germany, uses GRID computing, and the work that normally would take 15 days of calculus comes out in 3/4 days. The problem is that if the system stuck ...  you won't know it until the end . We are now thinking and developing our own software that will use Parallel Extensions and CUDA. The idea we came out with was to use the GPU to do some work for us, that is not for the graphic output, OpenGL and Directx have a lot of functions that you can use without getting a graphical output. The same is with WPF, for what I have seen until now, still learning, and maybe I'm wrong, a "paint" method on control in a Windows form makes the whole form drawn, while the same thing done with WPF repaints only the control.
In any case, as soon as I come out with something, you'll see it

[It's Alive!]

.. as soon as I come out with something, you'll see it

Awesome,  I downloaded the CUDA SDK and compiler, going to have a play this weekend.