Performance issues with OPC createRelationship methods

Question

For your project we are planning to use OPC. Our application stores a lot of raw data, each data elements is stored as a seperate part in the OPC file.  The typical size of a part is 32 MB. An OPC file can contain 100 parts, so the file will be quite large (3.2 GB).

To test the performance of the OPC we wrote a simple program, the code for saving the file is listed below:

        private void button1_Click(object sender, RoutedEventArgs e)
        {
             byte[] data = new byte[1024 * 1024];
            // Path and name of the package file.
            string packageFile = @"D:\packaging.zip";
  
            File.Delete(packageFile);

            Stopwatch s = new Stopwatch();

            s.Start();
            // Create and open the package file.
            Package package = Package.Open(packageFile);

            BinaryFormatter formatter = new BinaryFormatter();

            for (int i = 0; i < 100; i++)
            {
                // Create part uri
                Uri partNameUri = PackUriHelper.CreatePartUri(
                    new Uri("/image" + i.ToString(), UriKind.Relative));

                // Create the part.
                PackagePart part = package.CreatePart(
                    partNameUri, "binary/bin", CompressionOption.NotCompressed);

                // write data
                Stream stream = part.GetStream();
                formatter.Serialize(stream, data);
                stream.Close();

                // Create a package-level relationship to the data
               package.CreateRelationship(part.Uri, TargetMode.Internal, "data");
            }
            package.Close();
            s.Stop();
            FileInfo f = new FileInfo(packageFile);
            double fileLength = f.Length / 1.0e6; // file size in Mb)

            Console.WriteLine(s.Elapsed +" data rate: " + fileLength/(s.ElapsedMilliseconds /1000) );
          
        }

When I perform the test I see that the CreateRelationShipMethod has significant impact on the performance:

With CreateRelationShip method: data rate: 13.110676875 MB/sec

Without CreateRelationShip method:  data rate: 26.21953975 MB/sec

I run on Windows XP sp3.

Does anybody know why the createrelationship takes so much time?

Does anybody how to make the createrelationship call performing better?

 

 

Answer 1

Hi M. van Dijk, performance issues are outside of the scope of the Open Packaging Conventions (OPC) forum. Please try posting your question in a forum such as the .NET Base Class Library forum since the Packaging class resides in the System.IO namespace, or the Visual C# General forum for general performance questions. You might also find the information in the following Blog helpful.

 

http://blogs.msdn.com/b/dmahugh/archive/2006/07/15/createxlsx.aspx

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Josh Curry (jcurry) | Escalation Engineer | US-CSS DSC Protocols Team