Question

I have a simple application that retrieves a dataset from the database and converts it to an xml file. This xml file is then read in and compressed to a .gz file.

This seems pretty inefficient – is it possible to skip the step of writing to a temporary .xml file and reading it back into compress it? Can I automatically send the file to a stream which converts it directly to a converted xml format?

Here is my code:

public partial class _Default : System.Web.UI.Page
{
    DataSet dataset = new DataSet();
    string uri = "C:\\tester.xml";
    string compressedfileuri = "C:\\tester.gz";

    protected void Page_Load(object sender, EventArgs e)
    {            
        //get the dataset
        RetrieveData();

        //serialize data to a xml file
        dataset.WriteXml(uri);

        //compress the data
        Compress();
    }

    public void RetrieveData()
    {
        string connString = ConfigurationManager.ConnectionStrings["Platform"].ConnectionString;
        using (SqlConnection conn = new SqlConnection(connString))
        {
            SqlDataAdapter adapter = new SqlDataAdapter();
            adapter.SelectCommand = new SqlCommand("SELECT * FROM expenses.CST_COSTHEADER", conn);
            adapter.Fill(dataset);                
        }
    }

    public void Compress()
    {
        using (FileStream fs = new FileStream(uri, FileMode.Open))
        {
            using (FileStream outFile = File.Create(compressedfileuri))
            {
                using (GZipStream Compress = new GZipStream(outFile, CompressionMode.Compress))
                {
                    fs.CopyTo(Compress);
                }
            }
        }
    }
}

Answer 1

Why just not use following overload and write directly to ZIp stream?

DataSet.WriteXml Method (Stream, XmlWriteMode)

public void WriteXml(
    Stream stream,
    XmlWriteMode mode
)