Question

I have a DataSet consisting of XML data, I can easily output this to a file:

DataSet ds = new DataSet(); DataTable dt = new DataTable(); ds.Tables.Add(dt); ds.Load(reader, LoadOption.PreserveChanges, ds.Tables[0]); ds.WriteXml('C:\\test.xml'); 

However what I want to do is compress the XML into a ZIP or other type of compressed file and then just save this file to disk while splitting the ZIP file into 1MB chunks. I do not really want to save the uncompressed file, and then zip it, then split it.

What I’m looking for specifically is:

1. a suitable compression library that I can stream the XML to and have the zip file(s) saved to disk
2. some sample C# code that can show me how to do this.

Answer 1

I’ve managed to compress a DataSet’s XML stream using .NET 2.0’s gzip compression.

Here’s the blog post I made a few years ago about it:

Saving DataSets Locally With Compression

… and here’s the code I added to my DataSet’s partial class to write the compressed file (the blog post has the reading code too):

public void WriteFile(string fileName) {     using (FileStream fs = new FileStream(fileName, FileMode.Create))     {         Stream s;         if (Path.GetExtension(fileName) == '.cmx')         {             s = new GZipStream(fs, CompressionMode.Compress);         }         else if (Path.GetExtension(fileName) == '.cmz')         {             s = new DeflateStream(fs, CompressionMode.Compress);         }         else         {             s = fs;         }         WriteXml(s);         s.Close();     } }  

Note that this code uses different compression schemes based on the file’s extension. That was purely so I could test one scheme against the other with my DataSet.