Net.WebClient and GZip

The Net.WebClient class doesn't support HTTP compression, eg, when you add the Accept-Encoding: gzip,deflate header to your request:

Dim wc As New Net.WebClient
'-- google will not gzip the content if the User-Agent header is missing!
wc.Headers.Add("User-Agent", strHttpUserAgent)
wc.Headers.Add("Accept-Encoding", "gzip,deflate")
'-- download the target URL into a byte array
Dim b() As Byte = wc.DownloadData(strUrl)

What you get is a gzipped array of bytes. It's pretty easy to add the missing gzip support, though. First, download the SharpZipLib and add a reference to ICSharpCode.SharpZipLib to your project. Then it's only a few more lines of code..

Dim gz As New GZip.GZipInputStream(New MemoryStream(b))
Dim intSizeRead As Integer
Dim unzipBytes(intChunkSize) As Byte
Dim OutputStream As New MemoryStream
While True
'-- this decompresses a chunk
'-- remember the output will be larger than the input (one would hope)
intSizeRead = gz.Read(unzipBytes, 0, intChunkSize)
If intSizeRead > 0 Then
OutputStream.Write(unzipBytes, 0, intSizeRead)
Else
Exit While
End If
End While
'-- convert our decompressed bytestream into a UTF-8 string
Return System.Text.Encoding.UTF8.GetString(OutputStream.ToArray)

And voila, the bandwidth, you have saved eet! How do I know this actually works? Using my network sniffer of course..

Read more

Stay Gold, America

We are at an unprecedented point in American history, and I'm concerned we may lose sight of the American Dream.

By Jeff Atwood · · Comments

The Great Filter Comes For Us All

With a 13 billion year head start on evolution, why haven't any other forms of life in the universe contacted us by now? (Arrival is a fantastic movie. Watch it, but don't stop there - read the Story of Your Life novella it was based on

By Jeff Atwood · · Comments

I Fight For The Users

If you haven't been able to keep up with my blistering pace of one blog post per year, I don't blame you. There's a lot going on right now. It's a busy time. But let's pause and take a moment

By Jeff Atwood · · Comments

The 2030 Self-Driving Car Bet

It's my honor to announce that John Carmack and I have initiated a friendly bet of $10,000* to the 501(c)(3) charity of the winner’s choice: By January 1st, 2030, completely autonomous self-driving cars meeting SAE J3016 level 5 will be commercially available for passenger

By Jeff Atwood · · Comments