changelog.txt

This library was based off of David Hammerton's original ZeroconfNetServices.

These are the big changes (made by Robbie Hanson of Deusty.com) from the original code release.

I needed two major changes:

1.) The ability to update TXT records after publishing.
2.) The ability to monitor TXT records for updates.

Here is how I went about making these changes:

The first change was fairly straightforward.  I just needed to be able to call DNSServiceUpdateRecord and pass the updated txt record data.  So to do this I added the proper methods in mDNSImports, and created a setTXTRecordData method to match Apple's documentation.

The second change was a little more challenging.  In order to monitor a TXT record for changes, we need a second sdRef/UnixSocket.  These are stored in DNSService, which both NetService and NetServiceBrowser inherit from.  So I altered the DNSService to maintain an unlimited amount of sdRef's/UnixSockets.  So now the SetupWatchSocket and TeardownWatchSocket methods both take an IntPtr sdRef as a parameter.

Then I added the proper methods to mDNSImports, such as DNSServiceQueryRecord, etc.  And created proper StartMonitoring and StopMonitoring methods.

Other changes, improvements, and bug fixes:

I noticed that the ResolveWithTimeout didn't actually contain a timeout.  So I added timeout functionallity.

While I was studying the mDNSImports file, I kept going back to read Apple's documentation in their header files.  So I ended up copying and pasting a large amount of their comments into mDNSImports.

While I was testing I noticed that resolve operations took a long time.  I only noticed this because I had my Mac sitting right there resolving the same services, and it was doing it something like 3 to 4 times as fast.  Researching this problem, I stumbled upon the following post from Apple explaining the problem, and a solution:
http://lists.apple.com/archives/Bonjour-dev/2006/Jan/msg00008.html

So according to Apple, the solution is to use DNSServiceQueryRecord.  This required another sdRef/UnixSocket.  Which wasn't a problem, since I'd already configured DNSService to maintain multiples.  So I altered the post resolve IP lookup stuff, and now it works just as fast as on Mac!

In the original code, in NetService.Stop() there was:
/* FIXME: do i need to stop the poll? */
Essentially, the answer is NO.  However, there was a small bug nearby which may have caused frustration.  The code basically looked like this:

void AsyncPollCallback(...)
{
  if(stopping)
  {
    // Don't do callback because we're stopping
    return;
  }
  // Do callback
  // Start another poll
}

BUT, if the user calls Stop from the callback method, then another poll is started when it shouldn't be.

Other notes:

Altered DataFromTXTRecordDictionary to accept a null argument. This is helpful to allow one to quickly create an empty TXT record.

Altered DataFromTXTRecordDictionary to allow either a byte[] or string as a value in the dictionary argument.  This makes it easier for programmers to make TXT records.  Plus, Apple's NSNetService works fine with a dictionary containing string values.

Previously, DNSService contained the variables inPoll, stopping, and sdRef.  In order to allow DNSService to maintain multiple sdRef's, I extended UnixSocket, and placed these variables in the extended class.  This is in the UnixSocket file, and the class is called WatchSocket.

And of course:

Updated BrowserServiceSample to reflect new capabilities.
Updated PublishServiceSample to reflect new capabilities.


Ongoing changes will not be reported in this text file. Instead, consult the subversion repository changelog.