Time is flying by. The sixth week is nearly over. I hope I didn’t miscounted so far 🙂

This week I made some more progress working on the file transfer code. I read the existing StreamInitialization code and found some typos which I fixed. I than took some inspiration from the SI code to improve my Jingle implementation. Most notably I created a class FileTransferHandler, which the client can use to control the file transfer and get some information on its status etc. Most functionality is yet to be implemented, but at least getting notified when the transfer has ended already works. This allowed me to bring the first integration test for basic Jingle File transfer to life. Previously I had the issue, that the transfer was started as a new thread, which was then out of scope, so that the test had no way to tell if and when the transfer succeeded. This is now fixed 🙂

Other than that integration test, I also worked on creating more junit tests for my Jingle classes and found some more bugs that way. Tests are tedious, but the results are worth the effort. I hope to keep the code coverage of Smack at least on a constant level – already it dropped a little bit with my commits getting merged, but I’m working on correcting that again. While testing, I found a small bug in the SOCKS5 Proxy tests of Smack. Basically there were simultaneous insertions into an ArrayList and a HashSet with a subsequent comparison. This failed under certain circumstances (in my universities network) due to the properties of the set. I fixed the issue by replacing the ArrayList with a LinkedHashSet.

Speaking of tests – I created a “small” test app that utilizes NIO for non-blocking IO operations. I put the word small in quotation marks, because NIO blows up the code by a factor of at least 5. My implementation consists of a server and a client. The client sends a string to the server which than 1337ifies the string and sends it back. The goal of NIO is to use few Threads to handle all the connections at once. It works quite well I’d say. I can handle around 10000 simultaneous connections using a single thread. The next steps will be working NIO into Smack.

Last but not least, I once again got excited about the XMPP community 🙂
As some of you might now, I started to dig into XMPP roughly 8 months ago as part of my bachelors thesis about OMEMO encryption. Back then I wrote a mail to Daniel Gultsch, asking if he could give me some advice on how to start working on an OMEMO implementation.
Now eight months later, I received a mail from another student basically asking me the same question! I’m blown away by how fast one can go from the one asking to the one getting asked. For me this is another beautiful example of truly working open standards and free software.

Thank you 🙂