deect.com - pre-beta release

Based on the feedbacks we have received in the last month, I've just released a new version of deect.com, our multilingual dictionary. Major news in this release:

• new user interface, with Hungarian localization
• a bit larger language corpus (English-Hungarian dictionary)
• autocomplete for the searches
• fine-grained searches (accent-sensitive, case-sensitive, prefix and full matches)

We are looking for feedback, if you like it or if you have any kind of comment, suggestion, please let us know.

The user interface is entirely written in Apache Wicket. I just need to mention how easy it was to apply protection against Cross-site Request Forgery attack, while we have preserved bookmarkable pages at full strength. Wicket is just too good for this job, and we will definitely blog about the techniques we have used.

Multilingual dictionary + lexicon = deect.com

I'm happy to invite everyone to test drive our new product: deect.com is a multilingual dictionary, merged with a lexicon. It is in a very early stage at the moment:

• read-only, limited functionality,
• contains only 550.000+ words from WordNet and Wiktionary,
• not really fast (running on the smallest Amazon EC2 instance).

However, it does show the concept, which might help to create better online dictionaries, language learning services or translation automation system. Please help us, give us early feedback!

Profiler microkernel - contribute your idea

We have been busy with various projects and assignments lately, but let's say a few words about the profiler.

Aron Deak is working on the network profiling part and he is doing a promising job on it, we really look forward to see the results, and we will release it as 1.2.

As a separate work we are doing some (scientific) research on general application profiling, various profiling strategies and data structures that could help us to do these profiling even better. To achieve that, we will build a profiler microkernel that satisfies both our research need and in the same time it helps our users to. We are open to receive any idea or feature request that would help you or something that you think is not really convenient at the moment.

So far, we have collected the following features:

• control over the profiler in general (start / stop / schedule / trigger profiling)
• control over the output (local file, network client)
• control over the periods of various samplers
• monitoring and alerting service
• late-instrumentation of classes (e.g. class hot-swapping)
• parameter-level instrumentation, sampling and interception
• .... (who knows? :) )

Okay, this is a pretty nice list, but we are determined to get this working, sooner or later - depending on other workloads. So if you need something to add to this list, just send us a mail or leave a comment here.

OKTECH Profiler 1.1

After a lot addition, we are happy to release OKTECH Profiler 1.1. It has been a very busy period for us, lots of education and consulting, but in the end we have managed to release it only with a week delay.

New features:

• Instrumentation profiler using Javassist
• Method summary for tree report
• XML output format for tree report
• Configurable timer (nanotime / thread cpu time)

We have extended the documentation, it is much more detailed now. You might expect tutorials and howtos in the near future, and of course if there is any feature you are interested in, just let us known or open a new issue on the project page.

And last, but not least, we are happy that Aron Deak from the Budapest University of Technology and Economics has joined us for at least this semester - he is now investigating the network profiling options, hopefully it will be a great contribution to the profiler.

Comma separated list: CSS or application code?

Recently I've encountered a problem of displaying comma-separated list items on a web page. It came natural to check if it can be done in CSS or not. This page explains the concept implemented in CSS, and on this example page you can check it yourself. It works in Safari and Firefox, but does not work in IE 7 - it just don't display any comma at all, the items are listed with spaces between them. Too bad :(

That will leave us t0 implement the comma separated list inside the application, in our case: in Wicket. The following small code fragments explain the basic idea:

<wicket:container wicket:id="list">
<span wicket:id="comma"> </span>
<span wicket:id="label">some value</span>
</wicket:container>

We created a container without markup; inside the container we have defined a "comma" component, and a "label" component. If we take a look at the Java code, it is pretty easy to understand how it goes, actual code fragment uses ListView:

        add(new ListView<String>("list", new MyListModel(myParentModel)) {

       private static final long serialVersionUID = 1L;

       @Override
       protected void populateItem(final ListItem<String> item) {
           item.add(new Label("comma", ", ") {

               private static final long serialVersionUID = 1L;

               @Override
               public boolean isVisible() {
                   return item.getIndex() != 0;
               }

           });

           item.add(new Label("label", item.getModel()));
       }

   });

The first comma component is not shown, while all the others are. It is really simple to implement - after you have the idea and design. Of course you might get rid of the <span> elements too, if that makes sense in your application.

DataOutputStream: encoded string too long

As I'm preparing to release OKTECH Profiler 1.1, I have checked the performance benchmarks on the profiler itself. It came apparent that the UTF-8 conversion consumes a lot time, so I've started to investigate what happens behind the scenes. I've encountered a little shock at the DataOutputStream class: it has a serious limitation, as it doesn't allows to write strings larger than 64k. I thought those times(*) were over and it is just the Java reference source code that has this limitation, so I've written a small program to double-check it:

    public static void main(String[] args) throws Exception {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 10000; i++)
            sb.append("1234567890");
        String s = sb.toString();

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(baos);
        dos.writeUTF(s);
        dos.close();
    }

(*) I got lazy in Java and assumed that it just works.

To my great dislike, it fails on my Mac, the DataOutputStream does have this 64k limitation. Having an other look on the Javadoc, it does contain this limitation. At the moment this shouldn't affect OKTECH Profiler, as I cannot imagine any stacktrace that has a method or class which is longer than that.

On the other hand, we are now in a process that ensures larger flexibility in the dumps, allowing 3rd party plugins easier to be contributed in the profiler runtime and analysis. After this experiment, I'm considering a more XML-like dump format, e.g. Fast Infoset, a pretty good binary xml format. (Update: no, it won't be binary XML, it is so much slower than pure DataOutputStream).

OKTECH Profiler @ Java User Meeting, Budapest

It is good to see and notice the interest in OKTECH Profiler. In Budapest, we have a roughly bimonthly Java User Group meeting, and this time I had participated to give a little presentation on OKTECH Profiler. Unfortunately because our actual project assignments just burn our time, I had not prepared everything I wanted, especially the release of 1.1 version, but still, the presentation had been received fine.

You can download it here in pdf. There is no downloadable demo yet, but please be patient, we are working on the 1.1 release's documentation and will do an other presentation in just two weeks. In the next two weeks, I'd like to release the 1.1 version with solid documentation, prepare a sample of an analysis and document the findings. In the meantime you might check the source codes from the Subversion repository...