MacKuba

There are many posts and articles that compare available open source licenses. A lot of them aren’t objective and are biased towards some kinds of licenses based on author’s own preferences.

Well, I have to disappoint you, this one isn’t going to be any different :)

After the VLC incident last week I got kind of fed up with GPL. I had licensed a few of my projects under GPL before, but I decided I don’t want to use a license that’s so restrictive that it makes it impossible to put an app on AppStore, even if it’s shared for free and the source code is available. So I did some research to find what other licenses made sense for me. As usual, I spent way more time on this that I should have, and the notes below are the result. (Note that I haven’t actually read the whole text of most of these – I’m not that crazy.)

Update (6.07.2017): I’ve added a section below about the “Very Simple Public License” (VSPL) that I started using in my projects as a simpler replacement for MIT.

A few months ago I wrote a post about JSON parsing libraries for Cocoa. I compared 4 libraries – BSJSONAdditions, JSON Framework, TouchJSON, and YAJL, I ran a benchmark on all of them, and the conclusion was that YAJL was the fastest and BSJSONAdditions was way slower than the rest.

Last week John Engelhart commented on that post, mentioning his own JSON library JSONKit, claiming that it’s really fast. Of course I had to check if that was true :)

Ever since I started coding in Cocoa, I’ve been wondering what might be the longest name used for any function or constant in the entire API. Cocoa names can get quite long in general, so the longest one should be really ridiculously long… Of course I couldn’t leave it like this and I had to find out what it was :)

I ran a search for *.h files on the whole disk, and I determined that the interesting stuff was either in /Developer or in /System/Library/Frameworks, so I limited the search to these directories only. I passed the list of all header files through a Ruby script that looked for the really long ones and sorted them by length, and then I analyzed the results to find the winners (I decided to divide them into a few categories).

So here’s what I’ve found:

This week I went to Berlin for 2 days to attend the MongoBerlin conference organized by 10gen, the creators of MongoDB. I took a lot of notes from the presentations, and I figured this may be useful for someone if they missed a presentation (or just couldn’t go to the conference).

Feel free to correct me if I got something wrong :)

Update: A new post from December 2010 with updated stats is available here.

For a few weeks I’ve been working on a new iPhone application.

Like most of other Cocoa apps I’ve written so far, this app also includes a JSON parser to load some kind of data from a server. The first thing the application does when it starts is connect to the JSON API, download a data file (about 100 KB) and parse it. This used to take about 10-15 seconds on the device, and I thought it was reasonable until I noticed that the HTTP response actually arrives after a second or so. So what was it doing for the rest of the time? I had to find out.

So I did some debugging, and it turned out that the 10 seconds are spent just on parsing the downloaded JSON file. That’s pretty bad… Like in all previous apps, I used an open source library BSJSONAdditions, which I knew wasn’t the fastest one available, but I never had any major problems with it before. On the other hand, I never tested it on a 100 KB file…

I knew there were a few other JSON parser libraries in ObjC, so I decided to make a small benchmark and see how well they all compared to the one I used. The other libraries I tried were: JSON Framework, TouchJSON and YAJL.

I’m working on a new version of this blog, in which I want to use RightJS. This week I wanted to add some kind of pretty JavaScript tooltips there; there is a Tooltip class in RightJS, but I don’t like the way these tooltips look. However, I know a jQuery library called “TipTip” which adds very attractive black tooltips. So I took the TipTip code and rewrote it using RightJS (and renamed to RipTip, for obvious reasons) – code is available on GitHub, as usual.

This is how the tooltips look:

I came across a problem recently. I have a project called xBlip which I’ve described before – it’s an iPhone client for a Polish Twitter-like service Blip. This project has a backend part which I keep in a subdirectory “ObjectiveBlip” and which I’ve tried to keep as separate from the rest as possible, with the intention that it might be one day extracted as a separate project.

Now I got the idea that I could write a desktop application for Mac that does the same – and of course I could reuse that backend part for that. I would also like to create a separate project on Github with just the backend, so that theoretically someone might use it in future for some purpose.

But this means that I would be maintaining three separate copies of the same code, which I’d have to keep in sync somehow. So the question is, how to do this best?

There are a few ways in Git to share code between projects (for example, git submodules) – but most of them are intended only for one-way communication, i.e. downloading updates to a library maintained by someone else into your project. Here, I want to have a two-way communication: I could extend the backend code while working either on the iPhone or the Mac application (working directly on the backend-only project wouldn’t usually make sense), and then broadcast the changes into the other two projects. I also don’t want the solution to be inconvenient to people who download the project, as is the case with git submodules – you have to manually update them once you download the main code, initially their directories are empty.

So I started looking for a way to pull this off – and I found a script called “git subtree” which seems to do exactly what I need (confusingly, there’s another plugin also called git subtree which is completely unrelated to the first one…). It took me some time (and a few emails to the author, Avery Pennarun) to figure out how to use it, so I thought I’d post a tutorial here in case anyone has a similar situation.

So, here’s what we need to do… (grab a coffee, it’s going to be long):