Thought Palace

Every year the Albums Of The Year lists seem more and more removed from my experience. (Most of the time I haven’t heard a single album on the list.) Worse, we’re now getting into the Of The Decade lists, making me realize how long this has been going on*. If you ask me the top albums of the ‘80s or ‘90s, I don’t have too much trouble rattling off a bunch of names. But this decade? I get confused and have to start thinking hard and looking through the back covers of my mix CDs. Why is that? [Ed.: it’s because you’re getting old. Duh.]

Let me start with this year, 2009. What was good? Hm; my prosthetic brain units at iTunes and last.fm tell me that it’s…

Yes, I’m still working on Ottoman (my append-only multiversion-concurrent storage library). As the code grows in size and complexity, so it grows in its resistance to being changed. But I just pushed my latest changes up to bitbucket.org. What’s new? …

ZSync is a new Mac/iPhone library that uses my BLIP P2P networking protocol.

Farhad Manjoo writing in Slate about Google Wave:

The trouble is, everything you type into Wave is transmitted live, in real time—every keystroke was getting sent to Zach just as I hit it. This made me too self-conscious to get my thoughts across.

… Maybe I should just delete what I’d written and say, “Twitter works because it’s simple.” But I couldn’t do that, because Zach was watching me. He could see me struggling right now—he could see that I’d gotten myself stuck in a textual cul-de-sac and that I was desperately searching for a way out without looking foolish. Now I saw Zach beginning to type: “Don’t let the live-typing get you down!” The game was up; what was the point of making a point now? I ended my thought clumsily and then resolved never to attempt to say anything very deep on Wave.

The same thing happened seven years ago with the live-typing feature that I implemented in iChat 1.0 (which was only supported for Bonjour chats.) I thought it was an awesome idea, and I’d wanted to have it in a chat program since about 1997. But it turned out that, in actual use, people hated it, for exactly the [...]

Ottoman is a lightweight, reliable key-value store with multi-version concurrency control.

A key-value store is a persistent on-disk dictionary that maps arbitrary keys (usually short text strings) to arbitrary values (binary data of any length). There’s already a large and venerable family of libraries that do this, often referred to by the name “db”. Notable members include dbm, Berkeley DB, cdb and Tokyo Cabinet. What makes Ottoman different?

I finally bit the bullet and upgraded to the latest WordPress from the seriously prehistoric version I used to run (I think it was 2.0.4 or something like that.) With the current attacks against older versions, it finally seemed like a worthwhile thing to waste an afternoon on. :-P

Almost everything should work more or less the same. I’ve taken the opportunity to move to a subdomain—jens.mooseyard.com—but the old URLs redirect. The theme is different, because my hacked-up, customized old theme probably wouldn’t have survived the upgrade intact. I can’t say I like this one better, but it’ll do.

The other day I took it into my head to implement a B+tree. Why? Because they sound neat, and I’ve done hardly any serious programming with trees in my career. (Someone, I think Buzz Andersen, once noted that there are two kinds of programmers: those who do think in terms of trees, and those who do everything with hash tables. I’m in the latter camp.)

And also because I’m a big fan of CouchDB, and really admire its elegant storage model. It’s an on-disk B-tree—no surprises there—but the file is append-only, which both makes it impervious to crash-related corruption, provides nearly lockless concurrency, and makes it easy to access earlier revisions.

[In a nutshell: Updated data values or tree nodes are appended to the file instead of overwriting the earlier versions. Since updating a node changes its location, its parent node needs to be updated too to point to the new location. This recurses up the tree, meaning any change ends up with a new root node written at the very end of the file. In fact, when you open the file you find the root by looking at the very end. Since no data is ever changed, once you open the [...]

AppleInsider reports on the iTunes 9 rumors:

“The social networking integration that we reported iTunes 9 would have seems to be part of a bigger social networking push by Apple,” the report states. “We’ve been informed that Apple has plans to tie iTunes 9 into a “Social” application that they plan to release in the future.”

This sounds like the kind of app (though separate from iTunes) that Jessica Kahn and I kept trying in vain to get Apple to build, circa 2003-2005. Maybe they’ll get some use out of our abandoned prototypes.

The report goes on to say that the new application would allow users to share their listening habits with friends [and] send music to friends”

Mike Estee and I had actually prototyped this in iChat in 2003, but the feature never got approved since there were so many more important things to add, like 3-way video conferencing. (Plus the fact that Apple execs turned white as a sheet if you said the words “send music” near them.)

Anyway, personal bitterness aside, I think it’s really amusing that Apple keeps shoving the kitchen sink into iTunes, since that has to be the single nastiest, hardest-to-extend codebase they have — it’s their last remaining [...]

I’ve been working at Google since last August. The Big G’s hiring process is rather weird—when you interview, it’s not for any specific team. It’s only after you get an offer that you decide which team to join, of the ones with open positions.

I decided on Google Sites, which I knew and liked from its days as JotSpot, a hosted wiki with some powerful features. It ended up not being the right place for me, for a couple of reasons:

Currently, Sites’ priorities are in website publishing, as a replacement for Google Page Creator (which is being phased out soon.) It’s quite good at it, but I’m less interested in that than in collaboration features.
Google’s server-side infrastructure is really, really, really huge and complex. There is an endless landscape of internal technologies and tools—the few that have been described in public (MapReduce, BigTable, Chubby, etc.) are just the tip of the iceberg. I have discovered that I am not very interested in this kind of stuff, and I quickly became frustrated by the deluge of technologies I needed to learn to get things done.
Running a large web service is like running a nuclear power plant or an electric power grid. It [...]

I’ve set up a Google Groups mailing-list for Murky, my Mercurial version-control app. It’ll be for both developers and users of the app.

Speaking of “developers”, I’ve been really pleased with the reaction to my initial source-dump to Bitbucket! So far, in nine days:

79 people have subscribed to change notifications;
10 people have forked the repository so they can modify the code;
8 people have contributed to the code, fixing bugs and adding some new features;
39 changesets have been committed to the repository;
29 bug reports and feature suggestions have been filed,
12 of which have been fixed.

I’m especially happy about the patches I’ve received; I’ve gotten some in the past, but never this many or so quickly. Part of this is thanks to Bitbucket, which (like its inspiration, Github) makes it so easy to share code and manage contributions. I’ve been getting more contributions to MYNetwork as well, since hosting it there.

My initial motivation was like Tom Sawyer whitewashing the fence—I was hoping someone else would take over the project, since I’d run out of steam and hadn’t done any work on it in a while. But what happened instead is that the attention got me enthused to work on it again, so I’ve [...]