internal fragmentation

a personal journal of hacking, science, and technology

Walter Gordon Heffron

Tue, 30 Jun 2009 22:09 by mpm in Uncategorized (link)

My grandfather passed away earlier today. Thinking back, it amazes me the degree to which he set the foundation for my later pursuits and hobbies: astronomy, physics, mathematics, electronics, computing.

He was a researcher for many decades at Bell Labs. He was intimately involved with the Apollo program, not to mention countless other efforts ranging from sonar to the invention of videoconferencing. He was there for the invention of the transistor.

He was colorblind (a trait he passed to me), but memorized the colorblindness eye charts in attempt to qualify for the astronaut program. He taught me the names of the constellations. And he took me to see Star Wars in the theater.

He also introduced me to Unix via a home-built VT52 terminal that dialed into a server at Bell Labs, the birthplace of Unix. I spent countless hours exploring; I retrieved the Amulet of Yendor at age 7. Not long after that, he sent me a first edition copy of The C Programming Language, also created by his coworkers. I quickly read it cover to cover, despite having no access to a C compiler. Thirty years later, I’m hacking the Linux kernel in C.

I saw him for the last time a couple weeks ago. I showed him the bash shell prompt on my GPhone, a machine thousands of times more capable and portable than the machines he introduced me to, and running a version of Unix I’d helped develop.

Coming Soon!

Thu, 18 Jun 2009 18:55 by mpm in mercurial (link)

Looks like Mercurial: The Definitive Guide has finally hit paper. Looks like it’s set to ship to coincide with Mercurial’s planned 1.3 release on July 1st.

Steve Case

02:50 by mpm in Uncategorized (link)

Before I caught the free software fever, I spent most of a decade working on laser and imaging-based measurement. And I had the fortune of spending that time working with an incredibly talented group at a small company called CyberOptics. At every place I’ve worked since, I’ve always been a little disappointed that the local talent didn’t quite measure up to their level.

The founder of that company was Steve Case, a professor of optics turned entrepreneur. Today I learned he died in a solo plane crash. He was a good guy.

Mercurial on BigTable

Mon, 15 Jun 2009 03:34 by mpm in mercurial (link)

Also worth mentioning there’s now video for the recent Google I/O talk on adapting Mercurial to BigTable. A pretty decent introduction to both Mercurial internals and their BigTable technology (see Hbase from the Hadoop project for an open alternative).

Shared Repos and Subrepositories

03:19 by mpm in mercurial (link)

With less than a week before Mercurial’s 1.3 code freeze, I’ve pushed two interesting new features. The first is the share extension which can be thought of as an even lighter-weight local clone. The core support for this has been in place for years now (since 0.9.2), we’d just never gotten around to making it available as a command.

Also, Mercurial now has support for subrepositories which is a way to automatically pull other projects such as libraries into your working directory as part of a larger project. Commits made at the top level repository will recursively record the state of the subrepos, effectively allowing atomic commits across multiple projects.

I’ve also managed to design the code in such a way that it should be quite easy to extend this to support subrepositories from other systems like SVN or git.