The first article, “Software Development for Infrastructure” in the January 2012 issue of Computer, is by Bjarne Stroustrop, the inventor of C++. He talks about a number of software issues, but the most surprising to me was his results from a program to add N random integers to a sorted list and then deleting random members of the list. He compared a vector (or array) implementation to a doubly linked list. I would expect the array version to be faster for small N. He tested up to N = 500,000 and the vector implementation was faster with the difference increasing with size. He used a linear search with both implementations, though a binary search on the array would be much faster. Preallocating space for the linked list helped, but the array version was still faster. This I did not expect.

He asked “How do I organize my code and data to minimize memory usage, cache misses, and so on?” His first order answer is:

• don’t store data unnecessarily
• keep data compact
• access memory in a predictable manner

It is the last point where the above example shines.  The linked list is scattered all over memory, the array is alway compact and access patterns predictable.

Two other articles, sorting in C++: 3 times faster than C and Why we didn’t use a bloom filter illustrate that generalizations about programming language speed need to be tested. I think the analysis in the first article of why C++ was faster than C in this case is spot on. I am not convinced that the analysis in the second article is correct, the author has an attitude about the C++ Standard Template Library (STL). He blames Object-Oriented Programming (OOP) and vtables (used in C++ to implement virtual methods). I can think of no good reason to use heavy OOP nor virtual methods in his example. He may have bought into somebody’s dogma of using OOP everywhere and then rightly rejected it as inappropriate and then overgeneralized to rejecting it everywhere. Or may just used just a poor implementation of the STL.

I think his real speedups are coming from a custom solution that exactly matched his problem (the number of elements in a set intersection) instead of the more general solution of computing the set intersection and counting the elements in it. Note: his first solution was to use Redis for this. Convenient, easy, and I could have predicted ahead of time, dead slow. Building sets with millions of elements over the network is slow. Staying in C or C++ is going to be way faster. Beyond that, measure.

Right now (11:25am CST), that talk is gone from the SxSW.com Website. I hope this is a technical glitch.

I e-mailed the developers about the time difference. In reviews, others reported both problems. Waited a day, times still off and sync not working. Uninstalled the app and reinstalled. Times back to correct, still no working sync.

I’ve completed picking the events I want to attend on the SxSW Web site. Now do I mark up the Pocket Guide (paper)? Hand mark up the app? Both?

The Pocket Guide is 8.5″ high, too big for a pocket. And spiral bound. Spiral bindings do not survive long in a pack. But it only needs to last a few days. Paper is dependable.

The Android fits in my bag. Is going anyway. But I don’t know how much I can depend on the app. How mobile friendly is the SxSW Website?

Every year the potholes are in different places. Last year it took three tries and over an hour to get my badge. With a picture from their Web cam at the registration desk. It was never clear why the picture I uploaded was not used. This year I was in and out of badge pickup in under 15 minutes. With the picture from last year that wasn’t acceptable last year. Shrug.

YPMV (Your Potholes May Vary)

Note: introvert is not the same as shy. I’ve met two shy extroverts, both foreign nationals. Two is a bit small sample to generalize from. After a day of meetings, I’m ready to head home for some quiet and sleep. My boss is ready to head over to the local brewpub with the customer to drink and discuss beer. Classic introvert and extrovert behavior. But at the company Christmas party, he is the one standing out around the edges.

I’m about to dive into SxSW Interactive, a potentially overwhelming experience for anyone. Maybe this year I can have a few more successes and a bit less burnout.

gem ‘libxml-ruby’, :require => ‘xml’

I’ve messed with Padrino to check out how to change it for the better. So I’m not positive which changes are the workaround/correction.

Understanding Git Conceptually helped solidify my understanding of Git, especially the section on rebasing. The simple ASCII graphs of the branches and commits make clear what a thousand words did not.

In the process, I read most of the documentation and looked at some example sites.  I picked up on the look and feel  Several sites I’ve visited recently screamed that they were using TW Bootstrap, e.g., linkrdr and others gently hinted, e.g., TEAMSUNITED – Matchmaking.

The conversion wasn’t as hard as I expected. Because more is happening on the client side, I was able to drop some server-side code. A win. And my CSS and Javascript had begun to smell. Now someone else with more experience is writing and maintaining it. Another win.