Slacy’s Blog

I’m downloading more and more stuff from Amazon’s MP3 service these days. The big driver was actually their “deals” twitter feed that can be found at http://twitter.com/amazonmp3

They advertize daily (and weekend) album deals for between $2 and $5 per album. If the average album has 12 songs, then this is between 17 and 42 cents per song, which is seeming really reasonable to me, and at the low end, is cheaper than my current eMusic subscription of 90 songs for $20, or 22.2 cents per song.

The best part is that with Amazon’s large DRM-free collection, I don’t have to agonize about not being able to find what I’m really looking for. That convenience alone is worth something, and isn’t it worth paying a little more for music you really want instead of getting cheap music that you don’t want?

(NB: My cast few batches of eMusic have had some really great stuff, so I’m not really complaining, but I am feeling more and more like I’ve exhausted their collection)

We hired a great photographer to come by our place and take some photos of Isaac just after his 1st birthday…

In case you were wondering what the plans for the Kitchen Remodel were. We (accidentally?) got an electronic copy today, and I’ve cropped out the interesting section so you can see it below. I’m sure you don’t really want a 10,000×8,000 pixel image, right? Almost everything you see in that drawing other than the existing bathroom is new construction.

As usual, click to enlarge.

Okay, so as you know, our kitchen is being remodeled. What this means is that we’re still having periodic power outages at home when they’re doing construction, and that means that slacy.com might not be accessible 100% of the time.

The kleinlacy.com gallery will always be up, and I’m going to really start getting motivated on moving stuff like the slacy.com/blog to the hosted server as well…

Sorry!

I’ve put up all the photos from Switzerland, and there are too many to count, so you’ll have to go take a look yourself. Here are some samples. Click to head to the full album(s).

Everybody wants to see pictures, right?

I’ll be adding on to that album as time goes on.

Take a look at this short python script:

#!/usr/bin/python

from sys import stdin, argv

outputs = []
numargs = 0
for arg in argv[1:]:
  outputs.append(open(arg, 'a'))
  numargs += 1

s = "str"
counter = 0
p = 0
while len(s) > 0:
  s = stdin.read(32 * 1024)
  p = s.rfind('\n') + 1
  if p > 0:
    outputs[counter % numargs].write(s[:p])
    counter += 1
    outputs[counter % numargs].write(s[p:])
  else:
    outputs[counter % numargs].write(s)
    counter += 1

It does the file interleaving task that I’ve talked about previously, and does it reasonably fast. Its a reasonable replacement for the C++ version, and can rip through a ~600MB file in about 0.75s.

I’ve been playing with a simple wrapper script for executing parallel sorts, like this:

#!/bin/bash
rm     a b c d e f g h i j
mkfifo a b c d e f g h i j

cat $1 | interleave.py a b c d &

sort -S 25% a -o e &
sort -S 25% b -o f &
sort -S 25% c -o g &
sort -S 25% d -o h &

sort -m e f -o i &
sort -m g h -o j &
sort -m i j

Which does a 4-way parallel sort, and then a 3-way parallel merge of the resultant sorted data. (Yes, doing a parallel merge actually makes things a little faster). It uses unix FIFOs instead of keeping the temporary files on disk, which saves a lot of I/O of writing and reading the temporary files.

This code can sort a ~600MB file in 25.1s, whereas a vanilla unix ’sort’ command on the same data takes 34.7s, so I’ve got a speedup of about 35%. That’s pretty good, when you think that the maximum possible speedup is 50%.

Hi, we’re back from our 2 week trip to Switzerland, and I’m sorry for the blog & website outage.

While we were away, they started construction for our new Kitchen, and that means that I had to hastily disassemble our networking closet, and that meant that I lost all connectivity to slacy.com.

Anyway, I’m still meaning to migrate the whole thing over to the new hosted server (like I did with the gallery, which was still up the whole time on kleinlacy.com/gallery) but I just haven’t had the time to sit down and do that.

What you really want to see is pictures from the trip, right? They’re still stick on the CF cards in the camera, so you’ll have to wait.

Oh, and there are pictures of our demolished kitchen in there as well.

Patience!