psi-squared

6 ms·

1.
by psi-squared 9y ago
That's a really neat solution, and avoids the cognitive overhead of having to remember yet another password (or the security risk of re-using passwords). I particularly like the way you tie the log-in token to a particular browser sess
2.
by psi-squared 9y ago
It's worth noting that, if you need something which runs on really low power, ARM have their R and M series processors. So even if the A series did become really power-hungry, the other two lines presumably wouldn't.
3.
by psi-squared 9y ago
> I suspect the results in this paper could be improved with more modern gather techniques on newer x86-64 processors. By that, do you mean the AVX2 'gather' type instructions? If not, I'd be interested to know what those
4.
by psi-squared 9y ago
If you want exactly zero at the end points, you could do something like the post does, of approximating sin(x) / x(pi+x)(pi-x), or similar. You can still do that with the Remez algorithm. Also, a while ago I realized that you can tweak
5.
by psi-squared 9y ago
The paper has a section on this, around the end of page 4, which is really interesting. The short version is: They compared their double-precision results to extremely high-precision Taylor expansions (with theoretical 70+ digit accuracy, a
6.
by psi-squared 9y ago
I am not a security researcher, but I think you could keep the benefits of both compression and security, as long as you're careful on the server side: Say you have a document structured like [boring data] [secret data] [boring data].
7.
by psi-squared 10y ago
I had an eye test recently (in the UK, if it's relevant), and they had a device which seemed to do that. You sit down, look into the device and see a blurry image, which sort of "snaps" into focus as it works out the shape of
8.
by psi-squared 10y ago
This is related to my current favourite algorithm: Because the BWT is closely related to the suffix tree of the original string, there's an algorithm to search for a substring of length 'm' in a BWT-ed string of length '
9.
by psi-squared 10y ago
There's a really nice article about the Postgres query optimizer, which goes into much more detail about the algorithms used (it's likely that at least the basic ideas are shared with SQL server, though I can't say for sure).
10.
by psi-squared 10y ago
Okay, so on reading through that it looks like the answer to my question is "it depends": * On-disk, the layered approach always saves space, as expected * In memory, it depends on which storage backend you use: apparently btrfs c
11.
by psi-squared 10y ago
(disclaimer: I haven't watched the talk yet, this is just branching off of Animats's comment) One thing I wonder, and which I don't know enough about containers to answer myself, is: Let's say I have a bunch of container
12.
by psi-squared 10y ago
It looks like the first part of what you want is nearly there - see https://github.com/Yamakaky/rust-bindgen It converts C headers to a Rust module containing the relevant type/function/etc. definitions. On s
13.
by psi-squared 10y ago
One of the less-well-known features of Linux is that you can do this! Theres's a thing called the "x32 ABI" (use the option -mx32 with gcc or clang; you'll need all your libraries compiled with it too) where: * As far as
14.
by psi-squared 10y ago
(edited to add: Note that superoptimization isn't something you do to a whole program, it's more a thing you do to speed-critical sections of a larger program, ideally on the order of a few dozen instructions at most. That alone m
15.
by psi-squared 10y ago
My current workflow has a lot of "Run make -j<lots> to build, followed by parallel -j<lots> to run all the tests", but sometimes I want to compare/test multiple different versions of the code (in a way which, sadl
16.
by psi-squared 10y ago
If I've read this correctly, the 'sem' mode lets you submit several lots of jobs with an overall limit on the total number of tasks running at a time (rather than one limit per lot of jobs). That on its own is super useful fo
17.
by psi-squared 10y ago
This is pretty neat! A couple of thoughts spinning off from this: In the breadth-first traversal example, it looks like the resulting linked list is completely static. By that I mean that you could pre-compute the traversal order and store
18.
by psi-squared 10y ago
It's been mentioned below that differences in temperature matter a lot. But there's also the fact that erasing a flash block inherently damages it, progressively reducing its ability to retain data. So I wonder if there's a t
19.
by psi-squared 10y ago
The two types of "ghosts" here are very different. In both cases, though, they're mathematical artefacts rather than anything "physical", but I'll try to explain them as well as I know. Disclaimer: The most adv
20.
by psi-squared 10y ago
So, let's call the correct value of whatever 'A'. Then "Off by X%" really means that the number you used is (1 + X/100) * A. (note: if you underestimated you need to make X negative for this to work) When you r
21.
by psi-squared 10y ago
There is an exception-like mechanism in Rust, in the form of the "try!" macro. It's a lot more flexible, but somewhat more verbose (Haskell has the same mechanism in a way that looks a lot more like exceptions, so that&#x27
22.
by psi-squared 11y ago
As the article points out, every modern OS clears (main) memory before handing it over to a new process. The cost is often mitigated a bit by using spare CPU cycles to zero out free pages, and by keeping a buffer of such pages. You only nee
23.
by psi-squared 11y ago
AIUI, ZFS was explicitly designed to deal with this sort of data corruption - one of the descriptions of the design I've heard is "read() will return either the contents of a previous successful write() or an error". That wou
24.
by psi-squared 11y ago
How much do you cache? Hardware is difficult because you could add/remove/swap it at any time, and software information is already partly cached depending on your OS. IIRC, Windows a) builds a list of files to pre-load from disk b