42 karma · joined January 25, 2014
One property of the Fourier transform is that convolution in the time domain corresponds to element-wise multiplication in the frequency domain (https://en.wikipedia.org/wiki/Convolution_theorem), so you can compute the convolution efficiently by taking the FFT of both series, doing element-wise multiplication, and then taking the inverse FFT of the result.
$ time xz linux-4.14-rc6.tar
real 4m26.009s
user 4m24.828s
sys 0m0.724s
$ wc -c linux-4.14-rc6.tar.xz
103705148 linux-4.14-rc6.tar.xz
$ time zstd --ultra -20 linux-4.14-rc6.tar
linux-4.14-rc6.tar : 12.81% (824350720 => 105564246 bytes, linux-4.14-rc6.tar.zst)
real 4m34.129s
user 4m33.484s
sys 0m0.432s
$ time cat linux-4.14-rc6.tar.xz | xz -d > out1
real 0m9.677s
user 0m6.608s
sys 0m0.704s
$ time cat linux-4.14-rc6.tar.zst | zstd -d > out2
real 0m1.702s
user 0m1.220s
sys 0m0.520s
[0]: https://github.com/facebook/zstd/blob/dev/doc/images/DCspeed...> Everyone who is born in Canada is eligible for Canadian citizenship, with one exception: those who are born to employees of foreign governments.
While the Ontario debt is larger than the California debt, it's not really a fair comparison.[1][2]
And on the communist state bit, uh what?
[1]: http://www.thestar.com/opinion/commentary/2014/03/21/ontario... [2]: http://blogs.wsj.com/canadarealtime/2014/03/18/ontario-debt-...
On the crypto side of things, are there any plans to create native clients? While I don't doubt that you guys are trustworthy, it would be nice if I didn't have to trust that the javascript I was being served didn't change between visits.
All in all it looks good, albeit with some trust issues...
In any case, I believe he was joking. The odds of a sha1 collision are very very low.
would be more appropriate