OSX + Parallels Desktop + Windows keyboard

I just bought a Windows keyboard to help with my coding(and gaming) but as you can imagine, not everything went without a hitch. In particular, I had troubles with the Command and Option keys due to my muscle memory of working with a mac for so long :)

Using the OSX default keymapper simply didn't work, since there you could only map Command (both) to Option and vice versa. And if you did that, the AltGr inside Parallels Desktoip Windows stopped working (and although you could map them back in Parallels Desktop, it was the same issue there, you mapped both left and right keys as one!)

The solution was to use Karabiner, formerly known as KeyRemap4MacBook. In there you could distinguish between left and right keys!

So I mapped Command Left to Options Left and vice versa, but now I had the issue of it not working in the Windows VM. Then I installed SharpKeys, which could do the same, map the keys back!

So now I have a working setup for both OS'es, and if I find a new issue, I'm pretty confident these two programs can solve that.

Install SSH server on Windows 7

Since I don't want to maintain several Parallels Desktop VM's on each of my machines (due to disc space and maintenance), I need to be able to ssh into them, but also use the same shared folder where I have my code.

Bitwise SSH Server

When googling for windows ssh servers, the majority of the answers were pretty old, but I didn't really mind that as long as they worked ok. I tried installing OpenSSH via cygwin (which was easy), but that gave me a cygwin prompt which didn't have all my user's environment variables and it also behaved erratically (and occasionally hung). I also looked into using the freeSSHD, and that had a nice UI to change settings and add users. But it just never let me log on (Access Denied), despite trying all the tricks google gave me.

In the end I limited my searches for the latest year, and at the top it suggested the Bitwise SSH Server. It's free for personal & non commercial use and it was really easy to setup. Run the installer, and then add a user in the UI settings. Et voila! Everything worked out of the box!

Shared Network Folders

The setup I have is that I have my code on my MBP, the Windows VM on an iMac. So I want to login in to the VM, and there I want to compile my code using MSVS.

Parallels Desktop is good at sharing Mac & Samba folders with the VM, but my problem is still with the ssh login: It cannot access the mapped drives!

If I run $> net use the drives are there, but I can't cd into them! They're listed as "Network: Parallels Desktop Folders" and their "status" fields are empty.

However, when I run $> net use L: \\10.0.1.42\shared /user:MACBOOKPRO-AB12\mawe the drive mounts nicely (after password confirmation). And fortunately, the Bitwise ssh server remembers mapped shares by default (if they're mapped as Microsoft Windows Network) so the next time you log in, the drive is still there.

Yay!

I've heard about the SSH server issues on windows before, but with such a great tool, I definitely think those days are gone. I am now a happy multi platform coder again!

xxHash64 - a fast 64 bit hash function

In my work I often use various hash functions as hashes or checksums, and it's always beneficial to know about different qualities and speed of the functions available.

Yann Collet (known for the LZ4 compression algorithm) has now updated his xxHash algorithm with a 64 bit version, and it's speed is quite excellent. On my machine, a 64bit MBP @ 3GHz:
xxHash64            - ~13.5 GB/s
CityHash128         - ~12.5 GB/s
CityHash64          - ~11.5 GB/s
MurmurHash3_x64_128 - ~5.5 GB/s

The function has been tested against the smhasher suite, and passing all tests. Although the tests are more geared towards 32 bit hashes, the well known MurmurHash3 function is also tested against this suite.

The XXH64 is implemented mainly for 64 bit platforms, so it's performance is not as good on 32 bit systems. But then you probably would use XXH32 anyways.

I'm sure more tests will reveal more of the hash quality in the future.

For code and speed comparisons, check it out at https://github.com/Cyan4973/xxHash

Installing Parallels Tools on Debian 7

This entry is about remembering how I solved this issue (as well as boost some traffix for the blogger that solved it)

Parallels Tools is a package designed to make various host/guest tools work: Clipboard, shared folders etc.

For some reason though, the Parallels' way of installing it fails. And it turns out to be a mount + security problem.

First off, the iso wouldn't mount when choosing the "Virtual Machine -> Install Parallels Tools". So I had to manually find it using the "Devices -> Cd/Dvd -> Connect Image..." and browsing to "/Applications/Parallels\ Desktop.app/Contents/Resources/Tools/prl-tools-lin.iso"

But, it still wouldn't work. So, after some googling I followed this guide: Install Parallels Tools on a Debian Virtual Machine

In short these commands (on the guest) solved the issue once I got the iso mounted:

Eclipse + SSH

I work a lot across multiple systems of various OS'es and configurations, and usually I do it via ssh. However, almost everytime, the tasks get much slower than they ought to be, due to the fact that the remote system doesn't have your local tools and configs.

Since I mostly use Eclipse on my local system, and since it's plugin based, I thought of searching for such plugins, and imagine my surprise that it actually exists!

It's built in, and it's called Remote System Explorer.

C++ / Python / C# speed

The beginning

Even though there are many language tests out there on the internet, I wanted to have a go at it myself, to find out the cases I wanted to know about and to have control over the test. Also, I wanted to do it because I thought it might be fun to write a little testing framework and reporting tools! (And it would make some nice weekend programming)

But even though this might be a bit whimsical, one real question I've had for some time is "how fast/slow is Python compared to C#" (Or C++ even) ? So I went ahead and tested the languages I come across most often: C++, Python & C#.

If you want to skip to the results, here they are:

http://jcash.github.io/languagetests/

And here is the code:

https://github.com/JCash/languagetests

Compacting Virtual Box Drives

Too many times I've forgotten the exact commands on how to compact the virtual drives. Especially for windows, where the tool used, used to have a different name of the argument passed to it. Compacting the drive can save you lots of disc space (last time my drive went from 12GB to 5GB), and for a smaller lap top drive, that makes a big difference.

Windows Guest:
Download SDelete from SysInternals and then run

Linux Guest:
Here, we create a file that fills the entire empty space, and then deleting it:
Host:
Finally, you let VirtualBox compact the drive

That's it really! I hope I'll remember it a little better this time.

Further info:
Use “sdelete -z” when Shrinking a Windows Guest’s Virtual Hard Drive
How to Compact a VirtualBox Ubuntu Guest’s VDI file