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FunkyPenguinEuroBSDCon DevSummit Day 3
MimeKit: Coming to a NuGet near you.
If, like me, you've been trapped in the invisible box of despair, bemoaning the woeful inadequacies of every .NET MIME library you've ever found on the internets, cry no more: MimeKit is here.
I've just released MimeKit v0.5 as a NuGet Package. There's still plenty of work left to do, mostly involving writing more API documentation, but I don't expect to change the API much between now and v1.0. For all the mobile MIME lovers out there, you'll be pleased to note that in addition to the .NET Framework 4.0 assembly, the NuGet package also includes assemblies built for Xamarin.Android and Xamarin.iOS. It's completely open source and licensed under the MIT/X11 license, so you can use it in any project you want - no restrictions. Once MimeKit goes v1.0, I plan on adding it to Xamarin's Component Store as well for even easier mobile development. If that doesn't turn that frown upside down, I don't know what will.
For those that don't already know, MimeKit is a really fast MIME parser that uses a real tokenizer instead of regular expressions and string.Split() to parse and decode headers. Among numerous other things, it can properly handle rfc2047 encoded-word tokens that contain quoted-printable and base64 payloads which have been improperly broken apart (i.e. a quoted-printable triplet or a base64 quartet is split between 2 or more encoded-word tokens) as well as handling cases where multibyte character sequences are split between words thanks to the state machine nature of MimeKit's rfc2047 text and phrase decoders (yes, there are 2 types of encoded-word tokens - something most other MIME parsers have failed to take notice of). With the use of MimeKit.ParserOptions, the user can specify his or her own fallback charset (in addition to UTF-8 and ISO-8859-1 that MimeKit has built in), allowing MimeKit to gracefully handle undeclared 8bit text in headers.
When constructing MIME messages, MimeKit provides the user with the ability to specify any character encoding available on the system for encoding each individual header (or, in the case of address headers: each individual email address). If none is specified, UTF-8 is used unless the characters will fit nicely into ISO-8859-1. MimeKit's rfc2047 and rfc2231 encoders do proper breaking of text (i.e it avoids breaking between surrogate pairs) before the actual encoding step, thus ensuring that each encoded-word token (or parameter value) is correctly self-contained.
S/MIME support is also available in the .NET Framework 4.0 assembly (not yet supported in the Android or iOS assemblies due to the System.Security assembly being unavailable on those platforms). MimeKit supports signing, encrypting, decrypting, and verifying S/MIME message parts. For signing, you can either use the preferred multipart/signed approach or the application/[x-]pkcs7-signature mime-type, whichever you prefer.
I'd love to support PGP/MIME as well, but this is a bit more complicated as I would likely need to depend on external native libraries and programs (such as GpgME and GnuPG) which means that MimeKit would likely have to become 32bit-only (currently, libgpgme is only available for 32bit Windows).
I hope you enjoy using MimeKit as much as I have enjoyed implementing it!
Note: For those using my GMime library, fear not! I have not forgotten about you! I plan to bring many of the API and parser improvements that I've made to MimeKit back to GMime in the near future.
For those using the C# bindings, I'd highly recommend that you consider switching to MimeKit instead. I've based MimeKit's API on my GMime API, so porting to MimeKit should be fairly straightforward.
EuroBSDCon DevSummit Day 2
EuroBSDCon DevSummit Day 1
DAV Torture
Currently we speak a lot about performance of the ownCloud WebDAV server. Speaking with a computer programmer about performance is like speaking with a doctor about pain. It needs to be qualified, the pain, and also the performance concerns.
To do a step into that direction, here is a little script collection for you to play with if you like: the DAV torture collection. We started it quite some time ago but never really introduced it. It is still very rough.
What it does
The first idea is that we need a reproducable set of files to test the server with. We don’t want to send around huge tarballs with files, so Danimo invented two perl scripts called torture_gen_layout.pl and torture_create_files.pl. With torture_gen_layout.pl one can create a file that contains the layout of the test file tree, a so called layout( or .lay)-file. The .lay-file describes the test file tree completely, with names, structure and size.
torture_gen_layout.pl takes the .lay-file and really creates the file tree on a machine. The cool thing about is that we can commit on a .lay-file as our standard test tree and just pass a file around with a couple of kbytes size that describes the tree.
Now that there is a standard file tree to test with, I wrote a little script called dav_torture.pl. It copies the whole tree described by a .lay file and created on the local file system to an ownCloud WebDAV server using PUT requests. Along with that, it produces performance relevant output.
Try it
Download the tarball and unpack it, or clone it from github.
After having installed a couple of perl deps (probably only modules Data::Random::WordList, HTTP::DAV, HTTP::Request::Common are not in perl’s core) you should be able to run the scripts from within the directory.
First, you need to create a config file. For that, copy t1.cfg.in to t1.cfg (don’t ask about the name) and edit it. For this example, we only need user, passwd and url to access ownCloud. Be careful with the syntax, it gets sourced into a perl script.
Now, create the local reference tree with a .lay-file which I put into the tarball: ./torture_create_files.pl small.lay tree This command will build the file tree described by small.lay into the directory called tree.
Now, you can already treat your server: Call ./dav_torture.pl small.lay tree This will perform PUT commands to the WebDAV server and output some useful information. It also appends to two files results.dat and puts.tsv. results.dat just logs the results of subseqent call. The tsv file is the data file for the html file index.html in the same directory. That opened in a browser gives a curve over the average transmission rate of all subsequent runs of dav_torture.pl (You have run dav_torture.pl a couple of times to make that visible). The dav_torture.pl script can now be hooked into our Jenkins CI and performed after every server checkin. The resulting curve must never raise :-)
To create your own .lay-file, open torture_gen_layout.pl and play with the variables on top of the script. Simply call the script and redirect into a file to create a .lay-file.
All this is pretty experimental, but I thought it will help us to get to a more objective discussion about performance. I wanted to open this up in a pretty early stage because I am hoping that this might be interesting for somebody of you: Treat your own server, create interesting .lay files or improve the script set (testing plain PUTs is rather boring) or the result html presentation.
What do you think?
SpriteKit on Xamarin.iOS: fun without compromise
With the release of iOS7, and same day support in Xamarin.iOS, I'm spending all my free time playing with the new APIs. I particularly love iBeacon and Background Fetch. Next on my list was SpriteKit.
SpriteKit is a 2D game engine, not unlike cocos2d at all. We'll see next that it's going from one platform to another is very simple.
I'm not a game developer, but I have some experience with cocos2d as I co-wrote (with Miguel) the cocos2d bindings for Xamarin.iOS. At that time, to test the binding, I ported a sample platform jumper game from obj-c cocos2d to c#. And I again ported the same game to SpriteKit. Here are my findings about the experience:
The Pros
- you can almost to a line by line port between cocos2d and SpriteKit, once you figure out the basics
- less boilerplate. Or even no boilerplate at all with SpriteKit. a SKView is a UIView, and is ready to serve as soon as you PresentScene() it. Compare that with the directors you have to put in place before writing a line of game logic in cocos2d. It's a win.
- less leaky abstractions. I haven't compared performances, but SpriteKit doesn't expose stuffs like BatchNodes, so it's one stuff you don't have to bother about.
- SKAction is a nice addition for objects you don't want to animate yourself in your Update() loop (they're executed just after Update(), and before physics simulation)
The Cons
- I found myself looking for BitmapFonts. It seems like a standard in game development, but missing from SpriteKit (or I haven't found it). I'm quite confident that's a stuff we'll see in an upcoming new version.
The Rest
- As the original game, this port doesn't leverage any Physics engine, so I have nothing to say about SKPhysics* stuffs. From the API, it looks very similar to what Chipmunk offer.
The Code
The code is on github, it's MIT/X11 so do whatever you want with it. The graphics are borrowed from the original game, read the LICENSE about their usage.
ownCloud Client Release 1.4.1
I am happy to announce that we today were able to release version 1.4.1 of the ownCloud Desktop Client on the three platforms Linux, MacOS and Windows.
You find suitable download links as usual at: http://owncloud.org/sync-clients/
Version 1.4.1 is a bugfix release for the 1.4.0 version released a few of weeks ago which brought a lot of new features. This one solves a couple of problems that were coming up during the last few weeks. For example, the problem that the client lost its configuration (at least) on the Win32 platform when the machine was shut down is fixed. Also a lot of redundant uploads wont happen any more. And there are even more fixes, as the detailed Changelog rules out.
We thank you for your ongoing support and the good work on bugs that came up. As usual we are looking forward to your feedback. Please work with us in the Github bugtracker if you experience issues.
Olé to you nonetheless
http://www.ted.com/playlists/11/the_creative_spark.html
"If your job is to dance, do your dance. If the divine, cockeyed genius assigned to your case decides to let some sort of wonderment be glimpsed, for just one moment, through your efforts, then "Olé!". And if not, do your dance anyhow. And "Olé!" to you nonetheless."
The talk is about how artists can get broken because of the anxiety of thinking they may not be able to do a great creation but I think that can actually be applied to any aspect of your life.
In ancient times, people used to believe there was a God that was ruling our lifes and what was happening was because of his plans. This was a way of managing uncertainty in their lifes, since there were a plan and rules designed for some higher entity, despite people was not able to understand them.
Then, people started to think that we are the center of the universe, ... and then we killed God when we tried to demonstrate every single thing through science and rules that are understandable by humans (well, not by all of them, but a set of humans). And we started believing we are in control and so we are responsibles of our own future (don't get me wrong, I think science has bring very very good things to humanity).
However, believing we can control, brings great responsability on our lifes, new rules (to avoid damages we can avoid because WE are in control), and at the end anxiety and stress. Then ... should we go back to believe in unnatural things?
Well, why not go back to believe we are not in control and that we do our best and then, because of "Gods", coincidences or other unnatural "things" that we don't know, don't understand and can't control, things will go in a way or in another, thus leaving us living with some uncertainty? Is this the next step?
Introducing Find Many Strings v2 - A chrome extension
Some of you might remember my chrome extension to search and highlight multiple strings simultaneously. I made an update to it recently and gave the ability to input multiple strings in one click. Here is an introductory video of the extension in action. Recommended to be watched in full screen.
The video along with the full subtitle support (so as to help a11y) was made Tharkuri. A big thanks for this strenuous job. If you are looking for someone to do [online] marketing / professional writing work in India, I highly recommend Tharkuri.
You can get the extension from the chrome store and the sources from the github repository. Please report any bugs / features to the github page and any feedback in the extension page or by mail.
Xamarin.iOS 7 : iBeacons - Part 1: Advertizing
iBeacons is a protocol on top of Bluetooth LE (Low Energy, also advertised as Bluetooth Smart, and part of the Bluetooth 4.0). It doesn't require any new hardware and is nothing really new by itself. What's new and exciting is its position in iOS: first-class citizen, integrated with CoreLocation, working in the background, ...
The recipe: advertising your position
1. Initialize a CLBeaconRegion
var beaconId = new NSUuid ("5a2bf809-992f-42c2-8590-6793ecbe2437"); //uuidgen on MacOS, nguid in VS
var beaconRegion = new CLBeaconRegion (beaconId, "yourOrg.yourBeacon");
2. Initialize a CBPeripheralManager
var peripheralManager = new CLPeripheralManager (new PeripheralManagerDelegate(beaconRegion), DispatchQueue.DefaultGlobalQueue, new NSDictionary ());
class PeripheralManagerDelegate : CBPeripheralManagerDelegate
{
CLBeaconRegion beaconRegion;
public CBPeripheralManager (CLBeaconRegion beaconRegion)
this.beaconRegion = beaconRegion;
}
public override void StateUpdated (CBPeripheralManager peripheralManager)
{
//State will be Unsupported on devices like iPhone4 and prior, PoweredOff if BT is down
if (peripheralManager.State != CBPeripheralManagerState.PoweredOn)
return;
var options = beaconRegion.GetPeripheralData (null);
peripheralManager.StartAdvertizing (options);
}
}
Notes and further reading
- As devices BT ids changes from time to time, your device will be sometimes advertised twice. That won't happen with real iBeacons.
- If you want to advertize in the Background, enable "Acts as Bluetooth LE accessory" in your info.plist
- Read Region Monitoring if you need more details.