Of course I have to post something about Google Reader, too

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The demise of Google reader viewed from a slightly different perspective. I find the analysis from someone who isn’t a proto-geek but rather an investment professional interesting, mainly because there are insights that some like me - who doesn’t spend the whole day looking at companies and trying to figure out what they are doing as opposed to what they say they are doing - would and this case, have missed.

If you’re using boost::variant, you need to have a look at Boost 1.53

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I was profiling some code a while ago that makes extensive use of boost::variant and one of the lessons from the profiler run was that boost variants appear to be fairly expensive to construct and copy. As of 1.53, variants support rvalue constructors and rvalue assignment operators. My initial measurements suggest that when used with types that are “move enabled”, there is a benefit in upgrading to this version of boost variant, both in performance and memory consumption.

Improving the Emacs integration in Windows

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I was trying to make Windows a little more Emacs-friendly (or was it the other way around?). First step was to enable the emacs server in my .emacs so I could make use of Emacs for quick and dirty editing tasks that require an editor better than Notepad but where the average Emacs startup time was just a little too long to make Emacs a viable alternative. A typical example would be to use Emacs as the editor for commit messages in Mercurial.

The stuff you find when you’re moving home

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Happy New Year to all readers. I’ve been blogging even less recently as we’ve just moved house but unpacking all the boxes meant that I came across one of my favourite magazines: German readers of this blog (if are there any) might recognise the magazine - it’s the first issue of “c’t”, a magazine that is still going on strong almost thirty years later. The issue above is dated November/December 1983 and has moved house (and continents) with me a fair number of times.

Windows 8 Pro on an early 2009 iMac 21.5 (Core 2 Duo)

Pete Barber from C#, C++, Windows & other ramblings

A couple of weeks back I thought I'd have a go writing a Windows Store App.  To do this requires Windows 8.  At the time I was running Windows 7 Home Premium on an early 2009 iMac 21.5 (Core 2 Duo).  This had been installed using Boot Camp including install Boot Camp assistant and the drivers supplied by Apple.

To upgrade to Windows 8 I wanted to avoid a re-installation of all my apps. and data etc so I went with an in place upgrade.  This all seemed to work properly and soon I was running Windows 8 and could access the Windows Store App templates from Visual Studio.  However, soon after Windows 8 kept crashing, well freezing.  It got to the point that after every reboot I'd be lucky to get 5 minutes of up time between each freeze.

Given that Apple haven't provided Windows 8 drivers yet this wasn't exactly a surprise.  I decided to try and work around this by rebooting to OS X and using VMWare Fusion to access the Boot Camp partition.  Whilst rebooting in OS X I managed to corrupt the Windows installation.  I use a non-Apple wireless keyboard (as I need the insert, delete, home & end plus the easily accessible cursor keys for VS development) so holding down Alt to select the OS to boot into didn't work.  When I realized it was going back into Windows I just turned the machine off.  After a couple of times the Windows installation was toast!  To get back to the point of trying Fusion I had to do a fresh Windows install.  In this case installing a minimal Windows 7 installation: just enough to allow the download of Windows 8.  I then installed Windows 8 using the preserve nothing option.

Having now gone through the steps I wanted to avoid I decided to give the new installation a go via direct boot, i.e. no Fusion.  That was two weeks ago.  Since then I've re-installed all the apps. and my personal data and (fingers crossed) haven't had a single crash.  As the freezes were usually happening during some graphical operation e.g. a status bar updating I assumed the fault probably lay with the video drivers.  I didn't install Boot Camp assistant and in particular the Windows 7 drivers from OS X disc.  Well, I did install one.  After a while I noticed I wasn't getting any sound even though all the audio drivers and hardware claimed they were happy.  Eventually I installed by the Cirrus Logic driver which made the speakers work. I haven't gone anywhere near the NVIDIA drivers.

So, the whole point of this post is for those who run Windows via Boot Camp on early iMacs and want to run Windows 8 then perhaps a fresh install (or maybe uninstall the Boot Camp supplied drivers prior to upgrade) is probably the way to go.

How to make a self-signed SSL certificate work with Windows RT’s Mail App on a Microsoft Surface RT

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Long title, I know… I was trying to get Windows RT’s Mail App to access the email on my own server. The server uses IMAPS with s self-signed certificate as I only want SSL for it encryption and don’t really need it for authentication purposes as well. As long as it is the correct self-signed certificate I’m happy. The Mail app however rejects certificates that weren’t signed by a trusted authority and doesn’t offer an obvious exception mechanism (like Thunderbird or Apple Mail) that circumvents the need for a trusted certificate.

I don’t want to see another ‘using namespace xxx;’ in a header file ever again

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There, I’ve said it. No tiptoeing around. As a senior developer/team lead, I get involved in hiring new team members and in certain cases also help out other teams with interviewing people. As part of the interview process, candidates are usually asked to write code, so I review a lot of code submissions. One trend I noticed with recent C++ code submissions is that the first like I encounter in any header file is

That’s another warranty voided, then

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Last night I did something I was adamant I wasn’t going to do, namely rooting my Android phone and installing CyanogenMod on it. Normally I don’t like messing with (smart)phones - they’re tools in the pipe wrench sense to me, they should hopefully not require much in the way of care & feeding apart from charging and the odd app or OS update. Of course, the odd OS update is can already be a problem as no official updates have been available for this phone (a Motorola Droid) for a while and between the provider-installed bloatware that couldn’t be uninstalled and the usual cruft that seems to accumulate on computers over time, the phone was really sluggish, often unresponsive and pretty much permanently complained about running out of memory.

A(nother) tool post

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I generally don’t post that much about the tools I use as they’re pretty standard fare and most of the time, your success as a programmer depends more on your skills than on your tools. Mastery of your tools will make you a better software engineer, but if you put the tools first, you end up with the cart before the horse. I guess people have noticed that I use Emacs a lot :).

Specifying the directory to create SQL CE databases when using Entity Framework

Pete Barber from C#, C++, Windows & other ramblings

In the last few posts I've been describing how to create instances of SQLCE in order to perform automated Integration Testing using NUnit and accessing the dB using Entity Framework.  I covered creating the dB using both Entity Framework and the SQL CE classes.  In particular I wanted control over the directory the dB was created in but I didn't want to tie to a specific location rather let it use the current working directory.

Using the Entity Framework's DbContext constructor that takes the name of a connection string or database name it's suddenly very easy to end up NOT creating the dB you expected where you expected it to be.  This post shows how to avoid these.  Generally speaking the use of the DbContext constructor that takes a Connection String should be avoided unless the name of a connection string from the .config file is being specified.

Example 1 - Using the SqlCeEngine class
1:  const string DB_NAME = "test1.sdf";  
2: const string DB_PATH = @".\" + DB_NAME; // Use ".\" for CWD or a specific path
3: const string CONNECTION_STRING = "data source=" + DB_PATH;
4:
5: using (var eng = new SqlCeEngine(CONNECTION_STRING))
6: {
7: eng.CreateDatabase();
8: }
9:
10: using (var conn = new SqlCeConnection(CONNECTION_STRING))
11: {
12: conn.Open(); // do stuff with db...
13: }
14:

The important thing to note is that the constructor for SqlCeEngine that takes an argument requires a Connection String, i.e. a string containing the "data source=...".  Just specifying the dB path is not sufficient.  To specify a specific directory  include the absolute or relative path.  To specify the current working directory, e.g. bin\debug then just use ".\".

Example 2 - Using DbContext (doesn't work)
1:  using (var ctx = new DbContext("test2.sdf"))  
2: {
3: ctx.Database.Create();
4: }

This code appears to work but doesn't create an instance of an SQL CE dB as desired.  Instead it creates a localDB instance in the user's home directory.  In my case: C:\Users\Pete\._test.sdf.mdf (& corresponding log file).  This is not really surprising as Entity Framework had no way of knowing that a SQL CE dB should be created.

Example 3 - Using DbContext (does work)
1:  Database.DefaultConnectionFactory =  
2: new SqlCeConnectionFactory(
3: "System.Data.SqlServerCe.4.0",
4: @".\", "");
5:
6: using (var ctx = new DbContext("test2.sdf"))
7: {
8: ctx.Database.Create();
9: // do stuff with ctx...
10: }

The difference between the last and this example is changing the default type of dB that EF should create.  As shown this is done by installing a different factory.

The 3rd parameter to SqlCeConnectionFactory is the directory that the dB should be created in.  Just like the first example specifying ".\" means the current working directory and specifying an absolute path to a directory will lead to them being created there.

NOTE: As per the post Integration Testing with NUnit and Entity Framework be aware that creating a dB using the Entity Framework results in the additional table '_MigrationHistory' being created which EF uses to keep the model and dB synchronized.

NOTE1: Whereas SqlCeEngine is a SQL CE class from the System.Data.SqlServerCe assembly, SqlCeConnectionFactory appears to be part of the System.Data.Entity assembly which is part of the Entity Framework.


In the above example the string passed to DbContext can be a name (of a connection string from the .config file) or a connection string.  In this case passing the name of the db, i.e. test2.sdf is equivalent to passing "data source=test2.sdf", well more or less.  If the '.sdf' suffix is omitted with "data source" then the resultant dB is called test2 but if just test2 is passed then the resulting dB will be called test2.sdf.

Example 4 - Using DbContext and the .config file
1:  using (var ctx = new DbContext("test5"))  
2: {
3: ctx.Database.Create();
4: }

App or Web .config
1:  <connectionStrings>  
2: <add name="test5"
3: providerName="System.Data.SqlServerCe.4.0"
4: connectionString="Data Source=test5.sdf"/>
5: </connectionStrings>

This time no factory is specified but the argument to DbContext is the name of a Connection String in the .config file.  As can be seen this contains similar information to that in the factory method enabling EF to create a dB of the correct type.

To use these the instances of these databases rather than calling the create method on the context just use the context directly or more likely in the case of EF a derived context which brings us to one last example.

Example 5 - Using a derived context and .config file
1:  public class TestCtx : DbContext  
2: {
3: }
4: using (var ctx = new TestCtx())
5: {
6: ctx.Database.Create();
7: }

App or Web .config
1:  <connectionStrings>  
2: <add name="TestCtx"
3: providerName="System.Data.SqlServerCe.4.0"
4: connectionString="Data Source=test6.sdf"/>
5: </connectionStrings>

If a derived context is created which will almost certainly be the case then if an instance of this is created and a dB created then EF will look for a Connection String in the .config file that has the same name as the context and take the information from there.