Unintelligible

Quick and dirty script:

DECLARE @old sysname, @current sysname, @TABLE sysname, @COLUMN sysname,
    @this_old sysname
DECLARE uq_cursor CURSOR FOR 
    SELECT AllUQs.name AS old_name, object_name(AllUQs.parent_obj) AS table_name,
            col.name AS column_name
        FROM dbo.sysobjects AS AllUQs
        JOIN dbo.sysindexes AS ix ON (ix.id = AllUQs.parent_obj)
                               AND (ix.name = AllUQs.name)
        JOIN dbo.sysindexkeys AS [KEY] ON ([KEY].id = ix.id) AND ([KEY].indid = ix.indid)
        JOIN dbo.syscolumns AS col ON (col.id = ix.id) AND (col.colid = [KEY].colid)
        WHERE AllUQs.xtype = 'UQ'
        ORDER BY old_name
OPEN uq_cursor
    FETCH NEXT FROM uq_cursor INTO @old, @TABLE, @COLUMN
    SET @current = 'UQ_' + @TABLE
    SET @this_old = @old
    WHILE @@FETCH_STATUS = 0
    BEGIN
        IF (@this_old != @old)
        BEGIN
            print @this_old + ' - ' + @current
            -- EXEC sp_rename @this_old, @current, 'OBJECT'
            SET @current = 'UQ_' + @TABLE + '_' + @COLUMN
            SET @this_old = @old
        END
        ELSE
        BEGIN
            SET @current = @current + '__' + @COLUMN
        END
        FETCH NEXT FROM uq_cursor INTO @old, @TABLE, @COLUMN
    END
    print @this_old + ' - ' + @current
    -- EXEC sp_rename @this_old, @current, 'OBJECT'
CLOSE uq_cursor
DEALLOCATE uq_cursor

This will rename all unique constraints to UQ_TableName_Column1Name_Column2Name (for a unique constraint on two columns.)

Hope this helps someone save themselves 15mins of SQL…

I just wrote a quick MSBuild wrapper around the great Gendarme tool. It allows running Gendarme as part of an MSBuild task/project, and supports all the options that the command-line runner supports.

It also integrates with Visual Studio:

The binary can be downloaded here: http://github.com/unintelligible/GendarmeMsBuild/downloads

The source code is available here: http://github.com/unintelligible/GendarmeMsBuild

For some reason, I couldn’t find a list of the different Resharper code inspections and their severity anywhere on the web (not even in Jetbrains’ site); this is useful to go through the available inspections with team members to decide which we should enable across our team.

So, for convenience, I’m posting one here; this is for Resharper 4.5. Click to expand the table.

Apologies for the formatting; you can also download the CSV.

A while ago, I found an article about implementing a named lock class in C#, allowing for the following code:

private static NamedLock<string> namedLock = new NamedLock</string><string>();
public void DoSomethingConcurrent(string lockName)
{
    using (namedLock.Lock(lockName))
    {
       //Do something concurrent
    }
}
</string>

This is useful because it allows the same code block to be run concurrently, with locking occurring depending on the arguments being passed in. The author thought it might be useful to have some reader-writer type functionality added in too though; since I had a similar requirement, I wrote a named reader-writer lock, based partly on the NamedLock posted above but using a ReaderWriterLockSlim as the underlying lock rather than a simple Monitor.

I’ve posted the code to Github, including a unit test suite. The most interesting file is the class itself. Usage is almost identical to the NamedLock:

private static NamedReaderWriterLock<string> namedRWLock = new NamedReaderWriterLock</string><string>();
public void DoSomethingConcurrent(string lockName)
{
    using (namedRWLock.LockRead(lockName))
    {
       //Do something concurrent that only requires 
       //read access to the resource
    }
    using (namedRWLock.LockUpgradeableRead(lockName))
    {
       //Do something concurrent that only requires 
       //read access to the resource, but that may require
       //upgrading to a Write lock later in the code
    }
    using (namedRWLock.LockWrite(lockName))
    {
       //Do something concurrent that requires 
       //write access to the resource
    }
}
</string>

Performance-wise, the reader-writer functionality does seem to improve concurrent access over the named lock; here’s the output of the performance tests running on my machine:

NameLock_vs_NamedReaderWriterLockSlim_PerformanceTest_Balanced
 
Run 1 - finished NamedRWLock run in 3734.2794ms
Run 1 - finished NamedLock run in 5499.8592ms
Run 1 - finished Monitor run in 5468.61ms
Run 2 - finished NamedRWLock run in 3609.2826ms
Run 2 - finished NamedLock run in 5468.61ms
Run 2 - finished Monitor run in 5468.61ms
Run 3 - finished NamedRWLock run in 3609.2826ms
Run 3 - finished NamedLock run in 5468.61ms
Run 3 - finished Monitor run in 5515.4838ms
 
3 passed, 0 failed, 0 skipped, took 47.92 seconds.
 
NameLock_vs_NamedReaderWriterLockSlim_PerformanceTest_SkewedRead
 
Run 1 - finished NamedRWLock run in 6656.0796ms
Run 1 - finished NamedLock run in 8843.5236ms
Run 1 - finished Monitor run in 8812.2744ms
Run 2 - finished NamedRWLock run in 6562.332ms
Run 2 - finished NamedLock run in 8812.2744ms
Run 2 - finished Monitor run in 8812.2744ms
Run 3 - finished NamedRWLock run in 6562.332ms
Run 3 - finished NamedLock run in 8812.2744ms
Run 3 - finished Monitor run in 8812.2744ms
 
3 passed, 0 failed, 0 skipped, took 76.59 seconds.

These tests compare the performance of the NamedReaderWriterLock with the NamedLock, using a standard Monitor as a control value. The first set of tests balances reads and writes, whereas the second performs four times more reads than writes (and likely reflects real-life scenarios more closely.)

The NamedReaderWriterLock provided around 35% improvement over the NamedLock in the test where as many writes as reads are performed, and a 25% improvement in the test skewed towards reads. This is a reasonably figure, although in the greater scheme of things it’s likely to be a only a minor improvement compared to the cost of, say, making a DB call; still, it’s worth having.

The code is available under the BSD license.

Installing Selenium as a Windows service is reasonably straightforward - based on the instructions for Fitnesse, which unfortunately seem to have been deleted from the Fitnesse wiki, but which have been reproduced here.

There are two parts to doing this - the first, registering the service using srvany.exe (which wraps any executable as a service), and the second, adding the keys to the registry to tell srvany.exe how to launch Selenium-RC. srvany.exe is a part of the Windows Resource Kit, if you don’t have it already you will need to download it from Microsoft.

The following will register the Selenium service - on the command line (all in one line):

"C:\Program Files\Windows Resource Kits\Tools\instsrv.exe" SeleniumRC
"C:\Program Files\Windows Resource Kits\Tools\srvany.exe" -a [myuser] -p [mypass]

This is assuming the Windows Resource Kit has been installed to its default location, “C:\Program Files\Windows Resource Kits”. Also, note that the user supplied needs to have the Log On As Service permissions assigned.

Now, add the following keys to the registry - this text can simply be copied-and-pasted to a .reg file, then double-clicked to add the entries to the registry:

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SeleniumRC\Parameters]
"Application"="java.exe"
"AppDirectory"="C:\\Program Files\\selenium-server-1.0.1"
"AppParameters"="-Xrs -jar selenium-server.jar"

You should now be able to start the service - if you get an error about the service failing to start due to a logon issue, make sure that the user you are using to run the service has been granted Log On As A Service permission (editing the service logon credentials in the Services MMC snap-in and saving the changes will cause this to happen automatically.)

A few months ago, I posted an entry on how Rubyists sometimes get distracted by the power of the language, preferring lengthy debates on programming aesthetics to actually writing (efficient) code. I compared this to photography, in which aspiring photographers sometimes get lost in technical discussions rather than focussing on the work they produce. Then I came across this quote, which concisely expresses in 3 sentences what I hadn’t managed in an entire post:

Every medium suffers from its own particular handicap. Photography’s greatest handicap is the ease with which the medium as such can be learned. As a result, too many budding neophytes learn to speak the language too long before they have anything to say.

(Will Connell, 1949, via Brendan MacRae, via Tim Bray)

The point of my original post was that the same may apply to Ruby; the language’s power and accessibility makes everything seem so easy, that it becomes tempting to engage in discussions about the finer points of programming aesthetics rather than focussing what one has to say (i.e. the problems one chooses to solve.)

The ‘sc‘ utility can be used to create, delete or edit a Windows service. It can be used for any executables (as opposed to installutil, which can only be used for .Net services). Its help is available using sc /help (and is also available on MSDN); however, I found the output slightly confusing, so for my own reference here’s an example for creating a service for the Subversion server:

sc create svnserve binPath= "\"C:\Program Files\CollabNet Subversion Server\svnserve.exe\" 
  --service -r \"c:\svn_repository\" --listen-port \"3690\"" DisplayName= "Subversion Server"

This passes two parameters, the binPath and the DisplayName (the rest are the directives Subversion expects when running as a service). The trick here is the space between the ‘=’ sign after the parameter name and the parameter value; the service won’t be installed otherwise.

Like several other people, I was fascinated by Roger Alsing’s post shortly before Christmas describing his program to evolve an image look like Leonardo’s Mona Lisa, using only semi-transparent polygons. This uses genetic programming (or perhaps more accurately, simulated annealing, a Monte Carlo method) to evolve an image, comparing each evolved image to its parent and deciding whether it is closer to the target image; if it is closer to the target, the image is retained and then evolved further.

Since Roger released his source code, there have been several other implementations in different languages, such as Javascript and Clojure. I thought that converting the program to another language would be an excellent way to understand how it works; so, I converted it to Ruby (actually JRuby, as Swing is used for drawing the images and the user interface).

I’ve uploaded the code to GitHub; my implementation is pretty much a straight port of Roger Alsing’s original code though, and generally speaking it’s a little quick and dirty; I may eventually spend a little time tidying and/or optimising it, but as of yet it isn’t either elegant or fast.

This short clip shows the evolution of the selected candidates over 75000 generations (around four hours on my machine).

It’s been a year now since I switched to the Dvorak keyboard layout and learned to touch-type, so it seemed like a good time to assess progress so far.

I now consistently type between 60 and 70 WPM, depending on the day and the text I need to type. I’m reasonably happy with this, but when I originally switched, I was hoping that I would get up to 80-90WPM within a year. Also, I can’t really touch-type numbers, and I usually need to look at the keyboard to type some of the non alpha-numerical numbers that get used often when developing (e.g. ‘[', ']‘, ‘$’, ‘^’ etc.). Finally, typing still hasn’t really become as automatic as I’d hoped it would; to achieve high speeds, I still need to concentrate on typing, whereas I was hoping that I would have interned the typing to an extent that I didn’t really need to think about it anymore.

So, I think I’m going to start practicing again (in fact, I already started a little over Xmas). I’m kind of hoping to have resolved all of the above by June this year, so that I can finally stop thinking about typing

When running an application pool in IIS under a different user than the default, for an application that requires write access to the Event Log (for example, when trying to create a new event source in your application), it is necessary to grant that user sufficient access to the event log in the registry. Otherwise, you would receive the following error:

System.Security.SecurityException: Requested registry access is not allowed.

However, using Windows 2003 Server, I found that granting ‘read’ access to the event log wasn’t enough; the full set of permissions I ended up need to grant to the app pool user on the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog key in the registry is as follows:

I hope that this helps someone.