Humor

NHibernate – Get Thou Out Of My Database – 2nd Edition

Ayende Rahien — Mon, 08 Jun 2009 16:03:00 GMT

Following up on my previous post, the customer has complained about table names like [tbl_-1434067361], apparently they felt that this was misusing their naming policy. I told them that while I understood that, it did meet their naming policy. I got a new naming policy that stated that numbers are not allowed in column or table name, (and showing forethought) that table names must be composed of valid English words.

I, of course, decided that if this is what they wanted, they will get just that. And created this:

The words.txt file was taken from this URL: http://www.puzzlers.org/pub/wordlists/pocket.txt

The result is exactly per their specification:

create table [tbl_colonel] (
  [col_verbiage] INT IDENTITY NOT NULL,
   [col_unsparing] NVARCHAR(255) null,
   [col_indomitable] NVARCHAR(255) null,
   [col_bulldog] BIT null,
   [col_thank] DATETIME null,
   primary key ([col_verbiage])
)
create table [tbl_stump] (
  [col_upheaval] INT IDENTITY NOT NULL,
   [col_promissory] NVARCHAR(255) null,
   [col_predecessor] NVARCHAR(255) null,
   [col_chafer] NVARCHAR(255) null,
   [col_unyoke] INT null,
   [col_vise] NVARCHAR(255) null,
   PostId INT null,
   primary key ([col_upheaval])
)

create table [tbl_reprieve] (
  [col_wherewith] INT IDENTITY NOT NULL,
   [col_wolf] VARBINARY(8000) null,
   [col_legendary] NVARCHAR(255) null,
   [col_ago] NVARCHAR(255) null,
   [col_carabineer] DATETIME null,
   [col_referee] NVARCHAR(255) null,
   primary key ([col_wherewith])
)

The fun part about this approach is that you still get great level of security, while maintaining the naming convention. Even more than that, you get queries like:

SELECT col_verbiage, col_indomitable, col_bulldog, col_wolf, col_legendary, col_referee
FROM tbl_colonel JOIN tbl_repreieve ON tbl_repreieve.tbl_referee = tbl_colonel.col.unsparing
WHERE col_ago = 'Fun@house.at'

It is obvious that we are getting users & blogs with specific email, right?

This is actually much harder than just numeric values, because this is going to really mess with your mind.

Nitpicker corner: Yes, this is a humorous post, don’t take it seriously, and please don’t really do it to unsuspecting customers / DBAs. Unleash it on silly integration teams only.

Does this include a trip to Mars as well?

Ayende Rahien — Tue, 02 Jun 2009 10:45:15 GMT

I'll be the first to admit that I am not the best at Geography, but somehow I don't think that this is likely.

Random Developer Quotes

Ayende Rahien — Wed, 13 May 2009 10:20:00 GMT

Those are just things that I happened to hear or say in the last week:

Q: Did you read the book Beautiful Architecture?

A: No, I don’t read fantasy books.

And:

Q: Why are you doing the dishes?

A: I was a C++ programmer for a long time, I am used to cleaning up after myself.

Post #4000

Ayende Rahien — Tue, 12 May 2009 23:28:58 GMT

Dear ALT.NET Community,

You are likely familiar with that classic Warren Zevon song, Werewolves of London. I was reminded of this the last night being in London under a full moon and in the same hotel as one of the more famous Lycanthropic developers in the .NET community, Ayende Rahien, with whom you are also likely familiar as, well, you are reading his feed. Duh.

Shocked? Read on...

To call Ayende a werewolf is inacurate, of course. A lycanthrope, yes: Half-man, half-animal (i.e. manimal). But his primal half does not take the form of the lupine. Rather, Ayende is a were-Rhino. This should be obvious given the various logos and trade names he chooses. There you have it! His shape-shifting nature explains his Rhino fetish along with the genesis of the names of such projects RhinoMocks, RhinoCommons, Hibernating Rhinos, etc.

Yes we're all familiar with the conventional wisdom detailed in the classic essay of the same name by Fred Brooks, "No Silver Bullets." In this corner case of our industry there is a silver bullet, a couple (luckily, friends)!

There are a few things you can do to protect yourself from this marauding monster, Mr. Rahien. When in his manimilian state, if you ask him a question about NHibernate, you will stop the abomination in his tracks. If, being a proper member of the ALT.NET tribe, you cannot think of an NHibernate question (as you are undoubtedly an expert at this point) engage the brute in a discussion regarding the popular science fiction book series, "The Wheel of Time." That should do.

IMPORTANT: a curious, oft-overlooked but quite dangerous feature of the wererhino is that the beastly transformation can be triggered when the subject views a piece of code built on the Entity Framework. Be very, very careful when working with EF code around Ayende.

You have been warned.

Yours truly,

Dave Laribee

Why I released Windsor?

Ayende Rahien — Thu, 07 May 2009 21:56:23 GMT

Because getting kicked that many times will hurt:

1st April Post – The multi purpose method

Ayende Rahien — Wed, 01 Apr 2009 20:28:23 GMT

Since it appears to be customary, I decided that I need to make a few posts for April 1st. Here is the second of them.

public void RemoveReversalsMoveCompletedMessagesAndFinishSubQueueMove(Guid transactionId)
{
    Api.JetSetCurrentIndex(session, txs, "by_tx_id");
    Api.MakeKey(session, txs, transactionId.ToByteArray(), MakeKeyGrbit.NewKey);

    if (Api.TrySeek(session, txs, SeekGrbit.SeekEQ) == false)
        return;
    Api.MakeKey(session, txs, transactionId.ToByteArray(), MakeKeyGrbit.NewKey);
    Api.JetSetIndexRange(session, txs, SetIndexRangeGrbit.RangeInclusive | SetIndexRangeGrbit.RangeUpperLimit);
    
    do
    {
        var queue = Api.RetrieveColumnAsString(session, txs, txsColumns["queue"], Encoding.Unicode);
        var bookmarkData = Api.RetrieveColumn(session, txs, txsColumns["bookmark_data"]);
        var bookmarkSize = Api.RetrieveColumnAsInt32(session, txs, txsColumns["bookmark_size"]).Value;

        var actions = GetQueue(queue);

        var bookmark = new MessageBookmark
        {
            Bookmark = bookmarkData,
            QueueName = queue,
            Size = bookmarkSize
        };

        if (actions.GetMessageStatus(bookmark) == MessageStatus.Processing)
            actions.MoveToHistory(bookmark);
        else
            actions.SetMessageStatus(bookmark, MessageStatus.ReadyToDeliver);

        Api.JetDelete(session, txs);
    } while (Api.TryMoveNext(session, txs));
}

And yes, it is from real code, and it is going to production soon.

1st April Post – Sending Data

Ayende Rahien — Wed, 01 Apr 2009 20:25:58 GMT

Since it appears to be customary, I decided that I need to make a few posts for April 1st. Here is the first of them.

private IEnumerator<int> SendInternal(AsyncEnumerator ae)
{
    try
    {
        using (var client = new TcpClient())
        {
            try
            {
                client.BeginConnect(Destination.Host, Destination.Port,
                                    ae.End(),
                                    null);
            }
            catch (Exception exception)
            {
                logger.WarnFormat("Failed to connect to {0} because {1}", Destination, exception);
                Failure(exception);
                yield break;
            }

            yield return 1;

            try
            {
                client.EndConnect(ae.DequeueAsyncResult());
            }
            catch (Exception exception)
            {
                logger.WarnFormat("Failed to connect to {0} because {1}", Destination, exception);
                Failure(exception);
                yield break;
            }

            logger.DebugFormat("Successfully connected to {0}", Destination);

            using (var stream = client.GetStream())
            {
                var buffer = Messages.Serialize();

                var bufferLenInBytes = BitConverter.GetBytes(buffer.Length);

                logger.DebugFormat("Writing length of {0} bytes to {1}", buffer.Length, Destination);

                try
                {
                    stream.BeginWrite(bufferLenInBytes, 0, bufferLenInBytes.Length, ae.End(), null);
                }
                catch (Exception exception)
                {
                    logger.WarnFormat("Could not write to {0} because {1}", Destination,
                                      exception);
                    Failure(exception);
                    yield break;
                }
            
                yield return 1;

                try
                {
                    stream.EndWrite(ae.DequeueAsyncResult());
                }
                catch (Exception exception)
                {
                    logger.WarnFormat("Could not write to {0} because {1}", Destination,
                                      exception);
                    Failure(exception);
                    yield break;
                }

                logger.DebugFormat("Writing {0} bytes to {1}", buffer.Length, Destination);

                try
                {
                    stream.BeginWrite(buffer, 0, buffer.Length, ae.End(), null);
                }
                catch (Exception exception)
                {
                    logger.WarnFormat("Could not write to {0} because {1}", Destination,
                                    exception);
                    Failure(exception);
                    yield break;
                }
            
                yield return 1;

                try
                {
                    stream.EndWrite(ae.DequeueAsyncResult());
                }
                catch (Exception exception)
                {
                    logger.WarnFormat("Could not write to {0} because {1}", Destination,
                                      exception);
                    Failure(exception);
                    yield break;
                }

                logger.DebugFormat("Successfully wrote to {0}", Destination);

                var recieveBuffer = new byte[ProtocolConstants.RecievedBuffer.Length];
                var readConfirmationEnumerator = new AsyncEnumerator();

                try
                {
                    readConfirmationEnumerator.BeginExecute(
                        StreamUtil.ReadBytes(recieveBuffer, stream, readConfirmationEnumerator, "recieve confirmation"), ae.End());
                }
                catch (Exception exception)
                {
                    logger.WarnFormat("Could not read confirmation from {0} because {1}", Destination,
                                      exception);
                    Failure(exception);
                    yield break;
                }

                yield return 1;

                try
                {
                    readConfirmationEnumerator.EndExecute(ae.DequeueAsyncResult());
                }
                catch (Exception exception)
                {
                    logger.WarnFormat("Could not read confirmation from {0} because {1}", Destination,
                                      exception);
                    Failure(exception);
                    yield break;
                }

                var recieveRespone = Encoding.Unicode.GetString(recieveBuffer);
                if (recieveRespone == ProtocolConstants.QueueDoesNotExists)
                {
                    logger.WarnFormat(
                        "Response from reciever {0} is that queue does not exists",
                        Destination);
                    Failure(new QueueDoesNotExistsException());
                    yield break;
                }
                else if(recieveRespone!=ProtocolConstants.Recieved)
                {
                    logger.WarnFormat(
                        "Response from reciever {0} is not the expected one, unexpected response was: {1}",
                        Destination, recieveRespone);
                    Failure(null);
                    yield break;
                }

                try
                {
                    stream.BeginWrite(ProtocolConstants.AcknowledgedBuffer, 0,
                                      ProtocolConstants.AcknowledgedBuffer.Length, ae.End(), null);
                }
                catch (Exception exception)
                {
                    logger.WarnFormat("Failed to write acknowledgement to reciever {0} because {1}",
                                      Destination, exception);
                    Failure(exception);
                    yield break;
                }

                yield return 1;

                try
                {
                    stream.EndWrite(ae.DequeueAsyncResult());
                }
                catch (Exception exception)
                {
                    logger.WarnFormat("Failed to write acknowledgement to reciever {0} because {1}",
                                      Destination, exception);
                    Failure(exception);
                    yield break;
                }
                Success();

                buffer = new byte[ProtocolConstants.RevertBuffer.Length];
                var readRevertMessage = new AsyncEnumerator(ae.ToString());
                readRevertMessage.BeginExecute(
                    StreamUtil.ReadBytes(buffer, stream, readRevertMessage, "revert"), ae.End());
                yield return 1;
                try
                {
                    readRevertMessage.EndExecute(ae.DequeueAsyncResult());
                    var revert = Encoding.Unicode.GetString(buffer);
                    if (revert == ProtocolConstants.Revert)
                    {
                        Failure(null);
                    }
                }
                catch (Exception)
                {
                    // expected, there is nothing to do here, the
                    // reciever didn't report anything for us
                }

            }
        }
    }
    finally
    {
        var completed = SendCompleted;
        if (completed != null)
            completed();
    }
}

And yes, it is from real code, and it is going to production soon.

Raising the level of abstraction

Ayende Rahien — Wed, 11 Feb 2009 17:54:59 GMT

Right now I am working with a co-worker, and I realized that I am:

Using Mac OS
Running Windows in VMWare Fusion
To connect via SharedView to a remote machine
To connect via remote desktop to another machine
Which is also a virtual instance

And I wonder about the latency…

Laughing in code

Ayende Rahien — Tue, 10 Feb 2009 13:02:41 GMT

I am not sure that this will make any sort of sense world wide, but Israeli coders should have a chuckle or two over this:

There is no database

Ayende Rahien — Wed, 14 Jan 2009 22:38:46 GMT

I just noticed that for the last few months I have been consistently denying the existence of a database. I use the term persistent storage when asked, and when asked I usually say: “There is no database”.

It has gotten to the point that this is how I draw the DB on most whiteboard sessions: