When I wrote about defending the code, I described how we don’t want to meet a date at the expense of our ability to meet future dates.  This applies to future projects as well.  If we meet the production date for the first project my producing a shaky pile of code, what is going to happen to the next project using that code base.  Some things can be scheduled for refactoring between projects.  This approach also requires trust on both sides for it to actually get done.  It also only works with selected and specific types of refactorings.

I think this is similar to Robert C Martin’s discussion on the “total cost of owning a mess”.  (Also from “Clean Code”.)  I like this expression because I think it accurately reflects what happens.  Changes get harder and harder to make as does the code mess.  They also become more and more risky.  Messy code is more likely to  introduce bugs when touched.  And bugs make the total cost of ownership skyrocket.  Which leads to an unfortunate feedback loop where things spiral out of control.  So it’s our job as professionals to make sure we do not introduce a mess and encourage our teammates to do the same.

On the other hand, we often have a mess as the status quo.  It might have been inherited from the prior author of the code.  Or it might have just snuck up on us.  When this happens, we can still try to make things better.  Even if it’s a tiny bit at a time.  Or by not making things worse.  It’s so easy to say “well it’s already a mess, so I’ll just add this hack here.”  That’s how it got to be a mess in the first place!

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Starting in a few hours, we will be hosting Uncle Bob (Robert C Martin) at JavaRanch in the Agile and Other Processes forum.  Come on in, ask him a question or join the discussion.  You might even win a free copy of the book Clean Code: A Handbook of Agile Software Craftsmanship.

As I read “Clean Code” by Robert C Martin, I was particular drawn to the passage about why unrealistic commitments should not be an excuse for writing bad code.  He points out that while it is a manager’s job to “defend the schedule and requirements”, it is a developer’s “job to defend the code with equal passion.”

What management says vs what management wants

One way this becomes a problem is when a developer hears management say “I want it by Tuesday.”  They may want it by Tuesday, but does that mean they are getting it by Tuesday.  The manager also wants it to work correctly and meet all the requirements. A manager isn’t going to be happy if we claim it is done on Tuesday and then a whole pile of rework needs to be done afterwards.  This really means the task wasn’t done by Tuesday and we just claimed it was.

“Done”

The manager also doesn’t want this one date to be met at the cost of meeting other dates. One way this comes up is by saying the task is done while silently thinking that parts of it will be done “later.”  Regardless of whether “later” ever comes about, the task isn’t REALLY done.  When I disagree with someone on whether a task is done, I’ll ask if they need anymore time to work on things related to it.  This may bring up parts of the task that aren’t really done.  Sometimes it brings up additional tasks that were discovered during this task.  Either way, it is often a productive answer.

Trust

When unrealistic estimates come up, there are often two responses.  One is to silently accept it knowing the date will not be met (or will be met at the cost of other things) because it is “what the manager wants.”  The other is to discuss why the estimate will not be met with management.  Of course, the later requires much more energy at first.  However, it pays off in getting everyone to have a realistic understanding of the project.

Schedule gambling

These other desires tend to be implicit, so we only hear the deadline. That doesn’t mean that the manager wants it done by Tuesday at the expense of all else.  I’m fond of saying that management would rather meet the production date than a development date.  So if we are meeting the development date at the expense of something that affects the production date, management will really be less happy.  This may be sloppiness that makes other tasks take longer or leaving parts of the task incomplete.

What all of these things have in common is that it is our responsibility as developers to keep management up to date and provide them with accurate visibility into what is going on within the project.

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This coming week we will be hosting Uncle Bob (Robert C Martin) at JavaRanch in the Agile and Other Processes forum.  Come on in, ask him a question or join the discussion.  You might even win a free copy of the book Clean Code: A Handbook of Agile Software Craftsmanship.

Donald Knuth is often quoted as saying “premature optimization is the root of all evil.”

Often in the JavaRanch forums, we see questions like:
which is faster stringBuilder.append(‘a’) or “a” + “b”
(The answer is these two expressions are supposed to generate to the same byte code if used on the same line.)

My first thought when I see this is who cares. I’d be very surprised if the bottleneck in an application was being caused by this line. I’d be even more surprised if the poster had done the analysis to prove this line is the performance bottleneck before posting.

What got me thinking about this is that I think I just wrote some premature optimization on a pet project.

/* Only do search and replace if one or more images in value. This is likely premature optimization but it's faster to add the if statement than find out. */
private String convert(String value) {
  String result = value;
  if (result .contains("<img src=")) {
    for (String imageName : setOfTwentyElements()) {
      // do a regular expression search and replace
      result = result.replaceAll(imageTag,  strippedOutImage);
    }
  }
  return result;
}

The fact that I commented it means I’m aware of doing it. Which is a step ahead of what usually happens where we write the optimization assuming it will be important and later (if ever) finding out otherwise.

In this case, I expect to run the method over a million times and the value not containing an image over half the time. After that the containing code will not live on. I also know the containing code contains a database update which means the code is not the bottleneck. To me, the extra if statement seems like a low cost to avoid doing some work at all. It also feels like a code smell for premature optimization. If this were a real application and not a pet project, I would invest some time in finding out how long the code actually takes to run for my data patterns/length.

Here I’m more interested in whether it is an example of premature optimization. I think I might have to leave it a philosophical question. Comments one way or the other are certainly welcome.  My leaning is that it is still premature optimization and this post is a rationalization.