That’s all very interesting to us geeks, but does anybody outside of geekdom care? Well they do now: Google’s home page displays a customized version of the company logo to celebrate the event. Mouse over the logo displays “Happy New Year & 25 years of TCP/IP”, and if you click it, Google does a search for January 1 tcp/ip.

Question: Is copy-and-pasting chunks of code into our app, a good example of code reuse? My boss thinks that it’s a good idea, as we are making extensive reuse of code that we already wrote earlier in the development cycle rather than writing new code from scratch. Code reuse is supposed to be a good thing, right? (I’m not sure why, but I feel uncomfortable about duplicating so much code).

Bad Copy and Paste

The questioner (or perhaps more so, his boss) has a basic misunderstanding. The boss is assuming that Code Reuse is a goal in itself.

He’s wrong. It isn’t.

A key fundamental goal in software development, since we all want to do things in a way that avoids unnecessary time and expense, is to reduce duplication of effort.

Code Reuse is simply one method of working towards that fundamental goal. By putting code into subroutines or functions or classes or libraries, you (a) only have to write the code once initially, and (b) only have to go to one place in the code to maintain that algorithm.

If you copy and paste code, adding near-duplicate chunks of code in scattered places throughout your application, what happens? You’ve reduced the initial effort - as you only have to write the initial code once - but you’ve vastly increased the maintenance effort. Now if you want to make a change to that algorithm, you need to make the same change in all 57 (or whatever number!) of places it occurs in your code, you also have to try to remember to update all those 57 places (which is a struggle in itself), and finally you have to deal with extra bugs that arise because you forgot to update some of those 57 different places.

Maintenance and bug-fixing is by far the largest section of work in most projects, and copy-and-paste tends to vastly increase the duplication of effort, the exact opposite of the fundamental goal, which is to reduce duplication of effort.

Good Copy and Paste

There are cases however when copying-and-pasting code, duplicating it, can be a good thing. The reason is that reducing duplication of effort isn’t always the most important fundamental goal. Sometimes a more important fundamental goal is to reduce coupling.

Used intelligently copy-and-paste can reduce coupling. If you are fighting a tough schedule, a bit of copy-and-paste between projects can eliminate a bottleneck where two or more groups of developers are all awaiting a single change in a shared module. If there were only one bottleneck of this type, then the bottleneck probably wouldn’t have too much impact on your schedule, but if there are dozens or hundreds of these bottlenecks, then copy-and-paste, even if it involves duplicating code, can be a reasonable solution. In fact in this case, unless you copy-and-paste, your schedule may no longer be under your group’s control and become entirely unpredictable. In essence, the argument in favor of copy-and-paste is the same argument about removing dependencies that Joel used in his article, In Defense of Not-Invented-Here Syndrome.

One More Case

If life was simple (or maybe if I was a better self-editor?), I’d conclude after looking at the bad case and the good case, and then ask the reader to evaluate each situation from this point of view.

But there’s a third case…

Another argument that is sometimes made in favor of copy-and-pasting near-duplicate of sections of code, is that it reduces coupling by reducing the ripple effect of changing a shared function.

Here’s the example, let’s say there’s function X. It’s placed in a shared library (maximum code reuse!), and called by various modules in several different applications. A programmer then comes along and changes X (fixes a bug, adds a feature, changes the function’s side-effects, etc.,) so it now does something slightly different - which doesn’t affect where he is calling from - but does cause an unintended effect on the other places where X is called from.

Duplicating the innards of X as inline code at each point in the calling code, rather than calling a common function, would have avoided this problem, right?

Technically, provided you only focus in on the narrow details of this one function, this is argument is correct. However in this case, I have to think the cure is worse than the disease. Taken to the extreme, this in fact would be an argument in favor of never using functions - it takes us back to the Bad Copy and Paste situation that we’ve already discussed.

As far as I’m concerned the real problem is NOT that there is a shared function X, but rather that, what X is supposed to do, was never sufficiently well-defined. If what X does had been properly specified, including a clean API (including no weird or undocumented side effects), and programmers were aware that changing X from its specified behavior would have knock-on consequences, then the problem wouldn’t have arisen in the first place.

None of this is Rocket Science

Like the subheading says, this isn’t rocket science. What is needed is thought: thought about the goals and priorities when writing code, and thought about how to achieve them.

One thing I’ll say for sure though, based on my anecdotal experience: 99 times out of 100, copying-and-pasting of chunks of code is done without any deep thought at all - and in those cases, it’s nearly always pathological.

I know how to use a PC, but in other aspects of my life, I increasingly find that life is too darn short to read the manual. Fortunately however, even quite complex devices with a ton of functions can now be used adequately without reading or learning. I’ve been able to use my PlayStation, TV, microwave, electric oven and new mobile phone without ever reading the manual, or learning how to use them. Admittedly, I don’t necessarily know how to use every last function - for example - my oven has a feature where you can set it to come on at a certain time of day, and go to a certain mode, and run for a certain time - and while I can’t think of a use of a for that function, if I did and I wanted to use, I think that I would probably have to follow the instruction manual to use this function. Likewise I have sometimes browsed the instructions for PlayStation games, mostly for hints of how to play better - but I know it’s unnecessary - my 6 year old nephew can operate my PlayStation and its games, better than I can, without ever having read any instructions - he does it by a combination of 6-year-old commonsense plus trial and error.

The thing is computers, at least as far as the user interface is concerned, simply don’t have anything like the ease-of-use of other consumer devices yet. Read the first post in the JoelOnSoftware thread. Things like short-cuts, directory structures and needing to know which application does what are abstraction-leaks, where you need to know stuff about the internal operation of the computer which isn’t strictly relevant to getting a particular task done - such as simply wanting to prepare a document and keep it safe. By contrast, when using a mobile phone - I don’t need to know anything about how it stores my address book, or how it connects to the phone system.

With computers, because those abstractions leaks are so gigantic, the tendency is to slap a bandaid over them by using some pretty graphics, explanatory text, icons and what not. But really, when you think about it, an ordinary user shouldn’t be required to know things like the difference between a short-cut and an actual file, simply to avoid losing their work. Maybe in a decade or two, we’ll figure out how to make more usable PCs?

When these types of discussions come up, I often think of an episode of Star Trek NG, called "Hollow Pursuits". In this episode, Lieutenant Reginald Barclay’s character has an alternate life on the holodeck where he lives in a fake Starship Enterprise and is cool, commanding and respected, rather than the nervous dork that he is on the "real" Enterprise. The story is basically that of him learning to abandon his fantasy life and concentrate on real- life. At the end of the episode, Barclay tells the computer to delete all his holodeck-programs, and then after a long pause, says "Except program nine" (or something like that).

First please note that in no point during the episode did Barclay need to know the difference between a short-cut to a saved file, and the actual saved file - and nor did he need to know whether he authored his holodeck programs using PowerDeck 2457 or HoloPerfect version 900. But that isn’t what surprised me… What surprised me? Well, it’s just at the end, I always half expect the computer to say “Too late sucker, program nine has already been deleted”. I guess that I have become too used to computers being unfriendly!

The first thing to understand is who Paul Graham is. He’s a venture capitalist. He invests in tech start-ups. Yes he has a tech/programming background, but today he’s basically about investing in small tech start-ups with the idea that one of them will grow huge and make him a big pile of money to add to the big pile of money that he’s already got. Nothing wrong with that - although you do have to realize that it colors his arguments throughout.

If you read Graham’s two articles, especially the Cliff Notes follow-up article, apparently he doesn’t mean “dead” in the sense of going out of business. Or in the sense not making huge profits. Or in the sense of not producing anything new. Or not making products that vast numbers of people use and pay for. What he really means, is dead as in the sense that the start-ups he’s involved with, won’t be competing with or scared of Microsoft. The specific words he used is "What I meant was not that Microsoft is suddenly going to stop making money, but that people at the leading edge of the software business no longer have to think about them" - "leading edge of the software business" of course being a euphemism for the sort of start-ups that Paul Graham is involved with.

I could remark that’s a darn funny definition of "dead" as far as anybody living outside of Paul Graham’s VC tech bubble are concerned. But I think more interesting question is why start-ups aren’t concerned about competing with Microsoft.

Think back to the 1990s for a moment. A common, and highly fashionable, tech business plan (I’m not talking about the Internet retailer boom of selling groceries or other stuff online) was to build something around the web/Internet that would somehow make some part of Microsoft irrelevant. This was typified by Marc Andreessen of Netscape remarking how the browser would reduce Windows to "a set of poorly debugged set of device drivers", and Larry Ellison of Oracle Corporation predicting that the Network Computer would pretty much displace all use of PCs.

But would anybody be excited about this type of plan today? Is it cool? Fashionable? Where the hype is?

Today’s cool is YouTube, MySpace and Google. The kids want to be the next Chad Hurley - and Bill Gates is just a dorky middle-aged guy that your dad might have admired.

And that’s my thesis: the real reason that Paul Graham thinks that Microsoft is "dead" is simply because the kind of start-ups that he is involved with, are no longer trying to compete with, nor displace, Microsoft. In other words, he’s saying that his start-ups aren’t going to try to take a chunk out of Microsoft’s $44.2 billion (and growing) annual revenue. Or to put in other words, competing with Microsoft as a business-plan, at least as far as Paul Graham is concerned, is what is really dead.

That’s a pity really, because even though he says eventually Microsoft may encounter problems (who would have thunk?), Paul Graham effectively concedes that Microsoft is going to make a lot more money in future. Some people are going to get rich competing with, and taking a chunk out of Microsoft’s revenues - although apparently not Graham’s start-ups because it’s unfashionable to even try.

5. Sungem GIF Animation

This site contains a set of beautifully animated GIFs in the style of Japanese anime. I don’t think that there is much point to them, but the are wonderful to look at, and they have a bewitching, almost slightly hypnotic quality.

4. Eating in Space Kills

A scene from the movie Stars Wars (I suppose that I’m supposed to say Stars Wars IV: A New Hope) "enhanced" with a few digital extras. Why didn’t George Lucas think of that?

3. Mario Communist Edition

This one’s been doing the rounds rather a lot recently, but there’s a wider (tongue-in-cheek) meme that perhaps the 80s video game Super Marios contained subtle communist propaganda.

For more on the meme check out:

• Super Mario Communist - a nice Flash animation explaining the theory
• Is Mario A Communist? - a whole web site dedicated to theory

2. Pointer Molestation

This is a small GIF animation, but you can’t take your eyes off it. Even when you know that it loops (and the loop is very short), some part of your brain will try to convince itself that it is going to change in a moment and that you should keep watching.

1. Blue Ball Machine

There is absolutely no doubt in my mind that this is the world’s greatest animated GIF. It’s accompanied by annoying, but strangely appropriate music. Be sure to maximize your browser to get the full effect.

By the way, here’s another variant on the same idea.

To put it another way, there are 250 billion (2.5 X 10¹¹) stars in the Milky Way, and 70 sextillion (7X10²²) stars in the visible universe. 70 sextillion is an unimaginably huge number. And the point is that even if intelligent life is exceedingly rare, some of the stars ought to contain extraterrestrial civilizations. But no extraterrestrial civilizations have been detected.

There are lots of theories that attempt to explain the Fermi Paradox, and many of these are used in science-fiction stories. But here’s a short-film, hosted at YouTube, about a very different one, based on a Terry Bisson short-story.

For some more serious (but still lots of fun) science-fiction stories about the Fermi Paradox - as well as many other interesting ideas - I recommend Stephen Baxter’s Manifold books.

Be sure to watch this YouTube video carefully and since it’s short, maybe a couple of times: there’s a few bits of weirdness that you might not notice first time round. You can play it, pause it and click the slider to look out for these oddities - it may also help to turn up the brightness on your display.

1. Obvious creature features: gray skin, no hair, no eyebrows
2. When the creature is first seen, look carefully at its upper arm (1:15:12): it definitely looks strange - maybe even decayed (?)
3. Look carefully at the nose (1:15:17) - it looks flattened - perhaps even rotted away (?)
4. And finally of course, the haunting eyes (1:15:17)

Cue X-Files music.

• Adobe’s new offering will be software-as-a-service
• It will have reduced functionality compared to the desktop version of Photoshop
• It will be free and supported by advertising

And some of the obvious big picture questions:

• Will customers like the software-a-service model?
• Will graphics professionals want to use the online version?

But as a programmer, while those types of questions are intriguing, they aren’t the real issue that is bugging me.

My question is this: How is it going to work?

Now if you were to ask the stereotypical non-programming IT manager (sort of the like the pointy-haired guy in the Dilbert Books), he would probably tell you that is just some tedious "implementation detail", that Adobe’s super-smart programmers are sure to solve. In other words, they wouldn’t think that it’s not the kind of thing that these big picture articles need to cover.

But here’s the thing: I’m not just asking this question out of idle curiosity. I’m also asking it because sometimes the answers to these "implementation details" have huge implications. They set the parameters of what is possible, and therefore can give you some very strong hint abouts what type of product will be emerging.

So let’s think about it for a moment. In the old days of the web, you had to press a submit button or click a link to send info back to server. Now, of course, we’ve moved forward, and most serious applications which run in a browser are generally Ajax (Asynchronous JavaScript and XML) based. In Ajax applications, there is usually a fair amount of intelligence running within the browser (for example to generate a sophisticated user interface), and data is sent back to the server (which of course includes its only logic too), as the name implies, asynchronously, i.e. without the user having to take some special action.

I would think it’s almost certain that the online version of Photoshop will be based on Ajax. It’s the current vogue technology for web applications. It’s probably the technology that will help produce the most interactive user interface, which is of course very important for a graphics program. And Adobe have already developed some experience with it.

So how might an Ajax-ed Photoshop work. I can see three main alternatives:

1. The master copy of the image is always stored on the server. The user’s browser simply contains the code for displaying the current image, and the user interface for manipulating it. Whenever the user chooses a graphic operation that changes the image, the server makes the changes to its master copy, and user’s browser’s is updated.
2. The master copy of the image is initially stored on the server. The user’s browser downloads the image. When the user chooses a graphic operation that changes the image, the changes are made within the browser copy, and at some point the server is updated with the new version of the image from the user’s browser.
3. The master copy of the image is initially stored on the server. The user’s browser downloads the image. When the user chooses a graphic operation that changes the image, the changes are made on the client and its screen updated, and the server is told to do the same operations to its master copy of the image.

These options are not in fact mutually exclusive. For example, one option could be used for some graphic operations, and another option for other graphics operations. However, the program would be simpler to develop, if one method, ideally the first one (which is the simplest in terms of coding) were used throughout.

So Adobe could just use method 1, problem solved, right?

Sorry, wrong. One of the really cool things about Photoshop, is that it includes a highly interactive user interface. For example, if you want to brighten or sharpen an image, you can fiddle with a slider and see your image start changing immediately. If Adobe simply relied on method 1, the system would probably be too slow even for people with super-fast internet connections: every little nudge of the slider would result in a request to the server, and a new image being sent back.

Unfortunately methods 2 or 3, apart from the additional complexity they add, also have some problematic issues. The biggest issue here is whether JavaScript would be up to the job required for it to do image processing calculations on large images. For example, adjusting an entire image’s appearance may require several calculations per pixel, and therefore a 1000X1000 pixel would require millions of calculations. Could JavaScript do this (say) once per second in response to the user moving a slider in the GUI? While Adobe undoubtedly has some very clever programmers, and of course PC hardware is getting better and better all the time, I’m skeptical about whether this type of problem can be solved in the short-term.

So my predictions (okay guesses) are:

1. The online version of Photoshop will be implemented as an Ajax application
2. The interactivity of the user interface will be significantly reduced as compared to the desktop version (this is in addition to functionality that Adobe chooses to omit for whatever reason)

If you’re a programmer, you’ve probably read this far, and even if you don’t agree with every step in my chain of logic, you’re probably thinking to yourself: "Why is he pointing out the obvious?".

My answer: What’s obvious to you and me, doesn’t appear to be obvious to much of the tech press. Additionally, these "obvious" facts, also give an indication of the likely answers to some of the big picture questions raised in the press.

3. Will graphics professionals want to use the online version? My prediction: No, because it will lose all sorts of interactivity (as well as probably whatever functionality Adobe omits) as compared to the desktop version.

Update:

I’ve got lots of comments here saying that Adobe will probably use Flash and Flex (Flex being a bunch of technologies that allow better Internet applications using Flash). Perhaps they will, although I still suspect there will be some Ajax involvement in the user interface.

People who know considerably more about the subject than I do, tell me that Flash can manipulate bitmaps rather better JavaScript. No doubt they are right. Is it good enough to quickly manipulate a large image taken with digital camera? I don’t know - it’s possible that it could be - or failing that, Adobe, which owns Flash, could improve it until it is.

But even if they use Flash and Flex, and even if Flash is able to manipulate large images quickly enough, it still leaves the question of how they are going to deal with sending bitmaps back and forth between server and client. Which leads us back to the methods 1, 2 and 3 which I talked about in the article. Of course with a more powerful browser application, methods 2 and 3 become more practical… potentially allowing a more interactive user interface… but will it be as interactive as the desktop Photoshop, given current Internet speeds and all the round-trips required?

Here’s the information that I have gathered from my research (principally by sitting in front of the TV!):

• According to most reports, the fuel affected appears to be lead-free petrol sold by supermarket chains principally in Southeast England. However, watching BBC News 24 today (March 1st) and yesterday (February 28th), they’ve also read out emails and texts from viewers reporting other problems too - for example - one person said they believed their diesel vehicle had been affected! The 4pm BBC News 24 report also said they have been reports from the North and Scotland including in Newcastle and Dundee.
• Some reports say the problems first started in mid-February - so if there is contaminated fuel, much of it will have already passed through the system.
• Some reports including by one of by the AA reported in the Guardian say the cause of the problem is unknown.
• Other reports even go so far as saying the supermarkets in question have tested the fuel and found nothing wrong. [Question: Are they testing the right fuel - presumably they took some from cars that broke down? Are they testing for the right things].
• BBC News 24 began reporting this afternoon (March 1st) that an AA source is saying the cause may be excess silicon in the fuel. The explanation is that in modern cars there is an oxygen sensor in the exhaust, and sensor provides the information used by the Engine Control Unit (ECU) to control the fuel mix. The silicon is supposed to scum up the sensor.

So is it a real problem? Or hysteria?

With all this news, there are undoubtedly some cases of people blaming any other random problem they might have on their car, on "contaminated fuel". However, it definitely appears likely that there is a real problem in that there has been a huge run on the affected parts in garages.

One thought that occurs to me is that perhaps the problem was actually a few weeks ago - it took a while to mess-up the car - and only now, when cars have started failing - are drivers blaming the problem on their last fill-up (which may not be the one that caused the problem).

Here’s some of the better news links on the fuel contamination story:-

• BBC News - Inquiry into "contaminated" fuel
• BBC News - How can fuel become contaminated?
• Bucks Free Press - Tainted fuel angers motorists.
• Guardian - Source of fuel contamination still unknown
• Mirror - Cars crocked by dodgy fuel
• What Car? - Fuel Contamination Riddle Continues?

If you think you might be affected, the advice that I’m reading online is:-

• Retain evidence: Receipts for petrol purchases, a diary of your driving, if possible (get help from a garage) a small sample of petrol in an approved petrol container, as well as receipts etc., for any repairs or insurance claims.
• Stop driving immediately if your car is having problem: Keeping driving can make the damage worse.