But despite these wins, and numerous loyal fans, Wave has not seen the user adoption we would have liked. We don’t plan to continue developing Wave as a standalone product, but we will maintain the site at least through the end of the year and extend the technology for use in other Google projects.

That’s a great example of why “do one thing well” is better than “do it all”. Not only because, as Gall’s law implies, it’s easier to get a simple system straight, but also because once you get a complex system straight, you still have to make people get their mind around it. Wave made chat and e-mail play well together, with a great replay feature, bots and translation. Twitter gives short text updates. Adoption declared the winner, but we already knew it.

Here it is.

update: now i am linking to the extended version which i gave at phpday 2010

Why is that? Why when confronted by the possibility of rewriting their untestable bloatware, customer’s reply is almost always invariably “No, we don’t need it. We’ll just have to fix known bugs and add a couple of features, because right as it is, the software works ok…”?. What does “works ok” really mean? In my experience, it translates roughly to “The software does not physically blows up our office, it does some of the things we need to do, and over the years our employees have developed a thick skin against all the nuisances and a baggage of manual tricks, passed on by mouth, to get the rest of the work done anyway. Oh, and we already paid a lot for it”.

Recently, i got a taste of this mindset myself, when i booked online 2 tickets to Avatar at the local cineplex

“Hello this is my reservation code”

“Sorry Mr, those seats are reserved”

“Sure, by me”

“No, actually by others”

“What? see, i made this online reservation…”

“I see, but we take reservations both online and by phone, sometimes they overlap and phone is given priority”

“Overlap?! No trust me, i am a programmer, overlapping reservations are not supposed to happen, because your system has to take care”

“Oh, but evidently it doesn’t”

“WTF?!?!”

“Please, don’t get mad, i am gonna give you other seats. Today is not even bad. You should see how many angry people we must manage during christmas holidays when all movies are sold out!”.

Now, given that reservation means “An arrangement by which accommodations are secured in advance”, how would you rate a reservation system that does not guarantee secure accommodations? Like a fish unable to breathe underwater, yet they live with it, and this takes me to the point.

First, humans are best when it comes to adaptation. That means we naturally adapt to pain so that we don’t feel so bad, and adapt to pleasure so that we don’t feel so good. Perception of any external stimulus in the end comes to balance. Barry Schwartz in the Paradox of Choice says:

respondents were asked to rate their happiness on a 5-point scale. Some of them had won between $50,000 and $1 million in state lotteries within the last year. Others had become paraplegic or quadriplegic as a result of accidents. Not surprisingly, the lottery winners were happier than those who had become paralyzed. What is surprising, though, is that the lottery winners were no happier than people in general. And what is even more surprising is that the accident victims, while somewhat less happy than people in general, still judged themselves to be happy.

Second, humans are also very bad at admitting sunk costs. The idea of having spent money on something not worth is the ultimate inconvenient truth. Again Barry

Aversion to losses also leads people to be sensitive to what are called “sunk costs.” Imagine having a $50 ticket to a basketball game being played an hour’s drive away. Just before the game there’s a big snowstorm—do you still want to go? Economists would tell us that the way to assess a situation like this is to think about the future, not the past. The $50 is already spent; it’s “sunk” and can’t be recovered. What matters is whether you’ll feel better safe and warm at home, watching the game on TV, or slogging through the snow on treacherous roads to see the game in person. That’s all that should matter. But it isn’t all that matters. To stay home is to incur a loss of $50, and people hate losses, so they drag themselves out to the game.

Third, as brilliantly pointed out by Ryan Brush’s “Code is Design” in 97 Things Every Programmer Should Know and by Gabriele’s “Waterfall Pitfall #1″ (italian), uninformed most people understand software construction in terms of the better known building construction. Now, since programs are built out of bytes (not bricks), which are practically nothing, using mind (not excavators), which has no physical constraints, actual construction must be very cheap. This gives them the false hope of having an easy exit strategy at their disposal: fixing the software when an emergency comes up. Would they wait for a defective bridge to show the first cracks before attempting to fix it? Their unconstrained minds seem to be unable to realize that story construction aka book writing, built out of words, might represent a more fitting comparison and that The Divine Comedy took Dante, a renowned genius, more than ten years to finish.

Last but not least, mainstream has made a really good job at covering mistakes of incompetent programmers. From the almost sandboxed life cycle of a php script, to the rigid syntax of java and its self-correcting IDEs, to the plethora of useless certifications, great efforts have been devoted to make any primate with opposable thumbs able to program with very limited competence. Many and cheap, that’s how economy of scale is supposed to fail work, and that’s how we got this horde of unprofessional programmers sacking the best projects.

All of these points help to explain proliferation of crappy software. Maybe, they get it from some body rental which pays more for advertising than for the army of juniors that actually does the job. At the beginning it hurts, but they spent good money and cannot afford to accept failure, so lies are told and more time and money are invested to improve the situation. Then workarounds, albeit inefficient, come and direct suffering somehow decreases. Eventually, the pile of workarounds becomes part of company culture, and all is back to balance: the software starts working ok.

Unfortunately, this means that the quest for better software workflows can hardly come out of necessity, it must come out of vision, and vision takes inspiration fed to working brains then time for the masses to catch up. With Universe hopefully taking care of latter two, i like to think we, professional programmers, are those in charge of the former.

Until, from the midst of this darkness, a sudden light broke in upon me, a light so brilliant and wonderous, and yet so simple. Deep practice, eradicate errors and deep practice again. I alone succeeded in discovering the secret of bestowing skill. Nay, even more, I myself became capable of bestowing mastery upon apprentice matter.

It could work.

At the end of august 2009, while i was reading about the importance for a programmer to touch type, i found out many programmers could type at 80 wpm and above. I tried myself and consistently scored 60 wpm or below. I have been spending many hours a day at the keyboard since at least 1996. How could it be i am not as fast? I already knew about the importance of practice, but i did practice for years, didn’t I? Well, uhm, no.

Think of the career of a professional football (soccer) player. How does he get there, does he play all the time for years? Actually, he spends most of the week training: stretching, pushups, sprints, weights, long runs, ball work, etc… Only a small percentage of time is indeed to play short games and the main game on sunday. That’s because play alone can only push your performance to the upper end of the range set by current skill. It’s not going to push you to the next level, to the next order of magnitude, and it doesn’t keep you from developing bad habits. And that’s where i got, very fast at typing in my very flawed 7-fingers posture. Not able to improve any further, not even in more than 10 years.

I really wanted to get better, so the questions were How? and How long will it take? I didn’t know the answer to the latter but the former was by then clear in my mind. Find a keyboard dojo, do keyboard katas and take the needed time. After trying a lot of viable solutions i found my dojo at www.typingweb.com. To add some salt to the challenge i switched keyboard layout from italian to U.S., which is quite better for programming, and i started practicing daily with their courses, routinely taking tests to record my progress. Two pomodoros a day for the first two months, then one, then again two when i was reaching the end. Always striving to get 97% or above accuracy at the higher possible speed for every single lesson.

Now, five months and about 120 pomodoros of deep practice later, i am writing this to shout to the world that IT COULD WORK. Next i’ll be moving to vim katas, while still having some fun at www.typeracer.com, because you never really stop to practice right?!

Yours sincerely,
ten fingers typist
american layout
80 wpm average
up to 100 wpm under a good moon
Federico.

]]> http://federico.galassi.net/2010/01/27/how-i-did-it-touch-typist-in-five-months/feed/ 0 http://federico.galassi.net/2009/12/31/web-authentication-as-it-should-have-been/ http://federico.galassi.net/2009/12/31/web-authentication-as-it-should-have-been/#comments Thu, 31 Dec 2009 18:19:51 +0000 federico http://federico.galassi.net/?p=214

Having recently read RESTful Web Services, i wanted to write about the most interesting of my REST-induced epiphanies:

Form based authentication with its login/session/logout workflow, which is currently dominant on the web, is hopelessly broken.

To understand why, one has to grasp how the greatest living RESTful implementation, the web and its backbone protocol HTTP, was meant to work. In a nutshell, there’s a server that keeps the state of the web application, split into meaningful resources. Each resource has its own name (URI) and a set of available representations of itself. That’s all the server knows. Then there’s a client that acts as a finite state machine visiting resources, getting representations and then moving to other resources through links and forms. The state of the conversation, the session, where a client has been and where it is now, is something that belongs to the client. Server drives the client by feeding him a graph made of states and links to other states, but it’s the client who is in charge of following a path. That’s statelessness, the simplifying property that made the web triumph as a darwinian winner.

In this view, authentication should have been largely a client-side business.
The client visits resources anonymously. If it wants to be authenticated, it just starts sending authentication data with each further request. If it wants to be anonymous again, it just stops. It could as well send a mix of authenticated and anonymous requests.
The server doesn’t care of what happens between requests. If a single request carries authentication data, it checks the data and possibly replies as if the client were authenticated. If a request has no authentication data, a generic response is returned. There’s no server-side login through a form, there’s no server-side logout, and above all, there’s no temporal ordering between those two and hence no server tracked session. All of a sudden, the beauty of this comes with great force. By delegating authentication to the browser using the standard HTTP mechanism we can greatly simplify application code.

Unfortunately, in reality this is not the case. During its race to the top, HTTP lost part of its original vision, mainly due to implementation mistakes.

1. The specs failed to hit the sweet spot of authentication security. They standardized Basic Authentication which, by sending user and password in plain text, scared people to death and Digest which, due to its complexity and required server cooperation, never really caught on. A client-side mechanism with cheap yet reasonable security such as WSSE UsernameToken, later adopted by atom, would have been optimal.
2. Browsers took away login from client’s hands by showing the popup dialog to input user/password only after a 401 http error code from server. There should have been an always visible “login” button since the specs said “A user agent that wishes to authenticate itself with an origin server–usually, but not necessarily, after receiving a 401…”.
3. Browsers practically took away logout from client’s hands by requiring to close the browser in order to clean the passwords cache. There should have been an always visible “logout” button.
4. Browsers gave no chance to customize the ugly and annoyingly modal login dialog. HTML and/or CSS could have been used.
5. Browsers gave no client-side storage needed to keep session data but again turned back to server with cookies. They should have given something like upcoming HTML5 localStorage and sessionStorage.

Now there’s not much that can be done short of a collaborative effort by all browser vendors. Meanwhile we can keep dealing with authentication in application code on the server, in a never ending pile of custom solutions, each one slightly different, for yet another pretty standard problem. A problem solved 15 years ago.

• Avoid for-in and forEach in favor of optimized while loops
• Before making modifications to a DOM node remove it and then re-insert it
• To insert multiple DOM nodes, first insert them into a Document Fragment and then add it to the DOM
• Join all scripts into a single file
• Load javascript files on demand

Let’s make it clear for once, execution speed is not a human problem, that’s what computers are for, they execute our commands fast. The human problem is programming speed and writing down clear, readable, maintainable commands aka programs. forEach loops make sense to me, they say “i want to do something on each item”, optimized while loops make sense to computers. If i want to add DOM nodes or modify one, i don’t care of removing it or document fragments, browsers care. To me it’s just noise. Almost all of the problems addressed by those techniques stem from lack of smartness in the browser, and that’s where fixes belong to, on the machine side. The fact that there are inept browser makers is no excuse. Fixes still belong to the machine, they’re repeatable and can be made automatic. We have a long history of programs automatically converting human friendly code to machine friendly code. They’re called compilers and the output either machine code or optimized javascript doesn’t matter.

So, learn about javascript performance since knowledge is always the way, but don’t turn yourself into a machine, you’d be an awful one. Use the tools and wait for browsers to catch up.

• Aptimize
• Closure Compiler
• YUI 3 use

If i had to award the best talk at GTAC 2009, the no-brainer choice would be Prof. Niklaus Wirth opening talk. That’s not surprising if you consider who the speaker is, one of the great pioneers of computer science in the field of programming languages. What’s most surprising to me is that he presented a (pre)historical review of problems which turned out to be incredibly relevant today and, somehow, forced me to reframe my understanding of testing.

Building on 1972 Dijkstra dismissal of software testing

program testing can be a very effective way to show the presence of bugs, but is hopelessly inadequate for showing their absence.

Wirth explained that testing is treating symptoms instead of the disease, with the disease being our failure to prove correctness of programs by analytical means. This failure has its roots in distant past but it still holds today with languages and tools too complex and unreliable. Languages and tools providing proper abstraction, really hiding the system beneath, would give us the simple and rigorous ground to make programs easy to prove correct, so that no testing would be needed. Unfortunately, this looks far from happening

Programming languages are further from being mathematically nice than they were 50 years ago! They’re huge and complicated. They contain big libraries, and most of a programmer’s time is spent finding and learning the right libraries.

and again

What progress has this field actually made? We still struggle with the same problems as 50 years ago: iteration times, debugging, scratching our heads trying to figure out what went wrong.

How insightful! Empirical evidence that computer science made no sizable improvement in software construction is everywhere. It’s like a hamster in a wheel, running nowhere. Why is that? Maybe, we’ve been piling leaky abstractions on leaky abstractions, apparently hiding information without really simplifying, to the point where progress is drowning in complexity.

Testing is a nice way to easily lay down executable specifications, yet it requires maintenance and quickly degrades as we try to cover more cases. But when we code we have the chance to write self-describing programs which are executable specifications, reducing the coverage of tests needed, ideally to zero.

What does it mean in practice? Whenever it’s possible one should aim at declarative code. Domain specific languages and functional programming come to mind. The point being, if a program matches closely its specification, what’s left to test?

def factorial(n)
    if n == 0
        1
    else
        n * factorial(n-1)
    end
end

Code katas, a term first coined by Pragmatic Programmer Dave Thomas, are small programming exercises geared to hone a specific programming skill. Traditionally, they tend to be algorithmic like parsing or visiting graphs but could as well aim to improve understanding of particular programming paradigms, like functional or object oriented, or a specific language. Also, as remarkably pointed out by Matteo, katas can be crafted to master a certain technology like web or database. While, as you may guess, Coding Dojos are sites, groups or communities which propose and maintain collections of katas hopefully with solutions and reviews.

So, how do you practice? I suggest you solve a kata, review your work, compare it to other solutions, share your code with others and discuss it. Then solve it again trying to take a different path, balance pros and cons, then solve it again and again, until you feel you internalized the essence of the problem. Finally, you can move to another kata. If it feels like a lot of work, then you got it right. No question mastership requires time and effort but, then again, masters are those destined for greatness.

Resources

• Katacasts
• 21 Code Katas by Dave Thomas
• Lots of Code Quizzes with Ruby Solutions
• Matteo Vaccari’s Technological Katas
• Coding Dojo Code Katas
• Corey Haines Video Solution in Ruby of String Template
• Uncle Bob Code Katas (search “kata”, ie bowling kata)
• Micah Martin on Code Katas and Video Solution in Ruby of Langton’s Ant
• Micah Martin’s BattleShip Tournament
• Google Code Jam
• Jeff Atwood on Code Katas
• Steve Yegge on Code Katas
  
• Peter Norvig on Deep Practice