"The right way of coding nodejs applications" prompts me to post some benchmarks
I was playing with a few days ago to answer this very question.
My benchmarks looked at the performance of using closures for asynchronous flow
control, where you are creating closures with each function call.
A common model for flow control is to use closures. Here is an example from the
delightful little `Step` library by Tim Caswell.
Step(
function readSelf() {
fs.readFile(__filename, this);
},
function capitalize(err, text) {
if (err) throw err;
return text.toUpperCase();
},
function showIt(err, newText) {
if (err) throw err;
console.log(newText);
}
);
I wanted to see how the creation of closures at function invocation would
compare to the use of an object, where the steps would be object member
functions and state would be preserved in `this`. Maybe creating an object would
be faster since the member functions are already created, they only need to be
assigned.
I created a JSPerf that tested closures versus prototypes for this use case.
http://jsperf.com/flow-control/3
The tests are not asynchronous. I only want to test the cost of creating the
closures versus creating the object and fussing with `this`.
Each function sums an array after after first popping the last element. The pop
is one step. The sum is another. There is no external flow control. The popper
function calls the sum function when it is done.
Looks like the prototype method might be slightly faster, but not fast enough to
make me want to explore using object member functions for flow control when
closures are familiar and easy to read.
Rough Edges
I did find an interesting case where if you assign a method to an object member,
as you might do during object creation, performance drops dramatically. This can
be seen in "Closure assigned to object property" and "Closure assigned to object
property, not called".
However, you can make the problem go away if you assign the function to a
variable, then assign the property using the function name. This can be seen in
"Closure assigned to object property via variable".
Also, performance in Firefox 13 is a different story. Using an object to model
flow is all kinds of faster.
Conclusions
Maybe closures are a work in progress with a few gotchas, but it's probably not
worth my time to create a convoluted new async pattern to second-guess V8.
--
Alan Gutierrez - http://twitter.com/bigeasy - http://github.com/bigeasy
--
Job Board: http://jobs.nodejs.org/
Posting guidelines:
https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines
You received this message because you are subscribed to the Google
Groups "nodejs" group.
To post to this group, send email to nodejs@googlegroups.com
To unsubscribe from this group, send email to
nodejs+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/nodejs?hl=en?hl=en
