Forem: Codeur Malin

Today I found a bug !

Codeur Malin — Fri, 24 Apr 2020 16:58:30 +0000

Hello,

I like coding, I do that everyday but something strange happened to me today. I work in a company that use extern library with API for his business and I have for mission to update a block that use one of this services with extra data.

Humm.. ok no problem. I'm used to doing this kind of things.
I start to read in the documentation of this library to find out me how it works, and.. Ok I show it.

I'm ready to code, I go in my terminal create a new branch from preprod and let's go.
Time flies, I see things take shape I'm glad but when I test I don't get what I expected. Oooookay I should miss something, I go to the documentation recheck if I forget something but no all look good.

OK maybe there are a dependencies problem ? I check my composer.. Yeah maybe if I update this one it will works. Let's go for that !

Still same errors grrr !

OK why you don't work *** !?
I don't have a great debugger to help me to find a solution but I saw all Rambo movies and I know what has to be done. I decide to put on a bandanna on my head and dump my request every place where he go to find where it goes wrong.

I started by putting dump in 2 places, first at the end of my code to show if I send correct data (just to be sure because in theorie I have already test that)
And the other place is directly in the library i use for make connection with this service, juste before the request is sent correctly.

So the first dump I have put, looks ok the data look like it's demand.
And the second, looks good too.. Damnit !

OK I'm confused, I don't know why it doesn't work but there are a fact it's doesn't works. Code isn't magic there are necessarily somewhere a thing who's going bad.
Well, let's try something else. Humm.. I will simulate the call with Postman maybe I will show a new errors message that can help me ?
So I do that and.. It works !

Wait.. what ?!
It works, but I do the same things.

To tell the truth at this moment I am nevertheless delighted to have a good result

Why in Postman it works but not when I execute my code ? I'm sure now my data are good so I check carefully every data send in the library are correct and.. voila I found It !!

I did not pay attention but the library convert boolean to integer and there goes the shit. It sounds futile but the typehint is very important.

So after discovery that bug, I went to the Github repository of that library and make a pull request with a little fix. Pending, I make a fork of this repository with the fix and use it directly in my project.

Today I found a bug and I tried to fix it !

And you have you already found a bug in a library ?

Thank for reading,
Codeur M

PHP Tips : How to use optimized built-it functions ?

Codeur Malin — Wed, 15 Apr 2020 15:43:26 +0000

Did you already use built-in function in PHP like count, strlen or in_array ?
I think so, these are essential but do you know there are some of these functions that can be executed faster !? Thanks to OpCode optimized.

OpCode you said ?

Yeah OpCode, you know this is the list of instructions that are generated when your php code is compiled and easier interpreted by the computer.

For exemple this code :


<?php

namespace foo;

$myString = 'This is my string !';
strlen($myString);

Will generate this OpCode :

line     #* E I O op                         fetch       ext  return  operands
--------------------------------------------------------------------------------
   5     0  E >   ASSIGN                                              !0, 'This+is+my+string+%21'
   6     1        INIT_NS_FCALL_BY_NAME                               'foo%5Cstrlen'
         2        SEND_VAR_EX                                         !0
         3        DO_FCALL                                 0          
         4      > RETURN                                              1

And some functions like strlen has is own opCode (you can see this in the next pictures at line 6)

line     #* E I O op            fetch          ext  return  operands
---------------------------------------------------------------------------
   5     0  E >   ASSIGN                                    !0, 'This+is+my+string+%21'
   6     1        STRLEN                            ~2      !0        
         2        FREE                                      ~2
         3      > RETURN                                    1

Instead of use a call to a function INIT_NS_FCALL_BY_NAME you can use the OpCode STRLEN directly that was optimized.

This OpCode is not use by default when you are in a namespace (like my exemple), if you want to use the optimized version you have to prefix your built-it function by a backslash \ like this : \strlen('foo bar').

To compare the performance of the two versions, I make a little script which use strlen in a loop with and without backslash and this is the result :

Not optimized strlen in a loop


<?php

namespace foo;

$bar = [];
for($i = 0; $i < 10000; $i++) {
    $bar[] = strlen('this is my string !'.$i);
}

Optimized \strlen always in a loop

<?php

namespace foo;

$bar = [];
for($i = 0; $i < 10000; $i++) {
    $bar[] = \strlen('this is my string !'.$i);
}

It's a micro optimization, but always good to take.
A list of opCode was introduced with PHP 7.0, you can see it bellow:

Most useful functions

Comparison functions

is_null
is_bool
is_long
is_int
is_integer
is_float
is_double
is_real
is_string
is_array
is_object
is_resource
is_callable

Cast functions

boolval
intval
floatval
doubleval
strval

Other functions

chr
ord
dirname
defined
constant
define
gettype
get_class
get_called_class
func_num_args
func_get_args
function_exists
extension_loaded
call_user_func_array
call_user_func
array_slice

If you don't like prefix your functions with a \ you can import the function with use function instead and enjoy the benefits of optimized code.

<?php

namespace foo;

use function strlen;

$myString = 'This is my string !';
strlen($myString);

You can use a tool like PHP-CS-FIXER to indicate in your code base which optimisations can be done and fix them, for optimized functions the option is native_function_invocation.

In conclusion, use the optimized functions as much as possible, it does not require much effort and can make your code more efficient.

Here is some links :

Thank you for reading,
Codeur Malin

PHP Tips : Pourquoi utiliser "continue" ?

Codeur Malin — Sat, 11 Apr 2020 18:12:15 +0000

Hello world !

Je vais vous présentez ici un petit tips en PHP mais qui peut facilement être adapté et utilisé dans d'autres langages qui va vous permettre d'avoir un code plus lisible lorsque vous utilisez des conditions à l'intérieur de boucles.

C'est bien évidemment l'utilisation du mot clé continue, comme indiqué dans le titre !

Donc continue est utilisé pour passer à l'itération suivante dans une boucle.
L'avantage premier de ce mot clé est ainsi d'aplatir le code quand il est utilisé avec une condition inversé.
Souvent il nous arrive d'avoir des conditions à l'intérieur d'une boucle mais la logique qu'on désire effectuer se trouve également dans cette condition. Le souci est alors d'avoir un niveau d'indentation élevé qui pourrait être évité avec l'utilisation de continue.

Voici un exemple ci-dessous :

// On veut afficher le nom des héros s'ils sont définis
$heroes = [
  ['name' => 'T Challa'],
  ['name' => 'Tony Stark'],
  ['name' => 'Bruce Wayne'],
  ...
];
// sans continue                 // avec continue
foreach($heroes as $hero) {    | foreach($heroes as $hero) {          
  if (isset($hero['name'])) {  |   if (!isset($hero['name'])) { // condition inversé
    echo $item['name'];        |     continue;
    ...                        |   }
  }                            |   echo $item['name'];
}                              |   ...
                               | }

Ici on voit qu'en utilisant une condition inversée + continue, on a la possibilité de sortir notre logique de la condition et donc d'avoir un niveau d'imbrication en moins. Ainsi, le code devient plus lisible surtout s'il y a plusieurs niveaux d'imbrication.

Merci d'avoir pris le temps de lire mon premier post 😃
Codeur M