Autoloading from file with several classes

Question

In my project structure I have the usual class per file separation and auto-loading is easy, but now I would like to group some small classes in a a single file, probably a file with the name of the current folder.

now:

|/module
|-Smallclass1.php
|-Smallclass2.php
|-Smallclass3.php
|-Normalclass.php

after:

|/module
|-module.php  <-- smallclasses go here
|-Normalclass.php

Now comes the debate. To autoload one 'SmallclassX' I was thinking to check if SmallclassX.php file exists if not check if module.php exists and if so, check if the class exists inside the file and include it. Including the whole module.php file when I need a single class seems an overhead specially if the file contains many classes. Here they suggest using tokens the check if the class exists, but I'm not sure about it's efficiency, after that I'll need a method to include only the class I need.

Do you think if I get to load only the class I need like I mentioned, will it be also an overhead because of reading the file more that once and looking inside to include the piece of code I want?

Answer 1

You can stack autoloaders using spl_autoload_register, allowing you to first attempt to load the class from a dedicated file, then falling back to including the module file afterwards (and if no autoloader can solve the dependency, error out normally). This will allow you to avoid all hacks by parsing tokens and other items, which will require a lot more than just require-ing the file and seeing what the result is afterwards.

I would however advice you to benchmark this solution. Whether it's more effective will depend on the delay for accessing the files (APC) and the cost of parsing and including each class seperately.

I'll also agree with the other comments, it might be confusing that you have two separate schemes for including classes, and APC will remove most of the cost of having separate files anyway.