Improving performance using PHP 7 enhancements

One trend that developers are taking advantage of is the use of anonymous functions. One classic problem, when dealing with anonymous functions, is to write them in such a way that any object can be bound to $this and the function will still work. The approach used in PHP 5 code is to use bindTo(). In PHP 7, a new method, call(), was added, which offers similar functionality, but vastly improved performance.

How to do it...

To take advantage of call(), execute an anonymous function in a lengthy loop. In this example, we will demonstrate an anonymous function, that scans through a log file, identifying IP addresses sorted by how frequently they appear:

1. First, we define a Application\Web\Access class. In the constructor, we accept a filename as an argument. The log file is opened as an SplFileObject and assigned to $this->log:

   Namespace Application\Web;
   
   use Exception;
   use SplFileObject;
   class Access
   {
     const ERROR_UNABLE = 'ERROR: unable...