CodeIgniter - Application Profiling

When building a web application, we are very much concerned about the performance of the website in terms of how much time the controller took to execute and how much memory is used. Not only the performance, but we also need to see the insights of data like POST data, data of database queries, session data etc.
for debugging purpose while developing some application. CodeIgniter has made this job easier for us by profiling an application.

Enable Profiling

To enable profiling of your application, simply execute the command given below in any of the method of your controller.

$this->output->enable_profiler(TRUE);

The report of the profiling can be seen at the bottom of the page after enabling it.

Disable Profiling

To disable profiling of your application, simply execute the command given below in any of the method of your controller.

$this->output->enable_profiler(FALSE);

Enable / Disable Profiler Section

Profiling can be done on section basis. You can enable or disable profiling of a section by setting a Boolean value TRUE or FALSE. If you want to set profiling on the application then you can do in a file located in application/config/profiler.php
For example, the following command will enable profiling queries for the whole application.

$config['queries'] = TRUE;

In the following table, the key is the parameter, which can be set in the config array to enable or disable a particular profile.

Key	Description	Default
benchmarks	Elapsed time of Benchmark points and total execution time	TRUE
config	CodeIgniterConfig variables	TRUE
controller_info	The Controller class and method requested	TRUE
get	Any GET data passed in the request	TRUE
http_headers	The HTTP headers for the current request	TRUE
memory_usage	Amount of memory consumed by the current request, in bytes	TRUE
post	Any POST data passed in the request	TRUE
queries	Listing of all database queries executed, including execution time	TRUE
uri_string	The URI of the current request	TRUE
session_data	Data stored in the current session	TRUE
query_toggle_count	The number of queries after which the query block will default to hidden.	25

The profiler set in the file in application/config/profiler.php can be overridden by using the set_profiler_sections() function in controllers as shown below.

$sections = array( 
   'config'  => TRUE, 
   'queries' => TRUE 
); 
 
$this->output->set_profiler_sections($sections);