The purpose of a log processor is (usually) to modify a log record or add more detailed information to it.
Log processors allow you to manipulate log records without changing the code that actually calls the log method (inversion of control). This enables you to add any information from outside the scope of the actual calling function, such as webserver environment variables. The TYPO3 Core ships with some basic log processors, but more can be added with extensions.
This section describes the log processors that are shipped with the TYPO3 Core. Some processors have options to allow the customization of the particular processor. See the Configuration section for how to use these options.
The introspection processor adds backtrace data about where the log event was triggered.
By default, the following parameters from the original function call are added:
The absolute path to the file.
The line number.
The class name.
The function name.
The memory usage processor adds the amount of used memory to the log record (result from memory_get_usage()).
Custom log processors can be added through extensions. Every log processor has to implement the interface EXT:core/Classes/Log/Processor/ProcessorInterface.php. It is suggested to extend the abstract class EXT:core/Classes/Log/Processor/AbstractProcessor.php which allows you use configuration options by adding the corresponding properties and setter methods.
Please keep in mind that TYPO3 will silently continue operating,
in case a log processor is throwing an exception while executing