undertaker

Get rid of your old and unused PHP code.

How it works

undertaker works by preloading all your classes in a given directory and then utilizes the krakjoe/tombs extension to keep track of the unused functions over time. It provides CLI and HTTP interface for querying the unused functions.

Prerequisites

• PHP 7.2+
• Target project managed by composer
• PHP files specified for preloading do not have side effects when loaded. For example, defining a class and invoking a function at the bottom of the file.

Setup

Enabling tombs

Make sure you have the tombs.so extension loaded and configured to serve the unused functions through TCP. An example tombs configuration file that has TCP listener is:

zend_extension=tombs.so
tombs.slots=10000
tombs.strings=64M
tombs.socket=tcp://0.0.0.0:12345
tombs.graveyard_format=function
tombs.namespace=Undertaker

Note: You will also have to have opcache enabled as there is a bug in the tombs extension which duplicates functions if it is not enabled.

Setting up the PHP preloader

1. Require nenad.dev/undertaker in your composer.json file.
2. Create a preloading file on the target system.

The preloading file must be accessible by the php-fpm process, so make sure it's on the same system. You can modify this file to load any directories you want by calling the Preloader::load method on all the directories you want to preload.

Run undertaker

Run undertaker with flags or environment variables pointing to:

• the tombs address (-tombs or TOMBS_ADDRESS, i.e. localhost:12345)
• the php-fpm address (-fpm or FPM_ADDRESS, i.e. localhost:9000)
• the path to the preload file from the last step (i.e. /var/http/web/undertaker.php)

If you want to enable the HTTP server from undertaker also run it with -port or HTTP_PORT env variable.

Wait for requests and collect unused functions

Sending a request to undertaker to /collect (or running the command with -collect flag) will return the functions which have not been yet used over the lifetime of the php-fpm process.

Example

This repository comes with an example. Simply run docker-compose up -d and you'll have bootstrapped and preloaded undertaker with the PHP repository found in docker/fpm/project.

Collecting functions right after undertaker has preloaded all the files:

> curl localhost:8888/collect
Undertaker\Dummy\Calculator\PriceCalculator::allRoomsPrice
Undertaker\Dummy\Calculator\PriceCalculator::total
Undertaker\Dummy\Model\House::__construct
Undertaker\Dummy\Model\House::rooms
Undertaker\Dummy\Model\House::exteriorType
Undertaker\Dummy\Model\Building::rooms
Undertaker\Dummy\Model\InhabitableInterface::exteriorType

Collecting after we've invoked the index.php file through nginx once:

> curl localhost:8888/collect
Undertaker\Dummy\Calculator\PriceCalculator::total
Undertaker\Dummy\Model\House::exteriorType
Undertaker\Dummy\Model\Building::rooms
Undertaker\Dummy\Model\InhabitableInterface::exteriorType

Future work

• Detect files which might have side effects when loaded
• Running in production...