Example Price Index listener

<?php

namespace Your\Module\Namespace\Listener;

use MySQLReplication\BinLog\BinLogSocketConnect;
use MySQLReplication\Config\ConfigBuilder;
use MySQLReplication\Event\DTO\UpdateRowsDTO;
use MySQLReplication\Event\EventSubscribers;
use MySQLReplication\MySQLReplicationFactory;

class ProductPriceUpdateListener extends EventSubscribers
{

    private $indexerFactory;

    public function __construct(
        IndexerFactory $indexerFactory
    ) {
        $this->indexerFactory = $indexerFactory;
    }

    public function onUpdate(UpdateRowsDTO $event)
    {
        if ($event->getTableMap()->getTable() === 'catalog_product_entity_decimal') {
            foreach ($event->getValues() as $value) {
                $oldData = $value->getBefore();
                $newData = $value->getAfter();
                $productId = $newData['entity_id'];

                if ($oldData['value'] !== $newData['value']) {
                    $this->triggerPartialReindex($productId);
                }
            }
        }
    }

    private function triggerPartialReindex($productId)
    {
        //Leave as reindexer or build your own customised indexer
        $indexer = $this->indexerFactory->create();
        $indexer->load('catalog_product_price');
        $indexer->reindexRow($productId);
    }
}

//Im being Lazy replace with proper code
class BinLogListener
{
    public function run()
    {
        //Im being lazy as its almost 1am, use $connection-getConfig or something more secure
        $config = (new ConfigBuilder())
            ->withHost('localhost')
            ->withUser('root')
            ->withPassword('your_password')
            ->withPort(3306)
            ->build();

        $binLogStream = new MySQLReplicationFactory($config);
        $productPriceUpdateListener = new ProductPriceUpdateListener();
        $binLogStream->registerSubscriber($productPriceUpdateListener);

        try {
            $binLogStream->run();
        } catch (BinLogSocketConnectException $e) {
            echo "Error: {$e->getMessage()}";
        }
    }
}

//add where ever you please.
$listener = new BinLogListener();
$listener->run();