File.orm.yml

App\Model\File:
    type: entity
    table: files
    entityListeners:
        App\Doctrine\EventListener\FileUploadListener:
            prePersist: [upload]
            preUpdate: [upload]
            preRemove: [remove]
    id:
        id:
            type: integer
            generator: { strategy: AUTO }
    fields:
        path:
            type: string

File.php

<?php

namespace App\Model;

use Symfony\Component\HttpFoundation\File\UploadedFile;

class File
{
    /**
     * @var int
     */
    protected $id;
    /**
     * @var UploadedFile|null
     */
    protected $file;
    /**
     * @var string
     */
    protected $path;

    /**
     * @return int
     */
    public function getId()
    {
        return $this->id;
    }

    public function setFile(UploadedFile $file = null)
    {
        $this->file = $file;

        return $this;
    }

    /**
     * @return UploadedFile
     */
    public function getFile()
    {
        return $this->file;
    }

    /**
     * @return string
     */
    public function getPath()
    {
        return $this->path;
    }

    /**
     * @param mixed $path
     *
     * @return $this
     */
    public function setPath($path)
    {
        $this->path = $path;

        return $this;
    }
}

FileUploadListener.php

<?php

namespace App\Doctrine\EventListener;

use App\Model\Image;

class FileUploadListener
{
    public function __construct($uploadDir)
    {
        $this->uploadDir = $uploadDir;
    }

    public function upload(Image $image)
    {
        if (null === $image->getFile()) {
            return;
        }

        $targetDir = $this->getTargetDir($image->getFile());
        $image->getFile()->move(
            sprintf('%s/%s', rtrim($this->uploadDir, '/'), $targetDir),
            $image->getFile()->getClientOriginalName()
        );

        $image->setPath(sprintf('%s/%s', $targetDir, $image->getFile()->getClientOriginalName()));

        $image->setFile(null);
    }

    public function remove(Image $image)
    {
        if (file_exists($image->getPath())) {
            unlink($image->getPath());
        }
    }

    private function getTargetDir(\SplFileInfo $file)
    {
        $checksum = hash('sha1', file_get_contents($file->getRealPath()));

        return sprintf('%s/%s/%s/%s/%s', substr($checksum, 0, 2), substr($checksum, 2, 2), substr($checksum, 4, 4), substr($checksum, 8, 4), $checksum);
    }
}

services.yml

services:
    doctrine.listener.file_upload:
        class: App\Doctrine\EventListener\FileUploadListener
        arguments: [%images_upload_dir%]
        tags:
            - { name: doctrine.orm.entity_listener }