Base64ContentEncoder.php

<?php
 
/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
 
namespace Symfony\Component\Mime\Encoder;
 
use Symfony\Component\Mime\Exception\RuntimeException;
 
final class Base64ContentEncoder extends Base64Encoder implements ContentEncoderInterface
{
    public function encodeByteStream($stream, int $maxLineLength = 0): iterable
    {
        if (!\is_resource($stream)) {
            throw new \TypeError(sprintf('Method "%s" takes a stream as a first argument.', __METHOD__));
        }
 
        $filter = stream_filter_append($stream, 'convert.base64-encode', STREAM_FILTER_READ, [
            'line-length' => 0 >= $maxLineLength || 76 < $maxLineLength ? 76 : $maxLineLength,
            'line-break-chars' => "\r\n",
        ]);
        if (!\is_resource($filter)) {
            throw new RuntimeException('Unable to set the base64 content encoder to the filter.');
        }
 
        if (stream_get_meta_data($stream)['seekable'] ?? false) {
            rewind($stream);
        }
        while (!feof($stream)) {
            yield fread($stream, 8192);
        }
        stream_filter_remove($filter);
    }
 
    public function getName(): string
    {
        return 'base64';
    }
}