nextcloud/lib/private/Files/ObjectStore/S3ObjectTrait.php

<?php
/**
 * @copyright Copyright (c) 2017 Robin Appelman <robin@icewind.nl>
 * @author Christoph Wurst <christoph@winzerhof-wurst.at>
 * @author Florent <florent@coppint.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <robin@icewind.nl>
 * @author Roeland Jago Douma <roeland@famdouma.nl>
 * @license GNU AGPL version 3 or any later version
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

namespace OC\Files\ObjectStore;

use Aws\S3\Exception\S3MultipartUploadException;
use Aws\S3\MultipartUploader;
use Aws\S3\ObjectUploader;
use Aws\S3\S3Client;
use Icewind\Streams\CallbackWrapper;
use OC\Files\Stream\SeekableHttpStream;

trait S3ObjectTrait
{
    /**
     * Returns the connection.
     *
     * @return S3Client connected client
     *
     * @throws \Exception if connection could not be made
     */
    abstract protected function getConnection();

    /* compute configured encryption headers for put operations */
    abstract protected function getSseKmsPutParameters();

    /* compute configured encryption headers for get operations */
    abstract protected function getSseKmsGetParameters();

    /**
     * @param string $urn the unified resource name used to identify the object
     *
     * @return resource stream with the read data
     *
     * @throws \Exception when something goes wrong, message will be logged
     *
     * @since 7.0.0
     */
    public function readObject($urn)
    {
        return SeekableHttpStream::open(function ($range) use ($urn) {
            $s3params = [
                'Bucket' => $this->bucket,
                'Key' => $urn,
                'Range' => 'bytes='.$range,
            ] + $this->getSseKmsGetParameters();
            $command = $this->getConnection()->getCommand('GetObject', $s3params);
            $request = \Aws\serialize($command);
            $headers = [];
            foreach ($request->getHeaders() as $key => $values) {
                foreach ($values as $value) {
                    $headers[] = "$key: $value";
                }
            }
            $opts = [
                'http' => [
                    'protocol_version' => 1.1,
                    'header' => $headers,
                ],
            ];

            $context = stream_context_create($opts);

            return fopen($request->getUri(), 'r', false, $context);
        });
    }

    /**
     * @param string $urn the unified resource name used to identify the object
     * @param resource $stream stream with the data to write
     * @param string|null $mimetype the mimetype to set for the remove object @since 22.0.0
     * @throws \Exception when something goes wrong, message will be logged
     * @since 7.0.0
     */
    public function writeObject($urn, $stream, string $mimetype = null)
    {
        $count = 0;
        $countStream = CallbackWrapper::wrap($stream, function ($read) use (&$count) {
            $count += $read;
        });

        $s3params = [
            'part_size' => $this->uploadPartSize,
            'params' => [
                'ContentType' => $mimetype
            ] + $this->getSseKmsPutParameters(),
        ];

        // maybe, we should also use ObjectUploader here in the future
        // it does direct uploads for small files < 5MB and multipart otherwise
        $uploader = new ObjectUploader($this->getConnection(), $this->bucket, $urn, $countStream, 'private', $s3params);

        try {
            $uploader->upload();
        } catch (S3MultipartUploadException $e) {
            // if anything goes wrong with multipart, make sure that you don´t poison s3 bucket with fragments
            $this->getConnection()->abortMultipartUpload($uploader->getState()->getId());
            throw $e;
        } finally {
            // this handles [S3] fclose(): supplied resource is not a valid stream resource #23373
            // see https://stackoverflow.com/questions/11247507/fclose-18-is-not-a-valid-stream-resource/11247555
            // which also recommends the solution
            if (is_resource($countStream)) {
                fclose($countStream);
            }
        }
    }

    /**
     * @param string $urn the unified resource name used to identify the object
     *
     * @return void
     *
     * @throws \Exception when something goes wrong, message will be logged
     *
     * @since 7.0.0
     */
    public function deleteObject($urn)
    {
        $this->getConnection()->deleteObject([
            'Bucket' => $this->bucket,
            'Key' => $urn,
        ]);
    }

    public function objectExists($urn)
    {
        return $this->getConnection()->doesObjectExist($this->bucket, $urn);
    }
    
    /**
     * S3 copy command with SSE KMS key handling.
     */
    public function copyObject($from, $to)
    {
        $this->getConnection()->copy($this->getBucket(), $from, $this->getBucket(), $to, 'private', [
            'params' => $this->getSseKmsPutParameters(),
        ]);
    }
}