annotate core/modules/jsonapi/src/Controller/TemporaryJsonapiFileFieldUploader.php @ 19:fa3358dc1485 tip

Add ndrum files
author Chris Cannam
date Wed, 28 Aug 2019 13:14:47 +0100
parents af1871eacc83
children
rev   line source
Chris@18 1 <?php
Chris@18 2
Chris@18 3 namespace Drupal\jsonapi\Controller;
Chris@18 4
Chris@18 5 use Drupal\Component\Utility\Bytes;
Chris@18 6 use Drupal\Component\Utility\Crypt;
Chris@18 7 use Drupal\Component\Utility\Environment;
Chris@18 8 use Drupal\Core\Entity\EntityInterface;
Chris@18 9 use Drupal\Core\Entity\Plugin\DataType\EntityAdapter;
Chris@18 10 use Drupal\Core\Field\FieldDefinitionInterface;
Chris@18 11 use Drupal\Core\File\Exception\FileException;
Chris@18 12 use Drupal\Core\Validation\DrupalTranslator;
Chris@18 13 use Drupal\file\FileInterface;
Chris@18 14 use Drupal\Core\File\FileSystemInterface;
Chris@18 15 use Drupal\Core\Config\ConfigFactoryInterface;
Chris@18 16 use Drupal\Core\Lock\LockBackendInterface;
Chris@18 17 use Drupal\Core\Render\BubbleableMetadata;
Chris@18 18 use Drupal\Core\Session\AccountInterface;
Chris@18 19 use Drupal\Core\Utility\Token;
Chris@18 20 use Drupal\Component\Render\PlainTextOutput;
Chris@18 21 use Drupal\file\Entity\File;
Chris@18 22 use Drupal\file\Plugin\Field\FieldType\FileFieldItemList;
Chris@18 23 use Psr\Log\LoggerInterface;
Chris@18 24 use Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface;
Chris@18 25 use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
Chris@18 26 use Symfony\Component\HttpFoundation\Request;
Chris@18 27 use Symfony\Component\HttpKernel\Exception\HttpException;
Chris@18 28 use Symfony\Component\Validator\ConstraintViolation;
Chris@18 29
Chris@18 30 /**
Chris@18 31 * Reads data from an upload stream and creates a corresponding file entity.
Chris@18 32 *
Chris@18 33 * This is implemented at the field level for the following reasons:
Chris@18 34 * - Validation for uploaded files is tied to fields (allowed extensions, max
Chris@18 35 * size, etc..).
Chris@18 36 * - The actual files do not need to be stored in another temporary location,
Chris@18 37 * to be later moved when they are referenced from a file field.
Chris@18 38 * - Permission to upload a file can be determined by a user's field- and
Chris@18 39 * entity-level access.
Chris@18 40 *
Chris@18 41 * @internal This will be removed once https://www.drupal.org/project/drupal/issues/2940383 lands.
Chris@18 42 */
Chris@18 43 class TemporaryJsonapiFileFieldUploader {
Chris@18 44
Chris@18 45 /**
Chris@18 46 * The regex used to extract the filename from the content disposition header.
Chris@18 47 *
Chris@18 48 * @var string
Chris@18 49 */
Chris@18 50 const REQUEST_HEADER_FILENAME_REGEX = '@\bfilename(?<star>\*?)=\"(?<filename>.+)\"@';
Chris@18 51
Chris@18 52 /**
Chris@18 53 * The amount of bytes to read in each iteration when streaming file data.
Chris@18 54 *
Chris@18 55 * @var int
Chris@18 56 */
Chris@18 57 const BYTES_TO_READ = 8192;
Chris@18 58
Chris@18 59 /**
Chris@18 60 * A logger instance.
Chris@18 61 *
Chris@18 62 * @var \Psr\Log\LoggerInterface
Chris@18 63 */
Chris@18 64 protected $logger;
Chris@18 65
Chris@18 66 /**
Chris@18 67 * The file system service.
Chris@18 68 *
Chris@18 69 * @var \Drupal\Core\File\FileSystemInterface
Chris@18 70 */
Chris@18 71 protected $fileSystem;
Chris@18 72
Chris@18 73 /**
Chris@18 74 * The MIME type guesser.
Chris@18 75 *
Chris@18 76 * @var \Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface
Chris@18 77 */
Chris@18 78 protected $mimeTypeGuesser;
Chris@18 79
Chris@18 80 /**
Chris@18 81 * The token replacement instance.
Chris@18 82 *
Chris@18 83 * @var \Drupal\Core\Utility\Token
Chris@18 84 */
Chris@18 85 protected $token;
Chris@18 86
Chris@18 87 /**
Chris@18 88 * The lock service.
Chris@18 89 *
Chris@18 90 * @var \Drupal\Core\Lock\LockBackendInterface
Chris@18 91 */
Chris@18 92 protected $lock;
Chris@18 93
Chris@18 94 /**
Chris@18 95 * System file configuration.
Chris@18 96 *
Chris@18 97 * @var \Drupal\Core\Config\ImmutableConfig
Chris@18 98 */
Chris@18 99 protected $systemFileConfig;
Chris@18 100
Chris@18 101 /**
Chris@18 102 * Constructs a FileUploadResource instance.
Chris@18 103 *
Chris@18 104 * @param \Psr\Log\LoggerInterface $logger
Chris@18 105 * A logger instance.
Chris@18 106 * @param \Drupal\Core\File\FileSystemInterface $file_system
Chris@18 107 * The file system service.
Chris@18 108 * @param \Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface $mime_type_guesser
Chris@18 109 * The MIME type guesser.
Chris@18 110 * @param \Drupal\Core\Utility\Token $token
Chris@18 111 * The token replacement instance.
Chris@18 112 * @param \Drupal\Core\Lock\LockBackendInterface $lock
Chris@18 113 * The lock service.
Chris@18 114 * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
Chris@18 115 * The config factory.
Chris@18 116 */
Chris@18 117 public function __construct(LoggerInterface $logger, FileSystemInterface $file_system, MimeTypeGuesserInterface $mime_type_guesser, Token $token, LockBackendInterface $lock, ConfigFactoryInterface $config_factory) {
Chris@18 118 $this->logger = $logger;
Chris@18 119 $this->fileSystem = $file_system;
Chris@18 120 $this->mimeTypeGuesser = $mime_type_guesser;
Chris@18 121 $this->token = $token;
Chris@18 122 $this->lock = $lock;
Chris@18 123 $this->systemFileConfig = $config_factory->get('system.file');
Chris@18 124 }
Chris@18 125
Chris@18 126 /**
Chris@18 127 * Creates and validates a file entity for a file field from a file stream.
Chris@18 128 *
Chris@18 129 * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
Chris@18 130 * The field definition of the field for which the file is to be uploaded.
Chris@18 131 * @param string $filename
Chris@18 132 * The name of the file.
Chris@18 133 * @param \Drupal\Core\Session\AccountInterface $owner
Chris@18 134 * The owner of the file. Note, it is the responsibility of the caller to
Chris@18 135 * enforce access.
Chris@18 136 *
Chris@18 137 * @return \Drupal\file\FileInterface|\Drupal\Core\Entity\EntityConstraintViolationListInterface
Chris@18 138 * The newly uploaded file entity, or a list of validation constraint
Chris@18 139 * violations
Chris@18 140 *
Chris@18 141 * @throws \Symfony\Component\HttpKernel\Exception\HttpException
Chris@18 142 * Thrown when temporary files cannot be written, a lock cannot be acquired,
Chris@18 143 * or when temporary files cannot be moved to their new location.
Chris@18 144 */
Chris@18 145 public function handleFileUploadForField(FieldDefinitionInterface $field_definition, $filename, AccountInterface $owner) {
Chris@18 146 assert(is_a($field_definition->getClass(), FileFieldItemList::class, TRUE));
Chris@18 147 $destination = $this->getUploadLocation($field_definition->getSettings());
Chris@18 148
Chris@18 149 // Check the destination file path is writable.
Chris@18 150 if (!$this->fileSystem->prepareDirectory($destination, FileSystemInterface::CREATE_DIRECTORY)) {
Chris@18 151 throw new HttpException(500, 'Destination file path is not writable');
Chris@18 152 }
Chris@18 153
Chris@18 154 $validators = $this->getUploadValidators($field_definition);
Chris@18 155
Chris@18 156 $prepared_filename = $this->prepareFilename($filename, $validators);
Chris@18 157
Chris@18 158 // Create the file.
Chris@18 159 $file_uri = "{$destination}/{$prepared_filename}";
Chris@18 160
Chris@18 161 $temp_file_path = $this->streamUploadData();
Chris@18 162
Chris@18 163 $file_uri = $this->fileSystem->getDestinationFilename($file_uri, FileSystemInterface::EXISTS_RENAME);
Chris@18 164
Chris@18 165 // Lock based on the prepared file URI.
Chris@18 166 $lock_id = $this->generateLockIdFromFileUri($file_uri);
Chris@18 167
Chris@18 168 if (!$this->lock->acquire($lock_id)) {
Chris@18 169 throw new HttpException(503, sprintf('File "%s" is already locked for writing.'), NULL, ['Retry-After' => 1]);
Chris@18 170 }
Chris@18 171
Chris@18 172 // Begin building file entity.
Chris@18 173 $file = File::create([]);
Chris@18 174 $file->setOwnerId($owner->id());
Chris@18 175 $file->setFilename($prepared_filename);
Chris@18 176 $file->setMimeType($this->mimeTypeGuesser->guess($prepared_filename));
Chris@18 177 $file->setFileUri($file_uri);
Chris@18 178 // Set the size. This is done in File::preSave() but we validate the file
Chris@18 179 // before it is saved.
Chris@18 180 $file->setSize(@filesize($temp_file_path));
Chris@18 181
Chris@18 182 // Validate the file entity against entity-level validation and field-level
Chris@18 183 // validators.
Chris@18 184 $violations = $this->validate($file, $validators);
Chris@18 185 if ($violations->count() > 0) {
Chris@18 186 return $violations;
Chris@18 187 }
Chris@18 188
Chris@18 189 // Move the file to the correct location after validation. Use
Chris@18 190 // FILE_EXISTS_ERROR as the file location has already been determined above
Chris@18 191 // in FileSystem::getDestinationFilename().
Chris@18 192 try {
Chris@18 193 $this->fileSystem->move($temp_file_path, $file_uri, FileSystemInterface::EXISTS_ERROR);
Chris@18 194 }
Chris@18 195 catch (FileException $e) {
Chris@18 196 throw new HttpException(500, 'Temporary file could not be moved to file location');
Chris@18 197 }
Chris@18 198
Chris@18 199 $file->save();
Chris@18 200
Chris@18 201 $this->lock->release($lock_id);
Chris@18 202
Chris@18 203 return $file;
Chris@18 204 }
Chris@18 205
Chris@18 206 /**
Chris@18 207 * Validates and extracts the filename from the Content-Disposition header.
Chris@18 208 *
Chris@18 209 * @param \Symfony\Component\HttpFoundation\Request $request
Chris@18 210 * The request object.
Chris@18 211 *
Chris@18 212 * @return string
Chris@18 213 * The filename extracted from the header.
Chris@18 214 *
Chris@18 215 * @throws \Symfony\Component\HttpKernel\Exception\BadRequestHttpException
Chris@18 216 * Thrown when the 'Content-Disposition' request header is invalid.
Chris@18 217 */
Chris@18 218 public function validateAndParseContentDispositionHeader(Request $request) {
Chris@18 219 // First, check the header exists.
Chris@18 220 if (!$request->headers->has('content-disposition')) {
Chris@18 221 throw new BadRequestHttpException('"Content-Disposition" header is required. A file name in the format "filename=FILENAME" must be provided.');
Chris@18 222 }
Chris@18 223
Chris@18 224 $content_disposition = $request->headers->get('content-disposition');
Chris@18 225
Chris@18 226 // Parse the header value. This regex does not allow an empty filename.
Chris@18 227 // i.e. 'filename=""'. This also matches on a word boundary so other keys
Chris@18 228 // like 'not_a_filename' don't work.
Chris@18 229 if (!preg_match(static::REQUEST_HEADER_FILENAME_REGEX, $content_disposition, $matches)) {
Chris@18 230 throw new BadRequestHttpException('No filename found in "Content-Disposition" header. A file name in the format "filename=FILENAME" must be provided.');
Chris@18 231 }
Chris@18 232
Chris@18 233 // Check for the "filename*" format. This is currently unsupported.
Chris@18 234 if (!empty($matches['star'])) {
Chris@18 235 throw new BadRequestHttpException('The extended "filename*" format is currently not supported in the "Content-Disposition" header.');
Chris@18 236 }
Chris@18 237
Chris@18 238 // Don't validate the actual filename here, that will be done by the upload
Chris@18 239 // validators in validate().
Chris@18 240 // @see \Drupal\file\Plugin\rest\resource\FileUploadResource::validate()
Chris@18 241 $filename = $matches['filename'];
Chris@18 242
Chris@18 243 // Make sure only the filename component is returned. Path information is
Chris@18 244 // stripped as per https://tools.ietf.org/html/rfc6266#section-4.3.
Chris@18 245 return $this->fileSystem->basename($filename);
Chris@18 246 }
Chris@18 247
Chris@18 248 /**
Chris@18 249 * Checks if the current user has access to upload the file.
Chris@18 250 *
Chris@18 251 * @param \Drupal\Core\Session\AccountInterface $account
Chris@18 252 * The account for which file upload access should be checked.
Chris@18 253 * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
Chris@18 254 * The field definition for which to get validators.
Chris@18 255 * @param \Drupal\Core\Entity\EntityInterface $entity
Chris@18 256 * (optional) The entity to which the file is to be uploaded, if it exists.
Chris@18 257 * If the entity does not exist and it is not given, create access to the
Chris@18 258 * file will be checked.
Chris@18 259 *
Chris@18 260 * @return \Drupal\Core\Access\AccessResultInterface
Chris@18 261 * The file upload access result.
Chris@18 262 */
Chris@18 263 public static function checkFileUploadAccess(AccountInterface $account, FieldDefinitionInterface $field_definition, EntityInterface $entity = NULL) {
Chris@18 264 assert(is_null($entity) || $field_definition->getTargetEntityTypeId() === $entity->getEntityTypeId() && $field_definition->getTargetBundle() === $entity->bundle());
Chris@18 265 $entity_type_manager = \Drupal::entityTypeManager();
Chris@18 266 $entity_access_control_handler = $entity_type_manager->getAccessControlHandler($field_definition->getTargetEntityTypeId());
Chris@18 267 $bundle = $entity_type_manager->getDefinition($field_definition->getTargetEntityTypeId())->hasKey('bundle') ? $field_definition->getTargetBundle() : NULL;
Chris@18 268 $entity_access_result = $entity
Chris@18 269 ? $entity_access_control_handler->access($entity, 'update', $account, TRUE)
Chris@18 270 : $entity_access_control_handler->createAccess($bundle, $account, [], TRUE);
Chris@18 271 $field_access_result = $entity_access_control_handler->fieldAccess('edit', $field_definition, NULL, NULL, TRUE);
Chris@18 272 return $entity_access_result->andIf($field_access_result);
Chris@18 273 }
Chris@18 274
Chris@18 275 /**
Chris@18 276 * Streams file upload data to temporary file and moves to file destination.
Chris@18 277 *
Chris@18 278 * @return string
Chris@18 279 * The temp file path.
Chris@18 280 *
Chris@18 281 * @throws \Symfony\Component\HttpKernel\Exception\HttpException
Chris@18 282 * Thrown when input data cannot be read, the temporary file cannot be
Chris@18 283 * opened, or the temporary file cannot be written.
Chris@18 284 */
Chris@18 285 protected function streamUploadData() {
Chris@18 286 // 'rb' is needed so reading works correctly on Windows environments too.
Chris@18 287 $file_data = fopen('php://input', 'rb');
Chris@18 288
Chris@18 289 $temp_file_path = $this->fileSystem->tempnam('temporary://', 'file');
Chris@18 290 $temp_file = fopen($temp_file_path, 'wb');
Chris@18 291
Chris@18 292 if ($temp_file) {
Chris@18 293 while (!feof($file_data)) {
Chris@18 294 $read = fread($file_data, static::BYTES_TO_READ);
Chris@18 295
Chris@18 296 if ($read === FALSE) {
Chris@18 297 // Close the file streams.
Chris@18 298 fclose($temp_file);
Chris@18 299 fclose($file_data);
Chris@18 300 $this->logger->error('Input data could not be read');
Chris@18 301 throw new HttpException(500, 'Input file data could not be read.');
Chris@18 302 }
Chris@18 303
Chris@18 304 if (fwrite($temp_file, $read) === FALSE) {
Chris@18 305 // Close the file streams.
Chris@18 306 fclose($temp_file);
Chris@18 307 fclose($file_data);
Chris@18 308 $this->logger->error('Temporary file data for "%path" could not be written', ['%path' => $temp_file_path]);
Chris@18 309 throw new HttpException(500, 'Temporary file data could not be written.');
Chris@18 310 }
Chris@18 311 }
Chris@18 312
Chris@18 313 // Close the temp file stream.
Chris@18 314 fclose($temp_file);
Chris@18 315 }
Chris@18 316 else {
Chris@18 317 // Close the input file stream since we can't proceed with the upload.
Chris@18 318 // Don't try to close $temp_file since it's FALSE at this point.
Chris@18 319 fclose($file_data);
Chris@18 320 $this->logger->error('Temporary file "%path" could not be opened for file upload.', ['%path' => $temp_file_path]);
Chris@18 321 throw new HttpException(500, 'Temporary file could not be opened');
Chris@18 322 }
Chris@18 323
Chris@18 324 // Close the input stream.
Chris@18 325 fclose($file_data);
Chris@18 326
Chris@18 327 return $temp_file_path;
Chris@18 328 }
Chris@18 329
Chris@18 330 /**
Chris@18 331 * Validates the file.
Chris@18 332 *
Chris@18 333 * @param \Drupal\file\FileInterface $file
Chris@18 334 * The file entity to validate.
Chris@18 335 * @param array $validators
Chris@18 336 * An array of upload validators to pass to file_validate().
Chris@18 337 *
Chris@18 338 * @return \Drupal\Core\Entity\EntityConstraintViolationListInterface
Chris@18 339 * The list of constraint violations, if any.
Chris@18 340 */
Chris@18 341 protected function validate(FileInterface $file, array $validators) {
Chris@18 342 $violations = $file->validate();
Chris@18 343
Chris@18 344 // Remove violations of inaccessible fields as they cannot stem from our
Chris@18 345 // changes.
Chris@18 346 $violations->filterByFieldAccess();
Chris@18 347
Chris@18 348 // Validate the file based on the field definition configuration.
Chris@18 349 $errors = file_validate($file, $validators);
Chris@18 350 if (!empty($errors)) {
Chris@18 351 $translator = new DrupalTranslator();
Chris@18 352 foreach ($errors as $error) {
Chris@18 353 $violation = new ConstraintViolation($translator->trans($error),
Chris@18 354 $error,
Chris@18 355 [],
Chris@18 356 EntityAdapter::createFromEntity($file),
Chris@18 357 '',
Chris@18 358 NULL
Chris@18 359 );
Chris@18 360 $violations->add($violation);
Chris@18 361 }
Chris@18 362 }
Chris@18 363
Chris@18 364 return $violations;
Chris@18 365 }
Chris@18 366
Chris@18 367 /**
Chris@18 368 * Prepares the filename to strip out any malicious extensions.
Chris@18 369 *
Chris@18 370 * @param string $filename
Chris@18 371 * The file name.
Chris@18 372 * @param array $validators
Chris@18 373 * The array of upload validators.
Chris@18 374 *
Chris@18 375 * @return string
Chris@18 376 * The prepared/munged filename.
Chris@18 377 */
Chris@18 378 protected function prepareFilename($filename, array &$validators) {
Chris@18 379 if (!empty($validators['file_validate_extensions'][0])) {
Chris@18 380 // If there is a file_validate_extensions validator and a list of
Chris@18 381 // valid extensions, munge the filename to protect against possible
Chris@18 382 // malicious extension hiding within an unknown file type. For example,
Chris@18 383 // "filename.html.foo".
Chris@18 384 $filename = file_munge_filename($filename, $validators['file_validate_extensions'][0]);
Chris@18 385 }
Chris@18 386
Chris@18 387 // Rename potentially executable files, to help prevent exploits (i.e. will
Chris@18 388 // rename filename.php.foo and filename.php to filename.php.foo.txt and
Chris@18 389 // filename.php.txt, respectively). Don't rename if 'allow_insecure_uploads'
Chris@18 390 // evaluates to TRUE.
Chris@18 391 if (!$this->systemFileConfig->get('allow_insecure_uploads') && preg_match(FILE_INSECURE_EXTENSION_REGEX, $filename) && (substr($filename, -4) != '.txt')) {
Chris@18 392 // The destination filename will also later be used to create the URI.
Chris@18 393 $filename .= '.txt';
Chris@18 394
Chris@18 395 // The .txt extension may not be in the allowed list of extensions. We
Chris@18 396 // have to add it here or else the file upload will fail.
Chris@18 397 if (!empty($validators['file_validate_extensions'][0])) {
Chris@18 398 $validators['file_validate_extensions'][0] .= ' txt';
Chris@18 399 }
Chris@18 400 }
Chris@18 401
Chris@18 402 return $filename;
Chris@18 403 }
Chris@18 404
Chris@18 405 /**
Chris@18 406 * Determines the URI for a file field.
Chris@18 407 *
Chris@18 408 * @param array $settings
Chris@18 409 * The array of field settings.
Chris@18 410 *
Chris@18 411 * @return string
Chris@18 412 * An un-sanitized file directory URI with tokens replaced. The result of
Chris@18 413 * the token replacement is then converted to plain text and returned.
Chris@18 414 */
Chris@18 415 protected function getUploadLocation(array $settings) {
Chris@18 416 $destination = trim($settings['file_directory'], '/');
Chris@18 417
Chris@18 418 // Replace tokens. As the tokens might contain HTML we convert it to plain
Chris@18 419 // text.
Chris@18 420 $destination = PlainTextOutput::renderFromHtml($this->token->replace($destination, [], [], new BubbleableMetadata()));
Chris@18 421 return $settings['uri_scheme'] . '://' . $destination;
Chris@18 422 }
Chris@18 423
Chris@18 424 /**
Chris@18 425 * Retrieves the upload validators for a field definition.
Chris@18 426 *
Chris@18 427 * This is copied from \Drupal\file\Plugin\Field\FieldType\FileItem as there
Chris@18 428 * is no entity instance available here that that a FileItem would exist for.
Chris@18 429 *
Chris@18 430 * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
Chris@18 431 * The field definition for which to get validators.
Chris@18 432 *
Chris@18 433 * @return array
Chris@18 434 * An array suitable for passing to file_save_upload() or the file field
Chris@18 435 * element's '#upload_validators' property.
Chris@18 436 */
Chris@18 437 protected function getUploadValidators(FieldDefinitionInterface $field_definition) {
Chris@18 438 $validators = [
Chris@18 439 // Add in our check of the file name length.
Chris@18 440 'file_validate_name_length' => [],
Chris@18 441 ];
Chris@18 442 $settings = $field_definition->getSettings();
Chris@18 443
Chris@18 444 // Cap the upload size according to the PHP limit.
Chris@18 445 $max_filesize = Bytes::toInt(Environment::getUploadMaxSize());
Chris@18 446 if (!empty($settings['max_filesize'])) {
Chris@18 447 $max_filesize = min($max_filesize, Bytes::toInt($settings['max_filesize']));
Chris@18 448 }
Chris@18 449
Chris@18 450 // There is always a file size limit due to the PHP server limit.
Chris@18 451 $validators['file_validate_size'] = [$max_filesize];
Chris@18 452
Chris@18 453 // Add the extension check if necessary.
Chris@18 454 if (!empty($settings['file_extensions'])) {
Chris@18 455 $validators['file_validate_extensions'] = [$settings['file_extensions']];
Chris@18 456 }
Chris@18 457
Chris@18 458 return $validators;
Chris@18 459 }
Chris@18 460
Chris@18 461 /**
Chris@18 462 * Generates a lock ID based on the file URI.
Chris@18 463 *
Chris@18 464 * @param string $file_uri
Chris@18 465 * The file URI.
Chris@18 466 *
Chris@18 467 * @return string
Chris@18 468 * The generated lock ID.
Chris@18 469 */
Chris@18 470 protected static function generateLockIdFromFileUri($file_uri) {
Chris@18 471 return 'file:jsonapi:' . Crypt::hashBase64($file_uri);
Chris@18 472 }
Chris@18 473
Chris@18 474 }