def _get_requested_range(request: Request) -> Optional[Range]:
# http://svn.tools.ietf.org/svn/wg/httpbis/specs/rfc7233.html#rfc.section.3.1
# A server must ignore a Range header field received with a request method
# other than GET
if request.method != "GET":
return None
# NB: only the first Range request header is taken into consideration;
# if the HTTP contains several Range headers, only the first is used
range_header = request.get_first_header(b"range")
if not range_header:
return None
try:
value = Range.parse(range_header)
except InvalidRangeValue:
raise BadRequest("Invalid Range header")
else:
# An origin server must ignore a Range header field that contains
# a range unit it does not understand.
if value.unit != "bytes":
return None
return value
async def example_2():
# example: use an exception to control the execution flow,
# the error handler defined in app.exceptions_handlers will produce the
# response object
# the response object must be populated with CORS headers, otherwise the
# client won't expose the error details - for example we might send a JSON
# structure with error information
raise BadRequest("Some user friendly client error detail")
def converter(data):
try:
return expected_type(**data)
except TypeError as type_error:
raise BadRequest(
f"invalid parameter in request payload, " +
f"caused by type {_try_get_type_name(expected_type)} or " +
"one of its subproperties. Error: " +
_generalize_init_type_error_message(type_error))
def _default_bool_converter(value: str) -> bool:
if value in {"1", "true"}:
return True
if value in {"0", "false"}:
return False
# bad request: expected a bool value, but
# got something different that is not handled
raise BadRequest(f"Expected a bool value for a parameter, but got {value}.")
def _default_bool_converter(value: str):
if value in {'1', 'true'}:
return True
if value in {'0', 'false'}:
return False
# bad request: expected a bool value, but
# got something different that is not handled
raise BadRequest()
def parse_value(value, desired_type: type, param_name: str):
try:
if desired_type is bool:
return bool(int(value))
if desired_type in {int, float}:
return desired_type(value)
return value
except ValueError:
raise BadRequest(
f'invalid parameter "{param_name}". '
f'The value cannot be parsed as {desired_type.__name__}.')
def __call__(self, request):
value = get_param(request, self.name)
if value is None or value == '':
if self.is_optional:
return None
raise BadRequest(f'missing parameter: {self.name}.')
if self.annotation is str:
return unwrap(value)
return value
async def file_chunker() -> AsyncIterable[bytes]:
async with files_handler.open(file_path) as file:
for part in range_option:
if part.start is None and part.end is None:
raise BadRequest("Invalid range part: both boundaries are None")
if part.start is not None and part.end is not None:
# return a portion between start and end indexes
await file.seek(part.start, 0)
part_size = part.end - part.start
elif part.end is None:
assert part.start is not None
# return all bytes to the end, starting from start index
await file.seek(part.start)
part_size = file_size - part.start
elif part.start is None:
# return a number of units at the end of the file
await file.seek(file_size - part.end)
part_size = part.end
bytes_to_return = part_size
while True:
chunk_limit = (
size_limit if bytes_to_return > size_limit else bytes_to_return
)
chunk = await file.read(chunk_limit)
if not chunk:
break
bytes_to_return -= len(chunk)
if boundary:
yield b"--" + boundary + b"\r\n"
yield b"Content-Type: " + file_type + b"\r\n"
yield b"Content-Range: " + _get_content_range_value(
part, file_size
) + b"\r\n\r\n"
yield chunk
if boundary:
yield b"\r\n"
if boundary:
yield b"--" + boundary + b"--\r\n"
yield b""
async def get_value(self, request: Request) -> T:
raw_value = self.get_raw_value(request)
try:
value = self.converter(raw_value)
except (ValueError, BadRequest):
raise BadRequest(
f'Invalid value for parameter `{self.name}`; expected {self.expected_type}'
)
if value is None and self.required:
raise MissingParameterError(self.name, self.source_name)
if not self.required and self._empty_iterable(value):
return None
return value
async def get_value(self, request: Request) -> Optional[T]:
# TODO: support get_raw_value returning None, to not instantiate lists
# when a parameter is not present
raw_value = self.get_raw_value(request)
try:
value = self.converter(raw_value)
except (ValueError, BadRequest):
raise BadRequest(
f"Invalid value {raw_value} for parameter `{self.parameter_name}`; "
f"expected a valid {self.expected_type.__name__}."
)
if self.default is not empty and (value is None or self._empty_iterable(value)):
return None
if value is None and self.required and self.root_required:
raise MissingParameterError(self.parameter_name, self.source_name)
if not self.required and self._empty_iterable(value):
return None
return value
