sanic/sanic/handlers/content_range.py
Adam Hopkins 9cb9e88678
Establish basic file browser and index fallback (#2662)
Co-authored-by: L. Kärkkäinen <98187+Tronic@users.noreply.github.com>
Co-authored-by: L. Karkkainen <tronic@users.noreply.github.com>
2023-02-05 15:09:04 +02:00

79 lines
2.6 KiB
Python

from __future__ import annotations
from sanic.exceptions import (
HeaderNotFound,
InvalidRangeType,
RangeNotSatisfiable,
)
class ContentRangeHandler:
"""
A mechanism to parse and process the incoming request headers to
extract the content range information.
:param request: Incoming api request
:param stats: Stats related to the content
:type request: :class:`sanic.request.Request`
:type stats: :class:`posix.stat_result`
:ivar start: Content Range start
:ivar end: Content Range end
:ivar size: Length of the content
:ivar total: Total size identified by the :class:`posix.stat_result`
instance
:ivar ContentRangeHandler.headers: Content range header ``dict``
"""
__slots__ = ("start", "end", "size", "total", "headers")
def __init__(self, request, stats):
self.total = stats.st_size
_range = request.headers.getone("range", None)
if _range is None:
raise HeaderNotFound("Range Header Not Found")
unit, _, value = tuple(map(str.strip, _range.partition("=")))
if unit != "bytes":
raise InvalidRangeType(
"%s is not a valid Range Type" % (unit,), self
)
start_b, _, end_b = tuple(map(str.strip, value.partition("-")))
try:
self.start = int(start_b) if start_b else None
except ValueError:
raise RangeNotSatisfiable(
"'%s' is invalid for Content Range" % (start_b,), self
)
try:
self.end = int(end_b) if end_b else None
except ValueError:
raise RangeNotSatisfiable(
"'%s' is invalid for Content Range" % (end_b,), self
)
if self.end is None:
if self.start is None:
raise RangeNotSatisfiable(
"Invalid for Content Range parameters", self
)
else:
# this case represents `Content-Range: bytes 5-`
self.end = self.total - 1
else:
if self.start is None:
# this case represents `Content-Range: bytes -5`
self.start = self.total - self.end
self.end = self.total - 1
if self.start >= self.end:
raise RangeNotSatisfiable(
"Invalid for Content Range parameters", self
)
self.size = self.end - self.start + 1
self.headers = {
"Content-Range": "bytes %s-%s/%s"
% (self.start, self.end, self.total)
}
def __bool__(self):
return self.size > 0