import asyncio
import io
import os
import pathlib
import sys
from contextlib import suppress
from enum import Enum, auto
from mimetypes import MimeTypes
from stat import S_ISREG
from types import MappingProxyType
from typing import ( # noqa
IO,
TYPE_CHECKING,
Any,
Awaitable,
Callable,
Final,
Iterator,
List,
Optional,
Set,
Tuple,
Union,
cast,
)
from . import hdrs
from .abc import AbstractStreamWriter
from .helpers import ETAG_ANY, ETag, must_be_empty_body
from .typedefs import LooseHeaders, PathLike
from .web_exceptions import (
HTTPForbidden,
HTTPNotFound,
HTTPNotModified,
HTTPPartialContent,
HTTPPreconditionFailed,
HTTPRequestRangeNotSatisfiable,
)
from .web_response import StreamResponse
__all__ = ("FileResponse",)
if TYPE_CHECKING:
from .web_request import BaseRequest
_T_OnChunkSent = Optional[Callable[[bytes], Awaitable[None]]]
NOSENDFILE: Final[bool] = bool(os.environ.get("AIOHTTP_NOSENDFILE"))
CONTENT_TYPES: Final[MimeTypes] = MimeTypes()
# File extension to IANA encodings map that will be checked in the order defined.
ENCODING_EXTENSIONS = MappingProxyType(
{ext: CONTENT_TYPES.encodings_map[ext] for ext in (".br", ".gz")}
)
FALLBACK_CONTENT_TYPE = "application/octet-stream"
# Provide additional MIME type/extension pairs to be recognized.
# https://en.wikipedia.org/wiki/List_of_archive_formats#Compression_only
ADDITIONAL_CONTENT_TYPES = MappingProxyType(
{
"application/gzip": ".gz",
"application/x-brotli": ".br",
"application/x-bzip2": ".bz2",
"application/x-compress": ".Z",
"application/x-xz": ".xz",
}
)
class _FileResponseResult(Enum):
"""The result of the file response."""
SEND_FILE = auto() # Ie a regular file to send
NOT_ACCEPTABLE = auto() # Ie a socket, or non-regular file
PRE_CONDITION_FAILED = auto() # Ie If-Match or If-None-Match failed
NOT_MODIFIED = auto() # 304 Not Modified
# Add custom pairs and clear the encodings map so guess_type ignores them.
CONTENT_TYPES.encodings_map.clear()
for content_type, extension in ADDITIONAL_CONTENT_TYPES.items():
CONTENT_TYPES.add_type(content_type, extension) # type: ignore[attr-defined]
_CLOSE_FUTURES: Set[asyncio.Future[None]] = set()
class FileResponse(StreamResponse):
"""A response object can be used to send files."""
def __init__(
self,
path: PathLike,
chunk_size: int = 256 * 1024,
status: int = 200,
reason: Optional[str] = None,
headers: Optional[LooseHeaders] = None,
) -> None:
super().__init__(status=status, reason=reason, headers=headers)
self._path = pathlib.Path(path)
self._chunk_size = chunk_size
def _seek_and_read(self, fobj: IO[Any], offset: int, chunk_size: int) -> bytes:
fobj.seek(offset)
return fobj.read(chunk_size) # type: ignore[no-any-return]
async def _sendfile_fallback(
self, writer: AbstractStreamWriter, fobj: IO[Any], offset: int, count: int
) -> AbstractStreamWriter:
# To keep memory usage low,fobj is transferred in chunks
# controlled by the constructor's chunk_size argument.
chunk_size = self._chunk_size
loop = asyncio.get_event_loop()
chunk = await loop.run_in_executor(
None, self._seek_and_read, fobj, offset, chunk_size
)
while chunk:
await writer.write(chunk)
count = count - chunk_size
if count <= 0:
break
chunk = await loop.run_in_executor(None, fobj.read, min(chunk_size, count))
await writer.drain()
return writer
async def _sendfile(
self, request: "BaseRequest", fobj: IO[Any], offset: int, count: int
) -> AbstractStreamWriter:
writer = await super().prepare(request)
assert writer is not None
if NOSENDFILE or self.compression:
return await self._sendfile_fallback(writer, fobj, offset, count)
loop = request._loop
transport = request.transport
assert transport is not None
try:
await loop.sendfile(transport, fobj, offset, count)
except NotImplementedError:
return await self._sendfile_fallback(writer, fobj, offset, count)
await super().write_eof()
return writer
@staticmethod
def _etag_match(etag_value: str, etags: Tuple[ETag, ...], *, weak: bool) -> bool:
if len(etags) == 1 and etags[0].value == ETAG_ANY:
return True
return any(
etag.value == etag_value for etag in etags if weak or not etag.is_weak
)
async def _not_modified(
self, request: "BaseRequest", etag_value: str, last_modified: float
) -> Optional[AbstractStreamWriter]:
self.set_status(HTTPNotModified.status_code)
self._length_check = False
self.etag = etag_value # type: ignore[assignment]
self.last_modified = last_modified # type: ignore[assignment]
# Delete any Content-Length headers provided by user. HTTP 304
# should always have empty response body
return await super().prepare(request)
async def _precondition_failed(
self, request: "BaseRequest"
) -> Optional[AbstractStreamWriter]:
self.set_status(HTTPPreconditionFailed.status_code)
self.content_length = 0
return await super().prepare(request)
def _make_response(
self, request: "BaseRequest", accept_encoding: str
) -> Tuple[
_FileResponseResult, Optional[io.BufferedReader], os.stat_result, Optional[str]
]:
"""Return the response result, io object, stat result, and encoding.
If an uncompressed file is returned, the encoding is set to
:py:data:`None`.
This method should be called from a thread executor
since it calls os.stat which may block.
"""
file_path, st, file_encoding = self._get_file_path_stat_encoding(
accept_encoding
)
if not file_path:
return _FileResponseResult.NOT_ACCEPTABLE, None, st, None
etag_value = f"{st.st_mtime_ns:x}-{st.st_size:x}"
# https://www.rfc-editor.org/rfc/rfc9110#section-13.1.1-2
if (ifmatch := request.if_match) is not None and not self._etag_match(
etag_value, ifmatch, weak=False
):
return _FileResponseResult.PRE_CONDITION_FAILED, None, st, file_encoding
if (
(unmodsince := request.if_unmodified_since) is not None
and ifmatch is None
and st.st_mtime > unmodsince.timestamp()
):
return _FileResponseResult.PRE_CONDITION_FAILED, None, st, file_encoding
# https://www.rfc-editor.org/rfc/rfc9110#section-13.1.2-2
if (ifnonematch := request.if_none_match) is not None and self._etag_match(
etag_value, ifnonematch, weak=True
):
return _FileResponseResult.NOT_MODIFIED, None, st, file_encoding
if (
(modsince := request.if_modified_since) is not None
and ifnonematch is None
and st.st_mtime <= modsince.timestamp()
):
return _FileResponseResult.NOT_MODIFIED, None, st, file_encoding
fobj = file_path.open("rb")
with suppress(OSError):
# fstat() may not be available on all platforms
# Once we open the file, we want the fstat() to ensure
# the file has not changed between the first stat()
# and the open().
st = os.stat(fobj.fileno())
return _FileResponseResult.SEND_FILE, fobj, st, file_encoding
def _get_file_path_stat_encoding(
self, accept_encoding: str
) -> Tuple[Optional[pathlib.Path], os.stat_result, Optional[str]]:
file_path = self._path
for file_extension, file_encoding in ENCODING_EXTENSIONS.items():
if file_encoding not in accept_encoding:
continue
compressed_path = file_path.with_suffix(file_path.suffix + file_extension)
with suppress(OSError):
# Do not follow symlinks and ignore any non-regular files.
st = compressed_path.lstat()
if S_ISREG(st.st_mode):
return compressed_path, st, file_encoding
# Fallback to the uncompressed file
st = file_path.stat()
return file_path if S_ISREG(st.st_mode) else None, st, None
async def prepare(self, request: "BaseRequest") -> Optional[AbstractStreamWriter]:
loop = asyncio.get_running_loop()
# Encoding comparisons should be case-insensitive
# https://www.rfc-editor.org/rfc/rfc9110#section-8.4.1
accept_encoding = request.headers.get(hdrs.ACCEPT_ENCODING, "").lower()
try:
response_result, fobj, st, file_encoding = await loop.run_in_executor(
None, self._make_response, request, accept_encoding
)
except PermissionError:
self.set_status(HTTPForbidden.status_code)
return await super().prepare(request)
except OSError:
# Most likely to be FileNotFoundError or OSError for circular
# symlinks in python >= 3.13, so respond with 404.
self.set_status(HTTPNotFound.status_code)
return await super().prepare(request)
# Forbid special files like sockets, pipes, devices, etc.
if response_result is _FileResponseResult.NOT_ACCEPTABLE:
self.set_status(HTTPForbidden.status_code)
return await super().prepare(request)
if response_result is _FileResponseResult.PRE_CONDITION_FAILED:
return await self._precondition_failed(request)
if response_result is _FileResponseResult.NOT_MODIFIED:
etag_value = f"{st.st_mtime_ns:x}-{st.st_size:x}"
last_modified = st.st_mtime
return await self._not_modified(request, etag_value, last_modified)
assert fobj is not None
try:
return await self._prepare_open_file(request, fobj, st, file_encoding)
finally:
# We do not await here because we do not want to wait
# for the executor to finish before returning the response
# so the connection can begin servicing another request
# as soon as possible.
close_future = loop.run_in_executor(None, fobj.close)
# Hold a strong reference to the future to prevent it from being
# garbage collected before it completes.
_CLOSE_FUTURES.add(close_future)
close_future.add_done_callback(_CLOSE_FUTURES.remove)
async def _prepare_open_file(
self,
request: "BaseRequest",
fobj: io.BufferedReader,
st: os.stat_result,
file_encoding: Optional[str],
) -> Optional[AbstractStreamWriter]:
status = self._status
file_size: int = st.st_size
file_mtime: float = st.st_mtime
count: int = file_size
start: Optional[int] = None
if (ifrange := request.if_range) is None or file_mtime <= ifrange.timestamp():
# If-Range header check:
# condition = cached date >= last modification date
# return 206 if True else 200.
# if False:
# Range header would not be processed, return 200
# if True but Range header missing
# return 200
try:
rng = request.http_range
start = rng.start
end: Optional[int] = rng.stop
except ValueError:
# https://tools.ietf.org/html/rfc7233:
# A server generating a 416 (Range Not Satisfiable) response to
# a byte-range request SHOULD send a Content-Range header field
# with an unsatisfied-range value.
# The complete-length in a 416 response indicates the current
# length of the selected representation.
#
# Will do the same below. Many servers ignore this and do not
# send a Content-Range header with HTTP 416
self._headers[hdrs.CONTENT_RANGE] = f"bytes */{file_size}"
self.set_status(HTTPRequestRangeNotSatisfiable.status_code)
return await super().prepare(request)
# If a range request has been made, convert start, end slice
# notation into file pointer offset and count
if start is not None:
if start < 0 and end is None: # return tail of file
start += file_size
if start < 0:
# if Range:bytes=-1000 in request header but file size
# is only 200, there would be trouble without this
start = 0
count = file_size - start
else:
# rfc7233:If the last-byte-pos value is
# absent, or if the value is greater than or equal to
# the current length of the representation data,
# the byte range is interpreted as the remainder
# of the representation (i.e., the server replaces the
# value of last-byte-pos with a value that is one less than
# the current length of the selected representation).
count = (
min(end if end is not None else file_size, file_size) - start
)
if start >= file_size:
# HTTP 416 should be returned in this case.
#
# According to https://tools.ietf.org/html/rfc7233:
# If a valid byte-range-set includes at least one
# byte-range-spec with a first-byte-pos that is less than
# the current length of the representation, or at least one
# suffix-byte-range-spec with a non-zero suffix-length,
# then the byte-range-set is satisfiable. Otherwise, the
# byte-range-set is unsatisfiable.
self._headers[hdrs.CONTENT_RANGE] = f"bytes */{file_size}"
self.set_status(HTTPRequestRangeNotSatisfiable.status_code)
return await super().prepare(request)
status = HTTPPartialContent.status_code
# Even though you are sending the whole file, you should still
# return a HTTP 206 for a Range request.
self.set_status(status)
# If the Content-Type header is not already set, guess it based on the
# extension of the request path. The encoding returned by guess_type
# can be ignored since the map was cleared above.
if hdrs.CONTENT_TYPE not in self._headers:
if sys.version_info >= (3, 13):
guesser = CONTENT_TYPES.guess_file_type
else:
guesser = CONTENT_TYPES.guess_type
self.content_type = guesser(self._path)[0] or FALLBACK_CONTENT_TYPE
if file_encoding:
self._headers[hdrs.CONTENT_ENCODING] = file_encoding
self._headers[hdrs.VARY] = hdrs.ACCEPT_ENCODING
# Disable compression if we are already sending
# a compressed file since we don't want to double
# compress.
self._compression = False
self.etag = f"{st.st_mtime_ns:x}-{st.st_size:x}" # type: ignore[assignment]
self.last_modified = file_mtime # type: ignore[assignment]
self.content_length = count
self._headers[hdrs.ACCEPT_RANGES] = "bytes"
if status == HTTPPartialContent.status_code:
real_start = start
assert real_start is not None
self._headers[hdrs.CONTENT_RANGE] = "bytes {}-{}/{}".format(
real_start, real_start + count - 1, file_size
)
# If we are sending 0 bytes calling sendfile() will throw a ValueError
if count == 0 or must_be_empty_body(request.method, status):
return await super().prepare(request)
# be aware that start could be None or int=0 here.
offset = start or 0
return await self._sendfile(request, fobj, offset, count)
