import mimetypes import os import pathlib from . import hdrs from .helpers import set_exception, set_result from .http_writer import StreamWriter from .log import server_logger from .web_exceptions import (HTTPNotModified, HTTPOk, HTTPPartialContent, HTTPPreconditionFailed, HTTPRequestRangeNotSatisfiable) from .web_response import StreamResponse __all__ = ('FileResponse',) NOSENDFILE = bool(os.environ.get("AIOHTTP_NOSENDFILE")) class SendfileStreamWriter(StreamWriter): def __init__(self, *args, **kwargs): self._sendfile_buffer = [] super().__init__(*args, **kwargs) def _write(self, chunk): # we overwrite StreamWriter._write, so nothing can be appended to # _buffer, and nothing is written to the transport directly by the # parent class self.output_size += len(chunk) self._sendfile_buffer.append(chunk) def _sendfile_cb(self, fut, out_fd, in_fd, offset, count, loop, registered): if registered: loop.remove_writer(out_fd) if fut.cancelled(): return try: n = os.sendfile(out_fd, in_fd, offset, count) if n == 0: # EOF reached n = count except (BlockingIOError, InterruptedError): n = 0 except Exception as exc: set_exception(fut, exc) return if n < count: loop.add_writer(out_fd, self._sendfile_cb, fut, out_fd, in_fd, offset + n, count - n, loop, True) else: set_result(fut, None) async def sendfile(self, fobj, count): out_socket = self.transport.get_extra_info('socket').dup() out_socket.setblocking(False) out_fd = out_socket.fileno() in_fd = fobj.fileno() offset = fobj.tell() loop = self.loop data = b''.join(self._sendfile_buffer) try: await loop.sock_sendall(out_socket, data) fut = loop.create_future() self._sendfile_cb(fut, out_fd, in_fd, offset, count, loop, False) await fut except Exception: server_logger.debug('Socket error') self.transport.close() finally: out_socket.close() self.output_size += count await super().write_eof() async def write_eof(self, chunk=b''): pass class FileResponse(StreamResponse): """A response object can be used to send files.""" def __init__(self, path, chunk_size=256*1024, *args, **kwargs): super().__init__(*args, **kwargs) if isinstance(path, str): path = pathlib.Path(path) self._path = path self._chunk_size = chunk_size async def _sendfile_system(self, request, fobj, count): # Write count bytes of fobj to resp using # the os.sendfile system call. # # For details check # https://github.com/KeepSafe/aiohttp/issues/1177 # See https://github.com/KeepSafe/aiohttp/issues/958 for details # # request should be a aiohttp.web.Request instance. # fobj should be an open file object. # count should be an integer > 0. transport = request.transport if (transport.get_extra_info("sslcontext") or transport.get_extra_info("socket") is None or self.compression): writer = await self._sendfile_fallback(request, fobj, count) else: writer = SendfileStreamWriter( request.protocol, request.loop ) request._payload_writer = writer await super().prepare(request) await writer.sendfile(fobj, count) return writer async def _sendfile_fallback(self, request, fobj, count): # Mimic the _sendfile_system() method, but without using the # os.sendfile() system call. This should be used on systems # that don't support the os.sendfile(). # To avoid blocking the event loop & to keep memory usage low, # fobj is transferred in chunks controlled by the # constructor's chunk_size argument. writer = await super().prepare(request) chunk_size = self._chunk_size chunk = fobj.read(chunk_size) while True: await writer.write(chunk) count = count - chunk_size if count <= 0: break chunk = fobj.read(min(chunk_size, count)) await writer.drain() return writer if hasattr(os, "sendfile") and not NOSENDFILE: # pragma: no cover _sendfile = _sendfile_system else: # pragma: no cover _sendfile = _sendfile_fallback async def prepare(self, request): filepath = self._path gzip = False if 'gzip' in request.headers.get(hdrs.ACCEPT_ENCODING, ''): gzip_path = filepath.with_name(filepath.name + '.gz') if gzip_path.is_file(): filepath = gzip_path gzip = True st = filepath.stat() modsince = request.if_modified_since if modsince is not None and st.st_mtime <= modsince.timestamp(): self.set_status(HTTPNotModified.status_code) self._length_check = False # Delete any Content-Length headers provided by user. HTTP 304 # should always have empty response body return await super().prepare(request) unmodsince = request.if_unmodified_since if unmodsince is not None and st.st_mtime > unmodsince.timestamp(): self.set_status(HTTPPreconditionFailed.status_code) return await super().prepare(request) if hdrs.CONTENT_TYPE not in self.headers: ct, encoding = mimetypes.guess_type(str(filepath)) if not ct: ct = 'application/octet-stream' should_set_ct = True else: encoding = 'gzip' if gzip else None should_set_ct = False status = HTTPOk.status_code file_size = st.st_size count = file_size start = None ifrange = request.if_range if ifrange is None or st.st_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 = 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] = 'bytes */{0}'.format( 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 or end 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] = 'bytes */{0}'.format( 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 should_set_ct: self.content_type = ct if encoding: self.headers[hdrs.CONTENT_ENCODING] = encoding if gzip: self.headers[hdrs.VARY] = hdrs.ACCEPT_ENCODING self.last_modified = st.st_mtime self.content_length = count self.headers[hdrs.ACCEPT_RANGES] = 'bytes' if status == HTTPPartialContent.status_code: self.headers[hdrs.CONTENT_RANGE] = 'bytes {0}-{1}/{2}'.format( start, start + count - 1, file_size) with filepath.open('rb') as fobj: if start: # be aware that start could be None or int=0 here. fobj.seek(start) return await self._sendfile(request, fobj, count)