commit something

starlette/responses.py

@@ -319,6 +319,7 @@ def set_stat_headers(self, stat_result: os.stat_result) -> None:
         self.headers.setdefault("etag", etag)
 
     async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
+        send_header_only: bool = scope["method"].upper() == "HEAD"
         if self.stat_result is None:
             try:
                 stat_result = await anyio.to_thread.run_sync(os.stat, self.path)
@@ -336,17 +337,33 @@ async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
         http_range = headers.get("range")
         # http_if_range = headers.get("if-range")
 
-        ranges = self._parse_range_header(http_range, stat_result.st_size)
-        print(ranges)
+        if http_range is None:
+            await self._handle_simple(send, send_header_only)
+        else:
+            ranges = self._parse_range_header(http_range, stat_result.st_size)
+
+            if len(ranges) == 1:
+                start, end = ranges[0]
+                await self._handle_single_range(
+                    send, start, end, stat_result.st_size, send_header_only
+                )
+            else:
+                await self._handle_multiple_ranges(
+                    send, ranges, stat_result.st_size, send_header_only
+                )
 
+        if self.background is not None:
+            await self.background()
+
+    async def _handle_simple(self, send: Send, send_header_only: bool) -> None:
         await send(
             {
                 "type": "http.response.start",
                 "status": self.status_code,
                 "headers": self.raw_headers,
             }
         )
-        if scope["method"].upper() == "HEAD":
+        if send_header_only:
             await send({"type": "http.response.body", "body": b"", "more_body": False})
         else:
             async with await anyio.open_file(self.path, mode="rb") as file:
@@ -361,8 +378,103 @@ async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
                             "more_body": more_body,
                         }
                     )
-        if self.background is not None:
-            await self.background()
+
+    async def _handle_single_range(
+        self, send: Send, start: int, end: int, file_size: int, send_header_only: bool
+    ) -> None:
+        self.headers["content-range"] = f"bytes {start}-{end - 1}/{file_size}"
+        await send(
+            {
+                "type": "http.response.start",
+                "status": 206,
+                "headers": self.raw_headers,
+            }
+        )
+        if send_header_only:
+            await send({"type": "http.response.body", "body": b"", "more_body": False})
+        else:
+            async with await anyio.open_file(self.path, mode="rb") as file:
+                await file.seek(start)
+                more_body = True
+                while more_body:
+                    chunk = await file.read(min(self.chunk_size, end - start))
+                    start += len(chunk)
+                    more_body = len(chunk) == self.chunk_size and start < end
+                    await send(
+                        {
+                            "type": "http.response.body",
+                            "body": chunk,
+                            "more_body": more_body,
+                        }
+                    )
+
+    async def _handle_multiple_ranges(
+        self,
+        send: Send,
+        ranges: typing.List[typing.Tuple[int, int]],
+        file_size: int,
+        send_header_only: bool,
+    ) -> None:
+        boundary = md5_hexdigest(os.urandom(16), usedforsecurity=False)
+        content_type = f"multipart/byteranges; boundary={boundary}"
+        self.headers["content-type"] = content_type
+        await send(
+            {
+                "type": "http.response.start",
+                "status": 206,
+                "headers": self.raw_headers,
+            }
+        )
+        if send_header_only:
+            await send({"type": "http.response.body", "body": b"", "more_body": False})
+        else:
+            async with await anyio.open_file(self.path, mode="rb") as file:
+                for start, end in ranges:
+                    await send(
+                        {
+                            "type": "http.response.body",
+                            "body": b"\r\n--" + boundary.encode("ascii") + b"\r\n",
+                            "more_body": True,
+                        }
+                    )
+                    await send(
+                        {
+                            "type": "http.response.body",
+                            "body": f"Content-Type: {self.media_type}\r\n".encode(
+                                "utf-8"
+                            ),
+                            "more_body": True,
+                        }
+                    )
+                    await send(
+                        {
+                            "type": "http.response.body",
+                            "body": f"Content-Range: bytes {start}-{end - 1}/{file_size}\r\n\r\n".encode(
+                                "utf-8"
+                            ),
+                            "more_body": True,
+                        }
+                    )
+                    await file.seek(start)
+                    more_body = True
+                    while more_body:
+                        chunk = await file.read(min(self.chunk_size, end - start))
+                        start += len(chunk)
+                        more_body = len(chunk) == self.chunk_size and start < end
+                        await send(
+                            {
+                                "type": "http.response.body",
+                                "body": chunk,
+                                "more_body": more_body,
+                            }
+                        )
+                await send(
+                    {
+                        "type": "http.response.body",
+                        "body": b"\r\n--" + boundary.encode("ascii") + b"--\r\n",
+                        "more_body": False,
+                    }
+                )
 
     def _parse_range_header(
         self, http_range: typing.Optional[str], file_size: int