new snapshot api

kvmd/apps/kvmd/api/streamer.py

@@ -0,0 +1,110 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main Pi-KVM daemon.                                          #
+#                                                                            #
+#    Copyright (C) 2018  Maxim Devaev <mdevaev@gmail.com>                    #
+#                                                                            #
+#    This program is free software: you can redistribute it and/or modify    #
+#    it under the terms of the GNU General Public License as published by    #
+#    the Free Software Foundation, either version 3 of the License, or       #
+#    (at your option) any later version.                                     #
+#                                                                            #
+#    This program is distributed in the hope that it will be useful,         #
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
+#    GNU General Public License for more details.                            #
+#                                                                            #
+#    You should have received a copy of the GNU General Public License       #
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+# ========================================================================== #
+
+
+import io
+import functools
+
+from aiohttp.web import Request
+from aiohttp.web import Response
+
+from PIL import Image
+
+from ....validators.basic import valid_bool
+from ....validators.basic import valid_int_f0
+
+from ....validators.kvm import valid_stream_quality
+
+from .... import aiotools
+
+from ..http import UnavailableError
+from ..http import exposed_http
+from ..http import make_json_response
+
+from ..streamer import StreamerSnapshot
+from ..streamer import Streamer
+
+
+# =====
+class StreamerApi:
+    def __init__(self, streamer: Streamer) -> None:
+        self.__streamer = streamer
+
+    # =====
+
+    @exposed_http("GET", "/streamer")
+    async def __state_handler(self, _: Request) -> Response:
+        return make_json_response(await self.__streamer.get_state())
+
+    @exposed_http("GET", "/streamer/snapshot")
+    async def __make_snapshot_handler(self, request: Request) -> Response:
+        if (snapshot := await self.__streamer.make_snapshot(
+            save=valid_bool(request.query.get("save", "false")),
+            load=valid_bool(request.query.get("load", "false")),
+            allow_offline=valid_bool(request.query.get("allow_offline", "false")),
+        )):
+            if valid_bool(request.query.get("preview", "false")):
+                data = await self.__make_preview(
+                    snapshot=snapshot,
+                    max_width=valid_int_f0(request.query.get("preview_max_width", "0")),
+                    max_height=valid_int_f0(request.query.get("preview_max_height", "0")),
+                    quality=valid_stream_quality(request.query.get("preview_quality", "80")),
+                )
+            else:
+                data = snapshot.data
+            return Response(
+                body=data,
+                headers=dict(snapshot.headers),
+                content_type="image/jpeg",
+            )
+        raise UnavailableError()
+
+    @exposed_http("DELETE", "/streamer/snapshot")
+    async def __remove_snapshot_handler(self, _: Request) -> Response:
+        self.__streamer.remove_snapshot()
+        return make_json_response()
+
+    # =====
+
+    async def __make_preview(self, snapshot: StreamerSnapshot, max_width: int, max_height: int, quality: int) -> bytes:
+        if max_width == 0 and max_height == 0:
+            max_width = snapshot.width // 5
+            max_height = snapshot.height // 5
+        else:
+            max_width = min((max_width or snapshot.width), snapshot.width)
+            max_height = min((max_height or snapshot.height), snapshot.height)
+
+        if max_width == snapshot.width and max_height == snapshot.height:
+            return snapshot.data
+        else:
+            return (await aiotools.run_async(self.__inner_make_preview, snapshot, max_width, max_height, quality))
+
+    @functools.lru_cache(maxsize=1)
+    def __inner_make_preview(self, snapshot: StreamerSnapshot, max_width: int, max_height: int, quality: int) -> bytes:
+        assert 0 < max_width <= snapshot.width
+        assert 0 < max_height <= snapshot.height
+        assert not (max_width == snapshot.width and max_height == snapshot.height)
+        with io.BytesIO(snapshot.data) as snapshot_bio:
+            with io.BytesIO() as preview_bio:
+                with Image.open(snapshot_bio) as image:
+                    image.thumbnail((max_width, max_height), Image.ANTIALIAS)
+                    image.save(preview_bio, format="jpeg", quality=quality)
+                    return preview_bio.getvalue()

kvmd/apps/kvmd/http.py

@@ -39,6 +39,11 @@ class ForbiddenError(HttpError):
         super().__init__("Forbidden", 403)
 
 
+class UnavailableError(HttpError):
+    def __init__(self) -> None:
+        super().__init__("Service Unavailable", 503)
+
+
 # =====
 @dataclasses.dataclass(frozen=True)
 class HttpExposed:

kvmd/apps/kvmd/server.py

@@ -83,6 +83,7 @@ from .api.wol import WolApi
 from .api.hid import HidApi
 from .api.atx import AtxApi
 from .api.msd import MsdApi
+from .api.streamer import StreamerApi
 
 
 # =====
@@ -133,6 +134,7 @@ class KvmdServer(HttpServer):  # pylint: disable=too-many-arguments,too-many-ins
             HidApi(hid, keymap_path),
             AtxApi(atx),
             MsdApi(msd, sync_chunk_size),
+            StreamerApi(streamer),
         ]
 
         self.__ws_handlers: Dict[str, Callable] = {}
@@ -164,11 +166,7 @@ class KvmdServer(HttpServer):  # pylint: disable=too-many-arguments,too-many-ins
     async def __info_handler(self, _: aiohttp.web.Request) -> aiohttp.web.Response:
         return make_json_response(await self.__make_info())
 
-    # ===== STREAMER
-
-    @exposed_http("GET", "/streamer")
-    async def __streamer_state_handler(self, _: aiohttp.web.Request) -> aiohttp.web.Response:
-        return make_json_response(await self.__streamer.get_state())
+    # ===== STREAMER CONTROLLER
 
     @exposed_http("POST", "/streamer/set_params")
     async def __streamer_set_params_handler(self, request: aiohttp.web.Request) -> aiohttp.web.Response:

kvmd/apps/kvmd/streamer.py

@@ -24,7 +24,10 @@ import os
 import signal
 import asyncio
 import asyncio.subprocess
+import dataclasses
+import operator
 
+from typing import Tuple
 from typing import List
 from typing import Dict
 from typing import AsyncGenerator
@@ -42,6 +45,16 @@ from ... import gpio
 
 
 # =====
+@dataclasses.dataclass(frozen=True)
+class StreamerSnapshot:
+    online: bool
+    width: int
+    height: int
+    mtime: float
+    headers: Tuple[Tuple[str, str], ...]
+    data: bytes
+
+
 class Streamer:  # pylint: disable=too-many-instance-attributes
     def __init__(  # pylint: disable=too-many-arguments,too-many-locals
         self,
@@ -101,6 +114,10 @@ class Streamer:  # pylint: disable=too-many-instance-attributes
 
         self.__http_session: Optional[aiohttp.ClientSession] = None
 
+        self.__snapshot: Optional[StreamerSnapshot] = None
+
+        self.__state_notifier = aiotools.AioNotifier()
+
     # =====
 
     @aiotools.atomic
@@ -163,6 +180,8 @@ class Streamer:  # pylint: disable=too-many-instance-attributes
         # Запущено и не планирует останавливаться
         return bool(self.__streamer_task and not self.__stop_task)
 
+    # =====
+
     def set_params(self, params: Dict) -> None:
         assert not self.__streamer_task
         self.__params = {
@@ -176,6 +195,8 @@ class Streamer:  # pylint: disable=too-many-instance-attributes
     def get_params(self) -> Dict:
         return dict(self.__params)
 
+    # =====
+
     async def get_state(self) -> Dict:
         state = None
         if self.__streamer_task:
@@ -188,18 +209,24 @@ class Streamer:  # pylint: disable=too-many-instance-attributes
                 pass
             except Exception:
                 get_logger().exception("Invalid streamer response from /state")
+
+        snapshot: Optional[Dict] = None
+        if self.__snapshot:
+            snapshot = dataclasses.asdict(self.__snapshot)
+            del snapshot["headers"]
+            del snapshot["data"]
+
         return {
             "limits": {"max_fps": self.__max_fps},
             "params": self.__params,
+            "snapshot": {"saved": snapshot},
             "state": state,
         }
 
     async def poll_state(self) -> AsyncGenerator[Dict, None]:
-        notifier = aiotools.AioNotifier()
-
         def signal_handler(*_: Any) -> None:
             get_logger(0).info("Got SIGUSR2, checking the stream state ...")
-            asyncio.ensure_future(notifier.notify())
+            asyncio.ensure_future(self.__state_notifier.notify())
 
         get_logger(0).info("Installing SIGUSR2 streamer handler ...")
         asyncio.get_event_loop().add_signal_handler(signal.SIGUSR2, signal_handler)
@@ -213,10 +240,12 @@ class Streamer:  # pylint: disable=too-many-instance-attributes
                 prev_state = state
 
             if waiter_task is None:
-                waiter_task = asyncio.create_task(notifier.wait())
+                waiter_task = asyncio.create_task(self.__state_notifier.wait())
             if waiter_task in (await aiotools.wait_first(asyncio.sleep(self.__state_poll), waiter_task))[0]:
                 waiter_task = None
 
+    # =====
+
     async def get_info(self) -> Dict:
         version = (await aioproc.read_process([self.__cmd[0], "--version"], err_to_null=True))[1]
         return {
@@ -224,6 +253,49 @@ class Streamer:  # pylint: disable=too-many-instance-attributes
             "version": version,
         }
 
+    async def make_snapshot(self, save: bool, load: bool, allow_offline: bool) -> Optional[StreamerSnapshot]:
+        if load:
+            return self.__snapshot
+        else:
+            session = self.__ensure_http_session()
+            try:
+                async with session.get(self.__make_url("snapshot")) as response:
+                    htclient.raise_not_200(response)
+                    online = (response.headers["X-UStreamer-Online"] == "true")
+                    if online or allow_offline:
+                        snapshot = StreamerSnapshot(
+                            online=online,
+                            width=int(response.headers["X-UStreamer-Width"]),
+                            height=int(response.headers["X-UStreamer-Height"]),
+                            mtime=float(response.headers["X-Timestamp"]),
+                            headers=tuple(
+                                (key, value)
+                                for (key, value) in sorted(response.headers.items(), key=operator.itemgetter(0))
+                                if key.lower().startswith("x-ustreamer-") or key.lower() in [
+                                    "x-timestamp",
+                                    "access-control-allow-origin",
+                                    "cache-control",
+                                    "pragma",
+                                    "expires",
+                                ]
+                            ),
+                            data=bytes(await response.read()),
+                        )
+                        if save:
+                            self.__snapshot = snapshot
+                            await self.__state_notifier.notify()
+                        return snapshot
+            except (aiohttp.ClientConnectionError, aiohttp.ServerConnectionError):
+                pass
+            except Exception:
+                get_logger().exception("Invalid streamer response from /snapshot")
+            return None
+
+    def remove_snapshot(self) -> None:
+        self.__snapshot = None
+
+    # =====
+
     @aiotools.atomic
     async def cleanup(self) -> None:
         try:

kvmd/clients/streamer.py

@@ -54,7 +54,7 @@ class StreamerClient:
 
     async def read_stream(self) -> AsyncGenerator[Tuple[bool, int, int, bytes], None]:
         try:
-            async with self.__make_http_session(infinite=True) as session:
+            async with self.__make_http_session() as session:
                 async with session.get(
                     url=self.__make_url("stream"),
                     params={"extra_headers": "1"},
@@ -84,24 +84,14 @@ class StreamerClient:
             raise StreamerError(f"{type(err).__name__}: {err}")
         raise StreamerError("Reached EOF")
 
-#    async def get_snapshot(self) -> Tuple[bool, bytes]:
-#        async with self.__make_http_session(infinite=False) as session:
-#            async with session.get(self.__make_url("snapshot")) as response:
-#                htclient.raise_not_200(response)
-#                return (
-#                    (response.headers["X-UStreamer-Online"] == "true"),
-#                    bytes(await response.read()),
-#                )
-
-    def __make_http_session(self, infinite: bool) -> aiohttp.ClientSession:
-        kwargs: Dict = {"headers": {"User-Agent": self.__user_agent}}
-        if infinite:
-            kwargs["timeout"] = aiohttp.ClientTimeout(
+    def __make_http_session(self) -> aiohttp.ClientSession:
+        kwargs: Dict = {
+            "headers": {"User-Agent": self.__user_agent},
+            "timeout": aiohttp.ClientTimeout(
                 connect=self.__timeout,
                 sock_read=self.__timeout,
-            )
-        else:
-            kwargs["timeout"] = aiohttp.ClientTimeout(total=self.__timeout)
+            ),
+        }
         if self.__unix_path:
             kwargs["connector"] = aiohttp.UnixConnector(path=self.__unix_path)
         return aiohttp.ClientSession(**kwargs)

web/share/js/kvm/stream.js

@@ -193,7 +193,7 @@ export function Streamer() {
 
 	var __clickScreenshotButton = function() {
 		let el_a = document.createElement("a");
-		el_a.href = "/streamer/snapshot";
+		el_a.href = "/api/streamer/snapshot?allow_offline=1";
 		el_a.target = "_blank";
 		document.body.appendChild(el_a);
 		el_a.click();