periodic snapshots

kvmd/apps/kvmd/snapshoter.py

@@ -0,0 +1,130 @@
+# ========================================================================== #
+#                                                                            #
+#    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 asyncio
+import time
+
+from typing import Callable
+
+from ...logging import get_logger
+
+from ...plugins.hid import BaseHid
+
+from ... import aiotools
+
+from .streamer import Streamer
+
+
+# =====
+class Snapshoter:  # pylint: disable=too-many-instance-attributes
+    def __init__(
+        self,
+        hid: BaseHid,
+        streamer: Streamer,
+
+        idle_interval: float,
+        live_interval: float,
+
+        wakeup_key: str,
+        wakeup_move: int,
+
+        online_delay: float,
+        retries: int,
+        retries_delay: float,
+    ) -> None:
+
+        self.__hid = hid
+        self.__streamer = streamer
+
+        if idle_interval or live_interval:
+            self.__idle_interval = (idle_interval or live_interval)
+            self.__live_interval = (live_interval or idle_interval)
+            assert self.__idle_interval
+            assert self.__live_interval
+        else:
+            self.__idle_interval = self.__live_interval = 0.0
+
+        self.__wakeup_key = wakeup_key
+        self.__wakeup_move = wakeup_move
+
+        self.__online_delay = online_delay
+        self.__retries = retries
+        self.__retries_delay = retries_delay
+
+        self.__snapshoting = False
+
+    async def run(self, is_live: Callable[[], bool], notifier: aiotools.AioNotifier) -> None:
+        if self.__idle_interval or self.__live_interval:
+            get_logger(0).info("Running periodic stream snapshot: idle=%.2f; live=%.2f ...",
+                               self.__idle_interval, self.__live_interval)
+
+            last_snapshot_ts = 0.0
+            while True:
+                live = is_live()
+                if last_snapshot_ts + (self.__live_interval if live else self.__idle_interval) < time.time():
+                    await self.__make_snapshot(live, notifier)
+                    last_snapshot_ts = time.time()
+                await asyncio.sleep(min(self.__idle_interval, self.__live_interval))
+        else:
+            await aiotools.wait_infinite()
+
+    def snapshoting(self) -> bool:
+        return self.__snapshoting
+
+    async def __make_snapshot(self, live: bool, notifier: aiotools.AioNotifier) -> None:
+        logger = get_logger(0)
+        logger.info("Time to make the new snapshot (%s)", ("live" if live else "idle"))
+        try:
+            self.__snapshoting = True
+            await notifier.notify()
+
+            if not live:
+                if self.__wakeup_key:
+                    logger.info("Waking up using key %r ...", self.__wakeup_key)
+                    self.__hid.send_key_events([
+                        (self.__wakeup_key, True),
+                        (self.__wakeup_key, False),
+                    ])
+                if self.__wakeup_move:
+                    logger.info("Waking up using mouse move for %d units ...", self.__wakeup_move)
+                    self.__hid.send_mouse_move_event(0, 0)
+                    self.__hid.send_mouse_move_event(self.__wakeup_move, self.__wakeup_move)
+
+                if self.__online_delay:
+                    logger.info("Waiting %.2f seconds for online ...", self.__online_delay)
+                    await asyncio.sleep(self.__online_delay)
+
+            retries = self.__retries
+            while retries:
+                snapshot = await self.__streamer.make_snapshot(save=True, load=False, allow_offline=False)
+                if snapshot:
+                    logger.info("New snapshot saved: %dx%d", snapshot.width, snapshot.height)
+                    break
+                retries -= 1
+                await asyncio.sleep(self.__retries_delay)
+            else:
+                logger.error("Can't make snapshot after %d retries", self.__retries)
+        except Exception:  # Этого вообще-то не должно случаться, апи внутри заэксцепчены, но мало ли
+            logger.exception("Unhandled exception while making snapshot")
+        finally:
+            self.__snapshoting = False
+            await notifier.notify()