initial commit

env/lib/python3.10/site-packages/jeepney/io/asyncio.py

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+import asyncio
+import contextlib
+from itertools import count
+from typing import Optional
+
+from jeepney.auth import Authenticator, BEGIN
+from jeepney.bus import get_bus
+from jeepney import Message, MessageType, Parser
+from jeepney.wrappers import ProxyBase, unwrap_msg
+from jeepney.bus_messages import message_bus
+from .common import (
+    MessageFilters, FilterHandle, ReplyMatcher, RouterClosed, check_replyable,
+)
+
+
+class DBusConnection:
+    """A plain D-Bus connection with no matching of replies.
+
+    This doesn't run any separate tasks: sending and receiving are done in
+    the task that calls those methods. It's suitable for implementing servers:
+    several worker tasks can receive requests and send replies.
+    For a typical client pattern, see :class:`DBusRouter`.
+    """
+    def __init__(self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter):
+        self.reader = reader
+        self.writer = writer
+        self.parser = Parser()
+        self.outgoing_serial = count(start=1)
+        self.unique_name = None
+        self.send_lock = asyncio.Lock()
+
+    async def send(self, message: Message, *, serial=None):
+        """Serialise and send a :class:`~.Message` object"""
+        async with self.send_lock:
+            if serial is None:
+                serial = next(self.outgoing_serial)
+            self.writer.write(message.serialise(serial))
+            await self.writer.drain()
+
+    async def receive(self) -> Message:
+        """Return the next available message from the connection"""
+        while True:
+            msg = self.parser.get_next_message()
+            if msg is not None:
+                return msg
+
+            b = await self.reader.read(4096)
+            if not b:
+                raise EOFError
+            self.parser.add_data(b)
+
+    async def close(self):
+        """Close the D-Bus connection"""
+        self.writer.close()
+        await self.writer.wait_closed()
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb):
+        await self.close()
+
+
+async def open_dbus_connection(bus='SESSION'):
+    """Open a plain D-Bus connection
+
+    :return: :class:`DBusConnection`
+    """
+    bus_addr = get_bus(bus)
+    reader, writer = await asyncio.open_unix_connection(bus_addr)
+
+    # Authentication flow
+    authr = Authenticator()
+    for req_data in authr:
+        writer.write(req_data)
+        await writer.drain()
+        b = await reader.read(1024)
+        if not b:
+            raise EOFError("Socket closed before authentication")
+        authr.feed(b)
+
+    writer.write(BEGIN)
+    await writer.drain()
+    # Authentication finished
+
+    conn = DBusConnection(reader, writer)
+
+    # Say *Hello* to the message bus - this must be the first message, and the
+    # reply gives us our unique name.
+    async with DBusRouter(conn) as router:
+        reply_body = await asyncio.wait_for(Proxy(message_bus, router).Hello(), 10)
+        conn.unique_name = reply_body[0]
+
+    return conn
+
+class DBusRouter:
+    """A 'client' D-Bus connection which can wait for a specific reply.
+
+    This runs a background receiver task, and makes it possible to send a
+    request and wait for the relevant reply.
+    """
+    _nursery_mgr = None
+    _send_cancel_scope = None
+    _rcv_cancel_scope = None
+
+    def __init__(self, conn: DBusConnection):
+        self._conn = conn
+        self._replies = ReplyMatcher()
+        self._filters = MessageFilters()
+        self._rcv_task = asyncio.create_task(self._receiver())
+
+    @property
+    def unique_name(self):
+        return self._conn.unique_name
+
+    async def send(self, message, *, serial=None):
+        """Send a message, don't wait for a reply"""
+        await self._conn.send(message, serial=serial)
+
+    async def send_and_get_reply(self, message) -> Message:
+        """Send a method call message and wait for the reply
+
+        Returns the reply message (method return or error message type).
+        """
+        check_replyable(message)
+        if self._rcv_task.done():
+            raise RouterClosed("This DBusRouter has stopped")
+
+        serial = next(self._conn.outgoing_serial)
+
+        with self._replies.catch(serial, asyncio.Future()) as reply_fut:
+            await self.send(message, serial=serial)
+            return (await reply_fut)
+
+    def filter(self, rule, *, queue: Optional[asyncio.Queue] =None, bufsize=1):
+        """Create a filter for incoming messages
+
+        Usage::
+
+            with router.filter(rule) as queue:
+                matching_msg = await queue.get()
+
+        :param MatchRule rule: Catch messages matching this rule
+        :param asyncio.Queue queue: Send matching messages here
+        :param int bufsize: If no queue is passed in, create one with this size
+        """
+        return FilterHandle(self._filters, rule, queue or asyncio.Queue(bufsize))
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb):
+        if self._rcv_task.done():
+            self._rcv_task.result()  # Throw exception if receive task failed
+        else:
+            self._rcv_task.cancel()
+            with contextlib.suppress(asyncio.CancelledError):
+                await self._rcv_task
+        return False
+
+    # Code to run in receiver task ------------------------------------
+
+    def _dispatch(self, msg: Message):
+        """Handle one received message"""
+        if self._replies.dispatch(msg):
+            return
+
+        for filter in list(self._filters.matches(msg)):
+            try:
+                filter.queue.put_nowait(msg)
+            except asyncio.QueueFull:
+                pass
+
+    async def _receiver(self):
+        """Receiver loop - runs in a separate task"""
+        try:
+            while True:
+                msg = await self._conn.receive()
+                self._dispatch(msg)
+        finally:
+            # Send errors to any tasks still waiting for a message.
+            self._replies.drop_all()
+
+class open_dbus_router:
+    """Open a D-Bus 'router' to send and receive messages
+
+    Use as an async context manager::
+
+        async with open_dbus_router() as router:
+            ...
+    """
+    conn = None
+    req_ctx = None
+
+    def __init__(self, bus='SESSION'):
+        self.bus = bus
+
+    async def __aenter__(self):
+        self.conn = await open_dbus_connection(self.bus)
+        self.req_ctx = DBusRouter(self.conn)
+        return await self.req_ctx.__aenter__()
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb):
+        await self.req_ctx.__aexit__(exc_type, exc_val, exc_tb)
+        await self.conn.close()
+
+
+class Proxy(ProxyBase):
+    """An asyncio proxy for calling D-Bus methods
+
+    You can call methods on the proxy object, such as ``await bus_proxy.Hello()``
+    to make a method call over D-Bus and wait for a reply. It will either
+    return a tuple of returned data, or raise :exc:`.DBusErrorResponse`.
+    The methods available are defined by the message generator you wrap.
+
+    :param msggen: A message generator object.
+    :param ~asyncio.DBusRouter router: Router to send and receive messages.
+    """
+    def __init__(self, msggen, router):
+        super().__init__(msggen)
+        self._router = router
+
+    def __repr__(self):
+        return 'Proxy({}, {})'.format(self._msggen, self._router)
+
+    def _method_call(self, make_msg):
+        async def inner(*args, **kwargs):
+            msg = make_msg(*args, **kwargs)
+            assert msg.header.message_type is MessageType.method_call
+            reply = await self._router.send_and_get_reply(msg)
+            return unwrap_msg(reply)
+
+        return inner