def f(self, *args):
result = command_class(name, args, partial(callback, self))
if self.__run_task is None:
raise ConnectionError("Can not send command to disconnected client")
self.__commandqueue.put_nowait(result)
self._nudge_idle()
return result
def f(self, *args):
result = command_class(name, args, partial(callback, self))
if self.__run_task is None:
raise ConnectionError(
"Can not send command to disconnected client")
try:
self.__command_queue.put_nowait(result)
except asyncio.QueueFull as e:
e.args = (
"Command queue overflowing; this indicates the"
" application sending commands in an uncontrolled"
" fashion without awaiting them, and typically"
" indicates a memory leak.", )
# While we *could* indicate to the queued result that it has
# yet to send its request, that'd practically create a queue of
# awaited items in the user application that's growing
# unlimitedly, eliminating any chance of timely responses.
# Furthermore, the author sees no practical use case that's not
# violating MPD's guidance of "Do not manage a client-side copy
# of MPD's database". If a use case *does* come up, any change
# would need to maintain the property of providing backpressure
# information. That would require an API change.
raise
self._end_idle()
# Careful: There can't be any await points between the queue
# appending and the write
try:
self._write_command(result._command, result._args)
except BaseException as e:
self.disconnect()
result.set_exception(e)
return result
async def connect(self, host, port=6600, loop=None):
self.__loop = loop
if "/" in host:
r, w = await asyncio.open_unix_connection(host, loop=loop)
else:
r, w = await asyncio.open_connection(host, port, loop=loop)
self.__rfile, self.__wfile = r, w
self.__commandqueue = asyncio.Queue(loop=loop)
self.__idle_results = asyncio.Queue(
loop=loop) #: a queue of CommandResult("idle") futures
self.__idle_consumers = [
] #: list of (subsystem-list, callbacks) tuples
try:
helloline = await asyncio.wait_for(self.__readline(), timeout=5)
except asyncio.TimeoutError:
self.disconnect()
raise ConnectionError(
"No response from server while reading MPD hello")
# FIXME should be reusable w/o reaching in
SyncMPDClient._hello(self, helloline)
self.__run_task = asyncio.Task(self.__run())
self.__idle_task = asyncio.Task(self.__distribute_idle_results())
async def idle(self, subsystems=()):
if self.__idle_consumers is None:
raise ConnectionError(
"Can not start idle on a disconnected client")
interests_before = self._get_idle_interests()
# A queue accepting either a list of things that changed in a single
# idle cycle, or an exception to be raised
changes = asyncio.Queue()
try:
entry = (subsystems, changes.put_nowait)
self.__idle_consumers.append(entry)
if self._get_idle_interests != interests_before:
# Technically this does not enter idle *immediately* but rather
# only after any commands after IMMEDIATE_COMMAND_TIMEOUT;
# practically that should be a good thing.
self._end_idle()
while True:
item = await changes.get()
if isinstance(item, Exception):
raise item
yield item
finally:
if self.__idle_consumers is not None:
self.__idle_consumers.remove(entry)
async def _read_line(self):
line = await self.__readline()
if not line.endswith("\n"):
raise ConnectionError("Connection lost while reading line")
line = line.rstrip("\n")
if line.startswith(ERROR_PREFIX):
error = line[len(ERROR_PREFIX):].strip()
raise CommandError(error)
if line == SUCCESS:
return None
return line
def disconnect(self):
if (self.__run_task is not None
): # is None eg. when connection fails in .connect()
self.__run_task.cancel()
if self.__wfile is not None:
self.__wfile.close()
self.__rfile = self.__wfile = None
self.__run_task = None
self.__command_queue = None
if self.__idle_consumers is not None:
# copying the list as each raising callback will remove itself from __idle_consumers
for subsystems, callback in list(self.__idle_consumers):
callback(ConnectionError())
self.__idle_consumers = None
async def connect(self, host, port=6600, loop=None):
if "/" in host:
r, w = await asyncio.open_unix_connection(host, loop=loop)
else:
r, w = await asyncio.open_connection(host, port, loop=loop)
self.__rfile, self.__wfile = r, w
self.__command_queue = asyncio.Queue(maxsize=self.COMMAND_QUEUE_LENGTH)
self.__idle_consumers = [] #: list of (subsystem-list, callbacks) tuples
try:
helloline = await asyncio.wait_for(self.__readline(), timeout=5)
except asyncio.TimeoutError:
self.disconnect()
raise ConnectionError("No response from server while reading MPD hello")
# FIXME should be reusable w/o reaching in
SyncMPDClient._hello(self, helloline)
self.__run_task = asyncio.Task(self.__run())
async def idle(self, subsystems=()):
if self.__idle_consumers is None:
raise ConnectionError(
"Can not start idle on a disconnected client")
interests_before = self._get_idle_interests()
changes = asyncio.Queue()
try:
entry = (subsystems, changes.put_nowait)
self.__idle_consumers.append(entry)
if self._get_idle_interests != interests_before:
# Technically this does not enter idle *immediately* but rather
# only after any commands after IMMEDIATE_COMMAND_TIMEOUT;
# practically that should be a good thing.
self._end_idle()
while True:
yield await changes.get()
finally:
if self.__idle_consumers is not None:
self.__idle_consumers.remove(entry)
async def _read_binary(self):
obj = {}
while True:
line = await self._read_line()
if line is None:
break
key, value = self._parse_pair(line, ": ")
if key == "binary":
chunk_size = int(value)
value = await self._read_chunk(chunk_size)
if await self.__rfile.readexactly(1) != b"\n":
# newline after binary content
self.disconnect()
raise ConnectionError("Connection lost while reading line")
obj[key] = value
return obj
async def _read_chunk(self, length):
try:
return await self.__rfile.readexactly(length)
except asyncio.IncompleteReadError:
raise ConnectionError("Connection lost while reading binary")