class Connection(object):
class TooManyChannels(ConnectionError):
'''This connection has too many channels open.
Non-fatal.'''
class InvalidChannel(ConnectionError):
'''The channel id does not correspond to an existing channel.
Non-fatal.'''
def __init__(self, **kwargs):
'''
Initialize the connection.
'''
self._debug = kwargs.get('debug', False)
self._logger = kwargs.get('logger', logging.root)
self._user = kwargs.get('user', 'guest')
self._password = kwargs.get('password', 'guest')
self._host = kwargs.get('host', 'localhost')
self._port = kwargs.get('port', 5672)
self._vhost = kwargs.get('vhost', '/')
self._connect_timeout = kwargs.get('connect_timeout', 5)
self._sock_opts = kwargs.get('sock_opts')
self._sock = None
self._heartbeat = kwargs.get('heartbeat')
self._open_cb = kwargs.get('open_cb')
self._close_cb = kwargs.get('close_cb')
self._login_method = kwargs.get('login_method', 'AMQPLAIN')
self._locale = kwargs.get('locale', 'en_US')
self._client_properties = kwargs.get('client_properties')
self._properties = LIBRARY_PROPERTIES.copy()
if self._client_properties:
self._properties.update(self._client_properties)
self._closed = False
self._connected = False
self._close_info = {
'reply_code': 0,
'reply_text': 'first connect',
'class_id': 0,
'method_id': 0
}
# Not sure what's better here, setdefaults or require the caller to pass
# the whole thing in.
self._class_map = kwargs.get('class_map', {}).copy()
self._class_map.setdefault(20, ChannelClass)
self._class_map.setdefault(40, ExchangeClass)
self._class_map.setdefault(50, QueueClass)
self._class_map.setdefault(60, BasicClass)
self._class_map.setdefault(90, TransactionClass)
self._channels = {
0: ConnectionChannel(self, 0, {})
}
# Login response seems a total hack of protocol
# Skip the length at the beginning
login_response = Writer()
login_response.write_table({'LOGIN': self._user,
'PASSWORD': self._password})
self._login_response = login_response.buffer()[4:]
self._channel_counter = 0
self._channel_max = USHORT_MAX
self._frame_max = USHORT_MAX
self._frames_read = 0
self._frames_written = 0
# Default to the socket strategy
transport = kwargs.get('transport', 'socket')
if not isinstance(transport, Transport):
if transport == 'event':
from haigha.transports.event_transport import EventTransport
self._transport = EventTransport(self)
elif transport == 'gevent':
from haigha.transports.gevent_transport import GeventTransport
self._transport = GeventTransport(self)
elif transport == 'gevent_pool':
from haigha.transports.gevent_transport import GeventPoolTransport
self._transport = GeventPoolTransport(self)
elif transport == 'socket':
from haigha.transports.socket_transport import SocketTransport
self._transport = SocketTransport(self)
else:
self._transport = transport
# Set these after the transport is initialized, so that we can access the
# synchronous property
self._synchronous = kwargs.get('synchronous', False)
self._synchronous_connect = \
kwargs.get('synchronous_connect', False) or self.synchronous
self._output_frame_buffer = []
self.connect(self._host, self._port)
@property
def logger(self):
return self._logger
@property
def debug(self):
return self._debug
@property
def frame_max(self):
return self._frame_max
@property
def channel_max(self):
return self._channel_max
@property
def frames_read(self):
'''Number of frames read in the lifetime of this connection.'''
return self._frames_read
@property
def frames_written(self):
'''Number of frames written in the lifetime of this connection.'''
return self._frames_written
@property
def closed(self):
'''Return the closed state of the connection.'''
return self._closed
@property
def close_info(self):
'''Return dict with information on why this connection is closed. Will
return None if the connections is open.'''
if (self._closed or not self._connected):
return self._close_info
else:
return None
@property
def transport(self):
'''Get the value of the current transport.'''
return self._transport
@property
def synchronous(self):
'''
True if transport is synchronous or the connection has been forced into
synchronous mode, False otherwise.
'''
if self._transport is None:
if self._close_info and len(self._close_info['reply_text']) > 0:
raise ConnectionClosed("connection is closed: %s : %s" %
(self._close_info['reply_code'],
self._close_info['reply_text']))
raise ConnectionClosed("connection is closed")
return self.transport.synchronous or self._synchronous
def connect(self, host, port):
'''
Connect to a host and port. Can be called directly, or is called by the
strategy as it tries to find and connect to hosts.
'''
# Clear the connect state immediately since we're no longer connected
# at this point.
self._connected = False
# Only after the socket has connected do we clear this state; closed must
# be False so that writes can be buffered in writePacket(). The closed
# state might have been set to True due to a socket error or a redirect.
self._host = "%s:%d" % (host, port)
self._closed = False
self._close_info = {
'reply_code': 0,
'reply_text': 'failed to connect to %s' % (self._host),
'class_id': 0,
'method_id': 0
}
self._transport.connect((host, port))
self._transport.write(PROTOCOL_HEADER)
if self._synchronous_connect:
# Have to queue this callback just after connect, it can't go into the
# constructor because the channel needs to be "always there" for frame
# processing, but the synchronous callback can't be added until after
# the protocol header has been written. This SHOULD be registered before
# the protocol header is written, in the case where the header bytes
# are written, but this thread/greenlet/context does not return until
# after another thread/greenlet/context has read and processed the
# recv_start frame. Without more re-write to add_sync_cb though, it will
# block on reading responses that will never arrive because the protocol
# header isn't written yet. TBD if needs refactoring. Could encapsulate
# entirely here, wherein read_frames exits if protocol header not yet
# written. Like other synchronous behaviors, adding this callback will
# result in a blocking frame read and process loop until _recv_start and
# any subsequent synchronous callbacks have been processed. In the event
# that this is /not/ a synchronous transport, but the caller wants the
# connect to be synchronous so as to ensure that the connection is ready,
# then do a read frame loop here.
self._channels[0].add_synchronous_cb(self._channels[0]._recv_start)
while not self._connected:
self.read_frames()
def disconnect(self):
'''
Disconnect from the current host, but do not update the closed state. After
the transport is disconnected, the closed state will be True if this is
called after a protocol shutdown, or False if the disconnect was in error.
TODO: do we really need closed vs. connected states? this only adds
complication and the whole reconnect process has been scrapped anyway.
'''
self._connected = False
if self._transport is not None:
try:
self._transport.disconnect()
except Exception:
self.logger.error("Failed to disconnect from %s",
self._host, exc_info=True)
raise
finally:
self._transport = None
###
### Transport methods
###
def transport_closed(self, **kwargs):
"""
Called by Transports when they close unexpectedly, not as a result of
Connection.disconnect().
TODO: document args
"""
msg = 'unknown cause'
self.logger.warning('transport to %s closed : %s' %
(self._host, kwargs.get('msg', msg)))
self._close_info = {
'reply_code': kwargs.get('reply_code', 0),
'reply_text': kwargs.get('msg', msg),
'class_id': kwargs.get('class_id', 0),
'method_id': kwargs.get('method_id', 0)
}
# We're not connected any more, but we're not closed without an explicit
# close call. This allows the strategy to distinguish the state.
# TODO: is this all BS?
self._connected = False
self._transport = None
# Call back to a user-provided close function
self._callback_close()
###
### Connection methods
###
def _next_channel_id(self):
'''Return the next possible channel id. Is a circular enumeration.'''
self._channel_counter += 1
if self._channel_counter >= self._channel_max:
self._channel_counter = 1
return self._channel_counter
def channel(self, channel_id=None, synchronous=False):
"""
Fetch a Channel object identified by the numeric channel_id, or
create that object if it doesn't already exist. If channel_id is not
None but no channel exists for that id, will raise InvalidChannel. If
there are already too many channels open, will raise TooManyChannels.
If synchronous=True, then the channel will act synchronous in all cases
where a protocol method supports `nowait=False`, or where there is an
implied callback in the protocol.
"""
if channel_id is None:
# adjust for channel 0
if len(self._channels) - 1 >= self._channel_max:
raise Connection.TooManyChannels(
"%d channels already open, max %d",
len(self._channels) - 1,
self._channel_max)
channel_id = self._next_channel_id()
while channel_id in self._channels:
channel_id = self._next_channel_id()
elif channel_id in self._channels:
return self._channels[channel_id]
else:
raise Connection.InvalidChannel("%s is not a valid channel id",
channel_id)
# Call open() here so that ConnectionChannel doesn't have it called. Could
# also solve this other ways, but it's a HACK regardless.
ch = Channel(self, channel_id, self._class_map,
synchronous=synchronous)
self._channels[channel_id] = ch
ch.add_close_listener(self._channel_closed)
ch.open()
return ch
def _channel_closed(self, channel):
'''
Close listener on a channel.
'''
try:
del self._channels[channel.channel_id]
except KeyError:
pass
def close(self, reply_code=0, reply_text='',
class_id=0, method_id=0, disconnect=False):
'''
Close this connection.
'''
self._close_info = {
'reply_code': reply_code,
'reply_text': reply_text,
'class_id': class_id,
'method_id': method_id
}
if disconnect:
self._closed = True
self.disconnect()
self._callback_close()
else:
self._channels[0].close()
def _callback_open(self):
'''
Callback to any open handler that was provided in the ctor. Handler is
responsible for exceptions.
'''
if self._open_cb:
self._open_cb()
def _callback_close(self):
'''
Callback to any close handler that was provided in the ctor. Handler is
responsible for exceptions.
'''
if self._close_cb:
self._close_cb()
def read_frames(self):
'''
Read frames from the transport and process them. Some transports may choose
to do this in the background, in several threads, and so on.
'''
# It's possible in a concurrent environment that our transport handle has
# gone away, so handle that cleanly.
# TODO: Consider moving this block into Translator base class. In many
# ways it belongs there. One of the problems though is that this is
# essentially the read loop. Each Transport has different rules for how to
# kick this off, and in the case of gevent, this is how a blocking call to
# read from the socket is kicked off.
if self._transport is None:
return
# Send a heartbeat (if needed)
self._channels[0].send_heartbeat()
data = self._transport.read(self._heartbeat)
if data is None:
return
reader = Reader(data)
p_channels = set()
try:
for frame in Frame.read_frames(reader):
if self._debug > 1:
self.logger.debug("READ: %s", frame)
self._frames_read += 1
ch = self.channel(frame.channel_id)
ch.buffer_frame(frame)
p_channels.add(ch)
except Frame.FrameError as e:
# Frame error in the peer, disconnect
self.close(reply_code=501,
reply_text='frame error from %s : %s' % (self._host, str(e)),
class_id=0, method_id=0, disconnect=True)
raise ConnectionClosed("connection is closed: %s : %s" %
(self._close_info['reply_code'],
self._close_info['reply_text']))
self._transport.process_channels(p_channels)
# HACK: read the buffer contents and re-buffer. Would prefer to pass
# buffer back, but there's no good way of asking the total size of the
# buffer, comparing to tell(), and then re-buffering. There's also no
# ability to clear the buffer up to the current position. It would be
# awesome if we could free that memory without a new allocation.
if reader.tell() < len(data):
self._transport.buffer(data[reader.tell():])
def _flush_buffered_frames(self):
'''
Callback when protocol has been initialized on channel 0 and we're ready
to send out frames to set up any channels that have been created.
'''
# In the rare case (a bug) where this is called but send_frame thinks
# they should be buffered, don't clobber.
frames = self._output_frame_buffer
self._output_frame_buffer = []
for frame in frames:
self.send_frame(frame)
def send_frame(self, frame):
'''
Send a single frame. If there is no transport or we're not connected yet,
append to the output buffer, else send immediately to the socket. This is
called from within the MethodFrames.
'''
if self._closed:
if self._close_info and len(self._close_info['reply_text']) > 0:
raise ConnectionClosed("connection is closed: %s : %s" %
(self._close_info['reply_code'],
self._close_info['reply_text']))
raise ConnectionClosed("connection is closed")
if self._transport is None or \
(not self._connected and frame.channel_id != 0):
self._output_frame_buffer.append(frame)
return
if self._debug > 1:
self.logger.debug("WRITE: %s", frame)
buf = bytearray()
frame.write_frame(buf)
if len(buf) > self._frame_max:
self.close(reply_code=501,
reply_text='attempted to send frame of %d bytes, frame max %d' % (len(buf), self._frame_max),
class_id=0, method_id=0, disconnect=True)
raise ConnectionClosed("connection is closed: %s : %s" %
(self._close_info['reply_code'],
self._close_info['reply_text']))
self._transport.write(buf)
self._frames_written += 1
class Connection(object):
class TooManyChannels(ConnectionError):
'''This connection has too many channels open. Non-fatal.'''
class InvalidChannel(ConnectionError):
'''The channel id does not correspond to an existing channel. Non-fatal.'''
def __init__(self, **kwargs):
'''
Initialize the connection.
'''
self._debug = kwargs.get('debug', False)
self._logger = kwargs.get('logger', root_logger)
self._user = kwargs.get('user', 'guest')
self._password = kwargs.get('password', 'guest')
self._host = kwargs.get('host', 'localhost')
self._port = kwargs.get('port', 5672)
self._vhost = kwargs.get('vhost', '/')
self._connect_timeout = kwargs.get('connect_timeout', 5)
self._sock_opts = kwargs.get('sock_opts')
self._sock = None
self._heartbeat = kwargs.get('heartbeat')
self._open_cb = kwargs.get('open_cb')
self._close_cb = kwargs.get('close_cb')
self._login_method = kwargs.get('login_method', 'AMQPLAIN')
self._locale = kwargs.get('locale', 'en_US')
self._client_properties = kwargs.get('client_properties')
self._properties = LIBRARY_PROPERTIES.copy()
if self._client_properties:
self._properties.update(self._client_properties)
self._closed = False
self._connected = False
self._close_info = {
'reply_code': 0,
'reply_text': 'first connect',
'class_id': 0,
'method_id': 0
}
# Not sure what's better here, setdefaults or require the caller to pass
# the whole thing in.
self._class_map = kwargs.get('class_map', {}).copy()
self._class_map.setdefault(20, ChannelClass)
self._class_map.setdefault(40, ExchangeClass)
self._class_map.setdefault(50, QueueClass)
self._class_map.setdefault(60, BasicClass)
self._class_map.setdefault(90, TransactionClass)
self._channels = {0: ConnectionChannel(self, 0, {})}
# Login response seems a total hack of protocol
# Skip the length at the beginning
login_response = Writer()
login_response.write_table({
'LOGIN': self._user,
'PASSWORD': self._password
})
self._login_response = login_response.buffer()[4:]
self._channel_counter = 0
self._channel_max = 65535
self._frame_max = 65535
self._frames_read = 0
self._frames_written = 0
# Default to the socket strategy
transport = kwargs.get('transport', 'socket')
if not isinstance(transport, Transport):
if transport == 'event':
from haigha.transports.event_transport import EventTransport
self._transport = EventTransport(self)
elif transport == 'gevent':
from haigha.transports.gevent_transport import GeventTransport
self._transport = GeventTransport(self)
elif transport == 'gevent_pool':
from haigha.transports.gevent_transport import GeventPoolTransport
self._transport = GeventPoolTransport(self)
elif transport == 'socket':
from haigha.transports.socket_transport import SocketTransport
self._transport = SocketTransport(self)
else:
self._transport = transport
self._output_frame_buffer = []
self.connect(self._host, self._port)
@property
def logger(self):
return self._logger
@property
def debug(self):
return self._debug
@property
def frame_max(self):
return self._frame_max
@property
def channel_max(self):
return self._channel_max
@property
def frames_read(self):
'''Number of frames read in the lifetime of this connection.'''
return self._frames_read
@property
def frames_written(self):
'''Number of frames written in the lifetime of this connection.'''
return self._frames_written
@property
def close_info(self):
'''Return dict with information on why this connection is closed. Will
return None if the connections is open.'''
return self._close_info if (self._closed
or not self._connected) else None
@property
def transport(self):
'''Get the value of the current transport.'''
return self._transport
@property
def synchronous(self):
'''True if transport is synchronous, False otherwise.'''
return self.transport.synchronous
def connect(self, host, port):
'''
Connect to a host and port. Can be called directly, or is called by the
strategy as it tries to find and connect to hosts.
'''
# Clear the connect state immediately since we're no longer connected
# at this point.
self._connected = False
# Only after the socket has connected do we clear this state; closed must
# be False so that writes can be buffered in writePacket(). The closed
# state might have been set to True due to a socket error or a redirect.
self._host = "%s:%d" % (host, port)
self._closed = False
self._close_info = {
'reply_code': 0,
'reply_text': 'failed to connect to %s' % (self._host),
'class_id': 0,
'method_id': 0
}
self._transport.connect((host, port))
self._transport.write(PROTOCOL_HEADER)
while self.synchronous and not self._connected:
self.read_frames()
def disconnect(self):
'''
Disconnect from the current host, but do not update the closed state. After
the transport is disconnected, the closed state will be True if this is
called after a protocol shutdown, or False if the disconnect was in error.
TODO: do we really need closed vs. connected states? this only adds
complication and the whole reconnect process has been scrapped anyway.
'''
self._connected = False
if self._transport != None:
try:
self._transport.disconnect()
except Exception:
self.logger.error("Failed to disconnect from %s",
self._host,
exc_info=True)
raise
finally:
self._transport = None
###
### Transport methods
###
def transport_closed(self, **kwargs):
"""
Called by Transports when they close unexpectedly, not as a result of
Connection.disconnect().
TODO: document args
"""
msg = 'transport to %s closed : unknown cause' % (self._host)
self.logger.warning(kwargs.get('msg', msg))
self._close_info = {
'reply_code': kwargs.get('reply_code', 0),
'reply_text': kwargs.get('msg', msg),
'class_id': kwargs.get('class_id', 0),
'method_id': kwargs.get('method_id', 0)
}
# We're not connected any more, but we're not closed without an explicit
# close call. This allows the strategy to distinguish the state.
# TODO: is this all BS?
self._connected = False
self._transport = None
# Call back to a user-provided close function
self._callback_close()
###
### Connection methods
###
def _next_channel_id(self):
'''Return the next possible channel id. Is a circular enumeration.'''
self._channel_counter += 1
if self._channel_counter >= self._channel_max:
self._channel_counter = 1
return self._channel_counter
def channel(self, channel_id=None):
"""
Fetch a Channel object identified by the numeric channel_id, or
create that object if it doesn't already exist. If channel_id is not
None but no channel exists for that id, will raise InvalidChannel. If
there are already too many channels open, will raise TooManyChannels.
"""
if channel_id is None:
# adjust for channel 0
if len(self._channels) - 1 >= self._channel_max:
raise Connection.TooManyChannels(
"%d channels already open, max %d",
len(self._channels) - 1, self._channel_max)
channel_id = self._next_channel_id()
while channel_id in self._channels:
channel_id = self._next_channel_id()
elif channel_id in self._channels:
return self._channels[channel_id]
else:
raise Connection.InvalidChannel("%s is not a valid channel id",
channel_id)
# Call open() here so that ConnectionChannel doesn't have it called. Could
# also solve this other ways, but it's a HACK regardless.
rval = Channel(self, channel_id, self._class_map)
self._channels[channel_id] = rval
rval.add_close_listener(self._channel_closed)
rval.open()
return rval
def _channel_closed(self, channel):
'''
Close listener on a channel.
'''
try:
del self._channels[channel.channel_id]
except KeyError:
pass
def close(self, reply_code=0, reply_text='', class_id=0, method_id=0):
'''
Close this connection.
'''
self._close_info = {
'reply_code': reply_code,
'reply_text': reply_text,
'class_id': class_id,
'method_id': method_id
}
self._channels[0].close()
def _callback_open(self):
'''
Callback to any open handler that was provided in the ctor. Handler is
responsible for exceptions.
'''
if self._open_cb:
self._open_cb()
def _callback_close(self):
'''
Callback to any close handler that was provided in the ctor. Handler is
responsible for exceptions.
'''
if self._close_cb:
self._close_cb()
def read_frames(self):
'''
Read frames from the transport and process them. Some transports may choose
to do this in the background, in several threads, and so on.
'''
# It's possible in a concurrent environment that our transport handle has
# gone away, so handle that cleanly.
# TODO: Consider moving this block into Translator base class. In many
# ways it belongs there. One of the problems though is that this is
# essentially the read loop. Each Transport has different rules for how to
# kick this off, and in the case of gevent, this is how a blocking call to
# read from the socket is kicked off.
if self._transport is None:
return
# Send a heartbeat (if needed)
self._channels[0].send_heartbeat()
data = self._transport.read(self._heartbeat)
if data is None:
return
reader = Reader(data)
p_channels = set()
for frame in Frame.read_frames(reader):
if self._debug > 1:
self.logger.debug("READ: %s", frame)
self._frames_read += 1
ch = self.channel(frame.channel_id)
ch.buffer_frame(frame)
p_channels.add(ch)
self._transport.process_channels(p_channels)
# HACK: read the buffer contents and re-buffer. Would prefer to pass
# buffer back, but there's no good way of asking the total size of the
# buffer, comparing to tell(), and then re-buffering. There's also no
# ability to clear the buffer up to the current position. It would be
# awesome if we could free that memory without a new allocation.
if reader.tell() < len(data):
self._transport.buffer(data[reader.tell():])
def _flush_buffered_frames(self):
'''
Callback when protocol has been initialized on channel 0 and we're ready
to send out frames to set up any channels that have been created.
'''
# In the rare case (a bug) where this is called but send_frame thinks
# they should be buffered, don't clobber.
frames = self._output_frame_buffer
self._output_frame_buffer = []
for frame in frames:
self.send_frame(frame)
def send_frame(self, frame):
'''
Send a single frame. If there is no transport or we're not connected yet,
append to the output buffer, else send immediately to the socket. This is
called from within the MethodFrames.
'''
if self._closed:
if self._close_info and len(self._close_info['reply_text']) > 0:
raise ConnectionClosed("connection is closed: %s : %s"%\
(self._close_info['reply_code'],self._close_info['reply_text']) )
raise ConnectionClosed("connection is closed")
if self._transport == None or (not self._connected
and frame.channel_id != 0):
self._output_frame_buffer.append(frame)
return
if self._debug > 1:
self.logger.debug("WRITE: %s", frame)
buf = bytearray()
frame.write_frame(buf)
self._transport.write(buf)
self._frames_written += 1
class Connection(object):
class TooManyChannels(ConnectionError):
'''This connection has too many channels open. Non-fatal.'''
class InvalidChannel(ConnectionError):
'''
The channel id does not correspond to an existing channel. Non-fatal.
'''
def __init__(self, **kwargs):
'''
Initialize the connection.
'''
self._debug = kwargs.get('debug', False)
self._logger = kwargs.get('logger', root_logger)
self._user = kwargs.get('user', 'guest')
self._password = kwargs.get('password', 'guest')
self._host = kwargs.get('host', 'localhost')
self._port = kwargs.get('port', 5672)
self._vhost = kwargs.get('vhost', '/')
self._connect_timeout = kwargs.get('connect_timeout', 5)
self._sock_opts = kwargs.get('sock_opts')
self._sock = None
self._heartbeat = kwargs.get('heartbeat')
self._open_cb = kwargs.get('open_cb')
self._close_cb = kwargs.get('close_cb')
self._login_method = kwargs.get('login_method', 'AMQPLAIN')
self._locale = kwargs.get('locale', 'en_US')
self._client_properties = kwargs.get('client_properties')
self._properties = LIBRARY_PROPERTIES.copy()
if self._client_properties:
self._properties.update(self._client_properties)
self._closed = False
self._connected = False
self._close_info = {
'reply_code': 0,
'reply_text': 'first connect',
'class_id': 0,
'method_id': 0
}
# Not sure what's better here, setdefaults or require the caller to
# pass the whole thing in.
self._class_map = kwargs.get('class_map', {}).copy()
self._class_map.setdefault(20, ChannelClass)
self._class_map.setdefault(40, ExchangeClass)
self._class_map.setdefault(50, QueueClass)
self._class_map.setdefault(60, BasicClass)
self._class_map.setdefault(90, TransactionClass)
self._channels = {0: ConnectionChannel(self, 0, {})}
self._last_octet_time = None
# Login response seems a total hack of protocol
# Skip the length at the beginning
login_response = Writer()
login_response.write_table({
'LOGIN': self._user,
'PASSWORD': self._password
})
self._login_response = login_response.buffer()[4:]
self._channel_counter = 0
self._channel_max = 65535
self._frame_max = 65535
self._frames_read = 0
self._frames_written = 0
# Default to the socket strategy
transport = kwargs.get('transport', 'socket')
if not isinstance(transport, Transport):
if transport == 'event':
from haigha.transports.event_transport import EventTransport
self._transport = EventTransport(self)
elif transport == 'gevent':
from haigha.transports.gevent_transport import GeventTransport
self._transport = GeventTransport(self)
elif transport == 'gevent_pool':
from haigha.transports.gevent_transport import \
GeventPoolTransport
self._transport = GeventPoolTransport(self, **kwargs)
elif transport == 'socket':
from haigha.transports.socket_transport import SocketTransport
self._transport = SocketTransport(self)
else:
self._transport = transport
# Set these after the transport is initialized, so that we can access
# the synchronous property
self._synchronous = kwargs.get('synchronous', False)
self._synchronous_connect = kwargs.get('synchronous_connect',
False) or self.synchronous
self._output_frame_buffer = []
self.connect(self._host, self._port)
@property
def logger(self):
return self._logger
@property
def debug(self):
return self._debug
@property
def frame_max(self):
return self._frame_max
@property
def channel_max(self):
return self._channel_max
@property
def frames_read(self):
'''Number of frames read in the lifetime of this connection.'''
return self._frames_read
@property
def frames_written(self):
'''Number of frames written in the lifetime of this connection.'''
return self._frames_written
@property
def closed(self):
'''Return the closed state of the connection.'''
return self._closed
@property
def close_info(self):
'''
Return dict with information on why this connection is closed. Will
return None if the connections is open.
'''
return self._close_info if (self._closed
or not self._connected) else None
@property
def transport(self):
'''Get the value of the current transport.'''
return self._transport
@property
def synchronous(self):
'''
True if transport is synchronous or the connection has been forced
into synchronous mode, False otherwise.
'''
if self._transport is None:
if self._close_info and len(self._close_info['reply_text']) > 0:
raise ConnectionClosed("connection is closed: %s : %s" %
(self._close_info['reply_code'],
self._close_info['reply_text']))
raise ConnectionClosed("connection is closed")
return self.transport.synchronous or self._synchronous
def connect(self, host, port):
'''
Connect to a host and port.
'''
# Clear the connect state immediately since we're no longer connected
# at this point.
self._connected = False
# Only after the socket has connected do we clear this state; closed
# must be False so that writes can be buffered in writePacket(). The
# closed state might have been set to True due to a socket error or a
# redirect.
self._host = "%s:%d" % (host, port)
self._closed = False
self._close_info = {
'reply_code': 0,
'reply_text': 'failed to connect to %s' % (self._host),
'class_id': 0,
'method_id': 0
}
self._transport.connect((host, port))
self._transport.write(PROTOCOL_HEADER)
self._last_octet_time = time.time()
if self._synchronous_connect:
# Have to queue this callback just after connect, it can't go
# into the constructor because the channel needs to be
# "always there" for frame processing, but the synchronous
# callback can't be added until after the protocol header has
# been written. This SHOULD be registered before the protocol
# header is written, in the case where the header bytes are
# written, but this thread/greenlet/context does not return until
# after another thread/greenlet/context has read and processed the
# recv_start frame. Without more re-write to add_sync_cb though,
# it will block on reading responses that will never arrive
# because the protocol header isn't written yet. TBD if needs
# refactoring. Could encapsulate entirely here, wherein
# read_frames exits if protocol header not yet written. Like other
# synchronous behaviors, adding this callback will result in a
# blocking frame read and process loop until _recv_start and any
# subsequent synchronous callbacks have been processed. In the
# event that this is /not/ a synchronous transport, but the
# caller wants the connect to be synchronous so as to ensure that
# the connection is ready, then do a read frame loop here.
self._channels[0].add_synchronous_cb(self._channels[0]._recv_start)
while not self._connected:
self.read_frames()
def disconnect(self):
'''
Disconnect from the current host, but do not update the closed state.
After the transport is disconnected, the closed state will be True if
this is called after a protocol shutdown, or False if the disconnect
was in error.
TODO: do we really need closed vs. connected states? this only adds
complication and the whole reconnect process has been scrapped anyway.
'''
self._connected = False
if self._transport is not None:
try:
self._transport.disconnect()
except Exception:
self.logger.error("Failed to disconnect from %s",
self._host,
exc_info=True)
raise
finally:
self._transport = None
###
# Transport methods
###
def transport_closed(self, **kwargs):
"""
Called by Transports when they close unexpectedly, not as a result of
Connection.disconnect().
TODO: document args
"""
msg = 'unknown cause'
self.logger.warning('transport to %s closed : %s' %
(self._host, kwargs.get('msg', msg)))
self._close_info = {
'reply_code': kwargs.get('reply_code', 0),
'reply_text': kwargs.get('msg', msg),
'class_id': kwargs.get('class_id', 0),
'method_id': kwargs.get('method_id', 0)
}
# We're not connected any more, but we're not closed without an
# explicit close call.
self._connected = False
self._transport = None
# Call back to a user-provided close function
self._callback_close()
###
# Connection methods
###
def _next_channel_id(self):
'''Return the next possible channel id. Is a circular enumeration.'''
self._channel_counter += 1
if self._channel_counter >= self._channel_max:
self._channel_counter = 1
return self._channel_counter
def channel(self, channel_id=None, synchronous=False):
"""
Fetch a Channel object identified by the numeric channel_id, or
create that object if it doesn't already exist. If channel_id is not
None but no channel exists for that id, will raise InvalidChannel. If
there are already too many channels open, will raise TooManyChannels.
If synchronous=True, then the channel will act synchronous in all cases
where a protocol method supports `nowait=False`, or where there is an
implied callback in the protocol.
"""
if channel_id is None:
# adjust for channel 0
if len(self._channels) - 1 >= self._channel_max:
raise Connection.TooManyChannels(
"%d channels already open, max %d",
len(self._channels) - 1, self._channel_max)
channel_id = self._next_channel_id()
while channel_id in self._channels:
channel_id = self._next_channel_id()
elif channel_id in self._channels:
return self._channels[channel_id]
else:
raise Connection.InvalidChannel("%s is not a valid channel id",
channel_id)
# Call open() here so that ConnectionChannel doesn't have it called.
# Could also solve this other ways, but it's a HACK regardless.
rval = Channel(self,
channel_id,
self._class_map,
synchronous=synchronous)
self._channels[channel_id] = rval
rval.add_close_listener(self._channel_closed)
rval.open()
return rval
def _channel_closed(self, channel):
'''
Close listener on a channel.
'''
try:
del self._channels[channel.channel_id]
except KeyError:
pass
def close(self,
reply_code=0,
reply_text='',
class_id=0,
method_id=0,
disconnect=False):
'''
Close this connection.
'''
self._close_info = {
'reply_code': reply_code,
'reply_text': reply_text,
'class_id': class_id,
'method_id': method_id
}
if disconnect:
self._closed = True
self.disconnect()
self._callback_close()
else:
self._channels[0].close()
def _callback_open(self):
'''
Callback to any open handler that was provided in the ctor. Handler is
responsible for exceptions.
'''
if self._open_cb:
self._open_cb()
def _callback_close(self):
'''
Callback to any close handler that was provided in the ctor. Handler is
responsible for exceptions.
'''
if self._close_cb:
self._close_cb()
def read_frames(self):
'''
Read frames from the transport and process them. Some transports may
choose to do this in the background, in several threads, and so on.
'''
# It's possible in a concurrent environment that our transport handle
# has gone away, so handle that cleanly.
# TODO: Consider moving this block into Translator base class. In many
# ways it belongs there. One of the problems though is that this is
# essentially the read loop. Each Transport has different rules for
# how to kick this off, and in the case of gevent, this is how a
# blocking call to read from the socket is kicked off.
if self._transport is None:
return
# Send a heartbeat (if needed)
self._channels[0].send_heartbeat()
data = self._transport.read(self._heartbeat)
current_time = time.time()
if data is None:
# Wait for 2 heartbeat intervals before giving up. See AMQP 4.2.7:
# "If a peer detects no incoming traffic (i.e. received octets) for two heartbeat intervals or longer,
# it should close the connection"
if self._heartbeat and (current_time - self._last_octet_time >
2 * self._heartbeat):
msg = 'Heartbeats not received from %s for %d seconds' % (
self._host, 2 * self._heartbeat)
self.transport_closed(msg=msg)
raise ConnectionClosed('Connection is closed: ' + msg)
return
self._last_octet_time = current_time
reader = Reader(data)
p_channels = set()
try:
for frame in Frame.read_frames(reader):
if self._debug > 1:
self.logger.debug("READ: %s", frame)
self._frames_read += 1
ch = self.channel(frame.channel_id)
ch.buffer_frame(frame)
p_channels.add(ch)
except Frame.FrameError as e:
# Frame error in the peer, disconnect
self.close(reply_code=501,
reply_text='frame error from %s : %s' %
(self._host, str(e)),
class_id=0,
method_id=0,
disconnect=True)
raise ConnectionClosed("connection is closed: %s : %s" %
(self._close_info['reply_code'],
self._close_info['reply_text']))
# NOTE: we process channels after buffering unused data in order to
# preserve the integrity of the input stream in case a channel needs to
# read input, such as when a channel framing error necessitates the use
# of the synchronous channel.close method. See `Channel.process_frames`.
#
# HACK: read the buffer contents and re-buffer. Would prefer to pass
# buffer back, but there's no good way of asking the total size of the
# buffer, comparing to tell(), and then re-buffering. There's also no
# ability to clear the buffer up to the current position. It would be
# awesome if we could free that memory without a new allocation.
if reader.tell() < len(data):
self._transport.buffer(data[reader.tell():])
self._transport.process_channels(p_channels)
def _flush_buffered_frames(self):
'''
Callback when protocol has been initialized on channel 0 and we're
ready to send out frames to set up any channels that have been
created.
'''
# In the rare case (a bug) where this is called but send_frame thinks
# they should be buffered, don't clobber.
frames = self._output_frame_buffer
self._output_frame_buffer = []
for frame in frames:
self.send_frame(frame)
def send_frame(self, frame):
'''
Send a single frame. If there is no transport or we're not connected
yet, append to the output buffer, else send immediately to the socket.
This is called from within the MethodFrames.
'''
if self._closed:
if self._close_info and len(self._close_info['reply_text']) > 0:
raise ConnectionClosed("connection is closed: %s : %s" %
(self._close_info['reply_code'],
self._close_info['reply_text']))
raise ConnectionClosed("connection is closed")
if self._transport is None or \
(not self._connected and frame.channel_id != 0):
self._output_frame_buffer.append(frame)
return
if self._debug > 1:
self.logger.debug("WRITE: %s", frame)
buf = bytearray()
frame.write_frame(buf)
if len(buf) > self._frame_max:
self.close(
reply_code=501,
reply_text='attempted to send frame of %d bytes, frame max %d'
% (len(buf), self._frame_max),
class_id=0,
method_id=0,
disconnect=True)
raise ConnectionClosed("connection is closed: %s : %s" %
(self._close_info['reply_code'],
self._close_info['reply_text']))
self._transport.write(buf)
self._frames_written += 1