eventlet.green.zmq
– ØMQ support¶
pyzmq
[1] is a python binding to the C++ ØMQ [2] library written in Cython [3].
eventlet.green.zmq
is greenthread aware version of pyzmq.
The zmq
module wraps the Socket
and Context
found in pyzmq
to be non blocking
-
class
eventlet.green.zmq.
Context
(io_threads=1, **kwargs)¶ Bases:
zmq.sugar.context.Context
Subclass of
zmq.Context
-
class
eventlet.green.zmq.
Socket
(context, socket_type)¶ Bases:
zmq.sugar.socket.Socket
Green version of :class:`zmq.core.socket.Socket
- The following three methods are always overridden:
- send
- recv
- getsockopt
To ensure that the
zmq.NOBLOCK
flag is set and that sending or receiving is deferred to the hub (usingeventlet.hubs.trampoline()
) if azmq.EAGAIN
(retry) error is raised- For some socket types, the following methods are also overridden:
- send_multipart
- recv_multipart
-
recv
(flags=0, copy=True, track=False)¶ Receive a message.
With flags=NOBLOCK, this raises
ZMQError
if no messages have arrived; otherwise, this waits until a message arrives. SeePoller
for more general non-blocking I/O.- flags : int
- 0 or NOBLOCK.
- copy : bool
- Should the message be received in a copying or non-copying manner? If False a Frame object is returned, if True a string copy of message is returned.
- track : bool
- Should the message be tracked for notification that ZMQ has finished with it? (ignored if copy=True)
- msg : bytes or Frame
- The received message frame. If copy is False, then it will be a Frame, otherwise it will be bytes.
- ZMQError
- for any of the reasons zmq_msg_recv might fail (including if NOBLOCK is set and no new messages have arrived).
-
send
(msg, flags=0, copy=True, track=False)¶ Send a single zmq message frame on this socket.
This queues the message to be sent by the IO thread at a later time.
With flags=NOBLOCK, this raises
ZMQError
if the queue is full; otherwise, this waits until space is available. SeePoller
for more general non-blocking I/O.- data : bytes, Frame, memoryview
- The content of the message. This can be any object that provides the Python buffer API (i.e. memoryview(data) can be called).
- flags : int
- 0, NOBLOCK, SNDMORE, or NOBLOCK|SNDMORE.
- copy : bool
- Should the message be sent in a copying or non-copying manner.
- track : bool
- Should the message be tracked for notification that ZMQ has finished with it? (ignored if copy=True)
- routing_id : int
- For use with SERVER sockets
- group : str
- For use with RADIO sockets
- None : if copy or not track
- None if message was sent, raises an exception otherwise.
- MessageTracker : if track and not copy
- a MessageTracker object, whose pending property will be True until the send is completed.
- TypeError
- If a unicode object is passed
- ValueError
- If track=True, but an untracked Frame is passed.
- ZMQError
- If the send does not succeed for any reason (including if NOBLOCK is set and the outgoing queue is full).
Changed in version 17.0: DRAFT support for routing_id and group arguments.
-
bind
(addr)¶ Bind the socket to an address.
This causes the socket to listen on a network port. Sockets on the other side of this connection will use
Socket.connect(addr)
to connect to this socket.- addr : str
- The address string. This has the form ‘protocol://interface:port’, for example ‘tcp://127.0.0.1:5555’. Protocols supported include tcp, udp, pgm, epgm, inproc and ipc. If the address is unicode, it is encoded to utf-8 first.
-
bind_to_random_port
(addr, min_port=49152, max_port=65536, max_tries=100)¶ Bind this socket to a random port in a range.
If the port range is unspecified, the system will choose the port.
- addr : str
- The address string without the port to pass to
Socket.bind()
. - min_port : int, optional
- The minimum port in the range of ports to try (inclusive).
- max_port : int, optional
- The maximum port in the range of ports to try (exclusive).
- max_tries : int, optional
- The maximum number of bind attempts to make.
- port : int
- The port the socket was bound to.
- ZMQBindError
- if max_tries reached before successful bind
-
close
(linger=None)¶ Close the socket.
If linger is specified, LINGER sockopt will be set prior to closing.
This can be called to close the socket by hand. If this is not called, the socket will automatically be closed when it is garbage collected.
-
connect
(addr)¶ Connect to a remote 0MQ socket.
- addr : str
- The address string. This has the form ‘protocol://interface:port’, for example ‘tcp://127.0.0.1:5555’. Protocols supported are tcp, upd, pgm, inproc and ipc. If the address is unicode, it is encoded to utf-8 first.
-
disable_monitor
()¶ Shutdown the PAIR socket (created using get_monitor_socket) that is serving socket events.
New in version 14.4.
-
disconnect
(addr)¶ Disconnect from a remote 0MQ socket (undoes a call to connect).
New in version libzmq-3.2.
New in version 13.0.
- addr : str
- The address string. This has the form ‘protocol://interface:port’, for example ‘tcp://127.0.0.1:5555’. Protocols supported are tcp, upd, pgm, inproc and ipc. If the address is unicode, it is encoded to utf-8 first.
-
fileno
()¶ Return edge-triggered file descriptor for this socket.
This is a read-only edge-triggered file descriptor for both read and write events on this socket. It is important that all available events be consumed when an event is detected, otherwise the read event will not trigger again.
New in version 17.0.
-
get
(option)¶ Get the value of a socket option.
See the 0MQ API documentation for details on specific options.
- option : int
The option to get. Available values will depend on your version of libzmq. Examples include:
zmq.IDENTITY, HWM, LINGER, FD, EVENTS
- optval : int or bytes
- The value of the option as a bytestring or int.
-
get_hwm
()¶ Get the High Water Mark.
On libzmq ≥ 3, this gets SNDHWM if available, otherwise RCVHWM
-
get_monitor_socket
(events=None, addr=None)¶ Return a connected PAIR socket ready to receive the event notifications.
New in version libzmq-4.0.
New in version 14.0.
- events : int [default: ZMQ_EVENTS_ALL]
- The bitmask defining which events are wanted.
- addr : string [default: None]
- The optional endpoint for the monitoring sockets.
- socket : (PAIR)
- The socket is already connected and ready to receive messages.
-
get_string
(option, encoding='utf-8')¶ Get the value of a socket option.
See the 0MQ documentation for details on specific options.
- option : int
- The option to retrieve.
- optval : unicode string (unicode on py2, str on py3)
- The value of the option as a unicode string.
-
getsockopt
(option)¶ s.get(option)
Get the value of a socket option.
See the 0MQ API documentation for details on specific options.
- option : int
The option to get. Available values will depend on your version of libzmq. Examples include:
zmq.IDENTITY, HWM, LINGER, FD, EVENTS
- optval : int or bytes
- The value of the option as a bytestring or int.
-
getsockopt_string
(option, encoding='utf-8')¶ Get the value of a socket option.
See the 0MQ documentation for details on specific options.
- option : int
- The option to retrieve.
- optval : unicode string (unicode on py2, str on py3)
- The value of the option as a unicode string.
-
getsockopt_unicode
(option, encoding='utf-8')¶ Get the value of a socket option.
See the 0MQ documentation for details on specific options.
- option : int
- The option to retrieve.
- optval : unicode string (unicode on py2, str on py3)
- The value of the option as a unicode string.
-
hwm
¶ Get the High Water Mark.
On libzmq ≥ 3, this gets SNDHWM if available, otherwise RCVHWM
-
join
(group)¶ Join a RADIO-DISH group
Only for DISH sockets.
libzmq and pyzmq must have been built with ZMQ_BUILD_DRAFT_API
New in version 17.
-
leave
(group)¶ Leave a RADIO-DISH group
Only for DISH sockets.
libzmq and pyzmq must have been built with ZMQ_BUILD_DRAFT_API
New in version 17.
-
monitor
(addr, flags)¶ Start publishing socket events on inproc. See libzmq docs for zmq_monitor for details.
While this function is available from libzmq 3.2, pyzmq cannot parse monitor messages from libzmq prior to 4.0.
- addr : str
- The inproc url used for monitoring. Passing None as the addr will cause an existing socket monitor to be deregistered.
- events : int [default: zmq.EVENT_ALL]
- The zmq event bitmask for which events will be sent to the monitor.
-
poll
(timeout=None, flags=1)¶ Poll the socket for events. See
Poller
to wait for multiple sockets at once.- timeout : int [default: None]
- The timeout (in milliseconds) to wait for an event. If unspecified (or specified None), will wait forever for an event.
- flags : int [default: POLLIN]
- POLLIN, POLLOUT, or POLLIN|POLLOUT. The event flags to poll for.
- events : int
- The events that are ready and waiting, 0 if the timeout was reached with no events.
-
recv
(flags=0, copy=True, track=False) Receive a message.
With flags=NOBLOCK, this raises
ZMQError
if no messages have arrived; otherwise, this waits until a message arrives. SeePoller
for more general non-blocking I/O.- flags : int
- 0 or NOBLOCK.
- copy : bool
- Should the message be received in a copying or non-copying manner? If False a Frame object is returned, if True a string copy of message is returned.
- track : bool
- Should the message be tracked for notification that ZMQ has finished with it? (ignored if copy=True)
- msg : bytes or Frame
- The received message frame. If copy is False, then it will be a Frame, otherwise it will be bytes.
- ZMQError
- for any of the reasons zmq_msg_recv might fail (including if NOBLOCK is set and no new messages have arrived).
-
recv_json
(flags=0, **kwargs)¶ Receive a Python object as a message using json to serialize.
Keyword arguments are passed on to json.loads
- flags : int
- Any valid flags for
Socket.recv()
.
- obj : Python object
- The Python object that arrives as a message.
- ZMQError
- for any of the reasons
recv()
might fail
-
recv_multipart
(flags=0, copy=True, track=False)¶ Receive a multipart message as a list of bytes or Frame objects
- flags : int, optional
- Any valid flags for
Socket.recv()
. - copy : bool, optional
- Should the message frame(s) be received in a copying or non-copying manner? If False a Frame object is returned for each part, if True a copy of the bytes is made for each frame.
- track : bool, optional
- Should the message frame(s) be tracked for notification that ZMQ has finished with it? (ignored if copy=True)
- msg_parts : list
- A list of frames in the multipart message; either Frames or bytes, depending on copy.
- ZMQError
- for any of the reasons
recv()
might fail
-
recv_pyobj
(flags=0)¶ Receive a Python object as a message using pickle to serialize.
- flags : int
- Any valid flags for
Socket.recv()
.
- obj : Python object
- The Python object that arrives as a message.
- ZMQError
- for any of the reasons
recv()
might fail
-
recv_serialized
(deserialize, flags=0, copy=True)¶ Receive a message with a custom deserialization function.
New in version 17.
- deserialize : callable
- The deserialization function to use. deserialize will be called with one argument: the list of frames returned by recv_multipart() and can return any object.
- flags : int, optional
- Any valid flags for
Socket.recv()
. - copy : bool, optional
- Whether to recv bytes or Frame objects.
- obj : object
- The object returned by the deserialization function.
- ZMQError
- for any of the reasons
recv()
might fail
-
recv_string
(flags=0, encoding='utf-8')¶ Receive a unicode string, as sent by send_string.
- flags : int
- Any valid flags for
Socket.recv()
. - encoding : str [default: ‘utf-8’]
- The encoding to be used
- s : unicode string (unicode on py2, str on py3)
- The Python unicode string that arrives as encoded bytes.
- ZMQError
- for any of the reasons
recv()
might fail
-
recv_unicode
(flags=0, encoding='utf-8')¶ Receive a unicode string, as sent by send_string.
- flags : int
- Any valid flags for
Socket.recv()
. - encoding : str [default: ‘utf-8’]
- The encoding to be used
- s : unicode string (unicode on py2, str on py3)
- The Python unicode string that arrives as encoded bytes.
- ZMQError
- for any of the reasons
recv()
might fail
-
send
(msg, flags=0, copy=True, track=False) Send a single zmq message frame on this socket.
This queues the message to be sent by the IO thread at a later time.
With flags=NOBLOCK, this raises
ZMQError
if the queue is full; otherwise, this waits until space is available. SeePoller
for more general non-blocking I/O.- data : bytes, Frame, memoryview
- The content of the message. This can be any object that provides the Python buffer API (i.e. memoryview(data) can be called).
- flags : int
- 0, NOBLOCK, SNDMORE, or NOBLOCK|SNDMORE.
- copy : bool
- Should the message be sent in a copying or non-copying manner.
- track : bool
- Should the message be tracked for notification that ZMQ has finished with it? (ignored if copy=True)
- routing_id : int
- For use with SERVER sockets
- group : str
- For use with RADIO sockets
- None : if copy or not track
- None if message was sent, raises an exception otherwise.
- MessageTracker : if track and not copy
- a MessageTracker object, whose pending property will be True until the send is completed.
- TypeError
- If a unicode object is passed
- ValueError
- If track=True, but an untracked Frame is passed.
- ZMQError
- If the send does not succeed for any reason (including if NOBLOCK is set and the outgoing queue is full).
Changed in version 17.0: DRAFT support for routing_id and group arguments.
-
send_json
(obj, flags=0, **kwargs)¶ Send a Python object as a message using json to serialize.
Keyword arguments are passed on to json.dumps
- obj : Python object
- The Python object to send
- flags : int
- Any valid flags for
Socket.send()
-
send_multipart
(msg_parts, flags=0, copy=True, track=False)¶ Send a sequence of buffers as a multipart message.
The zmq.SNDMORE flag is added to all msg parts before the last.
- msg_parts : iterable
- A sequence of objects to send as a multipart message. Each element can be any sendable object (Frame, bytes, buffer-providers)
- flags : int, optional
- Any valid flags for
Socket.send()
. SNDMORE is added automatically for frames before the last. - copy : bool, optional
- Should the frame(s) be sent in a copying or non-copying manner. If copy=False, frames smaller than self.copy_threshold bytes will be copied anyway.
- track : bool, optional
- Should the frame(s) be tracked for notification that ZMQ has finished with it (ignored if copy=True).
None : if copy or not track MessageTracker : if track and not copy
a MessageTracker object, whose pending property will be True until the last send is completed.
-
send_pyobj
(obj, flags=0, protocol=2)¶ Send a Python object as a message using pickle to serialize.
- obj : Python object
- The Python object to send.
- flags : int
- Any valid flags for
Socket.send()
. - protocol : int
- The pickle protocol number to use. The default is pickle.DEFAULT_PROTOCOL where defined, and pickle.HIGHEST_PROTOCOL elsewhere.
-
send_serialized
(msg, serialize, flags=0, copy=True, **kwargs)¶ Send a message with a custom serialization function.
New in version 17.
msg : The message to be sent. Can be any object serializable by serialize. serialize : callable
The serialization function to use. serialize(msg) should return an iterable of sendable message frames (e.g. bytes objects), which will be passed to send_multipart.- flags : int, optional
- Any valid flags for
Socket.send()
. - copy : bool, optional
- Whether to copy the frames.
-
send_string
(u, flags=0, copy=True, encoding='utf-8')¶ Send a Python unicode string as a message with an encoding.
0MQ communicates with raw bytes, so you must encode/decode text (unicode on py2, str on py3) around 0MQ.
- u : Python unicode string (unicode on py2, str on py3)
- The unicode string to send.
- flags : int, optional
- Any valid flags for
Socket.send()
. - encoding : str [default: ‘utf-8’]
- The encoding to be used
-
send_unicode
(u, flags=0, copy=True, encoding='utf-8', **kwargs)¶ Send a Python unicode string as a message with an encoding.
0MQ communicates with raw bytes, so you must encode/decode text (unicode on py2, str on py3) around 0MQ.
- u : Python unicode string (unicode on py2, str on py3)
- The unicode string to send.
- flags : int, optional
- Any valid flags for
Socket.send()
. - encoding : str [default: ‘utf-8’]
- The encoding to be used
-
set
(option, optval)¶ Set socket options.
See the 0MQ API documentation for details on specific options.
- option : int
The option to set. Available values will depend on your version of libzmq. Examples include:
zmq.SUBSCRIBE, UNSUBSCRIBE, IDENTITY, HWM, LINGER, FD
- optval : int or bytes
- The value of the option to set.
Warning
All options other than zmq.SUBSCRIBE, zmq.UNSUBSCRIBE and zmq.LINGER only take effect for subsequent socket bind/connects.
-
set_hwm
(value)¶ Set the High Water Mark.
On libzmq ≥ 3, this sets both SNDHWM and RCVHWM
Warning
New values only take effect for subsequent socket bind/connects.
-
set_string
(option, optval, encoding='utf-8')¶ Set socket options with a unicode object.
This is simply a wrapper for setsockopt to protect from encoding ambiguity.
See the 0MQ documentation for details on specific options.
- option : int
- The name of the option to set. Can be any of: SUBSCRIBE, UNSUBSCRIBE, IDENTITY
- optval : unicode string (unicode on py2, str on py3)
- The value of the option to set.
- encoding : str
- The encoding to be used, default is utf8
-
setsockopt
()¶ s.set(option, optval)
Set socket options.
See the 0MQ API documentation for details on specific options.
- option : int
The option to set. Available values will depend on your version of libzmq. Examples include:
zmq.SUBSCRIBE, UNSUBSCRIBE, IDENTITY, HWM, LINGER, FD
- optval : int or bytes
- The value of the option to set.
Warning
All options other than zmq.SUBSCRIBE, zmq.UNSUBSCRIBE and zmq.LINGER only take effect for subsequent socket bind/connects.
-
setsockopt_string
(option, optval, encoding='utf-8')¶ Set socket options with a unicode object.
This is simply a wrapper for setsockopt to protect from encoding ambiguity.
See the 0MQ documentation for details on specific options.
- option : int
- The name of the option to set. Can be any of: SUBSCRIBE, UNSUBSCRIBE, IDENTITY
- optval : unicode string (unicode on py2, str on py3)
- The value of the option to set.
- encoding : str
- The encoding to be used, default is utf8
-
setsockopt_unicode
(option, optval, encoding='utf-8')¶ Set socket options with a unicode object.
This is simply a wrapper for setsockopt to protect from encoding ambiguity.
See the 0MQ documentation for details on specific options.
- option : int
- The name of the option to set. Can be any of: SUBSCRIBE, UNSUBSCRIBE, IDENTITY
- optval : unicode string (unicode on py2, str on py3)
- The value of the option to set.
- encoding : str
- The encoding to be used, default is utf8
-
classmethod
shadow
(address)¶ Shadow an existing libzmq socket
address is the integer address of the libzmq socket or an FFI pointer to it.
New in version 14.1.
-
subscribe
(topic)¶ Subscribe to a topic
Only for SUB sockets.
New in version 15.3.
-
unbind
(addr)¶ Unbind from an address (undoes a call to bind).
New in version libzmq-3.2.
New in version 13.0.
- addr : str
- The address string. This has the form ‘protocol://interface:port’, for example ‘tcp://127.0.0.1:5555’. Protocols supported are tcp, upd, pgm, inproc and ipc. If the address is unicode, it is encoded to utf-8 first.
-
underlying
¶ The address of the underlying libzmq socket
-
unsubscribe
(topic)¶ Unsubscribe from a topic
Only for SUB sockets.
New in version 15.3.
[1] | http://github.com/zeromq/pyzmq |
[2] | http://www.zeromq.com |
[3] | http://www.cython.org |