2 Framework for python xapps
3 Framework here means Xapp classes that can be subclassed
5 # ==================================================================================
6 # Copyright (c) 2020 Nokia
7 # Copyright (c) 2020 AT&T Intellectual Property.
9 # Licensed under the Apache License, Version 2.0 (the "License");
10 # you may not use this file except in compliance with the License.
11 # You may obtain a copy of the License at
13 # http://www.apache.org/licenses/LICENSE-2.0
15 # Unless required by applicable law or agreed to in writing, software
16 # distributed under the License is distributed on an "AS IS" BASIS,
17 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 # See the License for the specific language governing permissions and
19 # limitations under the License.
20 # ==================================================================================
21 from threading import Thread
22 from ricxappframe import xapp_rmr
23 from ricxappframe.xapp_sdl import SDLWrapper
24 from ricxappframe.rmr import rmr
25 from mdclogpy import Logger
28 RIC_HEALTH_CHECK_REQ = 100
29 RIC_HEALTH_CHECK_RESP = 101
32 # Private base class; not for direct client use
37 Base xapp; not for client use directly
40 def __init__(self, rmr_port=4562, rmr_wait_for_ready=True, use_fake_sdl=False, post_init=None):
49 rmr_wait_for_ready: bool (optional)
50 if this is True, then init waits until rmr is ready to send, which includes having a valid routing file.
51 this can be set to False if the client only wants to *receive only*
53 use_fake_sdl: bool (optional)
54 if this is True, it uses dbaas' "fake dict backend" instead of Redis or other backends.
55 Set this to true when developing your xapp or during unit testing to completely avoid needing a dbaas running or any network at all
57 post_init: function (optional)
58 runs this user provided function after the base xapp is initialized
59 it's signature should be post_init(self)
61 # PUBLIC, can be used by xapps using self.(name):
62 self.logger = Logger(name=__name__)
64 # Start rmr rcv thread
65 self._rmr_loop = xapp_rmr.RmrLoop(port=rmr_port, wait_for_ready=rmr_wait_for_ready)
66 self._mrc = self._rmr_loop.mrc # for convenience
69 self._sdl = SDLWrapper(use_fake_sdl)
71 # run the optionally provided user post init
77 def rmr_get_messages(self):
79 returns a generator iterable over all current messages in the queue that have not yet been read by the client xapp
81 while not self._rmr_loop.rcv_queue.empty():
82 (summary, sbuf) = self._rmr_loop.rcv_queue.get()
85 def rmr_send(self, payload, mtype, retries=100):
87 Allocates a buffer, sets payload and mtype, and sends
95 retries: int (optional)
96 Number of times to retry at the application level before excepting RMRFailure
101 whether or not the send worked after retries attempts
103 sbuf = rmr.rmr_alloc_msg(vctx=self._mrc, size=len(payload), payload=payload, gen_transaction_id=True, mtype=mtype)
105 for _ in range(retries):
106 sbuf = rmr.rmr_send_msg(self._mrc, sbuf)
107 if sbuf.contents.state == 0:
114 def rmr_rts(self, sbuf, new_payload=None, new_mtype=None, retries=100):
116 Allows the xapp to return to sender, possibly adjusting the payload and message type before doing so
118 This does NOT free the sbuf for the caller as the caller may wish to perform multiple rts per buffer.
119 The client needs to free.
123 sbuf: ctypes c_void_p
124 Pointer to an rmr message buffer
125 new_payload: bytes (optional)
127 new_mtype: int (optional)
128 New message type (replaces the received message)
129 retries: int (optional)
130 Number of times to retry at the application level before excepting RMRFailure
135 whether or not the send worked after retries attempts
137 for _ in range(retries):
138 sbuf = rmr.rmr_rts_msg(self._mrc, sbuf, payload=new_payload, mtype=new_mtype)
139 if sbuf.contents.state == 0:
142 self.logger.info("RTS Failed! Summary: {}".format(rmr.message_summary(sbuf)))
145 def rmr_free(self, sbuf):
147 Free an rmr message buffer after use
149 Note: this does not need to be a class method, self is not used. However if we break it out as a function we need a home for it.
152 sbuf: ctypes c_void_p
153 Pointer to an rmr message buffer
155 rmr.rmr_free_msg(sbuf)
158 # NOTE, even though these are passthroughs, the seperate SDL wrapper is useful for other applications like A1.
159 # Therefore, we don't embed that SDLWrapper functionality here so that it can be instantiated on it's own.
161 def sdl_set(self, ns, key, value, usemsgpack=True):
172 if usemsgpack is True, value can be anything serializable by msgpack
173 if usemsgpack is False, value must be bytes
174 usemsgpack: boolean (optional)
175 determines whether the value is serialized using msgpack
177 self._sdl.set(ns, key, value, usemsgpack)
179 def sdl_get(self, ns, key, usemsgpack=True):
189 usemsgpack: boolean (optional)
190 if usemsgpack is True, the value is deserialized using msgpack
191 if usemsgpack is False, the value is returned as raw bytes
195 None (if not exist) or see above; depends on usemsgpack
197 return self._sdl.get(ns, key, usemsgpack)
199 def sdl_find_and_get(self, ns, prefix, usemsgpack=True):
201 get all k v pairs that start with prefix
211 usemsgpack: boolean (optional)
212 if usemsgpack is True, the value returned is a dict where each value has been deserialized using msgpack
213 if usemsgpack is False, the value returned is as a dict mapping keys to raw bytes
217 {} (if no keys match) or see above; depends on usemsgpack
219 return self._sdl.find_and_get(ns, prefix, usemsgpack)
221 def sdl_delete(self, ns, key):
232 self._sdl.delete(ns, key)
236 def healthcheck(self):
238 this needs to be understood how this is supposed to work
240 return self._rmr_loop.healthcheck() and self._sdl.healthcheck()
244 cleans up and stops the xapp rmr thread (currently)
245 This is critical for unit testing as pytest will never return if the thread is running.
247 TODO: can we register a ctrl-c handler so this gets called on ctrl-c? Because currently two ctrl-c are needed to stop
249 self._rmr_loop.stop()
252 # Public Classes to subclass (these subclass _BaseXapp)
255 class RMRXapp(_BaseXapp):
257 Represents an xapp that is purely driven by rmr messages (i.e., when messages are received, the xapp does something
258 When run is called, the xapp framework waits for rmr messages, and calls the client provided consume callback on every one
261 def __init__(self, default_handler, rmr_port=4562, rmr_wait_for_ready=True, use_fake_sdl=False, post_init=None):
265 default_handler: function
266 a function with the signature (summary, sbuf) to be called when a message of type message_type is received
268 the rmr message summary
269 sbuf: ctypes c_void_p
270 Pointer to an rmr message buffer. The user must call free on this when done.
272 post_init: function (optional)
273 optionally runs this function after the app initializes and before the run loop
274 it's signature should be post_init(self)
276 For the other parameters, see _BaseXapp
280 rmr_port=rmr_port, rmr_wait_for_ready=rmr_wait_for_ready, use_fake_sdl=use_fake_sdl, post_init=post_init
284 self._default_handler = default_handler
287 # used for thread control
288 self._keep_going = True
290 # register a default healthcheck handler
291 # this default checks that rmr is working and SDL is working
292 # the user can override this and register their own handler if they wish since the "last registered callback wins".
293 def handle_healthcheck(self, summary, sbuf):
294 ok = self.healthcheck()
295 payload = b"OK\n" if ok else b"ERROR [RMR or SDL is unhealthy]\n"
296 self.rmr_rts(sbuf, new_payload=payload, new_mtype=RIC_HEALTH_CHECK_RESP)
299 self.register_callback(handle_healthcheck, RIC_HEALTH_CHECK_REQ)
301 def register_callback(self, handler, message_type):
303 registers this xapp to call handler(summary, buf) when an rmr message is received of type message_type
308 a function with the signature (summary, sbuf) to be called when a message of type message_type is received
310 the rmr message summary
311 sbuf: ctypes c_void_p
312 Pointer to an rmr message buffer. The user must call free on this when done.
315 the message type to look for
317 Note if this method is called multiple times for a single message type, the "last one wins".
319 self._dispatch[message_type] = handler
321 def run(self, thread=False):
323 This function should be called when the client xapp is ready to wait for their handlers to be called on received messages
327 thread: bool (optional)
328 if thread is True, execution is returned to caller and the queue read loop is executed in a thread.
329 The thread can be stopped using .stop()
330 if False, execution is not returned and the framework loops
334 while self._keep_going:
335 if not self._rmr_loop.rcv_queue.empty():
336 (summary, sbuf) = self._rmr_loop.rcv_queue.get()
338 func = self._dispatch.get(summary["message type"], None)
340 func = self._default_handler
341 func(self, summary, sbuf)
344 Thread(target=loop).start()
350 stops the rmr xapp completely.
353 self.logger.debug("Stopping queue reading thread..")
354 self._keep_going = False
357 class Xapp(_BaseXapp):
359 Represents an xapp where the client provides a generic function to call, which is mostly likely a loop-forever loop
362 def __init__(self, entrypoint, rmr_port=4562, rmr_wait_for_ready=True, use_fake_sdl=False):
367 this function is called when the xapp runs; this is the user code
368 it's signature should be function(self)
370 For the other parameters, see _BaseXapp
373 super().__init__(rmr_port=rmr_port, rmr_wait_for_ready=rmr_wait_for_ready, use_fake_sdl=use_fake_sdl)
374 self._entrypoint = entrypoint
378 This function should be called when the client xapp is ready to start their code
380 self._entrypoint(self)
382 # there is no need for stop currently here (base has, and nothing special to do here)