+# vim: expandtab ts=4 sw=4:
+# ==================================================================================
+# Copyright (c) 2019-2020 Nokia
+# Copyright (c) 2018-2020 AT&T Intellectual Property.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==================================================================================
+import uuid
+import json
+from ctypes import RTLD_GLOBAL, Structure, c_int, POINTER, c_char, c_char_p, c_void_p, memmove, cast
+from ctypes import CDLL
+from ctypes import create_string_buffer
+from ricxappframe.rmr.exceptions import BadBufferAllocation, MeidSizeOutOfRange, InitFailed
+
+# https://docs.python.org/3.7/library/ctypes.html
+# https://stackoverflow.com/questions/2327344/ctypes-loading-a-c-shared-library-that-has-dependencies/30845750#30845750
+# make sure you do a set -x LD_LIBRARY_PATH /usr/local/lib/;
+
+# even though we don't use these directly, they contain symbols we need
+rmr_c_lib = CDLL("librmr_si.so", mode=RTLD_GLOBAL)
+
+
+# Internal Helpers (not a part of public api)
+
+
+_rmr_const = rmr_c_lib.rmr_get_consts
+_rmr_const.argtypes = []
+_rmr_const.restype = c_char_p
+
+
+def _get_constants(cache={}):
+ """
+ Get or build needed constants from rmr
+ TODO: are there constants that end user applications need?
+ """
+ if cache:
+ return cache
+
+ js = _rmr_const() # read json string
+ cache = json.loads(str(js.decode())) # create constants value object as a hash
+ return cache
+
+
+def _get_mapping_dict(cache={}):
+ """
+ Get or build the state mapping dict
+
+ RMR_OK 0 state is good
+ RMR_ERR_BADARG 1 argument passd to function was unusable
+ RMR_ERR_NOENDPT 2 send/call could not find an endpoint based on msg type
+ RMR_ERR_EMPTY 3 msg received had no payload; attempt to send an empty message
+ RMR_ERR_NOHDR 4 message didn't contain a valid header
+ RMR_ERR_SENDFAILED 5 send failed; errno has nano reason
+ RMR_ERR_CALLFAILED 6 unable to send call() message
+ RMR_ERR_NOWHOPEN 7 no wormholes are open
+ RMR_ERR_WHID 8 wormhole id was invalid
+ RMR_ERR_OVERFLOW 9 operation would have busted through a buffer/field size
+ RMR_ERR_RETRY 10 request (send/call/rts) failed, but caller should retry (EAGAIN for wrappers)
+ RMR_ERR_RCVFAILED 11 receive failed (hard error)
+ RMR_ERR_TIMEOUT 12 message processing call timed out
+ RMR_ERR_UNSET 13 the message hasn't been populated with a transport buffer
+ RMR_ERR_TRUNC 14 received message likely truncated
+ RMR_ERR_INITFAILED 15 initialization of something (probably message) failed
+
+ """
+ if cache:
+ return cache
+
+ rmr_consts = _get_constants()
+ for key in rmr_consts: # build the state mapping dict
+ if key[:7] in ["RMR_ERR", "RMR_OK"]:
+ en = int(rmr_consts[key])
+ cache[en] = key
+
+ return cache
+
+
+def _state_to_status(stateno):
+ """
+ Convert a msg state to status
+
+ """
+ sdict = _get_mapping_dict()
+ return sdict.get(stateno, "UNKNOWN STATE")
+
+
+_RCONST = _get_constants()
+
+
+##############
+# PUBLIC API
+##############
+
+
+# These constants are directly usable by importers of this library
+# TODO: Are there others that will be useful?
+
+RMR_MAX_RCV_BYTES = _RCONST["RMR_MAX_RCV_BYTES"]
+RMRFL_MTCALL = _RCONST.get("RMRFL_MTCALL", 0x02) # initialization flags
+RMRFL_NONE = _RCONST.get("RMRFL_NONE", 0x0)
+RMR_OK = _RCONST["RMR_OK"] # useful state constants
+RMR_ERR_TIMEOUT = _RCONST["RMR_ERR_TIMEOUT"]
+RMR_ERR_RETRY = _RCONST["RMR_ERR_RETRY"]
+
+
+class rmr_mbuf_t(Structure):
+ """
+ Reimplementation of rmr_mbuf_t which is in an unaccessible header file (src/common/include/rmr.h)
+
+ | typedef struct {
+ | int state; // state of processing
+ | int mtype; // message type
+ | int len; // length of data in the payload (send or received)
+ | unsigned char* payload; // transported data
+ | unsigned char* xaction; // pointer to fixed length transaction id bytes
+ | int sub_id; // subscription id
+ | int tp_state; // transport state (a.k.a errno)
+ |
+ | these things are off limits to the user application
+ |
+ | void* tp_buf; // underlying transport allocated pointer (e.g. nng message)
+ | void* header; // internal message header (whole buffer: header+payload)
+ | unsigned char* id; // if we need an ID in the message separate from the xaction id
+ | int flags; // various MFL (private) flags as needed
+ | int alloc_len; // the length of the allocated space (hdr+payload)
+ | } rmr_mbuf_t;
+
+ We do not include the fields we are not supposed to mess with
+
+ RE PAYLOADs type below, see the documentation for c_char_p:
+ class ctypes.c_char_p
+ Represents the C char * datatype when it points to a zero-terminated string. For a general character pointer that may also point to binary data, POINTER(c_char) must be used. The constructor accepts an integer address, or a bytes object.
+ """
+
+ _fields_ = [
+ ("state", c_int),
+ ("mtype", c_int),
+ ("len", c_int),
+ (
+ "payload",
+ POINTER(c_char),
+ ), # according to th following the python bytes are already unsinged https://bytes.com/topic/python/answers/695078-ctypes-unsigned-char
+ ("xaction", POINTER(c_char)),
+ ("sub_id", c_int),
+ ("tp_state", c_int),
+ ]
+
+
+# argtypes and restype are important: https://stackoverflow.com/questions/24377845/ctype-why-specify-argtypes
+
+
+_rmr_init = rmr_c_lib.rmr_init
+_rmr_init.argtypes = [c_char_p, c_int, c_int]
+_rmr_init.restype = c_void_p
+
+
+def rmr_init(uproto_port, max_msg_size, flags):
+ """
+ Refer to rmr C documentation for rmr_init
+ extern void* rmr_init(char* uproto_port, int max_msg_size, int flags)
+
+ This python function checks that the context is not None and raises
+ an excption if it is.
+ """
+ mrc = _rmr_init(uproto_port, max_msg_size, flags)
+ if mrc is None:
+ raise InitFailed()
+ return mrc
+
+
+_rmr_ready = rmr_c_lib.rmr_ready
+_rmr_ready.argtypes = [c_void_p]
+_rmr_ready.restype = c_int
+
+
+def rmr_ready(vctx):
+ """
+ Refer to rmr C documentation for rmr_ready
+ extern int rmr_ready(void* vctx)
+ """
+ return _rmr_ready(vctx)
+
+
+_rmr_close = rmr_c_lib.rmr_close
+_rmr_close.argtypes = [c_void_p]
+
+
+def rmr_close(vctx):
+ """
+ Refer to rmr C documentation for rmr_close
+ extern void rmr_close(void* vctx)
+ """
+ return _rmr_close(vctx)
+
+
+_rmr_set_stimeout = rmr_c_lib.rmr_set_stimeout
+_rmr_set_stimeout.argtypes = [c_void_p, c_int]
+_rmr_set_stimeout.restype = c_int
+
+
+def rmr_set_stimeout(vctx, time):
+ """
+ Refer to the rmr C documentation for rmr_set_stimeout
+ extern int rmr_set_stimeout(void* vctx, int time)
+ """
+ return _rmr_set_stimeout(vctx, time)
+
+
+_rmr_alloc_msg = rmr_c_lib.rmr_alloc_msg
+_rmr_alloc_msg.argtypes = [c_void_p, c_int]
+_rmr_alloc_msg.restype = POINTER(rmr_mbuf_t)
+
+
+def rmr_alloc_msg(
+ vctx, size, payload=None, gen_transaction_id=False, mtype=None, meid=None, sub_id=None, fixed_transaction_id=None
+):
+ """
+ Refer to the rmr C documentation for rmr_alloc_msg
+ extern rmr_mbuf_t* rmr_alloc_msg(void* vctx, int size)
+ TODO: on next API break, clean up transaction_id ugliness. Kept for now to preserve API.
+
+ if payload is not None, attempts to set the payload
+ if gen_transaction_id is True, it generates and sets a transaction id. Note, fixed_transaction_id supersedes this option
+ if mtype is not None, sets the sbuf's message type
+ if meid is not None, sets the sbuf's meid
+ if sub_id is not None, sets the sbud's subscription id
+ if fixed_transaction_id is set, it deterministically sets the transaction_id. This overrides the option gen_transation_id
+
+ """
+ sbuf = _rmr_alloc_msg(vctx, size)
+ try:
+ # make sure the alloc worked
+ sbuf.contents
+
+ # set specified fields
+ if payload:
+ set_payload_and_length(payload, sbuf)
+
+ if fixed_transaction_id:
+ set_transaction_id(sbuf, fixed_transaction_id)
+ elif gen_transaction_id:
+ generate_and_set_transaction_id(sbuf)
+
+ if mtype:
+ sbuf.contents.mtype = mtype
+
+ if meid:
+ rmr_set_meid(sbuf, meid)
+
+ if sub_id:
+ sbuf.contents.sub_id = sub_id
+
+ return sbuf
+
+ except ValueError:
+ raise BadBufferAllocation
+
+
+_rmr_realloc_payload = rmr_c_lib.rmr_realloc_payload
+_rmr_realloc_payload.argtypes = [POINTER(rmr_mbuf_t), c_int, c_int, c_int] # new_len, copy, clone
+_rmr_realloc_payload.restype = POINTER(rmr_mbuf_t)
+
+
+def rmr_realloc_payload(ptr_mbuf, new_len, copy=False, clone=False):
+ """
+ Refer to the rmr C documentation for rmr_realloc_payload().
+ extern rmr_mbuf_t* rmr_realloc_payload(rmr_mbuf_t*, int, int, int)
+ """
+ return _rmr_realloc_payload(ptr_mbuf, new_len, copy, clone)
+
+
+_rmr_free_msg = rmr_c_lib.rmr_free_msg
+_rmr_free_msg.argtypes = [c_void_p]
+_rmr_free_msg.restype = None
+
+
+def rmr_free_msg(mbuf):
+ """
+ Refer to the rmr C documentation for rmr_free_msg
+ extern void rmr_free_msg(rmr_mbuf_t* mbuf )
+ """
+ if mbuf is not None:
+ _rmr_free_msg(mbuf)
+
+
+_rmr_payload_size = rmr_c_lib.rmr_payload_size
+_rmr_payload_size.argtypes = [POINTER(rmr_mbuf_t)]
+_rmr_payload_size.restype = c_int
+
+
+def rmr_payload_size(ptr_mbuf):
+ """
+ Refer to the rmr C documentation for rmr_payload_size
+ extern int rmr_payload_size(rmr_mbuf_t* msg)
+ """
+ return _rmr_payload_size(ptr_mbuf)
+
+
+"""
+The following functions all seem to have the same interface
+"""
+
+_rmr_send_msg = rmr_c_lib.rmr_send_msg
+_rmr_send_msg.argtypes = [c_void_p, POINTER(rmr_mbuf_t)]
+_rmr_send_msg.restype = POINTER(rmr_mbuf_t)
+
+
+def rmr_send_msg(vctx, ptr_mbuf):
+ """
+ Refer to the rmr C documentation for rmr_send_msg
+ extern rmr_mbuf_t* rmr_send_msg(void* vctx, rmr_mbuf_t* msg)
+ """
+ return _rmr_send_msg(vctx, ptr_mbuf)
+
+
+# TODO: the old message (Send param) is actually optional, but I don't know how to specify that in Ctypes.
+_rmr_rcv_msg = rmr_c_lib.rmr_rcv_msg
+_rmr_rcv_msg.argtypes = [c_void_p, POINTER(rmr_mbuf_t)]
+_rmr_rcv_msg.restype = POINTER(rmr_mbuf_t)
+
+
+def rmr_rcv_msg(vctx, ptr_mbuf):
+ """
+ Refer to the rmr C documentation for rmr_rcv_msg
+ extern rmr_mbuf_t* rmr_rcv_msg(void* vctx, rmr_mbuf_t* old_msg)
+ """
+ return _rmr_rcv_msg(vctx, ptr_mbuf)
+
+
+_rmr_torcv_msg = rmr_c_lib.rmr_torcv_msg
+_rmr_torcv_msg.argtypes = [c_void_p, POINTER(rmr_mbuf_t), c_int]
+_rmr_torcv_msg.restype = POINTER(rmr_mbuf_t)
+
+
+def rmr_torcv_msg(vctx, ptr_mbuf, ms_to):
+ """
+ Refer to the rmr C documentation for rmr_torcv_msg
+ extern rmr_mbuf_t* rmr_torcv_msg(void* vctx, rmr_mbuf_t* old_msg, int ms_to)
+ """
+ return _rmr_torcv_msg(vctx, ptr_mbuf, ms_to)
+
+
+_rmr_rts_msg = rmr_c_lib.rmr_rts_msg
+_rmr_rts_msg.argtypes = [c_void_p, POINTER(rmr_mbuf_t)]
+_rmr_rts_msg.restype = POINTER(rmr_mbuf_t)
+
+
+def rmr_rts_msg(vctx, ptr_mbuf, payload=None, mtype=None):
+ """
+ Refer to the rmr C documentation for rmr_rts_msg
+ extern rmr_mbuf_t* rmr_rts_msg(void* vctx, rmr_mbuf_t* msg)
+
+ additional features beyond c-rmr:
+ if payload is not None, attempts to set the payload
+ if mtype is not None, sets the sbuf's message type
+ """
+
+ if payload:
+ set_payload_and_length(payload, ptr_mbuf)
+
+ if mtype:
+ ptr_mbuf.contents.mtype = mtype
+
+ return _rmr_rts_msg(vctx, ptr_mbuf)
+
+
+_rmr_call = rmr_c_lib.rmr_call
+_rmr_call.argtypes = [c_void_p, POINTER(rmr_mbuf_t)]
+_rmr_call.restype = POINTER(rmr_mbuf_t)
+
+
+def rmr_call(vctx, ptr_mbuf):
+ """
+ Refer to the rmr C documentation for rmr_call
+ extern rmr_mbuf_t* rmr_call(void* vctx, rmr_mbuf_t* msg)
+ """
+ return _rmr_call(vctx, ptr_mbuf)
+
+
+_rmr_bytes2meid = rmr_c_lib.rmr_bytes2meid
+_rmr_bytes2meid.argtypes = [POINTER(rmr_mbuf_t), c_char_p, c_int]
+_rmr_bytes2meid.restype = c_int
+
+
+def rmr_set_meid(ptr_mbuf, byte_str):
+ """
+ Refer to the rmr C documentation for rmr_bytes2meid
+ extern int rmr_bytes2meid(rmr_mbuf_t* mbuf, unsigned char const* src, int len);
+
+ Caution: the meid length supported in an RMR message is 32 bytes, but C applications
+ expect this to be a nil terminated string and thus only 31 bytes are actually available.
+
+ Raises: exceptions.MeidSizeOutOfRang
+ """
+ max = _get_constants().get("RMR_MAX_MEID", 32)
+ if len(byte_str) >= max:
+ raise MeidSizeOutOfRange
+
+ return _rmr_bytes2meid(ptr_mbuf, byte_str, len(byte_str))
+
+
+# CAUTION: Some of the C functions expect a mutable buffer to copy the bytes into;
+# if there is a get_* function below, use it to set up and return the
+# buffer properly.
+
+# extern unsigned char* rmr_get_meid(rmr_mbuf_t* mbuf, unsigned char* dest);
+# we don't provide direct access to this function (unless it is asked for) because it is not really useful to provide your own buffer.
+# Rather, rmr_get_meid does this for you, and just returns the string.
+_rmr_get_meid = rmr_c_lib.rmr_get_meid
+_rmr_get_meid.argtypes = [POINTER(rmr_mbuf_t), c_char_p]
+_rmr_get_meid.restype = c_char_p
+
+
+def rmr_get_meid(ptr_mbuf):
+ """
+ Get the managed equipment ID (meid) from the message header.
+
+ Parameters
+ ----------
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+
+ Returns
+ -------
+ string:
+ meid
+ """
+ sz = _get_constants().get("RMR_MAX_MEID", 32) # size for buffer to fill
+ buf = create_string_buffer(sz)
+ _rmr_get_meid(ptr_mbuf, buf)
+ return buf.value
+
+
+_rmr_get_src = rmr_c_lib.rmr_get_src
+_rmr_get_src.argtypes = [POINTER(rmr_mbuf_t), c_char_p]
+_rmr_get_src.restype = c_char_p
+
+
+def rmr_get_src(ptr_mbuf, dest):
+ """
+ Refer to the rmr C documentation for rmr_get_src
+ extern unsigned char* rmr_get_src(rmr_mbuf_t* mbuf, unsigned char* dest);
+ """
+ return _rmr_get_src(ptr_mbuf, dest)
+
+
+# Methods that exist ONLY in rmr-python, and are not wrapped methods
+# In hindsight, I wish i put these in a seperate module, but leaving this here to prevent api breakage.
+
+
+def get_payload(ptr_mbuf):
+ """
+ Given a rmr_buf_t*, get it's binary payload as a bytes object
+
+ Parameters
+ ----------
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+
+ Returns
+ -------
+ bytes:
+ the message payload
+ """
+ # Logic came from the answer here: https://stackoverflow.com/questions/55103298/python-ctypes-read-pointerc-char-in-python
+ sz = ptr_mbuf.contents.len
+ CharArr = c_char * sz
+ return CharArr(*ptr_mbuf.contents.payload[:sz]).raw
+
+
+def get_xaction(ptr_mbuf):
+ """
+ given a rmr_buf_t*, get it's transaction id
+
+ Parameters
+ ----------
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+
+ Returns
+ -------
+ bytes:
+ the transaction id
+ """
+ val = cast(ptr_mbuf.contents.xaction, c_char_p).value
+ sz = _get_constants().get("RMR_MAX_XID", 0)
+ return val[:sz]
+
+
+def message_summary(ptr_mbuf):
+ """
+ Returns a dict that contains the fields of a message
+
+ Parameters
+ ----------
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+
+ Returns
+ -------
+ dict:
+ dict message summary
+ """
+ return {
+ "payload": get_payload(ptr_mbuf) if ptr_mbuf.contents.state == RMR_OK else None,
+ "payload length": ptr_mbuf.contents.len,
+ "message type": ptr_mbuf.contents.mtype,
+ "subscription id": ptr_mbuf.contents.sub_id,
+ "transaction id": get_xaction(ptr_mbuf),
+ "message state": ptr_mbuf.contents.state,
+ "message status": _state_to_status(ptr_mbuf.contents.state),
+ "payload max size": rmr_payload_size(ptr_mbuf),
+ "meid": rmr_get_meid(ptr_mbuf),
+ "message source": get_src(ptr_mbuf),
+ "errno": ptr_mbuf.contents.tp_state,
+ }
+
+
+def set_payload_and_length(byte_str, ptr_mbuf):
+ """
+ | Set an rmr payload and content length
+ | In place method, no return
+
+ Parameters
+ ----------
+ byte_str: bytes
+ the bytes to set the payload to
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+ """
+ if rmr_payload_size(ptr_mbuf) < len(byte_str): # existing message payload too small
+ ptr_mbuf = rmr_realloc_payload(ptr_mbuf, len(byte_str), True)
+
+ memmove(ptr_mbuf.contents.payload, byte_str, len(byte_str))
+ ptr_mbuf.contents.len = len(byte_str)
+
+
+def generate_and_set_transaction_id(ptr_mbuf):
+ """
+ Generate a UUID and Set an rmr transaction id to it
+
+ Parameters
+ ----------
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+ """
+ set_transaction_id(ptr_mbuf, uuid.uuid1().hex.encode("utf-8"))
+
+
+def set_transaction_id(ptr_mbuf, tid_bytes):
+ """
+ Set an rmr transaction id
+ TODO: on next API break, merge these two functions. Not done now to preserve API.
+
+ Parameters
+ ----------
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+ tid_bytes: bytes
+ bytes of the desired transaction id
+ """
+ sz = _get_constants().get("RMR_MAX_XID", 0)
+ memmove(ptr_mbuf.contents.xaction, tid_bytes, sz)
+
+
+def get_src(ptr_mbuf):
+ """
+ Get the message source (likely host:port)
+
+ Parameters
+ ----------
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+
+ Returns
+ -------
+ string:
+ message source
+ """
+ sz = _get_constants().get("RMR_MAX_SRC", 64) # size to fill
+ buf = create_string_buffer(sz)
+ rmr_get_src(ptr_mbuf, buf)
+ return buf.value.decode()