+# vim: expandtab ts=4 sw=4:
# ==================================================================================
-# Copyright (c) 2019 Nokia
-# Copyright (c) 2018-2019 AT&T Intellectual Property.
+# 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.
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 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
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 initialisation of something (probably message) failed
+ RMR_ERR_INITFAILED 15 initialization of something (probably message) failed
"""
if cache:
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 = _get_constants()["RMR_MAX_RCV_BYTES"]
+
+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):
"""
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.
"""
- return _rmr_init(uproto_port, max_msg_size, flags)
+ 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_alloc_msg.restype = POINTER(rmr_mbuf_t)
-def rmr_alloc_msg(vctx, size):
+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
+
"""
- return _rmr_alloc_msg(vctx, size)
+ 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_rts_msg.restype = POINTER(rmr_mbuf_t)
-def rmr_rts_msg(vctx, ptr_mbuf):
+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_bytes2meid.restype = c_int
-def rmr_bytes2meid(ptr_mbuf, src, length):
+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
"""
- return _rmr_bytes2meid(ptr_mbuf, src, length)
+ 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, dest):
+def rmr_get_meid(ptr_mbuf):
"""
- Refer to the rmr C documentation for rmr_get_meid
- extern unsigned char* rmr_get_meid(rmr_mbuf_t* mbuf, unsigned char* dest);
+ 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
"""
- return _rmr_get_meid(ptr_mbuf, dest)
+ 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
dict:
dict message summary
"""
- if ptr_mbuf.contents.len > RMR_MAX_RCV_BYTES:
- return "Malformed message: message length is greater than the maximum possible"
-
- meid = get_meid(ptr_mbuf)
- if meid == "\000" * _get_constants().get("RMR_MAX_MEID", 32): # special case all nils
- meid = None
-
return {
- "payload": get_payload(ptr_mbuf),
+ "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,
"message state": ptr_mbuf.contents.state,
"message status": _state_to_status(ptr_mbuf.contents.state),
"payload max size": rmr_payload_size(ptr_mbuf),
- "meid": meid,
+ "meid": rmr_get_meid(ptr_mbuf),
"message source": get_src(ptr_mbuf),
"errno": ptr_mbuf.contents.tp_state,
}
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
- | In place method, no return
+ Generate a UUID and Set an rmr transaction id to it
Parameters
----------
ptr_mbuf: ctypes c_void_p
Pointer to an rmr message buffer
"""
- uu_id = uuid.uuid1().hex.encode("utf-8")
- sz = _get_constants().get("RMR_MAX_XID", 0)
- memmove(ptr_mbuf.contents.xaction, uu_id, sz)
+ set_transaction_id(ptr_mbuf, uuid.uuid1().hex.encode("utf-8"))
-def get_meid(ptr_mbuf):
+def set_transaction_id(ptr_mbuf, tid_bytes):
"""
- | Get the managed equipment ID (meid) from the message header.
- | This is a 32 byte field and RMr returns all 32 bytes which if the sender did not set will be garbage.
+ 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
-
- Returns
- -------
- string:
- meid
+ tid_bytes: bytes
+ bytes of the desired transaction id
"""
- sz = _get_constants().get("RMR_MAX_MEID", 64) # size for buffer to fill
- buf = create_string_buffer(sz)
- rmr_get_meid(ptr_mbuf, buf)
- return buf.raw.decode()
+ sz = _get_constants().get("RMR_MAX_XID", 0)
+ memmove(ptr_mbuf.contents.xaction, tid_bytes, sz)
def get_src(ptr_mbuf):
Returns
-------
string:
- meid
+ message source
"""
sz = _get_constants().get("RMR_MAX_SRC", 64) # size to fill
buf = create_string_buffer(sz)