rmr_c_lib = CDLL("librmr_nng.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
"""
Get or build the state mapping dict
- #define RMR_OK 0 // state is good
- #define RMR_ERR_BADARG 1 // argument passd to function was unusable
- #define RMR_ERR_NOENDPT 2 // send/call could not find an endpoint based on msg type
- #define RMR_ERR_EMPTY 3 // msg received had no payload; attempt to send an empty message
- #define RMR_ERR_NOHDR 4 // message didn't contain a valid header
- #define RMR_ERR_SENDFAILED 5 // send failed; errno has nano reason
- #define RMR_ERR_CALLFAILED 6 // unable to send call() message
- #define RMR_ERR_NOWHOPEN 7 // no wormholes are open
- #define RMR_ERR_WHID 8 // wormhole id was invalid
- #define RMR_ERR_OVERFLOW 9 // operation would have busted through a buffer/field size
- #define RMR_ERR_RETRY 10 // request (send/call/rts) failed, but caller should retry (EAGAIN for wrappers)
- #define RMR_ERR_RCVFAILED 11 // receive failed (hard error)
- #define RMR_ERR_TIMEOUT 12 // message processing call timed out
- #define RMR_ERR_UNSET 13 // the message hasn't been populated with a transport buffer
- #define RMR_ERR_TRUNC 14 // received message likely truncated
- #define RMR_ERR_INITFAILED 15 // initialisation of something (probably message) failed
+ 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 initialisation of something (probably message) failed
"""
if cache:
"""
Convert a msg state to status
- Parameters
- ----------
- stateno: int
- the state of the rmr message buffer
-
- Returns
- -------
- string
- the cooresponding message state
"""
sdict = _get_mapping_dict()
return sdict.get(stateno, "UNKNOWN STATE")
# 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"]
"""
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;
+ | 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:
+ 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_ = [
# argtypes and restype are important: https://stackoverflow.com/questions/24377845/ctype-why-specify-argtypes
-# extern void* rmr_init(char* uproto_port, int max_msg_size, int flags)
-rmr_init = rmr_c_lib.rmr_init
-rmr_init.argtypes = [c_char_p, c_int, c_int]
-rmr_init.restype = c_void_p
-
-
-# extern void rmr_close(void* vctx)
-rmr_close = rmr_c_lib.rmr_close
-rmr_close.argtypes = [c_void_p]
-# I don't think there's a restype needed here. THe return is simply "return" in the c lib
-
-# extern int rmr_ready(void* vctx)
-rmr_ready = rmr_c_lib.rmr_ready
-rmr_ready.argtypes = [c_void_p]
-rmr_ready.restype = c_int
-
-# extern int rmr_set_stimeout(void* vctx, int time)
-# RE "int time", from the C docs:
-# Set send timeout. The value time is assumed to be microseconds. The timeout is the
-# rough maximum amount of time that RMr will block on a send attempt when the underlying
-# mechnism indicates eagain or etimeedout. All other error conditions are reported
-# without this delay. Setting a timeout of 0 causes no retries to be attempted in
-# RMr code. Setting a timeout of 1 causes RMr to spin up to 10K retries before returning,
-# but without issuing a sleep. If timeout is > 1, then RMr will issue a sleep (1us)
-# after every 10K send attempts until the time value is reached. Retries are abandoned
-# if NNG returns anything other than NNG_AGAIN or NNG_TIMEDOUT.
-#
-# The default, if this function is not used, is 1; meaning that RMr will retry, but will
-# not enter a sleep. In all cases the caller should check the status in the message returned
-# after a send call.
-rmr_set_stimeout = rmr_c_lib.rmr_set_rtimeout
-rmr_set_stimeout.argtypes = [c_void_p, c_int]
-rmr_set_stimeout.restype = c_int
+_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)
+ """
+ return _rmr_init(uproto_port, max_msg_size, flags)
+
+
+_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
+
-# extern rmr_mbuf_t* rmr_alloc_msg(void* vctx, int size)
-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_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):
+ """
+ Refer to the rmr C documentation for rmr_alloc_msg
+ extern rmr_mbuf_t* rmr_alloc_msg(void* vctx, int size)
+ """
+ return rmr_alloc_msg(vctx, size)
-# extern int rmr_payload_size(rmr_mbuf_t* msg)
-rmr_payload_size = rmr_c_lib.rmr_payload_size
-rmr_payload_size.argtypes = [POINTER(rmr_mbuf_t)]
-rmr_payload_size.restype = c_int
+
+_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
"""
-# extern rmr_mbuf_t* rmr_send_msg(void* vctx, rmr_mbuf_t* msg)
-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)
+_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)
+
-# extern rmr_mbuf_t* rmr_rcv_msg(void* vctx, rmr_mbuf_t* old_msg)
# 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)
+_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)
-# extern rmr_mbuf_t* rmr_torcv_msg(void* vctx, rmr_mbuf_t* old_msg, int ms_to)
-# the version of receive for nng that has a timeout (give up after X ms)
-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)
-# extern rmr_mbuf_t* rmr_rts_msg(void* vctx, rmr_mbuf_t* msg)
-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)
+_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)
-# extern rmr_mbuf_t* rmr_call(void* vctx, rmr_mbuf_t* msg)
-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_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)
-# Header field interface
-# extern int rmr_bytes2meid(rmr_mbuf_t* mbuf, unsigned char const* src, int len);
-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_rts_msg(vctx, ptr_mbuf):
+ """
+ Refer to the rmr C documentation for rmr_rts_msg
+ extern rmr_mbuf_t* rmr_rts_msg(void* vctx, rmr_mbuf_t* msg)
+ """
+ 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_bytes2meid(ptr_mbuf, src, length):
+ """
+ Refer to the rmr C documentation for rmr_bytes2meid
+ extern int rmr_bytes2meid(rmr_mbuf_t* mbuf, unsigned char const* src, int len);
+ """
+ return _rmr_bytes2meid(ptr_mbuf, src, length)
# 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);
-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
-# extern unsigned char* rmr_get_src(rmr_mbuf_t* mbuf, unsigned char* dest);
-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
+_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):
+ """
+ Refer to the rmr C documentation for rmr_get_meid
+ extern unsigned char* rmr_get_meid(rmr_mbuf_t* mbuf, unsigned char* dest);
+ """
+ return _rmr_get_meid(ptr_mbuf, dest)
-# GET Methods
+_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 get_payload(ptr_to_rmr_buf_t):
+def rmr_get_src(ptr_mbuf, dest):
"""
- given a rmr_buf_t*, get it's binary payload as a bytes object
- this magical function came from the answer here: https://stackoverflow.com/questions/55103298/python-ctypes-read-pointerc-char-in-python
+ Refer to the rmr C documentation for rmr_get_src
+ extern unsigned char* rmr_get_src(rmr_mbuf_t* mbuf, unsigned char* dest);
"""
- sz = ptr_to_rmr_buf_t.contents.len
+ 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_to_rmr_buf_t.contents.payload[:sz]).raw
+ return CharArr(*ptr_mbuf.contents.payload[:sz]).raw
-def get_xaction(ptr_to_rmr_buf_t):
+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_to_rmr_buf_t.contents.xaction, c_char_p).value
+ 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_to_rmr_buf_t):
+def message_summary(ptr_mbuf):
"""
- Used for debugging mostly: returns a dict that contains the fields of a message
+ 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
"""
- if ptr_to_rmr_buf_t.contents.len > RMR_MAX_RCV_BYTES:
+ if ptr_mbuf.contents.len > RMR_MAX_RCV_BYTES:
return "Malformed message: message length is greater than the maximum possible"
- meid = get_meid(ptr_to_rmr_buf_t)
+ 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_to_rmr_buf_t),
- "payload length": ptr_to_rmr_buf_t.contents.len,
- "message type": ptr_to_rmr_buf_t.contents.mtype,
- "subscription id": ptr_to_rmr_buf_t.contents.sub_id,
- "transaction id": get_xaction(ptr_to_rmr_buf_t),
- "message state": ptr_to_rmr_buf_t.contents.state,
- "message status": _state_to_status(ptr_to_rmr_buf_t.contents.state),
- "payload max size": rmr_payload_size(ptr_to_rmr_buf_t),
+ "payload": get_payload(ptr_mbuf),
+ "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": meid,
- "message source": get_src(ptr_to_rmr_buf_t),
- "errno": ptr_to_rmr_buf_t.contents.tp_state,
+ "message source": get_src(ptr_mbuf),
+ "errno": ptr_mbuf.contents.tp_state,
}
-def set_payload_and_length(byte_str, ptr_to_rmr_buf_t):
+def set_payload_and_length(byte_str, ptr_mbuf):
"""
- use memmove to set the rmr_buf_t payload and content length
+ | 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
"""
- memmove(ptr_to_rmr_buf_t.contents.payload, byte_str, len(byte_str))
- ptr_to_rmr_buf_t.contents.len = len(byte_str)
+ memmove(ptr_mbuf.contents.payload, byte_str, len(byte_str))
+ ptr_mbuf.contents.len = len(byte_str)
-def generate_and_set_transaction_id(ptr_to_rmr_buf_t):
+def generate_and_set_transaction_id(ptr_mbuf):
"""
- use memmove to set the rmr_buf_t xaction
+ | Generate a UUID and Set an rmr transaction id to it
+ | In place method, no return
+
+ 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_to_rmr_buf_t.contents.xaction, uu_id, sz)
+ memmove(ptr_mbuf.contents.xaction, uu_id, sz)
-def get_meid(mbuf):
+def get_meid(ptr_mbuf):
"""
- Suss out 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.
+ | 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.
+
+ Parameters
+ ----------
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+
+ Returns
+ -------
+ string:
+ meid
"""
sz = _get_constants().get("RMR_MAX_MEID", 64) # size for buffer to fill
buf = create_string_buffer(sz)
- rmr_get_meid(mbuf, buf)
+ rmr_get_meid(ptr_mbuf, buf)
return buf.raw.decode()
-def get_src(mbuf):
+def get_src(ptr_mbuf):
"""
- Suss out the message source information (likely host:port).
+ Get the message source (likely host:port)
+
+ Parameters
+ ----------
+ ptr_mbuf: ctypes c_void_p
+ Pointer to an rmr message buffer
+
+ Returns
+ -------
+ string:
+ meid
"""
sz = _get_constants().get("RMR_MAX_SRC", 64) # size to fill
buf = create_string_buffer(sz)
- rmr_get_src(mbuf, buf)
+ rmr_get_src(ptr_mbuf, buf)
return buf.value.decode()