# ==================================================================================
# 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.
# ==================================================================================
"""
Wraps all RMR functions, but does not have a reference to the shared library.
"""
import uuid
from ctypes import POINTER, Structure
from ctypes import c_int, c_char, c_char_p, c_void_p, memmove, cast, create_string_buffer
from ricxappframe.rmr.exceptions import BadBufferAllocation, MeidSizeOutOfRange, InitFailed
from ricxappframe.rmr.rmrclib.rmrclib import rmr_c_lib, get_constants, state_to_status
##############
# PRIVATE API
##############
def _get_rmr_constant(key: str, default=None):
"""
Gets the constant with the named key from the RMR C library.
Returns None if the value is not a simple type. This happens
during sphinx autodoc document generation, which mocks the
rmrclib package to work without the RMR shared object file,
and the response is something like this:
<class 'ricxappframe.rmr.rmrclib.rmrclib.get_constants.get'>
Workaround for https://github.com/sphinx-doc/sphinx/issues/7422
"""
val = get_constants().get(key, default)
return val if isinstance(val, (type(None), bool, bytes, float, int, str)) else None
# argtypes and restype are important:
# https://stackoverflow.com/questions/24377845/ctype-why-specify-argtypes
def _wrap_rmr_function(funcname, restype, argtypes):
"""
Simplify wrapping ctypes functions.
Parameters
----------
funcname: str
Name of library method
restype: class
Name of ctypes class; e.g., c_char_p
argtypes: list
List of ctypes classes; e.g., [ c_char_p, int ]
Returns
-------
_FuncPointer:
Pointer to C library function
"""
func = rmr_c_lib.__getattr__(funcname)
func.restype = restype
func.argtypes = argtypes
return func
##############
# PUBLIC API
##############
# Publish constants from RMR C-language header files for use by importers of this library.
# TODO: Are there others that will be useful?
#: Typical size message to receive; size is not limited
RMR_MAX_RCV_BYTES = _get_rmr_constant('RMR_MAX_RCV_BYTES')
#: Multi-threaded initialization flag
RMRFL_MTCALL = _get_rmr_constant('RMRFL_MTCALL', 0x02) # initialization flags
#: Empty flag
RMRFL_NONE = _get_rmr_constant('RMRFL_NONE', 0x0)
#: State constant for OK
RMR_OK = _get_rmr_constant('RMR_OK', 0x00)
#: State constant for no endpoint based on msg type
RMR_ERR_NOENDPT = _get_rmr_constant('RMR_ERR_NOENDPT')
#: State constant for retry
RMR_ERR_RETRY = _get_rmr_constant('RMR_ERR_RETRY')
#: State constant for timeout
RMR_ERR_TIMEOUT = _get_rmr_constant('RMR_ERR_TIMEOUT')
# Publish keys used in the message summary dict as constants
# message payload, bytes
RMR_MS_PAYLOAD = "payload"
# payload length, integer
RMR_MS_PAYLOAD_LEN = "payload length"
# message type, integer
RMR_MS_MSG_TYPE = "message type"
# subscription ID, integer
RMR_MS_SUB_ID = "subscription id"
# transaction ID, bytes
RMR_MS_TRN_ID = "transaction id"
# state of message processing, integer; e.g., 0
RMR_MS_MSG_STATE = "message state"
# state of message processing converted to string; e.g., RMR_OK
RMR_MS_MSG_STATUS = "message status"
# number of bytes usable in the payload, integer
RMR_MS_PAYLOAD_MAX = "payload max size"
# managed entity ID, bytes
RMR_MS_MEID = "meid"
# message source, string; e.g., host:port
RMR_MS_MSG_SOURCE = "message source"
# transport state, integer
RMR_MS_ERRNO = "errno"
[docs]class rmr_mbuf_t(Structure):
"""
Mirrors public members of type rmr_mbuf_t from RMR 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
| 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;
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.
"""
# re payload, according to the following the python bytes are already unsigned:
# https://bytes.com/topic/python/answers/695078-ctypes-unsigned-char
_fields_ = [
("state", c_int),
("mtype", c_int),
("len", c_int),
("payload", POINTER(c_char)),
("xaction", POINTER(c_char)),
("sub_id", c_int),
("tp_state", c_int),
]
_rmr_init = _wrap_rmr_function('rmr_init', c_void_p, [c_char_p, c_int, c_int])
[docs]def rmr_init(uproto_port: c_char_p, max_msg_size: int, flags: int) -> c_void_p:
"""
Prepares the environment for sending and receiving messages.
Refer to RMR C documentation for method::
extern void* rmr_init(char* uproto_port, int max_msg_size, int flags)
This function raises an exception if the returned context is None.
Parameters
----------
uproto_port: c_char_p
Pointer to bytes built from the port number as a string; e.g., b'4550'
max_msg_size: integer
Maximum message size to receive
flags: integer
RMR option flags
Returns
-------
c_void_p:
Pointer to RMR context
"""
mrc = _rmr_init(uproto_port, max_msg_size, flags)
if mrc is None:
raise InitFailed()
return mrc
_rmr_ready = _wrap_rmr_function('rmr_ready', c_int, [c_void_p])
[docs]def rmr_ready(vctx: c_void_p) -> int:
"""
Checks if a routing table has been received and installed.
Refer to RMR C documentation for method::
extern int rmr_ready(void* vctx)
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
Returns
-------
1 for yes, 0 for no
"""
return _rmr_ready(vctx)
_rmr_close = _wrap_rmr_function('rmr_close', None, [c_void_p])
[docs]def rmr_close(vctx: c_void_p):
"""
Closes the listen socket.
Refer to RMR C documentation for method::
extern void rmr_close(void* vctx)
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
Returns
-------
None
"""
_rmr_close(vctx)
_rmr_set_stimeout = _wrap_rmr_function('rmr_set_stimeout', c_int, [c_void_p, c_int])
[docs]def rmr_set_stimeout(vctx: c_void_p, rloops: int) -> int:
"""
Sets the configuration for how RMR will retry message send operations.
Refer to RMR C documentation for method::
extern int rmr_set_stimeout(void* vctx, int rloops)
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
rloops: int
Number of retry loops
Returns
-------
0 on success, -1 on failure
"""
return _rmr_set_stimeout(vctx, rloops)
_rmr_alloc_msg = _wrap_rmr_function('rmr_alloc_msg', POINTER(rmr_mbuf_t), [c_void_p, c_int])
[docs]def rmr_alloc_msg(vctx: c_void_p, size: int,
payload=None, gen_transaction_id=False, mtype=None,
meid=None, sub_id=None, fixed_transaction_id=None):
"""
Allocates and returns a buffer to write and send through the RMR library.
Refer to RMR C documentation for method::
extern rmr_mbuf_t* rmr_alloc_msg(void* vctx, int size)
Optionally populates the message from the remaining arguments.
TODO: on next API break, clean up transaction_id ugliness. Kept for now to preserve API.
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
size: int
How much space to allocate
payload: bytes
if not None, attempts to set the payload
gen_transaction_id: bool
if True, generates and sets a transaction ID.
Note, option fixed_transaction_id overrides this option
mtype: bytes
if not None, sets the sbuf's message type
meid: bytes
if not None, sets the sbuf's meid
sub_id: bytes
if not None, sets the sbuf's subscription id
fixed_transaction_id: bytes
if not None, used as the transaction ID.
Note, this overrides the option gen_transaction_id
Returns
-------
c_void_p:
Pointer to rmr_mbuf structure
"""
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 = _wrap_rmr_function('rmr_realloc_payload', POINTER(rmr_mbuf_t), [POINTER(rmr_mbuf_t), c_int, c_int, c_int])
[docs]def rmr_realloc_payload(ptr_mbuf: c_void_p, new_len: int, copy=False, clone=False):
"""
Allocates and returns a message buffer large enough for the new length.
Refer to RMR C documentation for method::
extern rmr_mbuf_t* rmr_realloc_payload(rmr_mbuf_t*, int, int, int)
Parameters
----------
ptr_mbuf: c_void_p
Pointer to rmr_mbuf structure
new_len: int
Length
copy: bool
Whether to copy the original paylod
clone: bool
Whether to clone the original buffer
Returns
-------
c_void_p:
Pointer to rmr_mbuf structure
"""
return _rmr_realloc_payload(ptr_mbuf, new_len, copy, clone)
_rmr_free_msg = _wrap_rmr_function('rmr_free_msg', None, [POINTER(rmr_mbuf_t)])
[docs]def rmr_free_msg(ptr_mbuf: c_void_p):
"""
Releases the message buffer.
Refer to RMR C documentation for method::
extern void rmr_free_msg(rmr_mbuf_t* mbuf )
Parameters
----------
ptr_mbuf: c_void_p
Pointer to rmr_mbuf structure
Returns
-------
None
"""
if ptr_mbuf is not None:
_rmr_free_msg(ptr_mbuf)
_rmr_payload_size = _wrap_rmr_function('rmr_payload_size', c_int, [POINTER(rmr_mbuf_t)])
[docs]def rmr_payload_size(ptr_mbuf: c_void_p) -> int:
"""
Gets the number of bytes available in the payload.
Refer to RMR C documentation for method::
extern int rmr_payload_size(rmr_mbuf_t* mbuf)
Parameters
----------
ptr_mbuf: c_void_p
Pointer to rmr_mbuf structure
Returns
-------
int:
Number of bytes available
"""
return _rmr_payload_size(ptr_mbuf)
_rmr_send_msg = _wrap_rmr_function('rmr_send_msg', POINTER(rmr_mbuf_t), [c_void_p, POINTER(rmr_mbuf_t)])
[docs]def rmr_send_msg(vctx: c_void_p, ptr_mbuf: POINTER(rmr_mbuf_t)) -> POINTER(rmr_mbuf_t):
"""
Sends the message according to the routing table and returns an empty buffer.
Refer to RMR C documentation for method::
extern rmr_mbuf_t* rmr_send_msg(void* vctx, rmr_mbuf_t* mbuf)
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
ptr_mbuf: c_void_p
Pointer to rmr_mbuf structure
Returns
-------
ctypes c_void_p:
Pointer to rmr_mbuf structure
"""
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 = _wrap_rmr_function('rmr_rcv_msg', POINTER(rmr_mbuf_t), [c_void_p, POINTER(rmr_mbuf_t)])
[docs]def rmr_rcv_msg(vctx: c_void_p, ptr_mbuf: POINTER(rmr_mbuf_t)) -> POINTER(rmr_mbuf_t):
"""
Waits for a message to arrive, and returns it.
Refer to RMR C documentation for method::
extern rmr_mbuf_t* rmr_rcv_msg(void* vctx, rmr_mbuf_t* old_mbuf)
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
ptr_mbuf: c_void_p
Pointer to rmr_mbuf structure
Returns
-------
ctypes c_void_p:
Pointer to rmr_mbuf structure
"""
return _rmr_rcv_msg(vctx, ptr_mbuf)
_rmr_torcv_msg = _wrap_rmr_function('rmr_torcv_msg', POINTER(rmr_mbuf_t), [c_void_p, POINTER(rmr_mbuf_t), c_int])
[docs]def rmr_torcv_msg(vctx: c_void_p, ptr_mbuf: POINTER(rmr_mbuf_t), ms_to: int) -> POINTER(rmr_mbuf_t):
"""
Waits up to the timeout value for a message to arrive, and returns it.
Refer to RMR C documentation for method::
extern rmr_mbuf_t* rmr_torcv_msg(void* vctx, rmr_mbuf_t* old_mbuf, int ms_to)
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
ptr_mbuf: c_void_p
Pointer to rmr_mbuf structure
ms_to: int
Time out value in milliseconds
Returns
-------
ctypes c_void_p:
Pointer to rmr_mbuf structure
"""
return _rmr_torcv_msg(vctx, ptr_mbuf, ms_to)
_rmr_rts_msg = _wrap_rmr_function('rmr_rts_msg', POINTER(rmr_mbuf_t), [c_void_p, POINTER(rmr_mbuf_t)])
[docs]def rmr_rts_msg(vctx: c_void_p, ptr_mbuf: POINTER(rmr_mbuf_t), payload=None, mtype=None) -> POINTER(rmr_mbuf_t):
"""
Sends a message to the originating endpoint and returns an empty buffer.
Refer to RMR C documentation for method::
extern rmr_mbuf_t* rmr_rts_msg(void* vctx, rmr_mbuf_t* mbuf)
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
Parameters
----------
vctx: ctypes c_void_p
Pointer to an RMR context
ptr_mbuf: ctypes c_void_p
Pointer to an RMR message buffer
payload: bytes
Payload
mtype: bytes
Message type
Returns
-------
ctypes c_void_p:
Pointer to rmr_mbuf structure
"""
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 = _wrap_rmr_function('rmr_call', POINTER(rmr_mbuf_t), [c_void_p, POINTER(rmr_mbuf_t)])
[docs]def rmr_call(vctx: c_void_p, ptr_mbuf: POINTER(rmr_mbuf_t)) -> POINTER(rmr_mbuf_t):
"""
Sends a message, waits for a response and returns it.
Refer to RMR C documentation for method::
extern rmr_mbuf_t* rmr_call(void* vctx, rmr_mbuf_t* mbuf)
Parameters
----------
ptr_mbuf: ctypes c_void_p
Pointer to an RMR message buffer
Returns
-------
ctypes c_void_p:
Pointer to rmr_mbuf structure
"""
return _rmr_call(vctx, ptr_mbuf)
_rmr_bytes2meid = _wrap_rmr_function('rmr_bytes2meid', c_int, [POINTER(rmr_mbuf_t), c_char_p, c_int])
[docs]def rmr_set_meid(ptr_mbuf: POINTER(rmr_mbuf_t), byte_str: bytes) -> int:
"""
Sets the managed entity field in the message and returns the number of bytes copied.
Refer to RMR C documentation for method::
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
Parameters
----------
ptr_mbuf: ctypes c_void_p
Pointer to rmr_mbuf structure
byte_tr: bytes
Managed entity ID value
Returns
-------
int:
number of bytes copied
"""
max_meid = _get_rmr_constant("RMR_MAX_MEID", 32)
if len(byte_str) >= max_meid:
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 = _wrap_rmr_function('rmr_get_meid', c_char_p, [POINTER(rmr_mbuf_t), c_char_p])
[docs]def rmr_get_meid(ptr_mbuf: POINTER(rmr_mbuf_t)) -> bytes:
"""
Gets the managed entity ID (meid) from the message header.
This is a python-friendly version of RMR C method::
extern unsigned char* rmr_get_meid(rmr_mbuf_t* mbuf, unsigned char* dest);
Parameters
----------
ptr_mbuf: ctypes c_void_p
Pointer to rmr_mbuf structure
Returns
-------
bytes:
Managed entity ID
"""
max_meid = _get_rmr_constant("RMR_MAX_MEID", 32) # size for buffer to fill
buf = create_string_buffer(max_meid)
_rmr_get_meid(ptr_mbuf, buf)
return buf.value
_rmr_get_src = _wrap_rmr_function('rmr_get_src', c_char_p, [POINTER(rmr_mbuf_t), c_char_p])
[docs]def rmr_get_src(ptr_mbuf: POINTER(rmr_mbuf_t), dest: c_char_p) -> c_char_p:
"""
Copies the message-source information to the buffer.
Refer to RMR C documentation for method::
extern unsigned char* rmr_get_src(rmr_mbuf_t* mbuf, unsigned char* dest);
Parameters
----------
ptr_mbuf: ctypes POINTER(rmr_mbuf_t)
Pointer to rmr_mbuf structure
dest: ctypes c_char_p
Pointer to a buffer to receive the message source
Returns
-------
string:
message-source information
"""
return _rmr_get_src(ptr_mbuf, dest)
_rmr_set_vlevel = _wrap_rmr_function('rmr_set_vlevel', None, [c_int])
[docs]def rmr_set_vlevel(new_level: c_int):
"""
Sets the verbosity level which determines the messages RMR writes to standard error.
Refer to RMR C documentation for method::
void rmr_set_vlevel( int new_level )
Parameters
----------
new_level: int
New logging verbosity level, an integer in the range 0 (none) to 5 (debug).
"""
_rmr_set_vlevel(new_level)
_rmr_wh_call = _wrap_rmr_function('rmr_wh_call', POINTER(rmr_mbuf_t), [c_void_p, c_int, POINTER(rmr_mbuf_t), c_int, c_int])
[docs]def rmr_wh_call(vctx: c_void_p, whid: c_int, ptr_mbuf: POINTER(rmr_mbuf_t), call_id: c_int, max_wait: c_int) -> POINTER(rmr_mbuf_t):
"""
Sends a message buffer (msg) using a wormhole ID (whid) and waits for a response.
Refer to RMR C documentation for method::
rmr_mbuf_t* rmr_wh_call( void* vctx, rmr_whid_t whid, rmr_mbuf_t* mbuf, int call_id, int max_wait )
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
whid: c_int
Wormhole ID returned by rmr_wh_open
ptr_mbuf: ctypes POINTER(rmr_mbuf_t)
Pointer to rmr_mbuf structure
call_id: c_int
number in the range of 2..255 to identify the caller
max_wait: c_int
number of milliseconds to wait for a reply
Returns
-------
ctypes c_void_p:
Pointer to rmr_mbuf structure
"""
return _rmr_wh_call(vctx, whid, ptr_mbuf, call_id, max_wait)
_rmr_wh_close = _wrap_rmr_function('rmr_close', None, [c_void_p, c_int])
[docs]def rmr_wh_close(vctx: c_void_p, whid: c_int):
"""
Closes the wormhole associated with the wormhole id.
Refer to RMR C documentation for method::
void rmr_close( void* vctx, rmr_whid_t whid )
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
whid: c_int
Wormhole ID returned by rmr_wh_open
"""
_rmr_wh_close(vctx, whid)
_rmr_wh_open = _wrap_rmr_function('rmr_wh_open', c_int, [c_void_p, c_char_p])
[docs]def rmr_wh_open(vctx: c_void_p, target: c_char_p) -> c_int:
"""
Creates a direct link for sending to another RMR based process.
Refer to RMR C documentation for method::
rmr_whid_t rmr_wh_open( void* vctx, char* target )
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
target: str
name/IP and port combination of the target process; e.g., "localhost:6123"
Returns
-------
c_int:
Wormhole ID
"""
return _rmr_wh_open(vctx, target)
_rmr_wh_send_msg = _wrap_rmr_function('rmr_wh_send_msg', POINTER(rmr_mbuf_t), [c_void_p, c_int, POINTER(rmr_mbuf_t)])
[docs]def rmr_wh_send_msg(vctx: c_void_p, whid: c_int, ptr_mbuf: POINTER(rmr_mbuf_t)) -> POINTER(rmr_mbuf_t):
"""
Sends a message buffer (msg) using a wormhole ID (whid).
Refer to RMR C documentation for method::
rmr_mbuf_t* rmr_wh_send_msg( void* vctx, rmr_whid_t id, rmr_mbuf_t* msg )
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
whid: c_int
Wormhole ID returned by rmr_wh_open
ptr_mbuf: ctypes POINTER(rmr_mbuf_t)
Pointer to rmr_mbuf structure
Returns
-------
ctypes POINTER(rmr_mbuf_t):
Pointer to rmr_mbuf structure
"""
return _rmr_wh_send_msg(vctx, whid, ptr_mbuf)
_rmr_wh_state = _wrap_rmr_function('rmr_wh_state', c_int, [c_void_p, c_int])
[docs]def rmr_wh_state(vctx: c_void_p, whid: c_int) -> c_int:
"""
Gets the state of the connection associated with the given wormhole (whid).
Refer to RMR C documentation for method::
int rmr_wh_state( void* vctx, rmr_whid_t whid )
Parameters
----------
vctx: ctypes c_void_p
Pointer to RMR context
whid: c_int
Wormhole ID returned by rmr_wh_open
Returns
-------
c_int:
State of the connection
"""
return _rmr_wh_state(vctx, whid, whid)
########################################################################################
# Methods that exist ONLY in rmr-python, and are not wrapped methods.
# These should have been in a separate module, but leaving here to prevent api breakage.
########################################################################################
[docs]def get_payload(ptr_mbuf: c_void_p) -> bytes:
"""
Gets the binary payload from the rmr_buf_t*.
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
length = ptr_mbuf.contents.len
char_arr = c_char * length
return char_arr(*ptr_mbuf.contents.payload[:length]).raw
[docs]def get_xaction(ptr_mbuf: c_void_p) -> bytes:
"""
Gets the transaction ID from the rmr_buf_t*.
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
max_xid = _get_rmr_constant("RMR_MAX_XID", 0)
return val[:max_xid]
[docs]def message_summary(ptr_mbuf: c_void_p) -> dict:
"""
Builds a dict with the contents of an RMR message.
Parameters
----------
ptr_mbuf: ctypes c_void_p
Pointer to an RMR message buffer
Returns
-------
dict:
Message content as key-value pairs; keys are defined as RMR_MS_* constants.
"""
return {
RMR_MS_PAYLOAD: get_payload(ptr_mbuf) if ptr_mbuf.contents.state == RMR_OK else None,
RMR_MS_PAYLOAD_LEN: ptr_mbuf.contents.len,
RMR_MS_MSG_TYPE: ptr_mbuf.contents.mtype,
RMR_MS_SUB_ID: ptr_mbuf.contents.sub_id,
RMR_MS_TRN_ID: get_xaction(ptr_mbuf),
RMR_MS_MSG_STATE: ptr_mbuf.contents.state,
RMR_MS_MSG_STATUS: state_to_status(ptr_mbuf.contents.state),
RMR_MS_PAYLOAD_MAX: rmr_payload_size(ptr_mbuf),
RMR_MS_MEID: rmr_get_meid(ptr_mbuf),
RMR_MS_MSG_SOURCE: get_src(ptr_mbuf),
RMR_MS_ERRNO: ptr_mbuf.contents.tp_state,
}
[docs]def set_payload_and_length(byte_str: bytes, ptr_mbuf: c_void_p):
"""
Sets an rmr payload and content length.
Parameters
----------
byte_str: bytes
the bytes to set the payload to
ptr_mbuf: ctypes c_void_p
Pointer to an rmr message buffer
Returns
-------
None
"""
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)
[docs]def generate_and_set_transaction_id(ptr_mbuf: c_void_p):
"""
Generates a UUID and sets the 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"))
[docs]def set_transaction_id(ptr_mbuf: c_void_p, tid_bytes: bytes):
"""
Sets 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
"""
max_xid = _get_rmr_constant("RMR_MAX_XID", 0)
memmove(ptr_mbuf.contents.xaction, tid_bytes, max_xid)
[docs]def get_src(ptr_mbuf: c_void_p) -> str:
"""
Gets the message source (likely host:port)
Parameters
----------
ptr_mbuf: ctypes c_void_p
Pointer to an rmr message buffer
Returns
-------
string:
message source
"""
max_src = _get_rmr_constant("RMR_MAX_SRC", 64) # size to fill
buf = create_string_buffer(max_src)
rmr_get_src(ptr_mbuf, buf)
return buf.value.decode()