+# vim: expandtab ts=4 sw=4:
# ==================================================================================
# Copyright (c) 2019 Nokia
# Copyright (c) 2018-2019 AT&T Intellectual Property.
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
# 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_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):
"""
Refer to the rmr C documentation for rmr_alloc_msg
extern rmr_mbuf_t* rmr_alloc_msg(void* vctx, int size)
+
+ if payload is not None, attempts to set the payload
+ if gen_transaction_id is True, it generates and sets a transaction id
+ if mtype is not None, sets the sbuf's message type
+ if meid is not None, sets the sbuf's meid
+
"""
- 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 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
def rmr_free_msg(mbuf):
"""
Refer to the rmr C documentation for rmr_free_msg
- extern void rmr_free_msg( rmr_mbuf_t* mbuf )
+ extern void rmr_free_msg(rmr_mbuf_t* mbuf )
"""
if mbuf is not None:
_rmr_free_msg(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);
"""
- return _rmr_bytes2meid(ptr_mbuf, src, length)
+ return _rmr_bytes2meid(ptr_mbuf, byte_str, len(byte_str))
-# this is an alias to rmr_bytes2meid using familiar set/get terminoloigy
-rmr_set_meid = rmr_bytes2meid
-
# 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.
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.value.decode() # decode turns into a string
+ return buf.value
_rmr_get_src = rmr_c_lib.rmr_get_src
dict message summary
"""
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,
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)