3 .. This work is licensed under a Creative Commons Attribution 4.0 International License.
4 .. SPDX-License-Identifier: CC-BY-4.0
5 .. CAUTION: this document is generated from source in doc/src/rtd.
6 .. To make changes edit the source and recompile the document.
7 .. Do NOT make changes directly to .rst or .md files.
12 ============================================================================================
14 The RIC Message Router (RMR) is a library for peer-to-peer
15 communication. Applications use the library to send and
16 receive messages where the message routing and endpoint
17 selection is based on the message type rather than DNS host
18 name-IP port combinations.
20 This document contains information that developers need to
21 know to contribute to the RMR project.
24 --------------------------------------------------------------------------------------------
26 RMR is written in C, and thus a contributing developer to the
27 core library should have an excellent working knowledge of C.
28 There currently is one set of cross-languages bindings
29 supporting Python, and a developer wishing to contribute to
30 the bindings source should be familiar with Python (version
31 3.7+) and with the Python *ctypes* library.
34 --------------------------------------------------------------------------------------------
36 RMR is designed to provide an insulation layer between user
37 applications and the actual transport mechanism. Initially
38 RMR was built on top of the third-party library Nanosmg,
39 shortly after was ported to the third-party library NNG
40 (Nanomsg Next Generation), and then was ported to an
41 internally developed socket library called SI95. RMR presents
42 the same API to the user application regardless of the
43 underlying transport library, but the resulting output when
44 compiling RMR is always a transport-specific library. As an
45 example, librmr_nng.a is the library generated for use with
48 As such the library source is organised into multiple
54 Source in the common directory is agnostic to the
55 underlying transport mechanism (Nanomsg, NNG, SI95, ..),
56 and thus can be used when generating either library.
60 Source which is tightly coupled with the underlying
61 Nanomsg library. (Nanomsg has been deprecated, but the RMR
62 source remains as an example.)
66 Source which is tightly coupled with the underlying NNG
67 library. (NNG has been deprecated, but the RMR source
68 remains as an example.)
72 Source which is tightly coupled with the underlying SI95
77 Internal Function Exposure
78 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
80 The decision to limit as much as practical the exposure of
81 truly internal RMR functions was made, and as a result most
82 of the RMR functions carry a static label. In order to
83 modularise the code as much as possible, this means that the
84 primary module (e.g. rmr_nng.c) directly includes other RMR
85 modules, rather than depending on referencing the internal
86 functions during linking. While this is an infrequently used
87 approach, it does mean that there are very few functions
88 visible for the user application to reference, all of them
89 having the prefix rmr\_. This allows internal functions to
90 have shorter names while still being meaningful.
93 --------------------------------------------------------------------------------------------
95 There is a list of coding style guidelines in the top level
96 directory, and as such they are not expanded upon here. The
97 general practice is to follow the style when editing an
98 existing module, respect the author's choice where style
99 alternatives are not frowned upon. When creating new modules,
100 select a style that fits the guidelines and is easy for you
101 to work with. There are a few things that the RMR maintainers
102 insist on, but for the most part style is up to the creator
106 --------------------------------------------------------------------------------------------
108 RMR is constructed using CMake. While CMake's project
109 description can be more cumbersome than most typical
110 Makefiles, the tool provides convenience especially when it
111 comes to creating DEB/RPM packages.