blob: bd49b1d36792fa9538bafa323c8f0a09c80e0878 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
# PUB Protocol
The {{i:_PUB_ protocol}}{{hi:protocol, _PUB_} is one half of a {{i:publisher}}/subscriber pattern.
In this pattern, a publisher sends data, which is broadcast to all
subscribers.
The subscribing applications only see the data to which
they have subscribed.
The _PUB_ protocol is the publisher side, and the
[_SUB_](sub.md) protocol is the subscriber side.
> [!NOTE]
> In this implementation, the publisher delivers all messages to all
> subscribers.
> The subscribers maintain their own subscriptions, and filter them locally.
> Thus, this pattern should not be used in an attempt to reduce bandwidth
> consumption.
The topics that subscribers subscribe to is just the first part of
the message body.
Applications should construct their messages accordingly.
## Socket Operations
The [`nng_pub0_open()`](../api/nng_pub_open.md) functions create a publisher socket.
This socket may be used to send messages, but is unable to receive them.
Attempts to receive messages will result in `NNG_ENOTSUP`.
## Protocol Versions
Only version 0 of this protocol is supported.
(At the time of writing, no other versions of this protocol have been defined.)
## Protocol Options
The _PUB_ protocol has no protocol-specific options.
## Protocol Headers
The _PUB_ protocol has no protocol-specific headers.
|