From 98f23e10cc1d65da6a7f6c7e4f5665d7afc27a86 Mon Sep 17 00:00:00 2001 From: Garrett D'Amore Date: Thu, 15 Mar 2018 08:40:17 -0700 Subject: fixes #286 nng_pair0_open (and all others) need man page fixes #279 consider restructuring man sections This represents a rather significant rework, and major editing effort, for the entire set of manual pages. All of the pages now have a section number in their filename; this assists in some other tooling, particularly ebook generation as every link needs to be programmatically modified when combined into an ebook. Section 5 is introduced, and populated with pages for the main types, and all options are now documented. Numerous errors have been corrected, including rewriting certain portions such as the header section of the surveyor protocol. Much work has been done to facilitate index generation, although certainly more work remains here. Every internal link within these pages now resolves; there are no more dead links. (This is required to generate Kindle format books.) --- docs/man/nng_sub.7.adoc | 86 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 docs/man/nng_sub.7.adoc (limited to 'docs/man/nng_sub.7.adoc') diff --git a/docs/man/nng_sub.7.adoc b/docs/man/nng_sub.7.adoc new file mode 100644 index 00000000..f222327d --- /dev/null +++ b/docs/man/nng_sub.7.adoc @@ -0,0 +1,86 @@ += nng_sub(7) +// +// Copyright 2018 Staysail Systems, Inc. +// Copyright 2018 Capitar IT Group BV +// +// This document is supplied under the terms of the MIT License, a +// copy of which should be located in the distribution where this +// file was obtained (LICENSE.txt). A copy of the license may also be +// found online at https://opensource.org/licenses/MIT. +// + +== NAME + +nng_sub - subscriber protocol + +== SYNOPSIS + +[source,c] +---- +#include +#include + +int nng_sub0_open(nng_socket *s); +---- + +== DESCRIPTION + +(((protocol, _sub_))) +The ((_sub_ protocol)) is one half of a 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 _sub_ protocol is the subscriber side, and the +<> protocol is the publisher 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 <> call creates a subscriber socket. +This socket may be used to receive messages, but is unable to send them. +Attempts to send 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 following protocol-specific options are available. + +((`NNG_OPT_SUB_SUBSCRIBE`))(((subscribe))):: + + This option registers a topic that the subscriber is interested in. + The option is write-only, and takes an array of bytes, of arbitrary size. + Each incoming message is checked against the list of subscribed topics. + If the body begins with the entire set of bytes in the topic, then the + message is accepted. If no topic matches, then the message is + discarded. ++ +TIP: To receive all messages, an empty topic (zero length) can be used. + +((`NNG_OPT_SUB_UNSUBSCRIBE`)):: + + This option, also read-only, removes a topic from the subscription list. + Note that if the topic was not previously subscribed to with + `NNG_OPT_SUB_SUBSCRIBE` then an `NNG_ENOENT` error will result. + +=== Protocol Headers + +The _sub_ protocol has no protocol-specific headers. + +== SEE ALSO + +<>, +<>, +<> -- cgit v1.2.3-70-g09d2