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= nng_msg_alloc(3)
//
// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
//
// 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_msg - message
== SYNOPSIS
[source, c]
----
#include <nng/nng.h>
typedef struct nng_msg nng_msg;
----
== DESCRIPTION
An `nng_msg` represents a single ((message)) sent between Scalability Protocols
peers.
Messages internally have a ((body)), containining the application supplied
payload, and a ((header)), containing protocol specific routing and similar
related information.
TIP: Using the message-oriented functions in the <<nng.7#,_nng_>> API is
a good way to reduce the likelihood of data copies and improve application
performance.
Messages are allocated using the <<nng_msg_alloc.3#,`nng_msg_alloc()`>>
function, and are deallocated using the <<nng_msg_free.3#,`nng_msg_free`>>
function.
In addition there are other functions used to access message contents,
including adding data to either the beginning or end of the message,
automatic data conversion, and removing data from the beginning or end.
These functions are designed to try to avoid copying message contents
by making use of scratch areas at the beginning and end of the message.
== RETURN VALUES
This function returns 0 on success, and non-zero otherwise.
== ERRORS
`NNG_ENOMEM`:: Insufficient free memory exists to allocate a message.
== SEE ALSO
<<nng_aio_get_msg.3#,nng_aio_get_msg(3)>>,
<<nng_aio_set_msg.3#,nng_aio_set_msg(3)>>,
<<nng_msg_alloc.3#,nng_msg_alloc(3)>>,
<<nng_msg_body.3#,nng_msg_body(3)>>,
<<nng_msg_dup.3#,nng_msg_dup(3)>>,
<<nng_msg_free.3#,nng_msg_free(3)>>,
<<nng_msg_header.3#,nng_msg_header(3)>>,
<<nng_msg_header_len.3#,nng_msg_header_len(3)>>,
<<nng_msg_len.3#,nng_msg_len(3)>>,
<<nng_msg_realloc.3#,nng_msg_realloc(3)>>,
<<nng_recvmsg.3#,nng_recvmsg(3)>>,
<<nng_sendmsg.3#,nng_sendmsg(3)>>,
<<nng_strerror.3#,nng_strerror(3)>>,
<<nng.7#,nng(7)>>
|
