64 lines
1.9 KiB
Text
64 lines
1.9 KiB
Text
|
= nng_msg_insert(3)
|
||
|
|
//
|
||
|
|
// Copyright 2020 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_insert - prepend to message body
|
||
|
|
|
||
|
|
== SYNOPSIS
|
||
|
|
|
||
|
|
[source, c]
|
||
|
|
----
|
||
|
|
#include <nng/nng.h>
|
||
|
|
|
||
|
|
int nng_msg_insert(nng_msg *msg, const void *val, size_t size);
|
||
|
|
int nng_msg_insert_u16(nng_msg *msg, uint16_t val16);
|
||
|
|
int nng_msg_insert_u32(nng_msg *msg, uint32_t val32);
|
||
|
|
int nng_msg_insert_u64(nng_msg *msg, uint64_t val64);
|
||
|
|
----
|
||
|
|
|
||
|
|
== DESCRIPTION
|
||
|
|
|
||
|
|
The `nng_msg_insert()` family of functions prepends data to
|
||
|
|
the front of the body of message _msg_, reallocating it if necessary.
|
||
|
|
The first function prepends _size_ bytes, copying them from _val_.
|
||
|
|
The remaining functions prepend the specified value (such as _val32_)
|
||
|
|
in network-byte order (big-endian).
|
||
|
|
|
||
|
|
TIP: These functions make use of space pre-allocated in front of the
|
||
|
|
message body if available, so they can often avoid performing any reallocation.
|
||
|
|
Applications should use these instead of reallocating and copying message
|
||
|
|
content themselves, in order to benefit from this capability.
|
||
|
|
|
||
|
|
== RETURN VALUES
|
||
|
|
|
||
|
|
These functions return 0 on success, and non-zero otherwise.
|
||
|
|
|
||
|
|
== ERRORS
|
||
|
|
|
||
|
|
[horizontal]
|
||
|
|
`NNG_ENOMEM`:: Insufficient free memory exists.
|
||
|
|
|
||
|
|
== SEE ALSO
|
||
|
|
|
||
|
|
[.text-left]
|
||
|
|
xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)],
|
||
|
|
xref:nng_msg_append.3.adoc[nng_msg_append(3)],
|
||
|
|
xref:nng_msg_body.3.adoc[nng_msg_body(3)],
|
||
|
|
xref:nng_msg_chop.3.adoc[nng_msg_chop(3)],
|
||
|
|
xref:nng_msg_free.3.adoc[nng_msg_free(3)],
|
||
|
|
xref:nng_msg_len.3.adoc[nng_msg_len(3)],
|
||
|
|
xref:nng_msg_realloc.3.adoc[nng_msg_realloc(3)],
|
||
|
|
xref:nng_msg_trim.3.adoc[nng_msg_trim(3)],
|
||
|
|
xref:nng_strerror.3.adoc[nng_strerror(3)],
|
||
|
|
xref:nng_msg.5.adoc[nng_msg(5)],
|
||
|
|
xref:nng.7.adoc[nng(7)]
|