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
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
---
version: v1.3.2
layout: manpage_v2
---
<h1>nng_msg_insert(3)</h1>
<div class="sect1">
<h2 id="_name">NAME</h2>
<div class="sectionbody">
<div class="paragraph">
<p>nng_msg_insert - prepend to message body</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_synopsis">SYNOPSIS</h2>
<div class="sectionbody">
<div class="listingblock">
<div class="content">
<pre class="pygments highlight"><code data-lang="c"><span class="tok-cp">#include</span> <span class="tok-cpf"><nng/nng.h></span><span class="tok-cp">
</span><span class="tok-cp"></span>
<span class="tok-kt">int</span> <span class="tok-nf">nng_msg_insert</span><span class="tok-p">(</span><span class="tok-n">nng_msg</span> <span class="tok-o">*</span><span class="tok-n">msg</span><span class="tok-p">,</span> <span class="tok-k">const</span> <span class="tok-kt">void</span> <span class="tok-o">*</span><span class="tok-n">val</span><span class="tok-p">,</span> <span class="tok-n">size_t</span> <span class="tok-n">size</span><span class="tok-p">);</span>
<span class="tok-kt">int</span> <span class="tok-nf">nng_msg_insert_u16</span><span class="tok-p">(</span><span class="tok-n">nng_msg</span> <span class="tok-o">*</span><span class="tok-n">msg</span><span class="tok-p">,</span> <span class="tok-n">uint16_t</span> <span class="tok-n">val16</span><span class="tok-p">);</span>
<span class="tok-kt">int</span> <span class="tok-nf">nng_msg_insert_u32</span><span class="tok-p">(</span><span class="tok-n">nng_msg</span> <span class="tok-o">*</span><span class="tok-n">msg</span><span class="tok-p">,</span> <span class="tok-n">uint32_t</span> <span class="tok-n">val32</span><span class="tok-p">);</span>
<span class="tok-kt">int</span> <span class="tok-nf">nng_msg_insert_u64</span><span class="tok-p">(</span><span class="tok-n">nng_msg</span> <span class="tok-o">*</span><span class="tok-n">msg</span><span class="tok-p">,</span> <span class="tok-n">uint64_t</span> <span class="tok-n">val64</span><span class="tok-p">);</span></code></pre>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_description">DESCRIPTION</h2>
<div class="sectionbody">
<div class="paragraph">
<p>The <code>nng_msg_insert()</code> family of functions prepends data to
the front of the body of message <em>msg</em>, reallocating it if necessary.
The first function prepends <em>size</em> bytes, copying them from <em>val</em>.
The remaining functions prepend the specified value (such as <em>val32</em>)
in network-byte order (big-endian).</p>
</div>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
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.
</td>
</tr>
</table>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_return_values">RETURN VALUES</h2>
<div class="sectionbody">
<div class="paragraph">
<p>These functions return 0 on success, and non-zero otherwise.</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_errors">ERRORS</h2>
<div class="sectionbody">
<div class="hdlist">
<table>
<tr>
<td class="hdlist1">
<code>NNG_ENOMEM</code>
</td>
<td class="hdlist2">
<p>Insufficient free memory exists.</p>
</td>
</tr>
</table>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_see_also">SEE ALSO</h2>
<div class="sectionbody">
<div class="paragraph text-left">
<p><a href="nng_msg_alloc.3.html">nng_msg_alloc(3)</a>,
<a href="nng_msg_append.3.html">nng_msg_append(3)</a>,
<a href="nng_msg_body.3.html">nng_msg_body(3)</a>,
<a href="nng_msg_chop.3.html">nng_msg_chop(3)</a>,
<a href="nng_msg_free.3.html">nng_msg_free(3)</a>,
<a href="nng_msg_len.3.html">nng_msg_len(3)</a>,
<a href="nng_msg_realloc.3.html">nng_msg_realloc(3)</a>,
<a href="nng_msg_trim.3.html">nng_msg_trim(3)</a>,
<a href="nng_strerror.3.html">nng_strerror(3)</a>,
<a href="nng_msg.5.html">nng_msg(5)</a>,
<a href="nng.7.html">nng(7)</a></p>
</div>
</div>
</div>
|
