oxmox
7063e2102e
git-subtree-dir: external/nng git-subtree-split: 29b73962b939a6fbbf6ea8d5d7680bb06d0eeb99
63 lines
1.9 KiB
Text
63 lines
1.9 KiB
Text
= nng_msg_insert(3)
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//
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// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
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// Copyright 2018 Capitar IT Group BV <info@capitar.com>
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//
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// This document is supplied under the terms of the MIT License, a
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// copy of which should be located in the distribution where this
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// file was obtained (LICENSE.txt). A copy of the license may also be
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// found online at https://opensource.org/licenses/MIT.
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//
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== NAME
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nng_msg_insert - prepend to message body
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== SYNOPSIS
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[source, c]
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----
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#include <nng/nng.h>
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int nng_msg_insert(nng_msg *msg, const void *val, size_t size);
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int nng_msg_insert_u16(nng_msg *msg, uint16_t val16);
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int nng_msg_insert_u32(nng_msg *msg, uint32_t val32);
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int nng_msg_insert_u64(nng_msg *msg, uint64_t val64);
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----
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== DESCRIPTION
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The `nng_msg_insert()` family of functions prepends data to
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the front of the body of message _msg_, reallocating it if necessary.
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The first function prepends _size_ bytes, copying them from _val_.
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The remaining functions prepend the specified value (such as _val32_)
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in network-byte order (big-endian).
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TIP: These functions make use of space pre-allocated in front of the
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message body if available, so they can often avoid performing any reallocation.
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Applications should use these instead of reallocating and copying message
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content themselves, in order to benefit from this capability.
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== RETURN VALUES
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These functions return 0 on success, and non-zero otherwise.
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== ERRORS
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[horizontal]
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`NNG_ENOMEM`:: Insufficient free memory exists.
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== SEE ALSO
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[.text-left]
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xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)],
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xref:nng_msg_append.3.adoc[nng_msg_append(3)],
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xref:nng_msg_body.3.adoc[nng_msg_body(3)],
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xref:nng_msg_chop.3.adoc[nng_msg_chop(3)],
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xref:nng_msg_free.3.adoc[nng_msg_free(3)],
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xref:nng_msg_len.3.adoc[nng_msg_len(3)],
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xref:nng_msg_realloc.3.adoc[nng_msg_realloc(3)],
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xref:nng_msg_trim.3.adoc[nng_msg_trim(3)],
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xref:nng_strerror.3.adoc[nng_strerror(3)],
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xref:nng_msg.5.adoc[nng_msg(5)],
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xref:nng.7.adoc[nng(7)]
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