This documentation is for version v1.7.3 of NNG, but the latest released version is v1.8.0. see the documentation for v1.8.0 for the most up-to-date information.

nng_msg_reserve(3)

NAME

nng_msg_reserve - reserve storage for a message

SYNOPSIS

#include <nng/nng.h>

int nng_msg_reserve(nng_msg *msg, size_t capacity);

DESCRIPTION

The nng_msg_reserve() function ensures a message has allocated enough storage to accommodate a body of the given length. This message attempts to avoid extra allocations, and will reuse the existing memory when possible.

Using this message before nng_msg_append() will prevent additional memory allocations until the message’s length exceeds the alotted capacity.
Pointers to message body and header content obtained prior to this function must not be in use, as the underlying memory used for the message may have changed, particularly if the message capacity is increasing.

RETURN VALUES

This function returns 0 on success, and non-zero otherwise.

ERRORS

NNG_ENOMEM

Insufficient free memory exists to reallocate a message.

SEE ALSO