nng_msg_reserve
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.
tip
Using this message before nng_msg_append()
will prevent additional memory allocations until the message’s length exceeds
the alotted capacity.
important
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
nng_msg_alloc, nng_msg_append, nng_msg_capacity, nng_msg_insert, nng_msg_len