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NNG_STATS_GET(3) NNG Reference Manual NNG_STATS_GET(3)

NAME

nng_stats_get - get statistics snapshot

SYNOPSIS

#include <nng/nng.h>
typedef struct nng_stat nng_stat;
int nng_stats_get(nng_stat **statsp)

DESCRIPTION

The nng_stat_get() function attempts to obtain a snapshot of all the various diagnostic statistics that are present in the system.


Note

The process of collecting statistics is designed to have minimal
impact on the system, but there is still some impact.

The statistics are organized as a tree, rooted with a parent statistic of type NNG_STAT_SCOPE that carries no value, and which has an empty name. This parent statistic is returned through the statsp pointer.

The nng_stat_child() and nng_stat_next() function can be used to iterate over the the tree.

When no longer needed, the statistics can be freed with the nng_stats_free() function, but that function must be called only with the root statistic that is returned through the statsp pointer.


Note

The values of individual statistics are guaranteed to be atomic,
but due the way statistics are collected there can be discrepancies between them at certain times. For example, statistics counting bytes and messages received may not reflect the same number of messages, depending on when the snapshot is taken. This potential inconsistency arises as a result of optimizations to minimize the impact of statistics on actual operations.


Note

The names, values, and semantics of statistics provided may change
from release to release. These are provided for informational and debugging use only, and applications should not rely on the presence, names, or meanings of any individual statistics.

RETURN VALUES

This function returns a pointer to the allocated memory on success, and NULL otherwise.

ERRORS

NNG_ENOMEM

Insufficient free memory to collect statistics.

NNG_ENOTSUP

Statistics are not supported (compile time option).

SEE ALSO

nng_stats_free(3), nng_stat_child(3), nng_stat_desc(3), nng_stat_name(3), nng_stat_next(3), nng_stat_string(3), nng_stat_type(3), nng_stat_timestamp(3), nng_stat_unit(3), nng_stat_value(3), nng_stat(5), nng(7)

2024-10-11