.\" $OpenBSD: kstat_kv_init.9,v 1.2 2020/08/10 11:33:58 schwarze Exp $
.\"
.\" Copyright (c) 2020 David Gwynne <dlg@openbsd.org>
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.Dd $Mdocdate: August 10 2020 $
.Dt KSTAT_KV_INIT 9
.Os
.Sh NAME
.Nm kstat_kv_init ,
.Nm kstat_kv_unit_init ,
.Nm KSTAT_KV_INITIALIZER ,
.Nm KSTAT_KV_UNIT_INITIALIZER
.Nd kernel statistic key/value data API
.Sh SYNOPSIS
.In sys/kstat.h
.Ft void
.Fo kstat_kv_init
.Fa "struct kstat_kv *kv"
.Fa "const char *key"
.Fa "enum kstat_kv_type type"
.Fc
.Ft void
.Fo kstat_kv_unit_init
.Fa "struct kstat_kv *kv"
.Fa "const char *key"
.Fa "enum kstat_kv_type type"
.Fa "enum kstat_kv_unit unit"
.Fc
.Fo KSTAT_KV_INITIALIZER
.Fa "const char *name"
.Fa "enum kstat_kv_type type"
.Fc
.Fo KSTAT_KV_UNIT_INITIALIZER
.Fa "const char *name"
.Fa "enum kstat_kv_type type"
.Fa "enum kstat_kv_unit unit"
.Fc
.Sh DESCRIPTION
The kstat key/value data API supports the creation and maintenance of
.Vt kstat_kv
structures that can be exported to userland using the kstat API.
.Pp
A kstat key/value data payload for a
.Vt kstat
structure
.Po
created using
.Xr kstat_create 9
with
.Dv KSTAT_T_KV
as the
.Fa type
argument
.Pc
is a series of
.Vt kstat_kv
structures in memory.
kstat_kv values are typed, and the memory used to store values of
different types is either inline as part of the structure, or is
extra bytes following a structure of a specified length.
.\" .Pp
.\" kstat_kv structures contain the following fields:
.Pp
.Fn kstat_kv_init
initialises
.Fa kv
with a name specified as
.Fa key .
The type of the value is specified as
.Fa type .
.Pp
.Fn kstat_kv_unit_init
initialises
.Fa kv
with a name specified as
.Fa key .
The integer or counter type of the value is specified as
.Fa type ,
and specifies the units for the values in
.Fa unit .
.Pp
A
.Vt kstat_kv
structure can be initialised at compile time with the
.Fn KSTAT_KV_INITIALIZER
macro.
The
.Vt kstat_kv
structure will be declared with the name
.Fa key
with the type of the values as
.Fa type .
.Pp
A
.Vt kstat_kv
structure can be initialised at compile time with the
.Fn KSTAT_KV_UNIT_INITIALIZER
macro.
The
.Vt kstat_kv
structure will be declared with the name
.Fa key
with the integer or counter type of the values as
.Fa type ,
and specifies the units for the values in
.Fa unit .
.Sh SEE ALSO
.Xr kstat_create 9
.Sh HISTORY
These functions first appeared in
.Ox 6.8 .
.Sh AUTHORS
.An David Gwynne Aq Mt dlg@openbsd.org