NetBSD/common/lib/libprop/prop_data.3

.\"	$NetBSD: prop_data.3,v 1.6 2008/04/30 13:10:46 martin Exp $
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.\" Copyright (c) 2006 The NetBSD Foundation, Inc.
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jason R. Thorpe.
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.Dd April 22, 2006
.Dt PROP_DATA 3
.Os
.Sh NAME
.Nm prop_data ,
.Nm prop_data_create_data ,
.Nm prop_data_create_data_nocopy ,
.Nm prop_data_copy ,
.Nm prop_data_size ,
.Nm prop_data_data ,
.Nm prop_data_data_nocopy ,
.Nm prop_data_equals ,
.Nm prop_data_equals_data
.Nd opaque data value property object
.Sh LIBRARY
.Lb libprop
.Sh SYNOPSIS
.In prop/proplib.h
.\"
.Ft prop_data_t
.Fn prop_data_create_data "const void *blob" "size_t len"
.Ft prop_data_t
.Fn prop_data_create_data_nocopy "const void *blob" "size_t len"
.\"
.Ft prop_data_t
.Fn prop_data_copy "prop_data_t data"
.\"
.Ft void *
.Fn prop_data_data "prop_data_t data"
.Ft size_t
.Fn prop_data_size "prop_data_t data"
.Ft const void *
.Fn prop_data_data_nocopy "prop_data_t data"
.\"
.Ft bool
.Fn prop_data_equals "prop_data_t dat1" "prop_data_t dat2"
.Ft bool
.Fn prop_data_equals_data "prop_data_t data" "const void *blob" "size_t len"
.Sh DESCRIPTION
The
.Nm prop_data
family of functions operate on an opaque data value property object type.
.Bl -tag -width "xxxxx"
.It Fn prop_data_create_data "const void *blob" "size_t len"
Create a data object that contains a copy of
.Fa blob
with size
.Fa len .
Returns
.Dv NULL
on failure.
.It Fn prop_data_create_data_nocopy "const void *blob" "size_t len"
Create a data object that contains a reference to
.Fa blob
with size
.Fa len .
Returns
.Dv NULL
on failure.
.It Fn prop_data_copy "prop_data_t data"
Copy a data object.
If the data object being copied is an external data reference,
then the copy also references the same external data.
Returns
.Dv NULL
on failure.
.It Fn prop_data_size "prop_data_t data"
Returns the size of the data object.
If the supplied object isn't a data object, zero is returned.
.It Fn prop_data_data "prop_data_t data"
Returns a copy of the data object's contents.
The caller is responsible for freeing the returned buffer.
If the supplied object isn't a data object or
if the data container is empty,
.Dv NULL
is returned.
.Pp
In user space, the buffer is allocated using
.Xr malloc 3 .
In the kernel, the buffer is allocated using
.Xr malloc 9
using the malloc type
.Dv M_TEMP .
.It Fn prop_data_data_nocopy "prop_data_t data"
Returns an immutable reference to the contents of the data object.
If the supplied object isn't a data object,
.Dv NULL
is returned.
.It Fn prop_data_equals "prop_data_t dat1" "prop_data_t dat2"
Returns
.Dv true
if the two data objects are equivalent.
If at least one of the supplied objects isn't a data object,
.Dv false
is returned.
.It Fn prop_data_equals_data "prop_data_t data" "const void *blob" "size_t len"
Returns
.Dv true
if the data object's value is equivalent to
.Fa blob
with size
.Fa len .
If the supplied object isn't a data object,
.Dv false
is returned.
.El
.Sh SEE ALSO
.Xr prop_array 3 ,
.Xr prop_bool 3 ,
.Xr prop_dictionary 3 ,
.Xr prop_number 3 ,
.Xr prop_object 3 ,
.Xr prop_string 3 ,
.Xr proplib 3
.Sh HISTORY
The
.Nm proplib
property container object library first appeared in
.Nx 4.0 .