PROP_DATA(3)

PROP_DATA(3) | Library Functions Manual | PROP_DATA(3)

# NAME

`prop_data`, `prop_data_create_copy`, `prop_data_create_nocopy`, `prop_data_copy`, `prop_data_size`, `prop_data_value`, `prop_data_copy_value`, `prop_data_equals`, `prop_data_equals_data` —
opaque data value property object

# LIBRARY

Property Container Object Library (libprop, -lprop)

# SYNOPSIS

`#include <prop/proplib.h>`

prop_data_t
`prop_data_create_copy`(const void *blob, size_t len);

prop_data_t
`prop_data_create_nocopy`(const void *blob, size_t len);

prop_data_t
`prop_data_copy`(prop_data_t data);

const void *
`prop_data_value`(prop_data_t data);

bool
`prop_data_copy_value`(prop_data_t data, void *buf, size_t buflen);

size_t
`prop_data_size`(prop_data_t data);

bool
`prop_data_equals`(prop_data_t dat1, prop_data_t dat2);

bool
`prop_data_equals_data`(prop_data_t data, const void *blob, size_t len);

# DESCRIPTION

The `prop_data` family of functions operate on an opaque data value property object type.

`prop_data_create_copy`(const void *blob, size_t len)
  Create a data object that contains a copy of blob with size len. Returns `NULL` on failure.
`prop_data_create_nocopy`(const void *blob, size_t len)
  Similar to `prop_data_create_copy`(), but is allowed to not create aan internal copy of the opaque data, instead referencing the buffer passed by the caller. Caution must be exercised because data objects can have an indefinite lifespan. The caller must therefore ensure that the provided buffer reference will also be valid indefinitely. This is provided as a memory optimization; it is not guaranteed that the returned data object will reference the provided buffer, and thus callers should not rely on this behavior. Returns `NULL` on failure.
`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 `NULL` on failure.
`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.
`prop_data_value`(prop_data_t data)
  Returns a reference to the data object's buffer. If the supplied object isn't a data object or if the data container is empty, `NULL` is returned.
`prop_data_copy_value`(prop_data_t data, void *buf, size_t buflen)
  Copies the contents of the data object into the supplied buffer of the specified size. Returns `true` if the copy succeeds and `false` iff the supplied buffer is not large enough or if the object is not a data object.
`prop_data_equals`(prop_data_t dat1, prop_data_t dat2)
  Returns `true` if the two data objects are equivalent. If at least one of the supplied objects isn't a data object, `false` is returned.
`prop_data_equals_data`(prop_data_t data, const void *blob, size_t len)
  Returns `true` if the data object's value is equivalent to blob with size len. If the supplied object isn't a data object, `false` is returned.

# SEE ALSO

prop_array(3), prop_bool(3), prop_dictionary(3), prop_number(3), prop_object(3), prop_string(3), proplib(3)

# HISTORY

The proplib(3) property container object library first appeared in NetBSD 4.0. Support for mutable data objects was deprecated in NetBSD 10.0.

June 2, 2020 | NetBSD 10.1