PROP_INGEST(3) | Library Functions Manual | PROP_INGEST(3) |
prop_ingest
,
prop_ingest_context_alloc
,
prop_ingest_context_free
,
prop_ingest_context_error
,
prop_ingest_context_type
,
prop_ingest_context_key
,
prop_ingest_context_private
,
prop_dictionary_ingest
—
#include <prop/proplib.h>
prop_ingest_context_t
prop_ingest_context_alloc
(void
*private);
void
prop_ingest_context_free
(prop_ingest_context_t
ctx);
prop_ingest_error_t
prop_ingest_context_error
(prop_ingest_context_t
ctx);
prop_type_t
prop_ingest_context_type
(prop_ingest_context_t
ctx);
const char *
prop_ingest_context_key
(prop_ingest_context_t
ctx);
void *
prop_ingest_context_private
(prop_ingest_context_t
ctx);
bool
prop_dictionary_ingest
(prop_dictionary_t
dict, const
prop_ingest_table_entry rules[],
prop_ingest_context_t
ctx);
typedef bool
(*prop_ingest_handler_t)
(prop_ingest_context_t,
prop_object_t);
prop_dictionary_ingest
() function provides a
convenient way to convert a property list into an arbitrary binary format or
to extract values from dictionaries in a way that is convenient to an
application (for configuration files, for example).
prop_dictionary_ingest
() is driven by a
table of rules provided by the application. Each rule consists of three
items:
PROP_TYPE_UNKNOWN
to specify that any type is
allowed).prop_ingest_handler_t
that will perform the translation for the application.The table is constructed using a series of macros as follows:
static const prop_ingest_table_entry ingest_rules[] = { PROP_INGEST("file-name", PROP_TYPE_STRING, ingest_filename), PROP_INGEST("count", PROP_TYPE_NUMBER, ingest_count), PROP_INGEST_OPTIONAL("required", PROP_TYPE_BOOL, ingest_required), PROP_INGEST_OPTIONAL("extra", PROP_TYPE_UNKNOWN, ingest_extra), PROP_INGEST_END };
The PROP_INGEST
macro specifies that the
key is required to be present in the dictionary. The
PROP_INGEST_OPTIONAL
macro specifies that the
presence of the key in the dictionary is optional. The
PROP_INGEST_END
macro marks the end of the rules
table.
In each case, prop_dictionary_ingest
()
looks up the rule's key in the dictionary. If an object is present in the
dictionary at that key, its type is checked against the type specified in
the rule. A type specification of PROP_TYPE_UNKNOWN
allows the object to be of any type. If the object does not exist and the
rule is not marked as optional, then an error is returned. Otherwise, the
handler specified in the rule is invoked with the ingest context and the
object (or NULL
if the key does not exist in the
dictionary). The handler should return false
if the
value of the object is invalid to indicate failure and
true
otherwise.
The ingest context contains several pieces of information that are useful during the ingest process. The context also provides specific error information should the ingest fail.
prop_ingest_context_alloc
(void
*private)NULL
on failure.prop_ingest_context_free
(prop_ingest_context_t
ctx)prop_ingest_context_error
(prop_ingest_context_t
ctx)PROP_INGEST_ERROR_NO_ERROR
PROP_INGEST_ERROR_NO_KEY
PROP_INGEST_ERROR_WRONG_TYPE
PROP_INGEST_ERROR_HANDLER_FAILED
false
.prop_ingest_context_type
(prop_ingest_context_t
ctx)prop_ingest_context_key
(prop_ingest_context_t
ctx)prop_ingest_context_private
(prop_ingest_context_t
ctx)prop_ingest_context_alloc
().January 21, 2008 | NetBSD 9.2 |