jdb-iterator.c File Reference

#include <julea-config.h>
#include <glib.h>
#include <string.h>
#include <bson.h>
#include <julea.h>
#include <db/jdb-internal.h>
#include <julea-db.h>

Functions
JDBIterator *	j_db_iterator_new (JDBSchema *schema, JDBSelector *selector, GError **error)
JDBIterator *	j_db_iterator_ref (JDBIterator *iterator)
void	j_db_iterator_unref (JDBIterator *iterator)
gboolean	j_db_iterator_next (JDBIterator *iterator, GError **error)
gboolean	j_db_iterator_get_field (JDBIterator *iterator, JDBSchema *schema, gchar const *name, JDBType *type, gpointer *value, guint64 *length, GError **error)

Function Documentation

j_db_iterator_get_field()

gboolean j_db_iterator_get_field	(	JDBIterator *	iterator,
		JDBSchema *	schema,
		gchar const *	name,
		JDBType *	type,
		gpointer *	value,
		guint64 *	length,
		GError **	error
	)

Get a single value from the current entry of the iterator.

Parameters

[in]	iterator	The iterator to query.
[in]	schema	The schema the field belongs to. If the field is in the primary schema (especially if no joins are used) NULL may be passed.
[in]	name	The name of the value to retrieve.
[out]	type	The type of the retrieved value.
[out]	value	The retieved value.
[out]	length	The length of the retrieved value.
[out]	error	A GError pointer. Will point to a GError object in case of failure.

Precondition

iterator != NULL

name != NULL

type != NULL

value != NULL

*value should not be initialized

length != NULL

Postcondition

*value points to a new allocated memory region. The caller must free this later using g_free.

*length contains the length of the allocated memory region

Returns

TRUE on success, FALSE otherwise

j_db_iterator_new()

JDBIterator * j_db_iterator_new	(	JDBSchema *	schema,
		JDBSelector *	selector,
		GError **	error
	)

Allocates a new iterator.

Parameters

[in]	schema	The primary schema of the iterator.
[in]	selector	The selector to use.
[out]	error	A GError pointer. Will point to a GError object in case of failure.

Precondition

schema != NULL

selector != NULL

Returns

the new iterator or NULL on failure

j_db_iterator_next()

gboolean j_db_iterator_next	(	JDBIterator *	iterator,
		GError **	error
	)

The iterator moves to the next element.

Parameters

[in,out]	iterator	to update
[out]	error	A GError pointer. Will point to a GError object in case of failure.

Precondition

iterator != NULL

Returns

TRUE on success, FALSE otherwise

j_db_iterator_ref()

JDBIterator * j_db_iterator_ref

(

JDBIterator *

iterator

)

Increase the ref_count of the given iterator.

Parameters

[in]

iterator

the iterator to increase the ref_count

Precondition

iterator != NULL

Returns

the iterator or NULL on failure

j_db_iterator_unref()

void j_db_iterator_unref

(

JDBIterator *

iterator

)

Decrease the ref_count of the given iterator - and automatically call free if ref_count is 0. This is a noop if iterator == NULL.

Parameters

[in]

iterator

the iterator to decrease the ref_count