Module index¶

box_iterator_t¶: A space iterator

enum iterator_type¶

Controls how to iterate over tuples in an index. Different index types support different iterator types. For example, one can start iteration from a particular value (request key) and then retrieve all tuples where keys are greater or equal (= GE) to this key.

If iterator type is not supported by the selected index type, iterator constructor must fail with ER_UNSUPPORTED. To be selectable for primary key, an index must support at least ITER_EQ and ITER_GE types.

NULL value of request key corresponds to the first or last key in the index, depending on iteration direction. (first key for GE and GT types, and last key for LE and LT). Therefore, to iterate over all tuples in an index, one can use ITER_GE or ITER_LE iteration types with start key equal to NULL. For ITER_EQ, the key must not be NULL.

enumerator ITER_EQ¶: key == x ASC order

enumerator ITER_REQ¶: key == x DESC order

enumerator ITER_ALL¶: all tuples

enumerator ITER_LT¶: key < x

enumerator ITER_LE¶: key <= x

enumerator ITER_GE¶: key >= x

enumerator ITER_GT¶: key > x

enumerator ITER_BITS_ALL_SET¶: all bits from x are set in key

enumerator ITER_BITS_ANY_SET¶: at least one x’s bit is set

enumerator ITER_BITS_ALL_NOT_SET¶: all bits are not set

enumerator ITER_OVERLAPS¶: key overlaps x

enumerator ITER_NEIGHBOR¶: tuples in distance ascending order from specified point

box_iterator_t *box_index_iterator(uint32_t space_id, uint32_t index_id, int type, const char *key, const char *key_end)¶

Allocate and initialize iterator for space_id, index_id.

The returned iterator must be destroyed by box_iterator_free.

Parameters:	space_id (uint32_t) – space identifier index_id (uint32_t) – index identifier type (int) – iterator_type *char key** (const) – encode key in MsgPack Array format ([part1, part2, …]) *char key_end** (const) – the end of encoded `key`
Returns:	NULL on error (check :ref:box_error_last`c_api-error-box_error_last>`)
Returns:	iterator otherwise

int box_iterator_next(box_iterator_t *iterator, box_tuple_t **result)¶

Retrieve the next item from the iterator.

Parameters:	iterator (box_iterator_t) – an iterator returned by :ref:box_index_iterator`c_api-box_index-box_index_iterator>` result* (box_tuple_t**) – output argument. result a tuple or NULL if there is no more data.
Returns:	-1 on error (check :ref:box_error_last`c_api-error-box_error_last>`)
Returns:	0 on success. The end of data is not an error.

void box_iterator_free(box_iterator_t *iterator)¶

Destroy and deallocate iterator.

Parameters:	iterator (box_iterator_t*) – an iterator returned by :ref:box_index_iterator`c_api-box_index-box_index_iterator>`

ssize_t box_index_len(uint32_t space_id, uint32_t index_id)¶

Return the number of element in the index.

Parameters:	space_id (uint32_t) – space identifier index_id (uint32_t) – index identifier
Returns:	-1 on error (check :ref:box_error_last`c_api-error-box_error_last>`)
Returns:	>= 0 otherwise

ssize_t box_index_bsize(uint32_t space_id, uint32_t index_id)¶

Return the number of bytes used in memory by the index.

Parameters:	space_id (uint32_t) – space identifier index_id (uint32_t) – index identifier
Returns:	-1 on error (check :ref:box_error_last`c_api-error-box_error_last>`)
Returns:	>= 0 otherwise

int box_index_random(uint32_t space_id, uint32_t index_id, uint32_t rnd, box_tuple_t **result)¶

Return a random tuple from the index (useful for statistical analysis).

Parameters:	space_id (uint32_t) – space identifier index_id (uint32_t) – index identifier rnd (uint32_t) – random seed result (box_tuple_t**) – output argument. result a tuple or NULL if there is no tuples in space

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Module index¶