Рейтинг@Mail.ru

Модуль tuple

Замечание

Документация находится в процессе перевода и может отставать от английской версии.

Модуль tuple

box_tuple_format_t
box_tuple_format_t *box_tuple_format_default(void)

Tuple format.

Each Tuple has an associated format (class). Default format is used to create tuples which are not attached to any particular space.

box_tuple_t

Tuple

box_tuple_t *box_tuple_new(box_tuple_format_t *format, const char *tuple, const char *tuple_end)

Allocate and initialize a new tuple from raw MsgPack Array data.

Параметры:
  • format (box_tuple_format_t*) – tuple format. Use box_tuple_format_default() to create space-independent tuple.
  • char* tuple (const) – tuple data in MsgPack Array format ([field1, field2, …])
  • char* tuple_end (const) – the end of data
Результат:

NULL on out of memory

Результат:

tuple otherwise

See also: box.tuple.new()

Предупреждение

When working with tuples, it is the developer’s responsibility to ensure that enough space is allocated, taking especial caution when writing to them with msgpuck functions such as mp_encode_array().

int box_tuple_ref(box_tuple_t *tuple)

Increase the reference counter of tuple.

Tuples are reference counted. All functions that return tuples guarantee that the last returned tuple is reference counted internally until the next call to API function that yields or returns another tuple.

You should increase the reference counter before taking tuples for long processing in your code. Such tuples will not be garbage collected even if another fiber removes them from a space. After processing, decrement the reference counter using box_tuple_unref(), otherwise the tuple will leak.

Параметры:
Результат:

-1 on error

Результат:

0 otherwise

See also: box_tuple_unref()

void box_tuple_unref(box_tuple_t *tuple)

Decrease the reference counter of tuple.

Параметры:
Результат:

-1 on error

Результат:

0 otherwise

See also: box_tuple_ref()

uint32_t box_tuple_field_count(const box_tuple_t *tuple)

Return the number of fields in a tuple (the size of MsgPack Array).

Параметры:
size_t box_tuple_bsize(const box_tuple_t *tuple)

Return the number of bytes used to store internal tuple data (MsgPack Array).

Параметры:
ssize_t box_tuple_to_buf(const box_tuple_t *tuple, char *buf, size_t size)

Dump raw MsgPack data to the memory buffer buf of size size.

Store tuple fields in the memory buffer.

Upon successful return, the function returns the number of bytes written. If buffer size is not enough then the return value is the number of bytes which would have been written if enough space had been available.

Результат:-1 on error
Результат:number of bytes written on success.
box_tuple_format_t *box_tuple_format(const box_tuple_t *tuple)

Return the associated format.

Параметры:
Результат:

tuple format

const char *box_tuple_field(const box_tuple_t *tuple, uint32_t field_id)

Return the raw tuple field in MsgPack format. The result is a pointer to raw MessagePack data which can be decoded with mp_decode functions, for an example see the tutorial program read.c.

The buffer is valid until the next call to a box_tuple_* function.

Параметры:
  • tuple (box_tuple_t*) – a tuple
  • field_id (uint32_t) – zero-based index in MsgPack array.
Результат:

NULL if i >= box_tuple_field_count()

Результат:

msgpack otherwise

enum field_type
enumerator FIELD_TYPE_ANY
enumerator FIELD_TYPE_UNSIGNED
enumerator FIELD_TYPE_STRING
enumerator FIELD_TYPE_ARRAY
enumerator FIELD_TYPE_NUMBER
enumerator FIELD_TYPE_INTEGER
enumerator FIELD_TYPE_SCALAR
enumerator field_type_MAX

Possible data types for tuple fields.

One cannot use STRS/ENUM macros for types because there is a mismatch between enum name (STRING) and type name literal («STR»). STR is already used as a type in Objective C.

typedef struct key_def box_key_def_t

Key definition

box_key_def_t *box_key_def_new(uint32_t *fields, uint32_t *types, uint32_t part_count)

Create a key definition with the key fields with passed types on passed positions.

May be used for tuple format creation and/or tuple comparison.

Параметры:
  • fields (uint32_t*) – array with key field identifiers
  • types (uint32_t) – array with key field types
  • part_count (uint32_t) – the number of key fields
Результат:

key definition on success

Результат:

NULL on error

void box_key_def_delete(box_key_def_t *key_def)

Delete a key definition

Параметры:
box_tuple_format_t *box_tuple_format_new(struct key_def *keys, uint16_t key_count)

Return new in-memory tuple format based on passed key definitions

Параметры:
  • keys (key_def) – array of keys defined for the format
  • key_count (uint16_t) – count of keys
Результат:

new tuple format on success

Результат:

NULL on error

void box_tuple_format_ref(box_tuple_format_t *format)

Increment tuple format reference count

Параметры:
void box_tuple_format_unref(box_tuple_format_t *format)

Decrement tuple format reference count

Параметры:
int box_tuple_compare(const box_tuple_t *tuple_a, const box_tuple_t *tuple_b, const box_key_def_t *key_def)

Compare tuples using key definition

Параметры:
  • box_tuple_t* tuple_a (const) – the first tuple
  • box_tuple_t* tuple_b (const) – the second tuple
  • box_key_def_t* key_def (const) – key definition
Результат:

0 if key_fields(tuple_a) == key_fields(tuple_b)

Результат:

<0 if key_fields(tuple_a) < key_fields(tuple_b)

Результат:

>0 if key_fields(tuple_a) > key_fields(tuple_b)

See also: enum field_type

int box_tuple_compare_with_key(const box_tuple_t *tuple, const char *key, const box_key_def_t *key_def);

Compare a tuple with a key using key definition

Параметры:
  • box_tuple_t* tuple (const) – tuple
  • char* key (const) – key with MessagePack array header
  • box_key_def_t* key_def (const) – key definition
Результат:

0 if key_fields(tuple) == parts(key)

Результат:

<0 if key_fields(tuple) < parts(key)

Результат:

>0 if key_fields(tuple) > parts(key)

See also: enum field_type

box_tuple_iterator_t

Tuple iterator

box_tuple_iterator_t *box_tuple_iterator(box_tuple_t *tuple)

Allocate and initialize a new tuple iterator. The tuple iterator allows iterating over fields at the root level of a MsgPack array.

Example:

box_tuple_iterator_t* it = box_tuple_iterator(tuple);
if (it == NULL) {
    // error handling using box_error_last()
}
const char* field;
while (field = box_tuple_next(it)) {
    // process raw MsgPack data
}

// rewind the iterator to the first position
box_tuple_rewind(it)
assert(box_tuple_position(it) == 0);

// rewind three fields
field = box_tuple_seek(it, 3);
assert(box_tuple_position(it) == 4);

box_iterator_free(it);
void box_tuple_iterator_free(box_tuple_iterator_t *it)

Destroy and free tuple iterator

uint32_t box_tuple_position(box_tuple_iterator_t *it)

Return zero-based next position in iterator. That is, this function returnы the field id of the field that will be returned by the next call to box_tuple_next(). Returned value is zero after initialization or rewind and box_tuple_field_count() after the end of iteration.

Параметры:
Результат:

position

void box_tuple_rewind(box_tuple_iterator_t *it)

Rewind iterator to the initial position.

Параметры:

After: box_tuple_position(it) == 0

const char *box_tuple_seek(box_tuple_iterator_t *it, uint32_t field_no)

Seek the tuple iterator.

The result is a pointer to raw MessagePack data which can be decoded with mp_decode functions, for an example see the tutorial program read.c. The returned buffer is valid until the next call to box_tuple_* API. The requested field_no is returned by the next call to box_tuple_next(it).

Параметры:
  • it (box_tuple_iterator_t*) – a tuple iterator
  • field_no (uint32_t) – field number - zero-based position in MsgPack array

After:

  • box_tuple_position(it) == field_not if returned value is not NULL.
  • box_tuple_position(it) == box_tuple_field_count(tuple) if returned value is NULL.
const char *box_tuple_next(box_tuple_iterator_t *it)

Return the next tuple field from tuple iterator.

The result is a pointer to raw MessagePack data which can be decoded with mp_decode functions, for an example see the tutorial program read.c. The returned buffer is valid until next call to box_tuple_* API.

Параметры:
Результат:

NULL if there are no more fields

Результат:

MsgPack otherwise

Before: box_tuple_position() is zero-based ID of returned field.

After: box_tuple_position(it) == box_tuple_field_count(tuple) if returned value is NULL.

box_tuple_t *box_tuple_update(const box_tuple_t *tuple, const char *expr, const char *expr_end)
box_tuple_t *box_tuple_upsert(const box_tuple_t *tuple, const char *expr, const char *expr_end)