Module box

type box_function_ctx_t¶: Opaque structure passed to a C stored procedure

int box_return_tuple(box_function_ctx_t *ctx, box_tuple_t *tuple)¶

Return a tuple from a C stored procedure.

The returned tuple is automatically reference-counted by Tarantool. An example program that uses box_return_tuple() is write.c.

Parameters:	ctx (box_function_ctx_t) – an opaque structure passed to the C stored procedure by Tarantool tuple* (box_tuple_t*) – a tuple to return
Returns:	-1 on error (perhaps, out of memory; check box_error_last())
Returns:	0 otherwise

int box_return_mp(box_function_ctx_t *ctx, const char *mp, const char *mp_end)¶

Return a pointer to a series of bytes in MessagePack format.

This can be used instead of box_return_tuple() – it can send the same value, but as MessagePack instead of as a tuple object. It may be simpler than box_return_tuple() when the result is small, for example a number or a boolean or a short string. It will also be faster than box_return_tuple(), if the result is that users save time by not creating a tuple every time they want to return something from a C function.

On the other hand, if an already-existing tuple was obtained from an iterator, then it would be faster to return the tuple via box_return_tuple() rather than extracting its parts and sending them via box_return_mp().

Parameters:	ctx (box_function_ctx_t) – an opaque structure passed to the C stored procedure by Tarantool mp (char) – the first MessagePack byte mp_end (char*) – after the last MessagePack byte
Returns:	-1 on error (perhaps, out of memory; check box_error_last())
Returns:	0 otherwise

For example, if mp is a buffer, and mp_end is a return value produced by encoding a single MP_UINT scalar value with mp_end=mp_encode_uint(mp,1);, then box_return_mp(ctx,mp,mp_end); should return 0.

uint32_t box_space_id_by_name(const char *name, uint32_t len)¶

Find space id by name.

This function performs a SELECT request on the _vspace system space.

Parameters:	name (const char) – space name len* (uint32_t) – length of `name`
Returns:	`BOX_ID_NIL` on error or if not found (check box_error_last())
Returns:	space_id otherwise

Parameters:	space_id (uint32_t) – space identifier name (const char) – index name len* (uint32_t) – length of `name`
Returns:	`BOX_ID_NIL` on error or if not found (check box_error_last())
Returns:	space_id otherwise

Parameters:	data (const char) – begin of MessagePack to push data_end* (const char*) – end of MessagePack to push
Returns:	-1 on error (check box_error_last())
Returns:	0 otherwise

Parameters:	seq_id (uint32_t) – sequence identifier result (int64_t) – pointer to a variable where the current sequence value will be stored on success.
Returns:	0 on success and -1 otherwise. In case of an error user could get it via `box_error_last()`.

Parameters:	space_id (uint32_t) – space identifier index_id (uint32_t) – index identifier key (const char) – encoded key in MsgPack Array format ([ field1, field2, …]) key_end* (const char) – end of a `key` ops* (const char) – encoded operations in MsgPack Array format, e.g. `[[ '=', field_id, value ], ['!', 2, 'xxx']]` ops_end* (const char) – end of an `ops` section index_base* (int) – 0 if field_ids are zero-based as in C, 1 if field ids are 1-based as in Lua result (box_tuple_t**) – output argument. An old tuple. Can be set to NULL to discard result
Returns:	-1 on error (check box_error_last())
Returns:	0 otherwise

Parameters:	space_id (uint32_t) – space identifier index_id (uint32_t) – index identifier tuple (const char) – encoded tuple in MsgPack Array format ([ field1, field2, …]) tuple_end* (const char) – end of a `tuple` ops* (const char) – encoded operations in MsgPack Array format, e.g. `[[ '=', field_id, value ], ['!', 2, 'xxx']]` ops_end* (const char) – end of a `ops` index_base* (int) – 0 if field_ids are zero-based as in C, 1 if field ids are 1-based as in Lua result (box_tuple_t**) – output argument. An old tuple. Can be set to NULL to discard result
Returns:	-1 on error (check box_error_last())
Returns:	0 otherwise

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Module box