Informix DataBlade API Programmer's Manual DataBlade API Function Descriptions

The mi_lo_spec_init() function allocates and initializes the default system storage characteristics that are used to create a new smart large object.

mi_integer mi_lo_spec_init(conn, LOspec_dptr)

MI_CONNECTION *conn;

MI_LO_SPEC **LOspec_dptr;

conn	is a pointer to the connection descriptor that a previous call to mi_open(), mi_server_connect(), or mi_server_reconnect() has established.
LOspec_dptr	is a doubly indirected pointer to an LO-specification structure for a smart large object.

Valid in Client LIBMI Application?	Valid in User-Defined Routine?
Yes	Yes

The mi_lo_spec_init() function is a constructor for the LO-specification structure. It performs the following steps to initialize an LO-specification structure:

1. It handles memory allocation for an LO-specification structure.

When the *LOspec_dptr value (a single indirect pointer to an LO-specification structure) is NULL, this function allocates an LO-
specification structure. Before you use an LO-specification structure, set *LOspec_dptr to NULL so that mi_lo_spec_init() allocates space for the LO-specification structure. When *LOspec_dptr does not point to NULL, the mi_lo_spec_init() function assumes that *LOspec_dptr points to an LO-specification structure that has already been allocated via a previous call to mi_lo_spec_init().

2. It initializes the fields in the LO-specification structure, which LOspec_dptr references.

When the smart-large-object optimizer receives this initialized LO-specification structure, it uses system-specified storage characteristics for the new smart large object.

The mi_lo_spec_init() function allocates a new LO-specification structure in the current memory duration.

Important: Before you use an LO-specification structure in a DataBlade API module, you must either allocate a new one with the mi_lo_spec_init() function or obtain one from an existing smart large object with the mi_lo_stat_cspec() function. You can use the mi_lo_colinfo_by_ids() or mi_lo_colinfo_by_name() function to obtain storage characteristics that are associated with a particular column.

Do not use system memory-allocation calls (such as malloc() or mi_alloc()) to perform memory management for LO-specification structures. Use the mi_lo_spec_init() function to create a new LO-specification structure and the mi_lo_spec_free() function to free an LO-specification structure.

See the descriptions of the following functions: mi_lo_open(), mi_lo_spec_free(), mi_lo_specget_estbytes(), mi_lo_specget_extsz(), mi_lo_specget_flags(), mi_lo_specget_maxbytes(), mi_lo_specget_sbspace(), mi_lo_specset_estbytes(), mi_lo_specset_extsz(), mi_lo_specset_flags(), mi_lo_specset_maxbytes(), mi_lo_specset_sbspace(), and mi_lo_stat_cspec().

For more information, see The LO-Specification Structure, Initializing an LO-Specification Structure, and Choosing Storage Characteristics.