Obtaining Status Information

Once you have a valid LO-status structure, you can use the accessor functions to obtain the status information from this structure. Table 42 shows the status information that an LO-status structure contains and the corresponding LO-status accessor functions.

Table 42. Status Information in the LO-Status Structure
Status Information	LO-Status Accessor Function
Last-access time This value is available only if the last-access time attribute (MI_LO_ATTR_KEEP_LASTACCESS_TIME) is set for this smart large object.	mi_lo_stat_atime( )
Storage characteristics These characteristics are stored in an LO-specification structure. Use the LO-specification accessor functions (see Defining User-Specified Storage Characteristics) to obtain information from this structure.	mi_lo_stat_cspec( )
Last-change time	mi_lo_stat_ctime( )
Last-modification time	mi_lo_stat_mtime_sec( ), mi_lo_stat_mtime_usec( )
Reference count	mi_lo_stat_refcnt( )
Size	mi_lo_stat_size( )

Table 42. Status Information in the LO-Status Structure

Status Information

LO-Status Accessor Function

Last-access time

This value is available only if the last-access time attribute (MI_LO_ATTR_KEEP_LASTACCESS_TIME) is set for this smart large object.

mi_lo_stat_atime( )

Storage characteristics

These characteristics are stored in an LO-specification structure. Use the LO-specification accessor functions (see Defining User-Specified Storage Characteristics) to obtain information from this structure.

mi_lo_stat_cspec( )

Last-change time

mi_lo_stat_ctime( )

Last-modification time

mi_lo_stat_mtime_sec( ), mi_lo_stat_mtime_usec( )

Reference count

mi_lo_stat_refcnt( )

Size

mi_lo_stat_size( )

The LO-status structure, MI_LO_STAT, is an opaque structure to DataBlade API modules. Do not access its internal structure directly. The internal structure of MI_LO_STAT may change in future releases. Therefore, to create portable code, always use the LO-status accessor functions for this structure.

The following code fragment obtains the reference count from an LO-status structure that the LO_stat variable references:

MI_CONNECTION *conn; MI_LO_HANDLE *LO_hdl; MI_LO_FD LO_fd; MI_LO_STAT *LO_stat = NULL; /* DataBlade API allocates */ mi_integer ref_count, err; ... /* Open the selected large object */ LO_fd = mi_lo_open(conn, LO_hdl, MI_LO_RDONLY); if ( LO_fd == MI_ERROR ) /* handle error */ /* Allocate LO-specification structure and get status * information for the opened smart large object */ if ( mi_lo_stat(conn, LO_fd, &LO_stat) != MI_OK ) /* handle error */ else { /* get reference count for this smart large object */ ref_count = mi_lo_stat_refcnt(LO_stat); /* free the LO-status structure */ err = mi_lo_stat_free(LO_stat); }

The mi_lo_open( ) function opens the smart large object that the LO handle, LO_hdl, identifies. The mi_lo_stat( ) function then obtains the status information for this open smart large object. The mi_lo_stat( ) function performs the following tasks:

Once the LO-status structure contains the status information, the mi_lo_stat_refcnt( ) accessor function obtains the reference count from the LO-status structure and returns it into the ref_count variable. When the code no longer needs the LO-status structure, it frees this structure with the mi_lo_stat_free( ) function.