函数 flst_get_first

/********************************************************************//**
Gets list first node address.
@return    file address */
UNIV_INLINE
fil_addr_t
flst_get_first(
/*===========*/
    const flst_base_node_t*    base,    /*!< in: pointer to base node */
    mtr_t*            mtr)    /*!< in: mini-transaction handle */
{
    return(flst_read_addr(base + FLST_FIRST, mtr));
}


#define    FLST_FIRST    4

/********************************************************************//**
Reads a file address.
@return    file address */
UNIV_INLINE
fil_addr_t
flst_read_addr(
/*===========*/
    const fil_faddr_t*    faddr,    /*!< in: pointer to file faddress */
    mtr_t*            mtr)    /*!< in: mini-transaction handle */
{
    fil_addr_t    addr;

    ut_ad(faddr && mtr);

    addr.page = mtr_read_ulint(faddr + FIL_ADDR_PAGE, MLOG_4BYTES, mtr);
    addr.boffset = mtr_read_ulint(faddr + FIL_ADDR_BYTE, MLOG_2BYTES,
                      mtr);
    ut_a(addr.page == FIL_NULL || addr.boffset >= FIL_PAGE_DATA);
    ut_a(ut_align_offset(faddr, UNIV_PAGE_SIZE) >= FIL_PAGE_DATA);
    return(addr);
}

#define FIL_ADDR_PAGE    0
#define FIL_ADDR_BYTE    4
#define FIL_PAGE_DATA   38