rseg_id - get rollback tablespace id 2. get data from undo log 4UFQTPG3PMM1PJOUFS /** Decodes a roll pointer. */ inline void trx_undo_decode_roll_ptr ( roll_ptr_t roll_ptr, /*!< in: roll pointer */ ibool *is_insert, /*!< out: TRUE if insert undo log */ ulint *rseg_id, /*!< out: rollback segment id */ page_no_t *page_no, /*!< out: page number */ ulint *offset) /*!< out: offset of the und o entry within page */ { ut_ad(roll_ptr < (1ULL << 56)) ; *offset = (ulint)roll_ptr & 0xFFFF ; roll_ptr >>= 16 ; *page_no = (ulint)roll_ptr & 0xFFFFFFFF ; roll_ptr >>= 32 ; *rseg_id = (ulint)roll_ptr & 0x7F ; roll_ptr >>= 7 ; *is_insert = (ibool)roll_ptr; /* TRUE==1 */ }