ut0byte.ic
上传用户:tsgydb
上传日期:2007-04-14
资源大小:10674k
文件大小:7k
- /******************************************************************
- Utilities for byte operations
- (c) 1994, 1995 Innobase Oy
- Created 5/30/1994 Heikki Tuuri
- *******************************************************************/
- /***********************************************************
- Creates a 64-bit dulint out of two ulints. */
- UNIV_INLINE
- dulint
- ut_dulint_create(
- /*=============*/
- /* out: created dulint */
- ulint high, /* in: high-order 32 bits */
- ulint low) /* in: low-order 32 bits */
- {
- dulint res;
- ut_ad(high <= 0xFFFFFFFF);
- ut_ad(low <= 0xFFFFFFFF);
- res.high = high;
- res.low = low;
- return(res);
- }
- /***********************************************************
- Gets the high-order 32 bits of a dulint. */
- UNIV_INLINE
- ulint
- ut_dulint_get_high(
- /*===============*/
- /* out: 32 bits in ulint */
- dulint d) /* in: dulint */
- {
- return(d.high);
- }
- /***********************************************************
- Gets the low-order 32 bits of a dulint. */
- UNIV_INLINE
- ulint
- ut_dulint_get_low(
- /*==============*/
- /* out: 32 bits in ulint */
- dulint d) /* in: dulint */
- {
- return(d.low);
- }
- /***********************************************************
- Tests if a dulint is zero. */
- UNIV_INLINE
- ibool
- ut_dulint_is_zero(
- /*==============*/
- /* out: TRUE if zero */
- dulint a) /* in: dulint */
- {
- if ((a.low == 0) && (a.high == 0)) {
- return(TRUE);
- }
- return(FALSE);
- }
- /***********************************************************
- Compares two dulints. */
- UNIV_INLINE
- int
- ut_dulint_cmp(
- /*==========*/
- /* out: -1 if a < b, 0 if a == b,
- 1 if a > b */
- dulint a, /* in: dulint */
- dulint b) /* in: dulint */
- {
- if (a.high > b.high) {
- return(1);
- } else if (a.high < b.high) {
- return(-1);
- } else if (a.low > b.low) {
- return(1);
- } else if (a.low < b.low) {
- return(-1);
- } else {
- return(0);
- }
- }
- /***********************************************************
- Calculates the max of two dulints. */
- UNIV_INLINE
- dulint
- ut_dulint_get_max(
- /*==============*/
- /* out: max(a, b) */
- dulint a, /* in: dulint */
- dulint b) /* in: dulint */
- {
- if (ut_dulint_cmp(a, b) > 0) {
- return(a);
- }
- return(b);
- }
- /***********************************************************
- Calculates the min of two dulints. */
- UNIV_INLINE
- dulint
- ut_dulint_get_min(
- /*==============*/
- /* out: min(a, b) */
- dulint a, /* in: dulint */
- dulint b) /* in: dulint */
- {
- if (ut_dulint_cmp(a, b) > 0) {
- return(b);
- }
- return(a);
- }
- /***********************************************************
- Adds a ulint to a dulint. */
- UNIV_INLINE
- dulint
- ut_dulint_add(
- /*==========*/
- /* out: sum a + b */
- dulint a, /* in: dulint */
- ulint b) /* in: ulint */
- {
- if (0xFFFFFFFF - b >= a.low) {
- a.low += b;
- return(a);
- }
- a.low = a.low - (0xFFFFFFFF - b) - 1;
- a.high++;
- return(a);
- }
- /***********************************************************
- Subtracts a ulint from a dulint. */
- UNIV_INLINE
- dulint
- ut_dulint_subtract(
- /*===============*/
- /* out: a - b */
- dulint a, /* in: dulint */
- ulint b) /* in: ulint, b <= a */
- {
- if (a.low >= b) {
- a.low -= b;
- return(a);
- }
- b -= a.low + 1;
- a.low = 0xFFFFFFFF - b;
- ut_ad(a.high > 0);
-
- a.high--;
- return(a);
- }
- /***********************************************************
- Subtracts a dulint from another. NOTE that the difference must be positive
- and smaller that 4G. */
- UNIV_INLINE
- ulint
- ut_dulint_minus(
- /*============*/
- /* out: a - b */
- dulint a, /* in: dulint; NOTE a must be >= b and at most
- 2 to power 32 - 1 greater */
- dulint b) /* in: dulint */
- {
- ulint diff;
- if (a.high == b.high) {
- ut_ad(a.low >= b.low);
- return(a.low - b.low);
- }
- ut_ad(a.high == b.high + 1);
- diff = (ulint)(0xFFFFFFFF - b.low);
- diff += 1 + a.low;
- ut_ad(diff > a.low);
-
- return(diff);
- }
- /************************************************************
- Rounds a dulint downward to a multiple of a power of 2. */
- UNIV_INLINE
- dulint
- ut_dulint_align_down(
- /*=================*/
- /* out: rounded value */
- dulint n, /* in: number to be rounded */
- ulint align_no) /* in: align by this number which must be a
- power of 2 */
- {
- ulint low, high;
- ut_ad(align_no > 0);
- ut_ad(((align_no - 1) & align_no) == 0);
- low = ut_dulint_get_low(n);
- high = ut_dulint_get_high(n);
-
- low = low & ~(align_no - 1);
- return(ut_dulint_create(high, low));
- }
- /************************************************************
- Rounds a dulint upward to a multiple of a power of 2. */
- UNIV_INLINE
- dulint
- ut_dulint_align_up(
- /*===============*/
- /* out: rounded value */
- dulint n, /* in: number to be rounded */
- ulint align_no) /* in: align by this number which must be a
- power of 2 */
- {
- return(ut_dulint_align_down(ut_dulint_add(n, align_no - 1), align_no));
- }
- /************************************************************
- The following function calculates the value of an integer n rounded
- to the least product of align_no which is >= n. align_no
- has to be a power of 2. */
- UNIV_INLINE
- ulint
- ut_calc_align(
- /*==========*/
- /* out: rounded value */
- ulint n, /* in: number to be rounded */
- ulint align_no) /* in: align by this number */
- {
- ut_ad(align_no > 0);
- ut_ad(((align_no - 1) & align_no) == 0);
- return((n + align_no - 1) & ~(align_no - 1));
- }
- /*************************************************************
- The following function rounds up a pointer to the nearest aligned address. */
- UNIV_INLINE
- void*
- ut_align(
- /*=====*/
- /* out: aligned pointer */
- void* ptr, /* in: pointer */
- ulint align_no) /* in: align by this number */
- {
- ut_ad(align_no > 0);
- ut_ad(((align_no - 1) & align_no) == 0);
- ut_ad(ptr);
- ut_ad(sizeof(void*) == sizeof(ulint));
- return((void*)((((ulint)ptr) + align_no - 1) & ~(align_no - 1)));
- }
- /************************************************************
- The following function calculates the value of an integer n rounded
- to the biggest product of align_no which is <= n. align_no has to be a
- power of 2. */
- UNIV_INLINE
- ulint
- ut_calc_align_down(
- /*===============*/
- /* out: rounded value */
- ulint n, /* in: number to be rounded */
- ulint align_no) /* in: align by this number */
- {
- ut_ad(align_no > 0);
- ut_ad(((align_no - 1) & align_no) == 0);
- return(n & ~(align_no - 1));
- }
- /*************************************************************
- The following function rounds down a pointer to the nearest
- aligned address. */
- UNIV_INLINE
- void*
- ut_align_down(
- /*==========*/
- /* out: aligned pointer */
- void* ptr, /* in: pointer */
- ulint align_no) /* in: align by this number */
- {
- ut_ad(align_no > 0);
- ut_ad(((align_no - 1) & align_no) == 0);
- ut_ad(ptr);
- ut_ad(sizeof(void*) == sizeof(ulint));
- return((void*)((((ulint)ptr)) & ~(align_no - 1)));
- }
- /*********************************************************************
- Gets the nth bit of a ulint. */
- UNIV_INLINE
- ibool
- ut_bit_get_nth(
- /*===========*/
- /* out: TRUE if nth bit is 1; 0th bit is defined to
- be the least significant */
- ulint a, /* in: ulint */
- ulint n) /* in: nth bit requested */
- {
- ut_ad(n < 8 * sizeof(ulint));
- ut_ad(TRUE == 1);
- return(1 & (a >> n));
- }
- /*********************************************************************
- Sets the nth bit of a ulint. */
- UNIV_INLINE
- ulint
- ut_bit_set_nth(
- /*===========*/
- /* out: the ulint with the bit set as requested */
- ulint a, /* in: ulint */
- ulint n, /* in: nth bit requested */
- ibool val) /* in: value for the bit to set */
- {
- ut_ad(n < 8 * sizeof(ulint));
- ut_ad(TRUE == 1);
- if (val) {
- return((1 << n) | a);
- } else {
- return(~(1 << n) & a);
- }
- }