page0page.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

				sum_owned + page_dir_slot_get_n_owned(slot));

	/* 3. Destroy start and other slots by copying slots */
	for (i = start + n; i < n_slots; i++) {
		slot = page_dir_get_nth_slot(page, i);
		rec = page_dir_slot_get_rec(slot);

		slot = page_dir_get_nth_slot(page, i - n);
		page_dir_slot_set_rec(slot, rec);
	}

	/* 4. Update the page header */
	page_header_set_field(page, PAGE_N_DIR_SLOTS, n_slots - n);
}

/******************************************************************
Used to add n slots to the directory. Does not set the record pointers
in the added slots or update n_owned values: this is the responsibility
of the caller. */
UNIV_INLINE
void
page_dir_add_slots(
/*===============*/
	page_t*	page,	/* in: the index page */
	ulint	start,	/* in: the slot above which the new slots are added */
	ulint	n)	/* in: number of slots to add (currently only n == 1 
			allowed) */
{
	page_dir_slot_t*	slot;
	ulint			n_slots;
	ulint			i;
	rec_t*			rec;

	ut_ad(n == 1);
	
	n_slots = page_dir_get_n_slots(page);

	ut_ad(start < n_slots - 1);

	/* Update the page header */
	page_dir_set_n_slots(page, n_slots + n);

	/* Move slots up */

	for (i = n_slots - 1; i > start; i--) {

		slot = page_dir_get_nth_slot(page, i);
		rec = page_dir_slot_get_rec(slot);

		slot = page_dir_get_nth_slot(page, i + n);
		page_dir_slot_set_rec(slot, rec);
	}
}

/********************************************************************
Splits a directory slot which owns too many records. */

void
page_dir_split_slot(
/*================*/
	page_t*	page,		/* in: the index page in question */
	ulint	slot_no)	/* in: the directory slot */
{		
	rec_t*			rec;
	page_dir_slot_t*	new_slot;
	page_dir_slot_t*	prev_slot;
	page_dir_slot_t*	slot;
	ulint			i;
	ulint			n_owned;

	ut_ad(page);
	ut_ad(slot_no > 0);

	slot = page_dir_get_nth_slot(page, slot_no);
	
	n_owned = page_dir_slot_get_n_owned(slot);
	ut_ad(n_owned == PAGE_DIR_SLOT_MAX_N_OWNED + 1);

	/* 1. We loop to find a record approximately in the middle of the 
	records owned by the slot. */
	
	prev_slot = page_dir_get_nth_slot(page, slot_no - 1);
	rec = page_dir_slot_get_rec(prev_slot);

	for (i = 0; i < n_owned / 2; i++) {
		rec = page_rec_get_next(rec);
	}

	ut_ad(n_owned / 2 >= PAGE_DIR_SLOT_MIN_N_OWNED);

	/* 2. We add one directory slot immediately below the slot to be
	split. */

	page_dir_add_slots(page, slot_no - 1, 1);

	/* The added slot is now number slot_no, and the old slot is
	now number slot_no + 1 */

	new_slot = page_dir_get_nth_slot(page, slot_no);
	slot = page_dir_get_nth_slot(page, slot_no + 1);

	/* 3. We store the appropriate values to the new slot. */
	
	page_dir_slot_set_rec(new_slot, rec);
	page_dir_slot_set_n_owned(new_slot, n_owned / 2);
	
	/* 4. Finally, we update the number of records field of the 
	original slot */

	page_dir_slot_set_n_owned(slot, n_owned - (n_owned / 2));
}

/*****************************************************************
Tries to balance the given directory slot with too few records with the upper
neighbor, so that there are at least the minimum number of records owned by
the slot; this may result in the merging of two slots. */

void
page_dir_balance_slot(
/*==================*/
	page_t*	page,		/* in: index page */
	ulint	slot_no) 	/* in: the directory slot */
{
	page_dir_slot_t*	slot;
	page_dir_slot_t*	up_slot;
	ulint			n_owned;
	ulint			up_n_owned;
	rec_t*			old_rec;
	rec_t*			new_rec;

	ut_ad(page);
	ut_ad(slot_no > 0);

	slot = page_dir_get_nth_slot(page, slot_no);
	
	/* The last directory slot cannot be balanced with the upper
	neighbor, as there is none. */

	if (slot_no == page_dir_get_n_slots(page) - 1) {

		return;
	}
	
	up_slot = page_dir_get_nth_slot(page, slot_no + 1);
		
	n_owned = page_dir_slot_get_n_owned(slot);
	up_n_owned = page_dir_slot_get_n_owned(up_slot);
	
	ut_ad(n_owned == PAGE_DIR_SLOT_MIN_N_OWNED - 1);

	/* If the upper slot has the minimum value of n_owned, we will merge
	the two slots, therefore we assert: */ 
	ut_ad(2 * PAGE_DIR_SLOT_MIN_N_OWNED - 1 <= PAGE_DIR_SLOT_MAX_N_OWNED);
	
	if (up_n_owned > PAGE_DIR_SLOT_MIN_N_OWNED) {

		/* In this case we can just transfer one record owned
		by the upper slot to the property of the lower slot */
		old_rec = page_dir_slot_get_rec(slot);
		new_rec = page_rec_get_next(old_rec);
		
		rec_set_n_owned(old_rec, page_is_comp(page), 0);
		rec_set_n_owned(new_rec, page_is_comp(page), n_owned + 1);
		
		page_dir_slot_set_rec(slot, new_rec);
		
		page_dir_slot_set_n_owned(up_slot, up_n_owned -1);
	} else {
		/* In this case we may merge the two slots */
		page_dir_delete_slots(page, slot_no, 1);
	}		
}

/****************************************************************
Returns the middle record of the record list. If there are an even number
of records in the list, returns the first record of the upper half-list. */

rec_t*
page_get_middle_rec(
/*================*/
			/* out: middle record */
	page_t*	page)	/* in: page */
{
	page_dir_slot_t*	slot;
	ulint			middle;
	ulint			i;
	ulint			n_owned;
	ulint			count;
	rec_t*			rec;

	/* This many records we must leave behind */
	middle = (page_get_n_recs(page) + 2) / 2;

	count = 0;

	for (i = 0;; i++) {

		slot = page_dir_get_nth_slot(page, i);
		n_owned = page_dir_slot_get_n_owned(slot);

		if (count + n_owned > middle) {
			break;
		} else {
			count += n_owned;
		}
	}

	ut_ad(i > 0);
	slot = page_dir_get_nth_slot(page, i - 1);
	rec = page_dir_slot_get_rec(slot);
	rec = page_rec_get_next(rec);

	/* There are now count records behind rec */

	for (i = 0; i < middle - count; i++) {
		rec = page_rec_get_next(rec);
	}

	return(rec);
}
	
/*******************************************************************
Returns the number of records before the given record in chain.
The number includes infimum and supremum records. */

ulint
page_rec_get_n_recs_before(
/*=======================*/
			/* out: number of records */
	rec_t*	rec)	/* in: the physical record */
{
	page_dir_slot_t*	slot;
	rec_t*			slot_rec;
	page_t*			page;
	ulint			i;
	ulint			comp;
	lint			n	= 0;

	ut_ad(page_rec_check(rec));

	page = buf_frame_align(rec);
	comp = page_is_comp(page);

	while (rec_get_n_owned(rec, comp) == 0) {

		rec = page_rec_get_next(rec);
		n--;
	}
	
	for (i = 0; ; i++) {
		slot = page_dir_get_nth_slot(page, i);
		slot_rec = page_dir_slot_get_rec(slot);

		n += rec_get_n_owned(slot_rec, comp);

		if (rec == slot_rec) {

			break;
		}
	}

	n--;

	ut_ad(n >= 0);

	return((ulint) n);
}

/****************************************************************
Prints record contents including the data relevant only in
the index page context. */
 
void
page_rec_print(
/*===========*/
	rec_t*		rec,	/* in: physical record */
	const ulint*	offsets)/* in: record descriptor */
{
	ulint	comp	= page_is_comp(buf_frame_align(rec));

	ut_a(!comp == !rec_offs_comp(offsets));
	rec_print_new(stderr, rec, offsets);
	fprintf(stderr,
     		"            n_owned: %lu; heap_no: %lu; next rec: %lu\n",
		(ulong) rec_get_n_owned(rec, comp),
		(ulong) rec_get_heap_no(rec, comp),
		(ulong) rec_get_next_offs(rec, comp));

	page_rec_check(rec);
	rec_validate(rec, offsets);
}

/*******************************************************************
This is used to print the contents of the directory for
debugging purposes. */

void
page_dir_print(
/*===========*/
	page_t*	page,	/* in: index page */
	ulint	pr_n)	/* in: print n first and n last entries */
{
	ulint			n;
	ulint			i;
	page_dir_slot_t*	slot;

	n = page_dir_get_n_slots(page);
	
	fprintf(stderr, "--------------------------------\n"
		"PAGE DIRECTORY\n"
		"Page address %p\n"
		"Directory stack top at offs: %lu; number of slots: %lu\n",
		page, (ulong)(page_dir_get_nth_slot(page, n - 1) - page), (ulong) n);
	for (i = 0; i < n; i++) {
		slot = page_dir_get_nth_slot(page, i);
		if ((i == pr_n) && (i < n - pr_n)) {
			fputs("    ...   \n", stderr);
		}
	    	if ((i < pr_n) || (i >= n - pr_n)) {
			fprintf(stderr,
	   	   "Contents of slot: %lu: n_owned: %lu, rec offs: %lu\n",
			(ulong) i, (ulong) page_dir_slot_get_n_owned(slot),
			(ulong)(page_dir_slot_get_rec(slot) - page));
	    	}
	}
	fprintf(stderr, "Total of %lu records\n"
		"--------------------------------\n",
		(ulong) (2 + page_get_n_recs(page)));
}	
	
/*******************************************************************
This is used to print the contents of the page record list for
debugging purposes. */

void
page_print_list(
/*============*/
	page_t*		page,	/* in: index page */
	dict_index_t*	index,	/* in: dictionary index of the page */
	ulint		pr_n)	/* in: print n first and n last entries */
{
	page_cur_t	cur;
	ulint		count;
	ulint		n_recs;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	ut_a((ibool)!!page_is_comp(page) == index->table->comp);

	fprintf(stderr,
		"--------------------------------\n"
		"PAGE RECORD LIST\n"
		"Page address %p\n", page);

	n_recs = page_get_n_recs(page);

	page_cur_set_before_first(page, &cur);
	count = 0;
	for (;;) {
		offsets = rec_get_offsets(cur.rec, index, offsets,
						ULINT_UNDEFINED, &heap);
		page_rec_print(cur.rec, offsets);

		if (count == pr_n) {
			break;
		}	
		if (page_cur_is_after_last(&cur)) {
			break;
		}	
		page_cur_move_to_next(&cur);
		count++;	
	}
	
	if (n_recs > 2 * pr_n) {
		fputs(" ... \n", stderr);
	}
	
	while (!page_cur_is_after_last(&cur)) {
		page_cur_move_to_next(&cur);

		if (count + pr_n >= n_recs) {	
			offsets = rec_get_offsets(cur.rec, index, offsets,
						ULINT_UNDEFINED, &heap);
			page_rec_print(cur.rec, offsets);
		}
		count++;	
	}

	fprintf(stderr,
		"Total of %lu records \n"
		"--------------------------------\n",
		(ulong) (count + 1));

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
}	

/*******************************************************************
Prints the info in a page header. */

void
page_header_print(
/*==============*/
	page_t*	page)
{
	fprintf(stderr,
		"--------------------------------\n"
		"PAGE HEADER INFO\n"
		"Page address %p, n records %lu (%s)\n"
		"n dir slots %lu, heap top %lu\n"
		"Page n heap %lu, free %lu, garbage %lu\n"
		"Page last insert %lu, direction %lu, n direction %lu\n",
		page, (ulong) page_header_get_field(page, PAGE_N_RECS),
		page_is_comp(page) ? "compact format" : "original format",
		(ulong) page_header_get_field(page, PAGE_N_DIR_SLOTS),
		(ulong) page_header_get_field(page, PAGE_HEAP_TOP),
		(ulong) page_dir_get_n_heap(page),
		(ulong) page_header_get_field(page, PAGE_FREE),
		(ulong) page_header_get_field(page, PAGE_GARBAGE),
		(ulong) page_header_get_field(page, PAGE_LAST_INSERT),
		(ulong) page_header_get_field(page, PAGE_DIRECTION),
		(ulong) page_header_get_field(page, PAGE_N_DIRECTION));
}

/*******************************************************************
This is used to print the contents of the page for
debugging purposes. */

void
page_print(
/*======*/
	page_t*		page,	/* in: index page */
	dict_index_t*	index,	/* in: dictionary index of the page */
	ulint		dn,	/* in: print dn first and last entries
				in directory */
	ulint		rn)	/* in: print rn first and last records
				in directory */
{
	page_header_print(page);
	page_dir_print(page, dn);
	page_print_list(page, index, rn);
}	

/*******************************************************************
The following is used to validate a record on a page. This function
differs from rec_validate as it can also check the n_owned field and
the heap_no field. */

ibool
page_rec_validate(
/*==============*/
				/* out: TRUE if ok */
	rec_t*		rec,	/* in: physical record */
	const ulint*	offsets)/* in: array returned by rec_get_offsets() */
{
	ulint	n_owned;
	ulint	heap_no;
	page_t*	page;
	ulint	comp;

	page = buf_frame_align(rec);
	comp = page_is_comp(page);
	ut_a(!comp == !rec_offs_comp(offsets));

	page_rec_check(rec);
	rec_validate(rec, offsets);

	n_owned = rec_get_n_owned(rec, comp);
	heap_no = rec_get_heap_no(rec, comp);

	if (!(n_owned <= PAGE_DIR_SLOT_MAX_N_OWNED)) {
		fprintf(stderr,
			"InnoDB: Dir slot of rec %lu, n owned too big %lu\n",
				(ulong)(rec - page), (ulong) n_owned);
		return(FALSE);
	}

	if (!(heap_no < page_dir_get_n_heap(page))) {
		fprintf(stderr,
		"InnoDB: Heap no of rec %lu too big %lu %lu\n",
				(ulong)(rec - page), (ulong) heap_no,
				(ulong) page_dir_get_n_heap(page));
		return(FALSE);
	}
	
	return(TRUE);
}

/*******************************************************************
Checks that the first directory slot points to the infimum record and
the last to the supremum. This function is intended to track if the
bug fixed in 4.0.14 has caused corruption to users' databases. */

void
page_check_dir(
/*===========*/
	page_t*	page)	/* in: index page */