page0page.ic

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

/******************************************************
Index page routines

(c) 1994-1996 Innobase Oy

Created 2/2/1994 Heikki Tuuri
*******************************************************/

#include "mach0data.h"
#include "rem0cmp.h"
#include "mtr0log.h"

#ifdef UNIV_MATERIALIZE
#undef UNIV_INLINE
#define UNIV_INLINE
#endif

/*****************************************************************
Returns the max trx id field value. */
UNIV_INLINE
dulint
page_get_max_trx_id(
/*================*/
	page_t*	page)	/* in: page */
{
	ut_ad(page);

	return(mach_read_from_8(page + PAGE_HEADER + PAGE_MAX_TRX_ID));
}

/*****************************************************************
Sets the max trx id field value if trx_id is bigger than the previous
value. */
UNIV_INLINE
void
page_update_max_trx_id(
/*===================*/
	page_t*	page,	/* in: page */
	dulint	trx_id)	/* in: transaction id */
{
	ut_ad(page);

	if (ut_dulint_cmp(page_get_max_trx_id(page), trx_id) < 0) {
	
		page_set_max_trx_id(page, trx_id);
	}
}

/*****************************************************************
Reads the given header field. */
UNIV_INLINE
ulint
page_header_get_field(
/*==================*/
	page_t*	page,	/* in: page */
	ulint	field)	/* in: PAGE_LEVEL, ... */
{
	ut_ad(page);
	ut_ad(field <= PAGE_INDEX_ID);

	return(mach_read_from_2(page + PAGE_HEADER + field));
}

/*****************************************************************
Sets the given header field. */
UNIV_INLINE
void
page_header_set_field(
/*==================*/
	page_t*	page,	/* in: page */
	ulint	field,	/* in: PAGE_LEVEL, ... */
	ulint	val)	/* in: value */
{
	ut_ad(page);
	ut_ad(field <= PAGE_N_RECS);
	ut_ad(field == PAGE_N_HEAP || val < UNIV_PAGE_SIZE);
	ut_ad(field != PAGE_N_HEAP || (val & 0x7fff) < UNIV_PAGE_SIZE);

	mach_write_to_2(page + PAGE_HEADER + field, val);
}

/*****************************************************************
Returns the pointer stored in the given header field. */
UNIV_INLINE
byte*
page_header_get_ptr(
/*================*/
			/* out: pointer or NULL */
	page_t*	page,	/* in: page */
	ulint	field)	/* in: PAGE_FREE, ... */
{
	ulint	offs;

	ut_ad(page);
	ut_ad((field == PAGE_FREE)
	      || (field == PAGE_LAST_INSERT)
	      || (field == PAGE_HEAP_TOP));

	offs = page_header_get_field(page, field);

	ut_ad((field != PAGE_HEAP_TOP) || offs);

	if (offs == 0) {

		return(NULL);
	}

	return(page + offs);
}

/*****************************************************************
Sets the pointer stored in the given header field. */
UNIV_INLINE
void
page_header_set_ptr(
/*================*/
	page_t*	page,	/* in: page */
	ulint	field,	/* in: PAGE_FREE, ... */
	byte*	ptr)	/* in: pointer or NULL*/
{
	ulint	offs;

	ut_ad(page);
	ut_ad((field == PAGE_FREE)
	      || (field == PAGE_LAST_INSERT)
	      || (field == PAGE_HEAP_TOP));

	if (ptr == NULL) {
		offs = 0;
	} else {
		offs = ptr - page;
	}

	ut_ad((field != PAGE_HEAP_TOP) || offs);

	page_header_set_field(page, field, offs);
}

/*****************************************************************
Resets the last insert info field in the page header. Writes to mlog
about this operation. */
UNIV_INLINE
void
page_header_reset_last_insert(
/*==========================*/
	page_t*	page,	/* in: page */
	mtr_t*	mtr)	/* in: mtr */
{
	ut_ad(page && mtr);

	mlog_write_ulint(page + PAGE_HEADER + PAGE_LAST_INSERT, 0,
							MLOG_2BYTES, mtr);
}

/****************************************************************
Determine whether the page is in new-style compact format. */
UNIV_INLINE
ulint
page_is_comp(
/*=========*/
			/* out: nonzero if the page is in compact
			format, zero if it is in old-style format */
	page_t*	page)	/* in: index page */
{
	return(UNIV_EXPECT(page_header_get_field(page, PAGE_N_HEAP) & 0x8000,
		0x8000));
}

/****************************************************************
TRUE if the record is on a page in compact format. */
UNIV_INLINE
ulint
page_rec_is_comp(
/*=============*/
				/* out: nonzero if in compact format */
	const rec_t*	rec)	/* in: record */
{
	return(page_is_comp(ut_align_down((rec_t*) rec, UNIV_PAGE_SIZE)));
}

/****************************************************************
Gets the first record on the page. */
UNIV_INLINE
rec_t*
page_get_infimum_rec(
/*=================*/
			/* out: the first record in record list */
	page_t*	page)	/* in: page which must have record(s) */
{
	ut_ad(page);

	if (page_is_comp(page)) {
		return(page + PAGE_NEW_INFIMUM);
	} else {
		return(page + PAGE_OLD_INFIMUM);
	}
}

/****************************************************************
Gets the last record on the page. */
UNIV_INLINE
rec_t*
page_get_supremum_rec(
/*==================*/
			/* out: the last record in record list */
	page_t*	page)	/* in: page which must have record(s) */
{
	ut_ad(page);

	if (page_is_comp(page)) {
		return(page + PAGE_NEW_SUPREMUM);
	} else {
		return(page + PAGE_OLD_SUPREMUM);
	}
}

/****************************************************************
TRUE if the record is a user record on the page. */
UNIV_INLINE
ibool
page_rec_is_user_rec_low(
/*=====================*/
			/* out: TRUE if a user record */
	ulint	offset)	/* in: record offset on page */
{
	ut_ad(offset >= PAGE_NEW_INFIMUM);
#if PAGE_OLD_INFIMUM < PAGE_NEW_INFIMUM
# error "PAGE_OLD_INFIMUM < PAGE_NEW_INFIMUM"
#endif
#if PAGE_OLD_SUPREMUM < PAGE_NEW_SUPREMUM
# error "PAGE_OLD_SUPREMUM < PAGE_NEW_SUPREMUM"
#endif
#if PAGE_NEW_INFIMUM > PAGE_OLD_SUPREMUM
# error "PAGE_NEW_INFIMUM > PAGE_OLD_SUPREMUM"
#endif
#if PAGE_OLD_INFIMUM > PAGE_NEW_SUPREMUM
# error "PAGE_OLD_INFIMUM > PAGE_NEW_SUPREMUM"
#endif
#if PAGE_NEW_SUPREMUM > PAGE_OLD_SUPREMUM_END
# error "PAGE_NEW_SUPREMUM > PAGE_OLD_SUPREMUM_END"
#endif
#if PAGE_OLD_SUPREMUM > PAGE_NEW_SUPREMUM_END
# error "PAGE_OLD_SUPREMUM > PAGE_NEW_SUPREMUM_END"
#endif
	ut_ad(offset <= UNIV_PAGE_SIZE - PAGE_EMPTY_DIR_START);

	return(UNIV_LIKELY(offset != PAGE_NEW_SUPREMUM)
		&& UNIV_LIKELY(offset != PAGE_NEW_INFIMUM)
		&& UNIV_LIKELY(offset != PAGE_OLD_INFIMUM)
		&& UNIV_LIKELY(offset != PAGE_OLD_SUPREMUM));
}

/****************************************************************
TRUE if the record is the supremum record on a page. */
UNIV_INLINE
ibool
page_rec_is_supremum_low(
/*=====================*/
			/* out: TRUE if the supremum record */
	ulint	offset)	/* in: record offset on page */
{
	ut_ad(offset >= PAGE_NEW_INFIMUM);
	ut_ad(offset <= UNIV_PAGE_SIZE - PAGE_EMPTY_DIR_START);

	return(UNIV_UNLIKELY(offset == PAGE_NEW_SUPREMUM)
		|| UNIV_UNLIKELY(offset == PAGE_OLD_SUPREMUM));
}

/****************************************************************
TRUE if the record is the infimum record on a page. */
UNIV_INLINE
ibool
page_rec_is_infimum_low(
/*=====================*/
			/* out: TRUE if the infimum record */
	ulint	offset)	/* in: record offset on page */
{
	ut_ad(offset >= PAGE_NEW_INFIMUM);
	ut_ad(offset <= UNIV_PAGE_SIZE - PAGE_EMPTY_DIR_START);

	return(UNIV_UNLIKELY(offset == PAGE_NEW_INFIMUM)
		|| UNIV_UNLIKELY(offset == PAGE_OLD_INFIMUM));
}

/****************************************************************
TRUE if the record is a user record on the page. */
UNIV_INLINE
ibool
page_rec_is_user_rec(
/*=================*/
				/* out: TRUE if a user record */
	const rec_t*	rec)	/* in: record */
{
	return(page_rec_is_user_rec_low(
			ut_align_offset(rec, UNIV_PAGE_SIZE)));
}

/****************************************************************
TRUE if the record is the supremum record on a page. */
UNIV_INLINE
ibool
page_rec_is_supremum(
/*=================*/
				/* out: TRUE if the supremum record */
	const rec_t*	rec)	/* in: record */
{
	return(page_rec_is_supremum_low(
			ut_align_offset(rec, UNIV_PAGE_SIZE)));
}

/****************************************************************
TRUE if the record is the infimum record on a page. */
UNIV_INLINE
ibool
page_rec_is_infimum(
/*================*/
				/* out: TRUE if the infimum record */
	const rec_t*	rec)	/* in: record */
{
	return(page_rec_is_infimum_low(
			ut_align_offset(rec, UNIV_PAGE_SIZE)));
}

/*****************************************************************
Compares a data tuple to a physical record. Differs from the function
cmp_dtuple_rec_with_match in the way that the record must reside on an
index page, and also page infimum and supremum records can be given in
the parameter rec. These are considered as the negative infinity and
the positive infinity in the alphabetical order. */
UNIV_INLINE
int
page_cmp_dtuple_rec_with_match(
/*===========================*/	
				/* out: 1, 0, -1, if dtuple is greater, equal, 
				less than rec, respectively, when only the 
				common first fields are compared */
	dtuple_t*	dtuple,	/* in: data tuple */
	rec_t*		rec,	/* in: physical record on a page; may also 
				be page infimum or supremum, in which case 
				matched-parameter values below are not 
				affected */
	const ulint*	offsets,/* in: array returned by rec_get_offsets() */
	ulint*	 	matched_fields, /* in/out: number of already completely 
				matched fields; when function returns
				contains the value for current comparison */
	ulint*	  	matched_bytes) /* in/out: number of already matched 
				bytes within the first field not completely
				matched; when function returns contains the
				value for current comparison */
{
	ulint	rec_offset;

	ut_ad(dtuple_check_typed(dtuple));
	ut_ad(rec_offs_validate(rec, NULL, offsets));
	ut_ad(!rec_offs_comp(offsets) == !page_rec_is_comp(rec));

	rec_offset = ut_align_offset(rec, UNIV_PAGE_SIZE);

	if (UNIV_UNLIKELY(rec_offset == PAGE_NEW_INFIMUM)
			|| UNIV_UNLIKELY(rec_offset == PAGE_OLD_INFIMUM)) {
		return(1);
	}
	if (UNIV_UNLIKELY(rec_offset == PAGE_NEW_SUPREMUM)
			|| UNIV_UNLIKELY(rec_offset == PAGE_OLD_SUPREMUM)) {
		return(-1);
	}

	return(cmp_dtuple_rec_with_match(dtuple, rec, offsets,
						matched_fields,
						matched_bytes));
}

/*****************************************************************
Gets the number of user records on page (infimum and supremum records
are not user records). */
UNIV_INLINE
ulint
page_get_n_recs(
/*============*/
			/* out: number of user records */
	page_t*	page)	/* in: index page */
{
	return(page_header_get_field(page, PAGE_N_RECS));
}

/*****************************************************************
Gets the number of dir slots in directory. */
UNIV_INLINE
ulint
page_dir_get_n_slots(
/*=================*/
			/* out: number of slots */
	page_t*	page)	/* in: index page */
{
	return(page_header_get_field(page, PAGE_N_DIR_SLOTS));
}
/*****************************************************************
Sets the number of dir slots in directory. */
UNIV_INLINE
void
page_dir_set_n_slots(
/*=================*/
			/* out: number of slots */
	page_t*	page,	/* in: index page */
	ulint	n_slots)/* in: number of slots */
{
	page_header_set_field(page, PAGE_N_DIR_SLOTS, n_slots);
}

/*****************************************************************
Gets the number of records in the heap. */
UNIV_INLINE
ulint
page_dir_get_n_heap(
/*================*/