page0page.h

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
*******************************************************/

#ifndef page0page_h
#define page0page_h

#include "univ.i"

#include "page0types.h"
#include "fil0fil.h"
#include "buf0buf.h"
#include "data0data.h"
#include "dict0dict.h"
#include "rem0rec.h"
#include "fsp0fsp.h"
#include "mtr0mtr.h"

#ifdef UNIV_MATERIALIZE
#undef UNIV_INLINE
#define UNIV_INLINE
#endif

/*			PAGE HEADER
			===========

Index page header starts at the first offset left free by the FIL-module */

typedef	byte		page_header_t;

#define	PAGE_HEADER	FSEG_PAGE_DATA	/* index page header starts at this
				offset */
/*-----------------------------*/
#define PAGE_N_DIR_SLOTS 0	/* number of slots in page directory */
#define	PAGE_HEAP_TOP	 2	/* pointer to record heap top */
#define	PAGE_N_HEAP	 4	/* number of records in the heap,
				bit 15=flag: new-style compact page format */
#define	PAGE_FREE	 6	/* pointer to start of page free record list */
#define	PAGE_GARBAGE	 8	/* number of bytes in deleted records */
#define	PAGE_LAST_INSERT 10	/* pointer to the last inserted record, or
				NULL if this info has been reset by a delete,
				for example */
#define	PAGE_DIRECTION	 12	/* last insert direction: PAGE_LEFT, ... */
#define	PAGE_N_DIRECTION 14	/* number of consecutive inserts to the same
				direction */
#define	PAGE_N_RECS	 16	/* number of user records on the page */
#define PAGE_MAX_TRX_ID	 18	/* highest id of a trx which may have modified
				a record on the page; a dulint; defined only
				in secondary indexes; specifically, not in an
				ibuf tree; NOTE: this may be modified only
				when the thread has an x-latch to the page,
				and ALSO an x-latch to btr_search_latch
				if there is a hash index to the page! */
#define PAGE_HEADER_PRIV_END 26	/* end of private data structure of the page
				header which are set in a page create */
/*----*/
#define	PAGE_LEVEL	 26	/* level of the node in an index tree; the
				leaf level is the level 0 */
#define	PAGE_INDEX_ID	 28	/* index id where the page belongs */
#define PAGE_BTR_SEG_LEAF 36	/* file segment header for the leaf pages in
				a B-tree: defined only on the root page of a
				B-tree, but not in the root of an ibuf tree */
#define PAGE_BTR_IBUF_FREE_LIST	PAGE_BTR_SEG_LEAF
#define PAGE_BTR_IBUF_FREE_LIST_NODE PAGE_BTR_SEG_LEAF
				/* in the place of PAGE_BTR_SEG_LEAF and _TOP
				there is a free list base node if the page is
				the root page of an ibuf tree, and at the same
				place is the free list node if the page is in
				a free list */
#define PAGE_BTR_SEG_TOP (36 + FSEG_HEADER_SIZE)
				/* file segment header for the non-leaf pages
				in a B-tree: defined only on the root page of
				a B-tree, but not in the root of an ibuf
				tree */
/*----*/
#define PAGE_DATA	(PAGE_HEADER + 36 + 2 * FSEG_HEADER_SIZE)
				/* start of data on the page */

#define PAGE_OLD_INFIMUM	(PAGE_DATA + 1 + REC_N_OLD_EXTRA_BYTES)
				/* offset of the page infimum record on an
				old-style page */
#define PAGE_OLD_SUPREMUM	(PAGE_DATA + 2 + 2 * REC_N_OLD_EXTRA_BYTES + 8)
				/* offset of the page supremum record on an
				old-style page */
#define PAGE_OLD_SUPREMUM_END (PAGE_OLD_SUPREMUM + 9)
				/* offset of the page supremum record end on
				an old-style page */
#define PAGE_NEW_INFIMUM	(PAGE_DATA + REC_N_NEW_EXTRA_BYTES)
				/* offset of the page infimum record on a
				new-style compact page */
#define PAGE_NEW_SUPREMUM	(PAGE_DATA + 2 * REC_N_NEW_EXTRA_BYTES + 8)
				/* offset of the page supremum record on a
				new-style compact page */
#define PAGE_NEW_SUPREMUM_END (PAGE_NEW_SUPREMUM + 8)
				/* offset of the page supremum record end on
				a new-style compact page */
/*-----------------------------*/

/* Directions of cursor movement */
#define	PAGE_LEFT		1
#define	PAGE_RIGHT		2
#define	PAGE_SAME_REC		3
#define	PAGE_SAME_PAGE		4
#define	PAGE_NO_DIRECTION	5

/*			PAGE DIRECTORY
			==============
*/

typedef	byte			page_dir_slot_t;
typedef page_dir_slot_t		page_dir_t;

/* Offset of the directory start down from the page end. We call the
slot with the highest file address directory start, as it points to 
the first record in the list of records. */
#define	PAGE_DIR		FIL_PAGE_DATA_END

/* We define a slot in the page directory as two bytes */
#define	PAGE_DIR_SLOT_SIZE	2

/* The offset of the physically lower end of the directory, counted from
page end, when the page is empty */
#define PAGE_EMPTY_DIR_START	(PAGE_DIR + 2 * PAGE_DIR_SLOT_SIZE)

/* The maximum and minimum number of records owned by a directory slot. The
number may drop below the minimum in the first and the last slot in the 
directory. */
#define PAGE_DIR_SLOT_MAX_N_OWNED	8
#define	PAGE_DIR_SLOT_MIN_N_OWNED	4

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

void
page_set_max_trx_id(
/*================*/
	page_t*	page,	/* in: page */
	dulint	trx_id);/* in: transaction 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 */
/*****************************************************************
Reads the given header field. */
UNIV_INLINE
ulint
page_header_get_field(
/*==================*/
	page_t*	page,	/* in: page */
	ulint	field);	/* in: PAGE_N_DIR_SLOTS, ... */
/*****************************************************************
Sets the given header field. */
UNIV_INLINE
void
page_header_set_field(
/*==================*/
	page_t*	page,	/* in: page */
	ulint	field,	/* in: PAGE_N_DIR_SLOTS, ... */
	ulint	val);	/* in: value */
/*****************************************************************
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, ... */
/*****************************************************************
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*/
/*****************************************************************
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 */
/****************************************************************
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) */
/****************************************************************
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) */
/****************************************************************
Returns the middle record of record list. If there are an even number
of records in the list, returns the first record of upper half-list. */

rec_t*
page_get_middle_rec(
/*================*/
			/* out: middle record */
	page_t*	page);	/* in: page */
/*****************************************************************
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 */
/*****************************************************************
Gets the number of user records on page (the 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 */
/*******************************************************************
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 */
/*****************************************************************
Gets the number of records in the heap. */
UNIV_INLINE
ulint
page_dir_get_n_heap(
/*================*/
			/* out: number of user records */
	page_t*	page);	/* in: index page */
/*****************************************************************
Sets the number of records in the heap. */
UNIV_INLINE
void
page_dir_set_n_heap(
/*================*/
	page_t*	page,	/* in: index page */
	ulint	n_heap);/* in: number of records */
/*****************************************************************
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 */
/*****************************************************************
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 */
/*****************************************************************
Gets pointer to nth directory slot. */
UNIV_INLINE
page_dir_slot_t*
page_dir_get_nth_slot(
/*==================*/
			/* out: pointer to dir slot */
	page_t*	page,	/* in: index page */
	ulint	n);	/* in: position */
/******************************************************************
Used to check the consistency of a record on a page. */
UNIV_INLINE
ibool
page_rec_check(
/*===========*/
			/* out: TRUE if succeed */
	rec_t*	rec);	/* in: record */
/*******************************************************************
Gets the record pointed to by a directory slot. */
UNIV_INLINE
rec_t*
page_dir_slot_get_rec(
/*==================*/
					/* out: pointer to record */
	page_dir_slot_t*	slot);	/* in: directory slot */
/*******************************************************************
This is used to set the record offset in a directory slot. */
UNIV_INLINE
void
page_dir_slot_set_rec(
/*==================*/
	page_dir_slot_t* slot,	/* in: directory slot */
	rec_t*		 rec);	/* in: record on the page */
/*******************************************************************
Gets the number of records owned by a directory slot. */
UNIV_INLINE
ulint
page_dir_slot_get_n_owned(
/*======================*/
					/* out: number of records */
	page_dir_slot_t* 	slot);	/* in: page directory slot */
/*******************************************************************
This is used to set the owned records field of a directory slot. */
UNIV_INLINE
void
page_dir_slot_set_n_owned(
/*======================*/
	page_dir_slot_t*	slot,	/* in: directory slot */
	ulint			n);	/* in: number of records owned 
					by the slot */
/****************************************************************
Calculates the space reserved for directory slots of a given
number of records. The exact value is a fraction number
n * PAGE_DIR_SLOT_SIZE / PAGE_DIR_SLOT_MIN_N_OWNED, and it is
rounded upwards to an integer. */
UNIV_INLINE
ulint
page_dir_calc_reserved_space(
/*=========================*/
	ulint	n_recs);	/* in: number of records */
/*******************************************************************
Looks for the directory slot which owns the given record. */

ulint
page_dir_find_owner_slot(
/*=====================*/
				/* out: the directory slot number */
	rec_t*		rec);	/* in: the physical record */
/****************************************************************
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 */
/****************************************************************
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 */
/****************************************************************
Gets the pointer to the next record on the page. */
UNIV_INLINE
rec_t*
page_rec_get_next(
/*==============*/
			/* out: pointer to next record */
	rec_t*	rec);	/* in: pointer to record, must not be page
			supremum */
/****************************************************************
Sets the pointer to the next record on the page. */ 
UNIV_INLINE
void