rem0rec.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

/************************************************************************
Record manager

(c) 1994-1996 Innobase Oy

Created 5/30/1994 Heikki Tuuri
*************************************************************************/

#include "mach0data.h"
#include "ut0byte.h"
#include "dict0dict.h"

/* Compact flag ORed to the extra size returned by rec_get_offsets() */
#define REC_OFFS_COMPACT	((ulint) 1 << 31)
/* SQL NULL flag in offsets returned by rec_get_offsets() */
#define REC_OFFS_SQL_NULL	((ulint) 1 << 31)
/* External flag in offsets returned by rec_get_offsets() */
#define REC_OFFS_EXTERNAL	((ulint) 1 << 30)
/* Mask for offsets returned by rec_get_offsets() */
#define REC_OFFS_MASK		(REC_OFFS_EXTERNAL - 1)

/* Offsets of the bit-fields in an old-style record. NOTE! In the table the
most significant bytes and bits are written below less significant.

	(1) byte offset		(2) bit usage within byte
	downward from
	origin ->	1	8 bits pointer to next record
			2	8 bits pointer to next record
			3  	1 bit short flag
				7 bits number of fields
			4	3 bits number of fields
				5 bits heap number
			5	8 bits heap number
			6	4 bits n_owned
				4 bits info bits
*/

/* Offsets of the bit-fields in a new-style record. NOTE! In the table the
most significant bytes and bits are written below less significant.

	(1) byte offset		(2) bit usage within byte
	downward from
	origin ->	1	8 bits relative offset of next record
			2	8 bits relative offset of next record
				  the relative offset is an unsigned 16-bit
				  integer:
				  (offset_of_next_record
				   - offset_of_this_record) mod 64Ki,
				  where mod is the modulo as a non-negative
				  number;
				  we can calculate the the offset of the next
				  record with the formula:
				  relative_offset + offset_of_this_record
				  mod UNIV_PAGE_SIZE
			3	3 bits status:
					000=conventional record
					001=node pointer record (inside B-tree)
					010=infimum record
					011=supremum record
					1xx=reserved
				5 bits heap number
			4	8 bits heap number
			5	4 bits n_owned
				4 bits info bits
*/

/* We list the byte offsets from the origin of the record, the mask,
and the shift needed to obtain each bit-field of the record. */

#define REC_NEXT		2
#define REC_NEXT_MASK		0xFFFFUL
#define REC_NEXT_SHIFT		0

#define REC_OLD_SHORT		3	/* This is single byte bit-field */
#define REC_OLD_SHORT_MASK	0x1UL
#define REC_OLD_SHORT_SHIFT	0

#define REC_OLD_N_FIELDS	4
#define REC_OLD_N_FIELDS_MASK	0x7FEUL
#define REC_OLD_N_FIELDS_SHIFT	1

#define REC_NEW_STATUS		3	/* This is single byte bit-field */
#define REC_NEW_STATUS_MASK	0x7UL
#define REC_NEW_STATUS_SHIFT	0

#define REC_OLD_HEAP_NO		5
#define REC_NEW_HEAP_NO		4
#define REC_HEAP_NO_MASK	0xFFF8UL
#define	REC_HEAP_NO_SHIFT	3

#define REC_OLD_N_OWNED		6	/* This is single byte bit-field */
#define REC_NEW_N_OWNED		5	/* This is single byte bit-field */
#define	REC_N_OWNED_MASK	0xFUL
#define REC_N_OWNED_SHIFT	0

#define REC_OLD_INFO_BITS	6	/* This is single byte bit-field */
#define REC_NEW_INFO_BITS	5	/* This is single byte bit-field */
#define	REC_INFO_BITS_MASK	0xF0UL
#define REC_INFO_BITS_SHIFT	0

/* The deleted flag in info bits */
#define REC_INFO_DELETED_FLAG 	0x20UL	/* when bit is set to 1, it means the
					record has been delete marked */
/* The following masks are used to filter the SQL null bit from
one-byte and two-byte offsets */

#define REC_1BYTE_SQL_NULL_MASK	0x80UL
#define REC_2BYTE_SQL_NULL_MASK	0x8000UL

/* In a 2-byte offset the second most significant bit denotes
a field stored to another page: */

#define REC_2BYTE_EXTERN_MASK	0x4000UL

#if REC_OLD_SHORT_MASK << (8 * (REC_OLD_SHORT - 3)) \
		^ REC_OLD_N_FIELDS_MASK << (8 * (REC_OLD_N_FIELDS - 4)) \
		^ REC_HEAP_NO_MASK << (8 * (REC_OLD_HEAP_NO - 4)) \
		^ REC_N_OWNED_MASK << (8 * (REC_OLD_N_OWNED - 3)) \
		^ REC_INFO_BITS_MASK << (8 * (REC_OLD_INFO_BITS - 3)) \
		^ 0xFFFFFFFFUL
# error "sum of old-style masks != 0xFFFFFFFFUL"
#endif
#if REC_NEW_STATUS_MASK << (8 * (REC_NEW_STATUS - 3)) \
		^ REC_HEAP_NO_MASK << (8 * (REC_NEW_HEAP_NO - 4)) \
		^ REC_N_OWNED_MASK << (8 * (REC_NEW_N_OWNED - 3)) \
		^ REC_INFO_BITS_MASK << (8 * (REC_NEW_INFO_BITS - 3)) \
		^ 0xFFFFFFUL
# error "sum of new-style masks != 0xFFFFFFUL"
#endif

/***************************************************************
Sets the value of the ith field SQL null bit of an old-style record. */

void
rec_set_nth_field_null_bit(
/*=======================*/
	rec_t*	rec,	/* in: record */
	ulint	i,	/* in: ith field */
	ibool	val);	/* in: value to set */
/*************************************************************** 
Sets an old-style record field to SQL null.
The physical size of the field is not changed. */

void
rec_set_nth_field_sql_null(
/*=======================*/
	rec_t*	rec, 	/* in: record */
	ulint	n);	/* in: index of the field */

/***************************************************************
Sets the value of the ith field extern storage bit of an old-style record. */

void
rec_set_nth_field_extern_bit_old(
/*=============================*/
	rec_t*	rec,	/* in: old-style record */
	ulint	i,	/* in: ith field */
	ibool	val,	/* in: value to set */
	mtr_t*	mtr);	/* in: mtr holding an X-latch to the page where
			rec is, or NULL; in the NULL case we do not
			write to log about the change */
/***************************************************************
Sets the value of the ith field extern storage bit of a new-style record. */

void
rec_set_nth_field_extern_bit_new(
/*=============================*/
	rec_t*		rec,	/* in: record */
	dict_index_t*	index,	/* in: record descriptor */
	ulint		ith,	/* in: ith field */
	ibool		val,	/* in: value to set */
	mtr_t*		mtr);	/* in: mtr holding an X-latch to the page
				where rec is, or NULL; in the NULL case
				we do not write to log about the change */

/**********************************************************
Gets a bit field from within 1 byte. */
UNIV_INLINE
ulint
rec_get_bit_field_1(
/*================*/
	rec_t*	rec,	/* in: pointer to record origin */
	ulint	offs,	/* in: offset from the origin down */
	ulint	mask,	/* in: mask used to filter bits */
	ulint	shift)	/* in: shift right applied after masking */
{
	ut_ad(rec);

	return((mach_read_from_1(rec - offs) & mask) >> shift);
}

/**********************************************************
Sets a bit field within 1 byte. */
UNIV_INLINE
void
rec_set_bit_field_1(
/*================*/
	rec_t*	rec,	/* in: pointer to record origin */
	ulint	val,	/* in: value to set */
	ulint	offs,	/* in: offset from the origin down */
	ulint	mask,	/* in: mask used to filter bits */
	ulint	shift)	/* in: shift right applied after masking */
{
	ut_ad(rec);
	ut_ad(offs <= REC_N_OLD_EXTRA_BYTES);
	ut_ad(mask);
	ut_ad(mask <= 0xFFUL);
	ut_ad(((mask >> shift) << shift) == mask);
	ut_ad(((val << shift) & mask) == (val << shift));
	
	mach_write_to_1(rec - offs, 
			(mach_read_from_1(rec - offs) & ~mask) 
			| (val << shift));
}

/**********************************************************
Gets a bit field from within 2 bytes. */
UNIV_INLINE
ulint
rec_get_bit_field_2(
/*================*/
	rec_t*	rec,	/* in: pointer to record origin */
	ulint	offs,	/* in: offset from the origin down */
	ulint	mask,	/* in: mask used to filter bits */
	ulint	shift)	/* in: shift right applied after masking */
{
	ut_ad(rec);

	return((mach_read_from_2(rec - offs) & mask) >> shift);
}

/**********************************************************
Sets a bit field within 2 bytes. */
UNIV_INLINE
void
rec_set_bit_field_2(
/*================*/
	rec_t*	rec,	/* in: pointer to record origin */
	ulint	val,	/* in: value to set */
	ulint	offs,	/* in: offset from the origin down */
	ulint	mask,	/* in: mask used to filter bits */
	ulint	shift)	/* in: shift right applied after masking */
{
	ut_ad(rec);
	ut_ad(offs <= REC_N_OLD_EXTRA_BYTES);
	ut_ad(mask > 0xFFUL);
	ut_ad(mask <= 0xFFFFUL);
	ut_ad((mask >> shift) & 1);
	ut_ad(0 == ((mask >> shift) & ((mask >> shift) + 1)));
	ut_ad(((mask >> shift) << shift) == mask);
	ut_ad(((val << shift) & mask) == (val << shift));

	mach_write_to_2(rec - offs, 
			(mach_read_from_2(rec - offs) & ~mask) 
			| (val << shift));
}

/**********************************************************
The following function is used to get the offset of the next chained record
on the same page. */
UNIV_INLINE
ulint 
rec_get_next_offs(
/*==============*/
			/* out: the page offset of the next chained record, or
			0 if none */
	rec_t*	rec,	/* in: physical record */
	ulint	comp)	/* in: nonzero=compact page format */
{	
	ulint	field_value;
		
	ut_ad(REC_NEXT_MASK == 0xFFFFUL);
	ut_ad(REC_NEXT_SHIFT == 0);

	field_value = mach_read_from_2(rec - REC_NEXT);

	if (comp) {
#if UNIV_PAGE_SIZE <= 32768
		/* Note that for 64 KiB pages, field_value can 'wrap around'
		and the debug assertion is not valid */

		/* In the following assertion, field_value is interpreted
		as signed 16-bit integer in 2's complement arithmetics.
		If all platforms defined int16_t in the standard headers,
		the expression could be written simpler as
		(int16_t) field_value + ut_align_offset(...) < UNIV_PAGE_SIZE
		*/
		ut_ad((field_value >= 32768
			? field_value - 65536
			: field_value)
		       + ut_align_offset(rec, UNIV_PAGE_SIZE)
		      < UNIV_PAGE_SIZE);
#endif
		if (field_value == 0) {

			return(0);
		}
		
		return(ut_align_offset(rec + field_value, UNIV_PAGE_SIZE));
	} else {
		ut_ad(field_value < UNIV_PAGE_SIZE);

		return(field_value);
	}
}

/**********************************************************
The following function is used to set the next record offset field of the
record. */
UNIV_INLINE
void
rec_set_next_offs(
/*==============*/
	rec_t*	rec,	/* in: physical record */
	ulint	comp,	/* in: nonzero=compact page format */
	ulint	next)	/* in: offset of the next record, or 0 if none */
{
	ut_ad(rec);
	ut_ad(UNIV_PAGE_SIZE > next);
	ut_ad(REC_NEXT_MASK == 0xFFFFUL);
	ut_ad(REC_NEXT_SHIFT == 0);

	if (comp) {
		ulint field_value;

		if (next) {
			/* The following two statements calculate
			next - offset_of_rec mod 64Ki, where mod is the modulo
			as a non-negative number */
		
			field_value = (ulint)((lint)next 
				- (lint)ut_align_offset(rec, UNIV_PAGE_SIZE));
			field_value &= REC_NEXT_MASK;
		} else {
			field_value = 0;
		}

		mach_write_to_2(rec - REC_NEXT, field_value);
	} else {
		mach_write_to_2(rec - REC_NEXT, next);
	}
}

/**********************************************************
The following function is used to get the number of fields
in an old-style record. */
UNIV_INLINE
ulint
rec_get_n_fields_old(
/*=================*/
			/* out: number of data fields */
	rec_t*	rec)	/* in: physical record */
{
	ulint	ret;

	ut_ad(rec);

	ret = rec_get_bit_field_2(rec, REC_OLD_N_FIELDS,
				REC_OLD_N_FIELDS_MASK, REC_OLD_N_FIELDS_SHIFT);
	ut_ad(ret <= REC_MAX_N_FIELDS);
	ut_ad(ret > 0);

	return(ret);
}	

/**********************************************************
The following function is used to set the number of fields
in an old-style record. */
UNIV_INLINE
void
rec_set_n_fields_old(
/*=================*/
	rec_t*	rec,		/* in: physical record */
	ulint	n_fields)	/* in: the number of fields */
{
	ut_ad(rec);
	ut_ad(n_fields <= REC_MAX_N_FIELDS);
	ut_ad(n_fields > 0);

	rec_set_bit_field_2(rec, n_fields, REC_OLD_N_FIELDS,
		REC_OLD_N_FIELDS_MASK, REC_OLD_N_FIELDS_SHIFT);
}

/**********************************************************
The following function retrieves the status bits of a new-style record. */
UNIV_INLINE
ulint
rec_get_status(
/*===========*/
			/* out: status bits */
	rec_t*	rec)	/* in: physical record */
{
	ulint	ret;

	ut_ad(rec);

	ret = rec_get_bit_field_1(rec, REC_NEW_STATUS,
				REC_NEW_STATUS_MASK, REC_NEW_STATUS_SHIFT);
	ut_ad((ret & ~REC_NEW_STATUS_MASK) == 0);

	return(ret);
}

/**********************************************************
The following function is used to get the number of fields
in a record. */
UNIV_INLINE
ulint
rec_get_n_fields(
/*=============*/
				/* out: number of data fields */
	rec_t*		rec,	/* in: physical record */
	dict_index_t*	index)	/* in: record descriptor */
{
	ut_ad(rec);
	ut_ad(index);
	if (UNIV_UNLIKELY(!index->table->comp)) {
		return(rec_get_n_fields_old(rec));
	}
	switch (rec_get_status(rec)) {
	case REC_STATUS_ORDINARY:
		return(dict_index_get_n_fields(index));
	case REC_STATUS_NODE_PTR:
		return(dict_index_get_n_unique_in_tree(index) + 1);
	case REC_STATUS_INFIMUM:
	case REC_STATUS_SUPREMUM:
		return(1);
	default:
		ut_error;
		return(ULINT_UNDEFINED);
	}
}

/**********************************************************
The following function is used to get the number of records owned by the
previous directory record. */
UNIV_INLINE
ulint
rec_get_n_owned(
/*============*/
			/* out: number of owned records */
	rec_t*	rec,	/* in: physical record */
	ulint	comp)	/* in: nonzero=compact page format */
{
	ulint	ret;

	ut_ad(rec);

	ret = rec_get_bit_field_1(rec,
				comp ? REC_NEW_N_OWNED : REC_OLD_N_OWNED,
				REC_N_OWNED_MASK, REC_N_OWNED_SHIFT);
	ut_ad(ret <= REC_MAX_N_OWNED); 

	return(ret);
}	

/**********************************************************
The following function is used to set the number of owned records. */
UNIV_INLINE
void
rec_set_n_owned(
/*============*/
	rec_t*	rec,		/* in: physical record */
	ulint	comp,		/* in: nonzero=compact page format */
	ulint	n_owned)	/* in: the number of owned */
{
	ut_ad(rec);
	ut_ad(n_owned <= REC_MAX_N_OWNED);

	rec_set_bit_field_1(rec, n_owned,
				comp ? REC_NEW_N_OWNED : REC_OLD_N_OWNED,
				REC_N_OWNED_MASK, REC_N_OWNED_SHIFT);
}

/**********************************************************
The following function is used to retrieve the info bits of a record. */
UNIV_INLINE
ulint
rec_get_info_bits(
/*==============*/
			/* out: info bits */
	rec_t*	rec,	/* in: physical record */
	ulint	comp)	/* in: nonzero=compact page format */
{
	ulint	ret;

	ut_ad(rec);

	ret = rec_get_bit_field_1(rec,
				comp ? REC_NEW_INFO_BITS : REC_OLD_INFO_BITS,
				REC_INFO_BITS_MASK, REC_INFO_BITS_SHIFT);
	ut_ad((ret & ~REC_INFO_BITS_MASK) == 0);

	return(ret);
}	

/**********************************************************
The following function is used to set the info bits of a record. */
UNIV_INLINE
void
rec_set_info_bits(
/*==============*/
	rec_t*	rec,	/* in: physical record */
	ulint	comp,	/* in: nonzero=compact page format */
	ulint	bits)	/* in: info bits */