path: root/storage/xtradb/include/rem0rec.ic

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

Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA

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

/********************************************************************//**
@file include/rem0rec.ic
Record manager

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

#include "mach0data.h"
#include "ut0byte.h"
#include "dict0dict.h"
#include "btr0types.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 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_HEAP_NO_MASK	0xFFF8UL
#if 0 /* defined in rem0rec.h for use of page0zip.cc */
#define REC_NEW_HEAP_NO		4
#define	REC_HEAP_NO_SHIFT	3
#endif

#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

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

/******************************************************//**
Gets a bit field from within 1 byte. */
UNIV_INLINE
ulint
rec_get_bit_field_1(
/*================*/
	const 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(
/*================*/
	const 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 pointer of the next chained record
on the same page.
@return	pointer to the next chained record, or NULL if none */
UNIV_INLINE
const rec_t*
rec_get_next_ptr_const(
/*===================*/
	const 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 (field_value == 0) {

		return(NULL);
	}

	if (comp) {
#if UNIV_PAGE_SIZE_MAX <= 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
		/* There must be at least REC_N_NEW_EXTRA_BYTES + 1
		between each record. */
		ut_ad((field_value > REC_N_NEW_EXTRA_BYTES
		       && field_value < 32768)
		      || field_value < (uint16) -REC_N_NEW_EXTRA_BYTES);

		return((byte*) ut_align_down(rec, UNIV_PAGE_SIZE)
		       + ut_align_offset(rec + field_value, UNIV_PAGE_SIZE));
	} else {
		ut_ad(field_value < UNIV_PAGE_SIZE);

		return((byte*) ut_align_down(rec, UNIV_PAGE_SIZE)
		       + field_value);
	}
}

/******************************************************//**
The following function is used to get the pointer of the next chained record
on the same page.
@return	pointer to the next chained record, or NULL if none */
UNIV_INLINE
rec_t*
rec_get_next_ptr(
/*=============*/
	rec_t*	rec,	/*!< in: physical record */
	ulint	comp)	/*!< in: nonzero=compact page format */
{
	return(const_cast<rec_t*>(rec_get_next_ptr_const(rec, comp)));
}

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

	field_value = mach_read_from_2(rec - REC_NEXT);

	if (comp) {
#if UNIV_PAGE_SIZE_MAX <= 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);
		}

		/* There must be at least REC_N_NEW_EXTRA_BYTES + 1
		between each record. */
		ut_ad((field_value > REC_N_NEW_EXTRA_BYTES
		       && field_value < 32768)
		      || field_value < (uint16) -REC_N_NEW_EXTRA_BYTES);

		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 an old-style record. */
UNIV_INLINE
void
rec_set_next_offs_old(
/*==================*/
	rec_t*	rec,	/*!< in: old-style physical record */
	ulint	next)	/*!< in: offset of the next record */
{
	ut_ad(rec);
	ut_ad(UNIV_PAGE_SIZE > next);
#if REC_NEXT_MASK != 0xFFFFUL
# error "REC_NEXT_MASK != 0xFFFFUL"
#endif
#if REC_NEXT_SHIFT
# error "REC_NEXT_SHIFT != 0"
#endif

	mach_write_to_2(rec - REC_NEXT, next);
}

/******************************************************//**
The following function is used to set the next record offset field
of a new-style record. */
UNIV_INLINE
void
rec_set_next_offs_new(
/*==================*/
	rec_t*	rec,	/*!< in/out: new-style physical record */
	ulint	next)	/*!< in: offset of the next record */
{
	ulint	field_value;

	ut_ad(rec);
	ut_ad(UNIV_PAGE_SIZE > next);

	if (!next) {
		field_value = 0;
	} else {
		/* 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;
	}

	mach_write_to_2(rec - REC_NEXT, field_value);
}

/******************************************************//**
The following function is used to get the number of fields
in an old-style record.
@return	number of data fields */
UNIV_INLINE
ulint
rec_get_n_fields_old(
/*=================*/
	const 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.
@return	status bits */
UNIV_INLINE
ulint
rec_get_status(
/*===========*/
	const 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.
@return	number of data fields */
UNIV_INLINE
ulint
rec_get_n_fields(
/*=============*/
	const rec_t*		rec,	/*!< in: physical record */
	const dict_index_t*	index)	/*!< in: record descriptor */
{
	ut_ad(rec);
	ut_ad(index);

	if (!dict_table_is_comp(index->table)) {
		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.
@return	number of owned records */
UNIV_INLINE
ulint
rec_get_n_owned_old(
/*================*/
	const rec_t*	rec)	/*!< in: old-style physical record */
{
	return(rec_get_bit_field_1(rec, REC_OLD_N_OWNED,
				   REC_N_OWNED_MASK, REC_N_OWNED_SHIFT));
}

/******************************************************//**
The following function is used to set the number of owned records. */
UNIV_INLINE
void
rec_set_n_owned_old(
/*================*/
	rec_t*	rec,		/*!< in: old-style physical record */
	ulint	n_owned)	/*!< in: the number of owned */
{
	rec_set_bit_field_1(rec, n_owned, REC_OLD_N_OWNED,
			    REC_N_OWNED_MASK, REC_N_OWNED_SHIFT);
}

/******************************************************//**
The following function is used to get the number of records owned by the
previous directory record.
@return	number of owned records */
UNIV_INLINE
ulint
rec_get_n_owned_new(
/*================*/
	const rec_t*	rec)	/*!< in: new-style physical record */
{
	return(rec_get_bit_field_1(rec, REC_NEW_N_OWNED,
				   REC_N_OWNED_MASK, REC_N_OWNED_SHIFT));
}

/******************************************************//**
The following function is used to set the number of owned records. */
UNIV_INLINE
void
rec_set_n_owned_new(
/*================*/
	rec_t*		rec,	/*!< in/out: new-style physical record */
	page_zip_des_t*	page_zip,/*!< in/out: compressed page, or NULL */
	ulint		n_owned)/*!< in: the number of owned */
{
	rec_set_bit_field_1(rec, n_owned, REC_NEW_N_OWNED,
			    REC_N_OWNED_MASK, REC_N_OWNED_SHIFT);
	if (page_zip && rec_get_status(rec) != REC_STATUS_SUPREMUM) {
		page_zip_rec_set_owned(page_zip, rec, n_owned);
	}
}

/******************************************************//**
The following function is used to retrieve the info bits of a record.
@return	info bits */
UNIV_INLINE
ulint
rec_get_info_bits(
/*==============*/
	const rec_t*	rec,	/*!< in: physical record */
	ulint		comp)	/*!< in: nonzero=compact page format */
{
	return(rec_get_bit_field_1(
		       rec, comp ? REC_NEW_INFO_BITS : REC_OLD_INFO_BITS,
		       REC_INFO_BITS_MASK, REC_INFO_BITS_SHIFT));
}

/******************************************************//**
The following function is used to set the info bits of a record. */
UNIV_INLINE
void
rec_set_info_bits_old(
/*==================*/
	rec_t*	rec,	/*!< in: old-style physical record */
	ulint	bits)	/*!< in: info bits */
{
	rec_set_bit_field_1(rec, bits, REC_OLD_INFO_BITS,
			    REC_INFO_BITS_MASK, REC_INFO_BITS_SHIFT);
}
/******************************************************//**
The following function is used to set the info bits of a record. */
UNIV_INLINE
void
rec_set_info_bits_new(
/*==================*/
	rec_t*	rec,	/*!< in/out: new-style physical record */
	ulint	bits)	/*!< in: info bits */
{
	rec_set_bit_field_1(rec, bits, REC_NEW_INFO_BITS,
			    REC_INFO_BITS_MASK, REC_INFO_BITS_SHIFT);
}

/******************************************************//**
The following function is used to set the status bits of a new-style record. */
UNIV_INLINE
void
rec_set_status(
/*===========*/
	rec_t*	rec,	/*!< in/out: physical record */
	ulint	bits)	/*!< in: info bits */
{
	rec_set_bit_field_1(rec, bits, REC_NEW_STATUS,
			    REC_NEW_STATUS_MASK, REC_NEW_STATUS_SHIFT);
}

/******************************************************//**
The following function is used to retrieve the info and status
bits of a record.  (Only compact records have status bits.)
@return	info bits */
UNIV_INLINE
ulint
rec_get_info_and_status_bits(
/*=========================*/
	const rec_t*	rec,	/*!< in: physical record */
	ulint		comp)	/*!< in: nonzero=compact page format */
{
	ulint	bits;
#if (REC_NEW_STATUS_MASK >> REC_NEW_STATUS_SHIFT) \
& (REC_INFO_BITS_MASK >> REC_INFO_BITS_SHIFT)
# error "REC_NEW_STATUS_MASK and REC_INFO_BITS_MASK overlap"
#endif
	if (comp) {
		bits = rec_get_info_bits(rec, TRUE) | rec_get_status(rec);
	} else {
		bits = rec_get_info_bits(rec, FALSE);
		ut_ad(!(bits & ~(REC_INFO_BITS_MASK >> REC_INFO_BITS_SHIFT)));
	}
	return(bits);
}
/******************************************************//**
The following function is used to set the info and status
bits of a record.  (Only compact records have status bits.) */
UNIV_INLINE
void
rec_set_info_and_status_bits(
/*=========================*/
	rec_t*	rec,	/*!< in/out: physical record */
	ulint	bits)	/*!< in: info bits */
{
#if (REC_NEW_STATUS_MASK >> REC_NEW_STATUS_SHIFT) \
& (REC_INFO_BITS_MASK >> REC_INFO_BITS_SHIFT)
# error "REC_NEW_STATUS_MASK and REC_INFO_BITS_MASK overlap"
#endif
	rec_set_status(rec, bits & REC_NEW_STATUS_MASK);
	rec_set_info_bits_new(rec, bits & ~REC_NEW_STATUS_MASK);
}

/******************************************************//**
The following function tells if record is delete marked.
@return	nonzero if delete marked */
UNIV_INLINE
ulint
rec_get_deleted_flag(
/*=================*/
	const rec_t*	rec,	/*!< in: physical record */
	ulint		comp)	/*!< in: nonzero=compact page format */
{
	if (comp) {
		return(rec_get_bit_field_1(rec, REC_NEW_INFO_BITS,
					   REC_INFO_DELETED_FLAG,
					   REC_INFO_BITS_SHIFT));
	} else {
		return(rec_get_bit_field_1(rec, REC_OLD_INFO_BITS,
					   REC_INFO_DELETED_FLAG,
					   REC_INFO_BITS_SHIFT));
	}
}

/******************************************************//**
The following function is used to set the deleted bit. */
UNIV_INLINE
void
rec_set_deleted_flag_old(
/*=====================*/
	rec_t*	rec,	/*!< in: old-style physical record */
	ulint	flag)	/*!< in: nonzero if delete marked */
{
	ulint	val;

	val = rec_get_info_bits(rec, FALSE);

	if (flag) {
		val |= REC_INFO_DELETED_FLAG;
	} else {
		val &= ~REC_INFO_DELETED_FLAG;
	}

	rec_set_info_bits_old(rec, val);
}

/******************************************************//**
The following function is used to set the deleted bit. */
UNIV_INLINE
void
rec_set_deleted_flag_new(
/*=====================*/
	rec_t*		rec,	/*!< in/out: new-style physical record */
	page_zip_des_t*	page_zip,/*!< in/out: compressed page, or NULL */
	ulint		flag)	/*!< in: nonzero if delete marked */
{
	ulint	val;

	val = rec_get_info_bits(rec, TRUE);

	if (flag) {
		val |= REC_INFO_DELETED_FLAG;
	} else {
		val &= ~REC_INFO_DELETED_FLAG;
	}

	rec_set_info_bits_new(rec, val);

	if (page_zip) {
		page_zip_rec_set_deleted(page_zip, rec, flag);
	}
}

/******************************************************//**
The following function tells if a new-style record is a node pointer.
@return	TRUE if node pointer */
UNIV_INLINE
ibool
rec_get_node_ptr_flag(
/*==================*/
	const rec_t*	rec)	/*!< in: physical record */
{
	return(REC_STATUS_NODE_PTR == rec_get_status(rec));
}

/******************************************************//**
The following function is used to get the order number
of an old-style record in the heap of the index page.
@return	heap order number */
UNIV_INLINE
ulint
rec_get_heap_no_old(
/*================*/
	const rec_t*	rec)	/*!< in: physical record */
{
	return(rec_get_bit_field_2(rec, REC_OLD_HEAP_NO,
				   REC_HEAP_NO_MASK, REC_HEAP_NO_SHIFT));
}

/******************************************************//**
The following function is used to set the heap number
field in an old-style record. */
UNIV_INLINE
void
rec_set_heap_no_old(
/*================*/
	rec_t*	rec,	/*!< in: physical record */
	ulint	heap_no)/*!< in: the heap number */
{
	rec_set_bit_field_2(rec, heap_no, REC_OLD_HEAP_NO,
			    REC_HEAP_NO_MASK, REC_HEAP_NO_SHIFT);
}

/******************************************************//**
The following function is used to get the order number
of a new-style record in the heap of the index page.
@return	heap order number */
UNIV_INLINE
ulint
rec_get_heap_no_new(
/*================*/
	const rec_t*	rec)	/*!< in: physical record */
{
	return(rec_get_bit_field_2(rec, REC_NEW_HEAP_NO,
				   REC_HEAP_NO_MASK, REC_HEAP_NO_SHIFT));
}

/******************************************************//**
The following function is used to set the heap number
field in a new-style record. */
UNIV_INLINE
void
rec_set_heap_no_new(
/*================*/
	rec_t*	rec,	/*!< in/out: physical record */
	ulint	heap_no)/*!< in: the heap number */
{
	rec_set_bit_field_2(rec, heap_no, REC_NEW_HEAP_NO,
			    REC_HEAP_NO_MASK, REC_HEAP_NO_SHIFT);
}

/******************************************************//**
The following function is used to test whether the data offsets in the record
are stored in one-byte or two-byte format.
@return	TRUE if 1-byte form */
UNIV_INLINE
ibool
rec_get_1byte_offs_flag(
/*====================*/
	const rec_t*	rec)	/*!< in: physical record */
{
#if TRUE != 1
#error "TRUE != 1"
#endif

	return(rec_get_bit_field_1(rec, REC_OLD_SHORT, REC_OLD_SHORT_MASK,
				   REC_OLD_SHORT_SHIFT));
}

/******************************************************//**
The following function is used to set the 1-byte offsets flag. */
UNIV_INLINE
void
rec_set_1byte_offs_flag(
/*====================*/
	rec_t*	rec,	/*!< in: physical record */
	ibool	flag)	/*!< in: TRUE if 1byte form */
{
#if TRUE != 1
#error "TRUE != 1"
#endif
	ut_ad(flag <= TRUE);

	rec_set_bit_field_1(rec, flag, REC_OLD_SHORT, REC_OLD_SHORT_MASK,
			    REC_OLD_SHORT_SHIFT);
}

/******************************************************//**
Returns the offset of nth field end if the record is stored in the 1-byte
offsets form. If the field is SQL null, the flag is ORed in the returned
value.
@return	offset of the start of the field, SQL null flag ORed */
UNIV_INLINE
ulint
rec_1_get_field_end_info(
/*=====================*/
	const rec_t*	rec,	/*!< in: record */
	ulint		n)	/*!< in: field index */
{
	ut_ad(rec_get_1byte_offs_flag(rec));
	ut_ad(n < rec_get_n_fields_old(rec));

	return(mach_read_from_1(rec - (REC_N_OLD_EXTRA_BYTES + n + 1)));
}

/******************************************************//**
Returns the offset of nth field end if the record is stored in the 2-byte
offsets form. If the field is SQL null, the flag is ORed in the returned
value.
@return offset of the start of the field, SQL null flag and extern
storage flag ORed */
UNIV_INLINE
ulint
rec_2_get_field_end_info(
/*=====================*/
	const rec_t*	rec,	/*!< in: record */
	ulint		n)	/*!< in: field index */
{
	ut_ad(!rec_get_1byte_offs_flag(rec));
	ut_ad(n < rec_get_n_fields_old(rec));

	return(mach_read_from_2(rec - (REC_N_OLD_EXTRA_BYTES + 2 * n + 2)));
}

/******************************************************//**
Returns nonzero if the field is stored off-page.
@retval 0 if the field is stored in-page
@retval REC_2BYTE_EXTERN_MASK if the field is stored externally */
UNIV_INLINE
ulint
rec_2_is_field_extern(
/*==================*/
	const rec_t*	rec,	/*!< in: record */
	ulint		n)	/*!< in: field index */
{
	return(rec_2_get_field_end_info(rec, n) & REC_2BYTE_EXTERN_MASK);
}

/* Get the base address of offsets.  The extra_size is stored at
this position, and following positions hold the end offsets of
the fields. */
#define rec_offs_base(offsets) (offsets + REC_OFFS_HEADER_SIZE)

/**********************************************************//**
The following function returns the number of allocated elements
for an array of offsets.
@return	number of elements */
UNIV_INLINE
ulint
rec_offs_get_n_alloc(
/*=================*/
	const ulint*	offsets)/*!< in: array for rec_get_offsets() */
{
	ulint	n_alloc;
	ut_ad(offsets);
	n_alloc = offsets[0];
	ut_ad(n_alloc > REC_OFFS_HEADER_SIZE);
	UNIV_MEM_ASSERT_W(offsets, n_alloc * sizeof *offsets);
	return(n_alloc);
}

/**********************************************************//**
The following function sets the number of allocated elements
for an array of offsets. */
UNIV_INLINE
void
rec_offs_set_n_alloc(
/*=================*/
	ulint*	offsets,	/*!< out: array for rec_get_offsets(),
				must be allocated */
	ulint	n_alloc)	/*!< in: number of elements */
{
	ut_ad(offsets);
	ut_ad(n_alloc > REC_OFFS_HEADER_SIZE);
	UNIV_MEM_ASSERT_AND_ALLOC(offsets, n_alloc * sizeof *offsets);
	offsets[0] = n_alloc;
}

/**********************************************************//**
The following function returns the number of fields in a record.
@return	number of fields */
UNIV_INLINE
ulint
rec_offs_n_fields(
/*==============*/
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	ulint	n_fields;
	ut_ad(offsets);
	n_fields = offsets[1];
	ut_ad(n_fields > 0);
	ut_ad(n_fields <= REC_MAX_N_FIELDS);
	ut_ad(n_fields + REC_OFFS_HEADER_SIZE
	      <= rec_offs_get_n_alloc(offsets));
	return(n_fields);
}

/************************************************************//**
Validates offsets returned by rec_get_offsets().
@return	TRUE if valid */
UNIV_INLINE
ibool
rec_offs_validate(
/*==============*/
	const rec_t*		rec,	/*!< in: record or NULL */
	const dict_index_t*	index,	/*!< in: record descriptor or NULL */
	const ulint*		offsets)/*!< in: array returned by
					rec_get_offsets() */
{
	ulint	i	= rec_offs_n_fields(offsets);
	ulint	last	= ULINT_MAX;
	ulint	comp	= *rec_offs_base(offsets) & REC_OFFS_COMPACT;

	if (rec) {
		ut_ad((ulint) rec == offsets[2]);
		if (!comp) {
			ut_a(rec_get_n_fields_old(rec) >= i);
		}
	}
	if (index) {
		ulint max_n_fields;
		ut_ad((ulint) index == offsets[3]);
		max_n_fields = ut_max(
			dict_index_get_n_fields(index),
			dict_index_get_n_unique_in_tree(index) + 1);
		if (comp && rec) {
			switch (rec_get_status(rec)) {
			case REC_STATUS_ORDINARY:
				break;
			case REC_STATUS_NODE_PTR:
				max_n_fields = dict_index_get_n_unique_in_tree(
					index) + 1;
				break;
			case REC_STATUS_INFIMUM:
			case REC_STATUS_SUPREMUM:
				max_n_fields = 1;
				break;
			default:
				ut_error;
			}
		}
		/* index->n_def == 0 for dummy indexes if !comp */
		ut_a(!comp || index->n_def);
		ut_a(!index->n_def || i <= max_n_fields);
	}
	while (i--) {
		ulint	curr = rec_offs_base(offsets)[1 + i] & REC_OFFS_MASK;
		ut_a(curr <= last);
		last = curr;
	}
	return(TRUE);
}
#ifdef UNIV_DEBUG
/************************************************************//**
Updates debug data in offsets, in order to avoid bogus
rec_offs_validate() failures. */
UNIV_INLINE
void
rec_offs_make_valid(
/*================*/
	const rec_t*		rec,	/*!< in: record */
	const dict_index_t*	index,	/*!< in: record descriptor */
	ulint*			offsets)/*!< in: array returned by
					rec_get_offsets() */
{
	ut_ad(rec);
	ut_ad(index);
	ut_ad(offsets);
	ut_ad(rec_get_n_fields(rec, index) >= rec_offs_n_fields(offsets));
	offsets[2] = (ulint) rec;
	offsets[3] = (ulint) index;
}
#endif /* UNIV_DEBUG */

/************************************************************//**
The following function is used to get an offset to the nth
data field in a record.
@return	offset from the origin of rec */
UNIV_INLINE
ulint
rec_get_nth_field_offs(
/*===================*/
	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
	ulint		n,	/*!< in: index of the field */
	ulint*		len)	/*!< out: length of the field; UNIV_SQL_NULL
				if SQL null */
{
	ulint	offs;
	ulint	length;
	ut_ad(n < rec_offs_n_fields(offsets));
	ut_ad(len);

	if (n == 0) {
		offs = 0;
	} else {
		offs = rec_offs_base(offsets)[n] & REC_OFFS_MASK;
	}

	length = rec_offs_base(offsets)[1 + n];

	if (length & REC_OFFS_SQL_NULL) {
		length = UNIV_SQL_NULL;
	} else {
		length &= REC_OFFS_MASK;
		length -= offs;
	}

	*len = length;
	return(offs);
}

/******************************************************//**
Determine if the offsets are for a record in the new
compact format.
@return	nonzero if compact format */
UNIV_INLINE
ulint
rec_offs_comp(
/*==========*/
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	ut_ad(rec_offs_validate(NULL, NULL, offsets));
	return(*rec_offs_base(offsets) & REC_OFFS_COMPACT);
}

/******************************************************//**
Determine if the offsets are for a record containing
externally stored columns.
@return	nonzero if externally stored */
UNIV_INLINE
ulint
rec_offs_any_extern(
/*================*/
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	ut_ad(rec_offs_validate(NULL, NULL, offsets));
	return(*rec_offs_base(offsets) & REC_OFFS_EXTERNAL);
}

/******************************************************//**
Determine if the offsets are for a record containing null BLOB pointers.
@return	first field containing a null BLOB pointer, or NULL if none found */
UNIV_INLINE
const byte*
rec_offs_any_null_extern(
/*=====================*/
	const rec_t*	rec,		/*!< in: record */
	const ulint*	offsets)	/*!< in: rec_get_offsets(rec) */
{
	ulint	i;
	ut_ad(rec_offs_validate(rec, NULL, offsets));

	if (!rec_offs_any_extern(offsets)) {
		return(NULL);
	}

	for (i = 0; i < rec_offs_n_fields(offsets); i++) {
		if (rec_offs_nth_extern(offsets, i)) {
			ulint		len;
			const byte*	field
				= rec_get_nth_field(rec, offsets, i, &len);

			ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
			if (!memcmp(field + len
				    - BTR_EXTERN_FIELD_REF_SIZE,
				    field_ref_zero,
				    BTR_EXTERN_FIELD_REF_SIZE)) {
				return(field);
			}
		}
	}

	return(NULL);
}

/******************************************************//**
Returns nonzero if the extern bit is set in nth field of rec.
@return	nonzero if externally stored */
UNIV_INLINE
ulint
rec_offs_nth_extern(
/*================*/
	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
	ulint		n)	/*!< in: nth field */
{
	ut_ad(rec_offs_validate(NULL, NULL, offsets));
	ut_ad(n < rec_offs_n_fields(offsets));
	return(rec_offs_base(offsets)[1 + n] & REC_OFFS_EXTERNAL);
}

/******************************************************//**
Returns nonzero if the SQL NULL bit is set in nth field of rec.
@return	nonzero if SQL NULL */
UNIV_INLINE
ulint
rec_offs_nth_sql_null(
/*==================*/
	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
	ulint		n)	/*!< in: nth field */
{
	ut_ad(rec_offs_validate(NULL, NULL, offsets));
	ut_ad(n < rec_offs_n_fields(offsets));
	return(rec_offs_base(offsets)[1 + n] & REC_OFFS_SQL_NULL);
}

/******************************************************//**
Gets the physical size of a field.
@return	length of field */
UNIV_INLINE
ulint
rec_offs_nth_size(
/*==============*/
	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
	ulint		n)	/*!< in: nth field */
{
	ut_ad(rec_offs_validate(NULL, NULL, offsets));
	ut_ad(n < rec_offs_n_fields(offsets));
	if (!n) {
		return(rec_offs_base(offsets)[1 + n] & REC_OFFS_MASK);
	}
	return((rec_offs_base(offsets)[1 + n] - rec_offs_base(offsets)[n])
	       & REC_OFFS_MASK);
}

/******************************************************//**
Returns the number of extern bits set in a record.
@return	number of externally stored fields */
UNIV_INLINE
ulint
rec_offs_n_extern(
/*==============*/
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	ulint	n = 0;

	if (rec_offs_any_extern(offsets)) {
		ulint	i;

		for (i = rec_offs_n_fields(offsets); i--; ) {
			if (rec_offs_nth_extern(offsets, i)) {
				n++;
			}
		}
	}

	return(n);
}

/******************************************************//**
Returns the offset of n - 1th field end if the record is stored in the 1-byte
offsets form. If the field is SQL null, the flag is ORed in the returned
value. This function and the 2-byte counterpart are defined here because the
C-compiler was not able to sum negative and positive constant offsets, and
warned of constant arithmetic overflow within the compiler.
@return	offset of the start of the PREVIOUS field, SQL null flag ORed */
UNIV_INLINE
ulint
rec_1_get_prev_field_end_info(
/*==========================*/
	const rec_t*	rec,	/*!< in: record */
	ulint		n)	/*!< in: field index */
{
	ut_ad(rec_get_1byte_offs_flag(rec));
	ut_ad(n <= rec_get_n_fields_old(rec));

	return(mach_read_from_1(rec - (REC_N_OLD_EXTRA_BYTES + n)));
}

/******************************************************//**
Returns the offset of n - 1th field end if the record is stored in the 2-byte
offsets form. If the field is SQL null, the flag is ORed in the returned
value.
@return	offset of the start of the PREVIOUS field, SQL null flag ORed */
UNIV_INLINE
ulint
rec_2_get_prev_field_end_info(
/*==========================*/
	const rec_t*	rec,	/*!< in: record */
	ulint		n)	/*!< in: field index */
{
	ut_ad(!rec_get_1byte_offs_flag(rec));
	ut_ad(n <= rec_get_n_fields_old(rec));

	return(mach_read_from_2(rec - (REC_N_OLD_EXTRA_BYTES + 2 * n)));
}

/******************************************************//**
Sets the field end info for the nth field if the record is stored in the
1-byte format. */
UNIV_INLINE
void
rec_1_set_field_end_info(
/*=====================*/
	rec_t*	rec,	/*!< in: record */
	ulint	n,	/*!< in: field index */
	ulint	info)	/*!< in: value to set */
{
	ut_ad(rec_get_1byte_offs_flag(rec));
	ut_ad(n < rec_get_n_fields_old(rec));

	mach_write_to_1(rec - (REC_N_OLD_EXTRA_BYTES + n + 1), info);
}

/******************************************************//**
Sets the field end info for the nth field if the record is stored in the
2-byte format. */
UNIV_INLINE
void
rec_2_set_field_end_info(
/*=====================*/
	rec_t*	rec,	/*!< in: record */
	ulint	n,	/*!< in: field index */
	ulint	info)	/*!< in: value to set */
{
	ut_ad(!rec_get_1byte_offs_flag(rec));
	ut_ad(n < rec_get_n_fields_old(rec));

	mach_write_to_2(rec - (REC_N_OLD_EXTRA_BYTES + 2 * n + 2), info);
}

/******************************************************//**
Returns the offset of nth field start if the record is stored in the 1-byte
offsets form.
@return	offset of the start of the field */
UNIV_INLINE
ulint
rec_1_get_field_start_offs(
/*=======================*/
	const rec_t*	rec,	/*!< in: record */
	ulint		n)	/*!< in: field index */
{
	ut_ad(rec_get_1byte_offs_flag(rec));
	ut_ad(n <= rec_get_n_fields_old(rec));

	if (n == 0) {

		return(0);
	}

	return(rec_1_get_prev_field_end_info(rec, n)
	       & ~REC_1BYTE_SQL_NULL_MASK);
}

/******************************************************//**
Returns the offset of nth field start if the record is stored in the 2-byte
offsets form.
@return	offset of the start of the field */
UNIV_INLINE
ulint
rec_2_get_field_start_offs(
/*=======================*/
	const rec_t*	rec,	/*!< in: record */
	ulint		n)	/*!< in: field index */
{
	ut_ad(!rec_get_1byte_offs_flag(rec));
	ut_ad(n <= rec_get_n_fields_old(rec));

	if (n == 0) {

		return(0);
	}

	return(rec_2_get_prev_field_end_info(rec, n)
	       & ~(REC_2BYTE_SQL_NULL_MASK | REC_2BYTE_EXTERN_MASK));
}

/******************************************************//**
The following function is used to read the offset of the start of a data field
in the record. The start of an SQL null field is the end offset of the
previous non-null field, or 0, if none exists. If n is the number of the last
field + 1, then the end offset of the last field is returned.
@return	offset of the start of the field */
UNIV_INLINE
ulint
rec_get_field_start_offs(
/*=====================*/
	const rec_t*	rec,	/*!< in: record */
	ulint		n)	/*!< in: field index */
{
	ut_ad(rec);
	ut_ad(n <= rec_get_n_fields_old(rec));

	if (n == 0) {

		return(0);
	}

	if (rec_get_1byte_offs_flag(rec)) {

		return(rec_1_get_field_start_offs(rec, n));
	}

	return(rec_2_get_field_start_offs(rec, n));
}

/************************************************************//**
Gets the physical size of an old-style field.
Also an SQL null may have a field of size > 0,
if the data type is of a fixed size.
@return	field size in bytes */
UNIV_INLINE
ulint
rec_get_nth_field_size(
/*===================*/
	const rec_t*	rec,	/*!< in: record */
	ulint		n)	/*!< in: index of the field */
{
	ulint	os;
	ulint	next_os;

	os = rec_get_field_start_offs(rec, n);
	next_os = rec_get_field_start_offs(rec, n + 1);

	ut_ad(next_os - os < UNIV_PAGE_SIZE);

	return(next_os - os);
}

/***********************************************************//**
This is used to modify the value of an already existing field in a record.
The previous value must have exactly the same size as the new value. If len
is UNIV_SQL_NULL then the field is treated as an SQL null.
For records in ROW_FORMAT=COMPACT (new-style records), len must not be
UNIV_SQL_NULL unless the field already is SQL null. */
UNIV_INLINE
void
rec_set_nth_field(
/*==============*/
	rec_t*		rec,	/*!< in: record */
	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
	ulint		n,	/*!< in: index number of the field */
	const void*	data,	/*!< in: pointer to the data
				if not SQL null */
	ulint		len)	/*!< in: length of the data or UNIV_SQL_NULL */
{
	byte*	data2;
	ulint	len2;

	ut_ad(rec);
	ut_ad(rec_offs_validate(rec, NULL, offsets));

	if (len == UNIV_SQL_NULL) {
		if (!rec_offs_nth_sql_null(offsets, n)) {
			ut_a(!rec_offs_comp(offsets));
			rec_set_nth_field_sql_null(rec, n);
		}

		return;
	}

	data2 = rec_get_nth_field(rec, offsets, n, &len2);
	if (len2 == UNIV_SQL_NULL) {
		ut_ad(!rec_offs_comp(offsets));
		rec_set_nth_field_null_bit(rec, n, FALSE);
		ut_ad(len == rec_get_nth_field_size(rec, n));
	} else {
		ut_ad(len2 == len);
	}

	ut_memcpy(data2, data, len);
}

/**********************************************************//**
The following function returns the data size of an old-style physical
record, that is the sum of field lengths. SQL null fields
are counted as length 0 fields. The value returned by the function
is the distance from record origin to record end in bytes.
@return	size */
UNIV_INLINE
ulint
rec_get_data_size_old(
/*==================*/
	const rec_t*	rec)	/*!< in: physical record */
{
	ut_ad(rec);

	return(rec_get_field_start_offs(rec, rec_get_n_fields_old(rec)));
}

/**********************************************************//**
The following function sets the number of fields in offsets. */
UNIV_INLINE
void
rec_offs_set_n_fields(
/*==================*/
	ulint*	offsets,	/*!< in/out: array returned by
				rec_get_offsets() */
	ulint	n_fields)	/*!< in: number of fields */
{
	ut_ad(offsets);
	ut_ad(n_fields > 0);
	ut_ad(n_fields <= REC_MAX_N_FIELDS);
	ut_ad(n_fields + REC_OFFS_HEADER_SIZE
	      <= rec_offs_get_n_alloc(offsets));
	offsets[1] = n_fields;
}

/**********************************************************//**
The following function returns the data size of a physical
record, that is the sum of field lengths. SQL null fields
are counted as length 0 fields. The value returned by the function
is the distance from record origin to record end in bytes.
@return	size */
UNIV_INLINE
ulint
rec_offs_data_size(
/*===============*/
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	ulint	size;

	ut_ad(rec_offs_validate(NULL, NULL, offsets));
	size = rec_offs_base(offsets)[rec_offs_n_fields(offsets)]
		& REC_OFFS_MASK;
	ut_ad(size < UNIV_PAGE_SIZE);
	return(size);
}

/**********************************************************//**
Returns the total size of record minus data size of record. The value
returned by the function is the distance from record start to record origin
in bytes.
@return	size */
UNIV_INLINE
ulint
rec_offs_extra_size(
/*================*/
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	ulint	size;
	ut_ad(rec_offs_validate(NULL, NULL, offsets));
	size = *rec_offs_base(offsets) & ~(REC_OFFS_COMPACT | REC_OFFS_EXTERNAL);
	ut_ad(size < UNIV_PAGE_SIZE);
	return(size);
}

/**********************************************************//**
Returns the total size of a physical record.
@return	size */
UNIV_INLINE
ulint
rec_offs_size(
/*==========*/
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	return(rec_offs_data_size(offsets) + rec_offs_extra_size(offsets));
}

#ifdef UNIV_DEBUG
/**********************************************************//**
Returns a pointer to the end of the record.
@return	pointer to end */
UNIV_INLINE
byte*
rec_get_end(
/*========*/
	const rec_t*	rec,	/*!< in: pointer to record */
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	ut_ad(rec_offs_validate(rec, NULL, offsets));
	return(const_cast<rec_t*>(rec + rec_offs_data_size(offsets)));
}

/**********************************************************//**
Returns a pointer to the start of the record.
@return	pointer to start */
UNIV_INLINE
byte*
rec_get_start(
/*==========*/
	const rec_t*	rec,	/*!< in: pointer to record */
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	ut_ad(rec_offs_validate(rec, NULL, offsets));
	return(const_cast<rec_t*>(rec - rec_offs_extra_size(offsets)));
}
#endif /* UNIV_DEBUG */

/***************************************************************//**
Copies a physical record to a buffer.
@return	pointer to the origin of the copy */
UNIV_INLINE
rec_t*
rec_copy(
/*=====*/
	void*		buf,	/*!< in: buffer */
	const rec_t*	rec,	/*!< in: physical record */
	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	ulint	extra_len;
	ulint	data_len;

	ut_ad(rec != NULL);
	ut_ad(buf != NULL);
	ut_ad(rec_offs_validate(rec, NULL, offsets));
	ut_ad(rec_validate(rec, offsets));

	extra_len = rec_offs_extra_size(offsets);
	data_len = rec_offs_data_size(offsets);

	ut_memcpy(buf, rec - extra_len, extra_len + data_len);

	return((byte*) buf + extra_len);
}

/**********************************************************//**
Returns the extra size of an old-style physical record if we know its
data size and number of fields.
@return	extra size */
UNIV_INLINE
ulint
rec_get_converted_extra_size(
/*=========================*/
	ulint	data_size,	/*!< in: data size */
	ulint	n_fields,	/*!< in: number of fields */
	ulint	n_ext)		/*!< in: number of externally stored columns */
{
	if (!n_ext && data_size <= REC_1BYTE_OFFS_LIMIT) {

		return(REC_N_OLD_EXTRA_BYTES + n_fields);
	}

	return(REC_N_OLD_EXTRA_BYTES + 2 * n_fields);
}

/**********************************************************//**
The following function returns the size of a data tuple when converted to
a physical record.
@return	size */
UNIV_INLINE
ulint
rec_get_converted_size(
/*===================*/
	dict_index_t*	index,	/*!< in: record descriptor */
	const dtuple_t*	dtuple,	/*!< in: data tuple */
	ulint		n_ext)	/*!< in: number of externally stored columns */
{
	ulint	data_size;
	ulint	extra_size;

	ut_ad(index);
	ut_ad(dtuple);
	ut_ad(dtuple_check_typed(dtuple));

	ut_ad(dict_index_is_univ(index)
	      || dtuple_get_n_fields(dtuple)
	      == (((dtuple_get_info_bits(dtuple) & REC_NEW_STATUS_MASK)
		   == REC_STATUS_NODE_PTR)
		  ? dict_index_get_n_unique_in_tree(index) + 1
		  : dict_index_get_n_fields(index)));

	if (dict_table_is_comp(index->table)) {
		return(rec_get_converted_size_comp(index,
						   dtuple_get_info_bits(dtuple)
						   & REC_NEW_STATUS_MASK,
						   dtuple->fields,
						   dtuple->n_fields, NULL));
	}

	data_size = dtuple_get_data_size(dtuple, 0);

	extra_size = rec_get_converted_extra_size(
		data_size, dtuple_get_n_fields(dtuple), n_ext);

#if 0
	/* This code is inactive since it may be the wrong place to add
	in the size of node pointers used in parent pages AND it is not
	currently needed since ha_innobase::max_supported_key_length()
	ensures that the key size limit for each page size is well below
	the actual limit ((free space on page / 4) - record overhead).
	But those limits will need to be raised when InnoDB can
	support multiple page sizes.  At that time, we will need
	to consider the node pointer on these universal btrees. */

	if (dict_index_is_univ(index)) {
		/* This is for the insert buffer B-tree.
		All fields in the leaf tuple ascend to the
		parent node plus the child page pointer. */

		/* ibuf cannot contain externally stored fields */
		ut_ad(n_ext == 0);

		/* Add the data pointer and recompute extra_size
		based on one more field. */
		data_size += REC_NODE_PTR_SIZE;
		extra_size = rec_get_converted_extra_size(
			data_size,
			dtuple_get_n_fields(dtuple) + 1,
			0);

		/* Be sure dtuple->n_fields has this node ptr
		accounted for.  This function should correspond to
		what rec_convert_dtuple_to_rec() needs in storage.
		In optimistic insert or update-not-in-place, we will
		have to ensure that if the record is converted to a
		node pointer, it will not become too large.*/
	}
#endif

	return(data_size + extra_size);
}

#ifndef UNIV_HOTBACKUP
/************************************************************//**
Folds a prefix of a physical record to a ulint. Folds only existing fields,
that is, checks that we do not run out of the record.
@return	the folded value */
UNIV_INLINE
ulint
rec_fold(
/*=====*/
	const rec_t*	rec,		/*!< in: the physical record */
	const ulint*	offsets,	/*!< in: array returned by
					rec_get_offsets() */
	ulint		n_fields,	/*!< in: number of complete
					fields to fold */
	ulint		n_bytes,	/*!< in: number of bytes to fold
					in an incomplete last field */
	index_id_t	tree_id)	/*!< in: index tree id */
{
	ulint		i;
	const byte*	data;
	ulint		len;
	ulint		fold;
	ulint		n_fields_rec;

	ut_ad(rec_offs_validate(rec, NULL, offsets));
	ut_ad(rec_validate(rec, offsets));
	ut_ad(n_fields + n_bytes > 0);

	n_fields_rec = rec_offs_n_fields(offsets);
	ut_ad(n_fields <= n_fields_rec);
	ut_ad(n_fields < n_fields_rec || n_bytes == 0);

	if (n_fields > n_fields_rec) {
		n_fields = n_fields_rec;
	}

	if (n_fields == n_fields_rec) {
		n_bytes = 0;
	}

	fold = ut_fold_ull(tree_id);

	for (i = 0; i < n_fields; i++) {
		data = rec_get_nth_field(rec, offsets, i, &len);

		if (len != UNIV_SQL_NULL) {
			fold = ut_fold_ulint_pair(fold,
						  ut_fold_binary(data, len));
		}
	}

	if (n_bytes > 0) {
		data = rec_get_nth_field(rec, offsets, i, &len);

		if (len != UNIV_SQL_NULL) {
			if (len > n_bytes) {
				len = n_bytes;
			}

			fold = ut_fold_ulint_pair(fold,
						  ut_fold_binary(data, len));
		}
	}

	return(fold);
}
#endif /* !UNIV_HOTBACKUP */