~drizzle-trunk/drizzle/development

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

The B-tree

(c) 1994-1996 Innobase Oy

Created 6/2/1994 Heikki Tuuri

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

#include "mach0data.h"

#include "mtr0mtr.h"

#include "mtr0log.h"

#define BTR_MAX_NODE_LEVEL	50	/* used in debug checking */

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

Gets a buffer page and declares its latching order level. */

UNIV_INLINE

page_t*

btr_page_get(

/*=========*/

	ulint	space,		/* in: space id */

	ulint	page_no,	/* in: page number */

	ulint	mode,		/* in: latch mode */

	mtr_t*	mtr)		/* in: mtr */

{

	page_t*	page;

	page = buf_page_get(space, page_no, mode, mtr);

#ifdef UNIV_SYNC_DEBUG

	if (mode != RW_NO_LATCH) {

		buf_page_dbg_add_level(page, SYNC_TREE_NODE);

	}

#endif

	return(page);

}

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

Sets the index id field of a page. */

UNIV_INLINE

void

btr_page_set_index_id(

/*==================*/

	page_t*		page,	/* in: page to be created */

	dulint		id,	/* in: index id */

	mtr_t*		mtr)	/* in: mtr */

{

	mlog_write_dulint(page + PAGE_HEADER + PAGE_INDEX_ID, id, mtr);

}

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

Gets the index id field of a page. */

UNIV_INLINE

dulint

btr_page_get_index_id(

/*==================*/

				/* out: index id */

	page_t*		page)	/* in: index page */

{

	return(mach_read_from_8(page + PAGE_HEADER + PAGE_INDEX_ID));

}

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

Gets the node level field in an index page. */

UNIV_INLINE

ulint

btr_page_get_level_low(

/*===================*/

			/* out: level, leaf level == 0 */

	page_t*	page)	/* in: index page */

{

	ulint	level;

	ut_ad(page);

	level = mach_read_from_2(page + PAGE_HEADER + PAGE_LEVEL);

	ut_ad(level <= BTR_MAX_NODE_LEVEL);

	return(level);

}

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

Gets the node level field in an index page. */

UNIV_INLINE

ulint

btr_page_get_level(

/*===============*/

			/* out: level, leaf level == 0 */

	page_t*	page,	/* in: index page */

	mtr_t*	mtr __attribute__((unused))) /* in: mini-transaction handle */

{

	ut_ad(page && mtr);

	return(btr_page_get_level_low(page));

}

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

Sets the node level field in an index page. */

UNIV_INLINE

void

btr_page_set_level(

/*===============*/

	page_t*	page,	/* in: index page */

	ulint	level,	/* in: level, leaf level == 0 */

	mtr_t*	mtr)	/* in: mini-transaction handle */

{

	ut_ad(page && mtr);

	ut_ad(level <= BTR_MAX_NODE_LEVEL);

	mlog_write_ulint(page + PAGE_HEADER + PAGE_LEVEL, level,

			 MLOG_2BYTES, mtr);

}

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

Gets the next index page number. */

UNIV_INLINE

ulint

btr_page_get_next(

/*==============*/

			/* out: next page number */

	page_t*	page,	/* in: index page */

	mtr_t*	mtr __attribute__((unused))) /* in: mini-transaction handle */

{

	ut_ad(page && mtr);

	ut_ad(mtr_memo_contains(mtr, buf_block_align(page),

				MTR_MEMO_PAGE_X_FIX)

	      || mtr_memo_contains(mtr, buf_block_align(page),

				   MTR_MEMO_PAGE_S_FIX));

	return(mach_read_from_4(page + FIL_PAGE_NEXT));

}

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

Sets the next index page field. */

UNIV_INLINE

void

btr_page_set_next(

/*==============*/

	page_t*	page,	/* in: index page */

	ulint	next,	/* in: next page number */

	mtr_t*	mtr)	/* in: mini-transaction handle */

{

	ut_ad(page && mtr);

	mlog_write_ulint(page + FIL_PAGE_NEXT, next, MLOG_4BYTES, mtr);

}

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

Gets the previous index page number. */

UNIV_INLINE

ulint

btr_page_get_prev(

/*==============*/

			/* out: prev page number */

	page_t*	page,	/* in: index page */

	mtr_t*	mtr __attribute__((unused))) /* in: mini-transaction handle */

{

	ut_ad(page && mtr);

	return(mach_read_from_4(page + FIL_PAGE_PREV));

}

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

Sets the previous index page field. */

UNIV_INLINE

void

btr_page_set_prev(

/*==============*/

	page_t*	page,	/* in: index page */

	ulint	prev,	/* in: previous page number */

	mtr_t*	mtr)	/* in: mini-transaction handle */

{

	ut_ad(page && mtr);

	mlog_write_ulint(page + FIL_PAGE_PREV, prev, MLOG_4BYTES, mtr);

}

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

Gets the child node file address in a node pointer. */

UNIV_INLINE

ulint

btr_node_ptr_get_child_page_no(

/*===========================*/

				/* out: child node address */

	rec_t*		rec,	/* in: node pointer record */

	const ulint*	offsets)/* in: array returned by rec_get_offsets() */

{

	byte*	field;

	ulint	len;

	ulint	page_no;

	ut_ad(!rec_offs_comp(offsets) || rec_get_node_ptr_flag(rec));

	/* The child address is in the last field */

	field = rec_get_nth_field(rec, offsets,

				  rec_offs_n_fields(offsets) - 1, &len);

	ut_ad(len == 4);

	page_no = mach_read_from_4(field);

	if (UNIV_UNLIKELY(page_no == 0)) {

		fprintf(stderr,

			"InnoDB: a nonsensical page number 0"

			" in a node ptr record at offset %lu\n",

			(ulong) page_offset(rec));

		buf_page_print(buf_frame_align(rec));

	}

	return(page_no);

}

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

Releases the latches on a leaf page and bufferunfixes it. */

UNIV_INLINE

void

btr_leaf_page_release(

/*==================*/

	page_t*	page,		/* in: page */

	ulint	latch_mode,	/* in: BTR_SEARCH_LEAF or BTR_MODIFY_LEAF */

	mtr_t*	mtr)		/* in: mtr */

{

	ut_ad(!mtr_memo_contains(mtr, buf_block_align(page),

				 MTR_MEMO_MODIFY));

	if (latch_mode == BTR_SEARCH_LEAF) {

		mtr_memo_release(mtr, buf_block_align(page),

				 MTR_MEMO_PAGE_S_FIX);

	} else {

		ut_ad(latch_mode == BTR_MODIFY_LEAF);

		mtr_memo_release(mtr, buf_block_align(page),

				 MTR_MEMO_PAGE_X_FIX);

	}

}