/******************************************************The B-tree(c) 1994-1996 Innobase OyCreated 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_INLINEpage_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_INLINEvoidbtr_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_INLINEdulintbtr_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_INLINEulintbtr_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_INLINEulintbtr_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_INLINEvoidbtr_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_INLINEulintbtr_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_INLINEvoidbtr_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_INLINEulintbtr_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_INLINEvoidbtr_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_INLINEulintbtr_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) ut_align_offset(rec, UNIV_PAGE_SIZE));		buf_page_print(buf_frame_align(rec));	}	return(page_no);}/******************************************************************Releases the latches on a leaf page and bufferunfixes it. */UNIV_INLINEvoidbtr_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);	}}