btr0cur.c

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

				/* Release the tree s-latch */

				mtr_release_s_latch_at_savepoint(
						mtr, savepoint,
						dict_tree_get_lock(tree));
			}

			page_mode = mode;
		}

		page_cur_search_with_match(page, index, tuple, page_mode,
					&up_match, &up_bytes,
					&low_match, &low_bytes, page_cursor);
		if (estimate) {
			btr_cur_add_path_info(cursor, height, root_height);
		}	

		/* If this is the desired level, leave the loop */

		ut_ad(height
		== btr_page_get_level(page_cur_get_page(page_cursor), mtr));

		if (level == height) {

			if (level > 0) {
				/* x-latch the page */
				page = btr_page_get(space,
						page_no, RW_X_LATCH, mtr);
				ut_a((ibool)!!page_is_comp(page)
						== index->table->comp);
			}

			break;
		}

		ut_ad(height > 0);

		height--;
		guess = NULL;

		node_ptr = page_cur_get_rec(page_cursor);
		offsets = rec_get_offsets(node_ptr, cursor->index, offsets,
						ULINT_UNDEFINED, &heap);
		/* Go to the child node */
		page_no = btr_node_ptr_get_child_page_no(node_ptr, offsets);
	}

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}

	if (level == 0) {
		cursor->low_match = low_match;
		cursor->low_bytes = low_bytes;
		cursor->up_match = up_match;
		cursor->up_bytes = up_bytes;

#ifdef BTR_CUR_ADAPT		
		if (srv_use_adaptive_hash_indexes) {

			btr_search_info_update(index, cursor);
		}
#endif
		ut_ad(cursor->up_match != ULINT_UNDEFINED
						|| mode != PAGE_CUR_GE);
		ut_ad(cursor->up_match != ULINT_UNDEFINED
						|| mode != PAGE_CUR_LE);
		ut_ad(cursor->low_match != ULINT_UNDEFINED
						|| mode != PAGE_CUR_LE);
	}

	if (has_search_latch) {
		
		rw_lock_s_lock(&btr_search_latch);
	}
}

/*********************************************************************
Opens a cursor at either end of an index. */

void
btr_cur_open_at_index_side(
/*=======================*/
	ibool		from_left,	/* in: TRUE if open to the low end,
					FALSE if to the high end */
	dict_index_t*	index,		/* in: index */
	ulint		latch_mode,	/* in: latch mode */
	btr_cur_t*	cursor,		/* in: cursor */
	mtr_t*		mtr)		/* in: mtr */
{
	page_cur_t*	page_cursor;
	dict_tree_t*	tree;
	page_t*		page;
	ulint		page_no;
	ulint		space;
	ulint		height;
	ulint		root_height = 0; /* remove warning */
	rec_t*		node_ptr;
	ulint		estimate;
	ulint           savepoint;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	estimate = latch_mode & BTR_ESTIMATE;
	latch_mode = latch_mode & ~BTR_ESTIMATE;
	
	tree = index->tree;
	
	/* Store the position of the tree latch we push to mtr so that we
	know how to release it when we have latched the leaf node */

	savepoint = mtr_set_savepoint(mtr);

	if (latch_mode == BTR_MODIFY_TREE) {
		mtr_x_lock(dict_tree_get_lock(tree), mtr);
	} else {
		mtr_s_lock(dict_tree_get_lock(tree), mtr);
	}
	
	page_cursor = btr_cur_get_page_cur(cursor);
	cursor->index = index;

	space = dict_tree_get_space(tree);
	page_no = dict_tree_get_page(tree);

	height = ULINT_UNDEFINED;

	for (;;) {
		page = buf_page_get_gen(space, page_no, RW_NO_LATCH, NULL,
					BUF_GET,
					__FILE__, __LINE__,
					mtr);
		ut_ad(0 == ut_dulint_cmp(tree->id,
						btr_page_get_index_id(page)));

		buf_block_align(page)->check_index_page_at_flush = TRUE;

		if (height == ULINT_UNDEFINED) {
			/* We are in the root node */

			height = btr_page_get_level(page, mtr);
			root_height = height;
		}

		if (height == 0) {
			btr_cur_latch_leaves(page, space, page_no,
						latch_mode, cursor, mtr);

			/* In versions <= 3.23.52 we had forgotten to
			release the tree latch here. If in an index scan
			we had to scan far to find a record visible to the
			current transaction, that could starve others
			waiting for the tree latch. */
 
			if ((latch_mode != BTR_MODIFY_TREE)
			    && (latch_mode != BTR_CONT_MODIFY_TREE)) {

				/* Release the tree s-latch */

				mtr_release_s_latch_at_savepoint(
						mtr, savepoint,
						dict_tree_get_lock(tree));
			}
		}
		
		if (from_left) {
			page_cur_set_before_first(page, page_cursor);
		} else {
			page_cur_set_after_last(page, page_cursor);
		}

		if (height == 0) {
		        if (estimate) {
			        btr_cur_add_path_info(cursor, height,
						      root_height);
		        }

			break;
		}

		ut_ad(height > 0);

		if (from_left) {
			page_cur_move_to_next(page_cursor);
		} else {
			page_cur_move_to_prev(page_cursor);
		}

		if (estimate) {
			btr_cur_add_path_info(cursor, height, root_height);
		}

		height--;

		node_ptr = page_cur_get_rec(page_cursor);
		offsets = rec_get_offsets(node_ptr, cursor->index, offsets,
						ULINT_UNDEFINED, &heap);
		/* Go to the child node */
		page_no = btr_node_ptr_get_child_page_no(node_ptr, offsets);
	}

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
}
	
/**************************************************************************
Positions a cursor at a randomly chosen position within a B-tree. */

void
btr_cur_open_at_rnd_pos(
/*====================*/
	dict_index_t*	index,		/* in: index */
	ulint		latch_mode,	/* in: BTR_SEARCH_LEAF, ... */
	btr_cur_t*	cursor,		/* in/out: B-tree cursor */
	mtr_t*		mtr)		/* in: mtr */
{
	page_cur_t*	page_cursor;
	dict_tree_t*	tree;
	page_t*		page;
	ulint		page_no;
	ulint		space;
	ulint		height;
	rec_t*		node_ptr;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	tree = index->tree;
	
	if (latch_mode == BTR_MODIFY_TREE) {
		mtr_x_lock(dict_tree_get_lock(tree), mtr);
	} else {
		mtr_s_lock(dict_tree_get_lock(tree), mtr);
	}
	
	page_cursor = btr_cur_get_page_cur(cursor);
	cursor->index = index;

	space = dict_tree_get_space(tree);
	page_no = dict_tree_get_page(tree);

	height = ULINT_UNDEFINED;
	
	for (;;) {
		page = buf_page_get_gen(space, page_no, RW_NO_LATCH, NULL,
					BUF_GET,
					__FILE__, __LINE__,
					mtr);
		ut_ad(0 == ut_dulint_cmp(tree->id,
						btr_page_get_index_id(page)));

		if (height == ULINT_UNDEFINED) {
			/* We are in the root node */

			height = btr_page_get_level(page, mtr);
		}

		if (height == 0) {
			btr_cur_latch_leaves(page, space, page_no,
						latch_mode, cursor, mtr);
		}

		page_cur_open_on_rnd_user_rec(page, page_cursor);	

		if (height == 0) {

			break;
		}

		ut_ad(height > 0);

		height--;

		node_ptr = page_cur_get_rec(page_cursor);
		offsets = rec_get_offsets(node_ptr, cursor->index, offsets,
						ULINT_UNDEFINED, &heap);
		/* Go to the child node */
		page_no = btr_node_ptr_get_child_page_no(node_ptr, offsets);
	}

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
}	

/*==================== B-TREE INSERT =========================*/

/*****************************************************************
Inserts a record if there is enough space, or if enough space can
be freed by reorganizing. Differs from _optimistic_insert because
no heuristics is applied to whether it pays to use CPU time for
reorganizing the page or not. */
static
rec_t*
btr_cur_insert_if_possible(
/*=======================*/
				/* out: pointer to inserted record if succeed,
				else NULL */
	btr_cur_t*	cursor,	/* in: cursor on page after which to insert;
				cursor stays valid */
	dtuple_t*	tuple,	/* in: tuple to insert; the size info need not
				have been stored to tuple */
	ibool*		reorg,	/* out: TRUE if reorganization occurred */
	mtr_t*		mtr)	/* in: mtr */
{
	page_cur_t*	page_cursor;
	page_t*		page;
	rec_t*		rec;

	ut_ad(dtuple_check_typed(tuple));
	
	*reorg = FALSE;

	page = btr_cur_get_page(cursor);

	ut_ad(mtr_memo_contains(mtr, buf_block_align(page),
							MTR_MEMO_PAGE_X_FIX));
	page_cursor = btr_cur_get_page_cur(cursor);
	
	/* Now, try the insert */
	rec = page_cur_tuple_insert(page_cursor, tuple, cursor->index, mtr);

	if (!rec) {
		/* If record did not fit, reorganize */

		btr_page_reorganize(page, cursor->index, mtr);

		*reorg = TRUE;

		page_cur_search(page, cursor->index, tuple,
						PAGE_CUR_LE, page_cursor);

		rec = page_cur_tuple_insert(page_cursor, tuple,
						cursor->index, mtr);
	}

	return(rec);
}

/*****************************************************************
For an insert, checks the locks and does the undo logging if desired. */
UNIV_INLINE
ulint
btr_cur_ins_lock_and_undo(
/*======================*/
				/* out: DB_SUCCESS, DB_WAIT_LOCK,
				DB_FAIL, or error number */
	ulint		flags,	/* in: undo logging and locking flags: if
				not zero, the parameters index and thr
				should be specified */
	btr_cur_t*	cursor,	/* in: cursor on page after which to insert */
	dtuple_t*	entry,	/* in: entry to insert */
	que_thr_t*	thr,	/* in: query thread or NULL */
	ibool*		inherit)/* out: TRUE if the inserted new record maybe
				should inherit LOCK_GAP type locks from the
				successor record */
{
	dict_index_t*	index;
	ulint		err;
	rec_t*		rec;
	dulint		roll_ptr;

	/* Check if we have to wait for a lock: enqueue an explicit lock
	request if yes */

	rec = btr_cur_get_rec(cursor);
	index = cursor->index;
	
	err = lock_rec_insert_check_and_lock(flags, rec, index, thr, inherit);
	
	if (err != DB_SUCCESS) {

		return(err);
	}

	if ((index->type & DICT_CLUSTERED) && !(index->type & DICT_IBUF)) {

		err = trx_undo_report_row_operation(flags, TRX_UNDO_INSERT_OP,
					thr, index, entry, NULL, 0, NULL,
					&roll_ptr);
		if (err != DB_SUCCESS) {

			return(err);
		}

		/* Now we can fill in the roll ptr field in entry */

		if (!(flags & BTR_KEEP_SYS_FLAG)) {

			row_upd_index_entry_sys_field(entry, index,
						DATA_ROLL_PTR, roll_ptr);
		}
	}

	return(DB_SUCCESS);
}

#ifdef UNIV_DEBUG
/*****************************************************************
Report information about a transaction. */
static
void
btr_cur_trx_report(
/*===============*/
	trx_t*			trx,	/* in: transaction */
	const dict_index_t*	index,	/* in: index */
	const char*		op)	/* in: operation */
{
	fprintf(stderr, "Trx with id %lu %lu going to ",
		ut_dulint_get_high(trx->id),
		ut_dulint_get_low(trx->id));
	fputs(op, stderr);
	dict_index_name_print(stderr, trx, index);
	putc('\n', stderr);
}
#endif /* UNIV_DEBUG */

/*****************************************************************
Tries to perform an insert to a page in an index tree, next to cursor.
It is assumed that mtr holds an x-latch on the page. The operation does
not succeed if there is too little space on the page. If there is just
one record on the page, the insert will always succeed; this is to
prevent trying to split a page with just one record. */

ulint
btr_cur_optimistic_insert(
/*======================*/
				/* out: DB_SUCCESS, DB_WAIT_LOCK,
				DB_FAIL, or error number */
	ulint		flags,	/* in: undo logging and locking flags: if not
				zero, the parameters index and thr should be
				specified */
	btr_cur_t*	cursor,	/* in: cursor on page after which to insert;
				cursor stays valid */
	dtuple_t*	entry,	/* in: entry to insert */
	rec_t**		rec,	/* out: pointer to inserted record if
				succeed */
	big_rec_t**	big_rec,/* out: big rec vector whose fields have to
				be stored externally by the caller, or
				NULL */
	que_thr_t*	thr,	/* in: query thread or NULL */
	mtr_t*		mtr)	/* in: mtr */
{
	big_rec_t*	big_rec_vec	= NULL;
	dict_index_t*	index;
	page_cur_t*	page_cursor;
	page_t*		page;
	ulint		max_size;
	rec_t*		dummy_rec;
	ulint		level;
	ibool		reorg;
	ibool		inherit;
	ulint		rec_size;
	ulint		type;
	ulint		err;	

	*big_rec = NULL;

	page = btr_cur_get_page(cursor);
	index = cursor->index;

	if (!dtuple_check_typed_no_assert(entry)) {
		fputs("InnoDB: Error in a tuple to insert into ", stderr);
		dict_index_name_print(stderr, thr_get_trx(thr), index);
	}
#ifdef UNIV_DEBUG
	if (btr_cur_print_record_ops && thr) {
		btr_cur_trx_report(thr_get_trx(thr), index, "insert into ");
		dtuple_print(stderr, entry);
	}
#endif /* UNIV_DEBUG */

	ut_ad(mtr_memo_contains(mtr, buf_block_align(page),
							MTR_MEMO_PAGE_X_FIX));
	max_size = page_get_max_insert_size_after_reorganize(page, 1);
	level = btr_page_get_level(page, mtr);

calculate_sizes_again:
	/* Calculate the record size when entry is converted to a record */
	rec_size = rec_get_converted_size(index, entry);

	if (rec_size >=