Beispiel #1
0
ibool
row_undo_search_clust_to_pcur(
/*==========================*/
				/* out: TRUE if found; NOTE the node->pcur
				must be closed by the caller, regardless of
				the return value */
	undo_node_t*	node)	/* in: row undo node */
{
	dict_index_t*	clust_index;
	ibool		found;
	mtr_t		mtr;
	ibool		ret;
	rec_t*		rec;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	mtr_start(&mtr);

	clust_index = dict_table_get_first_index(node->table);

	found = row_search_on_row_ref(&(node->pcur), BTR_MODIFY_LEAF,
				      node->table, node->ref, &mtr);

	rec = btr_pcur_get_rec(&(node->pcur));

	offsets = rec_get_offsets(rec, clust_index, offsets,
				  ULINT_UNDEFINED, &heap);

	if (!found || 0 != ut_dulint_cmp(node->roll_ptr,
					 row_get_rec_roll_ptr(rec, clust_index,
							      offsets))) {

		/* We must remove the reservation on the undo log record
		BEFORE releasing the latch on the clustered index page: this
		is to make sure that some thread will eventually undo the
		modification corresponding to node->roll_ptr. */

		/* fputs("--------------------undoing a previous version\n",
		stderr); */

		ret = FALSE;
	} else {
		node->row = row_build(ROW_COPY_DATA, clust_index, rec,
				      offsets, node->heap);
		btr_pcur_store_position(&(node->pcur), &mtr);

		ret = TRUE;
	}

	btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
	return(ret);
}
Beispiel #2
0
/*******************************************************************//**
Fills the "lock_data" member of i_s_locks_row_t object.
If memory can not be allocated then FALSE is returned.
@return	FALSE if allocation fails */
static
ibool
fill_lock_data(
/*===========*/
	const char**		lock_data,/*!< out: "lock_data" to fill */
	const lock_t*		lock,	/*!< in: lock used to find the data */
	ulint			heap_no,/*!< in: rec num used to find the data */
	trx_i_s_cache_t*	cache)	/*!< in/out: cache where to store
					volatile data */
{
	mtr_t			mtr;

	const buf_block_t*	block;
	const page_t*		page;
	const rec_t*		rec;

	ut_a(lock_get_type(lock) == LOCK_REC);

	mtr_start(&mtr);

	block = buf_page_try_get(lock_rec_get_space_id(lock),
				 lock_rec_get_page_no(lock),
				 &mtr);

	if (block == NULL) {

		*lock_data = NULL;

		mtr_commit(&mtr);

		return(TRUE);
	}

	page = (const page_t*) buf_block_get_frame(block);

	rec = page_find_rec_with_heap_no(page, heap_no);

	if (page_rec_is_infimum(rec)) {

		*lock_data = ha_storage_put_str_memlim(
			cache->storage, "infimum pseudo-record",
			MAX_ALLOWED_FOR_STORAGE(cache));
	} else if (page_rec_is_supremum(rec)) {

		*lock_data = ha_storage_put_str_memlim(
			cache->storage, "supremum pseudo-record",
			MAX_ALLOWED_FOR_STORAGE(cache));
	} else {

		const dict_index_t*	index;
		ulint			n_fields;
		mem_heap_t*		heap;
		ulint			offsets_onstack[REC_OFFS_NORMAL_SIZE];
		ulint*			offsets;
		char			buf[TRX_I_S_LOCK_DATA_MAX_LEN];
		ulint			buf_used;
		ulint			i;

		rec_offs_init(offsets_onstack);
		offsets = offsets_onstack;

		index = lock_rec_get_index(lock);

		n_fields = dict_index_get_n_unique(index);

		ut_a(n_fields > 0);

		heap = NULL;
		offsets = rec_get_offsets(rec, index, offsets, n_fields,
					  &heap);

		/* format and store the data */

		buf_used = 0;
		for (i = 0; i < n_fields; i++) {

			buf_used += put_nth_field(
				buf + buf_used, sizeof(buf) - buf_used,
				i, index, rec, offsets) - 1;
		}

		*lock_data = (const char*) ha_storage_put_memlim(
			cache->storage, buf, buf_used + 1,
			MAX_ALLOWED_FOR_STORAGE(cache));

		if (UNIV_UNLIKELY(heap != NULL)) {

			/* this means that rec_get_offsets() has created a new
			heap and has stored offsets in it; check that this is
			really the case and free the heap */
			ut_a(offsets != offsets_onstack);
			mem_heap_free(heap);
		}
	}

	mtr_commit(&mtr);

	if (*lock_data == NULL) {

		return(FALSE);
	}

	return(TRUE);
}
Beispiel #3
0
/**************************************************************//**
Restores the stored position of a persistent cursor bufferfixing the page and
obtaining the specified latches. If the cursor position was saved when the
(1) cursor was positioned on a user record: this function restores the position
to the last record LESS OR EQUAL to the stored record;
(2) cursor was positioned on a page infimum record: restores the position to
the last record LESS than the user record which was the successor of the page
infimum;
(3) cursor was positioned on the page supremum: restores to the first record
GREATER than the user record which was the predecessor of the supremum.
(4) cursor was positioned before the first or after the last in an empty tree:
restores to before first or after the last in the tree.
@return TRUE if the cursor position was stored when it was on a user
record and it can be restored on a user record whose ordering fields
are identical to the ones of the original user record */
UNIV_INTERN
ibool
btr_pcur_restore_position_func(
/*===========================*/
	ulint		latch_mode,	/*!< in: BTR_SEARCH_LEAF, ... */
	btr_pcur_t*	cursor,		/*!< in: detached persistent cursor */
	const char*	file,		/*!< in: file name */
	ulint		line,		/*!< in: line where called */
	mtr_t*		mtr)		/*!< in: mtr */
{
	dict_index_t*	index;
	dtuple_t*	tuple;
	ulint		mode;
	ulint		old_mode;
	mem_heap_t*	heap;

	ut_ad(mtr);
	ut_ad(mtr->state == MTR_ACTIVE);

	index = btr_cur_get_index(btr_pcur_get_btr_cur(cursor));

	if (UNIV_UNLIKELY(cursor->old_stored != BTR_PCUR_OLD_STORED)
	    || UNIV_UNLIKELY(cursor->pos_state != BTR_PCUR_WAS_POSITIONED
			     && cursor->pos_state != BTR_PCUR_IS_POSITIONED)) {
		ut_print_buf(stderr, cursor, sizeof(btr_pcur_t));
		putc('\n', stderr);
		if (cursor->trx_if_known) {
			trx_print(stderr, cursor->trx_if_known, 0);
		}

		ut_error;
	}

	if (UNIV_UNLIKELY
	    (cursor->rel_pos == BTR_PCUR_AFTER_LAST_IN_TREE
	     || cursor->rel_pos == BTR_PCUR_BEFORE_FIRST_IN_TREE)) {

		/* In these cases we do not try an optimistic restoration,
		but always do a search */

		btr_cur_open_at_index_side(
			cursor->rel_pos == BTR_PCUR_BEFORE_FIRST_IN_TREE,
			index, latch_mode, btr_pcur_get_btr_cur(cursor), mtr);

		cursor->latch_mode = latch_mode;
		cursor->pos_state = BTR_PCUR_IS_POSITIONED;
		cursor->block_when_stored = btr_pcur_get_block(cursor);

		return(FALSE);
	}

	ut_a(cursor->old_rec);
	ut_a(cursor->old_n_fields);

	if (UNIV_LIKELY(latch_mode == BTR_SEARCH_LEAF)
	    || UNIV_LIKELY(latch_mode == BTR_MODIFY_LEAF)) {
		/* Try optimistic restoration */

		if (UNIV_LIKELY(buf_page_optimistic_get(
					latch_mode,
					cursor->block_when_stored,
					cursor->modify_clock,
					file, line, mtr))) {
			cursor->pos_state = BTR_PCUR_IS_POSITIONED;

			buf_block_dbg_add_level(
				btr_pcur_get_block(cursor),
				dict_index_is_ibuf(index)
				? SYNC_IBUF_TREE_NODE : SYNC_TREE_NODE);

			if (cursor->rel_pos == BTR_PCUR_ON) {
#ifdef UNIV_DEBUG
				const rec_t*	rec;
				const ulint*	offsets1;
				const ulint*	offsets2;
#endif /* UNIV_DEBUG */
				cursor->latch_mode = latch_mode;
#ifdef UNIV_DEBUG
				rec = btr_pcur_get_rec(cursor);

				heap = mem_heap_create(256);
				offsets1 = rec_get_offsets(
					cursor->old_rec, index, NULL,
					cursor->old_n_fields, &heap);
				offsets2 = rec_get_offsets(
					rec, index, NULL,
					cursor->old_n_fields, &heap);

				ut_ad(!cmp_rec_rec(cursor->old_rec,
						   rec, offsets1, offsets2,
						   index));
				mem_heap_free(heap);
#endif /* UNIV_DEBUG */
				return(TRUE);
			}

			return(FALSE);
		}
	}

	/* If optimistic restoration did not succeed, open the cursor anew */

	heap = mem_heap_create(256);

	tuple = dict_index_build_data_tuple(index, cursor->old_rec,
					    cursor->old_n_fields, heap);

	/* Save the old search mode of the cursor */
	old_mode = cursor->search_mode;

	switch (cursor->rel_pos) {
	case BTR_PCUR_ON:
		mode = PAGE_CUR_LE;
		break;
	case BTR_PCUR_AFTER:
		mode = PAGE_CUR_G;
		break;
	case BTR_PCUR_BEFORE:
		mode = PAGE_CUR_L;
		break;
	default:
		ut_error;
		mode = 0;
	}

	btr_pcur_open_with_no_init_func(index, tuple, mode, latch_mode,
					cursor, 0, file, line, mtr);

	/* Restore the old search mode */
	cursor->search_mode = old_mode;

	switch (cursor->rel_pos) {
	case BTR_PCUR_ON:
		if (btr_pcur_is_on_user_rec(cursor)
		    && !cmp_dtuple_rec(
			    tuple, btr_pcur_get_rec(cursor),
			    rec_get_offsets(btr_pcur_get_rec(cursor),
					    index, NULL,
					    ULINT_UNDEFINED, &heap))) {

			/* We have to store the NEW value for
			the modify clock, since the cursor can
			now be on a different page! But we can
			retain the value of old_rec */

			cursor->block_when_stored =
				btr_pcur_get_block(cursor);
			cursor->modify_clock =
				buf_block_get_modify_clock(
					cursor->block_when_stored);
			cursor->old_stored = BTR_PCUR_OLD_STORED;

			mem_heap_free(heap);

			return(TRUE);
		}
#ifdef UNIV_DEBUG
		/* fall through */
	case BTR_PCUR_BEFORE:
	case BTR_PCUR_AFTER:
		break;
	default:
		ut_error;
#endif /* UNIV_DEBUG */
	}

	mem_heap_free(heap);

	/* We have to store new position information, modify_clock etc.,
	to the cursor because it can now be on a different page, the record
	under it may have been removed, etc. */

	btr_pcur_store_position(cursor, mtr);

	return(FALSE);
}
ibool
btr_pcur_restore_position(
/*======================*/
					/* out: TRUE if the cursor position
					was stored when it was on a user record
					and it can be restored on a user record
					whose ordering fields are identical to
					the ones of the original user record */
	ulint		latch_mode,	/* in: BTR_SEARCH_LEAF, ... */
	btr_pcur_t*	cursor,		/* in: detached persistent cursor */
	mtr_t*		mtr)		/* in: mtr */
{
	dict_index_t*	index;
	page_t*		page;
	dtuple_t*	tuple;
	ulint		mode;
	ulint		old_mode;
	mem_heap_t*	heap;

	index = btr_cur_get_index(btr_pcur_get_btr_cur(cursor));

	if (UNIV_UNLIKELY(cursor->old_stored != BTR_PCUR_OLD_STORED)
	    || UNIV_UNLIKELY(cursor->pos_state != BTR_PCUR_WAS_POSITIONED
			     && cursor->pos_state != BTR_PCUR_IS_POSITIONED)) {
		ut_print_buf(stderr, cursor, sizeof(btr_pcur_t));
		if (cursor->trx_if_known) {
			trx_print(stderr, cursor->trx_if_known, 0);
		}

		ut_error;
	}

	if (UNIV_UNLIKELY(
		    cursor->rel_pos == BTR_PCUR_AFTER_LAST_IN_TREE
		    || cursor->rel_pos == BTR_PCUR_BEFORE_FIRST_IN_TREE)) {

		/* In these cases we do not try an optimistic restoration,
		but always do a search */

		btr_cur_open_at_index_side(
			cursor->rel_pos == BTR_PCUR_BEFORE_FIRST_IN_TREE,
			index, latch_mode, btr_pcur_get_btr_cur(cursor), mtr);

		cursor->block_when_stored
			= buf_block_align(btr_pcur_get_page(cursor));

		return(FALSE);
	}

	ut_a(cursor->old_rec);
	ut_a(cursor->old_n_fields);

	page = btr_cur_get_page(btr_pcur_get_btr_cur(cursor));

	if (UNIV_LIKELY(latch_mode == BTR_SEARCH_LEAF)
	    || UNIV_LIKELY(latch_mode == BTR_MODIFY_LEAF)) {
		/* Try optimistic restoration */

		if (UNIV_LIKELY(buf_page_optimistic_get(
					latch_mode,
					cursor->block_when_stored, page,
					cursor->modify_clock, mtr))) {
			cursor->pos_state = BTR_PCUR_IS_POSITIONED;
#ifdef UNIV_SYNC_DEBUG
			buf_page_dbg_add_level(page, SYNC_TREE_NODE);
#endif /* UNIV_SYNC_DEBUG */
			if (cursor->rel_pos == BTR_PCUR_ON) {
#ifdef UNIV_DEBUG
				rec_t*		rec;
				ulint*		offsets1;
				ulint*		offsets2;
#endif /* UNIV_DEBUG */
				cursor->latch_mode = latch_mode;
#ifdef UNIV_DEBUG
				rec = btr_pcur_get_rec(cursor);

				heap = mem_heap_create(256);
				offsets1 = rec_get_offsets(
					cursor->old_rec, index, NULL,
					cursor->old_n_fields, &heap);
				offsets2 = rec_get_offsets(
					rec, index, NULL,
					cursor->old_n_fields, &heap);

				ut_ad(!cmp_rec_rec(cursor->old_rec,
						   rec, offsets1, offsets2,
						   index));
				mem_heap_free(heap);
#endif /* UNIV_DEBUG */
				return(TRUE);
			}

			return(FALSE);
		}
	}

	/* If optimistic restoration did not succeed, open the cursor anew */

	heap = mem_heap_create(256);

	tuple = dict_index_build_data_tuple(index, cursor->old_rec,
					    cursor->old_n_fields, heap);

	/* Save the old search mode of the cursor */
	old_mode = cursor->search_mode;

	switch (cursor->rel_pos) {
	case BTR_PCUR_ON:
		mode = PAGE_CUR_LE;
		break;
	case BTR_PCUR_AFTER:
		mode = PAGE_CUR_G;
		break;
	case BTR_PCUR_BEFORE:
		mode = PAGE_CUR_L;
		break;
	default:
		ut_error;
		mode = 0; /* silence a warning */
	}

	btr_pcur_open_with_no_init(index, tuple, mode, latch_mode,
				   cursor, 0, mtr);

	/* Restore the old search mode */
	cursor->search_mode = old_mode;

	if (btr_pcur_is_on_user_rec(cursor, mtr)) {
		switch (cursor->rel_pos) {
		case BTR_PCUR_ON:
			if (!cmp_dtuple_rec(
				    tuple, btr_pcur_get_rec(cursor),
				    rec_get_offsets(btr_pcur_get_rec(cursor),
						    index, NULL,
						    ULINT_UNDEFINED, &heap))) {

				/* We have to store the NEW value for
				the modify clock, since the cursor can
				now be on a different page! But we can
				retain the value of old_rec */

				cursor->block_when_stored =
					buf_block_align(
						btr_pcur_get_page(cursor));
				cursor->modify_clock =
					buf_block_get_modify_clock(
						cursor->block_when_stored);
				cursor->old_stored = BTR_PCUR_OLD_STORED;

				mem_heap_free(heap);

				return(TRUE);
			}

			break;
		case BTR_PCUR_BEFORE:
			page_cur_move_to_next(btr_pcur_get_page_cur(cursor));
			break;
		case BTR_PCUR_AFTER:
			page_cur_move_to_prev(btr_pcur_get_page_cur(cursor));
			break;
#ifdef UNIV_DEBUG
		default:
			ut_error;
#endif /* UNIV_DEBUG */
		}
	}

	mem_heap_free(heap);

	/* We have to store new position information, modify_clock etc.,
	to the cursor because it can now be on a different page, the record
	under it may have been removed, etc. */

	btr_pcur_store_position(cursor, mtr);

	return(FALSE);
}
Beispiel #5
0
/*******************************************************************//**
Builds from a secondary index record a row reference with which we can
search the clustered index record. */
UNIV_INTERN
void
row_build_row_ref_in_tuple(
/*=======================*/
	dtuple_t*		ref,	/*!< in/out: row reference built;
					see the NOTE below! */
	const rec_t*		rec,	/*!< in: record in the index;
					NOTE: the data fields in ref
					will point directly into this
					record, therefore, the buffer
					page of this record must be at
					least s-latched and the latch
					held as long as the row
					reference is used! */
	const dict_index_t*	index,	/*!< in: secondary index */
	ulint*			offsets,/*!< in: rec_get_offsets(rec, index)
					or NULL */
	trx_t*			trx)	/*!< in: transaction */
{
	const dict_index_t*	clust_index;
	dfield_t*		dfield;
	const byte*		field;
	ulint			len;
	ulint			ref_len;
	ulint			pos;
	ulint			clust_col_prefix_len;
	ulint			i;
	mem_heap_t*		heap		= NULL;
	ulint			offsets_[REC_OFFS_NORMAL_SIZE];
	rec_offs_init(offsets_);

	ut_a(ref);
	ut_a(index);
	ut_a(rec);
	ut_ad(!dict_index_is_clust(index));

	if (UNIV_UNLIKELY(!index->table)) {
		fputs("InnoDB: table ", stderr);
notfound:
		ut_print_name(stderr, trx, TRUE, index->table_name);
		fputs(" for index ", stderr);
		ut_print_name(stderr, trx, FALSE, index->name);
		fputs(" not found\n", stderr);
		ut_error;
	}

	clust_index = dict_table_get_first_index(index->table);

	if (UNIV_UNLIKELY(!clust_index)) {
		fputs("InnoDB: clust index for table ", stderr);
		goto notfound;
	}

	if (!offsets) {
		offsets = rec_get_offsets(rec, index, offsets_,
					  ULINT_UNDEFINED, &heap);
	} else {
		ut_ad(rec_offs_validate(rec, index, offsets));
	}

	/* Secondary indexes must not contain externally stored columns. */
	ut_ad(!rec_offs_any_extern(offsets));
	ref_len = dict_index_get_n_unique(clust_index);

	ut_ad(ref_len == dtuple_get_n_fields(ref));

	dict_index_copy_types(ref, clust_index, ref_len);

	for (i = 0; i < ref_len; i++) {
		dfield = dtuple_get_nth_field(ref, i);

		pos = dict_index_get_nth_field_pos(index, clust_index, i);

		ut_a(pos != ULINT_UNDEFINED);

		field = rec_get_nth_field(rec, offsets, pos, &len);

		dfield_set_data(dfield, field, len);

		/* If the primary key contains a column prefix, then the
		secondary index may contain a longer prefix of the same
		column, or the full column, and we must adjust the length
		accordingly. */

		clust_col_prefix_len = dict_index_get_nth_field(
			clust_index, i)->prefix_len;

		if (clust_col_prefix_len > 0) {
			if (len != UNIV_SQL_NULL) {

				const dtype_t*	dtype
					= dfield_get_type(dfield);

				dfield_set_len(dfield,
					       dtype_get_at_most_n_mbchars(
						       dtype->prtype,
						       dtype->mbminlen,
						       dtype->mbmaxlen,
						       clust_col_prefix_len,
						       len, (char*) field));
			}
		}
	}

	ut_ad(dtuple_check_typed(ref));
	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
}
Beispiel #6
0
/*******************************************************************//**
Builds from a secondary index record a row reference with which we can
search the clustered index record.
@return	own: row reference built; see the NOTE below! */
UNIV_INTERN
dtuple_t*
row_build_row_ref(
/*==============*/
	ulint		type,	/*!< in: ROW_COPY_DATA, or ROW_COPY_POINTERS:
				the former copies also the data fields to
				heap, whereas the latter only places pointers
				to data fields on the index page */
	dict_index_t*	index,	/*!< in: secondary index */
	const rec_t*	rec,	/*!< in: record in the index;
				NOTE: in the case ROW_COPY_POINTERS
				the data fields in the row will point
				directly into this record, therefore,
				the buffer page of this record must be
				at least s-latched and the latch held
				as long as the row reference is used! */
	mem_heap_t*	heap)	/*!< in: memory heap from which the memory
				needed is allocated */
{
	dict_table_t*	table;
	dict_index_t*	clust_index;
	dfield_t*	dfield;
	dtuple_t*	ref;
	const byte*	field;
	ulint		len;
	ulint		ref_len;
	ulint		pos;
	byte*		buf;
	ulint		clust_col_prefix_len;
	ulint		i;
	mem_heap_t*	tmp_heap	= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	rec_offs_init(offsets_);

	ut_ad(index && rec && heap);
	ut_ad(!dict_index_is_clust(index));

	offsets = rec_get_offsets(rec, index, offsets,
				  ULINT_UNDEFINED, &tmp_heap);
	/* Secondary indexes must not contain externally stored columns. */
	ut_ad(!rec_offs_any_extern(offsets));

	if (type == ROW_COPY_DATA) {
		/* Take a copy of rec to heap */

		buf = mem_heap_alloc(heap, rec_offs_size(offsets));

		rec = rec_copy(buf, rec, offsets);
		/* Avoid a debug assertion in rec_offs_validate(). */
		rec_offs_make_valid(rec, index, offsets);
	}

	table = index->table;

	clust_index = dict_table_get_first_index(table);

	ref_len = dict_index_get_n_unique(clust_index);

	ref = dtuple_create(heap, ref_len);

	dict_index_copy_types(ref, clust_index, ref_len);

	for (i = 0; i < ref_len; i++) {
		dfield = dtuple_get_nth_field(ref, i);

		pos = dict_index_get_nth_field_pos(index, clust_index, i);

		ut_a(pos != ULINT_UNDEFINED);

		field = rec_get_nth_field(rec, offsets, pos, &len);

		dfield_set_data(dfield, field, len);

		/* If the primary key contains a column prefix, then the
		secondary index may contain a longer prefix of the same
		column, or the full column, and we must adjust the length
		accordingly. */

		clust_col_prefix_len = dict_index_get_nth_field(
			clust_index, i)->prefix_len;

		if (clust_col_prefix_len > 0) {
			if (len != UNIV_SQL_NULL) {

				const dtype_t*	dtype
					= dfield_get_type(dfield);

				dfield_set_len(dfield,
					       dtype_get_at_most_n_mbchars(
						       dtype->prtype,
						       dtype->mbminlen,
						       dtype->mbmaxlen,
						       clust_col_prefix_len,
						       len, (char*) field));
			}
		}
	}

	ut_ad(dtuple_check_typed(ref));
	if (tmp_heap) {
		mem_heap_free(tmp_heap);
	}

	return(ref);
}
Beispiel #7
0
/*******************************************************************//**
An inverse function to row_build_index_entry. Builds a row from a
record in a clustered index.
@return	own: row built; see the NOTE below! */
UNIV_INTERN
dtuple_t*
row_build(
/*======*/
	ulint			type,	/*!< in: ROW_COPY_POINTERS or
					ROW_COPY_DATA; the latter
					copies also the data fields to
					heap while the first only
					places pointers to data fields
					on the index page, and thus is
					more efficient */
	const dict_index_t*	index,	/*!< in: clustered index */
	const rec_t*		rec,	/*!< in: record in the clustered
					index; NOTE: in the case
					ROW_COPY_POINTERS the data
					fields in the row will point
					directly into this record,
					therefore, the buffer page of
					this record must be at least
					s-latched and the latch held
					as long as the row dtuple is used! */
	const ulint*		offsets,/*!< in: rec_get_offsets(rec,index)
					or NULL, in which case this function
					will invoke rec_get_offsets() */
	const dict_table_t*	col_table,
					/*!< in: table, to check which
					externally stored columns
					occur in the ordering columns
					of an index, or NULL if
					index->table should be
					consulted instead */
	row_ext_t**		ext,	/*!< out, own: cache of
					externally stored column
					prefixes, or NULL */
	mem_heap_t*		heap)	/*!< in: memory heap from which
					the memory needed is allocated */
{
	dtuple_t*		row;
	const dict_table_t*	table;
	ulint			n_fields;
	ulint			n_ext_cols;
	ulint*			ext_cols	= NULL; /* remove warning */
	ulint			len;
	ulint			row_len;
	byte*			buf;
	ulint			i;
	ulint			j;
	mem_heap_t*		tmp_heap	= NULL;
	ulint			offsets_[REC_OFFS_NORMAL_SIZE];
	rec_offs_init(offsets_);

	ut_ad(index && rec && heap);
	ut_ad(dict_index_is_clust(index));
	ut_ad(!mutex_own(&kernel_mutex));

	if (!offsets) {
		offsets = rec_get_offsets(rec, index, offsets_,
					  ULINT_UNDEFINED, &tmp_heap);
	} else {
		ut_ad(rec_offs_validate(rec, index, offsets));
	}

#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
	if (rec_offs_any_null_extern(rec, offsets)) {
		/* This condition can occur during crash recovery
		before trx_rollback_active() has completed execution,
		or when a concurrently executing
		row_ins_index_entry_low() has committed the B-tree
		mini-transaction but has not yet managed to restore
		the cursor position for writing the big_rec. */
		ut_a(trx_undo_roll_ptr_is_insert(
			     row_get_rec_roll_ptr(rec, index, offsets)));
	}
#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */

	if (type != ROW_COPY_POINTERS) {
		/* Take a copy of rec to heap */
		buf = mem_heap_alloc(heap, rec_offs_size(offsets));
		rec = rec_copy(buf, rec, offsets);
		/* Avoid a debug assertion in rec_offs_validate(). */
		rec_offs_make_valid(rec, index, (ulint*) offsets);
	}

	table = index->table;
	row_len = dict_table_get_n_cols(table);

	row = dtuple_create(heap, row_len);

	dict_table_copy_types(row, table);

	dtuple_set_info_bits(row, rec_get_info_bits(
				     rec, dict_table_is_comp(table)));

	n_fields = rec_offs_n_fields(offsets);
	n_ext_cols = rec_offs_n_extern(offsets);
	if (n_ext_cols) {
		ext_cols = mem_heap_alloc(heap, n_ext_cols * sizeof *ext_cols);
	}

	for (i = j = 0; i < n_fields; i++) {
		dict_field_t*		ind_field
			= dict_index_get_nth_field(index, i);
		const dict_col_t*	col
			= dict_field_get_col(ind_field);
		ulint			col_no
			= dict_col_get_no(col);
		dfield_t*		dfield
			= dtuple_get_nth_field(row, col_no);

		if (ind_field->prefix_len == 0) {

			const byte*	field = rec_get_nth_field(
				rec, offsets, i, &len);

			dfield_set_data(dfield, field, len);
		}

		if (rec_offs_nth_extern(offsets, i)) {
			dfield_set_ext(dfield);

			if (UNIV_LIKELY_NULL(col_table)) {
				ut_a(col_no
				     < dict_table_get_n_cols(col_table));
				col = dict_table_get_nth_col(
					col_table, col_no);
			}

			if (col->ord_part) {
				/* We will have to fetch prefixes of
				externally stored columns that are
				referenced by column prefixes. */
				ext_cols[j++] = col_no;
			}
		}
	}

	ut_ad(dtuple_check_typed(row));

	if (!ext) {
		/* REDUNDANT and COMPACT formats store a local
		768-byte prefix of each externally stored
		column. No cache is needed. */
		ut_ad(dict_table_get_format(index->table)
		      < DICT_TF_FORMAT_ZIP);
	} else if (j) {
		*ext = row_ext_create(j, ext_cols, row,
				      dict_table_zip_size(index->table),
				      heap);
	} else {
		*ext = NULL;
	}

	if (tmp_heap) {
		mem_heap_free(tmp_heap);
	}

	return(row);
}
Beispiel #8
0
/*****************************************************************//**
Constructs the last committed version of a clustered index record,
which should be seen by a semi-consistent read.
@return	DB_SUCCESS or DB_MISSING_HISTORY */
UNIV_INTERN
ulint
row_vers_build_for_semi_consistent_read(
/*====================================*/
	const rec_t*	rec,	/*!< in: record in a clustered index; the
				caller must have a latch on the page; this
				latch locks the top of the stack of versions
				of this records */
	mtr_t*		mtr,	/*!< in: mtr holding the latch on rec */
	dict_index_t*	index,	/*!< in: the clustered index */
	ulint**		offsets,/*!< in/out: offsets returned by
				rec_get_offsets(rec, index) */
	mem_heap_t**	offset_heap,/*!< in/out: memory heap from which
				the offsets are allocated */
	mem_heap_t*	in_heap,/*!< in: memory heap from which the memory for
				*old_vers is allocated; memory for possible
				intermediate versions is allocated and freed
				locally within the function */
	const rec_t**	old_vers)/*!< out: rec, old version, or NULL if the
				record does not exist in the view, that is,
				it was freshly inserted afterwards */
{
	const rec_t*	version;
	mem_heap_t*	heap		= NULL;
	byte*		buf;
	ulint		err;
	trx_id_t	rec_trx_id	= ut_dulint_zero;

	ut_ad(dict_index_is_clust(index));
	ut_ad(mtr_memo_contains_page(mtr, rec, MTR_MEMO_PAGE_X_FIX)
	      || mtr_memo_contains_page(mtr, rec, MTR_MEMO_PAGE_S_FIX));
#ifdef UNIV_SYNC_DEBUG
	ut_ad(!rw_lock_own(&(purge_sys->latch), RW_LOCK_SHARED));
#endif /* UNIV_SYNC_DEBUG */

	ut_ad(rec_offs_validate(rec, index, *offsets));

	rw_lock_s_lock(&(purge_sys->latch));
	/* The S-latch on purge_sys prevents the purge view from
	changing.  Thus, if we have an uncommitted transaction at
	this point, then purge cannot remove its undo log even if
	the transaction could commit now. */

	version = rec;

	for (;;) {
		trx_t*		version_trx;
		mem_heap_t*	heap2;
		rec_t*		prev_version;
		trx_id_t	version_trx_id;

		version_trx_id = row_get_rec_trx_id(version, index, *offsets);
		if (rec == version) {
			rec_trx_id = version_trx_id;
		}

		mutex_enter(&kernel_mutex);
		version_trx = trx_get_on_id(version_trx_id);
		if (version_trx
		    && (version_trx->conc_state == TRX_COMMITTED_IN_MEMORY
			|| version_trx->conc_state == TRX_NOT_STARTED)) {

			version_trx = NULL;
		}
		mutex_exit(&kernel_mutex);

		if (!version_trx) {

			/* We found a version that belongs to a
			committed transaction: return it. */

#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
			ut_a(!rec_offs_any_null_extern(version, *offsets));
#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */

			if (rec == version) {
				*old_vers = rec;
				err = DB_SUCCESS;
				break;
			}

			/* We assume that a rolled-back transaction stays in
			TRX_ACTIVE state until all the changes have been
			rolled back and the transaction is removed from
			the global list of transactions. */

			if (!ut_dulint_cmp(rec_trx_id, version_trx_id)) {
				/* The transaction was committed while
				we searched for earlier versions.
				Return the current version as a
				semi-consistent read. */

				version = rec;
				*offsets = rec_get_offsets(version,
							   index, *offsets,
							   ULINT_UNDEFINED,
							   offset_heap);
			}

			buf = mem_heap_alloc(in_heap, rec_offs_size(*offsets));
			*old_vers = rec_copy(buf, version, *offsets);
			rec_offs_make_valid(*old_vers, index, *offsets);
			err = DB_SUCCESS;

			break;
		}

		heap2 = heap;
		heap = mem_heap_create(1024);

		err = trx_undo_prev_version_build(rec, mtr, version, index,
						  *offsets, heap,
						  &prev_version);
		if (heap2) {
			mem_heap_free(heap2); /* free version */
		}

		if (UNIV_UNLIKELY(err != DB_SUCCESS)) {
			break;
		}

		if (prev_version == NULL) {
			/* It was a freshly inserted version */
			*old_vers = NULL;
			err = DB_SUCCESS;

			break;
		}

		version = prev_version;
		*offsets = rec_get_offsets(version, index, *offsets,
					   ULINT_UNDEFINED, offset_heap);
#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
		ut_a(!rec_offs_any_null_extern(version, *offsets));
#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
	}/* for (;;) */

	if (heap) {
		mem_heap_free(heap);
	}
	rw_lock_s_unlock(&(purge_sys->latch));

	return(err);
}
Beispiel #9
0
/*****************************************************************//**
Finds out if an active transaction has inserted or modified a secondary
index record. NOTE: the kernel mutex is temporarily released in this
function!
@return NULL if committed, else the active transaction */
UNIV_INTERN
trx_t*
row_vers_impl_x_locked_off_kernel(
/*==============================*/
	const rec_t*	rec,	/*!< in: record in a secondary index */
	dict_index_t*	index,	/*!< in: the secondary index */
	const ulint*	offsets)/*!< in: rec_get_offsets(rec, index) */
{
	dict_index_t*	clust_index;
	rec_t*		clust_rec;
	ulint*		clust_offsets;
	rec_t*		version;
	trx_id_t	trx_id;
	mem_heap_t*	heap;
	mem_heap_t*	heap2;
	dtuple_t*	row;
	dtuple_t*	entry	= NULL; /* assignment to eliminate compiler
					warning */
	trx_t*		trx;
	ulint		rec_del;
#ifdef UNIV_DEBUG
	ulint		err;
#endif /* UNIV_DEBUG */
	mtr_t		mtr;
	ulint		comp;

	ut_ad(mutex_own(&kernel_mutex));
#ifdef UNIV_SYNC_DEBUG
	ut_ad(!rw_lock_own(&(purge_sys->latch), RW_LOCK_SHARED));
#endif /* UNIV_SYNC_DEBUG */

	mutex_exit(&kernel_mutex);

	mtr_start(&mtr);

	/* Search for the clustered index record: this is a time-consuming
	operation: therefore we release the kernel mutex; also, the release
	is required by the latching order convention. The latch on the
	clustered index locks the top of the stack of versions. We also
	reserve purge_latch to lock the bottom of the version stack. */

	clust_rec = row_get_clust_rec(BTR_SEARCH_LEAF, rec, index,
				      &clust_index, &mtr);
	if (!clust_rec) {
		/* In a rare case it is possible that no clust rec is found
		for a secondary index record: if in row0umod.c
		row_undo_mod_remove_clust_low() we have already removed the
		clust rec, while purge is still cleaning and removing
		secondary index records associated with earlier versions of
		the clustered index record. In that case there cannot be
		any implicit lock on the secondary index record, because
		an active transaction which has modified the secondary index
		record has also modified the clustered index record. And in
		a rollback we always undo the modifications to secondary index
		records before the clustered index record. */

		mutex_enter(&kernel_mutex);
		mtr_commit(&mtr);

		return(NULL);
	}

	heap = mem_heap_create(1024);
	clust_offsets = rec_get_offsets(clust_rec, clust_index, NULL,
					ULINT_UNDEFINED, &heap);
	trx_id = row_get_rec_trx_id(clust_rec, clust_index, clust_offsets);

	mtr_s_lock(&(purge_sys->latch), &mtr);

	mutex_enter(&kernel_mutex);

	trx = NULL;
	if (!trx_is_active(trx_id)) {
		/* The transaction that modified or inserted clust_rec is no
		longer active: no implicit lock on rec */
		goto exit_func;
	}

	if (!lock_check_trx_id_sanity(trx_id, clust_rec, clust_index,
				      clust_offsets, TRUE)) {
		/* Corruption noticed: try to avoid a crash by returning */
		goto exit_func;
	}

	comp = page_rec_is_comp(rec);
	ut_ad(index->table == clust_index->table);
	ut_ad(!!comp == dict_table_is_comp(index->table));
	ut_ad(!comp == !page_rec_is_comp(clust_rec));

	/* We look up if some earlier version, which was modified by the trx_id
	transaction, of the clustered index record would require rec to be in
	a different state (delete marked or unmarked, or have different field
	values, or not existing). If there is such a version, then rec was
	modified by the trx_id transaction, and it has an implicit x-lock on
	rec. Note that if clust_rec itself would require rec to be in a
	different state, then the trx_id transaction has not yet had time to
	modify rec, and does not necessarily have an implicit x-lock on rec. */

	rec_del = rec_get_deleted_flag(rec, comp);
	trx = NULL;

	version = clust_rec;

	for (;;) {
		rec_t*		prev_version;
		ulint		vers_del;
		row_ext_t*	ext;
		trx_id_t	prev_trx_id;

		mutex_exit(&kernel_mutex);

		/* While we retrieve an earlier version of clust_rec, we
		release the kernel mutex, because it may take time to access
		the disk. After the release, we have to check if the trx_id
		transaction is still active. We keep the semaphore in mtr on
		the clust_rec page, so that no other transaction can update
		it and get an implicit x-lock on rec. */

		heap2 = heap;
		heap = mem_heap_create(1024);
#ifdef UNIV_DEBUG
		err =
#endif /* UNIV_DEBUG */
		trx_undo_prev_version_build(clust_rec, &mtr, version,
					    clust_index, clust_offsets,
					    heap, &prev_version);
		mem_heap_free(heap2); /* free version and clust_offsets */

		if (prev_version == NULL) {
			mutex_enter(&kernel_mutex);

			if (!trx_is_active(trx_id)) {
				/* Transaction no longer active: no
				implicit x-lock */

				break;
			}

			/* If the transaction is still active,
			clust_rec must be a fresh insert, because no
			previous version was found. */
			ut_ad(err == DB_SUCCESS);

			/* It was a freshly inserted version: there is an
			implicit x-lock on rec */

			trx = trx_get_on_id(trx_id);

			break;
		}

		clust_offsets = rec_get_offsets(prev_version, clust_index,
						NULL, ULINT_UNDEFINED, &heap);

		vers_del = rec_get_deleted_flag(prev_version, comp);
		prev_trx_id = row_get_rec_trx_id(prev_version, clust_index,
						 clust_offsets);
		/* The stack of versions is locked by mtr.  Thus, it
		is safe to fetch the prefixes for externally stored
		columns. */
		row = row_build(ROW_COPY_POINTERS, clust_index, prev_version,
				clust_offsets, NULL, &ext, heap);
		entry = row_build_index_entry(row, ext, index, heap);
		/* entry may be NULL if a record was inserted in place
		of a deleted record, and the BLOB pointers of the new
		record were not initialized yet.  But in that case,
		prev_version should be NULL. */
		ut_a(entry);

		mutex_enter(&kernel_mutex);

		if (!trx_is_active(trx_id)) {
			/* Transaction no longer active: no implicit x-lock */

			break;
		}

		/* If we get here, we know that the trx_id transaction is
		still active and it has modified prev_version. Let us check
		if prev_version would require rec to be in a different
		state. */

		/* The previous version of clust_rec must be
		accessible, because the transaction is still active
		and clust_rec was not a fresh insert. */
		ut_ad(err == DB_SUCCESS);

		/* We check if entry and rec are identified in the alphabetical
		ordering */
		if (0 == cmp_dtuple_rec(entry, rec, offsets)) {
			/* The delete marks of rec and prev_version should be
			equal for rec to be in the state required by
			prev_version */

			if (rec_del != vers_del) {
				trx = trx_get_on_id(trx_id);

				break;
			}

			/* It is possible that the row was updated so that the
			secondary index record remained the same in
			alphabetical ordering, but the field values changed
			still. For example, 'abc' -> 'ABC'. Check also that. */

			dtuple_set_types_binary(entry,
						dtuple_get_n_fields(entry));
			if (0 != cmp_dtuple_rec(entry, rec, offsets)) {

				trx = trx_get_on_id(trx_id);

				break;
			}
		} else if (!rec_del) {
			/* The delete mark should be set in rec for it to be
			in the state required by prev_version */

			trx = trx_get_on_id(trx_id);

			break;
		}

		if (0 != ut_dulint_cmp(trx_id, prev_trx_id)) {
			/* The versions modified by the trx_id transaction end
			to prev_version: no implicit x-lock */

			break;
		}

		version = prev_version;
	}/* for (;;) */

exit_func:
	mtr_commit(&mtr);
	mem_heap_free(heap);

	return(trx);
}
Beispiel #10
0
/*****************************************************************//**
Constructs the version of a clustered index record which a consistent
read should see. We assume that the trx id stored in rec is such that
the consistent read should not see rec in its present version.
@return	DB_SUCCESS or DB_MISSING_HISTORY */
UNIV_INTERN
ulint
row_vers_build_for_consistent_read(
/*===============================*/
	const rec_t*	rec,	/*!< in: record in a clustered index; the
				caller must have a latch on the page; this
				latch locks the top of the stack of versions
				of this records */
	mtr_t*		mtr,	/*!< in: mtr holding the latch on rec */
	dict_index_t*	index,	/*!< in: the clustered index */
	ulint**		offsets,/*!< in/out: offsets returned by
				rec_get_offsets(rec, index) */
	read_view_t*	view,	/*!< in: the consistent read view */
	mem_heap_t**	offset_heap,/*!< in/out: memory heap from which
				the offsets are allocated */
	mem_heap_t*	in_heap,/*!< in: memory heap from which the memory for
				*old_vers is allocated; memory for possible
				intermediate versions is allocated and freed
				locally within the function */
	rec_t**		old_vers)/*!< out, own: old version, or NULL if the
				record does not exist in the view, that is,
				it was freshly inserted afterwards */
{
	const rec_t*	version;
	rec_t*		prev_version;
	trx_id_t	trx_id;
	mem_heap_t*	heap		= NULL;
	byte*		buf;
	ulint		err;

	ut_ad(dict_index_is_clust(index));
	ut_ad(mtr_memo_contains_page(mtr, rec, MTR_MEMO_PAGE_X_FIX)
	      || mtr_memo_contains_page(mtr, rec, MTR_MEMO_PAGE_S_FIX));
#ifdef UNIV_SYNC_DEBUG
	ut_ad(!rw_lock_own(&(purge_sys->latch), RW_LOCK_SHARED));
#endif /* UNIV_SYNC_DEBUG */

	ut_ad(rec_offs_validate(rec, index, *offsets));

	trx_id = row_get_rec_trx_id(rec, index, *offsets);

	ut_ad(!read_view_sees_trx_id(view, trx_id));

	rw_lock_s_lock(&(purge_sys->latch));
	version = rec;

	for (;;) {
		mem_heap_t*	heap2	= heap;
		trx_undo_rec_t* undo_rec;
		roll_ptr_t	roll_ptr;
		undo_no_t	undo_no;
		heap = mem_heap_create(1024);

		/* If we have high-granularity consistent read view and
		creating transaction of the view is the same as trx_id in
		the record we see this record only in the case when
		undo_no of the record is < undo_no in the view. */

		if (view->type == VIEW_HIGH_GRANULARITY
		    && ut_dulint_cmp(view->creator_trx_id, trx_id) == 0) {

			roll_ptr = row_get_rec_roll_ptr(version, index,
							*offsets);
			undo_rec = trx_undo_get_undo_rec_low(roll_ptr, heap);
			undo_no = trx_undo_rec_get_undo_no(undo_rec);
			mem_heap_empty(heap);

			if (ut_dulint_cmp(view->undo_no, undo_no) > 0) {
				/* The view already sees this version: we can
				copy it to in_heap and return */

#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
				ut_a(!rec_offs_any_null_extern(
					     version, *offsets));
#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */

				buf = mem_heap_alloc(in_heap,
						     rec_offs_size(*offsets));
				*old_vers = rec_copy(buf, version, *offsets);
				rec_offs_make_valid(*old_vers, index,
						    *offsets);
				err = DB_SUCCESS;

				break;
			}
		}

		err = trx_undo_prev_version_build(rec, mtr, version, index,
						  *offsets, heap,
						  &prev_version);
		if (heap2) {
			mem_heap_free(heap2); /* free version */
		}

		if (err != DB_SUCCESS) {
			break;
		}

		if (prev_version == NULL) {
			/* It was a freshly inserted version */
			*old_vers = NULL;
			err = DB_SUCCESS;

			break;
		}

		*offsets = rec_get_offsets(prev_version, index, *offsets,
					   ULINT_UNDEFINED, offset_heap);

#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
		ut_a(!rec_offs_any_null_extern(prev_version, *offsets));
#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */

		trx_id = row_get_rec_trx_id(prev_version, index, *offsets);

		if (read_view_sees_trx_id(view, trx_id)) {

			/* The view already sees this version: we can copy
			it to in_heap and return */

			buf = mem_heap_alloc(in_heap, rec_offs_size(*offsets));
			*old_vers = rec_copy(buf, prev_version, *offsets);
			rec_offs_make_valid(*old_vers, index, *offsets);
			err = DB_SUCCESS;

			break;
		}

		version = prev_version;
	}/* for (;;) */

	mem_heap_free(heap);
	rw_lock_s_unlock(&(purge_sys->latch));

	return(err);
}
Beispiel #11
0
/*****************************************************************//**
Finds out if a version of the record, where the version >= the current
purge view, should have ientry as its secondary index entry. We check
if there is any not delete marked version of the record where the trx
id >= purge view, and the secondary index entry and ientry are identified in
the alphabetical ordering; exactly in this case we return TRUE.
@return	TRUE if earlier version should have */
UNIV_INTERN
ibool
row_vers_old_has_index_entry(
/*=========================*/
	ibool		also_curr,/*!< in: TRUE if also rec is included in the
				versions to search; otherwise only versions
				prior to it are searched */
	const rec_t*	rec,	/*!< in: record in the clustered index; the
				caller must have a latch on the page */
	mtr_t*		mtr,	/*!< in: mtr holding the latch on rec; it will
				also hold the latch on purge_view */
	dict_index_t*	index,	/*!< in: the secondary index */
	const dtuple_t*	ientry)	/*!< in: the secondary index entry */
{
	const rec_t*	version;
	rec_t*		prev_version;
	dict_index_t*	clust_index;
	ulint*		clust_offsets;
	mem_heap_t*	heap;
	mem_heap_t*	heap2;
	const dtuple_t*	row;
	const dtuple_t*	entry;
	ulint		err;
	ulint		comp;

	ut_ad(mtr_memo_contains_page(mtr, rec, MTR_MEMO_PAGE_X_FIX)
	      || mtr_memo_contains_page(mtr, rec, MTR_MEMO_PAGE_S_FIX));
#ifdef UNIV_SYNC_DEBUG
	ut_ad(!rw_lock_own(&(purge_sys->latch), RW_LOCK_SHARED));
#endif /* UNIV_SYNC_DEBUG */
	mtr_s_lock(&(purge_sys->latch), mtr);

	clust_index = dict_table_get_first_index(index->table);

	comp = page_rec_is_comp(rec);
	ut_ad(!dict_table_is_comp(index->table) == !comp);
	heap = mem_heap_create(1024);
	clust_offsets = rec_get_offsets(rec, clust_index, NULL,
					ULINT_UNDEFINED, &heap);

	if (also_curr && !rec_get_deleted_flag(rec, comp)) {
		row_ext_t*	ext;

		/* The stack of versions is locked by mtr.
		Thus, it is safe to fetch the prefixes for
		externally stored columns. */
		row = row_build(ROW_COPY_POINTERS, clust_index,
				rec, clust_offsets, NULL, &ext, heap);
		entry = row_build_index_entry(row, ext, index, heap);

		/* If entry == NULL, the record contains unset BLOB
		pointers.  This must be a freshly inserted record.  If
		this is called from
		row_purge_remove_sec_if_poss_low(), the thread will
		hold latches on the clustered index and the secondary
		index.  Because the insert works in three steps:

			(1) insert the record to clustered index
			(2) store the BLOBs and update BLOB pointers
			(3) insert records to secondary indexes

		the purge thread can safely ignore freshly inserted
		records and delete the secondary index record.  The
		thread that inserted the new record will be inserting
		the secondary index records. */

		/* NOTE that we cannot do the comparison as binary
		fields because the row is maybe being modified so that
		the clustered index record has already been updated to
		a different binary value in a char field, but the
		collation identifies the old and new value anyway! */
		if (entry && !dtuple_coll_cmp(ientry, entry)) {

			mem_heap_free(heap);

			return(TRUE);
		}
	}

	version = rec;

	for (;;) {
		heap2 = heap;
		heap = mem_heap_create(1024);
		err = trx_undo_prev_version_build(rec, mtr, version,
						  clust_index, clust_offsets,
						  heap, &prev_version);
		mem_heap_free(heap2); /* free version and clust_offsets */

		if (err != DB_SUCCESS || !prev_version) {
			/* Versions end here */

			mem_heap_free(heap);

			return(FALSE);
		}

		clust_offsets = rec_get_offsets(prev_version, clust_index,
						NULL, ULINT_UNDEFINED, &heap);

		if (!rec_get_deleted_flag(prev_version, comp)) {
			row_ext_t*	ext;

			/* The stack of versions is locked by mtr.
			Thus, it is safe to fetch the prefixes for
			externally stored columns. */
			row = row_build(ROW_COPY_POINTERS, clust_index,
					prev_version, clust_offsets,
					NULL, &ext, heap);
			entry = row_build_index_entry(row, ext, index, heap);

			/* If entry == NULL, the record contains unset
			BLOB pointers.  This must be a freshly
			inserted record that we can safely ignore.
			For the justification, see the comments after
			the previous row_build_index_entry() call. */

			/* NOTE that we cannot do the comparison as binary
			fields because maybe the secondary index record has
			already been updated to a different binary value in
			a char field, but the collation identifies the old
			and new value anyway! */

			if (entry && !dtuple_coll_cmp(ientry, entry)) {

				mem_heap_free(heap);

				return(TRUE);
			}
		}

		version = prev_version;
	}
}
Beispiel #12
0
/***********************************************************//**
Looks for the clustered index record when node has the row reference.
The pcur in node is used in the search. If found, stores the row to node,
and stores the position of pcur, and detaches it. The pcur must be closed
by the caller in any case.
@return TRUE if found; NOTE the node->pcur must be closed by the
caller, regardless of the return value */
UNIV_INTERN
ibool
row_undo_search_clust_to_pcur(
/*==========================*/
	undo_node_t*	node)	/*!< in: row undo node */
{
	dict_index_t*	clust_index;
	ibool		found;
	mtr_t		mtr;
	ibool		ret;
	rec_t*		rec;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	rec_offs_init(offsets_);

	mtr_start(&mtr);

	clust_index = dict_table_get_first_index(node->table);

	found = row_search_on_row_ref(&(node->pcur), BTR_MODIFY_LEAF,
				      node->table, node->ref, &mtr);

	rec = btr_pcur_get_rec(&(node->pcur));

	offsets = rec_get_offsets(rec, clust_index, offsets,
				  ULINT_UNDEFINED, &heap);

	if (!found || 0 != ut_dulint_cmp(node->roll_ptr,
					 row_get_rec_roll_ptr(rec, clust_index,
							      offsets))) {

		/* We must remove the reservation on the undo log record
		BEFORE releasing the latch on the clustered index page: this
		is to make sure that some thread will eventually undo the
		modification corresponding to node->roll_ptr. */

		/* fputs("--------------------undoing a previous version\n",
		stderr); */

		ret = FALSE;
	} else {
		row_ext_t**	ext;

		if (dict_table_get_format(node->table) >= DICT_TF_FORMAT_ZIP) {
			/* In DYNAMIC or COMPRESSED format, there is
			no prefix of externally stored columns in the
			clustered index record. Build a cache of
			column prefixes. */
			ext = &node->ext;
		} else {
			/* REDUNDANT and COMPACT formats store a local
			768-byte prefix of each externally stored
			column. No cache is needed. */
			ext = NULL;
			node->ext = NULL;
		}

		node->row = row_build(ROW_COPY_DATA, clust_index, rec,
				      offsets, NULL, ext, node->heap);
		if (node->update) {
			node->undo_row = dtuple_copy(node->row, node->heap);
			row_upd_replace(node->undo_row, &node->undo_ext,
					clust_index, node->update, node->heap);
		} else {
			node->undo_row = NULL;
			node->undo_ext = NULL;
		}

		btr_pcur_store_position(&(node->pcur), &mtr);

		ret = TRUE;
	}

	btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
	return(ret);
}
Beispiel #13
0
/***********************************************************//**
Removes a delete marked clustered index record if possible.
@return TRUE if success, or if not found, or if modified after the
delete marking */
static
ibool
row_purge_remove_clust_if_poss_low(
    /*===============================*/
    purge_node_t*	node,	/*!< in: row purge node */
    ulint		mode)	/*!< in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */
{
    dict_index_t*	index;
    btr_pcur_t*	pcur;
    btr_cur_t*	btr_cur;
    ibool		success;
    ulint		err;
    mtr_t		mtr;
    rec_t*		rec;
    mem_heap_t*	heap		= NULL;
    ulint		offsets_[REC_OFFS_NORMAL_SIZE];
    rec_offs_init(offsets_);

    index = dict_table_get_first_index(node->table);

    pcur = &(node->pcur);
    btr_cur = btr_pcur_get_btr_cur(pcur);

    log_free_check();
    mtr_start(&mtr);

    success = row_purge_reposition_pcur(mode, node, &mtr);

    if (!success) {
        /* The record is already removed */

        btr_pcur_commit_specify_mtr(pcur, &mtr);

        return(TRUE);
    }

    rec = btr_pcur_get_rec(pcur);

    if (node->roll_ptr != row_get_rec_roll_ptr(
                rec, index, rec_get_offsets(rec, index, offsets_,
                                            ULINT_UNDEFINED, &heap))) {
        if (UNIV_LIKELY_NULL(heap)) {
            mem_heap_free(heap);
        }
        /* Someone else has modified the record later: do not remove */
        btr_pcur_commit_specify_mtr(pcur, &mtr);

        return(TRUE);
    }

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

    if (mode == BTR_MODIFY_LEAF) {
        success = btr_cur_optimistic_delete(btr_cur, &mtr);
    } else {
        ut_ad(mode == BTR_MODIFY_TREE);
        btr_cur_pessimistic_delete(&err, FALSE, btr_cur,
                                   RB_NONE, &mtr);

        if (err == DB_SUCCESS) {
            success = TRUE;
        } else if (err == DB_OUT_OF_FILE_SPACE) {
            success = FALSE;
        } else {
            ut_error;
        }
    }

    btr_pcur_commit_specify_mtr(pcur, &mtr);

    return(success);
}