示例#1
0
byte*
trx_undo_rec_get_partial_row(
/*=========================*/
				/* out: pointer to remaining part of undo
				record */
	byte*		ptr,	/* in: remaining part in update undo log
				record of a suitable type, at the start of
				the stored index columns;
				NOTE that this copy of the undo log record must
				be preserved as long as the partial row is
				used, as we do NOT copy the data in the
				record! */
	dict_index_t*	index,	/* in: clustered index */
	dtuple_t**	row,	/* out, own: partial row */
	mem_heap_t*	heap)	/* in: memory heap from which the memory
				needed is allocated */
{
	dfield_t*	dfield;
	byte*		field;
	ulint		len;
	ulint		field_no;
	ulint		col_no;
	ulint		row_len;
	ulint		total_len;
	byte*		start_ptr;
	ulint		i;

	ut_ad(index && ptr && row && heap);

	row_len = dict_table_get_n_cols(index->table);

	*row = dtuple_create(heap, row_len);

	dict_table_copy_types(*row, index->table);

	start_ptr = ptr;

	total_len = mach_read_from_2(ptr);
	ptr += 2;

	for (i = 0;; i++) {

		if (ptr == start_ptr + total_len) {

			break;
		}

		ptr = trx_undo_update_rec_get_field_no(ptr, &field_no);

		col_no = dict_index_get_nth_col_no(index, field_no);

		ptr = trx_undo_rec_get_col_val(ptr, &field, &len);

		dfield = dtuple_get_nth_field(*row, col_no);

		dfield_set_data(dfield, field, len);
	}

	return(ptr);
}
示例#2
0
文件: row0row.c 项目: OPSF/uClinux
void
row_build_to_tuple(
/*===============*/
	dtuple_t*	row,	/* in/out: row built; see the NOTE below! */
	dict_index_t*	index,	/* in: clustered index */
	rec_t*		rec)	/* in: record in the clustered index;
				NOTE: 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!
				NOTE 2: does not work with externally
				stored fields! */
{
	dict_table_t*	table;
	ulint		n_fields;
	ulint		i;
	dfield_t*	dfield;
	byte*		field;
	ulint		len;
	ulint		row_len;
	dict_col_t*	col;
	
	ut_ad(index && rec);
	ut_ad(index->type & DICT_CLUSTERED);

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

	dtuple_set_info_bits(row, rec_get_info_bits(rec));
	
	n_fields = dict_index_get_n_fields(index);

	ut_ad(n_fields == rec_get_n_fields(rec));

	dict_table_copy_types(row, table);

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

		col = dict_field_get_col(dict_index_get_nth_field(index, i));
		dfield = dtuple_get_nth_field(row, dict_col_get_no(col));
		field = rec_get_nth_field(rec, i, &len);

		dfield_set_data(dfield, field, len);
	}

	ut_ad(dtuple_check_typed(row));
}
示例#3
0
/**********************************************************************//**
Reports in the undo log of an update or delete marking of a clustered index
record.
@return byte offset of the inserted undo log entry on the page if
succeed, 0 if fail */
static
ulint
trx_undo_page_report_modify(
/*========================*/
	page_t*		undo_page,	/*!< in: undo log page */
	trx_t*		trx,		/*!< in: transaction */
	dict_index_t*	index,		/*!< in: clustered index where update or
					delete marking is done */
	const rec_t*	rec,		/*!< in: clustered index record which
					has NOT yet been modified */
	const ulint*	offsets,	/*!< in: rec_get_offsets(rec, index) */
	const upd_t*	update,		/*!< in: update vector which tells the
					columns to be updated; in the case of
					a delete, this should be set to NULL */
	ulint		cmpl_info,	/*!< in: compiler info on secondary
					index updates */
	mtr_t*		mtr)		/*!< in: mtr */
{
	dict_table_t*	table;
	ulint		first_free;
	byte*		ptr;
	const byte*	field;
	ulint		flen;
	ulint		col_no;
	ulint		type_cmpl;
	byte*		type_cmpl_ptr;
	ulint		i;
	trx_id_t	trx_id;
	ibool		ignore_prefix = FALSE;
	byte		ext_buf[REC_MAX_INDEX_COL_LEN
				+ BTR_EXTERN_FIELD_REF_SIZE];

	ut_a(dict_index_is_clust(index));
	ut_ad(rec_offs_validate(rec, index, offsets));
	ut_ad(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
			       + TRX_UNDO_PAGE_TYPE) == TRX_UNDO_UPDATE);
	table = index->table;

	first_free = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
				      + TRX_UNDO_PAGE_FREE);
	ptr = undo_page + first_free;

	ut_ad(first_free <= UNIV_PAGE_SIZE);

	if (trx_undo_left(undo_page, ptr) < 50) {

		/* NOTE: the value 50 must be big enough so that the general
		fields written below fit on the undo log page */

		return(0);
	}

	/* Reserve 2 bytes for the pointer to the next undo log record */
	ptr += 2;

	/* Store first some general parameters to the undo log */

	if (!update) {
		type_cmpl = TRX_UNDO_DEL_MARK_REC;
	} else if (rec_get_deleted_flag(rec, dict_table_is_comp(table))) {
		type_cmpl = TRX_UNDO_UPD_DEL_REC;
		/* We are about to update a delete marked record.
		We don't typically need the prefix in this case unless
		the delete marking is done by the same transaction
		(which we check below). */
		ignore_prefix = TRUE;
	} else {
		type_cmpl = TRX_UNDO_UPD_EXIST_REC;
	}

	type_cmpl |= cmpl_info * TRX_UNDO_CMPL_INFO_MULT;
	type_cmpl_ptr = ptr;

	*ptr++ = (byte) type_cmpl;
	ptr += mach_dulint_write_much_compressed(ptr, trx->undo_no);

	ptr += mach_dulint_write_much_compressed(ptr, table->id);

	/*----------------------------------------*/
	/* Store the state of the info bits */

	*ptr++ = (byte) rec_get_info_bits(rec, dict_table_is_comp(table));

	/* Store the values of the system columns */
	field = rec_get_nth_field(rec, offsets,
				  dict_index_get_sys_col_pos(
					  index, DATA_TRX_ID), &flen);
	ut_ad(flen == DATA_TRX_ID_LEN);

	trx_id = trx_read_trx_id(field);

	/* If it is an update of a delete marked record, then we are
	allowed to ignore blob prefixes if the delete marking was done
	by some other trx as it must have committed by now for us to
	allow an over-write. */
	if (ignore_prefix) {
		ignore_prefix = ut_dulint_cmp(trx_id, trx->id) != 0;
	}
	ptr += mach_dulint_write_compressed(ptr, trx_id);

	field = rec_get_nth_field(rec, offsets,
				  dict_index_get_sys_col_pos(
					  index, DATA_ROLL_PTR), &flen);
	ut_ad(flen == DATA_ROLL_PTR_LEN);

	ptr += mach_dulint_write_compressed(ptr, trx_read_roll_ptr(field));

	/*----------------------------------------*/
	/* Store then the fields required to uniquely determine the
	record which will be modified in the clustered index */

	for (i = 0; i < dict_index_get_n_unique(index); i++) {

		field = rec_get_nth_field(rec, offsets, i, &flen);

		/* The ordering columns must not be stored externally. */
		ut_ad(!rec_offs_nth_extern(offsets, i));
		ut_ad(dict_index_get_nth_col(index, i)->ord_part);

		if (trx_undo_left(undo_page, ptr) < 5) {

			return(0);
		}

		ptr += mach_write_compressed(ptr, flen);

		if (flen != UNIV_SQL_NULL) {
			if (trx_undo_left(undo_page, ptr) < flen) {

				return(0);
			}

			ut_memcpy(ptr, field, flen);
			ptr += flen;
		}
	}

	/*----------------------------------------*/
	/* Save to the undo log the old values of the columns to be updated. */

	if (update) {
		if (trx_undo_left(undo_page, ptr) < 5) {

			return(0);
		}

		ptr += mach_write_compressed(ptr, upd_get_n_fields(update));

		for (i = 0; i < upd_get_n_fields(update); i++) {

			ulint	pos = upd_get_nth_field(update, i)->field_no;

			/* Write field number to undo log */
			if (trx_undo_left(undo_page, ptr) < 5) {

				return(0);
			}

			ptr += mach_write_compressed(ptr, pos);

			/* Save the old value of field */
			field = rec_get_nth_field(rec, offsets, pos, &flen);

			if (trx_undo_left(undo_page, ptr) < 15) {

				return(0);
			}

			if (rec_offs_nth_extern(offsets, pos)) {
				ptr = trx_undo_page_report_modify_ext(
					ptr,
					dict_index_get_nth_col(index, pos)
					->ord_part
					&& !ignore_prefix
					&& flen < REC_MAX_INDEX_COL_LEN
					? ext_buf : NULL,
					dict_table_zip_size(table),
					&field, &flen);

				/* Notify purge that it eventually has to
				free the old externally stored field */

				trx->update_undo->del_marks = TRUE;

				*type_cmpl_ptr |= TRX_UNDO_UPD_EXTERN;
			} else {
				ptr += mach_write_compressed(ptr, flen);
			}

			if (flen != UNIV_SQL_NULL) {
				if (trx_undo_left(undo_page, ptr) < flen) {

					return(0);
				}

				ut_memcpy(ptr, field, flen);
				ptr += flen;
			}
		}
	}

	/*----------------------------------------*/
	/* In the case of a delete marking, and also in the case of an update
	where any ordering field of any index changes, store the values of all
	columns which occur as ordering fields in any index. This info is used
	in the purge of old versions where we use it to build and search the
	delete marked index records, to look if we can remove them from the
	index tree. Note that starting from 4.0.14 also externally stored
	fields can be ordering in some index. Starting from 5.2, we no longer
	store REC_MAX_INDEX_COL_LEN first bytes to the undo log record,
	but we can construct the column prefix fields in the index by
	fetching the first page of the BLOB that is pointed to by the
	clustered index. This works also in crash recovery, because all pages
	(including BLOBs) are recovered before anything is rolled back. */

	if (!update || !(cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
		byte*	old_ptr = ptr;

		trx->update_undo->del_marks = TRUE;

		if (trx_undo_left(undo_page, ptr) < 5) {

			return(0);
		}

		/* Reserve 2 bytes to write the number of bytes the stored
		fields take in this undo record */

		ptr += 2;

		for (col_no = 0; col_no < dict_table_get_n_cols(table);
		     col_no++) {

			const dict_col_t*	col
				= dict_table_get_nth_col(table, col_no);

			if (col->ord_part) {
				ulint	pos;

				/* Write field number to undo log */
				if (trx_undo_left(undo_page, ptr) < 5 + 15) {

					return(0);
				}

				pos = dict_index_get_nth_col_pos(index,
								 col_no);
				ptr += mach_write_compressed(ptr, pos);

				/* Save the old value of field */
				field = rec_get_nth_field(rec, offsets, pos,
							  &flen);

				if (rec_offs_nth_extern(offsets, pos)) {
					ptr = trx_undo_page_report_modify_ext(
						ptr,
						flen < REC_MAX_INDEX_COL_LEN
						&& !ignore_prefix
						? ext_buf : NULL,
						dict_table_zip_size(table),
						&field, &flen);
				} else {
					ptr += mach_write_compressed(
						ptr, flen);
				}

				if (flen != UNIV_SQL_NULL) {
					if (trx_undo_left(undo_page, ptr)
					    < flen) {

						return(0);
					}

					ut_memcpy(ptr, field, flen);
					ptr += flen;
				}
			}
		}

		mach_write_to_2(old_ptr, ptr - old_ptr);
	}

	/*----------------------------------------*/
	/* Write pointers to the previous and the next undo log records */
	if (trx_undo_left(undo_page, ptr) < 2) {

		return(0);
	}

	mach_write_to_2(ptr, first_free);
	ptr += 2;
	mach_write_to_2(undo_page + first_free, ptr - undo_page);

	mach_write_to_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE,
			ptr - undo_page);

	/* Write to the REDO log about this change in the UNDO log */

	trx_undof_page_add_undo_rec_log(undo_page, first_free,
					ptr - undo_page, mtr);
	return(first_free);
}
示例#4
0
/*******************************************************************//**
Builds a partial row from an update undo log record. It contains the
columns which occur as ordering in any index of the table.
@return	pointer to remaining part of undo record */
UNIV_INTERN
byte*
trx_undo_rec_get_partial_row(
/*=========================*/
	byte*		ptr,	/*!< in: remaining part in update undo log
				record of a suitable type, at the start of
				the stored index columns;
				NOTE that this copy of the undo log record must
				be preserved as long as the partial row is
				used, as we do NOT copy the data in the
				record! */
	dict_index_t*	index,	/*!< in: clustered index */
	dtuple_t**	row,	/*!< out, own: partial row */
	ibool		ignore_prefix, /*!< in: flag to indicate if we
				expect blob prefixes in undo. Used
				only in the assertion. */
	mem_heap_t*	heap)	/*!< in: memory heap from which the memory
				needed is allocated */
{
	const byte*	end_ptr;
	ulint		row_len;

	ut_ad(index);
	ut_ad(ptr);
	ut_ad(row);
	ut_ad(heap);
	ut_ad(dict_index_is_clust(index));

	row_len = dict_table_get_n_cols(index->table);

	*row = dtuple_create(heap, row_len);

	dict_table_copy_types(*row, index->table);

	end_ptr = ptr + mach_read_from_2(ptr);
	ptr += 2;

	while (ptr != end_ptr) {
		dfield_t*		dfield;
		byte*			field;
		ulint			field_no;
		const dict_col_t*	col;
		ulint			col_no;
		ulint			len;
		ulint			orig_len;

		ptr = trx_undo_update_rec_get_field_no(ptr, &field_no);

		col = dict_index_get_nth_col(index, field_no);
		col_no = dict_col_get_no(col);

		ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);

		dfield = dtuple_get_nth_field(*row, col_no);

		dfield_set_data(dfield, field, len);

		if (len != UNIV_SQL_NULL
		    && len >= UNIV_EXTERN_STORAGE_FIELD) {
			dfield_set_len(dfield,
				       len - UNIV_EXTERN_STORAGE_FIELD);
			dfield_set_ext(dfield);
			/* If the prefix of this column is indexed,
			ensure that enough prefix is stored in the
			undo log record. */
			if (!ignore_prefix && col->ord_part) {
				ut_a(dfield_get_len(dfield)
				     >= 2 * BTR_EXTERN_FIELD_REF_SIZE);
				ut_a(dict_table_get_format(index->table)
				     >= DICT_TF_FORMAT_ZIP
				     || dfield_get_len(dfield)
				     >= REC_MAX_INDEX_COL_LEN
				     + BTR_EXTERN_FIELD_REF_SIZE);
			}
		}
	}

	return(ptr);
}
示例#5
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);
}
示例#6
0
/**************************************************************************
Reports in the undo log of an update or delete marking of a clustered index
record. */
static
ulint
trx_undo_page_report_modify(
/*========================*/
					/* out: byte offset of the inserted
					undo log entry on the page if succeed,
					0 if fail */
	page_t*		undo_page,	/* in: undo log page */
	trx_t*		trx,		/* in: transaction */
	dict_index_t*	index,		/* in: clustered index where update or
					delete marking is done */
	rec_t*		rec,		/* in: clustered index record which
					has NOT yet been modified */
	const ulint*	offsets,	/* in: rec_get_offsets(rec, index) */
	upd_t*		update,		/* in: update vector which tells the
					columns to be updated; in the case of
					a delete, this should be set to NULL */
	ulint		cmpl_info,	/* in: compiler info on secondary
					index updates */
	mtr_t*		mtr)		/* in: mtr */
{
	dict_table_t*	table;
	upd_field_t*	upd_field;
	ulint		first_free;
	byte*		ptr;
	ulint		len;
	byte*		field;
	ulint		flen;
	ulint		pos;
	dulint		roll_ptr;
	dulint		trx_id;
	ulint		bits;
	ulint		col_no;
	byte*		old_ptr;
	ulint		type_cmpl;
	byte*		type_cmpl_ptr;
	ulint		i;

	ut_a(index->type & DICT_CLUSTERED);
	ut_ad(rec_offs_validate(rec, index, offsets));
	ut_ad(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
			       + TRX_UNDO_PAGE_TYPE) == TRX_UNDO_UPDATE);
	table = index->table;

	first_free = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
				      + TRX_UNDO_PAGE_FREE);
	ptr = undo_page + first_free;

	ut_ad(first_free <= UNIV_PAGE_SIZE);

	if (trx_undo_left(undo_page, ptr) < 50) {

		/* NOTE: the value 50 must be big enough so that the general
		fields written below fit on the undo log page */

		return(0);
	}

	/* Reserve 2 bytes for the pointer to the next undo log record */
	ptr += 2;

	/* Store first some general parameters to the undo log */

	if (update) {
		if (rec_get_deleted_flag(rec, dict_table_is_comp(table))) {
			type_cmpl = TRX_UNDO_UPD_DEL_REC;
		} else {
			type_cmpl = TRX_UNDO_UPD_EXIST_REC;
		}
	} else {
		type_cmpl = TRX_UNDO_DEL_MARK_REC;
	}

	type_cmpl = type_cmpl | (cmpl_info * TRX_UNDO_CMPL_INFO_MULT);

	mach_write_to_1(ptr, type_cmpl);

	type_cmpl_ptr = ptr;

	ptr++;
	len = mach_dulint_write_much_compressed(ptr, trx->undo_no);
	ptr += len;

	len = mach_dulint_write_much_compressed(ptr, table->id);
	ptr += len;

	/*----------------------------------------*/
	/* Store the state of the info bits */

	bits = rec_get_info_bits(rec, dict_table_is_comp(table));
	mach_write_to_1(ptr, bits);
	ptr += 1;

	/* Store the values of the system columns */
	field = rec_get_nth_field(rec, offsets,
				  dict_index_get_sys_col_pos(
					  index, DATA_TRX_ID), &len);
	ut_ad(len == DATA_TRX_ID_LEN);
	trx_id = trx_read_trx_id(field);
	field = rec_get_nth_field(rec, offsets,
				  dict_index_get_sys_col_pos(
					  index, DATA_ROLL_PTR), &len);
	ut_ad(len == DATA_ROLL_PTR_LEN);
	roll_ptr = trx_read_roll_ptr(field);

	len = mach_dulint_write_compressed(ptr, trx_id);
	ptr += len;

	len = mach_dulint_write_compressed(ptr, roll_ptr);
	ptr += len;

	/*----------------------------------------*/
	/* Store then the fields required to uniquely determine the
	record which will be modified in the clustered index */

	for (i = 0; i < dict_index_get_n_unique(index); i++) {

		field = rec_get_nth_field(rec, offsets, i, &flen);

		if (trx_undo_left(undo_page, ptr) < 4) {

			return(0);
		}

		len = mach_write_compressed(ptr, flen);
		ptr += len;

		if (flen != UNIV_SQL_NULL) {
			if (trx_undo_left(undo_page, ptr) < flen) {

				return(0);
			}

			ut_memcpy(ptr, field, flen);
			ptr += flen;
		}
	}

	/*----------------------------------------*/
	/* Save to the undo log the old values of the columns to be updated. */

	if (update) {
		if (trx_undo_left(undo_page, ptr) < 5) {

			return(0);
		}

		len = mach_write_compressed(ptr, upd_get_n_fields(update));
		ptr += len;

		for (i = 0; i < upd_get_n_fields(update); i++) {

			upd_field = upd_get_nth_field(update, i);
			pos = upd_field->field_no;

			/* Write field number to undo log */
			if (trx_undo_left(undo_page, ptr) < 5) {

				return(0);
			}

			len = mach_write_compressed(ptr, pos);
			ptr += len;

			/* Save the old value of field */
			field = rec_get_nth_field(rec, offsets, pos, &flen);

			if (trx_undo_left(undo_page, ptr) < 5) {

				return(0);
			}

			if (rec_offs_nth_extern(offsets, pos)) {
				/* If a field has external storage, we add
				to flen the flag */

				len = mach_write_compressed(
					ptr,
					UNIV_EXTERN_STORAGE_FIELD + flen);

				/* Notify purge that it eventually has to
				free the old externally stored field */

				trx->update_undo->del_marks = TRUE;

				*type_cmpl_ptr = *type_cmpl_ptr
					| TRX_UNDO_UPD_EXTERN;
			} else {
				len = mach_write_compressed(ptr, flen);
			}

			ptr += len;

			if (flen != UNIV_SQL_NULL) {
				if (trx_undo_left(undo_page, ptr) < flen) {

					return(0);
				}

				ut_memcpy(ptr, field, flen);
				ptr += flen;
			}
		}
	}

	/*----------------------------------------*/
	/* In the case of a delete marking, and also in the case of an update
	where any ordering field of any index changes, store the values of all
	columns which occur as ordering fields in any index. This info is used
	in the purge of old versions where we use it to build and search the
	delete marked index records, to look if we can remove them from the
	index tree. Note that starting from 4.0.14 also externally stored
	fields can be ordering in some index. But we always store at least
	384 first bytes locally to the clustered index record, which means
	we can construct the column prefix fields in the index from the
	stored data. */

	if (!update || !(cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {

		trx->update_undo->del_marks = TRUE;

		if (trx_undo_left(undo_page, ptr) < 5) {

			return(0);
		}

		old_ptr = ptr;

		/* Reserve 2 bytes to write the number of bytes the stored
		fields take in this undo record */

		ptr += 2;

		for (col_no = 0; col_no < dict_table_get_n_cols(table);
		     col_no++) {

			const dict_col_t*	col
				= dict_table_get_nth_col(table, col_no);

			if (col->ord_part > 0) {

				pos = dict_index_get_nth_col_pos(index,
								 col_no);

				/* Write field number to undo log */
				if (trx_undo_left(undo_page, ptr) < 5) {

					return(0);
				}

				len = mach_write_compressed(ptr, pos);
				ptr += len;

				/* Save the old value of field */
				field = rec_get_nth_field(rec, offsets, pos,
							  &flen);

				if (trx_undo_left(undo_page, ptr) < 5) {

					return(0);
				}

				len = mach_write_compressed(ptr, flen);
				ptr += len;

				if (flen != UNIV_SQL_NULL) {
					if (trx_undo_left(undo_page, ptr)
					    < flen) {

						return(0);
					}

					ut_memcpy(ptr, field, flen);
					ptr += flen;
				}
			}
		}

		mach_write_to_2(old_ptr, ptr - old_ptr);
	}

	/*----------------------------------------*/
	/* Write pointers to the previous and the next undo log records */
	if (trx_undo_left(undo_page, ptr) < 2) {

		return(0);
	}

	mach_write_to_2(ptr, first_free);
	ptr += 2;
	mach_write_to_2(undo_page + first_free, ptr - undo_page);

	mach_write_to_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE,
			ptr - undo_page);

	/* Write to the REDO log about this change in the UNDO log */

	trx_undof_page_add_undo_rec_log(undo_page, first_free,
					ptr - undo_page, mtr);
	return(first_free);
}
示例#7
0
文件: row0row.c 项目: OPSF/uClinux
dtuple_t*
row_build(
/*======*/
				/* out, own: row built; see the NOTE below! */
	ulint		type,	/* in: ROW_COPY_POINTERS, ROW_COPY_DATA, or
				ROW_COPY_ALSO_EXTERNALS, 
				the two last copy also the data fields to
				heap as the first only places pointers to
				data fields on the index page, and thus is
				more efficient */
	dict_index_t*	index,	/* in: clustered index */
	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! */
	mem_heap_t*	heap)	/* in: memory heap from which the memory
				needed is allocated */
{
	dtuple_t*	row;
	dict_table_t*	table;
	dict_field_t*	ind_field;
	dict_col_t*	col;
	dfield_t*	dfield;
	ulint		n_fields;
	byte*		field;
	ulint		len;
	ulint		row_len;
	byte*		buf; 
	ulint		i;
	
	ut_ad(index && rec && heap);
	ut_ad(index->type & DICT_CLUSTERED);

	if (type != ROW_COPY_POINTERS) {
		/* Take a copy of rec to heap */
		buf = mem_heap_alloc(heap, rec_get_size(rec));
		rec = rec_copy(buf, rec);
	}

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

	row = dtuple_create(heap, row_len);

	dtuple_set_info_bits(row, rec_get_info_bits(rec));
	
	n_fields = dict_index_get_n_fields(index);

	ut_ad(n_fields == rec_get_n_fields(rec));

	dict_table_copy_types(row, table);

	for (i = 0; i < n_fields; i++) {
	        ind_field = dict_index_get_nth_field(index, i);

		if (ind_field->prefix_len == 0) {

		        col = dict_field_get_col(ind_field);
			dfield = dtuple_get_nth_field(row,
						dict_col_get_no(col));
			field = rec_get_nth_field(rec, i, &len);

			if (type == ROW_COPY_ALSO_EXTERNALS
			    && rec_get_nth_field_extern_bit(rec, i)) {

			        field = btr_rec_copy_externally_stored_field(
							rec, i, &len, heap);
			}

			dfield_set_data(dfield, field, len);
		}
	}

	ut_ad(dtuple_check_typed(row));

	return(row);
}