Golang sqlbase.TableDescriptor類代碼示例

func makeFKDeleteHelper(
	txn *client.Txn,
	table sqlbase.TableDescriptor,
	otherTables tableLookupsByID,
	colMap map[sqlbase.ColumnID]int,
) (fkDeleteHelper, error) {
	var fks fkDeleteHelper
	for _, idx := range table.AllNonDropIndexes() {
		for _, ref := range idx.ReferencedBy {
			if otherTables[ref.Table].isAdding {
				// We can assume that a table being added but not yet public is empty,
				// and thus does not need to be checked for FK violations.
				continue
			}
			fk, err := makeBaseFKHelper(txn, otherTables, idx, ref, colMap)
			if err == errSkipUnusedFK {
				continue
			}
			if err != nil {
				return fks, err
			}
			if fks == nil {
				fks = make(fkDeleteHelper)
			}
			fks[idx.ID] = append(fks[idx.ID], fk)
		}
	}
	return fks, nil
}

// writeTableDesc implements the SchemaAccessor interface.
func (p *planner) writeTableDesc(tableDesc *sqlbase.TableDescriptor) error {
	if isVirtualDescriptor(tableDesc) {
		panic(fmt.Sprintf("Virtual Descriptors cannot be stored, found: %v", tableDesc))
	}
	return p.txn.Put(sqlbase.MakeDescMetadataKey(tableDesc.GetID()),
		sqlbase.WrapDescriptor(tableDesc))
}

// GetKeysForTableDescriptor retrieves the KV keys corresponding
// to the zone, name and descriptor of a table.
func GetKeysForTableDescriptor(
	tableDesc *sqlbase.TableDescriptor,
) (zoneKey roachpb.Key, nameKey roachpb.Key, descKey roachpb.Key) {
	zoneKey = sqlbase.MakeZoneKey(tableDesc.ID)
	nameKey = sqlbase.MakeNameMetadataKey(tableDesc.ParentID, tableDesc.GetName())
	descKey = sqlbase.MakeDescMetadataKey(tableDesc.ID)
	return
}

// makeRowDeleter creates a rowDeleter for the given table.
//
// The returned rowDeleter contains a fetchCols field that defines the
// expectation of which values are passed as values to deleteRow. Any column
// passed in requestedCols will be included in fetchCols.
func makeRowDeleter(
	txn *client.Txn,
	tableDesc *sqlbase.TableDescriptor,
	fkTables tableLookupsByID,
	requestedCols []sqlbase.ColumnDescriptor,
	checkFKs bool,
) (rowDeleter, error) {
	indexes := tableDesc.Indexes
	for _, m := range tableDesc.Mutations {
		if index := m.GetIndex(); index != nil {
			indexes = append(indexes, *index)
		}
	}

	fetchCols := requestedCols[:len(requestedCols):len(requestedCols)]
	fetchColIDtoRowIndex := colIDtoRowIndexFromCols(fetchCols)

	maybeAddCol := func(colID sqlbase.ColumnID) error {
		if _, ok := fetchColIDtoRowIndex[colID]; !ok {
			col, err := tableDesc.FindColumnByID(colID)
			if err != nil {
				return err
			}
			fetchColIDtoRowIndex[col.ID] = len(fetchCols)
			fetchCols = append(fetchCols, *col)
		}
		return nil
	}
	for _, colID := range tableDesc.PrimaryIndex.ColumnIDs {
		if err := maybeAddCol(colID); err != nil {
			return rowDeleter{}, err
		}
	}
	for _, index := range indexes {
		for _, colID := range index.ColumnIDs {
			if err := maybeAddCol(colID); err != nil {
				return rowDeleter{}, err
			}
		}
	}

	rd := rowDeleter{
		helper:               rowHelper{tableDesc: tableDesc, indexes: indexes},
		fetchCols:            fetchCols,
		fetchColIDtoRowIndex: fetchColIDtoRowIndex,
	}
	if checkFKs {
		var err error
		if rd.fks, err = makeFKDeleteHelper(txn, *tableDesc, fkTables, fetchColIDtoRowIndex); err != nil {
			return rowDeleter{}, err
		}
	}

	return rd, nil
}

func filterTableState(tableDesc *sqlbase.TableDescriptor) error {
	switch {
	case tableDesc.Dropped():
		return errTableDropped
	case tableDesc.Adding():
		return errTableAdding
	case tableDesc.State != sqlbase.TableDescriptor_PUBLIC:
		return errors.Errorf("table in unknown state: %s", tableDesc.State.String())
	}
	return nil
}

func convertBatchError(tableDesc *sqlbase.TableDescriptor, b *client.Batch) error {
	origPErr := b.MustPErr()
	if origPErr.Index == nil {
		return origPErr.GoError()
	}
	index := origPErr.Index.Index
	if index >= int32(len(b.Results)) {
		panic(fmt.Sprintf("index %d outside of results: %+v", index, b.Results))
	}
	result := b.Results[index]
	var alloc sqlbase.DatumAlloc
	if _, ok := origPErr.GetDetail().(*roachpb.ConditionFailedError); ok {
		for _, row := range result.Rows {
			// TODO(dan): There's too much internal knowledge of the sql table
			// encoding here (and this callsite is the only reason
			// DecodeIndexKeyPrefix is exported). Refactor this bit out.
			indexID, key, err := sqlbase.DecodeIndexKeyPrefix(&alloc, tableDesc, row.Key)
			if err != nil {
				return err
			}
			index, err := tableDesc.FindIndexByID(indexID)
			if err != nil {
				return err
			}
			vals, err := sqlbase.MakeEncodedKeyVals(tableDesc, index.ColumnIDs)
			if err != nil {
				return err
			}
			dirs := make([]encoding.Direction, 0, len(index.ColumnIDs))
			for _, dir := range index.ColumnDirections {
				convertedDir, err := dir.ToEncodingDirection()
				if err != nil {
					return err
				}
				dirs = append(dirs, convertedDir)
			}
			if _, err := sqlbase.DecodeKeyVals(&alloc, vals, dirs, key); err != nil {
				return err
			}
			decodedVals := make([]parser.Datum, len(vals))
			var da sqlbase.DatumAlloc
			for i, val := range vals {
				err := val.EnsureDecoded(&da)
				if err != nil {
					return err
				}
				decodedVals[i] = val.Datum
			}
			return sqlbase.NewUniquenessConstraintViolationError(index, decodedVals)
		}
	}
	return origPErr.GoError()
}

func forEachIndexInTable(
	table *sqlbase.TableDescriptor, fn func(*sqlbase.IndexDescriptor) error,
) error {
	if table.IsPhysicalTable() {
		if err := fn(&table.PrimaryIndex); err != nil {
			return err
		}
	}
	for i := range table.Indexes {
		if err := fn(&table.Indexes[i]); err != nil {
			return err
		}
	}
	return nil
}

// deleteIndexMutationsWithReversedColumns deletes index mutations with a
// different mutationID than the schema changer and a reference to one of the
// reversed columns.
func (sc *SchemaChanger) deleteIndexMutationsWithReversedColumns(
	desc *sqlbase.TableDescriptor, columns map[string]struct{},
) {
	newMutations := make([]sqlbase.DescriptorMutation, 0, len(desc.Mutations))
	for _, mutation := range desc.Mutations {
		if mutation.MutationID != sc.mutationID {
			if idx := mutation.GetIndex(); idx != nil {
				deleteMutation := false
				for _, name := range idx.ColumnNames {
					if _, ok := columns[name]; ok {
						// Such an index mutation has to be with direction ADD and
						// in the DELETE_ONLY state. Live indexes referencing live
						// columns cannot be deleted and thus never have direction
						// DROP. All mutations with the ADD direction start off in
						// the DELETE_ONLY state.
						if mutation.Direction != sqlbase.DescriptorMutation_ADD ||
							mutation.State != sqlbase.DescriptorMutation_DELETE_ONLY {
							panic(fmt.Sprintf("mutation in bad state: %+v", mutation))
						}
						log.Warningf(context.TODO(), "delete schema change mutation: %+v", mutation)
						deleteMutation = true
						break
					}
				}
				if deleteMutation {
					continue
				}
			}
		}
		newMutations = append(newMutations, mutation)
	}
	// Reset mutations.
	desc.Mutations = newMutations
}

func convertBackfillError(tableDesc *sqlbase.TableDescriptor, b *client.Batch) error {
	// A backfill on a new schema element has failed and the batch contains
	// information useful in printing a sensible error. However
	// convertBatchError() will only work correctly if the schema elements are
	// "live" in the tableDesc. Apply the mutations belonging to the same
	// mutationID to make all the mutations live in tableDesc. Note: this
	// tableDesc is not written to the k:v store.
	mutationID := tableDesc.Mutations[0].MutationID
	for _, mutation := range tableDesc.Mutations {
		if mutation.MutationID != mutationID {
			// Mutations are applied in a FIFO order. Only apply the first set
			// of mutations if they have the mutation ID we're looking for.
			break
		}
		tableDesc.MakeMutationComplete(mutation)
	}
	return convertBatchError(tableDesc, b)
}

func makeColIDtoRowIndex(
	row planNode, desc *sqlbase.TableDescriptor,
) (map[sqlbase.ColumnID]int, error) {
	columns := row.Columns()
	colIDtoRowIndex := make(map[sqlbase.ColumnID]int, len(columns))
	for i, column := range columns {
		s, idx, err := desc.FindColumnByNormalizedName(parser.ReNormalizeName(column.Name))
		if err != nil {
			return nil, err
		}
		switch s {
		case sqlbase.DescriptorActive:
			colIDtoRowIndex[desc.Columns[idx].ID] = i
		case sqlbase.DescriptorIncomplete:
			colIDtoRowIndex[desc.Mutations[idx].GetColumn().ID] = i
		default:
			panic("unreachable")
		}
	}
	return colIDtoRowIndex, nil
}

// tablesNeededForFKs calculates the IDs of the additional TableDescriptors that
// will be needed for FK checking delete and/or insert operations on `table`.
//
// NB: the returned map's values are *not* set -- higher level calling code, eg
// in planner, should fill the map's values by acquiring leases. This function
// is essentially just returning a slice of IDs, but the empty map can be filled
// in place and reused, avoiding a second allocation.
func tablesNeededForFKs(table sqlbase.TableDescriptor, usage FKCheck) tableLookupsByID {
	var ret tableLookupsByID
	for _, idx := range table.AllNonDropIndexes() {
		if usage != CheckDeletes && idx.ForeignKey.IsSet() {
			if ret == nil {
				ret = make(tableLookupsByID)
			}
			ret[idx.ForeignKey.Table] = tableLookup{}
		}
		if usage != CheckInserts {
			for _, idx := range table.AllNonDropIndexes() {
				for _, ref := range idx.ReferencedBy {
					if ret == nil {
						ret = make(tableLookupsByID)
					}
					ret[ref.Table] = tableLookup{}
				}
			}
		}
	}
	return ret
}

func (sc *SchemaChanger) maybeWriteResumeSpan(
	txn *client.Txn,
	tableDesc *sqlbase.TableDescriptor,
	resume roachpb.Span,
	mutationIdx int,
	lastCheckpoint *time.Time,
) error {
	checkpointInterval := checkpointInterval
	if sc.testingKnobs.WriteCheckpointInterval > 0 {
		checkpointInterval = sc.testingKnobs.WriteCheckpointInterval
	}
	if timeutil.Since(*lastCheckpoint) < checkpointInterval {
		return nil
	}
	tableDesc.Mutations[mutationIdx].ResumeSpan = resume
	txn.SetSystemConfigTrigger()
	if err := txn.Put(sqlbase.MakeDescMetadataKey(tableDesc.GetID()),
		sqlbase.WrapDescriptor(tableDesc)); err != nil {
		return err
	}
	*lastCheckpoint = timeutil.Now()
	return nil
}

func (p *planner) processColumns(
	tableDesc *sqlbase.TableDescriptor, node parser.UnresolvedNames,
) ([]sqlbase.ColumnDescriptor, error) {
	if node == nil {
		// VisibleColumns is used here to prevent INSERT INTO <table> VALUES (...)
		// (as opposed to INSERT INTO <table> (...) VALUES (...)) from writing
		// hidden columns. At present, the only hidden column is the implicit rowid
		// primary key column.
		return tableDesc.VisibleColumns(), nil
	}

	cols := make([]sqlbase.ColumnDescriptor, len(node))
	colIDSet := make(map[sqlbase.ColumnID]struct{}, len(node))
	for i, n := range node {
		c, err := n.NormalizeUnqualifiedColumnItem()
		if err != nil {
			return nil, err
		}

		if len(c.Selector) > 0 {
			return nil, util.UnimplementedWithIssueErrorf(8318, "compound types not supported yet: %q", n)
		}

		col, err := tableDesc.FindActiveColumnByName(c.ColumnName)
		if err != nil {
			return nil, err
		}

		if _, ok := colIDSet[col.ID]; ok {
			return nil, fmt.Errorf("multiple assignments to the same column %q", n)
		}
		colIDSet[col.ID] = struct{}{}
		cols[i] = col
	}

	return cols, nil
}

func makeFKInsertHelper(
	txn *client.Txn,
	table sqlbase.TableDescriptor,
	otherTables tableLookupsByID,
	colMap map[sqlbase.ColumnID]int,
) (fkInsertHelper, error) {
	var fks fkInsertHelper
	for _, idx := range table.AllNonDropIndexes() {
		if idx.ForeignKey.IsSet() {
			fk, err := makeBaseFKHelper(txn, otherTables, idx, idx.ForeignKey, colMap)
			if err == errSkipUnusedFK {
				continue
			}
			if err != nil {
				return fks, err
			}
			if fks == nil {
				fks = make(fkInsertHelper)
			}
			fks[idx.ID] = append(fks[idx.ID], fk)
		}
	}
	return fks, nil
}

// runBackfill runs the backfill for the schema changer.
func (sc *SchemaChanger) runBackfill(lease *sqlbase.TableDescriptor_SchemaChangeLease) error {
	if err := sc.ExtendLease(lease); err != nil {
		return err
	}

	// Mutations are applied in a FIFO order. Only apply the first set of
	// mutations. Collect the elements that are part of the mutation.
	var droppedColumnDescs []sqlbase.ColumnDescriptor
	var droppedIndexDescs []sqlbase.IndexDescriptor
	var addedColumnDescs []sqlbase.ColumnDescriptor
	var addedIndexDescs []sqlbase.IndexDescriptor
	// Indexes within the Mutations slice for checkpointing.
	mutationSentinel := -1
	var columnMutationIdx, addedIndexMutationIdx, droppedIndexMutationIdx int

	var tableDesc *sqlbase.TableDescriptor
	if err := sc.db.Txn(context.TODO(), func(txn *client.Txn) error {
		var err error
		tableDesc, err = sqlbase.GetTableDescFromID(txn, sc.tableID)
		return err
	}); err != nil {
		return err
	}
	// Short circuit the backfill if the table has been deleted.
	if tableDesc.Dropped() {
		return nil
	}
	version := tableDesc.Version
	for i, m := range tableDesc.Mutations {
		if m.MutationID != sc.mutationID {
			break
		}
		switch m.Direction {
		case sqlbase.DescriptorMutation_ADD:
			switch t := m.Descriptor_.(type) {
			case *sqlbase.DescriptorMutation_Column:
				addedColumnDescs = append(addedColumnDescs, *t.Column)
				if columnMutationIdx == mutationSentinel {
					columnMutationIdx = i
				}
			case *sqlbase.DescriptorMutation_Index:
				addedIndexDescs = append(addedIndexDescs, *t.Index)
				if addedIndexMutationIdx == mutationSentinel {
					addedIndexMutationIdx = i
				}
			default:
				return errors.Errorf("unsupported mutation: %+v", m)
			}

		case sqlbase.DescriptorMutation_DROP:
			switch t := m.Descriptor_.(type) {
			case *sqlbase.DescriptorMutation_Column:
				droppedColumnDescs = append(droppedColumnDescs, *t.Column)
				if columnMutationIdx == mutationSentinel {
					columnMutationIdx = i
				}
			case *sqlbase.DescriptorMutation_Index:
				droppedIndexDescs = append(droppedIndexDescs, *t.Index)
				if droppedIndexMutationIdx == mutationSentinel {
					droppedIndexMutationIdx = i
				}
			default:
				return errors.Errorf("unsupported mutation: %+v", m)
			}
		}
	}

	// First drop indexes, then add/drop columns, and only then add indexes.

	// Drop indexes.
	if err := sc.truncateIndexes(
		lease, version, droppedIndexDescs, droppedIndexMutationIdx,
	); err != nil {
		return err
	}

	// Add and drop columns.
	if err := sc.truncateAndBackfillColumns(
		lease, version, addedColumnDescs, droppedColumnDescs, columnMutationIdx,
	); err != nil {
		return err
	}

	// Add new indexes.
	if err := sc.backfillIndexes(
		lease, version, addedIndexDescs, addedIndexMutationIdx,
	); err != nil {
		return err
	}

	return nil
}