Golang TableDescriptor.Validate方法代碼示例

func (s *Server) getTableDesc(database string, qname parser.QualifiedName) (
	*structured.TableDescriptor, error) {
	var err error
	qname, err = s.normalizeTableName(database, qname)
	if err != nil {
		return nil, err
	}
	dbID, err := s.lookupDatabase(qname.Database())
	if err != nil {
		return nil, err
	}
	gr, err := s.db.Get(keys.MakeNameMetadataKey(dbID, qname.Table()))
	if err != nil {
		return nil, err
	}
	if !gr.Exists() {
		return nil, fmt.Errorf("table \"%s\" does not exist", qname)
	}
	descKey := gr.ValueBytes()
	desc := structured.TableDescriptor{}
	if err := s.db.GetProto(descKey, &desc); err != nil {
		return nil, err
	}
	if err := desc.Validate(); err != nil {
		return nil, err
	}
	return &desc, nil
}

func (db *DB) getTableDesc(path string) (*structured.TableDescriptor, error) {
	nsID, name, err := db.lookupTable(path)
	if err != nil {
		return nil, err
	}
	if name == "" {
		return nil, fmt.Errorf("empty table name: %s", path)
	}
	gr, err := db.Get(keys.MakeNameMetadataKey(nsID, name))
	if err != nil {
		return nil, err
	}
	if !gr.Exists() {
		return nil, fmt.Errorf("unable to find table \"%s\"", path)
	}
	descKey := gr.ValueBytes()
	desc := structured.TableDescriptor{}
	if err := db.GetProto(descKey, &desc); err != nil {
		return nil, err
	}
	if err := desc.Validate(); err != nil {
		return nil, err
	}
	return &desc, nil
}

func (c *conn) getTableDesc(table *parser.TableName) (*structured.TableDescriptor, error) {
	if err := c.normalizeTableName(table); err != nil {
		return nil, err
	}
	dbID, err := c.lookupDatabase(table.Qualifier)
	if err != nil {
		return nil, err
	}
	gr, err := c.db.Get(keys.MakeNameMetadataKey(dbID, table.Name))
	if err != nil {
		return nil, err
	}
	if !gr.Exists() {
		return nil, fmt.Errorf("table \"%s\" does not exist", table)
	}
	descKey := gr.ValueBytes()
	desc := structured.TableDescriptor{}
	if err := c.db.GetProto(descKey, &desc); err != nil {
		return nil, err
	}
	if err := desc.Validate(); err != nil {
		return nil, err
	}
	return &desc, nil
}

// DropTable drops a table.
// Privileges: WRITE on table.
//   Notes: postgres allows only the table owner to DROP a table.
//          mysql requires the DROP privilege on the table.
func (p *planner) DropTable(n *parser.DropTable) (planNode, error) {
	// TODO(XisiHuang): should do truncate and delete descriptor in
	// the same txn
	for i, tableQualifiedName := range n.Names {
		if err := tableQualifiedName.NormalizeTableName(p.session.Database); err != nil {
			return nil, err
		}

		dbDesc, err := p.getDatabaseDesc(tableQualifiedName.Database())
		if err != nil {
			return nil, err
		}

		tbKey := tableKey{dbDesc.ID, tableQualifiedName.Table()}
		nameKey := tbKey.Key()
		gr, err := p.txn.Get(nameKey)
		if err != nil {
			return nil, err
		}

		if !gr.Exists() {
			if n.IfExists {
				// Noop.
				continue
			}
			// Key does not exist, but we want it to: error out.
			return nil, fmt.Errorf("table %q does not exist", tbKey.Name())
		}

		tableDesc := structured.TableDescriptor{}
		if err := p.txn.GetProto(gr.ValueBytes(), &tableDesc); err != nil {
			return nil, err
		}
		if err := tableDesc.Validate(); err != nil {
			return nil, err
		}

		if !tableDesc.HasPrivilege(p.user, parser.PrivilegeWrite) {
			return nil, fmt.Errorf("user %s does not have %s privilege on table %s",
				p.user, parser.PrivilegeWrite, tableDesc.Name)
		}

		if _, err = p.Truncate(&parser.Truncate{Tables: n.Names[i : i+1]}); err != nil {
			return nil, err
		}

		// Delete table descriptor
		descKey := gr.ValueBytes()
		b := &client.Batch{}
		b.Del(descKey)
		b.Del(nameKey)
		err = p.txn.Run(b)
		if err != nil {
			return nil, err
		}
	}
	return &valuesNode{}, nil
}

// RenameTable renames a table. Old path and new path have the form
// "<namespace>.<table>".
func (db *DB) RenameTable(oldPath, newPath string) error {
	// TODO(pmattis): Should we allow both the old and new name to exist
	// simultaneously for a period of time? The thought is to allow an
	// application to access the table via either name while the application is
	// being upgraded. Alternatively, instead of a rename table operation perhaps
	// there should be a link table operation which adds a "hard link" to the
	// table. Similar to a file, a table would not be removed until all of the
	// hard links are removed.

	oldNSID, oldName, err := db.lookupTable(oldPath)
	if err != nil {
		return err
	}
	newNSID, newName, err := db.lookupTable(newPath)
	if err != nil {
		return err
	}
	if newName == "" {
		return fmt.Errorf("empty table name: %s", newPath)
	}

	return db.Txn(func(txn *Txn) error {
		oldNameKey := keys.MakeNameMetadataKey(oldNSID, oldName)
		gr, err := txn.Get(oldNameKey)
		if err != nil {
			return err
		}
		if !gr.Exists() {
			return fmt.Errorf("unable to find table \"%s\"", oldPath)
		}
		descKey := gr.ValueBytes()
		desc := structured.TableDescriptor{}
		if err := txn.GetProto(descKey, &desc); err != nil {
			return err
		}
		desc.Name = strings.ToLower(newPath)
		if err := desc.Validate(); err != nil {
			return err
		}
		newNameKey := keys.MakeNameMetadataKey(newNSID, newName)
		b := &Batch{}
		b.Put(descKey, &desc)
		// If the new name already exists the conditional put will fail causing the
		// transaction to fail.
		b.CPut(newNameKey, descKey, nil)
		b.Del(oldNameKey)
		return txn.Commit(b)
	})
}