Golang sql.InternalExecutor類代碼示例

// TableStats is an endpoint that returns columns, indices, and other
// relevant details for the specified table.
func (s *adminServer) TableStats(ctx context.Context, req *serverpb.TableStatsRequest) (
	*serverpb.TableStatsResponse, error,
) {
	// Get table span.
	var tableSpan roachpb.Span
	var iexecutor sql.InternalExecutor
	if err := s.server.db.Txn(func(txn *client.Txn) error {
		var err error
		tableSpan, err = iexecutor.GetTableSpan(s.getUser(req), txn, req.Database, req.Table)
		return err
	}); err != nil {
		return nil, s.serverError(err)
	}

	startKey, err := keys.Addr(tableSpan.Key)
	if err != nil {
		return nil, s.serverError(err)
	}
	endKey, err := keys.Addr(tableSpan.EndKey)
	if err != nil {
		return nil, s.serverError(err)
	}

	// Get current range descriptors for table. This is done by scanning over
	// meta2 keys for the range.
	rangeDescKVs, err := s.server.db.Scan(keys.RangeMetaKey(startKey), keys.RangeMetaKey(endKey), 0)
	if err != nil {
		return nil, s.serverError(err)
	}

	// Extract a list of node IDs from the response.
	nodeIDs := make(map[roachpb.NodeID]struct{})
	for _, kv := range rangeDescKVs {
		var rng roachpb.RangeDescriptor
		if err := kv.Value.GetProto(&rng); err != nil {
			return nil, s.serverError(err)
		}
		for _, repl := range rng.Replicas {
			nodeIDs[repl.NodeID] = struct{}{}
		}
	}

	// Construct TableStatsResponse by sending an RPC to every node involved.
	tableStatResponse := serverpb.TableStatsResponse{
		NodeCount:  int64(len(nodeIDs)),
		RangeCount: int64(len(rangeDescKVs)),
	}
	type nodeResponse struct {
		nodeID roachpb.NodeID
		resp   *serverpb.SpanStatsResponse
		err    error
	}

	// Send a SpanStats query to each node. Set a timeout on the context for
	// these queries.
	responses := make(chan nodeResponse)
	ctx, cancel := context.WithTimeout(ctx, base.NetworkTimeout)
	defer cancel()
	for nodeID := range nodeIDs {
		nodeID := nodeID
		if err := s.server.stopper.RunAsyncTask(func() {
			var spanResponse *serverpb.SpanStatsResponse
			client, err := s.server.status.dialNode(nodeID)
			if err == nil {
				req := serverpb.SpanStatsRequest{
					StartKey: startKey,
					EndKey:   endKey,
					NodeID:   nodeID.String(),
				}
				spanResponse, err = client.SpanStats(ctx, &req)
			}

			response := nodeResponse{
				nodeID: nodeID,
				resp:   spanResponse,
				err:    err,
			}
			select {
			case responses <- response:
				// Response processed.
			case <-ctx.Done():
				// Context completed, response no longer needed.
			}
		}); err != nil {
			return nil, err
		}
	}
	for remainingResponses := len(nodeIDs); remainingResponses > 0; remainingResponses-- {
		select {
		case resp := <-responses:
			// For nodes which returned an error, note that the node's data
			// is missing. For successful calls, aggregate statistics.
			if resp.err != nil {
				tableStatResponse.MissingNodes = append(
					tableStatResponse.MissingNodes,
					serverpb.TableStatsResponse_MissingNode{
						NodeID:       resp.nodeID.String(),
						ErrorMessage: resp.err.Error(),
//.........這裏部分代碼省略.........

//.........這裏部分代碼省略.........
				return nil, err
			}
			if !isDefaultNull {
				if err := scanner.Scan(row, defaultCol, &col.Default); err != nil {
					return nil, err
				}
			}
			resp.Columns = append(resp.Columns, col)
		}
	}

	// Marshal SHOW INDEX result.
	{
		const (
			nameCol      = "Name"
			uniqueCol    = "Unique"
			seqCol       = "Seq"
			columnCol    = "Column"
			directionCol = "Direction"
			storingCol   = "Storing"
		)
		scanner := makeResultScanner(r.ResultList[1].Columns)
		for _, row := range r.ResultList[1].Rows {
			// Marshal grant, splitting comma-separated privileges into a proper slice.
			var index TableDetailsResponse_Index
			if err := scanner.Scan(row, nameCol, &index.Name); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, uniqueCol, &index.Unique); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, seqCol, &index.Seq); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, columnCol, &index.Column); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, directionCol, &index.Direction); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, storingCol, &index.Storing); err != nil {
				return nil, err
			}
			resp.Indexes = append(resp.Indexes, index)
		}
	}

	// Marshal SHOW GRANTS result.
	{
		const (
			userCol       = "User"
			privilegesCol = "Privileges"
		)
		scanner := makeResultScanner(r.ResultList[2].Columns)
		for _, row := range r.ResultList[2].Rows {
			// Marshal grant, splitting comma-separated privileges into a proper slice.
			var grant TableDetailsResponse_Grant
			var privileges string
			if err := scanner.Scan(row, userCol, &grant.User); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, privilegesCol, &privileges); err != nil {
				return nil, err
			}
			grant.Privileges = strings.Split(privileges, ",")
			resp.Grants = append(resp.Grants, grant)
		}
	}

	// Get the number of ranges in the table. We get the key span for the table
	// data. Then, we count the number of ranges that make up that key span.
	{
		var iexecutor sql.InternalExecutor
		var tableSpan roachpb.Span
		if pErr := s.db.Txn(func(txn *client.Txn) *roachpb.Error {
			var pErr *roachpb.Error
			tableSpan, pErr = iexecutor.GetTableSpan(s.getUser(req), txn, escDbName, escTableName)
			return pErr
		}); pErr != nil {
			return nil, s.serverError(pErr.GoError())
		}
		tableRSpan := roachpb.RSpan{}
		var err error
		tableRSpan.Key, err = keys.Addr(tableSpan.Key)
		if err != nil {
			return nil, s.serverError(err)
		}
		tableRSpan.EndKey, err = keys.Addr(tableSpan.EndKey)
		if err != nil {
			return nil, s.serverError(err)
		}
		rangeCount, pErr := s.distSender.CountRanges(tableRSpan)
		if pErr != nil {
			return nil, s.serverError(pErr.GoError())
		}
		resp.RangeCount = rangeCount
	}

	return &resp, nil
}

//.........這裏部分代碼省略.........
		}
	}

	// Marshal SHOW GRANTS result.
	{
		const (
			userCol       = "User"
			privilegesCol = "Privileges"
		)
		scanner := makeResultScanner(r.ResultList[2].Columns)
		for _, row := range r.ResultList[2].Rows {
			// Marshal grant, splitting comma-separated privileges into a proper slice.
			var grant serverpb.TableDetailsResponse_Grant
			var privileges string
			if err := scanner.Scan(row, userCol, &grant.User); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, privilegesCol, &privileges); err != nil {
				return nil, err
			}
			grant.Privileges = strings.Split(privileges, ",")
			resp.Grants = append(resp.Grants, grant)
		}
	}

	// Marshal SHOW CREATE TABLE result.
	{
		const createTableCol = "CreateTable"
		showResult := r.ResultList[3]
		if len(showResult.Rows) != 1 {
			return nil, s.serverErrorf("CreateTable response not available.")
		}

		scanner := makeResultScanner(showResult.Columns)
		var createStmt string
		if err := scanner.Scan(showResult.Rows[0], createTableCol, &createStmt); err != nil {
			return nil, err
		}

		resp.CreateTableStatement = createStmt
	}

	// Get the number of ranges in the table. We get the key span for the table
	// data. Then, we count the number of ranges that make up that key span.
	{
		var iexecutor sql.InternalExecutor
		var tableSpan roachpb.Span
		if err := s.server.db.Txn(func(txn *client.Txn) error {
			var err error
			tableSpan, err = iexecutor.GetTableSpan(s.getUser(req), txn, escDBName, escTableName)
			return err
		}); err != nil {
			return nil, s.serverError(err)
		}
		tableRSpan := roachpb.RSpan{}
		var err error
		tableRSpan.Key, err = keys.Addr(tableSpan.Key)
		if err != nil {
			return nil, s.serverError(err)
		}
		tableRSpan.EndKey, err = keys.Addr(tableSpan.EndKey)
		if err != nil {
			return nil, s.serverError(err)
		}
		rangeCount, err := s.server.distSender.CountRanges(tableRSpan)
		if err != nil {
			return nil, s.serverError(err)
		}
		resp.RangeCount = rangeCount
	}

	// Query the zone configuration for this table.
	{
		path, err := s.queryDescriptorIDPath(session, []string{escDBName, escTableName})
		if err != nil {
			return nil, s.serverError(err)
		}

		id, zone, zoneExists, err := s.queryZonePath(session, path)
		if err != nil {
			return nil, s.serverError(err)
		}

		if !zoneExists {
			zone = config.DefaultZoneConfig()
		}
		resp.ZoneConfig = zone

		switch id {
		case path[1]:
			resp.ZoneConfigLevel = serverpb.ZoneConfigurationLevel_DATABASE
		case path[2]:
			resp.ZoneConfigLevel = serverpb.ZoneConfigurationLevel_TABLE
		default:
			resp.ZoneConfigLevel = serverpb.ZoneConfigurationLevel_CLUSTER
		}
	}

	return &resp, nil
}