google::cloud::spanner::ResultSourceInterface Class Reference

Defines the interface for RowStream implementations. More...

#include <google/cloud/spanner/results.h>

Public Member Functions
virtual	~ResultSourceInterface ()=default
virtual StatusOr< spanner::Row >	NextRow ()=0
	Returns the next row in the stream. More...
virtual absl::optional< google::spanner::v1::ResultSetMetadata >	Metadata ()=0
	Returns metadata about the result set, such as the field types and the transaction id created by the request. More...
virtual absl::optional< google::spanner::v1::ResultSetStats >	Stats () const =0
	Returns statistics about the result set, such as the number of rows, and the query plan used to compute the results. More...

Detailed Description

Defines the interface for RowStream implementations.

The RowStream class represents a stream of Rows returned from spanner::Client::Read() or spanner::Client::ExecuteQuery(). There are different implementations depending the the RPC. Applications can also mock this class when testing their code and mocking the spanner::Client behavior.

Constructor & Destructor Documentation

~ResultSourceInterface()

virtual google::cloud::spanner::ResultSourceInterface::~ResultSourceInterface ( )

virtualdefault

Member Function Documentation

Metadata()

virtual absl::optional< google::spanner::v1::ResultSetMetadata > google::cloud::spanner::ResultSourceInterface::Metadata ( )

pure virtual

Returns metadata about the result set, such as the field types and the transaction id created by the request.

See also

https://cloud.google.com/spanner/docs/reference/rpc/google.spanner.v1#resultsetmetadata for more information.

NextRow()

virtual StatusOr< spanner::Row > google::cloud::spanner::ResultSourceInterface::NextRow ( )

pure virtual

Returns the next row in the stream.

Returns

if the stream is interrupted due to a failure the StatusOr<spanner::Row> contains the error. The function returns a successful StatusOr<> with an empty spanner::Row to indicate end-of-stream.

Stats()

virtual absl::optional< google::spanner::v1::ResultSetStats > google::cloud::spanner::ResultSourceInterface::Stats ( ) const

pure virtual

Returns statistics about the result set, such as the number of rows, and the query plan used to compute the results.

See also

https://cloud.google.com/spanner/docs/reference/rpc/google.spanner.v1#resultsetstats for more information.