google::cloud::spanner::ReadPartition Class Reference

The ReadPartition class is a regular type that represents a single slice of a parallel Read operation. More...

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

Public Member Functions
	ReadPartition ()=default
	Constructs an instance of ReadPartition that does not specify any table or columns to be read. More...
std::string	TableName () const
std::vector< std::string >	ColumnNames () const
google::cloud::spanner::ReadOptions	ReadOptions () const
Copy and move.
	ReadPartition (ReadPartition const &)=default
	ReadPartition (ReadPartition &&)=default
ReadPartition &	operator= (ReadPartition const &)=default
ReadPartition &	operator= (ReadPartition &&)=default

Friends
StatusOr< std::string >	SerializeReadPartition (ReadPartition const &read_partition)
	Serializes an instance of ReadPartition to a string of bytes. More...
StatusOr< ReadPartition >	DeserializeReadPartition (std::string const &serialized_read_partition)
	Deserializes the provided string into a ReadPartition. More...
Equality
bool	operator== (ReadPartition const &lhs, ReadPartition const &rhs)
bool	operator!= (ReadPartition const &lhs, ReadPartition const &rhs)

Detailed Description

The ReadPartition class is a regular type that represents a single slice of a parallel Read operation.

Instances of ReadPartition are created by Client::PartitionRead. Once created, ReadPartition objects can be serialized, transmitted to separate processes, and used to read data in parallel using Client::Read. If data_boost is set, those requests will be executed using the independent compute resources of Cloud Spanner Data Boost.

Constructor & Destructor Documentation

ReadPartition() [1/3]

google::cloud::spanner::ReadPartition::ReadPartition ( )

default

Constructs an instance of ReadPartition that does not specify any table or columns to be read.

ReadPartition() [2/3]

google::cloud::spanner::ReadPartition::ReadPartition ( ReadPartition const &  )

default

ReadPartition() [3/3]

google::cloud::spanner::ReadPartition::ReadPartition ( ReadPartition &&  )

default

Member Function Documentation

ColumnNames()

std::vector< std::string > google::cloud::spanner::ReadPartition::ColumnNames ( ) const

inline

operator=() [1/2]

ReadPartition & google::cloud::spanner::ReadPartition::operator= ( ReadPartition &&  )

default

operator=() [2/2]

ReadPartition & google::cloud::spanner::ReadPartition::operator= ( ReadPartition const &  )

default

ReadOptions()

google::cloud::spanner::ReadOptions google::cloud::spanner::ReadPartition::ReadOptions

(

)

const

TableName()

std::string google::cloud::spanner::ReadPartition::TableName ( ) const

inline

Friends And Related Function Documentation

DeserializeReadPartition

StatusOr< ReadPartition > DeserializeReadPartition ( std::string const &  serialized_read_partition )

friend

Deserializes the provided string into a ReadPartition.

The serialized_read_partition argument must be a string that was previously returned by a call to SerializeReadPartition().

Note

The serialized string may contain NUL and other non-printable characters. Therefore, callers should avoid formatted IO functions that may incorrectly reformat the string data.

Parameters

serialized_read_partition

- string representation to be deserialized.

Example

  google::cloud::StatusOr<google::cloud::spanner::ReadPartition>
  ReceiveReadPartitionFromRemoteMachine() {
    std::string serialized_partition = Receive();
    return google::cloud::spanner::DeserializeReadPartition(
        serialized_partition);
  }

operator!=

bool operator!= ( ReadPartition const &  lhs, ReadPartition const &  rhs  )

friend

operator==

bool operator== ( ReadPartition const &  lhs, ReadPartition const &  rhs  )

friend

SerializeReadPartition

StatusOr< std::string > SerializeReadPartition ( ReadPartition const &  read_partition )

friend

Serializes an instance of ReadPartition to a string of bytes.

The serialized string of bytes is suitable for writing to disk or transmission to another process.

Note

The serialized string may contain NUL and other non-printable characters. Therefore, callers should avoid formatted IO functions that may incorrectly reformat the string data.

Parameters

read_partition

- instance to be serialized.

Example

    namespace spanner = ::google::cloud::spanner;
    google::cloud::StatusOr<std::string> serialized_partition =
        spanner::SerializeReadPartition(partition);
    if (!serialized_partition) throw std::move(serialized_partition).status();
    std::string const& bytes = *serialized_partition;
    // `bytes` contains the serialized data, which may contain NULs and other
    // non-printable characters.
    SendBinaryStringData(bytes);