Implements async and sync querying against the cassandra DB with support for throttling. More...

#include <ExecutionStrategy.hpp>

Public Types
using	ResultOrErrorType = typename HandleType::ResultOrErrorType
using	StatementType = typename HandleType::StatementType
using	PreparedStatementType = typename HandleType::PreparedStatementType
using	FutureType = typename HandleType::FutureType
using	FutureWithCallbackType = typename HandleType::FutureWithCallbackType
using	ResultType = typename HandleType::ResultType
using	CompletionTokenType = boost::asio::yield_context

Public Member Functions
	DefaultExecutionStrategy (Settings const &settings, HandleType const &handle, typename BackendCountersType::PtrType counters=BackendCountersType::make())
void	sync ()
	Wait for all async writes to finish before unblocking.
bool	isTooBusy () const
ResultOrErrorType	writeSync (StatementType const &statement)
	Blocking query execution used for writing data.
template<typename... Args>
ResultOrErrorType	writeSync (PreparedStatementType const &preparedStatement, Args &&... args)
	Blocking query execution used for writing data.
template<typename... Args>
void	write (PreparedStatementType const &preparedStatement, Args &&... args)
	Non-blocking query execution used for writing data.
void	write (StatementType &&statement)
	Non-blocking query execution used for writing data.
void	write (std::vector< StatementType > &&statements)
	Non-blocking batched query execution used for writing data.
void	writeEach (std::vector< StatementType > &&statements)
	Non-blocking query execution used for writing data. Contrast with write, this method does not execute the statements in a batch.
template<typename... Args>
ResultOrErrorType	read (CompletionTokenType token, PreparedStatementType const &preparedStatement, Args &&... args)
	Coroutine-based query execution used for reading data.
ResultOrErrorType	read (CompletionTokenType token, std::vector< StatementType > const &statements)
	Coroutine-based query execution used for reading data.
ResultOrErrorType	read (CompletionTokenType token, StatementType const &statement)
	Coroutine-based query execution used for reading data.
std::vector< ResultType >	readEach (CompletionTokenType token, std::vector< StatementType > const &statements)
	Coroutine-based query execution used for reading data.
boost::json::object	stats () const
	Get statistics about the backend.

Detailed Description

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>
class data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >

Implements async and sync querying against the cassandra DB with support for throttling.

Note: A lot of the code that uses yield is repeated below. This is ok for now because we are hopefully going to be getting rid of it entirely later on.

Constructor & Destructor Documentation

◆ DefaultExecutionStrategy()

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::DefaultExecutionStrategy	(	Settings const &	settings,
		HandleType const &	handle,
		typename BackendCountersType::PtrType	counters = BackendCountersType::make() )

inline

Parameters

settings	The settings to use
handle	A handle to the cassandra database

Member Function Documentation

◆ isTooBusy()

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

bool data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::isTooBusy ( ) const

inline

Returns: true if outstanding read requests allowance is exhausted; false otherwise

◆ read() [1/3]

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

template<typename... Args>

ResultOrErrorType data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::read	(	CompletionTokenType	token,
		PreparedStatementType const &	preparedStatement,
		Args &&...	args )

inline

Coroutine-based query execution used for reading data.

Retries forever until successful or throws an exception on timeout.

Parameters

token	Completion token (yield_context)
preparedStatement	Statement to prepare and execute
args	Args to bind to the prepared statement

Exceptions

DatabaseTimeout on timeout

Returns: ResultType or error wrapped in Expected

◆ read() [2/3]

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

ResultOrErrorType data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::read	(	CompletionTokenType	token,
		StatementType const &	statement )

inline

Coroutine-based query execution used for reading data.

Retries forever until successful or throws an exception on timeout.

Parameters

token	Completion token (yield_context)
statement	Statement to execute

Exceptions

DatabaseTimeout on timeout

Returns: ResultType or error wrapped in Expected

◆ read() [3/3]

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

ResultOrErrorType data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::read	(	CompletionTokenType	token,
		std::vector< StatementType > const &	statements )

inline

Coroutine-based query execution used for reading data.

Retries forever until successful or throws an exception on timeout.

Parameters

token	Completion token (yield_context)
statements	Statements to execute in a batch

Exceptions

DatabaseTimeout on timeout

Returns: ResultType or error wrapped in Expected

◆ readEach()

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

std::vector< ResultType > data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::readEach	(	CompletionTokenType	token,
		std::vector< StatementType > const &	statements )

inline

Coroutine-based query execution used for reading data.

Attempts to execute each statement. On any error the whole vector will be discarded and exception will be thrown.

Parameters

token	Completion token (yield_context)
statements	Statements to execute

Exceptions

DatabaseTimeout on db error

Returns: Vector of results

◆ write() [1/3]

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

template<typename... Args>

void data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::write	(	PreparedStatementType const &	preparedStatement,
		Args &&...	args )

inline

Non-blocking query execution used for writing data.

Retries forever with retry policy specified by AsyncExecutor

Parameters

preparedStatement	Statement to prepare and execute
args	Args to bind to the prepared statement

Exceptions

DatabaseTimeout on timeout

◆ write() [2/3]

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

void data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::write ( StatementType && statement )

inline

Non-blocking query execution used for writing data.

Retries forever with retry policy specified by AsyncExecutor

Parameters

statement Statement to execute

Exceptions

DatabaseTimeout on timeout

◆ write() [3/3]

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

void data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::write ( std::vector< StatementType > && statements )

inline

Non-blocking batched query execution used for writing data.

Retries forever with retry policy specified by AsyncExecutor.

Parameters

statements Vector of statements to execute as a batch

Exceptions

DatabaseTimeout on timeout

◆ writeEach()

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

void data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::writeEach ( std::vector< StatementType > && statements )

inline

Non-blocking query execution used for writing data. Contrast with write, this method does not execute the statements in a batch.

Retries forever with retry policy specified by AsyncExecutor.

Parameters

statements Vector of statements to execute

Exceptions

DatabaseTimeout on timeout

◆ writeSync() [1/2]

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

template<typename... Args>

ResultOrErrorType data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::writeSync	(	PreparedStatementType const &	preparedStatement,
		Args &&...	args )

inline

Blocking query execution used for writing data.

Retries forever sleeping for 5 milliseconds between attempts.

◆ writeSync() [2/2]

template<typename HandleType = Handle, SomeBackendCounters BackendCountersType = BackendCounters>

ResultOrErrorType data::cassandra::impl::DefaultExecutionStrategy< HandleType, BackendCountersType >::writeSync ( StatementType const & statement )

inline

Blocking query execution used for writing data.

Retries forever sleeping for 5 milliseconds between attempts.

The documentation for this class was generated from the following file:

/__w/clio/clio/src/data/cassandra/impl/ExecutionStrategy.hpp

Public Types

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ DefaultExecutionStrategy()

Member Function Documentation

◆ isTooBusy()

◆ read() [1/3]

◆ read() [2/3]

◆ read() [3/3]

◆ readEach()

◆ write() [1/3]

◆ write() [2/3]

◆ write() [3/3]

◆ writeEach()

◆ writeSync() [1/2]

◆ writeSync() [2/2]