ydb::TopicSimpleWriteSession Class Reference

#include <userver/ydb/topic.hpp>

Detailed Description

Simple write session used to write messages to a topic without manually handling write session events.

This is a userver-native analogue of YDB SDK ISimpleBlockingWriteSession: methods may wait for YDB flow-control continuation tokens, but waiting suspends the current coroutine instead of blocking an OS thread. It wraps a single IWriteSession; its simple API does not expose the native event loop or acknowledgments.

See also

https://ydb.tech/docs/en/reference/ydb-sdk/topic#write

Definition at line 137 of file topic.hpp.

Public Member Functions
	TopicSimpleWriteSession (const TopicSimpleWriteSession &)=delete
TopicSimpleWriteSession &	operator= (const TopicSimpleWriteSession &)=delete
	TopicSimpleWriteSession (TopicSimpleWriteSession &&) noexcept
TopicSimpleWriteSession &	operator= (TopicSimpleWriteSession &&) noexcept
bool	Write (NYdb::NTopic::TWriteMessage &&message, NYdb::TTransactionBase *tx=nullptr, engine::Deadline deadline={})
	Write a single message.
bool	Write (std::string_view data, std::optional< std::uint64_t > seq_no=std::nullopt, std::optional< std::chrono::system_clock::time_point > create_timestamp=std::nullopt, engine::Deadline deadline={})
	Write a single message using basic message options.
std::uint64_t	GetInitSeqNo (engine::Deadline deadline={})
	Wait until initial SeqNo is discovered from the server.
bool	Close (std::chrono::milliseconds timeout)
	Close the write session.
bool	IsAlive () const noexcept
	Returns true if the write session is alive and active.
NYdb::NTopic::IWriteSession &	GetNativeTopicWriteSession ()
	Get native write session.

Member Function Documentation

Close()

bool ydb::TopicSimpleWriteSession::Close

(

std::chrono::milliseconds

timeout

)

Close the write session.

Waits for all in-flight messages to be acknowledged. Force closes after timeout.

Returns

true if all writes were completed and acknowledged. Returns false if the timeout expired and some writes were aborted; in that case their delivery is not guaranteed and should be handled as an application-level delivery failure.

GetNativeTopicWriteSession()

NYdb::NTopic::IWriteSession & ydb::TopicSimpleWriteSession::GetNativeTopicWriteSession

(

)

Get native write session.

Warning

Use with care! Facilities from userver/drivers/subscribable_futures.hpp can help with non-blocking wait operations.

Write()

bool ydb::TopicSimpleWriteSession::Write	(	NYdb::NTopic::TWriteMessage &&	message,
		NYdb::TTransactionBase *	tx = nullptr,
		engine::Deadline	deadline = {} )

Write a single message.

Waits until YDB provides a continuation token or until deadline.

Returns

true if the message was enqueued for writing, false if the deadline was reached or the session was closed before a token arrived.

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

• userver/ydb/topic.hpp