tech.ydb.coordination

Interface CoordinationSession

All Superinterfaces:

AutoCloseable

public interface CoordinationSession
extends AutoCloseable

Author:

Alexandr Gorshein

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	CoordinationSession.State

Method Summary

Modifier and Type	Method and Description
CompletableFuture<tech.ydb.core.Result<SemaphoreLease>>	acquireEphemeralSemaphore(String name, boolean exclusive, byte[] data, Duration timeout) Acquire an ephemeral semaphore.
default CompletableFuture<tech.ydb.core.Result<SemaphoreLease>>	acquireEphemeralSemaphore(String name, boolean exclusive, Duration timeout) Acquire an ephemeral semaphore.
CompletableFuture<tech.ydb.core.Result<SemaphoreLease>>	acquireSemaphore(String name, long count, byte[] data, Duration timeout) Acquire an semaphore.
default CompletableFuture<tech.ydb.core.Result<SemaphoreLease>>	acquireSemaphore(String name, long count, Duration timeout) Acquire a semaphore.
void	addStateListener(Consumer<CoordinationSession.State> listener)
default void	close()
CompletableFuture<tech.ydb.core.Status>	connect() Establish new bidirectional grpc stream
default CompletableFuture<tech.ydb.core.Status>	createSemaphore(String name, long limit) Create a new semaphore.
CompletableFuture<tech.ydb.core.Status>	createSemaphore(String name, long limit, byte[] data) Create a new semaphore.
default CompletableFuture<tech.ydb.core.Status>	deleteSemaphore(String name) Remove a semaphore.
CompletableFuture<tech.ydb.core.Status>	deleteSemaphore(String name, boolean force) Remove a semaphore.
CompletableFuture<tech.ydb.core.Result<SemaphoreDescription>>	describeSemaphore(String name, DescribeSemaphoreMode mode)
long	getId() Current session identifier.
CoordinationSession.State	getState()
void	removeStateListener(Consumer<CoordinationSession.State> listener)
CompletableFuture<tech.ydb.core.Status>	stop() Send message to grpc server to stop stream.
CompletableFuture<tech.ydb.core.Status>	updateSemaphore(String name, byte[] data) Update data attached to the semaphore.
CompletableFuture<tech.ydb.core.Result<SemaphoreWatcher>>	watchSemaphore(String name, DescribeSemaphoreMode describeMode, WatchSemaphoreMode watchMode)

Method Detail

connect

CompletableFuture<tech.ydb.core.Status> connect()

Establish new bidirectional grpc stream

Returns:

Future with status of operation

stop

CompletableFuture<tech.ydb.core.Status> stop()

Send message to grpc server to stop stream. If server doesn't close connection, client cancels it itself

Returns:

Future with status of operation

getId

long getId()

Current session identifier. If the connection wasn't established session will return -1

Returns:

active session identifier

getState

CoordinationSession.State getState()

addStateListener

void addStateListener(Consumer<CoordinationSession.State> listener)

removeStateListener

void removeStateListener(Consumer<CoordinationSession.State> listener)

close

default void close()

Specified by:

close in interface AutoCloseable

createSemaphore

CompletableFuture<tech.ydb.core.Status> createSemaphore(String name,
                                                        long limit,
                                                        byte[] data)

Create a new semaphore. This operation doesn't change internal state of the coordination session so one session may be used for creating different semaphores

Parameters:

name - Name of the semaphore to create

limit - Number of tokens that may be acquired by sessions

data - User-defined data that will be attached to the semaphore

Returns:

Future with status of operation. If there already was a semaphore with such a name, you get ALREADY_EXISTS status.

updateSemaphore

CompletableFuture<tech.ydb.core.Status> updateSemaphore(String name,
                                                        byte[] data)

Update data attached to the semaphore. This operation doesn't change internal state of the coordination session so one session may be used for updating different semaphores

Parameters:

name - Name of the semaphore to update

data - User-defined data that will be attached to the semaphore

Returns:

future with status of operation

deleteSemaphore

CompletableFuture<tech.ydb.core.Status> deleteSemaphore(String name,
                                                        boolean force)

Remove a semaphore. This operation doesn't change internal state of the coordination session so one session may be used for removing different semaphores

Parameters:

name - Name of the semaphore to remove

force - Will delete semaphore even if it's currently acquired by sessions

Returns:

Future with status of operation.

acquireSemaphore

CompletableFuture<tech.ydb.core.Result<SemaphoreLease>> acquireSemaphore(String name,
                                                                         long count,
                                                                         byte[] data,
                                                                         Duration timeout)

Acquire an semaphore.

WARNING: a single session can acquire only one semaphore in one moment

Later requests override previous operations with the same semaphore, e.g. to reduce acquired count, change timeout or attached data

Parameters:

name - Name of the semaphore to acquire

count - Number of tokens to acquire on the semaphore

timeout - Duration after which operation will fail if it's still waiting in the waiters queue

data - User-defined binary data that may be attached to the operation

Returns:

If there is a semaphore with name, future will return a semaphore lease object. If there is no such a semaphore, future will complete exceptionally with UnexpectedResultException.

acquireEphemeralSemaphore

CompletableFuture<tech.ydb.core.Result<SemaphoreLease>> acquireEphemeralSemaphore(String name,
                                                                                  boolean exclusive,
                                                                                  byte[] data,
                                                                                  Duration timeout)

Acquire an ephemeral semaphore. Ephemeral semaphores are created with the first acquire operation and automatically deleted with the last release operation.

WARNING: a single session can acquire only one semaphore in one moment

Later requests override previous operations with the same semaphore, e.g. to reduce acquired count, change timeout or attached data

Parameters:

name - Name of the semaphore to acquire

exclusive - Flag of exclusive acquiring

timeout - Duration after which operation will fail if it's still waiting in the waiters queue

data - User-defined binary data that may be attached to the operation

Returns:

future with a semaphore lease object

describeSemaphore

CompletableFuture<tech.ydb.core.Result<SemaphoreDescription>> describeSemaphore(String name,
                                                                                DescribeSemaphoreMode mode)

watchSemaphore

CompletableFuture<tech.ydb.core.Result<SemaphoreWatcher>> watchSemaphore(String name,
                                                                         DescribeSemaphoreMode describeMode,
                                                                         WatchSemaphoreMode watchMode)

createSemaphore

default CompletableFuture<tech.ydb.core.Status> createSemaphore(String name,
                                                                long limit)

Create a new semaphore. This operation doesn't change internal state of the coordination session so one session may be used for creating different semaphores

Parameters:

name - Name of the semaphore to create

limit - Number of tokens that may be acquired by sessions

Returns:

future with status of operation

deleteSemaphore

default CompletableFuture<tech.ydb.core.Status> deleteSemaphore(String name)

Remove a semaphore. This operation doesn't change internal state of the coordination session so one session may be used for removing different semaphores

Parameters:

name - Name of the semaphore to remove

Returns:

Future with status of operation.

acquireSemaphore

default CompletableFuture<tech.ydb.core.Result<SemaphoreLease>> acquireSemaphore(String name,
                                                                                 long count,
                                                                                 Duration timeout)

Acquire a semaphore.

WARNING: a single session can acquire only one semaphore in one moment

Later requests override previous operations with the same semaphore, e.g. to reduce acquired count, change timeout or attached data

Parameters:

name - Name of the semaphore to acquire

count - Number of tokens to acquire on the semaphore

timeout - Duration after which operation will fail if it's still waiting in the waiters queue

Returns:

future with a semaphore lease object

acquireEphemeralSemaphore

default CompletableFuture<tech.ydb.core.Result<SemaphoreLease>> acquireEphemeralSemaphore(String name,
                                                                                          boolean exclusive,
                                                                                          Duration timeout)

Acquire an ephemeral semaphore. Ephemeral semaphores are created with the first acquire operation and automatically deleted with the last release operation.

WARNING: a single session can acquire only one semaphore in one moment

Later requests override previous operations with the same semaphore, e.g. to reduce acquired count, change timeout or attached data

Parameters:

name - Name of the semaphore to acquire

exclusive - Flag of exclusive acquiring

timeout - Duration after which operation will fail if it's still waiting in the waiters queue

Returns:

future with a semaphore lease object