Package com.google.cloud.spanner

Interface AsyncTransactionManager

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

DelayedAsyncTransactionManager

public interface AsyncTransactionManager
extends AutoCloseable

An interface for managing the life cycle of a read write transaction including all its retries. See TransactionContext for a description of transaction semantics.

At any point in time there can be at most one active transaction in this manager. When that transaction is committed, if it fails with an ABORTED error, calling resetForRetryAsync() would create a new AsyncTransactionManager.TransactionContextFuture. The newly created transaction would use the same session thus increasing its lock priority. If the transaction is committed successfully, or is rolled back or commit fails with any error other than ABORTED, the manager is considered complete and no further transactions are allowed to be created in it.

Every AsyncTransactionManager should either be committed or rolled back. Failure to do so can cause resources to be leaked and deadlocks. Easiest way to guarantee this is by calling close() in a finally block.

See Also:

• DatabaseClient.transactionManagerAsync(TransactionOption...)

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	AsyncTransactionManager.AsyncTransactionFunction<I,O>	Each step in a transaction chain is defined by an AsyncTransactionManager.AsyncTransactionFunction.
static interface	AsyncTransactionManager.AsyncTransactionStep<I,O>	AsyncTransactionManager.AsyncTransactionStep is returned by AsyncTransactionManager.TransactionContextFuture.then(AsyncTransactionFunction, Executor) and AsyncTransactionManager.AsyncTransactionStep.then(AsyncTransactionFunction, Executor) and allows transaction steps that should be executed serially to be chained together.
static interface	AsyncTransactionManager.CommitTimestampFuture	ApiFuture that returns the commit Timestamp of a Cloud Spanner transaction that is executed using an AsyncTransactionManager.
static interface	AsyncTransactionManager.TransactionContextFuture	ApiFuture that returns a TransactionContext and that supports chaining of multiple AsyncTransactionManager.TransactionContextFutures to form a transaction.

Method Summary

Modifier and Type	Method	Description
AsyncTransactionManager.TransactionContextFuture	beginAsync()	Creates a new read write transaction.
AsyncTransactionManager.TransactionContextFuture	beginAsync(AbortedException exception)	Initializes a new read-write transaction that is a retry of a previously aborted transaction.
void	close()	Closes the manager.
com.google.api.core.ApiFuture<Void>	closeAsync()	Closes the transaction manager.
com.google.api.core.ApiFuture<CommitResponse>	getCommitResponse()	Returns the CommitResponse of this transaction.
TransactionManager.TransactionState	getState()	Returns the state of the transaction.
AsyncTransactionManager.TransactionContextFuture	resetForRetryAsync()	Creates a new transaction for retry.
com.google.api.core.ApiFuture<Void>	rollbackAsync()	Rolls back the currently active transaction.

Method Details

beginAsync

AsyncTransactionManager.TransactionContextFuture beginAsync()

Creates a new read write transaction. This must be called before doing any other operation and can only be called once. To create a new transaction for subsequent retries, see resetForRetryAsync().

beginAsync

AsyncTransactionManager.TransactionContextFuture beginAsync(AbortedException exception)

Initializes a new read-write transaction that is a retry of a previously aborted transaction. This method must be called before performing any operations, and it can only be invoked once per transaction lifecycle.

This method should only be used when multiplexed sessions are enabled to create a retry for a previously aborted transaction. This method can be used instead of resetForRetryAsync() to create a retry. Using this method or resetForRetryAsync() will have the same effect. You must pass in the AbortedException from the previous attempt to preserve the transaction's priority.

For regular sessions, this behaves the same as beginAsync().

rollbackAsync

com.google.api.core.ApiFuture<Void> rollbackAsync()

Rolls back the currently active transaction. In most cases there should be no need to call this explicitly since close() would automatically roll back any active transaction.

resetForRetryAsync

AsyncTransactionManager.TransactionContextFuture resetForRetryAsync()

Creates a new transaction for retry. This should only be called if the previous transaction failed with ABORTED. In all other cases, this will throw an IllegalStateException. Users should backoff before calling this method. Backoff delay is specified by SpannerException.getRetryDelayInMillis() on the SpannerException throw by the previous commit call.

getState

TransactionManager.TransactionState getState()

Returns the state of the transaction.

getCommitResponse

com.google.api.core.ApiFuture<CommitResponse> getCommitResponse()

Returns the CommitResponse of this transaction.

close

void close()

Closes the manager. If there is an active transaction, it will be rolled back. Underlying session will be released back to the session pool.

Specified by:

close in interface AutoCloseable

closeAsync

com.google.api.core.ApiFuture<Void> closeAsync()

Closes the transaction manager. If there is an active transaction, it will be rolled back. The underlying session will be released back to the session pool. The returned ApiFuture is done when the transaction (if any) has been rolled back.