public interface TransactionManager 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 #resetForRetry() would create a new TransactionContext. 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
manager is considered complete and no further transactions are allowed to be created in it.
TransactionManager 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#transactionManager()
public abstract TransactionContext begin()
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 #resetForRetry().
public abstract 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.
public abstract void commit()
Commits the currently active transaction. If the transaction was already aborted, then this would throw an AbortedException.
public abstract CommitResponse getCommitResponse()
Returns the CommitResponse of this transaction.
public abstract Timestamp getCommitTimestamp()
Returns the commit timestamp if the transaction committed successfully otherwise it will throw
public abstract TransactionManager.TransactionState getState()
Returns the state of the transaction.
public abstract TransactionContext resetForRetry()
Creates a new transaction for retry. This should only be called if the previous transaction
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
throw by the previous commit call.
public abstract void rollback()
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.