Functional interface for executing a read/write transaction asynchronously that returns a
result of type R.
Type Parameter
Name
Description
R
Methods
doWorkAsync(TransactionContext txn)
public abstract ApiFuture<R> doWorkAsync(TransactionContext txn)
Performs a single transaction attempt. All reads/writes should be performed using
txn.
Implementations of this method should not attempt to commit the transaction directly:
returning normally will result in the runner attempting to commit the transaction once the
returned future completes, retrying on abort.
In most cases, the implementation will not need to catch SpannerExceptions from
Spanner operations, instead letting these propagate to the framework. The transaction runner
will take appropriate action based on the type of exception. In particular, implementations
should never catch an exception of type Code#ABORTED: these indicate that some reads
may have returned inconsistent data and the transaction attempt must be aborted.