Package com.google.cloud.spanner
Interface AsyncTransactionManager.AsyncTransactionFunction<I,O>
- Type Parameters:
I
-O
-
- Enclosing interface:
- AsyncTransactionManager
public static interface AsyncTransactionManager.AsyncTransactionFunction<I,O>
Each step in a transaction chain is defined by an
AsyncTransactionManager.AsyncTransactionFunction
. It receives
a TransactionContext
and the output value of the previous transaction step as its input
parameters. The method should return an ApiFuture
that will return the result of this
step.-
Method Summary
Modifier and TypeMethodDescriptioncom.google.api.core.ApiFuture<O>
apply
(TransactionContext txn, I input) This method is called when this transaction step is executed.
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Method Details
-
apply
This method is called when this transaction step is executed. The input value is the result of the previous step, and this method will only be called if the previous step executed successfully.- Parameters:
txn
- theTransactionContext
that can be used to execute statements.input
- the result of the previous transaction step.- Returns:
- an
ApiFuture
that will return the result of this step, and that will be the input of the next transaction step. This method should never returnnull
. Instead, if the method does not have a return value, the method should return ApiFutures#immediateFuture(null). - Throws:
Exception
-