com.bigdata.btree.isolation

Class TestAccount.TxAccount

java.lang.Object

com.bigdata.btree.isolation.TestAccount.TxAccount

Enclosing class:

TestAccount

public static class TestAccount.TxAccount
extends Object

A transactional view of an TestAccount.Account. Each transaction has its own transaction local state (low, high, and change). All operations within a transaction are applied to the TestAccount.TxAccount. If the transaction validates and commits, then the net change in the balance due to the operations on the transaction is applied to the TestAccount.Account balance.

Version:

$Id$

Author:

Bryan Thompson

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TestAccount.TxAccount.OverdraftException

Constructor Summary

Constructors

Constructor and Description
TestAccount.TxAccount(TestAccount.Account account)

Method Summary

Methods

Modifier and Type	Method and Description
void	commit() Validate against the current account balance and commit the change to the account.
void	credit(long cents) Credit the account.
void	debit(long cents) Debit the account.
String	toString()
boolean	validate() Validate the transaction against the current account balance.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

TestAccount.TxAccount

public TestAccount.TxAccount(TestAccount.Account account)

Method Detail

credit

public void credit(long cents)

Credit the account.

Parameters:

cents - The amount.

debit

public void debit(long cents)
           throws TestAccount.TxAccount.OverdraftException

Debit the account.

Parameters:

cents - The amount.

Throws:

TestAccount.TxAccount.OverdraftException - iff an overdraft must result.

toString

public String toString()

Overrides:

toString in class Object

validate

public boolean validate()

Validate the transaction against the current account balance.

Note: Validation is currently invoked from within the commit(), which handles atomicity with respect to the account balance.

commit

public void commit()

Validate against the current account balance and commit the change to the account.

Note: This validate + commit operation needs to be atomic. That is achieved here by synchronizing on the account. However that technique will not work in a distributed system.