聊聊shardingjdbc的XATransactionManager

序

本文主要研究一下 sharding-jdbc 的 XATransactionManager

XATransactionManager

incubator-shardingsphere-4.0.0-RC1/sharding-transaction/sharding-transaction-2pc/sharding-transaction-xa/sharding-transaction-xa-spi/src/main/java/org/apache/shardingsphere/transaction/xa/spi/XATransactionManager.java

public interface XATransactionManager extends AutoCloseable {
    
    /**
     * Initialize XA transaction manager.
     */
    void init();
    
    /**
     * Register recovery resource.
     *
     * @param dataSourceName data source name
     * @param xaDataSource XA data source
     */
    void registerRecoveryResource(String dataSourceName, XADataSource xaDataSource);
    
    /**
     * Remove recovery resource.
     *
     * @param dataSourceName data source name
     * @param xaDataSource   XA data source
     */
    void removeRecoveryResource(String dataSourceName, XADataSource xaDataSource);
    
    /**
     * Enlist single XA resource.
     * 
     * @param singleXAResource single XA resource
     */
    void enlistResource(SingleXAResource singleXAResource);
    
    /**
     * Get transaction manager.
     * 
     * @return transaction manager
     */
    TransactionManager getTransactionManager();}

• XATransactionManager 继承了 AutoCloseable 接口，它定义了 init、registerRecoveryResource、removeRecoveryResource、enlistResource、getTransactionManager 方法

AtomikosTransactionManager

incubator-shardingsphere-4.0.0-RC1/sharding-transaction/sharding-transaction-2pc/sharding-transaction-xa/sharding-transaction-xa-core/src/main/java/org/apache/shardingsphere/transaction/xa/manager/atomikos/AtomikosTransactionManager.java

public final class AtomikosTransactionManager implements XATransactionManager {private final UserTransactionManager transactionManager = new UserTransactionManager();
    
    private final UserTransactionService userTransactionService = new UserTransactionServiceImp();
    
    @Override
    public void init() {userTransactionService.init();
    }
    
    @Override
    public void registerRecoveryResource(final String dataSourceName, final XADataSource xaDataSource) {userTransactionService.registerResource(new AtomikosXARecoverableResource(dataSourceName, xaDataSource));
    }
    
    @Override
    public void removeRecoveryResource(final String dataSourceName, final XADataSource xaDataSource) {userTransactionService.removeResource(new AtomikosXARecoverableResource(dataSourceName, xaDataSource));
    }
    
    @Override
    @SneakyThrows
    public void enlistResource(final SingleXAResource xaResource) {transactionManager.getTransaction().enlistResource(xaResource);
    }
    
    @Override
    public TransactionManager getTransactionManager() {return transactionManager;}
    
    @Override
    public void close() {userTransactionService.shutdown(true);
    }
}

• AtomikosTransactionManager 实现了 XATransactionManager 接口，它内置了 UserTransactionManager、UserTransactionServiceImp 属性
• init 方法执行 userTransactionService.init()；registerRecoveryResource 方法执行 userTransactionService.registerResource(new AtomikosXARecoverableResource(dataSourceName, xaDataSource))；removeRecoveryResource 方法执行 userTransactionService.removeResource(new AtomikosXARecoverableResource(dataSourceName, xaDataSource))
• enlistResource 执行 transactionManager.getTransaction().enlistResource(xaResource)；getTransactionManager 返回 UserTransactionManager；close 方法执行 userTransactionService.shutdown(true)

AtomikosTransactionManagerTest

incubator-shardingsphere-4.0.0-RC1/sharding-transaction/sharding-transaction-2pc/sharding-transaction-xa/sharding-transaction-xa-core/src/test/java/org/apache/shardingsphere/transaction/xa/manager/atomikos/AtomikosTransactionManagerTest.java

@RunWith(MockitoJUnitRunner.class)
public final class AtomikosTransactionManagerTest {private AtomikosTransactionManager atomikosTransactionManager = new AtomikosTransactionManager();
    
    @Mock
    private UserTransactionManager userTransactionManager;
    
    @Mock
    private UserTransactionService userTransactionService;
    
    @Mock
    private XADataSource xaDataSource;
    
    @Before
    public void setUp() {ReflectiveUtil.setProperty(atomikosTransactionManager, "transactionManager", userTransactionManager);
        ReflectiveUtil.setProperty(atomikosTransactionManager, "userTransactionService", userTransactionService);
    }
    
    @Test
    public void assertInit() {atomikosTransactionManager.init();
        verify(userTransactionService).init();}
    
    @Test
    public void assertRegisterRecoveryResource() {atomikosTransactionManager.registerRecoveryResource("ds1", xaDataSource);
        verify(userTransactionService).registerResource(any(AtomikosXARecoverableResource.class));
    }
    
    @Test
    public void assertRemoveRecoveryResource() {atomikosTransactionManager.removeRecoveryResource("ds1", xaDataSource);
        verify(userTransactionService).removeResource(any(AtomikosXARecoverableResource.class));
    }
    
    @Test
    public void assertEnListResource() throws Exception {SingleXAResource singleXAResource = mock(SingleXAResource.class);
        Transaction transaction = mock(Transaction.class);
        when(userTransactionManager.getTransaction()).thenReturn(transaction);
        atomikosTransactionManager.enlistResource(singleXAResource);
        verify(transaction).enlistResource(singleXAResource);
    }
    
    @Test
    public void assertTransactionManager() {assertThat(atomikosTransactionManager.getTransactionManager(), CoreMatchers.<TransactionManager>is(userTransactionManager));
    }
    
    @Test
    public void assertClose() {atomikosTransactionManager.close();
        verify(userTransactionService).shutdown(true);
    }
}

• 这里 mock 了 userTransactionManager、userTransactionService、xaDataSource

小结

XATransactionManager 继承了 AutoCloseable 接口，它定义了 init、registerRecoveryResource、removeRecoveryResource、enlistResource、getTransactionManager 方法

doc

• XATransactionManager