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本文主要研究一下sharding-jdbc的ShardingTransactionManager
ShardingTransactionManager
incubator-shardingsphere-4.0.0-RC1/sharding-transaction/sharding-transaction-core/src/main/java/org/apache/shardingsphere/transaction/spi/ShardingTransactionManager.java
public interface ShardingTransactionManager extends AutoCloseable {
/**
* Initialize sharding transaction manager.
*
* @param databaseType database type
* @param resourceDataSources resource data sources
*/
void init(DatabaseType databaseType, Collection resourceDataSources);
/**
* Get transaction type.
*
* @return transaction type
*/
TransactionType getTransactionType();
/**
* Judge is in transaction or not.
*
* @return in transaction or not
*/
boolean isInTransaction();
/**
* Get transactional connection.
*
* @param dataSourceName data source name
* @return connection
* @throws SQLException SQL exception
*/
Connection getConnection(String dataSourceName) throws SQLException;
/**
* Begin transaction.
*/
void begin();
/**
* Commit transaction.
*/
void commit();
/**
* Rollback transaction.
*/
void rollback();
} - ShardingTransactionManager继承了AutoCloseable接口，它定义了init、getTransactionType、isInTransaction、getConnection、begin、commit、rollback方法
XAShardingTransactionManager
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/XAShardingTransactionManager.java
public final class XAShardingTransactionManager implements ShardingTransactionManager {
private final Map singleXADataSourceMap = new HashMap<>();
private final XATransactionManager xaTransactionManager = XATransactionManagerLoader.getInstance().getTransactionManager();
private ThreadLocal> enlistedXAResource = new ThreadLocal>() {
@Override
public List initialValue() {
return new LinkedList<>();
}
};
@Override
public void init(final DatabaseType databaseType, final Collection resourceDataSources) {
for (ResourceDataSource each : resourceDataSources) {
DataSource dataSource = each.getDataSource();
if (dataSource instanceof AtomikosDataSourceBean) {
continue;
}
SingleXADataSource singleXADataSource = new SingleXADataSource(databaseType, each.getUniqueResourceName(), dataSource);
singleXADataSourceMap.put(each.getOriginalName(), singleXADataSource);
xaTransactionManager.registerRecoveryResource(each.getUniqueResourceName(), singleXADataSource.getXaDataSource());
}
xaTransactionManager.init();
}
@Override
public TransactionType getTransactionType() {
return TransactionType.XA;
}
@SneakyThrows
@Override
public boolean isInTransaction() {
return Status.STATUS_NO_TRANSACTION != xaTransactionManager.getTransactionManager().getStatus();
}
@SneakyThrows
@Override
public Connection getConnection(final String dataSourceName) {
SingleXAConnection singleXAConnection = singleXADataSourceMap.get(dataSourceName).getXAConnection();
if (!enlistedXAResource.get().contains(dataSourceName)) {
xaTransactionManager.enlistResource(singleXAConnection.getXAResource());
enlistedXAResource.get().add(dataSourceName);
}
return singleXAConnection.getConnection();
}
@SneakyThrows
@Override
public void begin() {
xaTransactionManager.getTransactionManager().begin();
}
@SneakyThrows
@Override
public void commit() {
try {
xaTransactionManager.getTransactionManager().commit();
} finally {
enlistedXAResource.remove();
}
}
@SneakyThrows
@Override
public void rollback() {
try {
xaTransactionManager.getTransactionManager().rollback();
} finally {
enlistedXAResource.remove();
}
}
@Override
public void close() throws Exception {
for (SingleXADataSource each : singleXADataSourceMap.values()) {
xaTransactionManager.removeRecoveryResource(each.getResourceName(), each.getXaDataSource());
}
singleXADataSourceMap.clear();
xaTransactionManager.close();
enlistedXAResource = null;
}
} - XAShardingTransactionManager实现了ShardingTransactionManager接口，它拥有singleXADataSourceMap、xaTransactionManager、enlistedXAResource三个属性，其init方法对这三个属性进行了初始化
- getTransactionType方法返回的是TransactionType.XA；isInTransaction方法则依据xaTransactionManager.getTransactionManager().getStatus()来判断；getConnection方法从singleXADataSourceMap取出singleXAConnection，然后执行其getConnection方法
- begin方法执行的是xaTransactionManager.getTransactionManager().begin()；commit方法则调用了xaTransactionManager.getTransactionManager().commit()，其会在finally中执行enlistedXAResource.remove()；rollback方法调用了xaTransactionManager.getTransactionManager().rollback()，其也在finally中执行enlistedXAResource.remove()；close方法则执行xaTransactionManager.removeRecoveryResource、singleXADataSourceMap.clear()、xaTransactionManager.close()
XAShardingTransactionManagerTest
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/XAShardingTransactionManagerTest.java
@RunWith(MockitoJUnitRunner.class)
public final class XAShardingTransactionManagerTest {
private XAShardingTransactionManager xaShardingTransactionManager = new XAShardingTransactionManager();
@Mock
private XATransactionManager xaTransactionManager;
@Mock
private TransactionManager transactionManager;
@Before
public void setUp() {
when(xaTransactionManager.getTransactionManager()).thenReturn(transactionManager);
ReflectiveUtil.setProperty(xaShardingTransactionManager, "xaTransactionManager", xaTransactionManager);
}
@Test
public void assertGetTransactionType() {
assertThat(xaShardingTransactionManager.getTransactionType(), is(TransactionType.XA));
}
@Test
public void assertRegisterXATransactionalDataSources() {
Collection resourceDataSources = createResourceDataSources(DruidXADataSource.class, DatabaseType.MySQL);
xaShardingTransactionManager.init(DatabaseType.MySQL, resourceDataSources);
for (ResourceDataSource each : resourceDataSources) {
verify(xaTransactionManager).registerRecoveryResource(each.getUniqueResourceName(), (XADataSource) each.getDataSource());
}
}
@Test
public void assertRegisterAtomikosDataSourceBeans() {
xaShardingTransactionManager.init(DatabaseType.MySQL, createAtomikosDataSourceBeanResource());
verify(xaTransactionManager, times(0)).registerRecoveryResource(anyString(), any(XADataSource.class));
}
@Test
public void assertRegisterNoneXATransactionalDAtaSources() {
Collection resourceDataSources = createResourceDataSources(HikariDataSource.class, DatabaseType.MySQL);
xaShardingTransactionManager.init(DatabaseType.MySQL, resourceDataSources);
Map cachedXADatasourceMap = getCachedSingleXADataSourceMap();
assertThat(cachedXADatasourceMap.size(), is(2));
}
@Test
public void assertIsInTransaction() throws SystemException {
when(transactionManager.getStatus()).thenReturn(Status.STATUS_ACTIVE);
assertTrue(xaShardingTransactionManager.isInTransaction());
}
@Test
public void assertIsNotInTransaction() throws SystemException {
when(transactionManager.getStatus()).thenReturn(Status.STATUS_NO_TRANSACTION);
assertFalse(xaShardingTransactionManager.isInTransaction());
}
@Test
public void assertGetConnection() {
setCachedSingleXADataSourceMap("ds1");
Connection actual = xaShardingTransactionManager.getConnection("ds1");
assertThat(actual, instanceOf(Connection.class));
verify(xaTransactionManager).enlistResource(any(SingleXAResource.class));
}
@Test
public void assertGetConnectionWithoutEnlist() {
setCachedSingleXADataSourceMap("ds1");
Connection actual = xaShardingTransactionManager.getConnection("ds1");
assertThat(actual, instanceOf(Connection.class));
xaShardingTransactionManager.getConnection("ds1");
assertThat(actual, instanceOf(Connection.class));
verify(xaTransactionManager).enlistResource(any(SingleXAResource.class));
}
@Test
public void assertClose() throws Exception {
setCachedSingleXADataSourceMap("ds1");
xaShardingTransactionManager.close();
Map cachedSingleXADataSourceMap = getCachedSingleXADataSourceMap();
verify(xaTransactionManager).removeRecoveryResource(anyString(), any(XADataSource.class));
assertThat(cachedSingleXADataSourceMap.size(), is(0));
}
@SneakyThrows
@SuppressWarnings("unchecked")
private Map getCachedSingleXADataSourceMap() {
Field field = xaShardingTransactionManager.getClass().getDeclaredField("singleXADataSourceMap");
field.setAccessible(true);
return (Map) field.get(xaShardingTransactionManager);
}
@SneakyThrows
private void setCachedSingleXADataSourceMap(final String datasourceName) {
Field field = xaShardingTransactionManager.getClass().getDeclaredField("singleXADataSourceMap");
field.setAccessible(true);
field.set(xaShardingTransactionManager, createMockSingleXADataSourceMap(datasourceName));
}
@SneakyThrows
private Map createMockSingleXADataSourceMap(final String datasourceName) {
SingleXADataSource singleXADataSource = mock(SingleXADataSource.class);
SingleXAConnection singleXAConnection = mock(SingleXAConnection.class);
XADataSource xaDataSource = mock(XADataSource.class);
SingleXAResource singleXAResource = mock(SingleXAResource.class);
Connection connection = mock(Connection.class);
when(singleXAConnection.getConnection()).thenReturn(connection);
when(singleXAConnection.getXAResource()).thenReturn(singleXAResource);
when(singleXADataSource.getXAConnection()).thenReturn(singleXAConnection);
when(singleXADataSource.getResourceName()).thenReturn(datasourceName);
when(singleXADataSource.getXaDataSource()).thenReturn(xaDataSource);
Map result = new HashMap<>();
result.put(datasourceName, singleXADataSource);
return result;
}
private Collection createResourceDataSources(final Class dataSourceClass, final DatabaseType databaseType) {
List result = new LinkedList<>();
result.add(new ResourceDataSource("ds1", DataSourceUtils.build(dataSourceClass, databaseType, "demo_ds_1")));
result.add(new ResourceDataSource("ds2", DataSourceUtils.build(dataSourceClass, databaseType, "demo_ds_2")));
return result;
}
private Collection createAtomikosDataSourceBeanResource() {
List result = new LinkedList<>();
result.add(new ResourceDataSource("ds1", new AtomikosDataSourceBean()));
result.add(new ResourceDataSource("ds2", new AtomikosDataSourceBean()));
return result;
}
} - 这里mock了xaTransactionManager、transactionManager
小结
- XAShardingTransactionManager实现了ShardingTransactionManager接口，它拥有singleXADataSourceMap、xaTransactionManager、enlistedXAResource三个属性，其init方法对这三个属性进行了初始化
- getTransactionType方法返回的是TransactionType.XA；isInTransaction方法则依据xaTransactionManager.getTransactionManager().getStatus()来判断；getConnection方法从singleXADataSourceMap取出singleXAConnection，然后执行其getConnection方法
- begin方法执行的是xaTransactionManager.getTransactionManager().begin()；commit方法则调用了xaTransactionManager.getTransactionManager().commit()，其会在finally中执行enlistedXAResource.remove()；rollback方法调用了xaTransactionManager.getTransactionManager().rollback()，其也在finally中执行enlistedXAResource.remove()；close方法则执行xaTransactionManager.removeRecoveryResource、singleXADataSourceMap.clear()、xaTransactionManager.close()