/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.tomcat.dbcp.dbcp2.managed;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Map;
import java.util.Objects;
import java.util.WeakHashMap;
import javax.transaction.xa.XAResource;
import jakarta.transaction.SystemException;
import jakarta.transaction.Transaction;
import jakarta.transaction.TransactionManager;
import jakarta.transaction.TransactionSynchronizationRegistry;
import org.apache.tomcat.dbcp.dbcp2.DelegatingConnection;
/**
* TransactionRegistry tracks Connections and XAResources in a transacted environment for a single XAConnectionFactory.
* <p>
* The TransactionRegistry hides the details of transaction processing from the existing DBCP pooling code, and gives
* the ManagedConnection a way to enlist connections in a transaction, allowing for the maximal rescue of DBCP.
* </p>
*
* @since 2.0
*/
public class TransactionRegistry {
private final TransactionManager transactionManager;
private final Map<Transaction, TransactionContext> caches = new WeakHashMap<>();
private final Map<Connection, XAResource> xaResources = new WeakHashMap<>();
private final TransactionSynchronizationRegistry transactionSynchronizationRegistry;
/**
* Provided for backwards compatibility
* @param transactionManager the transaction manager used to enlist connections
*/
public TransactionRegistry(final TransactionManager transactionManager) {
this (transactionManager, null);
}
/**
* Creates a TransactionRegistry for the specified transaction manager.
*
* @param transactionManager
* the transaction manager used to enlist connections.
* @param transactionSynchronizationRegistry
* The optional TSR to register synchronizations with
* @since 2.6.0
*/
public TransactionRegistry(final TransactionManager transactionManager, final TransactionSynchronizationRegistry transactionSynchronizationRegistry) {
this.transactionManager = transactionManager;
this.transactionSynchronizationRegistry = transactionSynchronizationRegistry;
}
/**
* Gets the active TransactionContext or null if not Transaction is active.
*
* @return The active TransactionContext or null if no Transaction is active.
* @throws SQLException
* Thrown when an error occurs while fetching the transaction.
*/
public TransactionContext getActiveTransactionContext() throws SQLException {
Transaction transaction = null;
try {
transaction = transactionManager.getTransaction();
// was there a transaction?
if (transaction == null) {
return null;
}
// This is the transaction on the thread so no need to check its status - we should try to use it and
// fail later based on the subsequent status
} catch (final SystemException e) {
throw new SQLException("Unable to determine current transaction ", e);
}
// register the context (or create a new one)
synchronized (this) {
return caches.computeIfAbsent(transaction, k -> new TransactionContext(this, k, transactionSynchronizationRegistry));
}
}
private Connection getConnectionKey(final Connection connection) {
final Connection result;
if (connection instanceof DelegatingConnection) {
result = ((DelegatingConnection<?>) connection).getInnermostDelegateInternal();
} else {
result = connection;
}
return result;
}
/**
* Gets the XAResource registered for the connection.
*
* @param connection
* the connection
* @return The XAResource registered for the connection; never null.
* @throws SQLException
* Thrown when the connection does not have a registered XAResource.
*/
public synchronized XAResource getXAResource(final Connection connection) throws SQLException {
Objects.requireNonNull(connection, "connection");
final Connection key = getConnectionKey(connection);
final XAResource xaResource = xaResources.get(key);
if (xaResource == null) {
throw new SQLException("Connection does not have a registered XAResource " + connection);
}
return xaResource;
}
/**
* Registers the association between a Connection and a XAResource. When a connection is enlisted in a transaction,
* it is actually the XAResource that is given to the transaction manager.
*
* @param connection
* The JDBC connection.
* @param xaResource
* The XAResource which managed the connection within a transaction.
*/
public synchronized void registerConnection(final Connection connection, final XAResource xaResource) {
Objects.requireNonNull(connection, "connection");
Objects.requireNonNull(xaResource, "xaResource");
xaResources.put(connection, xaResource);
}
/**
* Unregisters a destroyed connection from {@link TransactionRegistry}.
*
* @param connection
* A destroyed connection from {@link TransactionRegistry}.
*/
public synchronized void unregisterConnection(final Connection connection) {
xaResources.remove(getConnectionKey(connection));
}
}