/*
* Copyright 2011-2014 the original author or authors.
*
* Licensed 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
*
* http://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.springframework.data.redis.core;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.cglib.proxy.MethodProxy;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.transaction.support.ResourceHolder;
import org.springframework.transaction.support.TransactionSynchronization;
import org.springframework.transaction.support.TransactionSynchronizationAdapter;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.util.Assert;
/**
* Helper class featuring {@link RedisConnection} handling, allowing for reuse of instances within
* 'transactions'/scopes.
*
* @author Costin Leau
* @author Christoph Strobl
* @author Thomas Darimont
*/
public abstract class RedisConnectionUtils {
private static final Log log = LogFactory.getLog(RedisConnectionUtils.class);
/**
* Binds a new Redis connection (from the given factory) to the current thread, if none is already bound.
*
* @param factory connection factory
* @return a new Redis connection without transaction support.
*/
public static RedisConnection bindConnection(RedisConnectionFactory factory) {
return bindConnection(factory, false);
}
/**
* Binds a new Redis connection (from the given factory) to the current thread, if none is already bound and enables
* transaction support if {@code enableTranactionSupport} is set to {@literal true}.
*
* @param factory connection factory
* @param enableTranactionSupport
* @return a new Redis connection with transaction support if requested.
*/
public static RedisConnection bindConnection(RedisConnectionFactory factory, boolean enableTranactionSupport) {
return doGetConnection(factory, true, true, enableTranactionSupport);
}
/**
* Gets a Redis connection from the given factory. Is aware of and will return any existing corresponding connections
* bound to the current thread, for example when using a transaction manager. Will always create a new connection
* otherwise.
*
* @param factory connection factory for creating the connection
* @return an active Redis connection without transaction management.
*/
public static RedisConnection getConnection(RedisConnectionFactory factory) {
return getConnection(factory, false);
}
/**
* Gets a Redis connection from the given factory. Is aware of and will return any existing corresponding connections
* bound to the current thread, for example when using a transaction manager. Will always create a new connection
* otherwise.
*
* @param factory connection factory for creating the connection
* @param enableTranactionSupport
* @return an active Redis connection with transaction management if requested.
*/
public static RedisConnection getConnection(RedisConnectionFactory factory, boolean enableTranactionSupport) {
return doGetConnection(factory, true, false, enableTranactionSupport);
}
/**
* Gets a Redis connection. Is aware of and will return any existing corresponding connections bound to the current
* thread, for example when using a transaction manager. Will create a new Connection otherwise, if
* {@code allowCreate} is <tt>true</tt>.
*
* @param factory connection factory for creating the connection
* @param allowCreate whether a new (unbound) connection should be created when no connection can be found for the
* current thread
* @param bind binds the connection to the thread, in case one was created
* @param enableTransactionSupport
* @return an active Redis connection
*/
public static RedisConnection doGetConnection(RedisConnectionFactory factory, boolean allowCreate, boolean bind,
boolean enableTransactionSupport) {
Assert.notNull(factory, "No RedisConnectionFactory specified");
RedisConnectionHolder connHolder = (RedisConnectionHolder) TransactionSynchronizationManager.getResource(factory);
if (connHolder != null) {
if (enableTransactionSupport) {
potentiallyRegisterTransactionSynchronisation(connHolder, factory);
}
return connHolder.getConnection();
}
if (!allowCreate) {
throw new IllegalArgumentException("No connection found and allowCreate = false");
}
if (log.isDebugEnabled()) {
log.debug("Opening RedisConnection");
}
RedisConnection conn = factory.getConnection();
if (bind) {
RedisConnection connectionToBind = conn;
if (enableTransactionSupport && isActualNonReadonlyTransactionActive()) {
connectionToBind = createConnectionProxy(conn, factory);
}
connHolder = new RedisConnectionHolder(connectionToBind);
TransactionSynchronizationManager.bindResource(factory, connHolder);
if (enableTransactionSupport) {
potentiallyRegisterTransactionSynchronisation(connHolder, factory);
}
return connHolder.getConnection();
}
return conn;
}
private static void potentiallyRegisterTransactionSynchronisation(RedisConnectionHolder connHolder,
final RedisConnectionFactory factory) {
if (isActualNonReadonlyTransactionActive()) {
if (!connHolder.isTransactionSyncronisationActive()) {
connHolder.setTransactionSyncronisationActive(true);
RedisConnection conn = connHolder.getConnection();
conn.multi();
TransactionSynchronizationManager.registerSynchronization(new RedisTransactionSynchronizer(connHolder, conn));
}
}
}
private static boolean isActualNonReadonlyTransactionActive() {
return TransactionSynchronizationManager.isActualTransactionActive()
&& !TransactionSynchronizationManager.isCurrentTransactionReadOnly();
}
private static RedisConnection createConnectionProxy(RedisConnection connection, RedisConnectionFactory factory) {
ProxyFactory proxyFactory = new ProxyFactory(connection);
proxyFactory.addAdvice(new ConnectionSplittingInterceptor(factory));
return RedisConnection.class.cast(proxyFactory.getProxy());
}
/**
* Closes the given connection, created via the given factory if not managed externally (i.e. not bound to the
* thread).
*
* @param conn the Redis connection to close
* @param factory the Redis factory that the connection was created with
*/
public static void releaseConnection(RedisConnection conn, RedisConnectionFactory factory) {
if (conn == null) {
return;
}
RedisConnectionHolder connHolder = (RedisConnectionHolder) TransactionSynchronizationManager.getResource(factory);
if (connHolder != null && connHolder.isTransactionSyncronisationActive()) {
if (log.isDebugEnabled()) {
log.debug("Redis Connection will be closed when transaction finished.");
}
return;
}
// Only release non-transactional/non-bound connections.
if (!isConnectionTransactional(conn, factory)) {
if (log.isDebugEnabled()) {
log.debug("Closing Redis Connection");
}
conn.close();
}
}
/**
* Unbinds and closes the connection (if any) associated with the given factory.
*
* @param factory Redis factory
*/
public static void unbindConnection(RedisConnectionFactory factory) {
RedisConnectionHolder connHolder = (RedisConnectionHolder) TransactionSynchronizationManager
.unbindResourceIfPossible(factory);
if (connHolder != null) {
if (connHolder.isTransactionSyncronisationActive()) {
if (log.isDebugEnabled()) {
log.debug("Redis Connection will be closed when outer transaction finished.");
}
} else {
if (log.isDebugEnabled()) {
log.debug("Closing bound connection.");
}
RedisConnection connection = connHolder.getConnection();
connection.close();
}
}
}
/**
* Return whether the given Redis connection is transactional, that is, bound to the current thread by Spring's
* transaction facilities.
*
* @param conn Redis connection to check
* @param connFactory Redis connection factory that the connection was created with
* @return whether the connection is transactional or not
*/
public static boolean isConnectionTransactional(RedisConnection conn, RedisConnectionFactory connFactory) {
if (connFactory == null) {
return false;
}
RedisConnectionHolder connHolder = (RedisConnectionHolder) TransactionSynchronizationManager
.getResource(connFactory);
return (connHolder != null && conn == connHolder.getConnection());
}
/**
* A {@link TransactionSynchronizationAdapter} that makes sure that the associated RedisConnection is released after the transaction completes.
*
* @author Christoph Strobl
* @author Thomas Darimont
*/
private static class RedisTransactionSynchronizer extends TransactionSynchronizationAdapter {
private final RedisConnectionHolder connHolder;
private final RedisConnection connection;
/**
* Creates a new {@link RedisTransactionSynchronizer}.
*
* @param connHolder
* @param connection
*/
private RedisTransactionSynchronizer(RedisConnectionHolder connHolder, RedisConnection connection) {
this.connHolder = connHolder;
this.connection = connection;
}
@Override
public void afterCompletion(int status) {
try {
switch (status) {
case TransactionSynchronization.STATUS_COMMITTED:
connection.exec();
break;
case TransactionSynchronization.STATUS_ROLLED_BACK:
case TransactionSynchronization.STATUS_UNKNOWN:
default:
connection.discard();
}
} finally {
if (log.isDebugEnabled()) {
log.debug("Closing bound connection after transaction completed with " + status);
}
connHolder.setTransactionSyncronisationActive(false);
connection.close();
}
}
}
/**
* @author Christoph Strobl
* @since 1.3
*/
static class ConnectionSplittingInterceptor implements MethodInterceptor,
org.springframework.cglib.proxy.MethodInterceptor {
private final RedisConnectionFactory factory;
public ConnectionSplittingInterceptor(RedisConnectionFactory factory) {
this.factory = factory;
}
@Override
public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
RedisCommand commandToExecute = RedisCommand.failsafeCommandLookup(method.getName());
if (isPotentiallyThreadBoundCommand(commandToExecute)) {
if (log.isDebugEnabled()) {
log.debug(String.format("Invoke '%s' on bound conneciton", method.getName()));
}
return invoke(method, obj, args);
}
if (log.isDebugEnabled()) {
log.debug(String.format("Invoke '%s' on unbound conneciton", method.getName()));
}
RedisConnection connection = factory.getConnection();
try {
return invoke(method, connection, args);
} finally {
// properly close the unbound connection after executing command
if (!connection.isClosed()) {
connection.close();
}
}
}
private Object invoke(Method method, Object target, Object[] args) throws Throwable {
try {
return method.invoke(target, args);
} catch (InvocationTargetException e) {
throw e.getCause();
}
}
@Override
public Object invoke(MethodInvocation invocation) throws Throwable {
return intercept(invocation.getThis(), invocation.getMethod(), invocation.getArguments(), null);
}
private boolean isPotentiallyThreadBoundCommand(RedisCommand command) {
return RedisCommand.UNKNOWN.equals(command) || !command.isReadonly();
}
}
/**
* @author Christoph Strobl
*/
private static class RedisConnectionHolder implements ResourceHolder {
private boolean unbound;
private final RedisConnection conn;
private boolean transactionSyncronisationActive;
public RedisConnectionHolder(RedisConnection conn) {
this.conn = conn;
}
public boolean isVoid() {
return unbound;
}
public RedisConnection getConnection() {
return conn;
}
public void reset() {
// no-op
}
public void unbound() {
this.unbound = true;
}
/**
* @return
* @since 1.3
*/
public boolean isTransactionSyncronisationActive() {
return transactionSyncronisationActive;
}
/**
* @param transactionSyncronisationActive
* @since 1.3
*/
public void setTransactionSyncronisationActive(boolean transactionSyncronisationActive) {
this.transactionSyncronisationActive = transactionSyncronisationActive;
}
}
}