com.vmware.photon.controller.api.common.db.TransactionalInterceptor.java Source code

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Here is the source code for com.vmware.photon.controller.api.common.db.TransactionalInterceptor.java

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/*
 * Copyright 2015 VMware, Inc. All Rights Reserved.
 *
 * 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 com.vmware.photon.controller.api.common.db;

import com.vmware.photon.controller.common.metrics.DefaultMetricRegistry;

import com.codahale.metrics.Meter;
import com.codahale.metrics.Timer;
import com.google.common.base.Stopwatch;
import com.google.inject.Inject;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.context.internal.ManagedSessionContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static com.codahale.metrics.MetricRegistry.name;

import javax.inject.Provider;

import java.util.concurrent.TimeUnit;

/**
 * Intercepts calls to methods marked by {@link Transactional} and wraps them with a Hibernate transaction.
 */
public class TransactionalInterceptor implements MethodInterceptor {

    private static final Logger logger = LoggerFactory.getLogger(TransactionalInterceptor.class);

    private final Timer transactions;

    private final Meter transactionExceptions;

    @Inject
    private Provider<SessionFactory> sessionFactoryProvider;

    public TransactionalInterceptor() {
        transactions = DefaultMetricRegistry.REGISTRY.timer(name(TransactionalInterceptor.class, "transactions"));
        transactionExceptions = DefaultMetricRegistry.REGISTRY
                .meter(name(TransactionalInterceptor.class, "transaction-exceptions"));
    }

    @Override
    public Object invoke(MethodInvocation invocation) throws Throwable {
        SessionFactory sessionFactory = sessionFactoryProvider.get();

        Session session;
        if (ManagedSessionContext.hasBind(sessionFactory)) {
            session = sessionFactory.getCurrentSession();
        } else {
            session = sessionFactory.openSession();
            ManagedSessionContext.bind(session);
        }

        Transaction transaction = session.getTransaction();
        if (transaction.isActive()) {
            return invocation.proceed();
        }

        Stopwatch stopwatch = Stopwatch.createUnstarted();

        try {
            logger.trace("beginning transaction: {}", transaction);
            stopwatch.start();
            transaction.begin();
            Object result = invocation.proceed();
            transaction.commit();
            stopwatch.stop();
            logger.debug("committed: {}", transaction);
            return result;
        } catch (Throwable t) {
            logger.debug("rolling back: {}", transaction, t);
            transaction.rollback();
            transactionExceptions.mark();
            throw t;
        } finally {
            final long elapsedTime = stopwatch.elapsed(TimeUnit.MILLISECONDS);
            transactions.update(elapsedTime, TimeUnit.MILLISECONDS);
            ManagedSessionContext.unbind(sessionFactory);
            if (session.isOpen()) {
                session.close();
            }
            final long transactionTimeWarningThresholdInMilliseconds = 2000L;
            if (elapsedTime > transactionTimeWarningThresholdInMilliseconds) {
                logger.warn("Transaction {} took {} milliseconds", transaction, elapsedTime);
            }
        }
    }
}