co.cask.cdap.data2.transaction.Transactions.java Source code

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Here is the source code for co.cask.cdap.data2.transaction.Transactions.java

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/*
 * Copyright  2014-2015 Cask Data, Inc.
 *
 * 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 co.cask.cdap.data2.transaction;

import co.cask.tephra.Transaction;
import co.cask.tephra.TransactionAware;
import co.cask.tephra.TransactionContext;
import co.cask.tephra.TransactionExecutor;
import co.cask.tephra.TransactionExecutorFactory;
import co.cask.tephra.TransactionFailureException;
import co.cask.tephra.TransactionSystemClient;
import com.google.common.base.Functions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.Callable;

/**
 * Helper class for interacting with {@link Transaction} and {@link TransactionSystemClient}.
 */
public final class Transactions {

    private static final Logger LOG = LoggerFactory.getLogger(Transactions.class);

    public static void abortQuietly(TransactionSystemClient txClient, Transaction tx) {
        try {
            txClient.abort(tx);
        } catch (Throwable t) {
            LOG.error("Exception when aborting transaction {}", tx, t);
        }
    }

    public static void invalidateQuietly(TransactionSystemClient txClient, Transaction tx) {
        try {
            txClient.invalidate(tx.getWritePointer());
        } catch (Throwable t) {
            LOG.error("Exception when invalidating transaction {}", tx, t);
        }
    }

    /**
     * Handy method to create {@link TransactionExecutor} (See TEPHRA-71).
     */
    public static TransactionExecutor createTransactionExecutor(TransactionExecutorFactory factory,
            Iterable<? extends TransactionAware> txAwares) {
        return factory.createExecutor(Iterables.transform(txAwares, Functions.<TransactionAware>identity()));
    }

    /**
     * Handy method to create {@link TransactionExecutor} with single {@link TransactionAware}.
     */
    public static TransactionExecutor createTransactionExecutor(TransactionExecutorFactory factory,
            TransactionAware txAware) {
        return factory.createExecutor(ImmutableList.of(txAware));
    }

    /**
     * Executes the given {@link Runnable} in a short transaction using the given {@link TransactionContext}.
     *
     * @param txContext the {@link TransactionContext} for managing the transaction lifecycle
     * @param name descriptive name for the runnable
     * @param runnable the Runnable to be executed inside a transaction
     * @throws TransactionFailureException if failed to execute in a transaction. The cause of the exception carries the
     *                                     reason of failure.
     */
    public static void execute(TransactionContext txContext, String name, final Runnable runnable)
            throws TransactionFailureException {
        execute(txContext, name, new Callable<Void>() {
            @Override
            public Void call() throws Exception {
                runnable.run();
                return null;
            }
        });
    }

    /**
     * Executes the given {@link Callable} in a short transaction using the given {@link TransactionContext}.
     *
     * @param txContext the {@link TransactionContext} for managing the transaction lifecycle
     * @param name descriptive name for the runnable
     * @param callable the Callable to be executed inside a transaction
     * @return the result returned by {@link Callable#call()}
     * @throws TransactionFailureException if failed to execute in a transaction. The cause of the exception carries the
     *                                     reason of failure.
     */
    public static <V> V execute(TransactionContext txContext, String name, Callable<V> callable)
            throws TransactionFailureException {
        V result = null;
        txContext.start();
        try {
            result = callable.call();
        } catch (Throwable t) {
            // Abort will always throw with the TransactionFailureException.
            txContext.abort(new TransactionFailureException(
                    "Failed to execute method " + name + "inside a transaction", t));
        }

        // If commit failed, the tx will be aborted and exception will be raised
        txContext.finish();
        return result;
    }

    private Transactions() {
        // Private the constructor for util class
    }
}