com.pinterest.deployservice.db.DBUtilDAOImpl.java Source code

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Here is the source code for com.pinterest.deployservice.db.DBUtilDAOImpl.java

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/**
 * Copyright 2016 Pinterest, 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 com.pinterest.deployservice.db;

import com.pinterest.deployservice.dao.UtilDAO;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.sql.Connection;

public class DBUtilDAOImpl implements UtilDAO {
    private static final Logger LOG = LoggerFactory.getLogger(DBUtilDAOImpl.class);
    private static final String GET_LOCK_TEMPLATE = "SELECT GET_LOCK('%s', %d)";
    private static final String RELEASE_LOCK_TEMPLATE = "SELECT RELEASE_LOCK('%s')";
    // In sec, do not set it more then 10 sec, server will kill query takes more than 10 sec
    // Smaller timeout makes sense, we do not want server to be occupied by such requests
    // 0 means return immediately
    private static final int LOCK_TIMEOUT = 0;

    private BasicDataSource dataSource;

    public DBUtilDAOImpl(BasicDataSource dataSource) {
        this.dataSource = dataSource;
    }

    @Override
    public Connection getLock(String id) {
        Connection connection = null;
        try {
            connection = dataSource.getConnection();
            connection.setAutoCommit(false);
            long status = new QueryRunner().query(connection, String.format(GET_LOCK_TEMPLATE, id, LOCK_TIMEOUT),
                    SingleResultSetHandlerFactory.<Long>newObjectHandler());
            if (status == 1L) {
                return connection;
            }
        } catch (Exception e) {
            LOG.error("Failed to call getLock on id {}.", id, e);
        }
        DbUtils.closeQuietly(connection);
        return null;
    }

    @Override
    public void releaseLock(String id, Connection connection) {
        try {
            new QueryRunner().query(connection, String.format(RELEASE_LOCK_TEMPLATE, id),
                    SingleResultSetHandlerFactory.<Long>newObjectHandler());
        } catch (Exception e) {
            LOG.error("Failed to call releaseLock on id {}.", id, e);
        }
        DbUtils.closeQuietly(connection);
    }
}