com.bah.culvert.accumulo.database.AccumuloDatabaseAdapter.java Source code

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Here is the source code for com.bah.culvert.accumulo.database.AccumuloDatabaseAdapter.java

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/**
 * Copyright 2011 Booz Allen Hamilton.
 * 
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership. Booz Allen Hamilton
 * 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
 *
 *     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.bah.culvert.accumulo.database;

import static com.bah.culvert.accumulo.AccumuloConstants.DEFAULT_MAX_LATENCY;
import static com.bah.culvert.accumulo.AccumuloConstants.DEFAULT_MAX_MEMORY;
import static com.bah.culvert.accumulo.AccumuloConstants.DEFAULT_MAX_THREADS;
import static com.bah.culvert.accumulo.AccumuloConstants.MAX_LATENCY_KEY;
import static com.bah.culvert.accumulo.AccumuloConstants.MAX_MEMORY_KEY;
import static com.bah.culvert.accumulo.AccumuloConstants.MAX_THREADS_KEY;

import java.util.List;
import java.util.SortedSet;
import java.util.TreeSet;

import org.apache.accumulo.core.client.Connector;
import org.apache.accumulo.core.client.Instance;
import org.apache.accumulo.core.client.ZooKeeperInstance;
import org.apache.accumulo.core.client.mock.MockInstance;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Text;

import com.bah.culvert.accumulo.AccumuloConstants;
import com.bah.culvert.adapter.DatabaseAdapter;
import com.bah.culvert.adapter.TableAdapter;
import com.bah.culvert.data.CColumn;
import com.bah.culvert.util.Exceptions;

/**
 * Adapter for connecting to an Accumulo instance.
 */
public class AccumuloDatabaseAdapter extends DatabaseAdapter {

    private static final Log LOG = LogFactory.getLog(AccumuloDatabaseAdapter.class);

    private Connector conn;
    private Instance inst;

    /**
     * Overloading the use of this method to actually create the connection
     */
    @Override
    public boolean verify() {
        Configuration conf = this.getConf();
        try {
            this.inst = getInstance(conf);
            this.conn = inst.getConnector(conf.get(AccumuloConstants.USERNAME_KEY),
                    conf.get(AccumuloConstants.PASSWORD_KEY));
        } catch (Exception e) {
            throw new RuntimeException("Could not verify/create connection to Accumulo", e);
        }
        return true;
    }

    private static Instance getInstance(Configuration conf) throws ClassNotFoundException {
        String instClass = conf.get(AccumuloConstants.INSTANCE_CLASS_KEY);
        Class<? extends Instance> clazz;

        // make sure that we have a valid instance
        if (instClass == null) {
            LOG.debug("No instance type specified for connecting to Accumulo, using default");
            clazz = AccumuloConstants.DEFAULT_INSTANCE_CLASS;
        } else
            clazz = Class.forName(instClass).asSubclass(Instance.class);

        // create the valid instance
        if (clazz.equals(ZooKeeperInstance.class))
            return new ZooKeeperInstance(conf.get(AccumuloConstants.INSTANCE_NAME_KEY),
                    conf.get(AccumuloConstants.ZOOKEEPER_SERVERS_KEY));
        else if (clazz.equals(MockInstance.class))
            return new MockInstance(
                    conf.get(AccumuloConstants.INSTANCE_NAME_KEY, AccumuloConstants.DEFAULT_INSTANCE_NAME));
        else
            throw new IllegalArgumentException(instClass + "is not a valid instance class");
    }

    @Override
    public TableAdapter getTableAdapter(String tableName) {
        Configuration conf = this.getConf();
        return new AccumuloTableAdapter(this.conn, tableName, conf.getLong(MAX_MEMORY_KEY, DEFAULT_MAX_MEMORY),
                conf.getLong(MAX_LATENCY_KEY, DEFAULT_MAX_LATENCY),
                conf.getInt(MAX_THREADS_KEY, DEFAULT_MAX_THREADS));
    }

    @Override
    public void create(String tableName, byte[][] splitKeys, List<CColumn> columns) {
        try {
            this.conn.tableOperations().create(tableName);
            // copy over the split keys into a format that accumulo can understand
            SortedSet<Text> partitionKeys = new TreeSet<Text>();
            for (byte[] split : splitKeys)
                partitionKeys.add(new Text(split));
            // and add the splits
            this.conn.tableOperations().addSplits(tableName, partitionKeys);
        } catch (Exception e) {
            throw Exceptions.asRuntime(e);
        }

    }

    @Override
    public void delete(String tableName) {
        try {
            if (this.conn.tableOperations().exists(tableName))
                this.conn.tableOperations().delete(tableName);
        } catch (Exception e) {
            throw Exceptions.asRuntime(e);
        }

    }

    @Override
    public boolean tableExists(String tableName) {
        return this.conn.tableOperations().exists(tableName);
    }

}