org.kiji.hive.KijiTableInfo.java Source code

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Here is the source code for org.kiji.hive.KijiTableInfo.java

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/**
 * (c) Copyright 2013 WibiData, Inc.
 *
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * 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.kiji.hive;

import java.io.Closeable;
import java.io.IOException;
import java.util.Properties;

import org.apache.commons.io.IOUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;

import org.kiji.schema.Kiji;
import org.kiji.schema.KijiTable;
import org.kiji.schema.KijiURI;
import org.kiji.schema.impl.hbase.HBaseKijiTable;
import org.kiji.schema.layout.KijiTableLayout;
import org.kiji.schema.util.ResourceUtils;

/**
 * Contains all the information about a kiji table relevant to using hive.
 */
public class KijiTableInfo implements Closeable {
    public static final String KIJI_TABLE_URI = "kiji.table.uri";

    private final KijiURI mKijiURI;

    private Connection mConnection;

    /**
     * Constructor.
     *
     * @param properties The Hive table properties.
     */
    public KijiTableInfo(Properties properties) {
        mKijiURI = getURIFromProperties(properties);
        mConnection = null;
    }

    /**
     * Gets the URI from the passed in properties.
     * @param properties for the job.
     * @return KijiURI extracted from the passed in properties.
     */
    public static KijiURI getURIFromProperties(Properties properties) {
        String kijiURIString = properties.getProperty(KIJI_TABLE_URI);
        //TODO Pretty exceptions for URI parser issues.
        KijiURI kijiURI = KijiURI.newBuilder(kijiURIString).build();

        //TODO Ensure that this URI has a table component.
        return kijiURI;
    }

    /**
     * Gets the URI for this KijiTableInfo.
     *
     * @return KijiURI associated with this KijiTableInfo
     */
    public KijiURI getKijiTableURI() {
        return mKijiURI;
    }

    /**
     * Gets the Kiji table layout.
     *
     * @return The table layout.
     * @throws IOException If it cannot be read.
     */
    public KijiTableLayout getTableLayout() throws IOException {
        return getConnection().getTableLayout();
    }

    /** {@inheritDoc} */
    @Override
    public void close() throws IOException {
        IOUtils.closeQuietly(mConnection);
    }

    /**
     * Gets a connection to the Kiji table.
     *
     * @return A connection.
     * @throws IOException If the connection cannot be established.
     */
    private Connection getConnection() throws IOException {
        if (null == mConnection) {
            mConnection = new Connection(mKijiURI);
        }
        return mConnection;
    }

    /**
     * Connection to a Kiji table and its metadata.
     */
    private static class Connection implements Closeable {
        /** The Kiji connection. */
        private final Kiji mKiji;
        /** The Kiji table connection. */
        private final KijiTable mKijiTable;

        /**
         * Opens a connection.
         * @param kijiURI The kijiURI
         * @throws IOException If there is a connection error.
         */
        public Connection(KijiURI kijiURI) throws IOException {
            final Configuration conf = HBaseConfiguration.create();

            mKiji = Kiji.Factory.open(kijiURI);
            mKijiTable = mKiji.openTable(kijiURI.getTable());
        }

        /**
         * Gets the layout of the Kiji table.
         *
         * @return The table layout.
         */
        public KijiTableLayout getTableLayout() {
            return HBaseKijiTable.downcast(mKijiTable).getLayout();
        }

        /** {@inheritDoc} */
        @Override
        public void close() throws IOException {
            ResourceUtils.releaseOrLog(mKijiTable);
            ResourceUtils.releaseOrLog(mKiji);
        }
    }
}