/**
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.hadoop.hbase.client;

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

import org.apache.hadoop.hbase.HRegionLocation;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.util.Pair;

/**
 * Used to view region location information for a single HBase table.
 * Obtain an instance from an {@link Connection}.
 *
 * @see ConnectionFactory
 * @see Connection
 * @see Table
 * @since 0.99.0
 */
@InterfaceAudience.Public
public interface RegionLocator extends Closeable {
  /**
   * Finds the region on which the given row is being served. Does not reload the cache.
   * @param row Row to find.
   * @return Location of the row.
   * @throws IOException if a remote or network exception occurs
   */
  public HRegionLocation getRegionLocation(final byte [] row) throws IOException;

  /**
   * Finds the region on which the given row is being served.
   * @param row Row to find.
   * @param reload true to reload information or false to use cached information
   * @return Location of the row.
   * @throws IOException if a remote or network exception occurs
   */
  public HRegionLocation getRegionLocation(final byte [] row, boolean reload)
    throws IOException;

  /**
   * Retrieves all of the regions associated with this table.
   * @return a {@link List} of all regions associated with this table.
   * @throws IOException if a remote or network exception occurs
   */
  public List<HRegionLocation> getAllRegionLocations()
    throws IOException;

  /**
   * Gets the starting row key for every region in the currently open table.
   * <p>
   * This is mainly useful for the MapReduce integration.
   * @return Array of region starting row keys
   * @throws IOException if a remote or network exception occurs
   */
  public byte [][] getStartKeys() throws IOException;

  /**
   * Gets the ending row key for every region in the currently open table.
   * <p>
   * This is mainly useful for the MapReduce integration.
   * @return Array of region ending row keys
   * @throws IOException if a remote or network exception occurs
   */
  public byte[][] getEndKeys() throws IOException;

  /**
   * Gets the starting and ending row keys for every region in the currently
   * open table.
   * <p>
   * This is mainly useful for the MapReduce integration.
   * @return Pair of arrays of region starting and ending row keys
   * @throws IOException if a remote or network exception occurs
   */
  public Pair<byte[][],byte[][]> getStartEndKeys() throws IOException;

  /**
   * Gets the fully qualified table name instance of this table.
   */
  TableName getName();
}