hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestLimitedScanWithFilter.java

/**
 * 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 static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;

import java.io.IOException;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.HBaseTestingUtility;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.testclassification.ClientTests;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.experimental.categories.Category;

/**
 * With filter we may stop at a middle of row and think that we still have more cells for the
 * current row but actually all the remaining cells will be filtered out by the filter. So it will
 * lead to a Result that mayHaveMoreCellsInRow is true but actually there are no cells for the same
 * row. Here we want to test if our limited scan still works.
 */
@Category({ MediumTests.class, ClientTests.class })
public class TestLimitedScanWithFilter {

  @ClassRule
  public static final HBaseClassTestRule CLASS_RULE =
      HBaseClassTestRule.forClass(TestLimitedScanWithFilter.class);

  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();

  private static final TableName TABLE_NAME = TableName.valueOf("TestRegionScanner");

  private static final byte[] FAMILY = Bytes.toBytes("cf");

  private static final byte[][] CQS =
      { Bytes.toBytes("cq1"), Bytes.toBytes("cq2"), Bytes.toBytes("cq3"), Bytes.toBytes("cq4") };

  private static int ROW_COUNT = 10;

  @BeforeClass
  public static void setUp() throws Exception {
    UTIL.startMiniCluster(1);
    try (Table table = UTIL.createTable(TABLE_NAME, FAMILY)) {
      for (int i = 0; i < ROW_COUNT; i++) {
        Put put = new Put(Bytes.toBytes(i));
        for (int j = 0; j < CQS.length; j++) {
          put.addColumn(FAMILY, CQS[j], Bytes.toBytes((j + 1) * i));
        }
        table.put(put);
      }
    }
  }

  @AfterClass
  public static void tearDown() throws Exception {
    UTIL.shutdownMiniCluster();
  }

  @Test
  public void testCompleteResult() throws IOException {
    int limit = 5;
    Scan scan =
        new Scan().setFilter(new ColumnCountOnRowFilter(2)).setMaxResultSize(1).setLimit(limit);
    try (Table table = UTIL.getConnection().getTable(TABLE_NAME);
        ResultScanner scanner = table.getScanner(scan)) {
      for (int i = 0; i < limit; i++) {
        Result result = scanner.next();
        assertEquals(i, Bytes.toInt(result.getRow()));
        assertEquals(2, result.size());
        assertFalse(result.mayHaveMoreCellsInRow());
        assertEquals(i, Bytes.toInt(result.getValue(FAMILY, CQS[0])));
        assertEquals(2 * i, Bytes.toInt(result.getValue(FAMILY, CQS[1])));
      }
      assertNull(scanner.next());
    }
  }

  @Test
  public void testAllowPartial() throws IOException {
    int limit = 5;
    Scan scan = new Scan().setFilter(new ColumnCountOnRowFilter(2)).setMaxResultSize(1)
        .setAllowPartialResults(true).setLimit(limit);
    try (Table table = UTIL.getConnection().getTable(TABLE_NAME);
        ResultScanner scanner = table.getScanner(scan)) {
      for (int i = 0; i < 2 * limit; i++) {
        int key = i / 2;
        Result result = scanner.next();
        assertEquals(key, Bytes.toInt(result.getRow()));
        assertEquals(1, result.size());
        assertTrue(result.mayHaveMoreCellsInRow());
        int cqIndex = i % 2;
        assertEquals(key * (cqIndex + 1), Bytes.toInt(result.getValue(FAMILY, CQS[cqIndex])));
      }
      assertNull(scanner.next());
    }
  }

  @Test
  public void testBatchAllowPartial() throws IOException {
    int limit = 5;
    Scan scan = new Scan().setFilter(new ColumnCountOnRowFilter(3)).setBatch(2).setMaxResultSize(1)
        .setAllowPartialResults(true).setLimit(limit);
    try (Table table = UTIL.getConnection().getTable(TABLE_NAME);
        ResultScanner scanner = table.getScanner(scan)) {
      for (int i = 0; i < 3 * limit; i++) {
        int key = i / 3;
        Result result = scanner.next();
        assertEquals(key, Bytes.toInt(result.getRow()));
        assertEquals(1, result.size());
        assertTrue(result.mayHaveMoreCellsInRow());
        int cqIndex = i % 3;
        assertEquals(key * (cqIndex + 1), Bytes.toInt(result.getValue(FAMILY, CQS[cqIndex])));
      }
      assertNull(scanner.next());
    }
  }

  @Test
  public void testBatch() throws IOException {
    int limit = 5;
    Scan scan = new Scan().setFilter(new ColumnCountOnRowFilter(2)).setBatch(2).setMaxResultSize(1)
        .setLimit(limit);
    try (Table table = UTIL.getConnection().getTable(TABLE_NAME);
        ResultScanner scanner = table.getScanner(scan)) {
      for (int i = 0; i < limit; i++) {
        Result result = scanner.next();
        assertEquals(i, Bytes.toInt(result.getRow()));
        assertEquals(2, result.size());
        assertTrue(result.mayHaveMoreCellsInRow());
        assertEquals(i, Bytes.toInt(result.getValue(FAMILY, CQS[0])));
        assertEquals(2 * i, Bytes.toInt(result.getValue(FAMILY, CQS[1])));
      }
      assertNull(scanner.next());
    }
  }

  @Test
  public void testBatchAndFilterDiffer() throws IOException {
    int limit = 5;
    Scan scan = new Scan().setFilter(new ColumnCountOnRowFilter(3)).setBatch(2).setMaxResultSize(1)
        .setLimit(limit);
    try (Table table = UTIL.getConnection().getTable(TABLE_NAME);
        ResultScanner scanner = table.getScanner(scan)) {
      for (int i = 0; i < limit; i++) {
        Result result = scanner.next();
        assertEquals(i, Bytes.toInt(result.getRow()));
        assertEquals(2, result.size());
        assertTrue(result.mayHaveMoreCellsInRow());
        assertEquals(i, Bytes.toInt(result.getValue(FAMILY, CQS[0])));
        assertEquals(2 * i, Bytes.toInt(result.getValue(FAMILY, CQS[1])));
        result = scanner.next();
        assertEquals(i, Bytes.toInt(result.getRow()));
        assertEquals(1, result.size());
        assertFalse(result.mayHaveMoreCellsInRow());
        assertEquals(3 * i, Bytes.toInt(result.getValue(FAMILY, CQS[2])));
      }
      assertNull(scanner.next());
    }
  }
}