/**
 * 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.regionserver.wal;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.io.util.Dictionary;
import org.apache.hadoop.hbase.io.util.LRUDictionary;
import org.apache.hadoop.hbase.testclassification.RegionServerTests;
import org.apache.hadoop.hbase.testclassification.SmallTests;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.BeforeClass;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.experimental.categories.Category;

/**
 * Test our compressor class.
 */
@Category({RegionServerTests.class, SmallTests.class})
public class TestCompressor {

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

  @BeforeClass
  public static void setUpBeforeClass() throws Exception {
  }

  @Test
  public void testToShort() {
    short s = 1;
    assertEquals(s, Compressor.toShort((byte)0, (byte)1));
    s <<= 8;
    assertEquals(s, Compressor.toShort((byte)1, (byte)0));
  }

  @Test (expected = IllegalArgumentException.class)
  public void testNegativeToShort() {
    Compressor.toShort((byte)0xff, (byte)0xff);
  }

  @Test
  public void testCompressingWithNullDictionaries() throws IOException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    DataOutputStream dos = new DataOutputStream(baos);
    byte [] blahBytes = Bytes.toBytes("blah");
    Compressor.writeCompressed(blahBytes, 0, blahBytes.length, dos, null);
    dos.close();
    byte [] dosbytes = baos.toByteArray();
    DataInputStream dis =
      new DataInputStream(new ByteArrayInputStream(dosbytes));
    byte [] product = Compressor.readCompressed(dis, null);
    assertTrue(Bytes.equals(blahBytes, product));
  }

  @Test
  public void testCompressingWithClearDictionaries() throws IOException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    DataOutputStream dos = new DataOutputStream(baos);
    Dictionary dictionary = new LRUDictionary();
    dictionary.init(Short.MAX_VALUE);
    byte [] blahBytes = Bytes.toBytes("blah");
    Compressor.writeCompressed(blahBytes, 0, blahBytes.length, dos, dictionary);
    dos.close();
    byte [] dosbytes = baos.toByteArray();
    DataInputStream dis =
      new DataInputStream(new ByteArrayInputStream(dosbytes));
    dictionary = new LRUDictionary();
    dictionary.init(Short.MAX_VALUE);
    byte [] product = Compressor.readCompressed(dis, dictionary);
    assertTrue(Bytes.equals(blahBytes, product));
  }
}
