/**
 * 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.io;

import java.io.IOException;

import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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

public class TestWritableUtils {
  private static final Logger LOG =
      LoggerFactory.getLogger(TestWritableUtils.class);

  private void testValue(int val, int vintlen) throws IOException {
    DataOutputBuffer buf = new DataOutputBuffer();
    DataInputBuffer inbuf = new DataInputBuffer();
    WritableUtils.writeVInt(buf, val);
    if (LOG.isDebugEnabled()) {
      LOG.debug("Value = " + val);
      BytesWritable printer = new BytesWritable();
      printer.set(buf.getData(), 0, buf.getLength());
      LOG.debug("Buffer = " + printer);
    }
    inbuf.reset(buf.getData(), 0, buf.getLength());
    assertEquals(val, WritableUtils.readVInt(inbuf));
    assertEquals(vintlen, buf.getLength());
    assertEquals(vintlen, WritableUtils.getVIntSize(val));
    assertEquals(vintlen, WritableUtils.decodeVIntSize(buf.getData()[0]));
  }
  private void testReadInRange(long val, int lower,
      int upper, boolean expectSuccess) throws IOException {
    DataOutputBuffer buf = new DataOutputBuffer();
    DataInputBuffer inbuf = new DataInputBuffer();
    WritableUtils.writeVLong(buf, val);
    try {
      inbuf.reset(buf.getData(), 0, buf.getLength());
      long val2 = WritableUtils.readVIntInRange(inbuf, lower, upper);
      if (!expectSuccess) {
        fail("expected readVIntInRange to throw an exception");
      }
      assertEquals(val, val2);
    } catch(IOException e) {
      if (expectSuccess) {
        LOG.error("unexpected exception:", e);
        fail("readVIntInRange threw an unexpected exception");
      }
    }
  }

  @Test
  public void testVInt() throws Exception {
    testValue(12, 1);
    testValue(127, 1);
    testValue(-112, 1);
    testValue(-113, 2);
    testValue(-128, 2);
    testValue(128, 2);
    testValue(-129, 2);
    testValue(255, 2);
    testValue(-256, 2);
    testValue(256, 3);
    testValue(-257, 3);
    testValue(65535, 3);
    testValue(-65536, 3);
    testValue(65536, 4);
    testValue(-65537, 4);
    testReadInRange(123, 122, 123, true);
    testReadInRange(123, 0, 100, false);
    testReadInRange(0, 0, 100, true);
    testReadInRange(-1, 0, 100, false);
    testReadInRange(1099511627776L, 0, Integer.MAX_VALUE, false);
  }
}