flink-filesystems/flink-hadoop-fs/src/test/java/org/apache/flink/runtime/fs/hdfs/HadoopDataInputStreamTest.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.flink.runtime.fs.hdfs;

import org.apache.flink.core.memory.ByteArrayInputStreamWithPos;

import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.PositionedReadable;
import org.apache.hadoop.fs.Seekable;
import org.junit.Assert;
import org.junit.Test;

import java.io.IOException;

import static org.mockito.Matchers.anyLong;
import static org.mockito.Mockito.atLeastOnce;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.reset;
import static org.mockito.Mockito.spy;
import static org.mockito.Mockito.verify;

/**
 * Tests for the {@link HadoopDataInputStream}.
 */
public class HadoopDataInputStreamTest {

	private FSDataInputStream verifyInputStream;
	private HadoopDataInputStream testInputStream;

	@Test
	public void testSeekSkip() throws IOException {
		verifyInputStream = spy(new FSDataInputStream(new SeekableByteArrayInputStream(new byte[2 * HadoopDataInputStream.MIN_SKIP_BYTES])));
		testInputStream = new HadoopDataInputStream(verifyInputStream);
		seekAndAssert(10);
		seekAndAssert(10 + HadoopDataInputStream.MIN_SKIP_BYTES + 1);
		seekAndAssert(testInputStream.getPos() - 1);
		seekAndAssert(testInputStream.getPos() + 1);
		seekAndAssert(testInputStream.getPos() - HadoopDataInputStream.MIN_SKIP_BYTES);
		seekAndAssert(testInputStream.getPos());
		seekAndAssert(0);
		seekAndAssert(testInputStream.getPos() + HadoopDataInputStream.MIN_SKIP_BYTES);
		seekAndAssert(testInputStream.getPos() + HadoopDataInputStream.MIN_SKIP_BYTES - 1);

		try {
			seekAndAssert(-1);
			Assert.fail();
		} catch (Exception ignore) {
		}

		try {
			seekAndAssert(-HadoopDataInputStream.MIN_SKIP_BYTES - 1);
			Assert.fail();
		} catch (Exception ignore) {
		}
	}

	private void seekAndAssert(long seekPos) throws IOException {
		Assert.assertEquals(verifyInputStream.getPos(), testInputStream.getPos());
		long delta = seekPos - testInputStream.getPos();
		testInputStream.seek(seekPos);

		if (delta > 0L && delta <= HadoopDataInputStream.MIN_SKIP_BYTES) {
			verify(verifyInputStream, atLeastOnce()).skip(anyLong());
			verify(verifyInputStream, never()).seek(anyLong());
		} else if (delta != 0L) {
			verify(verifyInputStream, atLeastOnce()).seek(seekPos);
			verify(verifyInputStream, never()).skip(anyLong());
		} else {
			verify(verifyInputStream, never()).seek(anyLong());
			verify(verifyInputStream, never()).skip(anyLong());
		}

		Assert.assertEquals(seekPos, verifyInputStream.getPos());
		reset(verifyInputStream);
	}

	private static final class SeekableByteArrayInputStream
		extends ByteArrayInputStreamWithPos
		implements Seekable, PositionedReadable {

		public SeekableByteArrayInputStream(byte[] buffer) {
			super(buffer);
		}

		@Override
		public void seek(long pos) throws IOException {
			setPosition((int) pos);
		}

		@Override
		public long getPos() throws IOException {
			return getPosition();
		}

		@Override
		public boolean seekToNewSource(long targetPos) throws IOException {
			return false;
		}

		@Override
		public int read(long position, byte[] buffer, int offset, int length) throws IOException {
			throw new UnsupportedOperationException();
		}

		@Override
		public void readFully(long position, byte[] buffer, int offset, int length) throws IOException {
			throw new UnsupportedOperationException();
		}

		@Override
		public void readFully(long position, byte[] buffer) throws IOException {
			throw new UnsupportedOperationException();
		}
	}
}