/*
 * 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.io.network.netty;

import org.junit.Test;

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

/**
 * Tests for the {@link io.netty.buffer.PooledByteBufAllocator} wrapper.
 */
public class NettyBufferPoolTest {

	@Test
	public void testNoHeapAllocations() throws Exception {
		NettyBufferPool nettyBufferPool = new NettyBufferPool(1);

		// Buffers should prefer to be direct
		assertTrue(nettyBufferPool.buffer().isDirect());
		assertTrue(nettyBufferPool.buffer(128).isDirect());
		assertTrue(nettyBufferPool.buffer(128, 256).isDirect());

		// IO buffers should prefer to be direct
		assertTrue(nettyBufferPool.ioBuffer().isDirect());
		assertTrue(nettyBufferPool.ioBuffer(128).isDirect());
		assertTrue(nettyBufferPool.ioBuffer(128, 256).isDirect());

		// Disallow heap buffers
		try {
			nettyBufferPool.heapBuffer();
			fail("Unexpected heap buffer operation");
		} catch (UnsupportedOperationException ignored) {
		}

		try {
			nettyBufferPool.heapBuffer(128);
			fail("Unexpected heap buffer operation");
		} catch (UnsupportedOperationException ignored) {
		}

		try {
			nettyBufferPool.heapBuffer(128, 256);
			fail("Unexpected heap buffer operation");
		} catch (UnsupportedOperationException ignored) {
		}

		// Disallow composite heap buffers
		try {
			nettyBufferPool.compositeHeapBuffer();
			fail("Unexpected heap buffer operation");
		} catch (UnsupportedOperationException ignored) {
		}

		try {
			nettyBufferPool.compositeHeapBuffer(2);
			fail("Unexpected heap buffer operation");
		} catch (UnsupportedOperationException ignored) {
		}

		// Is direct buffer pooled!
		assertTrue(nettyBufferPool.isDirectBufferPooled());
	}

	@Test
	public void testAllocationsStatistics() throws Exception {
		NettyBufferPool nettyBufferPool = new NettyBufferPool(1);
		int chunkSize = nettyBufferPool.getChunkSize();

		{
			// Single large buffer allocates one chunk
			nettyBufferPool.directBuffer(chunkSize - 64);
			long allocated = nettyBufferPool.getNumberOfAllocatedBytes().get();
			assertEquals(chunkSize, allocated);
		}

		{
			// Allocate a little more (one more chunk required)
			nettyBufferPool.directBuffer(128);
			long allocated = nettyBufferPool.getNumberOfAllocatedBytes().get();
			assertEquals(2 * chunkSize, allocated);
		}
	}
}