/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project 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.jboss.netty.buffer;

import static org.jboss.netty.buffer.ChannelBuffers.*;
import static org.junit.Assert.*;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.HashSet;
import java.util.NoSuchElementException;
import java.util.Random;
import java.util.Set;

import org.jboss.netty.util.CharsetUtil;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

/**
 * An abstract test class for channel buffers
 */
public abstract class AbstractChannelBufferTest {

    private static final int CAPACITY = 4096; // Must be even
    private static final int BLOCK_SIZE = 128;

    private long seed;
    private Random random;
    private ChannelBuffer buffer;

    protected abstract ChannelBuffer newBuffer(int capacity);
    protected abstract ChannelBuffer[] components();

    protected boolean discardReadBytesDoesNotMoveWritableBytes() {
        return true;
    }


    @Before
    public void init() {
        buffer = newBuffer(CAPACITY);
        seed = System.currentTimeMillis();
        random = new Random(seed);
    }

    @After
    public void dispose() {
        buffer = null;
    }

    @Test
    public void initialState() {
        assertEquals(CAPACITY, buffer.capacity());
        assertEquals(0, buffer.readerIndex());
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void readerIndexBoundaryCheck1() {
        try {
            buffer.writerIndex(0);
        } catch (IndexOutOfBoundsException e) {
            fail();
        }
        buffer.readerIndex(-1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void readerIndexBoundaryCheck2() {
        try {
            buffer.writerIndex(buffer.capacity());
        } catch (IndexOutOfBoundsException e) {
            fail();
        }
        buffer.readerIndex(buffer.capacity() + 1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void readerIndexBoundaryCheck3() {
        try {
            buffer.writerIndex(CAPACITY / 2);
        } catch (IndexOutOfBoundsException e) {
            fail();
        }
        buffer.readerIndex(CAPACITY * 3 / 2);
    }

    @Test
    public void readerIndexBoundaryCheck4() {
        buffer.writerIndex(0);
        buffer.readerIndex(0);
        buffer.writerIndex(buffer.capacity());
        buffer.readerIndex(buffer.capacity());
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void writerIndexBoundaryCheck1() {
        buffer.writerIndex(-1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void writerIndexBoundaryCheck2() {
        try {
            buffer.writerIndex(CAPACITY);
            buffer.readerIndex(CAPACITY);
        } catch (IndexOutOfBoundsException e) {
            fail();
        }
        buffer.writerIndex(buffer.capacity() + 1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void writerIndexBoundaryCheck3() {
        try {
            buffer.writerIndex(CAPACITY);
            buffer.readerIndex(CAPACITY / 2);
        } catch (IndexOutOfBoundsException e) {
            fail();
        }
        buffer.writerIndex(CAPACITY / 4);
    }

    @Test
    public void writerIndexBoundaryCheck4() {
        buffer.writerIndex(0);
        buffer.readerIndex(0);
        buffer.writerIndex(CAPACITY);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getByteBoundaryCheck1() {
        buffer.getByte(-1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getByteBoundaryCheck2() {
        buffer.getByte(buffer.capacity());
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getShortBoundaryCheck1() {
        buffer.getShort(-1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getShortBoundaryCheck2() {
        buffer.getShort(buffer.capacity() - 1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getMediumBoundaryCheck1() {
        buffer.getMedium(-1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getMediumBoundaryCheck2() {
        buffer.getMedium(buffer.capacity() - 2);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getIntBoundaryCheck1() {
        buffer.getInt(-1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getIntBoundaryCheck2() {
        buffer.getInt(buffer.capacity() - 3);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getLongBoundaryCheck1() {
        buffer.getLong(-1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getLongBoundaryCheck2() {
        buffer.getLong(buffer.capacity() - 7);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getByteArrayBoundaryCheck1() {
        buffer.getBytes(-1, new byte[0]);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getByteArrayBoundaryCheck2() {
        buffer.getBytes(-1, new byte[0], 0, 0);
    }

    @Test
    public void getByteArrayBoundaryCheck3() {
        byte[] dst = new byte[4];
        buffer.setInt(0, 0x01020304);
        try {
            buffer.getBytes(0, dst, -1, 4);
            fail();
        } catch (IndexOutOfBoundsException e) {
            // Success
        }

        // No partial copy is expected.
        assertEquals(0, dst[0]);
        assertEquals(0, dst[1]);
        assertEquals(0, dst[2]);
        assertEquals(0, dst[3]);
    }

    @Test
    public void getByteArrayBoundaryCheck4() {
        byte[] dst = new byte[4];
        buffer.setInt(0, 0x01020304);
        try {
            buffer.getBytes(0, dst, 1, 4);
            fail();
        } catch (IndexOutOfBoundsException e) {
            // Success
        }

        // No partial copy is expected.
        assertEquals(0, dst[0]);
        assertEquals(0, dst[1]);
        assertEquals(0, dst[2]);
        assertEquals(0, dst[3]);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getByteBufferBoundaryCheck() {
        buffer.getBytes(-1, ByteBuffer.allocate(0));
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void copyBoundaryCheck1() {
        buffer.copy(-1, 0);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void copyBoundaryCheck2() {
        buffer.copy(0, buffer.capacity() + 1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void copyBoundaryCheck3() {
        buffer.copy(buffer.capacity() + 1, 0);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void copyBoundaryCheck4() {
        buffer.copy(buffer.capacity(), 1);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void setIndexBoundaryCheck1() {
        buffer.setIndex(-1, CAPACITY);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void setIndexBoundaryCheck2() {
        buffer.setIndex(CAPACITY / 2, CAPACITY / 4);
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void setIndexBoundaryCheck3() {
        buffer.setIndex(0, CAPACITY + 1);
    }

    @Test
    public void getByteBufferState() {
        ByteBuffer dst = ByteBuffer.allocate(4);
        dst.position(1);
        dst.limit(3);

        buffer.setByte(0, (byte) 1);
        buffer.setByte(1, (byte) 2);
        buffer.setByte(2, (byte) 3);
        buffer.setByte(3, (byte) 4);
        buffer.getBytes(1, dst);

        assertEquals(3, dst.position());
        assertEquals(3, dst.limit());

        dst.clear();
        assertEquals(0, dst.get(0));
        assertEquals(2, dst.get(1));
        assertEquals(3, dst.get(2));
        assertEquals(0, dst.get(3));
    }

    @Test(expected = IndexOutOfBoundsException.class)
    public void getDirectByteBufferBoundaryCheck() {
        buffer.getBytes(-1, ByteBuffer.allocateDirect(0));
    }

    @Test
    public void getDirectByteBufferState() {
        ByteBuffer dst = ByteBuffer.allocateDirect(4);
        dst.position(1);
        dst.limit(3);

        buffer.setByte(0, (byte) 1);
        buffer.setByte(1, (byte) 2);
        buffer.setByte(2, (byte) 3);
        buffer.setByte(3, (byte) 4);
        buffer.getBytes(1, dst);

        assertEquals(3, dst.position());
        assertEquals(3, dst.limit());

        dst.clear();
        assertEquals(0, dst.get(0));
        assertEquals(2, dst.get(1));
        assertEquals(3, dst.get(2));
        assertEquals(0, dst.get(3));
    }

    @Test
    public void testRandomByteAccess() {
        for (int i = 0; i < buffer.capacity(); i ++) {
            byte value = (byte) random.nextInt();
            buffer.setByte(i, value);
        }

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity(); i ++) {
            byte value = (byte) random.nextInt();
            assertEquals(value, buffer.getByte(i));
        }
    }

    @Test
    public void testRandomUnsignedByteAccess() {
        for (int i = 0; i < buffer.capacity(); i ++) {
            byte value = (byte) random.nextInt();
            buffer.setByte(i, value);
        }

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity(); i ++) {
            int value = random.nextInt() & 0xFF;
            assertEquals(value, buffer.getUnsignedByte(i));
        }
    }

    @Test
    public void testRandomShortAccess() {
        for (int i = 0; i < buffer.capacity() - 1; i += 2) {
            short value = (short) random.nextInt();
            buffer.setShort(i, value);
        }

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity() - 1; i += 2) {
            short value = (short) random.nextInt();
            assertEquals(value, buffer.getShort(i));
        }
    }

    @Test
    public void testRandomUnsignedShortAccess() {
        for (int i = 0; i < buffer.capacity() - 1; i += 2) {
            short value = (short) random.nextInt();
            buffer.setShort(i, value);
        }

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity() - 1; i += 2) {
            int value = random.nextInt() & 0xFFFF;
            assertEquals(value, buffer.getUnsignedShort(i));
        }
    }

    @Test
    public void testRandomMediumAccess() {
        for (int i = 0; i < buffer.capacity() - 2; i += 3) {
            int value = random.nextInt();
            buffer.setMedium(i, value);
        }

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity() - 2; i += 3) {
            int value = random.nextInt() << 8 >> 8;
            assertEquals(value, buffer.getMedium(i));
        }
    }

    @Test
    public void testRandomUnsignedMediumAccess() {
        for (int i = 0; i < buffer.capacity() - 2; i += 3) {
            int value = random.nextInt();
            buffer.setMedium(i, value);
        }

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity() - 2; i += 3) {
            int value = random.nextInt() & 0x00FFFFFF;
            assertEquals(value, buffer.getUnsignedMedium(i));
        }
    }

    @Test
    public void testRandomIntAccess() {
        for (int i = 0; i < buffer.capacity() - 3; i += 4) {
            int value = random.nextInt();
            buffer.setInt(i, value);
        }

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity() - 3; i += 4) {
            int value = random.nextInt();
            assertEquals(value, buffer.getInt(i));
        }
    }

    @Test
    public void testRandomUnsignedIntAccess() {
        for (int i = 0; i < buffer.capacity() - 3; i += 4) {
            int value = random.nextInt();
            buffer.setInt(i, value);
        }

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity() - 3; i += 4) {
            long value = random.nextInt() & 0xFFFFFFFFL;
            assertEquals(value, buffer.getUnsignedInt(i));
        }
    }

    @Test
    public void testRandomLongAccess() {
        for (int i = 0; i < buffer.capacity() - 7; i += 8) {
            long value = random.nextLong();
            buffer.setLong(i, value);
        }

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity() - 7; i += 8) {
            long value = random.nextLong();
            assertEquals(value, buffer.getLong(i));
        }
    }

    @Test
    public void testSetZero() {
        buffer.clear();
        while (buffer.writable()) {
            buffer.writeByte((byte) 0xFF);
        }

        for (int i = 0; i < buffer.capacity();) {
            int length = Math.min(buffer.capacity() - i, random.nextInt(32));
            buffer.setZero(i, length);
            i += length;
        }

        for (int i = 0; i < buffer.capacity(); i ++) {
            assertEquals(0, buffer.getByte(i));
        }
    }

    @Test
    public void testSequentialByteAccess() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity(); i ++) {
            byte value = (byte) random.nextInt();
            assertEquals(i, buffer.writerIndex());
            assertTrue(buffer.writable());
            buffer.writeByte(value);
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.writable());

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity(); i ++) {
            byte value = (byte) random.nextInt();
            assertEquals(i, buffer.readerIndex());
            assertTrue(buffer.readable());
            assertEquals(value, buffer.readByte());
        }

        assertEquals(buffer.capacity(), buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.readable());
        assertFalse(buffer.writable());
    }

    @Test
    public void testSequentialUnsignedByteAccess() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity(); i ++) {
            byte value = (byte) random.nextInt();
            assertEquals(i, buffer.writerIndex());
            assertTrue(buffer.writable());
            buffer.writeByte(value);
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.writable());

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity(); i ++) {
            int value = random.nextInt() & 0xFF;
            assertEquals(i, buffer.readerIndex());
            assertTrue(buffer.readable());
            assertEquals(value, buffer.readUnsignedByte());
        }

        assertEquals(buffer.capacity(), buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.readable());
        assertFalse(buffer.writable());
    }

    @Test
    public void testSequentialShortAccess() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity(); i += 2) {
            short value = (short) random.nextInt();
            assertEquals(i, buffer.writerIndex());
            assertTrue(buffer.writable());
            buffer.writeShort(value);
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.writable());

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity(); i += 2) {
            short value = (short) random.nextInt();
            assertEquals(i, buffer.readerIndex());
            assertTrue(buffer.readable());
            assertEquals(value, buffer.readShort());
        }

        assertEquals(buffer.capacity(), buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.readable());
        assertFalse(buffer.writable());
    }

    @Test
    public void testSequentialUnsignedShortAccess() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity(); i += 2) {
            short value = (short) random.nextInt();
            assertEquals(i, buffer.writerIndex());
            assertTrue(buffer.writable());
            buffer.writeShort(value);
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.writable());

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity(); i += 2) {
            int value = random.nextInt() & 0xFFFF;
            assertEquals(i, buffer.readerIndex());
            assertTrue(buffer.readable());
            assertEquals(value, buffer.readUnsignedShort());
        }

        assertEquals(buffer.capacity(), buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.readable());
        assertFalse(buffer.writable());
    }

    @Test
    public void testSequentialMediumAccess() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() / 3 * 3; i += 3) {
            int value = random.nextInt();
            assertEquals(i, buffer.writerIndex());
            assertTrue(buffer.writable());
            buffer.writeMedium(value);
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity() / 3 * 3, buffer.writerIndex());
        assertEquals(buffer.capacity() % 3, buffer.writableBytes());

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity() / 3 * 3; i += 3) {
            int value = random.nextInt() << 8 >> 8;
            assertEquals(i, buffer.readerIndex());
            assertTrue(buffer.readable());
            assertEquals(value, buffer.readMedium());
        }

        assertEquals(buffer.capacity() / 3 * 3, buffer.readerIndex());
        assertEquals(buffer.capacity() / 3 * 3, buffer.writerIndex());
        assertEquals(0, buffer.readableBytes());
        assertEquals(buffer.capacity() % 3, buffer.writableBytes());
    }

    @Test
    public void testSequentialUnsignedMediumAccess() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() / 3 * 3; i += 3) {
            int value = random.nextInt() & 0x00FFFFFF;
            assertEquals(i, buffer.writerIndex());
            assertTrue(buffer.writable());
            buffer.writeMedium(value);
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity() / 3 * 3, buffer.writerIndex());
        assertEquals(buffer.capacity() % 3, buffer.writableBytes());

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity() / 3 * 3; i += 3) {
            int value = random.nextInt() & 0x00FFFFFF;
            assertEquals(i, buffer.readerIndex());
            assertTrue(buffer.readable());
            assertEquals(value, buffer.readUnsignedMedium());
        }

        assertEquals(buffer.capacity() / 3 * 3, buffer.readerIndex());
        assertEquals(buffer.capacity() / 3 * 3, buffer.writerIndex());
        assertEquals(0, buffer.readableBytes());
        assertEquals(buffer.capacity() % 3, buffer.writableBytes());
    }

    @Test
    public void testSequentialIntAccess() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity(); i += 4) {
            int value = random.nextInt();
            assertEquals(i, buffer.writerIndex());
            assertTrue(buffer.writable());
            buffer.writeInt(value);
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.writable());

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity(); i += 4) {
            int value = random.nextInt();
            assertEquals(i, buffer.readerIndex());
            assertTrue(buffer.readable());
            assertEquals(value, buffer.readInt());
        }

        assertEquals(buffer.capacity(), buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.readable());
        assertFalse(buffer.writable());
    }

    @Test
    public void testSequentialUnsignedIntAccess() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity(); i += 4) {
            int value = random.nextInt();
            assertEquals(i, buffer.writerIndex());
            assertTrue(buffer.writable());
            buffer.writeInt(value);
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.writable());

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity(); i += 4) {
            long value = random.nextInt() & 0xFFFFFFFFL;
            assertEquals(i, buffer.readerIndex());
            assertTrue(buffer.readable());
            assertEquals(value, buffer.readUnsignedInt());
        }

        assertEquals(buffer.capacity(), buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.readable());
        assertFalse(buffer.writable());
    }

    @Test
    public void testSequentialLongAccess() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity(); i += 8) {
            long value = random.nextLong();
            assertEquals(i, buffer.writerIndex());
            assertTrue(buffer.writable());
            buffer.writeLong(value);
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.writable());

        random.setSeed(seed);
        for (int i = 0; i < buffer.capacity(); i += 8) {
            long value = random.nextLong();
            assertEquals(i, buffer.readerIndex());
            assertTrue(buffer.readable());
            assertEquals(value, buffer.readLong());
        }

        assertEquals(buffer.capacity(), buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());
        assertFalse(buffer.readable());
        assertFalse(buffer.writable());
    }

    @Test
    public void testByteArrayTransfer() {
        byte[] value = new byte[BLOCK_SIZE * 2];
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(value);
            buffer.setBytes(i, value, random.nextInt(BLOCK_SIZE), BLOCK_SIZE);
        }

        random.setSeed(seed);
        byte[] expectedValue = new byte[BLOCK_SIZE * 2];
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValue);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            buffer.getBytes(i, value, valueOffset, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue[j], value[j]);
            }
        }
    }

    @Test
    public void testRandomByteArrayTransfer1() {
        byte[] value = new byte[BLOCK_SIZE];
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(value);
            buffer.setBytes(i, value);
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            buffer.getBytes(i, value);
            for (int j = 0; j < BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value[j]);
            }
        }
    }

    @Test
    public void testRandomByteArrayTransfer2() {
        byte[] value = new byte[BLOCK_SIZE * 2];
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(value);
            buffer.setBytes(i, value, random.nextInt(BLOCK_SIZE), BLOCK_SIZE);
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            buffer.getBytes(i, value, valueOffset, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value[j]);
            }
        }
    }

    @Test
    public void testRandomHeapBufferTransfer1() {
        byte[] valueContent = new byte[BLOCK_SIZE];
        ChannelBuffer value = wrappedBuffer(valueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(valueContent);
            value.setIndex(0, BLOCK_SIZE);
            buffer.setBytes(i, value);
            assertEquals(BLOCK_SIZE, value.readerIndex());
            assertEquals(BLOCK_SIZE, value.writerIndex());
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            value.clear();
            buffer.getBytes(i, value);
            assertEquals(0, value.readerIndex());
            assertEquals(BLOCK_SIZE, value.writerIndex());
            for (int j = 0; j < BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value.getByte(j));
            }
        }
    }

    @Test
    public void testRandomHeapBufferTransfer2() {
        byte[] valueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer value = wrappedBuffer(valueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(valueContent);
            buffer.setBytes(i, value, random.nextInt(BLOCK_SIZE), BLOCK_SIZE);
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            buffer.getBytes(i, value, valueOffset, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value.getByte(j));
            }
        }
    }

    @Test
    public void testRandomDirectBufferTransfer() {
        byte[] tmp = new byte[BLOCK_SIZE * 2];
        ChannelBuffer value = directBuffer(BLOCK_SIZE * 2);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(tmp);
            value.setBytes(0, tmp, 0, value.capacity());
            buffer.setBytes(i, value, random.nextInt(BLOCK_SIZE), BLOCK_SIZE);
        }

        random.setSeed(seed);
        ChannelBuffer expectedValue = directBuffer(BLOCK_SIZE * 2);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(tmp);
            expectedValue.setBytes(0, tmp, 0, expectedValue.capacity());
            int valueOffset = random.nextInt(BLOCK_SIZE);
            buffer.getBytes(i, value, valueOffset, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value.getByte(j));
            }
        }
    }

    @Test
    public void testRandomByteBufferTransfer() {
        ByteBuffer value = ByteBuffer.allocate(BLOCK_SIZE * 2);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(value.array());
            value.clear().position(random.nextInt(BLOCK_SIZE));
            value.limit(value.position() + BLOCK_SIZE);
            buffer.setBytes(i, value);
        }

        random.setSeed(seed);
        ByteBuffer expectedValue = ByteBuffer.allocate(BLOCK_SIZE * 2);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValue.array());
            int valueOffset = random.nextInt(BLOCK_SIZE);
            value.clear().position(valueOffset).limit(valueOffset + BLOCK_SIZE);
            buffer.getBytes(i, value);
            assertEquals(valueOffset + BLOCK_SIZE, value.position());
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.get(j), value.get(j));
            }
        }
    }

    @Test
    public void testSequentialByteArrayTransfer1() {
        byte[] value = new byte[BLOCK_SIZE];
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(value);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            buffer.writeBytes(value);
        }

        random.setSeed(seed);
        byte[] expectedValue = new byte[BLOCK_SIZE];
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValue);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            buffer.readBytes(value);
            for (int j = 0; j < BLOCK_SIZE; j ++) {
                assertEquals(expectedValue[j], value[j]);
            }
        }
    }

    @Test
    public void testSequentialByteArrayTransfer2() {
        byte[] value = new byte[BLOCK_SIZE * 2];
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(value);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            int readerIndex = random.nextInt(BLOCK_SIZE);
            buffer.writeBytes(value, readerIndex, BLOCK_SIZE);
        }

        random.setSeed(seed);
        byte[] expectedValue = new byte[BLOCK_SIZE * 2];
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValue);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            buffer.readBytes(value, valueOffset, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue[j], value[j]);
            }
        }
    }

    @Test
    public void testSequentialHeapBufferTransfer1() {
        byte[] valueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer value = wrappedBuffer(valueContent);
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(valueContent);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            buffer.writeBytes(value, random.nextInt(BLOCK_SIZE), BLOCK_SIZE);
            assertEquals(0, value.readerIndex());
            assertEquals(valueContent.length, value.writerIndex());
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            buffer.readBytes(value, valueOffset, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value.getByte(j));
            }
            assertEquals(0, value.readerIndex());
            assertEquals(valueContent.length, value.writerIndex());
        }
    }

    @Test
    public void testSequentialHeapBufferTransfer2() {
        byte[] valueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer value = wrappedBuffer(valueContent);
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(valueContent);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            int readerIndex = random.nextInt(BLOCK_SIZE);
            value.readerIndex(readerIndex);
            value.writerIndex(readerIndex + BLOCK_SIZE);
            buffer.writeBytes(value);
            assertEquals(readerIndex + BLOCK_SIZE, value.writerIndex());
            assertEquals(value.writerIndex(), value.readerIndex());
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            value.readerIndex(valueOffset);
            value.writerIndex(valueOffset);
            buffer.readBytes(value, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value.getByte(j));
            }
            assertEquals(valueOffset, value.readerIndex());
            assertEquals(valueOffset + BLOCK_SIZE, value.writerIndex());
        }
    }

    @Test
    public void testSequentialDirectBufferTransfer1() {
        byte[] valueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer value = directBuffer(BLOCK_SIZE * 2);
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(valueContent);
            value.setBytes(0, valueContent);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            buffer.writeBytes(value, random.nextInt(BLOCK_SIZE), BLOCK_SIZE);
            assertEquals(0, value.readerIndex());
            assertEquals(0, value.writerIndex());
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            value.setBytes(0, valueContent);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            buffer.readBytes(value, valueOffset, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value.getByte(j));
            }
            assertEquals(0, value.readerIndex());
            assertEquals(0, value.writerIndex());
        }
    }

    @Test
    public void testSequentialDirectBufferTransfer2() {
        byte[] valueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer value = directBuffer(BLOCK_SIZE * 2);
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(valueContent);
            value.setBytes(0, valueContent);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            int readerIndex = random.nextInt(BLOCK_SIZE);
            value.readerIndex(0);
            value.writerIndex(readerIndex + BLOCK_SIZE);
            value.readerIndex(readerIndex);
            buffer.writeBytes(value);
            assertEquals(readerIndex + BLOCK_SIZE, value.writerIndex());
            assertEquals(value.writerIndex(), value.readerIndex());
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            value.setBytes(0, valueContent);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            value.readerIndex(valueOffset);
            value.writerIndex(valueOffset);
            buffer.readBytes(value, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value.getByte(j));
            }
            assertEquals(valueOffset, value.readerIndex());
            assertEquals(valueOffset + BLOCK_SIZE, value.writerIndex());
        }
    }

    @Test
    public void testSequentialByteBufferBackedHeapBufferTransfer1() {
        byte[] valueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer value = wrappedBuffer(ByteBuffer.allocate(BLOCK_SIZE * 2));
        value.writerIndex(0);
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(valueContent);
            value.setBytes(0, valueContent);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            buffer.writeBytes(value, random.nextInt(BLOCK_SIZE), BLOCK_SIZE);
            assertEquals(0, value.readerIndex());
            assertEquals(0, value.writerIndex());
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            value.setBytes(0, valueContent);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            buffer.readBytes(value, valueOffset, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value.getByte(j));
            }
            assertEquals(0, value.readerIndex());
            assertEquals(0, value.writerIndex());
        }
    }

    @Test
    public void testSequentialByteBufferBackedHeapBufferTransfer2() {
        byte[] valueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer value = wrappedBuffer(ByteBuffer.allocate(BLOCK_SIZE * 2));
        value.writerIndex(0);
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(valueContent);
            value.setBytes(0, valueContent);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            int readerIndex = random.nextInt(BLOCK_SIZE);
            value.readerIndex(0);
            value.writerIndex(readerIndex + BLOCK_SIZE);
            value.readerIndex(readerIndex);
            buffer.writeBytes(value);
            assertEquals(readerIndex + BLOCK_SIZE, value.writerIndex());
            assertEquals(value.writerIndex(), value.readerIndex());
        }

        random.setSeed(seed);
        byte[] expectedValueContent = new byte[BLOCK_SIZE * 2];
        ChannelBuffer expectedValue = wrappedBuffer(expectedValueContent);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValueContent);
            value.setBytes(0, valueContent);
            int valueOffset = random.nextInt(BLOCK_SIZE);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            value.readerIndex(valueOffset);
            value.writerIndex(valueOffset);
            buffer.readBytes(value, BLOCK_SIZE);
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.getByte(j), value.getByte(j));
            }
            assertEquals(valueOffset, value.readerIndex());
            assertEquals(valueOffset + BLOCK_SIZE, value.writerIndex());
        }
    }

    @Test
    public void testSequentialByteBufferTransfer() {
        buffer.writerIndex(0);
        ByteBuffer value = ByteBuffer.allocate(BLOCK_SIZE * 2);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(value.array());
            value.clear().position(random.nextInt(BLOCK_SIZE));
            value.limit(value.position() + BLOCK_SIZE);
            buffer.writeBytes(value);
        }

        random.setSeed(seed);
        ByteBuffer expectedValue = ByteBuffer.allocate(BLOCK_SIZE * 2);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValue.array());
            int valueOffset = random.nextInt(BLOCK_SIZE);
            value.clear().position(valueOffset).limit(valueOffset + BLOCK_SIZE);
            buffer.readBytes(value);
            assertEquals(valueOffset + BLOCK_SIZE, value.position());
            for (int j = valueOffset; j < valueOffset + BLOCK_SIZE; j ++) {
                assertEquals(expectedValue.get(j), value.get(j));
            }
        }
    }

    @Test
    public void testSequentialCopiedBufferTransfer1() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            byte[] value = new byte[BLOCK_SIZE];
            random.nextBytes(value);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            buffer.writeBytes(value);
        }

        random.setSeed(seed);
        byte[] expectedValue = new byte[BLOCK_SIZE];
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValue);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            ChannelBuffer actualValue = buffer.readBytes(BLOCK_SIZE);
            assertEquals(wrappedBuffer(expectedValue), actualValue);

            // Make sure if it is a copied buffer.
            actualValue.setByte(0, (byte) (actualValue.getByte(0) + 1));
            assertFalse(buffer.getByte(i) == actualValue.getByte(0));
        }
    }

    @Test
    @SuppressWarnings("deprecation")
    public void testSequentialCopiedBufferTransfer2() {
        buffer.clear();
        buffer.writeZero(buffer.capacity());
        try {
            buffer.readBytes(ChannelBufferIndexFinder.CR);
            fail();
        } catch (NoSuchElementException e) {
            // Expected
        }

        assertSame(EMPTY_BUFFER, buffer.readBytes(ChannelBufferIndexFinder.NUL));

        buffer.clear();
        buffer.writeBytes(new byte[] { 1, 2, 3, 4, 0 });

        ChannelBuffer copy = buffer.readBytes(ChannelBufferIndexFinder.NUL);
        assertEquals(wrappedBuffer(new byte[] { 1, 2, 3, 4 }), copy);

        // Make sure if it is a copied buffer.
        copy.setByte(0, (byte) (copy.getByte(0) + 1));
        assertFalse(buffer.getByte(0) == copy.getByte(0));
    }

    @Test
    public void testSequentialSlice1() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            byte[] value = new byte[BLOCK_SIZE];
            random.nextBytes(value);
            assertEquals(0, buffer.readerIndex());
            assertEquals(i, buffer.writerIndex());
            buffer.writeBytes(value);
        }

        random.setSeed(seed);
        byte[] expectedValue = new byte[BLOCK_SIZE];
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            random.nextBytes(expectedValue);
            assertEquals(i, buffer.readerIndex());
            assertEquals(CAPACITY, buffer.writerIndex());
            ChannelBuffer actualValue = buffer.readSlice(BLOCK_SIZE);
            assertEquals(wrappedBuffer(expectedValue), actualValue);

            // Make sure if it is a sliced buffer.
            actualValue.setByte(0, (byte) (actualValue.getByte(0) + 1));
            assertEquals(buffer.getByte(i), actualValue.getByte(0));
        }
    }

    @Test
    @SuppressWarnings("deprecation")
    public void testSequentialSlice2() {
        buffer.clear();
        buffer.writeZero(buffer.capacity());
        try {
            buffer.readSlice(ChannelBufferIndexFinder.CR);
            fail();
        } catch (NoSuchElementException e) {
            // Expected
        }

        assertSame(EMPTY_BUFFER, buffer.readSlice(ChannelBufferIndexFinder.NUL));

        buffer.clear();
        buffer.writeBytes(new byte[] { 1, 2, 3, 4, 0 });

        ChannelBuffer slice = buffer.readSlice(ChannelBufferIndexFinder.NUL);
        assertEquals(wrappedBuffer(new byte[] { 1, 2, 3, 4 }), slice);

        // Make sure if it is a sliced buffer.
        slice.setByte(0, (byte) (slice.getByte(0) + 1));
        assertTrue(buffer.getByte(0) == slice.getByte(0));
    }

    @Test
    public void testWriteZero() {
        try {
            buffer.writeZero(-1);
            fail();
        } catch (IllegalArgumentException e) {
            // Expected
        }

        buffer.clear();
        while (buffer.writable()) {
            buffer.writeByte((byte) 0xFF);
        }

        buffer.clear();
        for (int i = 0; i < buffer.capacity();) {
            int length = Math.min(buffer.capacity() - i, random.nextInt(32));
            buffer.writeZero(length);
            i += length;
        }

        assertEquals(0, buffer.readerIndex());
        assertEquals(buffer.capacity(), buffer.writerIndex());

        for (int i = 0; i < buffer.capacity(); i ++) {
            assertEquals(0, buffer.getByte(i));
        }
    }

    @Test
    public void testDiscardReadBytes() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity(); i += 4) {
            buffer.writeInt(i);
        }
        ChannelBuffer copy = copiedBuffer(buffer);

        // Make sure there's no effect if called when readerIndex is 0.
        buffer.readerIndex(CAPACITY / 4);
        buffer.markReaderIndex();
        buffer.writerIndex(CAPACITY / 3);
        buffer.markWriterIndex();
        buffer.readerIndex(0);
        buffer.writerIndex(CAPACITY / 2);
        buffer.discardReadBytes();

        assertEquals(0, buffer.readerIndex());
        assertEquals(CAPACITY / 2, buffer.writerIndex());
        assertEquals(copy.slice(0, CAPACITY / 2), buffer.slice(0, CAPACITY / 2));
        buffer.resetReaderIndex();
        assertEquals(CAPACITY / 4, buffer.readerIndex());
        buffer.resetWriterIndex();
        assertEquals(CAPACITY / 3, buffer.writerIndex());

        // Make sure bytes after writerIndex is not copied.
        buffer.readerIndex(1);
        buffer.writerIndex(CAPACITY / 2);
        buffer.discardReadBytes();

        assertEquals(0, buffer.readerIndex());
        assertEquals(CAPACITY / 2 - 1, buffer.writerIndex());
        assertEquals(copy.slice(1, CAPACITY / 2 - 1), buffer.slice(0, CAPACITY / 2 - 1));

        if (discardReadBytesDoesNotMoveWritableBytes()) {
            // If writable bytes were copied, the test should fail to avoid unnecessary memory bandwidth consumption.
            assertFalse(copy.slice(CAPACITY / 2, CAPACITY / 2).equals(buffer.slice(CAPACITY / 2 - 1, CAPACITY / 2)));
        } else {
            assertEquals(copy.slice(CAPACITY / 2, CAPACITY / 2), buffer.slice(CAPACITY / 2 - 1, CAPACITY / 2));
        }

        // Marks also should be relocated.
        buffer.resetReaderIndex();
        assertEquals(CAPACITY / 4 - 1, buffer.readerIndex());
        buffer.resetWriterIndex();
        assertEquals(CAPACITY / 3 - 1, buffer.writerIndex());
    }

    /**
     * The similar test case with {@link #testDiscardReadBytes()} but this one
     * discards a large chunk at once.
     */
    @Test
    public void testDiscardReadBytes2() {
        buffer.writerIndex(0);
        for (int i = 0; i < buffer.capacity(); i ++) {
            buffer.writeByte((byte) i);
        }
        ChannelBuffer copy = copiedBuffer(buffer);

        // Discard the first (CAPACITY / 2 - 1) bytes.
        buffer.setIndex(CAPACITY / 2 - 1, CAPACITY - 1);
        buffer.discardReadBytes();
        assertEquals(0, buffer.readerIndex());
        assertEquals(CAPACITY / 2, buffer.writerIndex());
        for (int i = 0; i < CAPACITY / 2; i ++) {
            assertEquals(copy.slice(CAPACITY / 2 - 1 + i, CAPACITY / 2 - i), buffer.slice(i, CAPACITY / 2 - i));
        }
    }

    @Test
    public void testStreamTransfer1() throws Exception {
        byte[] expected = new byte[buffer.capacity()];
        random.nextBytes(expected);

        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            ByteArrayInputStream in = new ByteArrayInputStream(expected, i, BLOCK_SIZE);
            assertEquals(BLOCK_SIZE, buffer.setBytes(i, in, BLOCK_SIZE));
            assertEquals(-1, buffer.setBytes(i, in, 0));
        }

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            buffer.getBytes(i, out, BLOCK_SIZE);
        }

        assertTrue(Arrays.equals(expected, out.toByteArray()));
    }

    @Test
    public void testStreamTransfer2() throws Exception {
        byte[] expected = new byte[buffer.capacity()];
        random.nextBytes(expected);
        buffer.clear();

        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            ByteArrayInputStream in = new ByteArrayInputStream(expected, i, BLOCK_SIZE);
            assertEquals(i, buffer.writerIndex());
            buffer.writeBytes(in, BLOCK_SIZE);
            assertEquals(i + BLOCK_SIZE, buffer.writerIndex());
        }

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            assertEquals(i, buffer.readerIndex());
            buffer.readBytes(out, BLOCK_SIZE);
            assertEquals(i + BLOCK_SIZE, buffer.readerIndex());
        }

        assertTrue(Arrays.equals(expected, out.toByteArray()));
    }

    @Test
    public void testCopy() {
        for (int i = 0; i < buffer.capacity(); i ++) {
            byte value = (byte) random.nextInt();
            buffer.setByte(i, value);
        }

        final int readerIndex = CAPACITY / 3;
        final int writerIndex = CAPACITY * 2 / 3;
        buffer.setIndex(readerIndex, writerIndex);

        // Make sure all properties are copied.
        ChannelBuffer copy = buffer.copy();
        assertEquals(0, copy.readerIndex());
        assertEquals(buffer.readableBytes(), copy.writerIndex());
        assertEquals(buffer.readableBytes(), copy.capacity());
        assertSame(buffer.order(), copy.order());
        for (int i = 0; i < copy.capacity(); i ++) {
            assertEquals(buffer.getByte(i + readerIndex), copy.getByte(i));
        }

        // Make sure the buffer content is independent from each other.
        buffer.setByte(readerIndex, (byte) (buffer.getByte(readerIndex) + 1));
        assertTrue(buffer.getByte(readerIndex) != copy.getByte(0));
        copy.setByte(1, (byte) (copy.getByte(1) + 1));
        assertTrue(buffer.getByte(readerIndex + 1) != copy.getByte(1));
    }

    @Test
    public void testDuplicate() {
        for (int i = 0; i < buffer.capacity(); i ++) {
            byte value = (byte) random.nextInt();
            buffer.setByte(i, value);
        }

        final int readerIndex = CAPACITY / 3;
        final int writerIndex = CAPACITY * 2 / 3;
        buffer.setIndex(readerIndex, writerIndex);

        // Make sure all properties are copied.
        ChannelBuffer duplicate = buffer.duplicate();
        assertEquals(buffer.readerIndex(), duplicate.readerIndex());
        assertEquals(buffer.writerIndex(), duplicate.writerIndex());
        assertEquals(buffer.capacity(), duplicate.capacity());
        assertSame(buffer.order(), duplicate.order());
        for (int i = 0; i < duplicate.capacity(); i ++) {
            assertEquals(buffer.getByte(i), duplicate.getByte(i));
        }

        // Make sure the buffer content is shared.
        buffer.setByte(readerIndex, (byte) (buffer.getByte(readerIndex) + 1));
        assertTrue(buffer.getByte(readerIndex) == duplicate.getByte(readerIndex));
        duplicate.setByte(1, (byte) (duplicate.getByte(1) + 1));
        assertTrue(buffer.getByte(1) == duplicate.getByte(1));
    }

    @Test
    public void testSliceEndianness() throws Exception {
        assertEquals(buffer.order(), buffer.slice(0, buffer.capacity()).order());
        assertEquals(buffer.order(), buffer.slice(0, buffer.capacity() - 1).order());
        assertEquals(buffer.order(), buffer.slice(1, buffer.capacity() - 1).order());
        assertEquals(buffer.order(), buffer.slice(1, buffer.capacity() - 2).order());
    }

    @Test
    public void testSliceIndex() throws Exception {
        assertEquals(0, buffer.slice(0, buffer.capacity()).readerIndex());
        assertEquals(0, buffer.slice(0, buffer.capacity() - 1).readerIndex());
        assertEquals(0, buffer.slice(1, buffer.capacity() - 1).readerIndex());
        assertEquals(0, buffer.slice(1, buffer.capacity() - 2).readerIndex());

        assertEquals(buffer.capacity(), buffer.slice(0, buffer.capacity()).writerIndex());
        assertEquals(buffer.capacity() - 1, buffer.slice(0, buffer.capacity() - 1).writerIndex());
        assertEquals(buffer.capacity() - 1, buffer.slice(1, buffer.capacity() - 1).writerIndex());
        assertEquals(buffer.capacity() - 2, buffer.slice(1, buffer.capacity() - 2).writerIndex());
    }

    @Test
    public void testEquals() {
        assertFalse(buffer.equals(null));
        assertFalse(buffer.equals(new Object()));

        byte[] value = new byte[32];
        buffer.setIndex(0, value.length);
        random.nextBytes(value);
        buffer.setBytes(0, value);

        assertEquals(buffer, wrappedBuffer(BIG_ENDIAN, value));
        assertEquals(buffer, wrappedBuffer(LITTLE_ENDIAN, value));

        value[0] ++;
        assertFalse(buffer.equals(wrappedBuffer(BIG_ENDIAN, value)));
        assertFalse(buffer.equals(wrappedBuffer(LITTLE_ENDIAN, value)));
    }

    @Test
    public void testCompareTo() {
        try {
            buffer.compareTo(null);
            fail();
        } catch (NullPointerException e) {
            // Expected
        }

        // Fill the random stuff
        byte[] value = new byte[32];
        random.nextBytes(value);
        // Prevent overflow / underflow
        if (value[0] == 0) {
            value[0] ++;
        } else if (value[0] == -1) {
            value[0] --;
        }

        buffer.setIndex(0, value.length);
        buffer.setBytes(0, value);


        assertEquals(0, buffer.compareTo(wrappedBuffer(BIG_ENDIAN, value)));
        assertEquals(0, buffer.compareTo(wrappedBuffer(LITTLE_ENDIAN, value)));

        value[0] ++;
        assertTrue(buffer.compareTo(wrappedBuffer(BIG_ENDIAN, value)) < 0);
        assertTrue(buffer.compareTo(wrappedBuffer(LITTLE_ENDIAN, value)) < 0);
        value[0] -= 2;
        assertTrue(buffer.compareTo(wrappedBuffer(BIG_ENDIAN, value)) > 0);
        assertTrue(buffer.compareTo(wrappedBuffer(LITTLE_ENDIAN, value)) > 0);
        value[0] ++;

        assertTrue(buffer.compareTo(wrappedBuffer(BIG_ENDIAN, value, 0, 31)) > 0);
        assertTrue(buffer.compareTo(wrappedBuffer(LITTLE_ENDIAN, value, 0, 31)) > 0);
        assertTrue(buffer.slice(0, 31).compareTo(wrappedBuffer(BIG_ENDIAN, value)) < 0);
        assertTrue(buffer.slice(0, 31).compareTo(wrappedBuffer(LITTLE_ENDIAN, value)) < 0);
    }

    @Test
    public void testToString() {
        buffer.clear();
        buffer.writeBytes(copiedBuffer("Hello, World!", CharsetUtil.ISO_8859_1));
        assertEquals("Hello, World!", buffer.toString(CharsetUtil.ISO_8859_1));
    }

    @Test
    public void testIndexOf() {
        buffer.clear();
        buffer.writeByte((byte) 1);
        buffer.writeByte((byte) 2);
        buffer.writeByte((byte) 3);
        buffer.writeByte((byte) 2);
        buffer.writeByte((byte) 1);

        assertEquals(-1, buffer.indexOf(1, 4, (byte) 1));
        assertEquals(-1, buffer.indexOf(4, 1, (byte) 1));
        assertEquals(1, buffer.indexOf(1, 4, (byte) 2));
        assertEquals(3, buffer.indexOf(4, 1, (byte) 2));
    }

    @Test
    public void testToByteBuffer1() {
        byte[] value = new byte[buffer.capacity()];
        random.nextBytes(value);
        buffer.clear();
        buffer.writeBytes(value);

        assertEquals(ByteBuffer.wrap(value), buffer.toByteBuffer());
    }

    @Test
    public void testToByteBuffer2() {
        byte[] value = new byte[buffer.capacity()];
        random.nextBytes(value);
        buffer.clear();
        buffer.writeBytes(value);

        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            assertEquals(ByteBuffer.wrap(value, i, BLOCK_SIZE), buffer.toByteBuffer(i, BLOCK_SIZE));
        }
    }

    @Test
    public void testToByteBuffer3() {
        assertEquals(buffer.order(), buffer.toByteBuffer().order());
    }

    @Test
    public void testToByteBuffers1() {
        byte[] value = new byte[buffer.capacity()];
        random.nextBytes(value);
        buffer.clear();
        buffer.writeBytes(value);

        ByteBuffer[] nioBuffers = buffer.toByteBuffers();
        int length = 0;
        for (ByteBuffer b: nioBuffers) {
            length += b.remaining();
        }

        ByteBuffer nioBuffer = ByteBuffer.allocate(length);
        for (ByteBuffer b: nioBuffers) {
            nioBuffer.put(b);
        }
        nioBuffer.flip();

        assertEquals(ByteBuffer.wrap(value), nioBuffer);
    }

    @Test
    public void testToByteBuffers2() {
        byte[] value = new byte[buffer.capacity()];
        random.nextBytes(value);
        buffer.clear();
        buffer.writeBytes(value);

        for (int i = 0; i < buffer.capacity() - BLOCK_SIZE + 1; i += BLOCK_SIZE) {
            ByteBuffer[] nioBuffers = buffer.toByteBuffers(i, BLOCK_SIZE);
            ByteBuffer nioBuffer = ByteBuffer.allocate(BLOCK_SIZE);
            for (ByteBuffer b: nioBuffers) {
                nioBuffer.put(b);
            }
            nioBuffer.flip();

            assertEquals(ByteBuffer.wrap(value, i, BLOCK_SIZE), nioBuffer);
        }
    }

    @Test
    public void testSkipBytes1() {
        buffer.setIndex(CAPACITY / 4, CAPACITY / 2);

        buffer.skipBytes(CAPACITY / 4);
        assertEquals(CAPACITY / 4 * 2, buffer.readerIndex());

        try {
            buffer.skipBytes(CAPACITY / 4 + 1);
            fail();
        } catch (IndexOutOfBoundsException e) {
            // Expected
        }

        // Should remain unchanged.
        assertEquals(CAPACITY / 4 * 2, buffer.readerIndex());
    }

    @Test
    @SuppressWarnings("deprecation")
    public void testSkipBytes2() {
        buffer.clear();
        buffer.writeZero(buffer.capacity());

        try {
            buffer.skipBytes(ChannelBufferIndexFinder.LF);
            fail();
        } catch (NoSuchElementException e) {
            // Expected
        }

        buffer.skipBytes(ChannelBufferIndexFinder.NUL);
        assertEquals(0, buffer.readerIndex());

        buffer.clear();
        buffer.writeBytes(new byte[] { 1, 2, 3, 4, 0 });
        buffer.skipBytes(ChannelBufferIndexFinder.NUL);
        assertEquals(4, buffer.readerIndex());
    }

    @Test
    public void testHashCode() {
        ChannelBuffer elemA = buffer(15);
        ChannelBuffer elemB = directBuffer(15);
        elemA.writeBytes(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5 });
        elemB.writeBytes(new byte[] { 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 9 });

        Set<ChannelBuffer> set = new HashSet<ChannelBuffer>();
        set.add(elemA);
        set.add(elemB);

        assertEquals(2, set.size());
        assertTrue(set.contains(elemA.copy()));
        assertTrue(set.contains(elemB.copy()));

        buffer.clear();
        buffer.writeBytes(elemA.duplicate());

        assertTrue(set.remove(buffer));
        assertFalse(set.contains(elemA));
        assertEquals(1, set.size());

        buffer.clear();
        buffer.writeBytes(elemB.duplicate());
        assertTrue(set.remove(buffer));
        assertFalse(set.contains(elemB));
        assertEquals(0, set.size());
    }

    // Test case for https://github.com/netty/netty/issues/325
    @Test
    public void testDiscardAllReadBytes() {
        buffer.writerIndex(buffer.capacity());
        buffer.readerIndex(buffer.writerIndex());
        buffer.discardReadBytes();
    }
}
