Java example source code file (FixedCompositeByteBuf.java)

This example Java source code file (FixedCompositeByteBuf.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytebuf, bytebufallocator, bytebuffer, byteorder, component, empty, filechannel, fixedcompositebytebuf, ioexception, nio, object, override, readonlybufferexception, string, unsupportedoperationexception, util

The FixedCompositeByteBuf.java Java example source code

/*
 * Copyright 2013 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 io.netty.buffer;

import io.netty.util.internal.EmptyArrays;
import io.netty.util.internal.RecyclableArrayList;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.ReadOnlyBufferException;
import java.nio.channels.FileChannel;
import java.nio.channels.GatheringByteChannel;
import java.nio.channels.ScatteringByteChannel;
import java.util.Collections;

/**
 * {@link ByteBuf} implementation which allows to wrap an array of {@link ByteBuf} in a read-only mode.
 * This is useful to write an array of {@link ByteBuf}s.
 */
final class FixedCompositeByteBuf extends AbstractReferenceCountedByteBuf {
    private static final ByteBuf[] EMPTY = { Unpooled.EMPTY_BUFFER };
    private final int nioBufferCount;
    private final int capacity;
    private final ByteBufAllocator allocator;
    private final ByteOrder order;
    private final Object[] buffers;
    private final boolean direct;

    FixedCompositeByteBuf(ByteBufAllocator allocator, ByteBuf... buffers) {
        super(Integer.MAX_VALUE);
        if (buffers.length == 0) {
            this.buffers = EMPTY;
            order = ByteOrder.BIG_ENDIAN;
            nioBufferCount = 1;
            capacity = 0;
            direct = false;
        } else {
            ByteBuf b = buffers[0];
            this.buffers = new Object[buffers.length];
            this.buffers[0] = b;
            boolean direct = true;
            int nioBufferCount = b.nioBufferCount();
            int capacity = b.readableBytes();
            order = b.order();
            for (int i = 1; i < buffers.length; i++) {
                b = buffers[i];
                if (buffers[i].order() != order) {
                    throw new IllegalArgumentException("All ByteBufs need to have same ByteOrder");
                }
                nioBufferCount += b.nioBufferCount();
                capacity += b.readableBytes();
                if (!b.isDirect()) {
                    direct = false;
                }
                this.buffers[i] = b;
            }
            this.nioBufferCount = nioBufferCount;
            this.capacity = capacity;
            this.direct = direct;
        }
        setIndex(0, capacity());
        this.allocator = allocator;
    }

    @Override
    public boolean isWritable() {
        return false;
    }

    @Override
    public boolean isWritable(int size) {
        return false;
    }

    @Override
    public ByteBuf discardReadBytes() {
        throw new ReadOnlyBufferException();
    }

    @Override
    public ByteBuf setBytes(int index, ByteBuf src, int srcIndex, int length) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public ByteBuf setBytes(int index, byte[] src, int srcIndex, int length) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public ByteBuf setBytes(int index, ByteBuffer src) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public ByteBuf setByte(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    protected void _setByte(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public ByteBuf setShort(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    protected void _setShort(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    protected void _setShortLE(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public ByteBuf setMedium(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    protected void _setMedium(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    protected void _setMediumLE(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public ByteBuf setInt(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    protected void _setInt(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    protected void _setIntLE(int index, int value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public ByteBuf setLong(int index, long value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    protected void _setLong(int index, long value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    protected void _setLongLE(int index, long value) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public int setBytes(int index, InputStream in, int length) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public int setBytes(int index, ScatteringByteChannel in, int length) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public int setBytes(int index, FileChannel in, long position, int length) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public int capacity() {
        return capacity;
    }

    @Override
    public int maxCapacity() {
        return capacity;
    }

    @Override
    public ByteBuf capacity(int newCapacity) {
        throw new ReadOnlyBufferException();
    }

    @Override
    public ByteBufAllocator alloc() {
        return allocator;
    }

    @Override
    public ByteOrder order() {
        return order;
    }

    @Override
    public ByteBuf unwrap() {
        return null;
    }

    @Override
    public boolean isDirect() {
        return direct;
    }

    private Component findComponent(int index) {
        int readable = 0;
        for (int i = 0 ; i < buffers.length; i++) {
            Component comp = null;
            ByteBuf b;
            Object obj = buffers[i];
            boolean isBuffer;
            if (obj instanceof ByteBuf) {
                b = (ByteBuf) obj;
                isBuffer = true;
            } else {
                comp = (Component) obj;
                b = comp.buf;
                isBuffer = false;
            }
            readable += b.readableBytes();
            if (index < readable) {
                if (isBuffer) {
                    // Create a new component ad store ti in the array so it not create a new object
                    // on the next access.
                    comp = new Component(i, readable - b.readableBytes(), b);
                    buffers[i] = comp;
                }
                return comp;
            }
        }
        throw new IllegalStateException();
    }

    /**
     * Return the {@link ByteBuf} stored at the given index of the array.
     */
    private ByteBuf buffer(int i) {
        Object obj = buffers[i];
        if (obj instanceof ByteBuf) {
            return (ByteBuf) obj;
        }
        return ((Component) obj).buf;
    }

    @Override
    public byte getByte(int index) {
        return _getByte(index);
    }

    @Override
    protected byte _getByte(int index) {
        Component c = findComponent(index);
        return c.buf.getByte(index - c.offset);
    }

    @Override
    protected short _getShort(int index) {
        Component c = findComponent(index);
        if (index + 2 <= c.endOffset) {
            return c.buf.getShort(index - c.offset);
        } else if (order() == ByteOrder.BIG_ENDIAN) {
            return (short) ((_getByte(index) & 0xff) << 8 | _getByte(index + 1) & 0xff);
        } else {
            return (short) (_getByte(index) & 0xff | (_getByte(index + 1) & 0xff) << 8);
        }
    }

    @Override
    protected short _getShortLE(int index) {
        Component c = findComponent(index);
        if (index + 2 <= c.endOffset) {
            return c.buf.getShortLE(index - c.offset);
        } else if (order() == ByteOrder.BIG_ENDIAN) {
            return (short) (_getByte(index) & 0xff | (_getByte(index + 1) & 0xff) << 8);
        } else {
            return (short) ((_getByte(index) & 0xff) << 8 | _getByte(index + 1) & 0xff);
        }
    }

    @Override
    protected int _getUnsignedMedium(int index) {
        Component c = findComponent(index);
        if (index + 3 <= c.endOffset) {
            return c.buf.getUnsignedMedium(index - c.offset);
        } else if (order() == ByteOrder.BIG_ENDIAN) {
            return (_getShort(index) & 0xffff) << 8 | _getByte(index + 2) & 0xff;
        } else {
            return _getShort(index) & 0xFFFF | (_getByte(index + 2) & 0xFF) << 16;
        }
    }

    @Override
    protected int _getUnsignedMediumLE(int index) {
        Component c = findComponent(index);
        if (index + 3 <= c.endOffset) {
            return c.buf.getUnsignedMediumLE(index - c.offset);
        } else if (order() == ByteOrder.BIG_ENDIAN) {
            return _getShortLE(index) & 0xffff | (_getByte(index + 2) & 0xff) << 16;
        } else {
            return (_getShortLE(index) & 0xffff) << 8 | _getByte(index + 2) & 0xff;
        }
    }

    @Override
    protected int _getInt(int index) {
        Component c = findComponent(index);
        if (index + 4 <= c.endOffset) {
            return c.buf.getInt(index - c.offset);
        } else if (order() == ByteOrder.BIG_ENDIAN) {
            return (_getShort(index) & 0xffff) << 16 | _getShort(index + 2) & 0xffff;
        } else {
            return _getShort(index) & 0xFFFF | (_getShort(index + 2) & 0xFFFF) << 16;
        }
    }

    @Override
    protected int _getIntLE(int index) {
        Component c = findComponent(index);
        if (index + 4 <= c.endOffset) {
            return c.buf.getIntLE(index - c.offset);
        } else if (order() == ByteOrder.BIG_ENDIAN) {
            return _getShortLE(index) & 0xFFFF | (_getShortLE(index + 2) & 0xFFFF) << 16;
        } else {
            return (_getShortLE(index) & 0xffff) << 16 | _getShortLE(index + 2) & 0xffff;
        }
    }

    @Override
    protected long _getLong(int index) {
        Component c = findComponent(index);
        if (index + 8 <= c.endOffset) {
            return c.buf.getLong(index - c.offset);
        } else if (order() == ByteOrder.BIG_ENDIAN) {
            return (_getInt(index) & 0xffffffffL) << 32 | _getInt(index + 4) & 0xffffffffL;
        } else {
            return _getInt(index) & 0xFFFFFFFFL | (_getInt(index + 4) & 0xFFFFFFFFL) << 32;
        }
    }

    @Override
    protected long _getLongLE(int index) {
        Component c = findComponent(index);
        if (index + 8 <= c.endOffset) {
            return c.buf.getLongLE(index - c.offset);
        } else if (order() == ByteOrder.BIG_ENDIAN) {
            return _getIntLE(index) & 0xffffffffL | (_getIntLE(index + 4) & 0xffffffffL) << 32;
        } else {
            return (_getIntLE(index) & 0xffffffffL) << 32 | _getIntLE(index + 4) & 0xffffffffL;
        }
    }

    @Override
    public ByteBuf getBytes(int index, byte[] dst, int dstIndex, int length) {
        checkDstIndex(index, length, dstIndex, dst.length);
        if (length == 0) {
            return this;
        }

        Component c = findComponent(index);
        int i = c.index;
        int adjustment = c.offset;
        ByteBuf s = c.buf;
        for (;;) {
            int localLength = Math.min(length, s.readableBytes() - (index - adjustment));
            s.getBytes(index - adjustment, dst, dstIndex, localLength);
            index += localLength;
            dstIndex += localLength;
            length -= localLength;
            adjustment += s.readableBytes();
            if (length <= 0) {
                break;
            }
            s = buffer(++i);
        }
        return this;
    }

    @Override
    public ByteBuf getBytes(int index, ByteBuffer dst) {
        int limit = dst.limit();
        int length = dst.remaining();

        checkIndex(index, length);
        if (length == 0) {
            return this;
        }

        try {
            Component c = findComponent(index);
            int i = c.index;
            int adjustment = c.offset;
            ByteBuf s = c.buf;
            for (;;) {
                int localLength = Math.min(length, s.readableBytes() - (index - adjustment));
                dst.limit(dst.position() + localLength);
                s.getBytes(index - adjustment, dst);
                index += localLength;
                length -= localLength;
                adjustment += s.readableBytes();
                if (length <= 0) {
                    break;
                }
                s = buffer(++i);
            }
        } finally {
            dst.limit(limit);
        }
        return this;
    }

    @Override
    public ByteBuf getBytes(int index, ByteBuf dst, int dstIndex, int length) {
        checkDstIndex(index, length, dstIndex, dst.capacity());
        if (length == 0) {
            return this;
        }

        Component c = findComponent(index);
        int i = c.index;
        int adjustment = c.offset;
        ByteBuf s = c.buf;
        for (;;) {
            int localLength = Math.min(length, s.readableBytes() - (index - adjustment));
            s.getBytes(index - adjustment, dst, dstIndex, localLength);
            index += localLength;
            dstIndex += localLength;
            length -= localLength;
            adjustment += s.readableBytes();
            if (length <= 0) {
                break;
            }
            s = buffer(++i);
        }
        return this;
    }

    @Override
    public int getBytes(int index, GatheringByteChannel out, int length)
            throws IOException {
        int count = nioBufferCount();
        if (count == 1) {
            return out.write(internalNioBuffer(index, length));
        } else {
            long writtenBytes = out.write(nioBuffers(index, length));
            if (writtenBytes > Integer.MAX_VALUE) {
                return Integer.MAX_VALUE;
            } else {
                return (int) writtenBytes;
            }
        }
    }

    @Override
    public int getBytes(int index, FileChannel out, long position, int length)
            throws IOException {
        int count = nioBufferCount();
        if (count == 1) {
            return out.write(internalNioBuffer(index, length), position);
        } else {
            long writtenBytes = 0;
            for (ByteBuffer buf : nioBuffers(index, length)) {
                writtenBytes += out.write(buf, position + writtenBytes);
            }
            if (writtenBytes > Integer.MAX_VALUE) {
                return Integer.MAX_VALUE;
            } else {
                return (int) writtenBytes;
            }
        }
    }

    @Override
    public ByteBuf getBytes(int index, OutputStream out, int length) throws IOException {
        checkIndex(index, length);
        if (length == 0) {
            return this;
        }

        Component c = findComponent(index);
        int i = c.index;
        int adjustment = c.offset;
        ByteBuf s = c.buf;
        for (;;) {
            int localLength = Math.min(length, s.readableBytes() - (index - adjustment));
            s.getBytes(index - adjustment, out, localLength);
            index += localLength;
            length -= localLength;
            adjustment += s.readableBytes();
            if (length <= 0) {
                break;
            }
            s = buffer(++i);
        }
        return this;
    }

    @Override
    public ByteBuf copy(int index, int length) {
        checkIndex(index, length);
        boolean release = true;
        ByteBuf buf = alloc().buffer(length);
        try {
            buf.writeBytes(this, index, length);
            release = false;
            return buf;
        } finally {
            if (release) {
                buf.release();
            }
        }
    }

    @Override
    public int nioBufferCount() {
        return nioBufferCount;
    }

    @Override
    public ByteBuffer nioBuffer(int index, int length) {
        checkIndex(index, length);
        if (buffers.length == 1) {
            ByteBuf buf = buffer(0);
            if (buf.nioBufferCount() == 1) {
                return buf.nioBuffer(index, length);
            }
        }
        ByteBuffer merged = ByteBuffer.allocate(length).order(order());
        ByteBuffer[] buffers = nioBuffers(index, length);

        //noinspection ForLoopReplaceableByForEach
        for (int i = 0; i < buffers.length; i++) {
            merged.put(buffers[i]);
        }

        merged.flip();
        return merged;
    }

    @Override
    public ByteBuffer internalNioBuffer(int index, int length) {
        if (buffers.length == 1) {
            return buffer(0).internalNioBuffer(index, length);
        }
        throw new UnsupportedOperationException();
    }

    @Override
    public ByteBuffer[] nioBuffers(int index, int length) {
        checkIndex(index, length);
        if (length == 0) {
            return EmptyArrays.EMPTY_BYTE_BUFFERS;
        }

        RecyclableArrayList array = RecyclableArrayList.newInstance(buffers.length);
        try {
            Component c = findComponent(index);
            int i = c.index;
            int adjustment = c.offset;
            ByteBuf s = c.buf;
            for (;;) {
                int localLength = Math.min(length, s.readableBytes() - (index - adjustment));
                switch (s.nioBufferCount()) {
                    case 0:
                        throw new UnsupportedOperationException();
                    case 1:
                        array.add(s.nioBuffer(index - adjustment, localLength));
                        break;
                    default:
                        Collections.addAll(array, s.nioBuffers(index - adjustment, localLength));
                }

                index += localLength;
                length -= localLength;
                adjustment += s.readableBytes();
                if (length <= 0) {
                    break;
                }
                s = buffer(++i);
            }

            return array.toArray(new ByteBuffer[array.size()]);
        } finally {
            array.recycle();
        }
    }

    @Override
    public boolean hasArray() {
        return false;
    }

    @Override
    public byte[] array() {
        throw new UnsupportedOperationException();
    }

    @Override
    public int arrayOffset() {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean hasMemoryAddress() {
        return false;
    }

    @Override
    public long memoryAddress() {
        throw new UnsupportedOperationException();
    }

    @Override
    protected void deallocate() {
        for (int i = 0; i < buffers.length; i++) {
             buffer(i).release();
        }
    }

    @Override
    public String toString() {
        String result = super.toString();
        result = result.substring(0, result.length() - 1);
        return result + ", components=" + buffers.length + ')';
    }

    private static final class Component {
        private final int index;
        private final int offset;
        private final ByteBuf buf;
        private final int endOffset;

        Component(int index, int offset, ByteBuf buf) {
            this.index = index;
            this.offset = offset;
            endOffset = offset + buf.readableBytes();
            this.buf = buf;
        }
    }
}