modules/nio/src/main/java/common/java/nio/ReadWriteDirectByteBuffer.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 java.nio;

import org.apache.harmony.luni.platform.PlatformAddress;

/**
 * DirectByteBuffer, ReadWriteDirectByteBuffer and ReadOnlyDirectByteBuffer
 * compose the implementation of platform memory based byte buffers.
 * <p>
 * ReadWriteDirectByteBuffer extends DirectByteBuffer with all the write
 * methods.
 * </p>
 * <p>
 * This class is marked final for runtime performance.
 * </p>
 * 
 */
final class ReadWriteDirectByteBuffer extends DirectByteBuffer {

    static ReadWriteDirectByteBuffer copy(DirectByteBuffer other,
            int markOfOther) {
        ReadWriteDirectByteBuffer buf = new ReadWriteDirectByteBuffer(
                other.address, other.capacity(), other.offset);
        buf.limit = other.limit();
        buf.position = other.position();
        buf.mark = markOfOther;
        buf.order(other.order());
        return buf;
    }

    ReadWriteDirectByteBuffer(int capacity) {
        super(capacity);
    }

    ReadWriteDirectByteBuffer(PlatformAddress address, int capacity, int offset) {
        super(address, capacity, offset);
    }

    @Override
    public ByteBuffer asReadOnlyBuffer() {
        return ReadOnlyDirectByteBuffer.copy(this, mark);
    }

    @Override
    public ByteBuffer compact() {
        PlatformAddress effectiveAddress = getEffectiveAddress();
        effectiveAddress.offsetBytes(position).moveTo(effectiveAddress,
                remaining());
        position = limit - position;
        limit = capacity;
        mark = UNSET_MARK;
        return this;
    }

    @Override
    public ByteBuffer duplicate() {
        return copy(this, mark);
    }

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

    @Override
    public ByteBuffer put(byte value) {
        if (position == limit) {
            throw new BufferOverflowException();
        }
        getBaseAddress().setByte(offset + position++, value);
        return this;
    }

    @Override
    public ByteBuffer put(int index, byte value) {
        if (index < 0 || index >= limit) {
            throw new IndexOutOfBoundsException();
        }
        getBaseAddress().setByte(offset + index, value);
        return this;
    }

    /*
     * Override ByteBuffer.put(byte[], int, int) to improve performance.
     * 
     * (non-Javadoc)
     * 
     * @see java.nio.ByteBuffer#put(byte[], int, int)
     */
    @Override
    public ByteBuffer put(byte[] src, int off, int len) {
        int length = src.length;
        if (off < 0 || len < 0 || (long) off + (long) len > length) {
            throw new IndexOutOfBoundsException();
        }
        if (len > remaining()) {
            throw new BufferOverflowException();
        }
        getBaseAddress().setByteArray(offset + position, src, off, len);
        position += len;
        return this;
    }

    @Override
    public ByteBuffer putDouble(double value) {
        int newPosition = position + 8;
        if (newPosition > limit) {
            throw new BufferOverflowException();
        }
        getBaseAddress().setDouble(offset + position, value, order);
        position = newPosition;
        return this;
    }

    @Override
    public ByteBuffer putDouble(int index, double value) {
        if (index < 0 || (long) index + 8 > limit) {
            throw new IndexOutOfBoundsException();
        }
        getBaseAddress().setDouble(offset + index, value, order);
        return this;
    }

    @Override
    public ByteBuffer putFloat(float value) {
        int newPosition = position + 4;
        if (newPosition > limit) {
            throw new BufferOverflowException();
        }
        getBaseAddress().setFloat(offset + position, value, order);
        position = newPosition;
        return this;
    }

    @Override
    public ByteBuffer putFloat(int index, float value) {
        if (index < 0 || (long) index + 4 > limit) {
            throw new IndexOutOfBoundsException();
        }
        getBaseAddress().setFloat(offset + index, value, order);
        return this;
    }

    @Override
    public ByteBuffer putInt(int value) {
        int newPosition = position + 4;
        if (newPosition > limit) {
            throw new BufferOverflowException();
        }
        getBaseAddress().setInt(offset + position, value, order);
        position = newPosition;
        return this;
    }

    @Override
    public ByteBuffer putInt(int index, int value) {
        if (index < 0 || (long) index + 4 > limit) {
            throw new IndexOutOfBoundsException();
        }
        getBaseAddress().setInt(offset + index, value, order);
        return this;
    }

    @Override
    public ByteBuffer putLong(long value) {
        int newPosition = position + 8;
        if (newPosition > limit) {
            throw new BufferOverflowException();
        }
        getBaseAddress().setLong(offset + position, value, order);
        position = newPosition;
        return this;
    }

    @Override
    public ByteBuffer putLong(int index, long value) {
        if (index < 0 || (long) index + 8 > limit) {
            throw new IndexOutOfBoundsException();
        }
        getBaseAddress().setLong(offset + index, value, order);
        return this;
    }

    @Override
    public ByteBuffer putShort(short value) {
        int newPosition = position + 2;
        if (newPosition > limit) {
            throw new BufferOverflowException();
        }
        getBaseAddress().setShort(offset + position, value, order);
        position = newPosition;
        return this;
    }

    @Override
    public ByteBuffer putShort(int index, short value) {
        if (index < 0 || (long) index + 2 > limit) {
            throw new IndexOutOfBoundsException();
        }
        getBaseAddress().setShort(offset + index, value, order);
        return this;
    }

    @Override
    public ByteBuffer slice() {
        ReadWriteDirectByteBuffer buf = new ReadWriteDirectByteBuffer(
                address, remaining(), offset + position);
        buf.order = order;
        return buf;
    }

}