alluxio.worker.block.io.MockBlockWriter.java Source code

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Here is the source code for alluxio.worker.block.io.MockBlockWriter.java

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/*
 * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
 * (the "License"). You may not use this work except in compliance with the License, which is
 * available at www.apache.org/licenses/LICENSE-2.0
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied, as more fully set forth in the License.
 *
 * See the NOTICE file distributed with this work for information regarding copyright ownership.
 */

package alluxio.worker.block.io;

import io.netty.buffer.ByteBuf;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.GatheringByteChannel;
import java.nio.channels.WritableByteChannel;

/**
 * A simple {@link BlockWriter} to use for testing purposes.
 */
public final class MockBlockWriter implements BlockWriter {
    private final ByteArrayOutputStream mOutputStream;
    private long mPosition;

    /**
     * Constructs a mock block writer which will remember all bytes written to it.
     */
    public MockBlockWriter() {
        mOutputStream = new ByteArrayOutputStream();
    }

    @Override
    public void close() throws IOException {
        mOutputStream.close();
        mPosition = -1;
    }

    @Override
    public long append(ByteBuffer inputBuf) throws IOException {
        byte[] bytes = new byte[inputBuf.remaining()];
        inputBuf.get(bytes);
        mOutputStream.write(bytes);
        mPosition += bytes.length;
        return bytes.length;
    }

    @Override
    public void transferFrom(ByteBuf buf) throws IOException {
        mPosition += buf.readBytes(getChannel(), buf.readableBytes());
    }

    @Override
    public GatheringByteChannel getChannel() {
        return new GatheringByteChannel() {
            WritableByteChannel mChannel = Channels.newChannel(mOutputStream);

            @Override
            public long write(ByteBuffer[] srcs, int offset, int length) throws IOException {
                long b = 0;
                for (int i = offset; i < offset + length; i++) {
                    b += mChannel.write(srcs[i]);
                }
                return b;
            }

            @Override
            public long write(ByteBuffer[] srcs) throws IOException {
                return write(srcs, 0, srcs.length);
            }

            @Override
            public int write(ByteBuffer src) throws IOException {
                return mChannel.write(src);
            }

            @Override
            public boolean isOpen() {
                return mChannel.isOpen();
            }

            @Override
            public void close() throws IOException {
                mChannel.close();
            }
        };
    }

    @Override
    public long getPosition() {
        return mPosition;
    }

    /**
     * @return the bytes written to this writer
     */
    public byte[] getBytes() {
        return mOutputStream.toByteArray();
    }
}