org.apache.hadoop.io.DataInputByteBuffer.java Source code

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Here is the source code for org.apache.hadoop.io.DataInputByteBuffer.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hadoop.io;

import java.io.DataInputStream;
import java.io.InputStream;
import java.nio.ByteBuffer;

public class DataInputByteBuffer extends DataInputStream {

    private static class Buffer extends InputStream {
        private final byte[] scratch = new byte[1];
        ByteBuffer[] buffers = new ByteBuffer[0];
        int bidx, pos, length;

        @Override
        public int read() {
            if (-1 == read(scratch, 0, 1)) {
                return -1;
            }
            return scratch[0] & 0xFF;
        }

        @Override
        public int read(byte[] b, int off, int len) {
            if (bidx >= buffers.length) {
                return -1;
            }
            int cur = 0;
            do {
                int rem = Math.min(len, buffers[bidx].remaining());
                buffers[bidx].get(b, off, rem);
                cur += rem;
                off += rem;
                len -= rem;
            } while (len > 0 && ++bidx < buffers.length);
            pos += cur;
            return cur;
        }

        public void reset(ByteBuffer[] buffers) {
            bidx = pos = length = 0;
            this.buffers = buffers;
            for (ByteBuffer b : buffers) {
                length += b.remaining();
            }
        }

        public int getPosition() {
            return pos;
        }

        public int getLength() {
            return length;
        }

        public ByteBuffer[] getData() {
            return buffers;
        }
    }

    private Buffer buffers;

    public DataInputByteBuffer() {
        this(new Buffer());
    }

    private DataInputByteBuffer(Buffer buffers) {
        super(buffers);
        this.buffers = buffers;
    }

    public void reset(ByteBuffer... input) {
        buffers.reset(input);
    }

    public ByteBuffer[] getData() {
        return buffers.getData();
    }

    public int getPosition() {
        return buffers.getPosition();
    }

    public int getLength() {
        return buffers.getLength();
    }
}