Nfs3FileHandle.java

/**
 * Copyright 2014 NetApp Inc. All Rights Reserved.
 *
 *  Licensed 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.nfs.nfs3;

import java.nio.ByteBuffer;
import java.util.Arrays;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.oncrpc.XDR;

public class Nfs3FileHandle extends FileHandle {
  
  @SuppressWarnings("unused")
  private static final Log LOG = LogFactory.getLog(Nfs3FileHandle.class);
  private static final String HEXES = "0123456789abcdef";
  private static final int HANDLE_LEN = 32;
  private byte[] handle; // Opaque handle
  private long fileId = -1;

  public Nfs3FileHandle() {
    handle = null;
  }

  public Nfs3FileHandle(long v) {
    fileId = v;
    handle = new byte[HANDLE_LEN];
    handle[0] = (byte)(v >>> 56);
    handle[1] = (byte)(v >>> 48);
    handle[2] = (byte)(v >>> 40);
    handle[3] = (byte)(v >>> 32);
    handle[4] = (byte)(v >>> 24);
    handle[5] = (byte)(v >>> 16);
    handle[6] = (byte)(v >>>  8);
    handle[7] = (byte)(v >>>  0);
    for (int i = 8; i < HANDLE_LEN; i++) {
      handle[i] = (byte) 0;
    }
  }
  
  public Nfs3FileHandle(String s) {
    throw new UnsupportedOperationException("Constructor is only valid for HDFS and this is the NFS driver");
  }
  
  public boolean serialize(XDR out) {
    out.writeInt(handle.length);
    out.writeFixedOpaque(handle);
    return true;
  }

  private long bytesToLong(byte[] data) {
    ByteBuffer buffer = ByteBuffer.allocate(8);
    for (int i = 0; i < 8; i++) {
      buffer.put(data[i]);
    }
    buffer.flip();// need flip
    return buffer.getLong();
  }
  
  public boolean deserialize(XDR xdr) {
    int size = xdr.readInt();
    handle = xdr.readFixedOpaque(size);
    fileId = bytesToLong(handle);
    return true;
  }
  
  private static String hex(byte b) {
    StringBuilder strBuilder = new StringBuilder();
    strBuilder.append(HEXES.charAt((b & 0xF0) >> 4)).append(
        HEXES.charAt((b & 0x0F)));
    return strBuilder.toString();
  }
  
  public long getFileId() {    
    return fileId;
  }
  
  public byte[] getContent() {
    return handle.clone();
  }
  
  @Override
  public String toString() {
    StringBuilder s = new StringBuilder();
    for (int i = 0; i < handle.length; i++) {
      s.append(hex(handle[i]));
    }
    return s.toString();
  }
  
  @Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }

    if (!(o instanceof Nfs3FileHandle)) {
      return false;
    }

    Nfs3FileHandle h = (Nfs3FileHandle) o;
    return Arrays.equals(handle, h.handle);
  }

  @Override
  public int hashCode() {
    return Arrays.hashCode(handle);
  }
}