NfsWccData.java

/**
 * Copyright 2016-2018 Dell Inc. or its subsidiaries. All rights reserved.
 *
 * <p>Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file
 * except in compliance with the License. A copy of the License is located at
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0.txt
 *
 * <p>or in the "license" file accompanying this file. This file 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 com.emc.ecs.nfsclient.nfs;

import com.emc.ecs.nfsclient.rpc.Xdr;

/**
 * Holder for weak cache consistency data, as specified by RFC 1813
 * (https://tools.ietf.org/html/rfc1813).
 *
 * @author seibed
 */
public class NfsWccData {

  /** Attributes before the operation. */
  private final NfsPreOpAttributes _preOpAttributes;

  /** Attributes after the operation. */
  private final NfsGetAttributes _attributes;

  /** Creates an empty structure. */
  public NfsWccData() {
    this(null);
  }

  /**
   * Creates a structure populated from an Xdr response, as specified by RFC 1813
   * (https://tools.ietf.org/html/rfc1813).
   *
   * @param xdr the response
   */
  public NfsWccData(Xdr xdr) {
    _preOpAttributes = makePreOpAttributes(xdr);
    _attributes = makeAttributes(xdr);
  }

  /** Returns attributes before the operation. */
  public NfsPreOpAttributes getPreOpAttributes() {
    return _preOpAttributes;
  }

  /** Returns attributes after the operation. */
  public NfsGetAttributes getAttributes() {
    return _attributes;
  }

  /**
   * Extracts the pre-operation attributes.
   *
   * @return The attributes.
   */
  private static NfsPreOpAttributes makePreOpAttributes(Xdr xdr) {
    NfsPreOpAttributes preOpAttributes = null;
    if ((xdr != null) && xdr.getBoolean()) {
      preOpAttributes = new NfsPreOpAttributes(xdr);
    }
    return preOpAttributes;
  }

  /**
   * Extracts the post-operation attributes.
   *
   * @return The attributes.
   */
  private static NfsGetAttributes makeAttributes(Xdr xdr) {
    NfsGetAttributes attributes = null;
    if (xdr != null) {
      attributes = NfsResponseBase.makeNfsGetAttributes(xdr);
    }
    return attributes;
  }
}