content: /*
   * 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.client.file.cache;
  
  import com.google.common.base.MoreObjects;
  import com.google.common.base.Objects;
  
  import javax.annotation.concurrent.ThreadSafe;
  
  /**
   * A class identifies a single cached page.
   */
  @ThreadSafe
  public class PageId {
    private final String mFileId;
    private final long mPageIndex;
  
    /**
     * @param fileId file Id
     * @param pageIndex index of the page in file
     */
    public PageId(String fileId, long pageIndex) {
      mFileId = fileId;
      mPageIndex = pageIndex;
    }
  
    /**
     * @return file id
     */
    public String getFileId() {
      return mFileId;
    }
  
    /**
     * @return index of the page in file
     */
    public long getPageIndex() {
      return mPageIndex;
    }
  
    @Override
    public int hashCode() {
      return Objects.hashCode(mFileId, mPageIndex);
    }
  
    @Override
    public boolean equals(Object obj) {
      if (this == obj) {
        return true;
      }
      if (!(obj instanceof PageId)) {
        return false;
      }
      PageId that = (PageId) obj;
      return mFileId.equals(that.mFileId) && mPageIndex == that.mPageIndex;
    }
  
    @Override
    public String toString() {
      return MoreObjects.toStringHelper(this)
          .add("FileId", mFileId)
          .add("PageIndex", mPageIndex)
          .toString();
    }
  }
  