server/base/src/main/java/org/apache/accumulo/server/fs/FileRef.java

/*
 * 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.accumulo.server.fs;

import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.server.fs.VolumeManager.FileType;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;

/**
 * This is a glue object, to convert short file references to long references. The metadata may
 * contain old relative file references. This class keeps track of the short file reference, so it
 * can be removed properly from the metadata tables.
 */
public class FileRef implements Comparable<FileRef> {
  private String metaReference; // something like ../2/d-00000/A00001.rf
  private Path fullReference; // something like hdfs://nn:9001/accumulo/tables/2/d-00000/A00001.rf
  private Path suffix;

  public FileRef(VolumeManager fs, Key key) {
    this(key.getColumnQualifier().toString(), fs.getFullPath(key));
  }

  public FileRef(String metaReference, Path fullReference) {
    this.metaReference = metaReference;
    this.fullReference = fullReference;
    this.suffix = extractSuffix(fullReference);
  }

  public FileRef(String path) {
    this(path, new Path(path));
  }

  @Override
  public String toString() {
    return fullReference.toString();
  }

  public Path path() {
    return fullReference;
  }

  public Text meta() {
    return new Text(metaReference);
  }

  static Path extractSuffix(Path path) {
    String pstr = path.toString();
    int index = pstr.lastIndexOf(FileType.TABLE.getDirectory());
    if (index < 0)
      throw new IllegalArgumentException("Invalid table path " + pstr);

    try {
      Path parent = path.getParent().getParent();
      if (!parent.getName().equals(FileType.TABLE.getDirectory())
          && !parent.getParent().getName().equals(FileType.TABLE.getDirectory()))
        throw new IllegalArgumentException("Invalid table path " + pstr);
    } catch (NullPointerException npe) {
      throw new IllegalArgumentException("Invalid table path " + pstr);
    }

    return new Path(pstr.substring(index + FileType.TABLE.getDirectory().length() + 1));
  }

  @Override
  public int compareTo(FileRef o) {
    return suffix.compareTo(o.suffix);
  }

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

  @Override
  public boolean equals(Object obj) {
    if (obj instanceof FileRef) {
      return compareTo((FileRef) obj) == 0;
    }
    return false;
  }

}