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The modules contains the core implementation code of Fluo.
There is a newer version: 1.0.0-beta-2
/*
 * Copyright 2014 Fluo authors (see AUTHORS)
 *
 * 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 io.fluo.core.util;

import io.fluo.api.data.Bytes;
import io.fluo.api.data.Column;
import io.fluo.api.data.RowColumn;
import io.fluo.api.data.Span;
import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Range;
import org.apache.hadoop.io.Text;

/**
 * Utility methods for manipulating Spans
 */
public class SpanUtil {
  
  private SpanUtil() {}
  
  /**
   * Converts a Fluo Span to Accumulo Range
   * 
   * @param span Span
   * @return Range
   */
  public static Range toRange(Span span) {
    return new Range(toKey(span.getStart()), span.isStartInclusive(), toKey(span.getEnd()), span.isEndInclusive());
  }
  
  /**
   * Converts from a Fluo RowColumn to a Accumulo Key
   * 
   * @param rc RowColumn
   * @return Key
   */
  public static Key toKey(RowColumn rc) {
    if ((rc == null) || (rc.getRow().equals(Bytes.EMPTY))) {
      return null;
    }
    Text row = ByteUtil.toText(rc.getRow());
    if ((rc.getColumn().equals(Column.EMPTY)) || (rc.getColumn().getFamily().equals(Bytes.EMPTY))) {
      return new Key(row);
    }
    Text cf = ByteUtil.toText(rc.getColumn().getFamily());
    if (rc.getColumn().getQualifier().equals(Bytes.EMPTY)) {
      return new Key(row, cf);
    }
    Text cq = ByteUtil.toText(rc.getColumn().getQualifier());
    if (rc.getColumn().getVisibility().equals(Bytes.EMPTY)) {
      return new Key(row, cf, cq);
    }
    Text cv = ByteUtil.toText(rc.getColumn().getVisibility());
    return new Key(row, cf, cq, cv);
  }
  
  /**
   * Converts an Accumulo Range to a Fluo Span
   * 
   * @param range Range
   * @return Span
   */
  public static Span toSpan(Range range) {
    return new Span(toRowColumn(range.getStartKey()), range.isStartKeyInclusive(), 
                    toRowColumn(range.getEndKey()), range.isEndKeyInclusive());
  }
  
  /**
   * Converts from an Accumulo Key to a Fluo RowColumn
   * 
   * @param key Key
   * @return RowColumn
   */
  public static RowColumn toRowColumn(Key key) {
    if (key == null) {
      return RowColumn.EMPTY;
    }
    if ((key.getRow() == null) || key.getRow().getLength() == 0) {
      return RowColumn.EMPTY;
    }
    Bytes row = ByteUtil.toBytes(key.getRow());
    if ((key.getColumnFamily() == null) || key.getColumnFamily().getLength() == 0) {
      return new RowColumn(row);
    }
    Bytes cf = ByteUtil.toBytes(key.getColumnFamily());
    if ((key.getColumnQualifier() == null) || key.getColumnQualifier().getLength() == 0) {
      return new RowColumn(row, new Column(cf));
    }
    Bytes cq = ByteUtil.toBytes(key.getColumnQualifier());
    if ((key.getColumnVisibility() == null) || key.getColumnVisibility().getLength() == 0) {
      return new RowColumn(row, new Column(cf, cq));
    }
    Bytes cv = ByteUtil.toBytes(key.getColumnVisibility());
    return new RowColumn(row, new Column(cf, cq, cv));
  }
}