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This module contains all API code for Apache Fluo. External dependencies should be limited. Any changes to public methods should be avoided. While the API module does not have compile time dependency on fluo-core, you must include fluo-core as a run-time dependency.

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/*
 * 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.fluo.api.data;

import java.io.Serializable;
import java.util.Objects;

/**
 * Represents all or subset of a Fluo row and {@link Column}. RowColumn is similar to an Accumulo
 * Key. RowColumn is immutable after it is created.
 *
 * @since 1.0.0
 */
public final class RowColumn implements Comparable, Serializable {

  private static final long serialVersionUID = 1L;
  public static RowColumn EMPTY = new RowColumn();

  private Bytes row = Bytes.EMPTY;
  private Column col = Column.EMPTY;

  /**
   * Constructs a RowColumn with row set to Bytes.EMPTY and column set to Column.EMPTY
   */
  public RowColumn() {}

  /**
   * Constructs a RowColumn with only a row. Column will be set to Column.EMPTY
   *
   * @param row Bytes Row
   */
  public RowColumn(Bytes row) {
    Objects.requireNonNull(row, "Row must not be null");
    this.row = row;
  }

  /**
   * Constructs a RowColumn with only a row. Column will be set to Column.EMPTY
   *
   * @param row (will be UTF-8 encoded)
   */
  public RowColumn(CharSequence row) {
    this(Bytes.of(row));
  }

  /**
   * Constructs a RowColumn
   *
   * @param row Bytes Row
   * @param col Column
   */
  public RowColumn(Bytes row, Column col) {
    Objects.requireNonNull(row, "Row must not be null");
    Objects.requireNonNull(col, "Col must not be null");
    this.row = row;
    this.col = col;
  }

  /**
   * Constructs a RowColumn
   *
   * @param row Row String (will be UTF-8 encoded)
   * @param col Column
   */
  public RowColumn(CharSequence row, Column col) {
    this(Bytes.of(row), col);
  }

  /**
   * Retrieves Row in RowColumn
   *
   * @return Row
   */
  public Bytes getRow() {
    return row;
  }

  /**
   * Retrieves Row in RowColumn as a String using UTF-8 encoding.
   *
   * @return Row
   */
  public String getsRow() {
    return row.toString();
  }

  /**
   * Retrieves Column in RowColumn
   *
   * @return Column
   */
  public Column getColumn() {
    return col;
  }

  @Override
  public String toString() {
    return row + " " + col;
  }

  @Override
  public boolean equals(Object o) {
    if (o instanceof RowColumn) {
      RowColumn other = (RowColumn) o;
      return row.equals(other.row) && col.equals(other.col);
    }
    return false;
  }

  @Override
  public int hashCode() {
    return Objects.hash(row, col);
  }

  /**
   * Returns a RowColumn following the current one
   *
   * @return RowColumn following this one
   */
  public RowColumn following() {
    if (row.equals(Bytes.EMPTY)) {
      return RowColumn.EMPTY;
    } else if (col.equals(Column.EMPTY)) {
      return new RowColumn(followingBytes(row));
    } else if (!col.isQualifierSet()) {
      return new RowColumn(row, new Column(followingBytes(col.getFamily())));
    } else if (!col.isVisibilitySet()) {
      return new RowColumn(row, new Column(col.getFamily(), followingBytes(col.getQualifier())));
    } else {
      return new RowColumn(row, new Column(col.getFamily(), col.getQualifier(),
          followingBytes(col.getVisibility())));
    }
  }

  private byte[] followingArray(byte[] ba) {
    byte[] fba = new byte[ba.length + 1];
    System.arraycopy(ba, 0, fba, 0, ba.length);
    fba[ba.length] = (byte) 0x00;
    return fba;
  }

  private Bytes followingBytes(Bytes b) {
    return Bytes.of(followingArray(b.toArray()));
  }

  @Override
  public int compareTo(RowColumn other) {
    int result = row.compareTo(other.row);
    if (result == 0) {
      result = col.compareTo(other.col);
    }
    return result;
  }
}