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/*
 * Copyright 2015-16, Yahoo! Inc.
 * Licensed under the terms of the Apache License 2.0. See LICENSE file at the project root for terms.
 */

package com.yahoo.sketches.tuple;

/**
 * Top level compact tuple sketch of type ArrayOfDoubles. Compact sketches are never created 
 * directly.  They are created as a result of the compact() method on a QuickSelectSketch
 * or the getResult() method of a set operation like Union, Intersection or AnotB.
 * Compact sketch consists of a compact list (i.e. no intervening spaces) of hash values,
 * corresponding list of double values, and a value for theta. The lists may or may
 * not be ordered. A compact sketch is read-only.
 */
public abstract class ArrayOfDoublesCompactSketch extends ArrayOfDoublesSketch {

  static final byte serialVersionUID = 1;

  // Layout of retained entries:
  // Long || Start Byte Adr:
  // Adr: 
  //      ||   23   |   22   |   21   |   20   |   19   |   18   |   17   |    16     |
  //  3   ||-----------------------------------|----------Retained Entries------------|

  static final int EMPTY_SIZE = 16;
  static final int RETAINED_ENTRIES_INT = 16;
  // 4 bytes of padding for 8 byte alignment
  static final int ENTRIES_START = 24;

  ArrayOfDoublesCompactSketch(final int numValues) {
    super(numValues);
  }
}