/*

 * Copyright (c) 2018, Red Hat, Inc. All rights reserved.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHNUMBERSEQ_HPP

#define SHARE_VM_GC_SHENANDOAH_SHENANDOAHNUMBERSEQ_HPP

#include "utilities/numberSeq.hpp"

// HDR sequence stores the low-resolution high-dynamic-range values.

// It does so by maintaining the double array, where first array defines

// the magnitude of the value being stored, and the second array maintains

// the low resolution histogram within that magnitude. For example, storing

// 4.352819 * 10^3 increments the bucket _hdr[3][435]. This allows for

// memory efficient storage of huge amount of samples.

//

// Accepts positive numbers only.

class HdrSeq: public NumberSeq {

private:

  enum PrivateConstants {

    ValBuckets = 512,

    MagBuckets = 24,

    MagMinimum = -12,

  };

  int** _hdr;

public:

  HdrSeq();

  ~HdrSeq();

  virtual void add(double val);

  double percentile(double level) const;

};

// Binary magnitude sequence stores the power-of-two histogram.

// It has very low memory requirements, and is thread-safe. When accuracy

// is not needed, it is preferred over HdrSeq.

class BinaryMagnitudeSeq {

private:

  size_t  _sum;

  size_t* _mags;

public:

  BinaryMagnitudeSeq();

  ~BinaryMagnitudeSeq();

  void add(size_t val);

  size_t num() const;

  size_t level(int level) const;

  size_t sum() const;

  int min_level() const;

  int max_level() const;

};

#endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHNUMBERSEQ_HPP