SSL

^© Kompilation durch diese Firma

[Weder Korrektheit noch Funktionsfähigkeit der Software werden zugesichert.]

sichere Verbindung decoder.cpp Sprache: C

/*
* Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* 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_UTILITIES_TRIBOOL_HPP
#define SHARE_UTILITIES_TRIBOOL_HPP

#include "utilities/globalDefinitions.hpp"

// 2-bit boolean type: H|L
// the high-bit H is set if it's not default value.
// the low-bit L represents true and false.
class TriBool{
  template <size_t SZ, typename T>
  friend class TriBoolArray;

private:
  unsigned int _value : 2;
  explicit TriBool(u1 raw) : _value(raw & 3) {}

public:
  TriBool() : _value(0) {}
  TriBool(bool value) : _value(((u1)value) | 2) {}
  TriBool(const TriBool& o): _value(o._value) {}

  TriBool& operator=(bool value) {
    _value = ((u1)value) | 2;
    return *this;
  }

  TriBool& operator=(const TriBool& o) {
    _value = o._value;
    return *this;
  }

  bool is_default() const {
    return !static_cast<bool>(_value >> 1);
  }

  /*explicit*/ operator bool() const {
    return (_value & 1);
  }
};

// compacted array of TriBool
template <size_t SZ, typename T>
class TriBoolArray {
private:
  class TriBoolAssigner : public TriBool {
   public:
    TriBoolAssigner(T& slot, size_t offset) : TriBool(static_cast<u1>(slot >> offset)),
                                              _slot(slot), _offset(offset) {}

    TriBoolAssigner& operator=(bool newval) {
      _slot ^= ((u1)_value) << _offset;  // reset the tribool
      _value = (u1)newval| 2;
      _slot |= ((u1)_value) << _offset;
      return *this;
    };

    TriBoolAssigner& operator=(TriBool tb) {
      _slot ^= ((u1)_value) << _offset;  // reset the tribool
      _value = (u1)tb._value;
      _slot |= ((u1)_value) << _offset;
      return *this;
    }

   private:
    T& _slot;
    size_t _offset;
  };

public:
  TriBoolArray() {}

  TriBoolArray(const TriBool& init) {
    fill_in(init);
  }

  TriBool operator[](size_t x) const {
    size_t index = x / (_slot_size);
    size_t offset = x % (_slot_size);
    T raw = (_array[index] >> (2 * offset)) & 3;
    return TriBool(static_cast<u1>(raw));
  }

  TriBoolAssigner operator[](size_t x) {
    size_t index = x / (_slot_size);
    size_t offset = x % (_slot_size);
    return TriBoolAssigner(_array[index], 2 * offset);
  }

  void fill_in(const TriBool& val) {
      if (val.is_default()) {
        memset(_array, 0, _size * sizeof(T));
      }
      else {
        for (size_t i = 0; i < SZ; ++i) {
          (*this)[i] = val;
        }
      }
  }

  void fill_in(const TriBool* beg, const TriBool* end) {
      size_t i = 0;

      while (i < SZ && beg != end) {
        (*this)[i++] = *beg++;
      }
  }

private:
  const static size_t _bits_in_T = sizeof(T) * 8;   // bits in a byte
  const static size_t _slot_size = _bits_in_T >> 1; // one TriBool occupies 2bits
  const static size_t _size = (2 * SZ + _bits_in_T - 1) / (_bits_in_T);
  T _array[_size];
};

#endif // SHARE_UTILITIES_TRIBOOL_HPP

¤ Dauer der Verarbeitung: 0.17 Sekunden (vorverarbeitet) ¤

Druckansicht unsichere Verbindung
Druckansicht sprechenden Kalenders
in der Quellcodebibliothek suchen

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.

SSL