IHashAlgorithm.h

// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2026 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
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/* IHashAlgorithm.h                                            (C) 2000-2023 */
/*                                                                           */
/* Interface of a hashing algorithm.                                         */
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#ifndef ARCANE_UTILS_IHASHALGORITHM_H
#define ARCANE_UTILS_IHASHALGORITHM_H
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#include "arcane/utils/UtilsTypes.h"
 
#include "arccore/base/Span.h"
#include "arccore/base/RefDeclarations.h"
 
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namespace Arcane
{
 
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class ARCANE_UTILS_EXPORT HashAlgorithmValue
{
 public:
 
  static constexpr Int32 MAX_SIZE = 64;
 
 public:
 
  SmallSpan<std::byte> bytes()
  {
    return { m_value.data(), m_size };
  }
  SmallSpan<const std::byte> bytes() const
  {
    return { m_value.data(), m_size };
  }
  SmallSpan<const Byte> asLegacyBytes() const
  {
    return { reinterpret_cast<const Byte*>(m_value.data()), m_size };
  }
  void setSize(Int32 size);
 
 private:
 
  std::array<std::byte, MAX_SIZE> m_value = {};
  Int32 m_size = MAX_SIZE;
};
 
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class ARCANE_UTILS_EXPORT IHashAlgorithmContext
{
 public:
 
  virtual ~IHashAlgorithmContext() = default;
 
 public:

  virtual void reset() = 0;

  virtual void updateHash(Span<const std::byte> input) = 0;

  virtual void computeHashValue(HashAlgorithmValue& hash_value) = 0;
};
 
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class ARCANE_UTILS_EXPORT IHashAlgorithm
{
 public:
 
  virtual ~IHashAlgorithm() = default;
 
 public:
 
  //NOTE: for now (version 3.10) still pure virtual to remain
  // compatible with existing code
  virtual String name() const;
 
  //NOTE: for now (version 3.10) still pure virtual to remain
  // compatible with existing code. Throws FatalErrorException if not overridden
  virtual Int32 hashSize() const;

  virtual void computeHash64(Span<const Byte> input, ByteArray& output);

  virtual void computeHash64(Span<const std::byte> input, ByteArray& output);
 
  //NOTE: for now (version 3.10) still pure virtual to remain
  // compatible with existing code
  virtual void computeHash(Span<const std::byte> input, HashAlgorithmValue& value);
 
  //NOTE: for now (version 3.11) still pure virtual to remain
  // compatible with existing code
  virtual Ref<IHashAlgorithmContext> createContext();
 
  //NOTE: for now (version 3.11) still pure virtual to remain
  // compatible with existing code
  virtual bool hasCreateContext() const { return false; }
 
 public:

  ARCANE_DEPRECATED_REASON("Y2023: Use computeHash64(Span<const std::byte> input,ByteArray& output) instead")
  virtual void computeHash(ByteConstArrayView input, ByteArray& output) = 0;
};
 
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} // namespace Arcane
 
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#endif