digest.hpp

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
#ifndef NDN_UTIL_DIGEST_HPP
#define NDN_UTIL_DIGEST_HPP

#include "../encoding/buffer.hpp"
#include "../encoding/block.hpp"
#include "../security/cryptopp.hpp"
#include "concepts.hpp"

namespace ndn {
namespace util {

template<typename Hash>
class Digest
{
public:
  BOOST_CONCEPT_ASSERT((Hashable<Hash>));

  typedef Hash HashFunction;

  class Error : public std::runtime_error
  {
  public:
    explicit
    Error(const std::string& what)
      : std::runtime_error(what)
    {
    }
  };

  Digest();

  explicit
  Digest(std::istream& is);

  void
  reset();

  bool
  empty() const
  {
    return !m_isInProcess;
  }

  ConstBufferPtr
  computeDigest();

  bool
  operator==(Digest<Hash>& digest);

  bool
  operator!=(Digest<Hash>& digest)
  {
    return !(*this == digest);
  }

  Digest<Hash>&
  operator<<(Digest<Hash>& src);

  Digest<Hash>&
  operator<<(const std::string& str);

  Digest<Hash>&
  operator<<(const Block& block);

  Digest<Hash>&
  operator<<(uint64_t value);

  void
  update(const uint8_t* buffer, size_t size);

  static ConstBufferPtr
  computeDigest(const uint8_t* buffer, size_t size);

  std::string
  toString();

private:
  void
  finalize();

private:
  Hash m_hash;
  BufferPtr m_buffer;
  bool m_isInProcess;
  bool m_isFinalized;
};

template<typename Hash>
std::ostream&
operator<<(std::ostream& os, Digest<Hash>& digest);

typedef Digest<CryptoPP::SHA256> Sha256;

} // namespace util
} // namespace ndn

#endif // NDN_UTIL_DIGEST_HPP