src/base/digest32.h

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2015, 2021  Vladimir Golovnev <glassez@yandex.ru>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  *
  19  * In addition, as a special exception, the copyright holders give permission to
  20  * link this program with the OpenSSL project's "OpenSSL" library (or with
  21  * modified versions of it that use the same license as the "OpenSSL" library),
  22  * and distribute the linked executables. You must obey the GNU General Public
  23  * License in all respects for all of the code used other than "OpenSSL".  If you
  24  * modify file(s), you may extend this exception to your version of the file(s),
  25  * but you are not obligated to do so. If you do not wish to do so, delete this
  26  * exception statement from your version.
  27  */
  28
  29 #pragma once
  30
  31 #include <libtorrent/sha1_hash.hpp>
  32
  33 #include <QtGlobal>
  34 #include <QByteArray>
  35 #include <QHash>
  36 #include <QSharedData>
  37 #include <QSharedDataPointer>
  38 #include <QString>
  39
  40 template <int N>
  41 class Digest32
  42 {
  43 public:
  44     using UnderlyingType = lt::digest32<N>;
  45
  46     Digest32() = default;
  47     Digest32(const Digest32 &other) = default;
  48     Digest32(Digest32 &&other) = default;
  49
  50     Digest32(const UnderlyingType &nativeDigest)
  51         : m_dataPtr {new Data(nativeDigest)}
  52     {
  53     }
  54
  55     static constexpr int length()
  56     {
  57         return UnderlyingType::size();
  58     }
  59
  60     bool isValid() const
  61     {
  62         return m_dataPtr->isValid();
  63     }
  64
  65     Digest32 &operator=(const Digest32 &other) = default;
  66     Digest32 &operator=(Digest32 &&other) = default;
  67
  68     operator UnderlyingType() const
  69     {
  70         return m_dataPtr->nativeDigest();
  71     }
  72
  73     QString toString() const
  74     {
  75         return m_dataPtr->hashString();
  76     }
  77
  78     static Digest32 fromString(const QString &digestString)
  79     {
  80         return Digest32(QSharedDataPointer<Data>(new Data(digestString)));
  81     }
  82
  83 private:
  84     class Data;
  85
  86     explicit Digest32(QSharedDataPointer<Data> dataPtr)
  87         : m_dataPtr {dataPtr}
  88     {
  89     }
  90
  91     QSharedDataPointer<Data> m_dataPtr {new Data};
  92 };
  93
  94 template <int N>
  95 class Digest32<N>::Data : public QSharedData
  96 {
  97 public:
  98     Data() = default;
  99
 100     explicit Data(UnderlyingType nativeDigest)
 101         : m_isValid {true}
 102         , m_nativeDigest {nativeDigest}
 103     {
 104     }
 105
 106     explicit Data(const QString &digestString)
 107     {
 108         if (digestString.size() != (length() * 2))
 109             return;
 110
 111         const QByteArray raw = QByteArray::fromHex(digestString.toLatin1());
 112         if (raw.size() != length())  // QByteArray::fromHex() will skip over invalid characters
 113             return;
 114
 115         m_isValid = true;
 116         m_hashString = digestString;
 117         m_nativeDigest.assign(raw.constData());
 118     }
 119
 120     bool isValid() const { return m_isValid; }
 121     UnderlyingType nativeDigest() const { return m_nativeDigest; }
 122
 123     QString hashString() const
 124     {
 125         if (m_hashString.isEmpty())
 126         {
 127             const QByteArray raw = QByteArray::fromRawData(m_nativeDigest.data(), length());
 128             m_hashString = QString::fromLatin1(raw.toHex());
 129         }
 130
 131         return m_hashString;
 132     }
 133
 134 private:
 135     bool m_isValid = false;
 136     UnderlyingType m_nativeDigest;
 137     mutable QString m_hashString;
 138 };
 139
 140 template <int N>
 141 bool operator==(const Digest32<N> &left, const Digest32<N> &right)
 142 {
 143     return (static_cast<typename Digest32<N>::UnderlyingType>(left)
 144             == static_cast<typename Digest32<N>::UnderlyingType>(right));
 145 }
 146
 147 template <int N>
 148 bool operator!=(const Digest32<N> &left, const Digest32<N> &right)
 149 {
 150     return !(left == right);
 151 }
 152
 153 template <int N>
 154 bool operator<(const Digest32<N> &left, const Digest32<N> &right)
 155 {
 156     return static_cast<typename Digest32<N>::UnderlyingType>(left)
 157             < static_cast<typename Digest32<N>::UnderlyingType>(right);
 158 }
 159
 160 #if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
 161 template <int N>
 162 std::size_t qHash(const Digest32<N> &key, const std::size_t seed = 0)
 163 {
 164     return ::qHash(static_cast<typename Digest32<N>::UnderlyingType>(key), seed);
 165 }
 166 #else
 167 template <int N>
 168 uint qHash(const Digest32<N> &key, const uint seed = 0)
 169 {
 170     return static_cast<uint>((std::hash<typename Digest32<N>::UnderlyingType> {})(key)) ^ seed;
 171 }
 172 #endif