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| |
| #ifndef QBYTEARRAYMATCHER_H |
| #define QBYTEARRAYMATCHER_H |
| |
| #include <QtCore/qbytearray.h> |
| |
| QT_BEGIN_NAMESPACE |
| |
| |
| class QByteArrayMatcherPrivate; |
| |
| class Q_CORE_EXPORT QByteArrayMatcher |
| { |
| public: |
| QByteArrayMatcher(); |
| explicit QByteArrayMatcher(const QByteArray &pattern); |
| explicit QByteArrayMatcher(const char *pattern, int length); |
| QByteArrayMatcher(const QByteArrayMatcher &other); |
| ~QByteArrayMatcher(); |
| |
| QByteArrayMatcher &operator=(const QByteArrayMatcher &other); |
| |
| void setPattern(const QByteArray &pattern); |
| |
| int indexIn(const QByteArray &ba, int from = 0) const; |
| int indexIn(const char *str, int len, int from = 0) const; |
| inline QByteArray pattern() const |
| { |
| if (q_pattern.isNull()) |
| return QByteArray(reinterpret_cast<const char*>(p.p), p.l); |
| return q_pattern; |
| } |
| |
| private: |
| QByteArrayMatcherPrivate *d; |
| QByteArray q_pattern; |
| struct Data { |
| uchar q_skiptable[256]; |
| const uchar *p; |
| int l; |
| }; |
| union { |
| uint dummy[256]; |
| Data p; |
| }; |
| }; |
| |
| class QStaticByteArrayMatcherBase |
| { |
| Q_DECL_ALIGN(16) |
| struct Skiptable { |
| uchar data[256]; |
| } m_skiptable; |
| protected: |
| explicit Q_DECL_RELAXED_CONSTEXPR QStaticByteArrayMatcherBase(const char *pattern, uint n) noexcept |
| : m_skiptable(generate(pattern, n)) {} |
| // compiler-generated copy/more ctors/assignment operators are ok! |
| // compiler-generated dtor is ok! |
| |
| Q_CORE_EXPORT int indexOfIn(const char *needle, uint nlen, const char *haystack, int hlen, int from) const noexcept; |
| |
| private: |
| static Q_DECL_RELAXED_CONSTEXPR Skiptable generate(const char *pattern, uint n) noexcept |
| { |
| const auto uchar_max = (std::numeric_limits<uchar>::max)(); |
| uchar max = n > uchar_max ? uchar_max : n; |
| Skiptable table = { |
| // this verbose initialization code aims to avoid some opaque error messages |
| // even on powerful compilers such as GCC 5.3. Even though for GCC a loop |
| // format can be found that v5.3 groks, it's probably better to go with this |
| // for the time being: |
| { |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, max, |
| } |
| }; |
| pattern += n - max; |
| while (max--) |
| table.data[uchar(*pattern++)] = max; |
| return table; |
| } |
| }; |
| |
| template <uint N> |
| class QStaticByteArrayMatcher : QStaticByteArrayMatcherBase |
| { |
| char m_pattern[N]; |
| Q_STATIC_ASSERT_X(N > 2, "QStaticByteArrayMatcher makes no sense for finding a single-char pattern"); |
| public: |
| explicit Q_DECL_RELAXED_CONSTEXPR QStaticByteArrayMatcher(const char (&patternToMatch)[N]) noexcept |
| : QStaticByteArrayMatcherBase(patternToMatch, N - 1), m_pattern() |
| { |
| for (uint i = 0; i < N; ++i) |
| m_pattern[i] = patternToMatch[i]; |
| } |
| |
| int indexIn(const QByteArray &haystack, int from = 0) const noexcept |
| { return this->indexOfIn(m_pattern, N - 1, haystack.data(), haystack.size(), from); } |
| int indexIn(const char *haystack, int hlen, int from = 0) const noexcept |
| { return this->indexOfIn(m_pattern, N - 1, haystack, hlen, from); } |
| |
| QByteArray pattern() const { return QByteArray(m_pattern, int(N - 1)); } |
| }; |
| |
| template <uint N> |
| Q_DECL_RELAXED_CONSTEXPR QStaticByteArrayMatcher<N> qMakeStaticByteArrayMatcher(const char (&pattern)[N]) noexcept |
| { return QStaticByteArrayMatcher<N>(pattern); } |
| |
| QT_END_NAMESPACE |
| |
| #endif // QBYTEARRAYMATCHER_H |