diff options
Diffstat (limited to 'src/mongo/base/data_range.h')
| -rw-r--r-- | src/mongo/base/data_range.h | 220 |
1 files changed, 107 insertions, 113 deletions
diff --git a/src/mongo/base/data_range.h b/src/mongo/base/data_range.h index 16c7f68ca98..9226e6c133a 100644 --- a/src/mongo/base/data_range.h +++ b/src/mongo/base/data_range.h @@ -39,141 +39,135 @@ namespace mongo { - class ConstDataRange { - - public: - // begin and end should point to the first and one past last bytes in - // the range you wish to view. - // - // debug_offset provides a way to indicate that the ConstDataRange is - // located at an offset into some larger logical buffer. By setting it - // to a non-zero value, you'll change the Status messages that are - // returned on failure to be offset by the amount passed to this - // constructor. - ConstDataRange(const char* begin, const char* end, std::ptrdiff_t debug_offset = 0) - : _begin(begin), _end(end), _debug_offset(debug_offset) { - invariant(end >= begin); - } - - const char* data() const { - return _begin; - } - - size_t length() const { - return _end - _begin; - } +class ConstDataRange { +public: + // begin and end should point to the first and one past last bytes in + // the range you wish to view. + // + // debug_offset provides a way to indicate that the ConstDataRange is + // located at an offset into some larger logical buffer. By setting it + // to a non-zero value, you'll change the Status messages that are + // returned on failure to be offset by the amount passed to this + // constructor. + ConstDataRange(const char* begin, const char* end, std::ptrdiff_t debug_offset = 0) + : _begin(begin), _end(end), _debug_offset(debug_offset) { + invariant(end >= begin); + } + + const char* data() const { + return _begin; + } + + size_t length() const { + return _end - _begin; + } - template<typename T> - Status read(T* t, size_t offset = 0) const { - if (offset > length()) { - return makeOffsetStatus(offset); - } - - return DataType::load(t, _begin + offset, length() - offset, nullptr, - offset + _debug_offset); + template <typename T> + Status read(T* t, size_t offset = 0) const { + if (offset > length()) { + return makeOffsetStatus(offset); } - template<typename T> - StatusWith<T> read(std::size_t offset = 0) const { - T t(DataType::defaultConstruct<T>()); - Status s = read(&t, offset); + return DataType::load( + t, _begin + offset, length() - offset, nullptr, offset + _debug_offset); + } - if (s.isOK()) { - return StatusWith<T>(std::move(t)); - } else { - return StatusWith<T>(std::move(s)); - } - } - - friend bool operator==(const ConstDataRange& lhs, const ConstDataRange& rhs) { - return std::tie(lhs._begin, lhs._end) == std::tie(rhs._begin, rhs._end); + template <typename T> + StatusWith<T> read(std::size_t offset = 0) const { + T t(DataType::defaultConstruct<T>()); + Status s = read(&t, offset); + + if (s.isOK()) { + return StatusWith<T>(std::move(t)); + } else { + return StatusWith<T>(std::move(s)); } + } - friend bool operator!=(const ConstDataRange& lhs, const ConstDataRange& rhs) { - return !(lhs == rhs); - } + friend bool operator==(const ConstDataRange& lhs, const ConstDataRange& rhs) { + return std::tie(lhs._begin, lhs._end) == std::tie(rhs._begin, rhs._end); + } + friend bool operator!=(const ConstDataRange& lhs, const ConstDataRange& rhs) { + return !(lhs == rhs); + } - protected: - const char* _begin; - const char* _end; - std::ptrdiff_t _debug_offset; - Status makeOffsetStatus(size_t offset) const; +protected: + const char* _begin; + const char* _end; + std::ptrdiff_t _debug_offset; - }; + Status makeOffsetStatus(size_t offset) const; +}; - class DataRange : public ConstDataRange { +class DataRange : public ConstDataRange { +public: + typedef char* bytes_type; - public: - typedef char* bytes_type; + DataRange(bytes_type begin, bytes_type end, std::ptrdiff_t debug_offset = 0) + : ConstDataRange(begin, end, debug_offset) {} - DataRange(bytes_type begin, bytes_type end, std::ptrdiff_t debug_offset = 0) - : ConstDataRange(begin, end, debug_offset) { + template <typename T> + Status write(const T& value, std::size_t offset = 0) { + if (offset > length()) { + return makeOffsetStatus(offset); } - template<typename T> - Status write(const T& value, std::size_t offset = 0) { - if (offset > length()) { - return makeOffsetStatus(offset); - } - - return DataType::store(value, const_cast<char *>(_begin + offset), length() - offset, - nullptr, offset + _debug_offset); + return DataType::store(value, + const_cast<char*>(_begin + offset), + length() - offset, + nullptr, + offset + _debug_offset); + } +}; + +struct DataRangeTypeHelper { + static Status makeStoreStatus(size_t t_length, size_t length, std::ptrdiff_t debug_offset); +}; + +// Enable for classes derived from ConstDataRange +template <typename T> +struct DataType::Handler<T, + typename std::enable_if<std::is_base_of<ConstDataRange, T>::value>::type> { + static Status load( + T* t, const char* ptr, size_t length, size_t* advanced, std::ptrdiff_t debug_offset) { + if (t) { + // Assuming you know what you're doing at the read above this + // is fine. Either you're reading into a readable buffer, so + // ptr started off non-const, or the const_cast will feed back + // to const char* taking Const variants. So it'll get tossed + // out again. + *t = T(const_cast<char*>(ptr), const_cast<char*>(ptr) + length); } - }; - - struct DataRangeTypeHelper { - static Status makeStoreStatus(size_t t_length, size_t length, std::ptrdiff_t debug_offset); - }; - - // Enable for classes derived from ConstDataRange - template <typename T> - struct DataType::Handler<T, - typename std::enable_if<std::is_base_of<ConstDataRange, T>::value>::type> { - - static Status load(T* t, const char* ptr, size_t length, size_t* advanced, - std::ptrdiff_t debug_offset) - { - if (t) { - // Assuming you know what you're doing at the read above this - // is fine. Either you're reading into a readable buffer, so - // ptr started off non-const, or the const_cast will feed back - // to const char* taking Const variants. So it'll get tossed - // out again. - *t = T(const_cast<char*>(ptr), const_cast<char*>(ptr) + length); - } - - if (advanced) { - *advanced = length; - } - - return Status::OK(); + if (advanced) { + *advanced = length; } - static Status store(const T& t, char* ptr, size_t length, size_t* advanced, - std::ptrdiff_t debug_offset) - { - if (t.length() > length) { - return DataRangeTypeHelper::makeStoreStatus(t.length(), length, debug_offset); - } - - if (ptr) { - std::memcpy(ptr, t.data(), t.length()); - } + return Status::OK(); + } - if (advanced) { - *advanced = t.length(); - } + static Status store( + const T& t, char* ptr, size_t length, size_t* advanced, std::ptrdiff_t debug_offset) { + if (t.length() > length) { + return DataRangeTypeHelper::makeStoreStatus(t.length(), length, debug_offset); + } - return Status::OK(); + if (ptr) { + std::memcpy(ptr, t.data(), t.length()); } - static T defaultConstruct() - { - return T(nullptr, nullptr); + if (advanced) { + *advanced = t.length(); } - }; -} // namespace mongo + return Status::OK(); + } + + static T defaultConstruct() { + return T(nullptr, nullptr); + } +}; + +} // namespace mongo |