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63711510b6
... you are too slow and QJson API is so ugly. Now using this wonderful json lib: https://github.com/nlohmann/json Results in release mode (QJson tests are not shown but QJson was even slower than string concat). PASS : TestQgsJsonUtils::testExportAttributesJson(Use json) RESULT : TestQgsJsonUtils::testExportAttributesJson():"Use json": 0.0022 msecs per iteration (total: 75, iterations: 32768) PASS : TestQgsJsonUtils::testExportAttributesJson(Use old string concat) RESULT : TestQgsJsonUtils::testExportAttributesJson():"Use old string concat": 0.0032 msecs per iteration (total: 54, iterations: 16384) PASS : TestQgsJsonUtils::testExportFeatureJson(Use json) RESULT : TestQgsJsonUtils::testExportFeatureJson():"Use json": 0.011 msecs per iteration (total: 96, iterations: 8192) PASS : TestQgsJsonUtils::testExportFeatureJson(Use old string concat) RESULT : TestQgsJsonUtils::testExportFeatureJson():"Use old string concat": 0.015 msecs per iteration (total: 64, iterations: 4096) PASS : TestQgsJsonUtils::testExportGeomToJson(Use json) RESULT : TestQgsJsonUtils::testExportGeomToJson():"Use json": 0.76 msecs per iteration (total: 98, iterations: 128) PASS : TestQgsJsonUtils::testExportGeomToJson(Use old string concat) RESULT : TestQgsJsonUtils::testExportGeomToJson():"Use old string concat": 0.85 msecs per iteration (total: 55, iterations: 64) PASS : TestQgsJsonUtils::cleanupTestCase()
121 lines
2.7 KiB
C++
121 lines
2.7 KiB
C++
#pragma once
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#include <cstddef> // ptrdiff_t
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#include <limits> // numeric_limits
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namespace nlohmann
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{
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namespace detail
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{
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/*
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@brief an iterator for primitive JSON types
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This class models an iterator for primitive JSON types (boolean, number,
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string). It's only purpose is to allow the iterator/const_iterator classes
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to "iterate" over primitive values. Internally, the iterator is modeled by
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a `difference_type` variable. Value begin_value (`0`) models the begin,
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end_value (`1`) models past the end.
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*/
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class primitive_iterator_t
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{
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private:
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using difference_type = std::ptrdiff_t;
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static constexpr difference_type begin_value = 0;
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static constexpr difference_type end_value = begin_value + 1;
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/// iterator as signed integer type
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difference_type m_it = (std::numeric_limits<std::ptrdiff_t>::min)();
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public:
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constexpr difference_type get_value() const noexcept
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{
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return m_it;
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}
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/// set iterator to a defined beginning
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void set_begin() noexcept
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{
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m_it = begin_value;
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}
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/// set iterator to a defined past the end
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void set_end() noexcept
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{
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m_it = end_value;
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}
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/// return whether the iterator can be dereferenced
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constexpr bool is_begin() const noexcept
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{
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return m_it == begin_value;
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}
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/// return whether the iterator is at end
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constexpr bool is_end() const noexcept
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{
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return m_it == end_value;
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}
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friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
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{
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return lhs.m_it == rhs.m_it;
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}
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friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
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{
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return lhs.m_it < rhs.m_it;
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}
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primitive_iterator_t operator+(difference_type n) noexcept
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{
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auto result = *this;
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result += n;
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return result;
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}
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friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
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{
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return lhs.m_it - rhs.m_it;
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}
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primitive_iterator_t& operator++() noexcept
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{
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++m_it;
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return *this;
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}
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primitive_iterator_t const operator++(int) noexcept
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{
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auto result = *this;
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++m_it;
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return result;
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}
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primitive_iterator_t& operator--() noexcept
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{
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--m_it;
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return *this;
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}
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primitive_iterator_t const operator--(int) noexcept
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{
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auto result = *this;
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--m_it;
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return result;
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}
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primitive_iterator_t& operator+=(difference_type n) noexcept
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{
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m_it += n;
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return *this;
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}
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primitive_iterator_t& operator-=(difference_type n) noexcept
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{
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m_it -= n;
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return *this;
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}
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};
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} // namespace detail
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} // namespace nlohmann
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