Dear Qt, I love you but ...

... 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()
qgis · Apr 18, 2019 · 6371151 · 6371151
1 parent 103981d
commit 6371151
Show file tree

Hide file tree

Showing 116 changed files with 21,058 additions and 213 deletions.
diff --git a/external/nlohmann/adl_serializer.hpp b/external/nlohmann/adl_serializer.hpp
@@ -0,0 +1,49 @@
+#pragma once
+
+#include <utility>
+
+#include <nlohmann/detail/conversions/from_json.hpp>
+#include <nlohmann/detail/conversions/to_json.hpp>
+
+namespace nlohmann
+{
+
+template<typename, typename>
+struct adl_serializer
+{
+    /*!
+    @brief convert a JSON value to any value type
+
+    This function is usually called by the `get()` function of the
+    @ref basic_json class (either explicit or via conversion operators).
+
+    @param[in] j        JSON value to read from
+    @param[in,out] val  value to write to
+    */
+    template<typename BasicJsonType, typename ValueType>
+    static auto from_json(BasicJsonType&& j, ValueType& val) noexcept(
+        noexcept(::nlohmann::from_json(std::forward<BasicJsonType>(j), val)))
+    -> decltype(::nlohmann::from_json(std::forward<BasicJsonType>(j), val), void())
+    {
+        ::nlohmann::from_json(std::forward<BasicJsonType>(j), val);
+    }
+
+    /*!
+    @brief convert any value type to a JSON value
+
+    This function is usually called by the constructors of the @ref basic_json
+    class.
+
+    @param[in,out] j  JSON value to write to
+    @param[in] val    value to read from
+    */
+    template <typename BasicJsonType, typename ValueType>
+    static auto to_json(BasicJsonType& j, ValueType&& val) noexcept(
+        noexcept(::nlohmann::to_json(j, std::forward<ValueType>(val))))
+    -> decltype(::nlohmann::to_json(j, std::forward<ValueType>(val)), void())
+    {
+        ::nlohmann::to_json(j, std::forward<ValueType>(val));
+    }
+};
+
+}  // namespace nlohmann