add extension: header only json config

CMakeLists.txt

@@ -240,6 +240,8 @@ if(GINKGO_BUILD_TESTS)
 endif()
 if(GINKGO_BUILD_BENCHMARKS)
     find_package(gflags 2.2.2 QUIET)
+endif()
+if(GINKGO_BUILD_TESTS OR GINKGO_BUILD_BENCHMARKS)
     find_package(nlohmann_json 3.9.1 QUIET)
 endif()
 

extensions/test/CMakeLists.txt

@@ -4,3 +4,5 @@ find_package(Kokkos 4.1.00 QUIET)
 if (Kokkos_FOUND)
     add_subdirectory(kokkos)
 endif ()
+
+add_subdirectory(config)

extensions/test/config/CMakeLists.txt

@@ -0,0 +1,2 @@
+ginkgo_create_test(json_config ADDITIONAL_LIBRARIES nlohmann_json::nlohmann_json)
+configure_file("test.json" test.json COPYONLY)

extensions/test/config/json_config.cpp

@@ -0,0 +1,79 @@
+// SPDX-FileCopyrightText: 2017 - 2024 The Ginkgo authors
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include <gtest/gtest.h>
+#include <nlohmann/json.hpp>
+
+
+#include <ginkgo/core/config/property_tree.hpp>
+#include <ginkgo/extensions/config/json_config.hpp>
+
+
+#include "core/test/utils.hpp"
+
+
+TEST(JsonConfig, ReadMap)
+{
+    const char json[] = R"({"test": "A", "bool": true})";
+    auto d = nlohmann::json::parse(json);
+
+    auto ptree = gko::ext::config::parse_json(d);
+
+    ASSERT_EQ(ptree.get_map().size(), 2);
+    ASSERT_EQ(ptree.get("test").get_string(), "A");
+    ASSERT_EQ(ptree.get("bool").get_boolean(), true);
+}
+
+
+TEST(JsonConfig, ReadArray)
+{
+    const char json[] = R"(["A", "B", "C"])";
+    auto d = nlohmann::json::parse(json);
+
+    auto ptree = gko::ext::config::parse_json(d);
+
+    ASSERT_EQ(ptree.get_array().size(), 3);
+    ASSERT_EQ(ptree.get(0).get_string(), "A");
+    ASSERT_EQ(ptree.get(1).get_string(), "B");
+    ASSERT_EQ(ptree.get(2).get_string(), "C");
+}
+
+
+TEST(JsonConfig, ReadInput)
+{
+    const char json[] =
+        R"({"item": 4,
+            "array": [3.0, 4.5], 
+            "map": {"bool": false}})";
+
+    auto d = nlohmann::json::parse(json);
+
+    auto ptree = gko::ext::config::parse_json(d);
+
+    auto& child_array = ptree.get("array").get_array();
+    auto& child_map = ptree.get("map").get_map();
+    ASSERT_EQ(ptree.get_map().size(), 3);
+    ASSERT_EQ(ptree.get("item").get_integer(), 4);
+    ASSERT_EQ(child_array.size(), 2);
+    ASSERT_EQ(child_array.at(0).get_real(), 3.0);
+    ASSERT_EQ(child_array.at(1).get_real(), 4.5);
+    ASSERT_EQ(child_map.size(), 1);
+    ASSERT_EQ(child_map.at("bool").get_boolean(), false);
+}
+
+
+TEST(JsonConfig, ReadInputFromFile)
+{
+    auto ptree = gko::ext::config::parse_json_file("test.json");
+
+    auto& child_array = ptree.get("array").get_array();
+    auto& child_map = ptree.get("map").get_map();
+    ASSERT_EQ(ptree.get_map().size(), 3);
+    ASSERT_EQ(ptree.get("item").get_integer(), 4);
+    ASSERT_EQ(child_array.size(), 2);
+    ASSERT_EQ(child_array.at(0).get_real(), 3.0);
+    ASSERT_EQ(child_array.at(1).get_real(), 4.5);
+    ASSERT_EQ(child_map.size(), 1);
+    ASSERT_EQ(child_map.at("bool").get_boolean(), false);
+}

extensions/test/config/test.json

@@ -0,0 +1,10 @@
+{
+    "item": 4,
+    "array": [
+        3.0,
+        4.5
+    ],
+    "map": {
+        "bool": false
+    }
+}

include/ginkgo/extensions/config/json_config.hpp

@@ -0,0 +1,88 @@
+// SPDX-FileCopyrightText: 2017 - 2024 The Ginkgo authors
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#ifndef GKO_PUBLIC_EXTENSIONS_CONFIG_JSON_CONFIG_HPP_
+#define GKO_PUBLIC_EXTENSIONS_CONFIG_JSON_CONFIG_HPP_
+
+
+#include <fstream>
+#include <string>
+
+
+#include <nlohmann/json.hpp>
+
+
+#include <ginkgo/core/config/property_tree.hpp>
+
+
+namespace gko {
+namespace ext {
+namespace config {
+
+
+/**
+ * parse_json takes the nlohmann json object to generate the property tree
+ * object
+ */
+inline gko::config::pnode parse_json(const nlohmann::json& input)
+{
+    const auto& dom = input;
+
+    auto parse_array = [](const auto& arr) {
+        gko::config::pnode::array_type nodes;
+        for (auto it : arr) {
+            nodes.emplace_back(parse_json(it));
+        }
+        return gko::config::pnode{nodes};
+    };
+    auto parse_map = [](const auto& map) {
+        gko::config::pnode::map_type nodes;
+        for (auto& el : map.items()) {
+            nodes.emplace(el.key(), parse_json(el.value()));
+        }
+        return gko::config::pnode{nodes};
+    };
+    auto parse_data = [](const auto& data) {
+        if (data.is_number_integer()) {
+            return gko::config::pnode{data.template get<std::int64_t>()};
+        }
+        if (data.is_boolean()) {
+            return gko::config::pnode{data.template get<bool>()};
+        }
+        if (data.is_number_float()) {
+            return gko::config::pnode{data.template get<double>()};
+        }
+        if (data.is_string()) {
+            return gko::config::pnode{
+                std::string(data.template get<std::string>())};
+        }
+        return gko::config::pnode{};
+    };
+
+    if (dom.is_array()) {
+        return parse_array(dom);
+    }
+    if (dom.is_object()) {
+        return parse_map(dom);
+    }
+    return parse_data(dom);
+}
+
+
+/**
+ * parse_json_file takes the json file to generate the property tree object
+ */
+inline gko::config::pnode parse_json_file(std::string filename)
+{
+    std::ifstream fstream(filename);
+    return parse_json(nlohmann::json::parse(fstream));
+}
+
+
+}  // namespace config
+}  // namespace ext
+}  // namespace gko
+
+
+#endif  // GKO_PUBLIC_EXTENSIONS_CONFIG_JSON_CONFIG_HPP_

third_party/CMakeLists.txt

@@ -11,6 +11,9 @@ if(GINKGO_BUILD_BENCHMARKS)
     if (NOT gflags_FOUND)
         add_subdirectory(gflags)
     endif()
+endif()
+
+if(GINKGO_BUILD_TESTS OR GINKGO_BUILD_BENCHMARKS)
     if (NOT nlohmann_json_FOUND)
         add_subdirectory(nlohmann_json)
     endif()