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()
 
@@ -265,6 +267,11 @@ endif()
 # Bundled third party libraries
 add_subdirectory(third_party)    # Third-party tools and libraries
 
+if(GINKGO_BUILD_TESTS)
+    # Non core directories and targets
+    add_subdirectory(extensions)
+endif()
+
 if(MSVC)
     if(BUILD_SHARED_LIBS)
         set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS TRUE)
@@ -312,8 +319,6 @@ if(GINKGO_BUILD_TESTS)
     add_subdirectory(test)       # Tests running on all executors
 endif()
 
-# Non core directories and targets
-add_subdirectory(extensions)
 
 if(GINKGO_BUILD_EXAMPLES)
     add_subdirectory(examples)

extensions/test/CMakeLists.txt

@@ -5,7 +5,4 @@ if (Kokkos_FOUND)
     add_subdirectory(kokkos)
 endif ()
 
-find_package(nlohmann_json 3.9.1 QUIET)
-if (nlohmann_json_FOUND)
-    add_subdirectory(config)
-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

@@ -20,6 +20,11 @@ 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;
@@ -65,6 +70,9 @@ inline gko::config::pnode parse_json(const nlohmann::json& input)
 }
 
 
+/**
+ * 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);

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()