Adding JSON parsing helpers to Utilities.

daggy/CMakeLists.txt

@@ -3,8 +3,8 @@ project(daggy)
 #ExternalProject_Add_StepDependencies(pistache_extern build)
 
 file(GLOB SOURCES src/*.cpp src/**/*.cpp)
-add_library(${PROJECT_NAME} STATIC ${SOURCES} src/Scheduler.cpp)
+add_library(${PROJECT_NAME} STATIC ${SOURCES})
 include_directories(${PISTACHE_INCLUDE_DIR})
 target_include_directories(${PROJECT_NAME} PUBLIC include)
 target_link_libraries(${PROJECT_NAME} pistache pthread)
-add_dependencies(${PROJECT_NAME} PistacheDownload)
+add_dependencies(${PROJECT_NAME} PistacheDownload rapidjson)

daggy/include/daggy/Utilities.hpp

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <vector>
+#include <string>
+#include <variant>
+#include <unordered_map>
+
+#include <rapidjson/document.h>
+
+#include "Task.hpp"
+
+namespace rj = rapidjson;
+
+namespace daggy {
+    using ParameterValue = std::variant<std::string, std::vector<std::string>>;
+    using ParameterValues = std::unordered_map<std::string, ParameterValue>;
+
+    ParameterValues parseParameters(const std::string & jsonSpec);
+    ParameterValues parseParameters(const rj::Document & spec);
+    // std::vector<Task> buildTasks(const std::string & jsonSpec, const ParameterValues & parameters);
+    // std::vector<Task> buildTasks(const rj::Document & spec, const ParameterValues & parameters);
+}

daggy/src/Utilities.cpp

@@ -0,0 +1,67 @@
+#include <daggy/Utilities.hpp>
+
+namespace daggy {
+    ParameterValues parseParameters(const std::string & jsonSpec) {
+        rj::Document doc;
+        rj::ParseResult parseResult = doc.Parse(jsonSpec.c_str());
+        if (! parseResult) {
+            throw std::runtime_error("Parameters spec is not valid JSON");
+        }
+        return parseParameters(doc);
+    }
+
+    ParameterValues parseParameters(const rj::Document & spec) {
+        std::unordered_map<std::string, ParameterValue> parameters;
+        if (!spec.IsObject()) { throw std::runtime_error("Parameters in spec is not a JSON dictionary"); }
+        for (auto it = spec.MemberBegin(); it != spec.MemberEnd(); ++it) {
+            if (! it->name.IsString()) {
+                throw std::runtime_error("All keys must be strings.");
+            }
+            if (it->value.IsArray()) {
+                std::vector<std::string> values;
+                for (size_t i = 0; i < it->value.Size(); ++i) {
+                    if (! it->value[i].IsString()) {
+                        throw std::runtime_error("Attribute for " + std::string{it->name.GetString()} + " item " + std::to_string(i) + " is not a string.");
+                    }
+                    values.emplace_back(it->value[i].GetString());
+                }
+                parameters[it->name.GetString()] = values;
+            } else if (it->value.IsString()) {
+                parameters[it->name.GetString()] = it->value.GetString();
+            } else {
+                throw std::runtime_error("Attribute for " + std::string{it->name.GetString()} + " is not a string or an array.");
+            }
+        }
+        return parameters;
+    }
+
+    /*
+    std::vector<Task> buildTasks(const std::string & jsonSpec) {
+        rj::Document doc;
+        rj::ParseResult parseResult = doc.Parse(jsonSpec.c_str());
+        if (! parseResult) {
+            throw std::runtime_error("Unable to parse spec: ");
+        }
+        return buildTasks(doc);
+    }
+
+    std::vector<Task> buildTasks(const rj::Document & spec) {
+        std::vector<Task> tasks;
+        if (!spec.IsObject()) { throw std::runtime_error("Spec is not a JSON dictionary"); }
+
+        // Parameter Parsing
+        auto parameters = parseParameters(spec);
+        // Tasks
+        if (spec.HasMember("tasks")) {
+            auto & sTasks = spec["tasks"];
+            if (! sTasks.IsArray()) {
+                throw std::runtime_error("tasks member must be an array");
+            }
+            for (size_t i = 0; i < sTasks.Size(); ++i) {
+                tasks.push_back(parseTask(sTasks[i]));
+            }
+        }
+        return tasks;
+    }
+    */
+}