Data base class

src/CMakeLists.txt

@@ -110,6 +110,7 @@ set (HEADER_FILES
         modules/interp_met
 		modules/snobal
 		modules/testing
+        modules/submodules
 		math
         libmaw
         interpolation
@@ -412,17 +413,18 @@ if (BUILD_TESTS)
 	message(STATUS "Tests enabled. Run with make check")
 
 	set(TEST_SRCS
-			tests/test_station.cpp
-			tests/test_interpolation.cpp
-			tests/test_timeseries.cpp
-			tests/test_core.cpp
-			tests/test_variablestorage.cpp
-			tests/test_metdata.cpp
-			tests/test_netcdf.cpp
+        #tests/test_station.cpp
+        #	tests/test_interpolation.cpp
+        #		tests/test_timeseries.cpp
+        #	tests/test_core.cpp
+        #	tests/test_variablestorage.cpp
+        #	tests/test_metdata.cpp
+        #	tests/test_netcdf.cpp
 			#    test_mesh.cpp
 			tests/test_regexptokenizer.cpp
 			#    test_daily.cpp
-            tests/test_triangulation.cpp
+            #     tests/test_triangulation.cpp
+            tests/submoduletests/test_data_base.cpp
 			tests/main.cpp
     )
 

src/mesh/triangulation.hpp

@@ -436,9 +436,10 @@ class face : public Fb
 
 //    void set_module_data(const std::string &module, face_info *fi);
 
-    template<typename T>
-    T& make_module_data(const std::string &module);
-
+    // Overload for module data constructor
+    template<typename T, typename... Args>
+    T& make_module_data(const std::string &module, Args... args);
+
     std::string _debug_name; //for debugging to find the elem that we want
     int _debug_ID; //also for debugging. ID == the position in the output order, starting at 0
     size_t cell_global_id;
@@ -1788,22 +1789,22 @@ timeseries::iterator face<Gt, Fb>::now()
 }
 
 
+// Overloaded for construtor that requires arguments
 template < class Gt, class Vb>
-template<typename T>
-T& face<Gt, Vb>::make_module_data(const std::string &module)
+template<typename T, typename... Args>
+T& face<Gt, Vb>::make_module_data(const std::string &module, Args... args)
 {
 
     //we don't already have this, make a new one.
     if(!_module_face_data[module])
     {
 //        T* data = new T;
-        _module_face_data[module] = std::make_unique<T>();
+        _module_face_data[module] = std::make_unique<T>(args...);
     }
 
     return get_module_data<T&>(module);
 }
 
-
 template < class Gt, class Fb>
 template < typename T>
 T& face<Gt, Fb>::get_module_data(const std::string &module)

src/modules/submodules/base_step.hpp

@@ -0,0 +1,68 @@
+//
+// Canadian Hydrological Model - The Canadian Hydrological Model (CHM) is a novel
+// modular unstructured mesh based approach for hydrological modelling
+// Copyright (C) 2018 Christopher Marsh
+//
+// This file is part of Canadian Hydrological Model.
+//
+// Canadian Hydrological Model is free software: you can redistribute it and/or
+// modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Canadian Hydrological Model is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Canadian Hydrological Model.  If not, see
+// <http://www.gnu.org/licenses/>.
+//
+
+#pragma once
+#include <concepts>
+
+/**
+ * @brief Base class for submodules using the Curiously Recurring Template Pattern (CRTP).
+ *
+ * This class enforces that derived classes implement an `execute_impl(Data&) const` method,
+ * and provides a public `execute(Data&) const` method that forwards to the derived implementation.
+ *
+ * The CRTP pattern allows compile-time polymorphism, enabling static dispatch and
+ * avoiding the overhead of virtual functions. This is useful for performance-critical
+ * code or when templates are preferred over inheritance.
+ *
+ * Usage example:
+ * @code
+ * struct MyStep : public base_step<MyStep, MyData> {
+ *     void execute_impl(MyData& d) {
+ *         // Step-specific logic here
+ *     }
+ * };
+ * MyStep step;
+ * MyData data;
+ * step.execute(data); // Calls MyStep::execute_impl(data)
+ * @endcode
+ */
+
+template<typename T, typename Data>
+concept GuaranteeImplementExecute = requires(const T& t, Data& d) {
+    { t.execute_impl(d) } -> std::same_as<void>;
+};
+
+template<class Derived, class Data>
+class base_step {
+protected:
+    base_step() {};
+public:
+    void execute(Data& d) const {
+
+        static_assert(GuaranteeImplementExecute<Derived,Data>,
+                "Derived class must implement: void execute_impl(Data&) const");
+
+        static_cast<const Derived*>(this)->execute_impl(d);
+    }
+    ~base_step() {};
+};

src/modules/submodules/data_base.hpp

@@ -0,0 +1,224 @@
+//
+// Canadian Hydrological Model - The Canadian Hydrological Model (CHM) is a novel
+// modular unstructured mesh based approach for hydrological modelling
+// Copyright (C) 2018 Christopher Marsh
+//
+// This file is part of Canadian Hydrological Model.
+//
+// Canadian Hydrological Model is free software: you can redistribute it and/or
+// modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Canadian Hydrological Model is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Canadian Hydrological Model.  If not, see
+// <http://www.gnu.org/licenses/>.
+//
+
+//
+// Created by Donovan Allum 2025
+//
+
+#pragma once
+
+#include "global.hpp"
+#include "triangulation.hpp"
+#include <limits>
+#include <optional>
+#include <boost/shared_ptr.hpp>
+#include <boost/property_tree/ptree.hpp>
+#include <cstddef>
+#include <stdexcept>
+#include <cassert>
+#include <cstdint>
+#include <concepts>
+#include <type_traits>
+
+/**
+ * @brief Base class for data management with lazy caching and output handling.
+ *
+ * This class provides a framework for managing data with optional caching,
+ * lazy evaluation, and output assignment. It uses CRTP-like patterns with
+ * concepts to enforce interface contracts at compile-time.
+ *
+ * Key features:
+ * - Automatic cache initialization and staleness checking
+ * - Lazy evaluation of values with cache-aware updates
+ * - Type-safe output assignment with runtime checks
+ * - Compile-time concept enforcement for derived cache types and value/output providers
+ *
+ * The class is designed for computational scenarios where:
+ * - Data may be expensive to compute and should be cached
+ * - Cache validity depends on external timestep counters
+ * - Values need to be fetched lazily when accessed
+ * - Outputs must be accumulated safely
+ *
+ * Usage example:
+ * @code
+ * struct MyCache : public cache_base {
+ *     double temperature = default_value<double>();
+ *     int iteration_count = default_value<int>();
+ * };
+ *
+ * class MyData : public data_base<MyCache> {
+ * public:
+ *     MyData(const mesh_elem& face_in, const boost::shared_ptr<global> param, 
+ *            const pt::ptree& cfg) : data_base(face_in, param, cfg) {}
+ *     
+ *     void compute_temperature() {
+ *         update_value(
+ *             [this]() -> auto& { return cache_->temperature; },
+ *             [this]() { return expensive_temperature_calculation(); }
+ *         );
+ *     }
+ *     
+ *     void add_to_output(double contribution) {
+ *         set_output(
+ *             [this]() -> auto& { return output_variable; },
+ *             contribution
+ *         );
+ *     }
+ * };
+ * @endcode
+ *
+ * @tparam CacheType A type derived from cache_base that provides storage
+ *         for cached values. Must satisfy the CacheRules concept.
+ */
+
+struct cache_base 
+{
+    int64_t last_timestep = -1;
+
+    template<typename T>
+    static constexpr T default_value() {
+        if constexpr (std::is_floating_point_v<T>)
+            return std::numeric_limits<T>::quiet_NaN();
+        else if constexpr (std::is_integral_v<T>)
+            return std::numeric_limits<T>::min();
+        else 
+            return T{};
+    };
+
+};
+
+namespace data_base_concepts {
+    template<typename C>
+    concept CacheRules = std::derived_from<C,cache_base>;
+
+    template<typename V>
+    concept ValueRules = 
+        requires(V v) {
+        {v()} -> std::same_as<std::add_lvalue_reference_t<decltype(v())>>;
+    };
+
+    template<typename O,typename T>
+    concept OutputRules = ValueRules<O> &&
+    requires(O o,const T t)
+    {
+        {o()} -> std::convertible_to<T>;
+        {o() += t};
+    };
+};
+
+namespace pt = boost::property_tree;
+
+template<data_base_concepts::CacheRules CacheType>
+class data_base {
+
+    template<typename T>
+    bool constexpr is_unset(T t)
+    {
+        if constexpr (!std::is_floating_point_v<T>)
+            return t == cache_base::default_value<T>();
+        else 
+            return std::isnan(t);
+    };
+
+    bool is_stale();
+
+    void init_cache();
+
+protected:
+
+    data_base(const mesh_elem& face_in, const boost::shared_ptr<global> param, 
+            const pt::ptree& cfg);
+    // Test constructor to skip checks of valid mesh_elem
+    data_base(const mesh_elem& face_in, const boost::shared_ptr<global> param, 
+            const pt::ptree& cfg, bool istest);
+    ~data_base() {};
+
+    const mesh_elem face{nullptr};
+    const boost::shared_ptr<global> global_param;
+    const pt::ptree& cfg_;
+    mutable std::optional<CacheType> cache_;
+
+    template<data_base_concepts::ValueRules Value,typename Fetch>
+    void update_value(Value&& value, const Fetch& fetch);
+
+    template<typename T,data_base_concepts::OutputRules<T> Output>
+    void set_output(Output&& output,const T t);
+
+public:
+    void reset_cache() { cache_.reset(); };
+    const std::optional<CacheType>& get_cache() const { return cache_; }; 
+};
+
+template<data_base_concepts::CacheRules CacheType>
+void data_base<CacheType>::init_cache() {
+    if (!cache_ || is_stale()) {
+        cache_.emplace();
+        cache_->last_timestep = global_param->timestep_counter;
+    }
+}
+
+template<data_base_concepts::CacheRules CacheType>
+bool data_base<CacheType>::is_stale()
+{
+    return cache_->last_timestep != global_param->timestep_counter;
+}
+
+template<data_base_concepts::CacheRules CacheType>
+data_base<CacheType>::data_base(const mesh_elem& face_in, const boost::shared_ptr<global> param, 
+        const pt::ptree& cfg) : face(face_in), global_param(param), cfg_(cfg)
+{
+    if (!face->is_valid())
+        throw std::invalid_argument("Face handle points to an invalid face");
+
+    if (!global_param)
+        throw std::invalid_argument("global parameter holder is null");
+};
+
+template<data_base_concepts::CacheRules CacheType>
+data_base<CacheType>::data_base(const mesh_elem& face_in, const boost::shared_ptr<global> param, 
+        const pt::ptree& cfg, const bool istest) : face(face_in), global_param(param), cfg_(cfg)
+{
+    if (!istest)
+        std::invalid_argument("data_base test constructor called with False istest flag. Should be true.");
+};
+template<data_base_concepts::CacheRules CacheType>
+template<data_base_concepts::ValueRules Value,typename Fetch>
+void data_base<CacheType>::update_value(Value&& value, const Fetch& fetch) {
+    init_cache();
+
+    auto& V = value(); 
+    if ( is_unset(V) )
+    {
+        V = fetch();
+    }
+
+};
+
+template<data_base_concepts::CacheRules CacheType>
+template<typename T,data_base_concepts::OutputRules<T> Output>
+void data_base<CacheType>::set_output(Output&& output,const T t)
+{
+    init_cache();
+
+    output() += t;
+};