From 68d4adcad2e93b32ab7fb8f6a8874706c71ccd3f Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Mon, 3 Jun 2024 11:35:37 +0300
Subject: [PATCH] Support reporting ECS memory usage

---
 libs/ecs/include/psemek/ecs/container.hpp     | 15 +++++++++++++++
 libs/ecs/include/psemek/ecs/detail/column.hpp | 18 ++++++++++++++++++
 libs/ecs/include/psemek/ecs/detail/table.hpp  |  2 ++
 libs/ecs/source/detail/table.cpp              |  8 ++++++++
 4 files changed, 43 insertions(+)

diff --git a/libs/ecs/include/psemek/ecs/container.hpp b/libs/ecs/include/psemek/ecs/container.hpp
index 1040bf97..04b7232f 100644
--- a/libs/ecs/include/psemek/ecs/container.hpp
+++ b/libs/ecs/include/psemek/ecs/container.hpp
@@ -378,6 +378,9 @@ namespace psemek::ecs
 		template <typename Index, typename ... Args>
 		Index & index(Args && ... args);
 
+		template <typename ... Components>
+		std::size_t memory_usage();
+
 	private:
 		detail::entity_list entity_list_;
 		detail::table_container table_container_;
@@ -716,4 +719,16 @@ namespace psemek::ecs
 		return result;
 	}
 
+	template <typename ... Components>
+	std::size_t container::memory_usage()
+	{
+		auto cache = this->cache<Components...>();
+		std::size_t result = 0;
+
+		for (auto const & entry : cache->entries)
+			result += entry.table->memory_usage();
+
+		return result;
+	}
+
 }
diff --git a/libs/ecs/include/psemek/ecs/detail/column.hpp b/libs/ecs/include/psemek/ecs/detail/column.hpp
index 2639f9e7..1e1cd358 100644
--- a/libs/ecs/include/psemek/ecs/detail/column.hpp
+++ b/libs/ecs/include/psemek/ecs/detail/column.hpp
@@ -51,6 +51,8 @@ namespace psemek::ecs::detail
 
 		virtual std::unique_ptr<column> clone() const = 0;
 
+		virtual std::size_t memory_usage() const = 0;
+
 		virtual ~column() = default;
 
 	protected:
@@ -83,6 +85,8 @@ namespace psemek::ecs::detail
 
 		std::unique_ptr<column> clone() const override;
 
+		std::size_t memory_usage() const override;
+
 		~column_impl() override;
 
 	private:
@@ -107,6 +111,8 @@ namespace psemek::ecs::detail
 
 		std::unique_ptr<column> clone() const override;
 
+		std::size_t memory_usage() const override;
+
 		~column_impl() override;
 	};
 
@@ -196,6 +202,12 @@ namespace psemek::ecs::detail
 		return std::make_unique<column_impl<Component, Empty>>();
 	}
 
+	template <typename Component, bool Empty>
+	std::size_t column_impl<Component, Empty>::memory_usage() const
+	{
+		return sizeof(Component) * row_count_;
+	}
+
 	template <typename Component, bool Empty>
 	column_impl<Component, Empty>::~column_impl()
 	{
@@ -268,6 +280,12 @@ namespace psemek::ecs::detail
 		return std::make_unique<column_impl<Component, true>>();
 	}
 
+	template <typename Component>
+	std::size_t column_impl<Component, true>::memory_usage() const
+	{
+		return sizeof(Component);
+	}
+
 	template <typename Component>
 	column_impl<Component, true>::~column_impl()
 	{
diff --git a/libs/ecs/include/psemek/ecs/detail/table.hpp b/libs/ecs/include/psemek/ecs/detail/table.hpp
index 4f853713..a2ba752e 100644
--- a/libs/ecs/include/psemek/ecs/detail/table.hpp
+++ b/libs/ecs/include/psemek/ecs/detail/table.hpp
@@ -79,6 +79,8 @@ namespace psemek::ecs::detail
 		void trigger_destructors(container & container, std::uint32_t row);
 		void trigger_destructors(container & container, std::uint32_t row, util::hash_set<util::uuid> const & detached_components);
 
+		std::size_t memory_usage() const;
+
 	protected:
 		std::size_t hash_;
 		std::vector<std::unique_ptr<detail::column>> columns_;
diff --git a/libs/ecs/source/detail/table.cpp b/libs/ecs/source/detail/table.cpp
index e57e7c6e..0e1bafcd 100644
--- a/libs/ecs/source/detail/table.cpp
+++ b/libs/ecs/source/detail/table.cpp
@@ -178,4 +178,12 @@ namespace psemek::ecs::detail
 			callback(container, *this, row, detached_components, false);
 	}
 
+	std::size_t table::memory_usage() const
+	{
+		std::size_t result = 0;
+		for (auto const & column : columns_)
+			result += column->memory_usage();
+		return result;
+	}
+
 }