Support retrieving ECS table statistics

libs/ecs/include/psemek/ecs/container.hpp

@@ -11,6 +11,7 @@
 #include <psemek/ecs/detail/index_container.hpp>
 #include <psemek/ecs/accessor.hpp>
 #include <psemek/ecs/exceptions.hpp>
+#include <psemek/ecs/statistics.hpp>
 #include <psemek/util/range.hpp>
 #include <psemek/util/object_pool.hpp>
 
@@ -396,6 +397,8 @@ namespace psemek::ecs
 
 		std::size_t table_count();
 
+		struct statistics statistics();
+
 	private:
 		detail::entity_list entity_list_;
 		detail::table_container table_container_;

libs/ecs/include/psemek/ecs/detail/column.hpp

@@ -54,6 +54,7 @@ namespace psemek::ecs::detail
 
 		virtual std::size_t memory_usage() const = 0;
 
+		virtual std::string describe() const = 0;
 		virtual std::string describe(std::uint32_t row) const = 0;
 
 		virtual ~column() = default;
@@ -90,6 +91,7 @@ namespace psemek::ecs::detail
 
 		std::size_t memory_usage() const override;
 
+		std::string describe() const override;
 		std::string describe(std::uint32_t row) const override;
 
 		~column_impl() override;
@@ -118,6 +120,7 @@ namespace psemek::ecs::detail
 
 		std::size_t memory_usage() const override;
 
+		std::string describe() const override;
 		std::string describe(std::uint32_t row) const override;
 
 		~column_impl() override;
@@ -215,6 +218,12 @@ namespace psemek::ecs::detail
 		return sizeof(Component) * row_count_;
 	}
 
+	template <typename Component, bool Empty>
+	std::string column_impl<Component, Empty>::describe() const
+	{
+		return detail::describe<Component>();
+	}
+
 	template <typename Component, bool Empty>
 	std::string column_impl<Component, Empty>::describe(std::uint32_t row) const
 	{
@@ -299,6 +308,12 @@ namespace psemek::ecs::detail
 		return sizeof(Component);
 	}
 
+	template <typename Component>
+	std::string column_impl<Component, true>::describe() const
+	{
+		return detail::describe<Component>();
+	}
+
 	template <typename Component>
 	std::string column_impl<Component, true>::describe(std::uint32_t) const
 	{

libs/ecs/include/psemek/ecs/detail/describe.hpp

@@ -8,11 +8,11 @@ namespace psemek::ecs::detail
 {
 
 	template <typename Component>
-	std::string describe(Component const & component)
+	std::string describe()
 	{
-		if constexpr (requires {component.to_string();})
+		if constexpr (requires {Component::to_string();})
 		{
-			return component.to_string();
+			return Component::to_string();
 		}
 		else
 		{
@@ -23,4 +23,17 @@ namespace psemek::ecs::detail
 		}
 	}
 
+	template <typename Component>
+	std::string describe(Component const & component)
+	{
+		if constexpr (requires {component.to_string();})
+		{
+			return component.to_string();
+		}
+		else
+		{
+			return describe<Component>();
+		}
+	}
+
 }

libs/ecs/include/psemek/ecs/detail/table.hpp

@@ -81,6 +81,7 @@ namespace psemek::ecs::detail
 
 		std::size_t memory_usage() const;
 
+		std::string describe() const;
 		std::string describe(std::uint32_t row) const;
 
 	protected:

libs/ecs/include/psemek/ecs/statistics.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace psemek::ecs
+{
+
+	struct table_statistics
+	{
+		std::string description;
+		std::size_t entity_count;
+	};
+
+	struct statistics
+	{
+		std::vector<table_statistics> tables;
+	};
+
+}

libs/ecs/source/container.cpp

@@ -138,4 +138,16 @@ namespace psemek::ecs
 		return table_container_.table_count();
 	}
 
+	statistics container::statistics()
+	{
+		struct statistics result;
+
+		table_container_.apply([&](detail::table & table)
+		{
+			result.tables.push_back({table.describe(), table.row_count()});
+		}, {}, {});
+
+		return result;
+	}
+
 }

libs/ecs/source/detail/table.cpp

@@ -188,6 +188,18 @@ namespace psemek::ecs::detail
 		return result;
 	}
 
+	std::string table::describe() const
+	{
+		std::string result;
+		for (std::size_t i = 0; i < columns_.size(); ++i)
+		{
+			if (i > 0)
+				result += ";";
+			result += columns_[i]->describe();
+		}
+		return result;
+	}
+
 	std::string table::describe(std::uint32_t row) const
 	{
 		std::string result;