xo-allod: + per-type stats + pretty printing

include/xo/alloc/ObjectStatistics.hpp

@@ -0,0 +1,86 @@
+/* file ObjectStatistics.hpp
+ *
+ * author: Roland Conybeare, Aug 2025
+ */
+
+#pragma once
+
+#include "xo/indentlog/print/pretty.hpp"
+#include <vector>
+#include <cstdint>
+
+namespace xo {
+    namespace reflect { class TypeDescrBase; }
+
+    namespace gc {
+        enum class capture_phase {
+            /** snapshot-at-beginning **/
+            sab,
+            /** snapshot-at-end **/
+            sae,
+        };
+
+        /** @class PerObjectTypeStatistics
+         *  @brief statistics for a particular object type
+         *
+         *  Gathered for each leaf type descended from xo::obj::Object.
+         *  See @ref xo::obj::Object::self_tp
+         *
+         *  See @ref GC::capture_object_statistics
+         *  (gathers @ref scanned_n_, @ref scanned_z_)
+         **/
+        struct PerObjectTypeStatistics {
+            using TypeDescr = xo::reflect::TypeDescrBase const *;
+
+            void display(std::ostream & os) const;
+
+            /** stats here are for objects of this type **/
+            TypeDescr td_ = nullptr;
+            /** number of objects scanned **/
+            std::size_t scanned_n_ = 0;
+            /** number of bytes scanned **/
+            std::size_t scanned_z_ = 0;
+            /** number of objects surviving **/
+            std::size_t survive_n_ = 0;
+            /** number of bytes from surviving objects **/
+            std::size_t survive_z_ = 0;
+        };
+
+        inline std::ostream & operator<< (std::ostream & os, const PerObjectTypeStatistics & x) {
+            x.display(os);
+            return os;
+        }
+
+        /** @class ObjectStatistics
+         *  @brief placeholder for type-driven allocation statistics
+         *
+         *  Passed to @ref Object::deep_move for example
+         **/
+        struct ObjectStatistics {
+            void display(std::ostream & os) const;
+
+            /** per-object-type statistics, indexed by TypeId **/
+            std::vector<PerObjectTypeStatistics> per_type_stats_v_;
+        };
+
+        inline std::ostream & operator<< (std::ostream & os, const ObjectStatistics & x) {
+            x.display(os);
+            return os;
+        }
+
+    } /*namespace gc*/
+
+    namespace print {
+        template <>
+        struct ppdetail<xo::gc::PerObjectTypeStatistics> {
+            static bool print_pretty(const ppindentinfo &, const xo::gc::PerObjectTypeStatistics &);
+        };
+
+        template <>
+        struct ppdetail<xo::gc::ObjectStatistics> {
+            static bool print_pretty(const ppindentinfo &, const xo::gc::ObjectStatistics &);
+        };
+    } /*namespace print*/
+} /*namespace xo*/
+
+/* end ObjectStatistics.hpp */