add LuaMemTracker & limit Lua memory size

LuaMemTracker.cpp

+#include "LuaMemTracker.h"
+#include <lauxlib.h>
+
+LuaMemTracker::LuaMemTracker(size_t mem_limit)
+		: limit(mem_limit) {
+	lua_State* tmp_L = luaL_newstate();  // get default alloc
+	real_alloc = lua_getallocf(tmp_L, &real_ud);
+	lua_close(tmp_L);
+
+#ifdef YGOPRO_LOG_LUA_MEMORY_SIZE
+	time_t now = time(nullptr);
+	char filename[64];
+	std::snprintf(filename, sizeof(filename), "memtrace-%ld.log", static_cast<long>(now));
+
+	log_file = std::fopen(filename, "a");
+	if (log_file) {
+		std::fprintf(log_file, "---- Lua memory tracking started ----\n");
+	}
+#endif
+}
+
+LuaMemTracker::~LuaMemTracker() {
+#ifdef YGOPRO_LOG_LUA_MEMORY_SIZE
+	if (log_file) {
+		std::fprintf(log_file, "---- Lua memory tracking ended ----\n");
+		std::fclose(log_file);
+		log_file = nullptr;
+	}
+#endif
+}
+
+void* LuaMemTracker::AllocThunk(void* ud, void* ptr, size_t osize, size_t nsize) {
+	return static_cast<LuaMemTracker*>(ud)->Alloc(ptr, osize, nsize);
+}
+
+void* LuaMemTracker::Alloc(void* ptr, size_t osize, size_t nsize) {
+	if (nsize == 0) {
+		if (ptr && osize <= total_allocated) {
+			total_allocated -= osize;
+		}
+		return real_alloc(real_ud, ptr, osize, nsize);
+	} else {
+		size_t projected = total_allocated - osize + nsize;
+		if (limit && projected > limit) {
+			return nullptr;  // over limit
+		}
+		void* newptr = real_alloc(real_ud, ptr, osize, nsize);
+		if (newptr) {
+			total_allocated = projected;
+#ifdef YGOPRO_LOG_LUA_MEMORY_SIZE
+			write_log();
+#endif
+		}
+		return newptr;
+	}
+}
+
+#ifdef YGOPRO_LOG_LUA_MEMORY_SIZE
+void LuaMemTracker::write_log() {
+	if (!log_file) return;
+
+	time_t now = time(nullptr);
+	struct tm* tm_info = localtime(&now);
+
+	char time_buf[32];
+	std::strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S", tm_info);
+
+	if (total_allocated > max_used)
+		max_used = total_allocated;
+
+	if (limit)
+		std::fprintf(log_file, "%s | used = %zu bytes | max_used = %zu bytes | limit = %zu\n",
+			time_buf, total_allocated, max_used, limit);
+	else
+		std::fprintf(log_file, "%s | used = %zu bytes | max_used = %zu bytes | limit = unlimited\n",
+			time_buf, total_allocated, max_used);
+
+	std::fflush(log_file);  // make it write instantly
+}
+#endif

LuaMemTracker.h

+#ifndef LUA_MEM_TRACKER_H
+#define LUA_MEM_TRACKER_H
+
+#include <cstdlib>
+#include <cstddef>
+#include <lua.h>
+
+#ifdef YGOPRO_LOG_LUA_MEMORY_SIZE
+#include <ctime>     // time_t
+#include <cstdio>    // FILE*, fopen, fprintf
+#endif
+
+class LuaMemTracker {
+public:
+	LuaMemTracker(size_t mem_limit = 0);
+	~LuaMemTracker();
+	static void* AllocThunk(void* ud, void* ptr, size_t osize, size_t nsize);
+	void* Alloc(void* ptr, size_t osize, size_t nsize);
+
+	size_t get_total() const { return total_allocated; }
+	size_t get_limit() const { return limit; }
+
+private:
+#ifdef YGOPRO_LOG_LUA_MEMORY_SIZE
+	FILE* log_file = nullptr;
+	void write_log();
+#endif
+
+	lua_Alloc real_alloc;
+	void* real_ud;
+	size_t total_allocated = 0;
+	size_t limit = 0;
+#ifdef YGOPRO_LOG_LUA_MEMORY_SIZE
+	size_t max_used = 0; // for logging purposes, to track peak memory usage
+#endif
+};
+
+#endif // LUA_MEM_TRACKER_H

interpreter.cpp

@@ -15,7 +15,8 @@
 #include "interpreter.h"
 
 interpreter::interpreter(duel* pd): coroutines(256) {
-	lua_state = luaL_newstate();
+	mem_tracker = new LuaMemTracker(YGOPRO_LUA_MEMORY_SIZE);
+	lua_state = lua_newstate(LuaMemTracker::AllocThunk, mem_tracker);
 	current_state = lua_state;
 	pduel = pd;
 	std::memcpy(lua_getextraspace(lua_state), &pd, LUA_EXTRASPACE); //set_duel_info
@@ -54,6 +55,7 @@ interpreter::interpreter(duel* pd): coroutines(256) {
 }
 interpreter::~interpreter() {
 	lua_close(lua_state);
+	delete mem_tracker;
 }
 void interpreter::register_card(card *pcard) {
 	if (!pcard)

interpreter.h

@@ -16,6 +16,7 @@
 #include <list>
 #include <vector>
 #include <cstdio>
+#include "LuaMemTracker.h"
 
 class card;
 struct card_data;
@@ -47,6 +48,7 @@ public:
 	char msgbuf[64];
 	lua_State* lua_state;
 	lua_State* current_state;
+	LuaMemTracker* mem_tracker;
 	param_list params;
 	param_list resumes;
 	coroutine_map coroutines;
@@ -97,4 +99,8 @@ public:
 #define COROUTINE_YIELD		2
 #define COROUTINE_ERROR		3
 
+#ifndef YGOPRO_LUA_MEMORY_SIZE
+#define YGOPRO_LUA_MEMORY_SIZE 67108864 // 64 MB
+#endif
+
 #endif /* INTERPRETER_H_ */