Refactor ABM/LBM related code

src/script/cpp_api/s_env.cpp

@@ -25,8 +25,102 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapgen/mapgen.h"
 #include "lua_api/l_env.h"
 #include "server.h"
+#include "scripting_server.h"
 #include "script/common/c_content.h"
 
+/*
+	LuaABM & LuaLBM
+*/
+
+class LuaABM : public ActiveBlockModifier {
+private:
+	int m_id;
+
+	std::vector<std::string> m_trigger_contents;
+	std::vector<std::string> m_required_neighbors;
+	float m_trigger_interval;
+	u32 m_trigger_chance;
+	bool m_simple_catch_up;
+	s16 m_min_y;
+	s16 m_max_y;
+public:
+	LuaABM(int id,
+			const std::vector<std::string> &trigger_contents,
+			const std::vector<std::string> &required_neighbors,
+			float trigger_interval, u32 trigger_chance, bool simple_catch_up,
+			s16 min_y, s16 max_y):
+		m_id(id),
+		m_trigger_contents(trigger_contents),
+		m_required_neighbors(required_neighbors),
+		m_trigger_interval(trigger_interval),
+		m_trigger_chance(trigger_chance),
+		m_simple_catch_up(simple_catch_up),
+		m_min_y(min_y),
+		m_max_y(max_y)
+	{
+	}
+	virtual const std::vector<std::string> &getTriggerContents() const
+	{
+		return m_trigger_contents;
+	}
+	virtual const std::vector<std::string> &getRequiredNeighbors() const
+	{
+		return m_required_neighbors;
+	}
+	virtual float getTriggerInterval()
+	{
+		return m_trigger_interval;
+	}
+	virtual u32 getTriggerChance()
+	{
+		return m_trigger_chance;
+	}
+	virtual bool getSimpleCatchUp()
+	{
+		return m_simple_catch_up;
+	}
+	virtual s16 getMinY()
+	{
+		return m_min_y;
+	}
+	virtual s16 getMaxY()
+	{
+		return m_max_y;
+	}
+
+	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n,
+			u32 active_object_count, u32 active_object_count_wider)
+	{
+		auto *script = env->getScriptIface();
+		script->triggerABM(m_id, p, n, active_object_count, active_object_count_wider);
+	}
+};
+
+class LuaLBM : public LoadingBlockModifierDef
+{
+private:
+	int m_id;
+public:
+	LuaLBM(int id,
+			const std::vector<std::string> &trigger_contents,
+			const std::string &name, bool run_at_every_load):
+		m_id(id)
+	{
+		this->run_at_every_load = run_at_every_load;
+		this->trigger_contents = trigger_contents;
+		this->name = name;
+	}
+
+	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n, float dtime_s)
+	{
+		auto *script = env->getScriptIface();
+		script->triggerLBM(m_id, p, n, dtime_s);
+	}
+};
+
+/*
+	ScriptApiEnv
+*/
 
 void ScriptApiEnv::environment_OnGenerated(v3s16 minp, v3s16 maxp,
 	u32 blockseed)
@@ -46,7 +140,6 @@ void ScriptApiEnv::environment_OnGenerated(v3s16 minp, v3s16 maxp,
 void ScriptApiEnv::environment_Step(float dtime)
 {
 	SCRIPTAPI_PRECHECKHEADER
-	//infostream << "scriptapi_environment_step" << std::endl;
 
 	// Get core.registered_globalsteps
 	lua_getglobal(L, "core");
@@ -76,12 +169,40 @@ void ScriptApiEnv::player_event(ServerActiveObject *player, const std::string &t
 void ScriptApiEnv::initializeEnvironment(ServerEnvironment *env)
 {
 	SCRIPTAPI_PRECHECKHEADER
+
+	assert(env);
 	verbosestream << "ScriptApiEnv: Environment initialized" << std::endl;
 	setEnv(env);
 
-	/*
-		Add {Loading,Active}BlockModifiers to environment
-	*/
+	readABMs();
+	readLBMs();
+}
+
+// Reads a single or a list of node names into a vector
+bool ScriptApiEnv::read_nodenames(lua_State *L, int idx, std::vector<std::string> &to)
+{
+	if (lua_istable(L, idx)) {
+		const int table = idx < 0 ? (lua_gettop(L) + idx + 1) : idx;
+		lua_pushnil(L);
+		while (lua_next(L, table)) {
+			// key at index -2 and value at index -1
+			luaL_checktype(L, -1, LUA_TSTRING);
+			to.emplace_back(readParam<std::string>(L, -1));
+			// removes value, keeps key for next iteration
+			lua_pop(L, 1);
+		}
+	} else if (lua_isstring(L, idx)) {
+		to.emplace_back(readParam<std::string>(L, idx));
+	} else {
+		return false;
+	}
+	return true;
+}
+
+void ScriptApiEnv::readABMs()
+{
+	SCRIPTAPI_PRECHECKHEADER
+	auto *env = reinterpret_cast<ServerEnvironment*>(getEnv());
 
 	// Get core.registered_abms
 	lua_getglobal(L, "core");
@@ -100,36 +221,12 @@ void ScriptApiEnv::initializeEnvironment(ServerEnvironment *env)
 
 		std::vector<std::string> trigger_contents;
 		lua_getfield(L, current_abm, "nodenames");
-		if (lua_istable(L, -1)) {
-			int table = lua_gettop(L);
-			lua_pushnil(L);
-			while (lua_next(L, table)) {
-				// key at index -2 and value at index -1
-				luaL_checktype(L, -1, LUA_TSTRING);
-				trigger_contents.emplace_back(readParam<std::string>(L, -1));
-				// removes value, keeps key for next iteration
-				lua_pop(L, 1);
-			}
-		} else if (lua_isstring(L, -1)) {
-			trigger_contents.emplace_back(readParam<std::string>(L, -1));
-		}
+		read_nodenames(L, -1, trigger_contents);
 		lua_pop(L, 1);
 
 		std::vector<std::string> required_neighbors;
 		lua_getfield(L, current_abm, "neighbors");
-		if (lua_istable(L, -1)) {
-			int table = lua_gettop(L);
-			lua_pushnil(L);
-			while (lua_next(L, table)) {
-				// key at index -2 and value at index -1
-				luaL_checktype(L, -1, LUA_TSTRING);
-				required_neighbors.emplace_back(readParam<std::string>(L, -1));
-				// removes value, keeps key for next iteration
-				lua_pop(L, 1);
-			}
-		} else if (lua_isstring(L, -1)) {
-			required_neighbors.emplace_back(readParam<std::string>(L, -1));
-		}
+		read_nodenames(L, -1, required_neighbors);
 		lua_pop(L, 1);
 
 		float trigger_interval = 10.0;
@@ -151,7 +248,7 @@ void ScriptApiEnv::initializeEnvironment(ServerEnvironment *env)
 		luaL_checktype(L, current_abm + 1, LUA_TFUNCTION);
 		lua_pop(L, 1);
 
-		LuaABM *abm = new LuaABM(L, id, trigger_contents, required_neighbors,
+		LuaABM *abm = new LuaABM(id, trigger_contents, required_neighbors,
 			trigger_interval, trigger_chance, simple_catch_up, min_y, max_y);
 
 		env->addActiveBlockModifier(abm);
@@ -160,6 +257,12 @@ void ScriptApiEnv::initializeEnvironment(ServerEnvironment *env)
 		lua_pop(L, 1);
 	}
 	lua_pop(L, 1);
+}
+
+void ScriptApiEnv::readLBMs()
+{
+	SCRIPTAPI_PRECHECKHEADER
+	auto *env = reinterpret_cast<ServerEnvironment*>(getEnv());
 
 	// Get core.registered_lbms
 	lua_getglobal(L, "core");
@@ -177,21 +280,9 @@ void ScriptApiEnv::initializeEnvironment(ServerEnvironment *env)
 		int id = lua_tonumber(L, -2);
 		int current_lbm = lua_gettop(L);
 
-		std::set<std::string> trigger_contents;
+		std::vector<std::string> trigger_contents;
 		lua_getfield(L, current_lbm, "nodenames");
-		if (lua_istable(L, -1)) {
-			int table = lua_gettop(L);
-			lua_pushnil(L);
-			while (lua_next(L, table)) {
-				// key at index -2 and value at index -1
-				luaL_checktype(L, -1, LUA_TSTRING);
-				trigger_contents.insert(readParam<std::string>(L, -1));
-				// removes value, keeps key for next iteration
-				lua_pop(L, 1);
-			}
-		} else if (lua_isstring(L, -1)) {
-			trigger_contents.insert(readParam<std::string>(L, -1));
-		}
+		read_nodenames(L, -1, trigger_contents);
 		lua_pop(L, 1);
 
 		std::string name;
@@ -204,7 +295,7 @@ void ScriptApiEnv::initializeEnvironment(ServerEnvironment *env)
 		luaL_checktype(L, current_lbm + 1, LUA_TFUNCTION);
 		lua_pop(L, 1);
 
-		LuaLBM *lbm = new LuaLBM(L, id, trigger_contents, name,
+		LuaLBM *lbm = new LuaLBM(id, trigger_contents, name,
 			run_at_every_load);
 
 		env->addLoadingBlockModifierDef(lbm);
@@ -288,7 +379,7 @@ void ScriptApiEnv::on_liquid_transformed(
 	int index = 1;
 	lua_createtable(L, list.size(), 0);
 	lua_createtable(L, list.size(), 0);
-	for(std::pair<v3s16, MapNode> p : list) {
+	for(auto &p : list) {
 		lua_pushnumber(L, index);
 		push_v3s16(L, p.first);
 		lua_rawset(L, -4);
@@ -332,3 +423,78 @@ bool ScriptApiEnv::has_on_mapblocks_changed()
 	luaL_checktype(L, -1, LUA_TTABLE);
 	return lua_objlen(L, -1) > 0;
 }
+
+void ScriptApiEnv::triggerABM(int id, v3s16 p, MapNode n,
+		u32 active_object_count, u32 active_object_count_wider)
+{
+	SCRIPTAPI_PRECHECKHEADER
+
+	int error_handler = PUSH_ERROR_HANDLER(L);
+
+	// Get registered_abms
+	lua_getglobal(L, "core");
+	lua_getfield(L, -1, "registered_abms");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	lua_remove(L, -2); // Remove core
+
+	// Get registered_abms[m_id]
+	lua_pushinteger(L, id);
+	lua_gettable(L, -2);
+	FATAL_ERROR_IF(lua_isnil(L, -1), "Entry with given id not found in registered_abms table");
+	lua_remove(L, -2); // Remove registered_abms
+
+	setOriginFromTable(-1);
+
+	// Call action
+	luaL_checktype(L, -1, LUA_TTABLE);
+	lua_getfield(L, -1, "action");
+	luaL_checktype(L, -1, LUA_TFUNCTION);
+	lua_remove(L, -2); // Remove registered_abms[m_id]
+	push_v3s16(L, p);
+	pushnode(L, n);
+	lua_pushnumber(L, active_object_count);
+	lua_pushnumber(L, active_object_count_wider);
+
+	int result = lua_pcall(L, 4, 0, error_handler);
+	if (result)
+		scriptError(result, "LuaABM::trigger");
+
+	lua_pop(L, 1); // Pop error handler
+}
+
+void ScriptApiEnv::triggerLBM(int id, v3s16 p,
+	const MapNode n, const float dtime_s)
+{
+	SCRIPTAPI_PRECHECKHEADER
+
+	int error_handler = PUSH_ERROR_HANDLER(L);
+
+	// Get registered_lbms
+	lua_getglobal(L, "core");
+	lua_getfield(L, -1, "registered_lbms");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	lua_remove(L, -2); // Remove core
+
+	// Get registered_lbms[m_id]
+	lua_pushinteger(L, id);
+	lua_gettable(L, -2);
+	FATAL_ERROR_IF(lua_isnil(L, -1), "Entry with given id not found in registered_lbms table");
+	lua_remove(L, -2); // Remove registered_lbms
+
+	setOriginFromTable(-1);
+
+	// Call action
+	luaL_checktype(L, -1, LUA_TTABLE);
+	lua_getfield(L, -1, "action");
+	luaL_checktype(L, -1, LUA_TFUNCTION);
+	lua_remove(L, -2); // Remove registered_lbms[m_id]
+	push_v3s16(L, p);
+	pushnode(L, n);
+	lua_pushnumber(L, dtime_s);
+
+	int result = lua_pcall(L, 3, 0, error_handler);
+	if (result)
+		scriptError(result, "LuaLBM::trigger");
+
+	lua_pop(L, 1); // Pop error handler
+}

src/script/cpp_api/s_env.h

@@ -55,5 +55,19 @@ public:
 	// Determines whether there are any on_mapblocks_changed callbacks
 	bool has_on_mapblocks_changed();
 
+	// Initializes environment and loads some definitions from Lua
 	void initializeEnvironment(ServerEnvironment *env);
+
+	void triggerABM(int id, v3s16 p, MapNode n,
+			u32 active_object_count, u32 active_object_count_wider);
+
+	void triggerLBM(int id, v3s16 p, MapNode n, float dtime_s);
+
+private:
+	void readABMs();
+
+	void readLBMs();
+
+	// Reads a single or a list of node names into a vector
+	static bool read_nodenames(lua_State *L, int idx, std::vector<std::string> &to);
 };

src/script/lua_api/l_env.cpp

@@ -65,93 +65,6 @@ const EnumString ModApiEnvBase::es_BlockStatusType[] =
 
 ///////////////////////////////////////////////////////////////////////////////
 
-
-void LuaABM::trigger(ServerEnvironment *env, v3s16 p, MapNode n,
-		u32 active_object_count, u32 active_object_count_wider)
-{
-	ServerScripting *scriptIface = env->getScriptIface();
-	scriptIface->realityCheck();
-
-	lua_State *L = scriptIface->getStack();
-	sanity_check(lua_checkstack(L, 20));
-	StackUnroller stack_unroller(L);
-
-	int error_handler = PUSH_ERROR_HANDLER(L);
-
-	// Get registered_abms
-	lua_getglobal(L, "core");
-	lua_getfield(L, -1, "registered_abms");
-	luaL_checktype(L, -1, LUA_TTABLE);
-	lua_remove(L, -2); // Remove core
-
-	// Get registered_abms[m_id]
-	lua_pushinteger(L, m_id);
-	lua_gettable(L, -2);
-	if(lua_isnil(L, -1))
-		FATAL_ERROR("");
-	lua_remove(L, -2); // Remove registered_abms
-
-	scriptIface->setOriginFromTable(-1);
-
-	// Call action
-	luaL_checktype(L, -1, LUA_TTABLE);
-	lua_getfield(L, -1, "action");
-	luaL_checktype(L, -1, LUA_TFUNCTION);
-	lua_remove(L, -2); // Remove registered_abms[m_id]
-	push_v3s16(L, p);
-	pushnode(L, n);
-	lua_pushnumber(L, active_object_count);
-	lua_pushnumber(L, active_object_count_wider);
-
-	int result = lua_pcall(L, 4, 0, error_handler);
-	if (result)
-		scriptIface->scriptError(result, "LuaABM::trigger");
-
-	lua_pop(L, 1); // Pop error handler
-}
-
-void LuaLBM::trigger(ServerEnvironment *env, v3s16 p,
-	const MapNode n, const float dtime_s)
-{
-	ServerScripting *scriptIface = env->getScriptIface();
-	scriptIface->realityCheck();
-
-	lua_State *L = scriptIface->getStack();
-	sanity_check(lua_checkstack(L, 20));
-	StackUnroller stack_unroller(L);
-
-	int error_handler = PUSH_ERROR_HANDLER(L);
-
-	// Get registered_lbms
-	lua_getglobal(L, "core");
-	lua_getfield(L, -1, "registered_lbms");
-	luaL_checktype(L, -1, LUA_TTABLE);
-	lua_remove(L, -2); // Remove core
-
-	// Get registered_lbms[m_id]
-	lua_pushinteger(L, m_id);
-	lua_gettable(L, -2);
-	FATAL_ERROR_IF(lua_isnil(L, -1), "Entry with given id not found in registered_lbms table");
-	lua_remove(L, -2); // Remove registered_lbms
-
-	scriptIface->setOriginFromTable(-1);
-
-	// Call action
-	luaL_checktype(L, -1, LUA_TTABLE);
-	lua_getfield(L, -1, "action");
-	luaL_checktype(L, -1, LUA_TFUNCTION);
-	lua_remove(L, -2); // Remove registered_lbms[m_id]
-	push_v3s16(L, p);
-	pushnode(L, n);
-	lua_pushnumber(L, dtime_s);
-
-	int result = lua_pcall(L, 3, 0, error_handler);
-	if (result)
-		scriptIface->scriptError(result, "LuaLBM::trigger");
-
-	lua_pop(L, 1); // Pop error handler
-}
-
 int LuaRaycast::l_next(lua_State *L)
 {
 	GET_PLAIN_ENV_PTR;

src/script/lua_api/l_env.h

@@ -20,9 +20,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #pragma once
 
 #include "lua_api/l_base.h"
-#include "serverenvironment.h"
 #include "raycast.h"
 
+class ServerScripting;
+
 // base class containing helpers
 class ModApiEnvBase : public ModApiBase {
 protected:
@@ -281,82 +282,6 @@ public:
 	static void InitializeEmerge(lua_State *L, int top);
 };
 
-class LuaABM : public ActiveBlockModifier {
-private:
-	int m_id;
-
-	std::vector<std::string> m_trigger_contents;
-	std::vector<std::string> m_required_neighbors;
-	float m_trigger_interval;
-	u32 m_trigger_chance;
-	bool m_simple_catch_up;
-	s16 m_min_y;
-	s16 m_max_y;
-public:
-	LuaABM(lua_State *L, int id,
-			const std::vector<std::string> &trigger_contents,
-			const std::vector<std::string> &required_neighbors,
-			float trigger_interval, u32 trigger_chance, bool simple_catch_up, s16 min_y, s16 max_y):
-		m_id(id),
-		m_trigger_contents(trigger_contents),
-		m_required_neighbors(required_neighbors),
-		m_trigger_interval(trigger_interval),
-		m_trigger_chance(trigger_chance),
-		m_simple_catch_up(simple_catch_up),
-		m_min_y(min_y),
-		m_max_y(max_y)
-	{
-	}
-	virtual const std::vector<std::string> &getTriggerContents() const
-	{
-		return m_trigger_contents;
-	}
-	virtual const std::vector<std::string> &getRequiredNeighbors() const
-	{
-		return m_required_neighbors;
-	}
-	virtual float getTriggerInterval()
-	{
-		return m_trigger_interval;
-	}
-	virtual u32 getTriggerChance()
-	{
-		return m_trigger_chance;
-	}
-	virtual bool getSimpleCatchUp()
-	{
-		return m_simple_catch_up;
-	}
-	virtual s16 getMinY()
-	{
-		return m_min_y;
-	}
-	virtual s16 getMaxY()
-	{
-		return m_max_y;
-	}
-	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n,
-			u32 active_object_count, u32 active_object_count_wider);
-};
-
-class LuaLBM : public LoadingBlockModifierDef
-{
-private:
-	int m_id;
-public:
-	LuaLBM(lua_State *L, int id,
-			const std::set<std::string> &trigger_contents,
-			const std::string &name,
-			bool run_at_every_load):
-		m_id(id)
-	{
-		this->run_at_every_load = run_at_every_load;
-		this->trigger_contents = trigger_contents;
-		this->name = name;
-	}
-	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n, float dtime_s);
-};
-
 //! Lua wrapper for RaycastState objects
 class LuaRaycast : public ModApiBase
 {

src/serverenvironment.cpp

@@ -77,12 +77,12 @@ ABMWithState::ABMWithState(ActiveBlockModifier *abm_):
 	LBMManager
 */
 
-void LBMContentMapping::deleteContents()
+LBMContentMapping::~LBMContentMapping()
 {
-	for (auto &it : lbm_list) {
+	map.clear();
+	for (auto &it : lbm_list)
 		delete it;
 }
-}
 
 void LBMContentMapping::addLBM(LoadingBlockModifierDef *lbm_def, IGameDef *gamedef)
 {
@@ -90,29 +90,32 @@ void LBMContentMapping::addLBM(LoadingBlockModifierDef *lbm_def, IGameDef *gamed
 	// Unknown names get added to the global NameIdMapping.
 	const NodeDefManager *nodedef = gamedef->ndef();
 
+	FATAL_ERROR_IF(CONTAINS(lbm_list, lbm_def), "Same LBM registered twice");
 	lbm_list.push_back(lbm_def);
 
-	for (const std::string &nodeTrigger: lbm_def->trigger_contents) {
 	std::vector<content_t> c_ids;
-		bool found = nodedef->getIds(nodeTrigger, c_ids);
+
+	for (const auto &node : lbm_def->trigger_contents) {
+		bool found = nodedef->getIds(node, c_ids);
 		if (!found) {
-			content_t c_id = gamedef->allocateUnknownNodeId(nodeTrigger);
+			content_t c_id = gamedef->allocateUnknownNodeId(node);
 			if (c_id == CONTENT_IGNORE) {
 				// Seems it can't be allocated.
-				warningstream << "Could not internalize node name \"" << nodeTrigger
+				warningstream << "Could not internalize node name \"" << node
 					<< "\" while loading LBM \"" << lbm_def->name << "\"." << std::endl;
 				continue;
 			}
 			c_ids.push_back(c_id);
 		}
+	}
 
-		for (content_t c_id : c_ids) {
+	SORT_AND_UNIQUE(c_ids);
+
+	for (content_t c_id : c_ids)
 		map[c_id].push_back(lbm_def);
 }
-	}
-}
 
-const std::vector<LoadingBlockModifierDef *> *
+const LBMContentMapping::lbm_vector *
 LBMContentMapping::lookup(content_t c) const
 {
 	lbm_map::const_iterator it = map.find(c);
@@ -130,9 +133,7 @@ LBMManager::~LBMManager()
 		delete m_lbm_def.second;
 	}
 
-	for (auto &it : m_lbm_lookup) {
-		(it.second).deleteContents();
-	}
+	m_lbm_lookup.clear();
 }
 
 void LBMManager::addLBMDef(LoadingBlockModifierDef *lbm_def)
@@ -236,7 +237,7 @@ std::string LBMManager::createIntroductionTimesString()
 	std::ostringstream oss;
 	for (const auto &it : m_lbm_lookup) {
 		u32 time = it.first;
-		const std::vector<LoadingBlockModifierDef *> &lbm_list = it.second.lbm_list;
+		auto &lbm_list = it.second.getList();
 		for (const auto &lbm_def : lbm_list) {
 			// Don't add if the LBM runs at every load,
 			// then introducement time is hardcoded
@@ -255,16 +256,17 @@ void LBMManager::applyLBMs(ServerEnvironment *env, MapBlock *block,
 	// Precondition, we need m_lbm_lookup to be initialized
 	FATAL_ERROR_IF(!m_query_mode,
 		"attempted to query on non fully set up LBMManager");
-	v3s16 pos_of_block = block->getPosRelative();
+
+	const v3s16 pos_of_block = block->getPosRelative();
 	v3s16 pos;
 	MapNode n;
 	content_t c;
 	auto it = getLBMsIntroducedAfter(stamp);
+	// Note: the iteration count of this outer loop is typically very low, so it's ok.
 	for (; it != m_lbm_lookup.end(); ++it) {
-		// Cache previous version to speedup lookup which has a very high performance
-		// penalty on each call
+		// Cache previous lookup result since it has a high performance penalty.
 		content_t previous_c = CONTENT_IGNORE;
-		const std::vector<LoadingBlockModifierDef *> *lbm_list = nullptr;
+		const LBMContentMapping::lbm_vector *lbm_list = nullptr;
 
 		for (pos.Z = 0; pos.Z < MAP_BLOCKSIZE; pos.Z++)
 		for (pos.Y = 0; pos.Y < MAP_BLOCKSIZE; pos.Y++)
@@ -272,7 +274,6 @@ void LBMManager::applyLBMs(ServerEnvironment *env, MapBlock *block,
 			n = block->getNodeNoCheck(pos);
 			c = n.getContent();
 
-			// If content_t are not matching perform an LBM lookup
 			if (previous_c != c) {
 				lbm_list = it->second.lookup(c);
 				previous_c = c;
@@ -792,11 +793,9 @@ void ServerEnvironment::loadDefaultMeta()
 struct ActiveABM
 {
 	ActiveBlockModifier *abm;
-	int chance;
 	std::vector<content_t> required_neighbors;
-	bool check_required_neighbors; // false if required_neighbors is known to be empty
-	s16 min_y;
-	s16 max_y;
+	int chance;
+	s16 min_y, max_y;
 };
 
 #define CONTENT_TYPE_CACHE_MAX 64
@@ -812,14 +811,14 @@ public:
 		bool use_timers):
 		m_env(env)
 	{
-		if(dtime_s < 0.001)
+		if (dtime_s < 0.001f)
 			return;
 		const NodeDefManager *ndef = env->getGameDef()->ndef();
 		for (ABMWithState &abmws : abms) {
 			ActiveBlockModifier *abm = abmws.abm;
 			float trigger_interval = abm->getTriggerInterval();
-			if(trigger_interval < 0.001)
-				trigger_interval = 0.001;
+			if (trigger_interval < 0.001f)
+				trigger_interval = 0.001f;
 			float actual_interval = dtime_s;
 			if (use_timers) {
 				abmws.timer += dtime_s;
@@ -831,6 +830,7 @@ public:
 			float chance = abm->getTriggerChance();
 			if (chance == 0)
 				chance = 1;
+
 			ActiveABM aabm;
 			aabm.abm = abm;
 			if (abm->getSimpleCatchUp()) {
@@ -848,28 +848,24 @@ public:
 			aabm.max_y = abm->getMaxY();
 
 			// Trigger neighbors
-			const std::vector<std::string> &required_neighbors_s =
-				abm->getRequiredNeighbors();
-			for (const std::string &required_neighbor_s : required_neighbors_s) {
-				ndef->getIds(required_neighbor_s, aabm.required_neighbors);
-			}
-			aabm.check_required_neighbors = !required_neighbors_s.empty();
+			for (const auto &s : abm->getRequiredNeighbors())
+				ndef->getIds(s, aabm.required_neighbors);
+			SORT_AND_UNIQUE(aabm.required_neighbors);
 
 			// Trigger contents
-			const std::vector<std::string> &contents_s = abm->getTriggerContents();
-			for (const std::string &content_s : contents_s) {
 			std::vector<content_t> ids;
-				ndef->getIds(content_s, ids);
+			for (const auto &s : abm->getTriggerContents())
+				ndef->getIds(s, ids);
+			SORT_AND_UNIQUE(ids);
 			for (content_t c : ids) {
 				if (c >= m_aabms.size())
-						m_aabms.resize(c + 256, NULL);
+					m_aabms.resize(c + 256, nullptr);
 				if (!m_aabms[c])
 					m_aabms[c] = new std::vector<ActiveABM>;
 				m_aabms[c]->push_back(aabm);
 			}
 		}
 	}
-	}
 
 	~ABMHandler()
 	{
@@ -967,7 +963,7 @@ public:
 					continue;
 
 				// Check neighbors
-				if (aabm.check_required_neighbors) {
+				if (!aabm.required_neighbors.empty()) {
 					v3s16 p1;
 					for(p1.X = p0.X-1; p1.X <= p0.X+1; p1.X++)
 					for(p1.Y = p0.Y-1; p1.Y <= p0.Y+1; p1.Y++)

src/serverenvironment.h

@@ -90,7 +90,7 @@ struct ABMWithState
 struct LoadingBlockModifierDef
 {
 	// Set of contents to trigger on
-	std::set<std::string> trigger_contents;
+	std::vector<std::string> trigger_contents;
 	std::string name;
 	bool run_at_every_load = false;
 
@@ -100,19 +100,25 @@ struct LoadingBlockModifierDef
 			MapNode n, float dtime_s) {};
 };
 
-struct LBMContentMapping
+class LBMContentMapping
 {
-	typedef std::unordered_map<content_t, std::vector<LoadingBlockModifierDef *>> lbm_map;
-	lbm_map map;
+public:
+	typedef std::vector<LoadingBlockModifierDef*> lbm_vector;
+	typedef std::unordered_map<content_t, lbm_vector> lbm_map;
 
-	std::vector<LoadingBlockModifierDef *> lbm_list;
-
-	// Needs to be separate method (not inside destructor),
-	// because the LBMContentMapping may be copied and destructed
-	// many times during operation in the lbm_lookup_map.
-	void deleteContents();
+	LBMContentMapping() = default;
 	void addLBM(LoadingBlockModifierDef *lbm_def, IGameDef *gamedef);
 	const lbm_map::mapped_type *lookup(content_t c) const;
+	const lbm_vector &getList() const { return lbm_list; }
+
+	// This struct owns the LBM pointers.
+	~LBMContentMapping();
+	DISABLE_CLASS_COPY(LBMContentMapping);
+	ALLOW_CLASS_MOVE(LBMContentMapping);
+
+private:
+	lbm_vector lbm_list;
+	lbm_map map;
 };
 
 class LBMManager

src/util/basic_macros.h

@@ -28,6 +28,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 // Requires <algorithm>
 #define CONTAINS(c, v) (std::find((c).begin(), (c).end(), (v)) != (c).end())
 
+// Requires <algorithm>
+#define SORT_AND_UNIQUE(c) do { \
+	std::sort((c).begin(), (c).end()); \
+	(c).erase(std::unique((c).begin(), (c).end()), (c).end()); \
+	} while (0)
+
 // To disable copy constructors and assignment operations for some class
 // 'Foobar', add the macro DISABLE_CLASS_COPY(Foobar) in the class definition.
 // Note this also disables copying for any classes derived from 'Foobar' as well