Add minetest.register_lbm() to run code on block load only

src/environment.cpp

@@ -48,6 +48,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #define PP(x) "("<<(x).X<<","<<(x).Y<<","<<(x).Z<<")"
 
+#define LBM_NAME_ALLOWED_CHARS "abcdefghijklmnopqrstuvwxyz0123456789_:"
+
 Environment::Environment():
 	m_time_of_day_speed(0),
 	m_time_of_day(9000),
@@ -270,6 +272,223 @@ ABMWithState::ABMWithState(ActiveBlockModifier *abm_):
 	timer = myrand_range(minval, maxval);
 }
 
+/*
+	LBMManager
+*/
+
+void LBMContentMapping::deleteContents()
+{
+	for (std::vector<LoadingBlockModifierDef *>::iterator it = lbm_list.begin();
+			it != lbm_list.end(); ++it) {
+		delete *it;
+	}
+}
+
+void LBMContentMapping::addLBM(LoadingBlockModifierDef *lbm_def, IGameDef *gamedef)
+{
+	// Add the lbm_def to the LBMContentMapping.
+	// Unknown names get added to the global NameIdMapping.
+	INodeDefManager *nodedef = gamedef->ndef();
+
+	lbm_list.push_back(lbm_def);
+
+	for (std::set<std::string>::const_iterator it = lbm_def->trigger_contents.begin();
+			it != lbm_def->trigger_contents.end(); ++it) {
+		std::set<content_t> c_ids;
+		bool found = nodedef->getIds(*it, c_ids);
+		if (!found) {
+			content_t c_id = gamedef->allocateUnknownNodeId(*it);
+			if (c_id == CONTENT_IGNORE) {
+				// Seems it can't be allocated.
+				warningstream << "Could not internalize node name \"" << *it
+					<< "\" while loading LBM \"" << lbm_def->name << "\"." << std::endl;
+				continue;
+			}
+			c_ids.insert(c_id);
+		}
+
+		for (std::set<content_t>::const_iterator iit =
+				c_ids.begin(); iit != c_ids.end(); ++iit) {
+			content_t c_id = *iit;
+			map[c_id].push_back(lbm_def);
+		}
+	}
+}
+
+const std::vector<LoadingBlockModifierDef *> *
+		LBMContentMapping::lookup(content_t c) const
+{
+	container_map::const_iterator it = map.find(c);
+	if (it == map.end())
+		return NULL;
+	// This first dereferences the iterator, returning
+	// a std::vector<LoadingBlockModifierDef *>
+	// reference, then we convert it to a pointer.
+	return &(it->second);
+}
+
+LBMManager::~LBMManager()
+{
+	for (std::map<std::string, LoadingBlockModifierDef *>::iterator it =
+			m_lbm_defs.begin(); it != m_lbm_defs.end(); ++it) {
+		delete it->second;
+	}
+	for (lbm_lookup_map::iterator it = m_lbm_lookup.begin();
+			it != m_lbm_lookup.end(); ++it) {
+		(it->second).deleteContents();
+	}
+}
+
+void LBMManager::addLBMDef(LoadingBlockModifierDef *lbm_def)
+{
+	// Precondition, in query mode the map isn't used anymore
+	FATAL_ERROR_IF(m_query_mode == true,
+		"attempted to modify LBMManager in query mode");
+
+	if (!string_allowed(lbm_def->name, LBM_NAME_ALLOWED_CHARS)) {
+		throw ModError("Error adding LBM \"" + lbm_def->name +
+			"\": Does not follow naming conventions: "
+			"Only chararacters [a-z0-9_:] are allowed.");
+	}
+
+	m_lbm_defs[lbm_def->name] = lbm_def;
+}
+
+void LBMManager::loadIntroductionTimes(const std::string &times,
+		IGameDef *gamedef, u32 now)
+{
+	m_query_mode = true;
+
+	// name -> time map.
+	// Storing it in a map first instead of
+	// handling the stuff directly in the loop
+	// removes all duplicate entries.
+	// TODO make this std::unordered_map
+	std::map<std::string, u32> introduction_times;
+
+	/*
+	The introduction times string consists of name~time entries,
+	with each entry terminated by a semicolon. The time is decimal.
+	 */
+
+	size_t idx = 0;
+	size_t idx_new;
+	while ((idx_new = times.find(";", idx)) != std::string::npos) {
+		std::string entry = times.substr(idx, idx_new - idx);
+		std::vector<std::string> components = str_split(entry, '~');
+		if (components.size() != 2)
+			throw SerializationError("Introduction times entry \""
+				+ entry + "\" requires exactly one '~'!");
+		const std::string &name = components[0];
+		u32 time = from_string<u32>(components[1]);
+		introduction_times[name] = time;
+		idx = idx_new + 1;
+	}
+
+	// Put stuff from introduction_times into m_lbm_lookup
+	for (std::map<std::string, u32>::const_iterator it = introduction_times.begin();
+			it != introduction_times.end(); ++it) {
+		const std::string &name = it->first;
+		u32 time = it->second;
+
+		std::map<std::string, LoadingBlockModifierDef *>::iterator def_it =
+			m_lbm_defs.find(name);
+		if (def_it == m_lbm_defs.end()) {
+			// This seems to be an LBM entry for
+			// an LBM we haven't loaded. Discard it.
+			continue;
+		}
+		LoadingBlockModifierDef *lbm_def = def_it->second;
+		if (lbm_def->run_at_every_load) {
+			// This seems to be an LBM entry for
+			// an LBM that runs at every load.
+			// Don't add it just yet.
+			continue;
+		}
+
+		m_lbm_lookup[time].addLBM(lbm_def, gamedef);
+
+		// Erase the entry so that we know later
+		// what elements didn't get put into m_lbm_lookup
+		m_lbm_defs.erase(name);
+	}
+
+	// Now also add the elements from m_lbm_defs to m_lbm_lookup
+	// that weren't added in the previous step.
+	// They are introduced first time to this world,
+	// or are run at every load (introducement time hardcoded to U32_MAX).
+
+	LBMContentMapping &lbms_we_introduce_now = m_lbm_lookup[now];
+	LBMContentMapping &lbms_running_always = m_lbm_lookup[U32_MAX];
+
+	for (std::map<std::string, LoadingBlockModifierDef *>::iterator it =
+			m_lbm_defs.begin(); it != m_lbm_defs.end(); ++it) {
+		if (it->second->run_at_every_load) {
+			lbms_running_always.addLBM(it->second, gamedef);
+		} else {
+			lbms_we_introduce_now.addLBM(it->second, gamedef);
+		}
+	}
+
+	// Clear the list, so that we don't delete remaining elements
+	// twice in the destructor
+	m_lbm_defs.clear();
+}
+
+std::string LBMManager::createIntroductionTimesString()
+{
+	// Precondition, we must be in query mode
+	FATAL_ERROR_IF(m_query_mode == false,
+		"attempted to query on non fully set up LBMManager");
+
+	std::ostringstream oss;
+	for (lbm_lookup_map::iterator it = m_lbm_lookup.begin();
+			it != m_lbm_lookup.end(); ++it) {
+		u32 time = it->first;
+		std::vector<LoadingBlockModifierDef *> &lbm_list = it->second.lbm_list;
+		for (std::vector<LoadingBlockModifierDef *>::iterator iit = lbm_list.begin();
+				iit != lbm_list.end(); ++iit) {
+			// Don't add if the LBM runs at every load,
+			// then introducement time is hardcoded
+			// and doesn't need to be stored
+			if ((*iit)->run_at_every_load)
+				continue;
+			oss << (*iit)->name << "~" << time << ";";
+		}
+	}
+	return oss.str();
+}
+
+void LBMManager::applyLBMs(ServerEnvironment *env, MapBlock *block, u32 stamp)
+{
+	// Precondition, we need m_lbm_lookup to be initialized
+	FATAL_ERROR_IF(m_query_mode == false,
+		"attempted to query on non fully set up LBMManager");
+	v3s16 pos_of_block = block->getPosRelative();
+	v3s16 pos;
+	MapNode n;
+	content_t c;
+	lbm_lookup_map::const_iterator it = getLBMsIntroducedAfter(stamp);
+	for (pos.X = 0; pos.X < MAP_BLOCKSIZE; pos.X++)
+	for (pos.Y = 0; pos.Y < MAP_BLOCKSIZE; pos.Y++)
+	for (pos.Z = 0; pos.Z < MAP_BLOCKSIZE; pos.Z++)
+	{
+		n = block->getNodeNoEx(pos);
+		c = n.getContent();
+		for (LBMManager::lbm_lookup_map::const_iterator iit = it;
+				iit != m_lbm_lookup.end(); ++iit) {
+			const std::vector<LoadingBlockModifierDef *> *lbm_list =
+				iit->second.lookup(c);
+			if (!lbm_list)
+				continue;
+			for (std::vector<LoadingBlockModifierDef *>::const_iterator iit =
+					lbm_list->begin(); iit != lbm_list->end(); ++iit) {
+				(*iit)->trigger(env, pos + pos_of_block, n);
+			}
+		}
+	}
+}
+
 /*
 	ActiveBlockList
 */
@@ -505,6 +724,9 @@ void ServerEnvironment::saveMeta()
 	args.setU64("game_time", m_game_time);
 	args.setU64("time_of_day", getTimeOfDay());
 	args.setU64("last_clear_objects_time", m_last_clear_objects_time);
+	args.setU64("lbm_introduction_times_version", 1);
+	args.set("lbm_introduction_times",
+		m_lbm_mgr.createIntroductionTimesString());
 	args.writeLines(ss);
 	ss<<"EnvArgsEnd\n";
 
@@ -555,6 +777,26 @@ void ServerEnvironment::loadMeta()
 		// If missing, do as if clearObjects was never called
 		m_last_clear_objects_time = 0;
 	}
+
+	std::string lbm_introduction_times = "";
+	try {
+		u64 ver = args.getU64("lbm_introduction_times_version");
+		if (ver == 1) {
+			lbm_introduction_times = args.get("lbm_introduction_times");
+		} else {
+			infostream << "ServerEnvironment::loadMeta(): Non-supported"
+				<< " introduction time version " << ver << std::endl;
+		}
+	} catch (SettingNotFoundException &e) {
+		// No problem, this is expected. Just continue with an empty string
+	}
+	m_lbm_mgr.loadIntroductionTimes(lbm_introduction_times, m_gamedef, m_game_time);
+
+}
+
+void ServerEnvironment::loadDefaultMeta()
+{
+	m_lbm_mgr.loadIntroductionTimes("", m_gamedef, m_game_time);
 }
 
 struct ActiveABM
@@ -770,6 +1012,9 @@ void ServerEnvironment::activateBlock(MapBlock *block, u32 additional_dtime)
 	// Activate stored objects
 	activateObjects(block, dtime_s);
 
+	/* Handle LoadingBlockModifiers */
+	m_lbm_mgr.applyLBMs(this, block, stamp);
+
 	// Run node timers
 	std::map<v3s16, NodeTimer> elapsed_timers =
 		block->m_node_timers.step((float)dtime_s);
@@ -795,6 +1040,11 @@ void ServerEnvironment::addActiveBlockModifier(ActiveBlockModifier *abm)
 	m_abms.push_back(ABMWithState(abm));
 }
 
+void ServerEnvironment::addLoadingBlockModifierDef(LoadingBlockModifierDef *lbm)
+{
+	m_lbm_mgr.addLBMDef(lbm);
+}
+
 bool ServerEnvironment::setNode(v3s16 p, const MapNode &n)
 {
 	INodeDefManager *ndef = m_gamedef->ndef();