Bulk LBMs (#14954)

src/script/cpp_api/s_env.cpp

@@ -111,10 +111,11 @@ public:
 		this->name = name;
 	}
 
-	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n, float dtime_s)
+	virtual void trigger(ServerEnvironment *env, MapBlock *block,
+		const std::unordered_set<v3s16> &positions, float dtime_s)
 	{
 		auto *script = env->getScriptIface();
-		script->triggerLBM(m_id, p, n, dtime_s);
+		script->triggerLBM(m_id, block, positions, dtime_s);
 	}
 };
 
@@ -291,10 +292,6 @@ void ScriptApiEnv::readLBMs()
 		bool run_at_every_load = getboolfield_default(L, current_lbm,
 			"run_at_every_load", false);
 
-		lua_getfield(L, current_lbm, "action");
-		luaL_checktype(L, current_lbm + 1, LUA_TFUNCTION);
-		lua_pop(L, 1);
-
 		LuaLBM *lbm = new LuaLBM(id, trigger_contents, name,
 			run_at_every_load);
 
@@ -462,34 +459,29 @@ void ScriptApiEnv::triggerABM(int id, v3s16 p, MapNode n,
 	lua_pop(L, 1); // Pop error handler
 }
 
-void ScriptApiEnv::triggerLBM(int id, v3s16 p,
-	const MapNode n, const float dtime_s)
+void ScriptApiEnv::triggerLBM(int id, MapBlock *block,
+		const std::unordered_set<v3s16> &positions, float dtime_s)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
 	int error_handler = PUSH_ERROR_HANDLER(L);
 
-	// Get registered_lbms
+	const v3s16 pos_of_block = block->getPosRelative();
+
+	// Get core.run_lbm
 	lua_getglobal(L, "core");
-	lua_getfield(L, -1, "registered_lbms");
-	luaL_checktype(L, -1, LUA_TTABLE);
+	lua_getfield(L, -1, "run_lbm");
+	luaL_checktype(L, -1, LUA_TFUNCTION);
 	lua_remove(L, -2); // Remove core
 
-	// Get registered_lbms[m_id]
+	// Call it
 	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_createtable(L, positions.size(), 0);
+	int i = 1;
+	for (auto &p : positions) {
+		push_v3s16(L, pos_of_block + p);
+		lua_rawseti(L, -2, i++);
+	}
 	lua_pushnumber(L, dtime_s);
 
 	int result = lua_pcall(L, 3, 0, error_handler);

src/script/cpp_api/s_env.h

@@ -26,6 +26,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <vector>
 
 class ServerEnvironment;
+class MapBlock;
 struct ScriptCallbackState;
 
 class ScriptApiEnv : virtual public ScriptApiBase
@@ -61,7 +62,8 @@ public:
 	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);
+	void triggerLBM(int id, MapBlock *block,
+		const std::unordered_set<v3s16> &positions, float dtime_s);
 
 private:
 	void readABMs();

src/serverenvironment.cpp

@@ -257,40 +257,73 @@ void LBMManager::applyLBMs(ServerEnvironment *env, MapBlock *block,
 	FATAL_ERROR_IF(!m_query_mode,
 		"attempted to query on non fully set up LBMManager");
 
-	const v3s16 pos_of_block = block->getPosRelative();
-	v3s16 pos;
-	MapNode n;
-	content_t c;
-	auto it = getLBMsIntroducedAfter(stamp);
+	// Collect a list of all LBMs and associated positions
+	struct LBMToRun {
+		std::unordered_set<v3s16> p; // node positions
+		std::unordered_set<LoadingBlockModifierDef*> l;
+	};
+	std::unordered_map<content_t, LBMToRun> to_run;
+
 	// 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 lookup result since it has a high performance penalty.
+	for (auto it = getLBMsIntroducedAfter(stamp); it != m_lbm_lookup.end(); ++it) {
+		v3s16 pos;
+		content_t c;
+
+		// Cache previous lookups since it has a high performance penalty.
 		content_t previous_c = CONTENT_IGNORE;
 		const LBMContentMapping::lbm_vector *lbm_list = nullptr;
+		LBMToRun *batch = nullptr;
 
 		for (pos.Z = 0; pos.Z < MAP_BLOCKSIZE; pos.Z++)
 		for (pos.Y = 0; pos.Y < MAP_BLOCKSIZE; pos.Y++)
 		for (pos.X = 0; pos.X < MAP_BLOCKSIZE; pos.X++) {
-			n = block->getNodeNoCheck(pos);
-			c = n.getContent();
+			c = block->getNodeNoCheck(pos).getContent();
 
+			bool c_changed = false;
 			if (previous_c != c) {
+				c_changed = true;
 				lbm_list = it->second.lookup(c);
+				batch = &to_run[c];
 				previous_c = c;
 			}
 
 			if (!lbm_list)
 				continue;
-			for (auto lbmdef : *lbm_list) {
-				lbmdef->trigger(env, pos + pos_of_block, n, dtime_s);
-				if (block->isOrphan())
-					return;
-				n = block->getNodeNoCheck(pos);
-				if (n.getContent() != c)
-					break; // The node was changed and the LBMs no longer apply
+			batch->p.insert(pos);
+			if (c_changed) {
+				batch->l.insert(lbm_list->begin(), lbm_list->end());
+			} else {
+				// we were here before so the list must be filled
+				assert(!batch->l.empty());
 			}
 		}
 	}
+
+	// Actually run them
+	bool first = true;
+	for (auto &[c, batch] : to_run) {
+		for (auto &lbm_def : batch.l) {
+			if (!first) {
+				// The fun part: since any LBM call can change the nodes inside of he
+				// block, we have to recheck the positions to see if the wanted node
+				// is still there.
+				// Note that we don't rescan the whole block, we don't want to include new changes.
+				for (auto it2 = batch.p.begin(); it2 != batch.p.end(); ) {
+					if (block->getNodeNoCheck(*it2).getContent() != c)
+						it2 = batch.p.erase(it2);
+					else
+						++it2;
+				}
+			}
+			first = false;
+
+			if (batch.p.empty())
+				break;
+			lbm_def->trigger(env, block, batch.p, dtime_s);
+			if (block->isOrphan())
+				return;
+		}
+	}
 }
 
 /*

src/serverenvironment.h

@@ -96,8 +96,13 @@ struct LoadingBlockModifierDef
 
 	virtual ~LoadingBlockModifierDef() = default;
 
-	virtual void trigger(ServerEnvironment *env, v3s16 p,
-			MapNode n, float dtime_s) {};
+	/// @brief Called to invoke LBM
+	/// @param env environment
+	/// @param block the block in question
+	/// @param positions set of node positions (block-relative!)
+	/// @param dtime_s game time since last deactivation
+	virtual void trigger(ServerEnvironment *env, MapBlock *block,
+		const std::unordered_set<v3s16> &positions, float dtime_s) {};
 };
 
 class LBMContentMapping