Add minetest.bulk_swap_node (#15043)

Co-authored-by: sfan5 <sfan5@live.de>

builtin/emerge/env.lua

@@ -23,6 +23,8 @@ core.add_node = core.set_node
 -- we don't deal with metadata currently
 core.swap_node = core.set_node
 
+core.bulk_swap_node = core.bulk_set_node
+
 function core.remove_node(pos)
 	return core.vmanip:set_node_at(pos, {name="air"})
 end

doc/lua_api.md

@@ -6145,6 +6145,8 @@ Environment access
 * `minetest.swap_node(pos, node)`
     * Swap node at position with another.
     * This keeps the metadata intact and will not run con-/destructor callbacks.
+* `minetest.bulk_swap_node({pos1, pos2, pos3, ...}, node)`
+    * Equivalent to `minetest.swap_node` but in bulk.
 * `minetest.remove_node(pos)`: Remove a node
     * Equivalent to `minetest.set_node(pos, {name="air"})`, but a bit faster.
 * `minetest.get_node(pos)`

games/devtest/mods/benchmarks/init.lua

@@ -154,3 +154,36 @@ minetest.register_chatcommand("bench_bulk_get_node", {
 		return true, msg
 	end,
 })
+
+minetest.register_chatcommand("bench_bulk_swap_node", {
+	params = "",
+	description = "Benchmark: Bulk-swap 99×99×99 stone nodes",
+	func = function(name, param)
+		local player = minetest.get_player_by_name(name)
+		if not player then
+			return false, "No player."
+		end
+		local pos_list = get_positions_cube(player:get_pos())
+
+		minetest.chat_send_player(name, "Benchmarking minetest.bulk_swap_node. Warming up ...")
+
+		-- warm up because first execution otherwise becomes
+		-- significantly slower
+		minetest.bulk_swap_node(pos_list, {name = "mapgen_stone"})
+
+		minetest.chat_send_player(name, "Warming up finished, now benchmarking ...")
+
+		local start_time = minetest.get_us_time()
+		for i=1,#pos_list do
+			minetest.swap_node(pos_list[i], {name = "mapgen_stone"})
+		end
+		local middle_time = minetest.get_us_time()
+		minetest.bulk_swap_node(pos_list, {name = "mapgen_stone"})
+		local end_time = minetest.get_us_time()
+		local msg = string.format("Benchmark results: minetest.swap_node loop: %.2f ms; minetest.bulk_swap_node: %.2f ms",
+			((middle_time - start_time)) / 1000,
+			((end_time - middle_time)) / 1000
+		)
+		return true, msg
+	end,
+})

src/script/lua_api/l_env.cpp

@@ -253,6 +253,31 @@ int ModApiEnv::l_swap_node(lua_State *L)
 	return 1;
 }
 
+// bulk_swap_node([pos1, pos2, ...], node)
+// pos = {x=num, y=num, z=num}
+int ModApiEnv::l_bulk_swap_node(lua_State *L)
+{
+	GET_ENV_PTR;
+
+	luaL_checktype(L, 1, LUA_TTABLE);
+
+	s32 len = lua_objlen(L, 1);
+
+	MapNode n = readnode(L, 2);
+
+	// Do it
+	bool succeeded = true;
+	for (s32 i = 1; i <= len; i++) {
+		lua_rawgeti(L, 1, i);
+		if (!env->swapNode(read_v3s16(L, -1), n))
+			succeeded = false;
+		lua_pop(L, 1);
+	}
+
+	lua_pushboolean(L, succeeded);
+	return 1;
+}
+
 // get_node_raw(x, y, z) -> content, param1, param2, pos_ok
 int ModApiEnv::l_get_node_raw(lua_State *L)
 {
@@ -1377,6 +1402,7 @@ void ModApiEnv::Initialize(lua_State *L, int top)
 	API_FCT(bulk_set_node);
 	API_FCT(add_node);
 	API_FCT(swap_node);
+	API_FCT(bulk_swap_node);
 	API_FCT(add_item);
 	API_FCT(remove_node);
 	API_FCT(get_node_raw);

src/script/lua_api/l_env.h

@@ -65,6 +65,10 @@ private:
 	// pos = {x=num, y=num, z=num}
 	static int l_bulk_set_node(lua_State *L);
 
+	// bulk_swap_node([pos1, pos2, ...], node)
+	// pos = {x=num, y=num, z=num}
+	static int l_bulk_swap_node(lua_State *L);
+
 	static int l_add_node(lua_State *L);
 
 	// remove_node(pos)