Squashed 'advtrains/' content from commit 3256c27

git-subtree-dir: advtrains
git-subtree-split: 3256c2778d626548541bcdfabf3026f781a2287c

1 files changed, 343 insertions, 0 deletions

diff --git a/advtrains/nodedb.lua b/advtrains/nodedb.lua
new file mode 100644
index 0000000..03a5a2d
--- /dev/null
+++ b/advtrains/nodedb.lua
@@ -0,0 +1,343 @@
+--nodedb.lua
+--database of all nodes that have 'save_in_at_nodedb' field set to true in node definition
+
+
+--serialization format:
+--(2byte z) (2byte y) (2byte x) (2byte contentid)
+--contentid := (14bit nodeid, 2bit param2)
+
+local function int_to_bytes(i)
+	local x=i+32768--clip to positive integers
+	local cH = math.floor(x /           256) % 256;
+	local cL = math.floor(x                ) % 256;
+	return(string.char(cH, cL));
+end
+local function bytes_to_int(bytes)
+	local t={string.byte(bytes,1,-1)}
+	local n = 
+		t[1] *           256 +
+		t[2]
+    return n-32768
+end
+local function l2b(x)
+	return x%4
+end
+local function u14b(x)
+	return math.floor(x/4)
+end
+local ndb={}
+
+--local variables for performance
+local ndb_nodeids={}
+local ndb_nodes={}
+local ndb_ver
+
+local function ndbget(x,y,z)
+	local ny=ndb_nodes[y]
+	if ny then
+		local nx=ny[x]
+		if nx then
+			return nx[z]
+		end
+	end
+	return nil
+end
+local function ndbset(x,y,z,v)
+	if not ndb_nodes[y] then
+		ndb_nodes[y]={}
+	end
+	if not ndb_nodes[y][x] then
+		ndb_nodes[y][x]={}
+	end
+	ndb_nodes[y][x][z]=v
+end
+
+
+local path=minetest.get_worldpath()..DIR_DELIM.."advtrains_ndb2"
+--load
+--nodeids get loaded by advtrains init.lua and passed here
+function ndb.load_data(data)
+	ndb_nodeids = data and data.nodeids or {}
+	ndb_ver = data and data.ver or 0
+	if ndb_ver < 1 then
+		for k,v in pairs(ndb_nodeids) do
+			if v == "advtrains:dtrack_xing4590_st" then
+				cidDepr = k
+			elseif v == "advtrains:dtrack_xing90plusx_45l" then
+				cidNew = k
+			end
+		end
+	end
+	local file, err = io.open(path, "rb")
+	if not file then
+		atwarn("Couldn't load the node database: ", err or "Unknown Error")
+	else
+		local cnt=0
+		local hst_z=file:read(2)
+		local hst_y=file:read(2)
+		local hst_x=file:read(2)
+		local cid=file:read(2)
+		while hst_z and hst_y and hst_x and cid and #hst_z==2 and #hst_y==2 and #hst_x==2 and #cid==2 do
+			if (ndb_ver < 1 and cid == cidDepr) then
+				cid = cidNew
+			end
+			ndbset(bytes_to_int(hst_x), bytes_to_int(hst_y), bytes_to_int(hst_z), bytes_to_int(cid))
+			cnt=cnt+1
+			hst_z=file:read(2)
+			hst_y=file:read(2)
+			hst_x=file:read(2)
+			cid=file:read(2)
+		end
+		atlog("nodedb: read", cnt, "nodes.")
+		file:close()
+	end
+	ndb_ver = 1
+end
+
+local windows_compat = false
+--save
+function ndb.save_data()
+	local tmppath = path.."~"
+	local file, err
+	if windows_compat then
+		-- open ndb file directly
+		file, err = io.open(path, "wb")
+	else
+		-- open another file next to it, then replace atomically
+		file, err = io.open(tmppath, "wb")
+	end
+	
+	if not file then
+		atwarn("Couldn't save the node database: ", err or "Unknown Error")
+	else
+		for y, ny in pairs(ndb_nodes) do
+			for x, nx in pairs(ny) do
+				for z, cid in pairs(nx) do
+					file:write(int_to_bytes(z))
+					file:write(int_to_bytes(y))
+					file:write(int_to_bytes(x))
+					file:write(int_to_bytes(cid))
+				end
+			end
+		end
+		file:close()
+	end
+	
+	if not windows_compat then
+		local success, msg = os.rename(tmppath, path)
+		--local success, msg = nil, "test"
+		-- for windows, this fails if the file already exists. Enable windows compatibility and directly write to path.
+		if not success then
+			atlog("Replacing the nodedb file atomically failed:",msg)
+			atlog("Switching to Windows mode (will directly overwrite the nodedb file from now on)")
+			windows_compat = true
+			os.remove(tmppath)
+			-- try again
+			ndb.save_data()
+		end
+	end
+	
+	return {nodeids = ndb_nodeids, ver = ndb_ver}
+end
+
+--function to get node. track database is not helpful here.
+function ndb.get_node_or_nil(pos)
+	-- FIX for bug found on linuxworks server:
+	-- a loaded node might get read before the LBM has updated its state, resulting in wrongly set signals and switches
+	-- -> Using the saved node prioritarily.
+	local node = ndb.get_node_raw(pos)
+	if node then
+		return node
+	else
+		--try reading the node from the map
+		return minetest.get_node_or_nil(pos)
+	end
+end
+function ndb.get_node(pos)
+	local n=ndb.get_node_or_nil(pos)
+	if not n then
+		return {name="ignore", param2=0}
+	end
+	return n
+end
+function ndb.get_node_raw(pos)
+	local cid=ndbget(pos.x, pos.y, pos.z)
+	if cid then
+		local nodeid = ndb_nodeids[u14b(cid)]
+		if nodeid then
+			return {name=nodeid, param2 = l2b(cid)}
+		end
+	end
+	return nil
+end
+
+
+function ndb.swap_node(pos, node, no_inval)
+	if minetest.get_node_or_nil(pos) then
+		minetest.swap_node(pos, node)
+	end
+	ndb.update(pos, node)
+end
+
+function ndb.update(pos, pnode)
+	local node = pnode or minetest.get_node_or_nil(pos)
+	if not node or node.name=="ignore" then return end
+	if minetest.registered_nodes[node.name] and minetest.registered_nodes[node.name].groups.save_in_at_nodedb then
+		local nid
+		for tnid, nname in pairs(ndb_nodeids) do
+			if nname==node.name then
+				nid=tnid
+			end
+		end
+		if not nid then
+			nid=#ndb_nodeids+1
+			ndb_nodeids[nid]=node.name
+		end
+		local resid = (nid * 4) + (l2b(node.param2 or 0))
+		ndbset(pos.x, pos.y, pos.z, resid )
+		--atdebug("nodedb: updating node", pos, "stored nid",nid,"assigned",ndb_nodeids[nid],"resulting cid",resid)
+		minetest.after(0, advtrains.invalidate_all_paths, pos)
+	else
+		--at this position there is no longer a node that needs to be tracked.
+		--atdebug("nodedb: updating node", pos, "cleared")
+		ndbset(pos.x, pos.y, pos.z, nil)
+	end
+end
+
+function ndb.clear(pos)
+	ndbset(pos.x, pos.y, pos.z, nil)
+end
+
+
+--get_node with pseudoload. now we only need track data, so we can use the trackdb as second fallback
+--nothing new will be saved inside the trackdb.
+--returns:
+--true, conn1, conn2, rely1, rely2, railheight   in case everything's right.
+--false  if it's not a rail or the train does not drive on this rail, but it is loaded or
+--nil    if the node is neither loaded nor in trackdb
+--the distraction between false and nil will be needed only in special cases.(train initpos)
+function advtrains.get_rail_info_at(pos, drives_on)
+	local rdp=advtrains.round_vector_floor_y(pos)
+	
+	local node=ndb.get_node_or_nil(rdp)
+	if not node then return end
+	
+	local nodename=node.name
+	if(not advtrains.is_track_and_drives_on(nodename, drives_on)) then
+		return false
+	end
+	local conns, railheight, tracktype=advtrains.get_track_connections(node.name, node.param2)
+	
+	return true, conns, railheight
+end
+
+ndb.run_lbm = function(pos, node)
+	return advtrains.pcall(function()
+		local cid=ndbget(pos.x, pos.y, pos.z)
+		if cid then
+			--if in database, detect changes and apply.
+			local nodeid = ndb_nodeids[u14b(cid)]
+			local param2 = l2b(cid)
+			if not nodeid then
+				--something went wrong
+				atwarn("Node Database corruption, couldn't determine node to set at", pos)
+				ndb.update(pos, node)
+			else
+				if (nodeid~=node.name or param2~=node.param2) then
+					atprint("nodedb: lbm replaced", pos, "with nodeid", nodeid, "param2", param2, "cid is", cid)
+					minetest.swap_node(pos, {name=nodeid, param2 = param2})
+					local ndef=minetest.registered_nodes[nodeid]
+					if ndef and ndef.on_updated_from_nodedb then
+						ndef.on_updated_from_nodedb(pos, node)
+					end
+					return true
+				end
+			end
+		else
+			--if not in database, take it.
+			--atlog("Node Database:", pos, "was not found in the database, have you used worldedit?")
+			ndb.update(pos, node)
+		end
+		return false
+	end)
+end
+
+
+minetest.register_lbm({
+        name = "advtrains:nodedb_on_load_update",
+        nodenames = {"group:save_in_at_nodedb"},
+        run_at_every_load = true,
+        run_on_every_load = true,
+        action = ndb.run_lbm,
+        interval=30,
+        chance=1,
+    })
+
+--used when restoring stuff after a crash
+ndb.restore_all = function()
+	--atlog("Updating the map from the nodedb, this may take a while")
+	local cnt=0
+	local dcnt=0
+	for y, ny in pairs(ndb_nodes) do
+		for x, nx in pairs(ny) do
+			for z, _ in pairs(nx) do
+				local pos={x=x, y=y, z=z}
+				local node=minetest.get_node_or_nil(pos)
+				if node then
+					local ori_ndef=minetest.registered_nodes[node.name]
+					local ndbnode=ndb.get_node_raw(pos)
+					if ori_ndef and ori_ndef.groups.save_in_at_nodedb then --check if this node has been worldedited, and don't replace then
+						if (ndbnode.name~=node.name or ndbnode.param2~=node.param2) then
+							minetest.swap_node(pos, ndbnode)
+							--atlog("Replaced",node.name,"@",pos,"with",ndbnode.name)
+							cnt=cnt+1
+						end
+					else
+						ndb.clear(pos)
+						dcnt=dcnt+1
+						--atlog("Found ghost node (former",ndbnode and ndbnode.name,") @",pos,"deleting")
+					end
+				end
+			end
+		end
+	end
+	local text="Restore node database: Replaced "..cnt.." nodes, removed "..dcnt.." ghost nodes."
+	atlog(text)
+	return text
+end
+    
+minetest.register_on_dignode(function(pos, oldnode, digger)
+	return advtrains.pcall(function()
+		ndb.clear(pos)
+	end)
+end)
+
+function ndb.get_nodes()
+	return ndb_nodes
+end
+function ndb.get_nodeids()
+	return ndb_nodeids
+end
+
+
+advtrains.ndb=ndb
+
+local ptime=0
+
+minetest.register_chatcommand("at_sync_ndb",
+	{
+        params = "", -- Short parameter description
+        description = "Write node db back to map and find ghost nodes", -- Full description
+        privs = {train_operator=true}, 
+        func = function(name, param)
+			return advtrains.pcall(function()
+				if os.time() < ptime+30 then
+					return false, "Please wait at least 30s from the previous execution of /at_restore_ndb!"
+				end
+				local text = ndb.restore_all()
+				ptime=os.time()
+				return true, text
+			end)
+        end,
+    })
+