Revert change to node pos hashes, and rewrite trackdb to use individual coordinates

The precision of integers was not sufficient for saving pos node hashes in most cases, leading to strange bugs.
This fixes broken ATC rails, broken LuaAutomation stuff and trackdb on Windows.
Probably also fixes trains randomly stopping.

1 files changed, 50 insertions, 42 deletions

diff --git a/advtrains/advtrains/nodedb.lua b/advtrains/advtrains/nodedb.lua
index e3ed56d..ddd1a67 100644
--- a/advtrains/advtrains/nodedb.lua
+++ b/advtrains/advtrains/nodedb.lua
@@ -2,42 +2,22 @@
 --database of all nodes that have 'save_in_nodedb' field set to true in node definition
 
 
-
 --serialization format:
---(6byte poshash) (2byte contentid)
+--(2byte z) (2byte y) (2byte x) (2byte contentid)
 --contentid := (14bit nodeid, 2bit param2)
 
-local function hash_to_bytes(x)
-	local aH = math.floor(x / 1099511627776) % 256;
-	local aL = math.floor(x /    4294967296) % 256;
-	local bH = math.floor(x /      16777216) % 256;
-	local bL = math.floor(x /         65536) % 256;
-	local cH = math.floor(x /           256) % 256;
-	local cL = math.floor(x                ) % 256;
-	return(string.char(aH, aL, bH, bL, cH, cL));
-end
-local function cid_to_bytes(x)
+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_hash(bytes)
-	local t={string.byte(bytes,1,-1)}
-	local n = 
-		t[1] * 1099511627776 +
-		t[2] *    4294967296 +
-		t[3] *      16777216 +
-		t[4] *         65536 +
-		t[5] *           256 +
-		t[6]
-    return n
-end
-local function bytes_to_cid(bytes)
+local function bytes_to_int(bytes)
 	local t={string.byte(bytes,1,-1)}
 	local n = 
 		t[1] *           256 +
 		t[2]
-    return n
+    return n-32768
 end
 local function l2b(x)
 	return x%4
@@ -51,25 +31,50 @@ local ndb={}
 local ndb_nodeids={}
 local ndb_nodes={}
 
+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
+
+
 --load
 --nodeids get loaded by advtrains init.lua and passed here
 function ndb.load_data(data)
 	ndb_nodeids = data and data.nodeids or {}
 end
 
-local path=minetest.get_worldpath().."/advtrains_ndb"
+local path=minetest.get_worldpath().."/advtrains_ndb2"
 
 local file, err = io.open(path, "r")
 if not file then
 	atprint("load ndb failed: ", err or "Unknown Error")
 else
 	local cnt=0
-	local hst=file:read(6)
+	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 and #hst==6 and cid and #cid==2 do
-		ndb_nodes[bytes_to_hash(hst)]=bytes_to_cid(cid)
+	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
+		ndbset(bytes_to_int(hst_x), bytes_to_int(hst_y), bytes_to_int(hst_z), bytes_to_int(cid))
 		cnt=cnt+1
-		hst=file:read(6)
+		hst_z=file:read(2)
+		hst_y=file:read(2)
+		hst_x=file:read(2)
 		cid=file:read(2)
 	end
 	atprint("nodedb: read", cnt, "nodes.")
@@ -80,11 +85,17 @@ end
 function ndb.save_data()
 	local file, err = io.open(path, "w")
 	if not file then
-		atprint("load ndb failed: ", err or "Unknown Error")
+		atprint("save ndb failed: ", err or "Unknown Error")
 	else
-		for hash, cid in pairs(ndb_nodes) do
-			file:write(hash_to_bytes(hash))
-			file:write(cid_to_bytes(cid))
+		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
@@ -98,7 +109,7 @@ function ndb.get_node_or_nil(pos)
 		return node
 	else
 		--maybe we have the node in the database...
-		local cid=ndb_nodes[minetest.hash_node_position(pos)]
+		local cid=ndbget(pos.x, pos.y, pos.z)
 		if cid then
 			local nodeid = ndb_nodeids[u14b(cid)]
 			if nodeid then
@@ -136,19 +147,16 @@ function ndb.update(pos, pnode)
 			nid=#ndb_nodeids+1
 			ndb_nodeids[nid]=node.name
 		end
-		local hash = minetest.hash_node_position(pos)
-		ndb_nodes[hash] = (nid * 4) + (l2b(node.param2 or 0))
+		ndbset(pos.x, pos.y, pos.z, (nid * 4) + (l2b(node.param2 or 0)) )
 		--atprint("nodedb: updating node", pos, "stored nid",nid,"assigned",ndb_nodeids[nid],"resulting cid",ndb_nodes[hash])
 	else
 		--at this position there is no longer a node that needs to be tracked.
-		local hash = minetest.hash_node_position(pos)
-		ndb_nodes[hash] = nil
+		ndbset(pos.x, pos.y, pos.z, nil)
 	end
 end
 
 function ndb.clear(pos)
-	local hash = minetest.hash_node_position(pos)
-	ndb_nodes[hash] = nil
+	ndbset(pos.x, pos.y, pos.z, nil)
 end
 
 
@@ -195,7 +203,7 @@ minetest.register_abm({
         nodenames = {"group:save_in_nodedb"},
         run_at_every_load = true,
         action = function(pos, node)
-			local cid=ndb_nodes[minetest.hash_node_position(pos)]
+			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)]