Use a set for the block index to limit size

mosfet/protocol/managers.py

@@ -69,10 +69,10 @@ class ChunksManager:
 
                 for item_id, locations in chunk.sub_index.items():
                     if item_id not in self.index:
-                        self.index[item_id] = []
+                        self.index[item_id] = set()
                     for l in locations:
                         coords = (dx + l%16, dy + l//256, dz + l%256//16)
-                        self.index[item_id].append(coords)
+                        self.index[item_id].add(coords)
 
         #self.biomes[(chunk_packet.x, None, chunk_packet.z)] = chunk_packet.biomes # FIXME
         if self.loading:
@@ -118,8 +118,8 @@ class ChunksManager:
 
         if block in blocks.INDEXED_IDS:
             if block not in self.index:
-                self.index[block] = []
-            self.index[block].append((x, y, z))
+                self.index[block] = set()
+            self.index[block].add((x, y, z))
 
     def check_loaded(self, chunk_distance):
         num = (chunk_distance * 2 + 1) ** 2