GeoIP mmdb format

complete document MaxMind DB File Format SpecificationDescription

here is only how convert trie tree to array

0100, 1011 -> trie

trie -> array
left is 0, right is 1
value is index of array

left	right	byte/index
2	4	0-1
null	6	2-3
8	null	4-5
10	null	6-7
null	12	8-9
14	null	10-11
null	16	11-12
end	null	12-13
null	end	13-14

array: [2,4,null,6,8,null,10,null,null,12,14,null,null,16,end,null,null,end]

for example:

index 1:
next left index 2 is null, so 00* is not exist
next right index 2+1 = 3 is not null, continue search until end or null

this is one byte as one child, but one byte max is 255, if node more than 255, we can use multiple byte as one child