Implementation of a btree based merkle tree.  The original merkle tree would not scale out to a large number of keys due to the limitation of keeping the tree in main memory.  Therefore we will try and store the 
 
btree file:
file header: version:1, blocksize:32, freepointer:64, rootpointer:64,
freekeys1:64, freekeys2:64, freekeys3:64, freekeys4:64, freekeys5:64
reserved/bytes:
header size: 85
 
node:{0,m:32,[keyhash:32],[childhash:32,child:64]}
 
leaf:{1,m:32,[keyhash:32,keypointer:64,valhash:32]}
 
freenode:{2,nextpointer:64,0:(blocksize-9)}
 
for nodes:
blocksize = 1 + 4 + D*4 + (D+1)*12
D = (blocksize-17)/16
 
for leaves:
blocksize = 5 + D*16
D = (blocksize-5)/16
 
65521
 
 
 
key file:
 
[key\0,key\0,key\0]
 
keys allocation
 
l = 2**4
 
m = 2**64
 
 
 
header size = 85 + (√blocksize - 4)*8