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bug fix for hash-based and path-based trie demo code #7

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69 changes: 36 additions & 33 deletions trie/hash.py
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,10 +14,13 @@ def __init__(self, kind, data):
self.kind = kind
self.data = data

def hash(self):
return hash_func(self.data)

def get_nbit(key, pos):
b = pos // 8
return (key[b] >> (pos % 8)) % 2
b = pos >> 3 # pos // 8
shift = 7 - (pos & 7) # 7 - (pos % 8)
return (key[b] >> shift) & 1


# a), initial tree
Expand Down Expand Up @@ -52,13 +55,13 @@ def __init__(self):

def __createInternal(self, value):
node = Node(KIND_INTERNAL, value)
key = hash_func(value)
key = node.hash()
self.kv[key] = node
return key, node

def __createLeaf(self, key, value):
node = Node(KIND_LEAF, key + value) # TODO: only store the part of the key not used in path
hkey = hash_func(key + value)
hkey = node.hash()
self.kv[hkey] = node
return hkey, node

Expand All @@ -83,12 +86,12 @@ def put(self, key, value):
if get_nbit(key, depth) != get_nbit(existing_leaf_key, depth):
break

if get_nbit(key, depth) == 0:
if get_nbit(key, common) == 0:
inode_data = leaf_hash + node_key
else:
inode_data = node_key + leaf_hash
inode_key, _ = self.__createInternal(inode_data)
for i in range(common-1, depth, -1):
for i in range(common-1, depth - 1, -1):
if get_nbit(key, i) == 0:
inode_data = inode_key + KEY_NIL
else:
Expand Down Expand Up @@ -141,35 +144,35 @@ def setRoot(self, root):


t = Tree()
t.put(b'\2'+b'\1'*31, b'\0')
assert t.get(b'\2'+b'\1'*31) == b'\0'
t.put(b'\0'+b'\1'*31, b'\1')
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\1'
t.put(b'\3'+b'\1'*31, b'\2')
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\1'
assert t.get(b'\3'+b'\1'*31) == b'\2'
t.put(b'\x40'+b'\1'*31, b'\0') # b'\x40' -> 0100 0000
assert t.get(b'\x40'+b'\1'*31) == b'\0'
t.put(b'\x00'+b'\1'*31, b'\1') # b'\x00' -> 0000 0000
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\1'
t.put(b'\xc0'+b'\1'*31, b'\2') # b'\xc0' -> 1100 0000
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\1'
assert t.get(b'\xc0'+b'\1'*31) == b'\2'
root = t.root
t.put(b'\131'+b'\1'*31, b'\3')
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\1'
assert t.get(b'\3'+b'\1'*31) == b'\2'
assert t.get(b'\131'+b'\1'*31) == b'\3'
t.put(b'\x60'+b'\1'*31, b'\3') # b'\x60' -> 0110 0000
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\1'
assert t.get(b'\xc0'+b'\1'*31) == b'\2'
assert t.get(b'\x60'+b'\1'*31) == b'\3'
t.setRoot(root)
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\1'
assert t.get(b'\3'+b'\1'*31) == b'\2'
assert t.get(b'\131'+b'\1'*31) == None
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\1'
assert t.get(b'\xc0'+b'\1'*31) == b'\2'
assert t.get(b'\x60'+b'\1'*31) == None

# test multi-version
t.put(b'\0'+b'\1'*31, b'\3')
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\3'
assert t.get(b'\3'+b'\1'*31) == b'\2'
assert t.get(b'\131'+b'\1'*31) == None
t.put(b'\x00'+b'\1'*31, b'\3')
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\3'
assert t.get(b'\xc0'+b'\1'*31) == b'\2'
assert t.get(b'\x60'+b'\1'*31) == None
t.setRoot(root)
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\1'
assert t.get(b'\3'+b'\1'*31) == b'\2'
assert t.get(b'\131'+b'\1'*31) == None
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\1'
assert t.get(b'\xc0'+b'\1'*31) == b'\2'
assert t.get(b'\x60'+b'\1'*31) == None
71 changes: 39 additions & 32 deletions trie/path.py
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,8 +19,9 @@ def hash(self):
return hash_func(self.data)

def get_nbit(key, pos):
b = pos // 8
return (key[b] >> (pos % 8)) % 2
b = pos >> 3 # pos // 8
shift = 7 - (pos & 7) # 7 - (pos % 8)
return (key[b] >> shift) & 1

# a), initial tree
# root=internal('0'*32 + '0'*32)
Expand Down Expand Up @@ -57,9 +58,11 @@ def get_nbit(key, pos):
# n0=leaf(h0+d0), n1=leaf(h1+d1)
# key '' => root
# key '0' => inode0
# key '00' => n1
# key '01' => inode1
# key '010' => n1
# key '011' => n0
# key '010' => n0
# key '011' => n3
# key '1' => n2

class Tree:
def __init__(self, kv=None):
Expand Down Expand Up @@ -195,46 +198,50 @@ def root(self):
def test_tree(tree_func):
t = tree_func()
t1 = hash.Tree()
t.put(b'\2'+b'\1'*31, b'\0')
t1.put(b'\2'+b'\1'*31, b'\0')
assert t.get(b'\2'+b'\1'*31) == b'\0'
# b'\x40' -> 0100 0000
t.put(b'\x40'+b'\1'*31, b'\0')
t1.put(b'\x40'+b'\1'*31, b'\0')
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.root == t1.root
t.put(b'\0'+b'\1'*31, b'\1')
t1.put(b'\0'+b'\1'*31, b'\1')
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\1'
# b'\x00' -> 0000 0000
t.put(b'\x00'+b'\1'*31, b'\1')
t1.put(b'\x00'+b'\1'*31, b'\1')
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\1'
assert t.root == t1.root
t.put(b'\3'+b'\1'*31, b'\2')
t1.put(b'\3'+b'\1'*31, b'\2')
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\1'
assert t.get(b'\3'+b'\1'*31) == b'\2'
# b'\xc0' -> 1100 0000
t.put(b'\xc0'+b'\1'*31, b'\2')
t1.put(b'\xc0'+b'\1'*31, b'\2')
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\1'
assert t.get(b'\xc0'+b'\1'*31) == b'\2'
snapshot = dict(t.kv)
root1 = t1.root
assert t.root == t1.root
t.put(b'\131'+b'\1'*31, b'\3')
t1.put(b'\131'+b'\1'*31, b'\3')
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\1'
assert t.get(b'\3'+b'\1'*31) == b'\2'
assert t.get(b'\131'+b'\1'*31) == b'\3'
# b'\x60' -> 0110 0000
t.put(b'\x60'+b'\1'*31, b'\3')
t1.put(b'\x60'+b'\1'*31, b'\3')
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\1'
assert t.get(b'\xc0'+b'\1'*31) == b'\2'
assert t.get(b'\x60'+b'\1'*31) == b'\3'
assert t.root == t1.root

t = tree_func(snapshot)
t1.setRoot(root1)
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\1'
assert t.get(b'\3'+b'\1'*31) == b'\2'
assert t.get(b'\131'+b'\1'*31) == None
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\1'
assert t.get(b'\xc0'+b'\1'*31) == b'\2'
assert t.get(b'\x60'+b'\1'*31) == None
assert t.root == t1.root

# test multi-version
t.put(b'\0'+b'\1'*31, b'\3')
t1.put(b'\0'+b'\1'*31, b'\3')
assert t.get(b'\2'+b'\1'*31) == b'\0'
assert t.get(b'\0'+b'\1'*31) == b'\3'
assert t.get(b'\3'+b'\1'*31) == b'\2'
assert t.get(b'\131'+b'\1'*31) == None
t.put(b'\x00'+b'\1'*31, b'\3')
t1.put(b'\x00'+b'\1'*31, b'\3')
assert t.get(b'\x40'+b'\1'*31) == b'\0'
assert t.get(b'\x00'+b'\1'*31) == b'\3'
assert t.get(b'\xc0'+b'\1'*31) == b'\2'
assert t.get(b'\x60'+b'\1'*31) == None
assert t.root == t1.root

test_tree(Tree)
Expand Down