def get_node_value(self, node, key):
_node_type = self.node_type(node)
if _node_type == 'Branch':
#key="", find
if not key:
return node[-1]
child = node[key[0]]
return self.get_node_value(self.decode(child), key[1:])
if _node_type == 'Blank':
return ""
#leaf node or extension node
original_key = encoding.terminator(encoding.hp_to_hex(node[0]), False)
if _node_type == "Leaf":
if key == original_key:
return node[1]
else:
return ""
if _node_type == "Extension":
#check new_key is in the prefix of key
if len(original_key) > len(key) or key[:len(original_key)] != original_key:
return ""
else:
return self.get_node_value(self.decode(node[1]), key[len(original_key):])
def _iter_subtree(self, node):
_node_type = self.node_type(node)
if _node_type == "Blank":
return {}
if _node_type == "Branch":
result = {}
for i in range(16):
res = self._iter_subtree(self.decode(node[i]))
for key, value in res.items():
#print("key:",key)
original_key = str(i) + "," + key
#print("ori:",original_key)
result[original_key] = value
if node[-1]:
result["16"] = node[-1]
return result
tmp = encoding.terminator(encoding.hp_to_hex(node[0]), False)
key = ",".join([str(t) for t in tmp])
if _node_type == "Extension":
res = self._iter_subtree(self.decode(node[1]))
if _node_type == "Leaf":
res = {"16": node[1]}
result = {}
for key2, value in res.items():
print('key:', key, "key2:", key2, "value:", value)
original_key = key + "," + key2
result[original_key] = value
return result
def node_type(self, node):
if len(node) == 17:
return "Branch"
elif len(node) == 2:
nib = encoding.hp_to_hex(node[0])
#print("nib",nib)
if nib[-1] == END:
return "Leaf"
else:
return "Extension"
elif node == "":
return "Blank"
else:
raise TypeError("There is no this node type!")
def search_prefix(self, node, prefix, curr_prefix):
_node_type = self.node_type(node)
print("type:", _node_type)
#check this type
#print("prefix:",prefix)
if not prefix:
return node, curr_prefix
if _node_type == "Blank":
return "", curr_prefix
if _node_type == "Branch":
if not prefix:
return node, curr_prefix
child = node[prefix[0]]
curr_prefix += [prefix[0]]
#print(self.decode(child))
node, curr_prefix = self.search_prefix(self.decode(child),
prefix[1:], curr_prefix)
return node, curr_prefix
#leaf node or extension node
key = encoding.terminator(encoding.hp_to_hex(node[0]), False)
if _node_type == "Leaf":
#print("prefix:", prefix, "key:", key)
if len(prefix) < len(key) and prefix == key[:len(prefix)]:
return node, curr_prefix
else:
return "", curr_prefix
if _node_type == "Extension":
print("extendsion node:", node, "key:", key, "prefix:", prefix)
if len(prefix) < len(key) and prefix == key[:len(prefix)]:
return node, curr_prefix
elif prefix not in key and len(prefix) < len(key):
return "", curr_prefix
elif len(prefix) > len(key) and prefix[:len(key)] != key:
return "", curr_prefix
else:
curr_prefix += key
node, curr_prefix = self.search_prefix(self.decode(node[1]),
prefix[len(key):],
curr_prefix)
return node, curr_prefix
def update_node(self, node, key, value):
_node_type = self.node_type(node)
#print("Node Type:", _node_type)
if _node_type == 'Branch':
#key空，直接將value 存在branch node 的最後
if not key:
node[-1] = value
#沿著branch node繼續往下找
else:
new_node = self.update_and_delete(self.decode(node[key[0]]), key[1:], value)
node[key[0]] = self.update_db(new_node)
return node
elif _node_type == 'Leaf' or _node_type == 'Extension':
original_key = ori_key = encoding.terminator(encoding.hp_to_hex(node[0]),False)
prefix = 0
for i in range(min(len(ori_key), len(key))):
if key[i] != ori_key[i]:
break
prefix = i + 1
key = key[prefix:]
ori_key = ori_key[prefix:]
#與現在node's key一樣
if key == ori_key == []:
if _node_type == 'Leaf':
return [node[0], value]
new_node = self.update_and_delete(self.decode(node[1]), key, value)
elif ori_key == []:
#查此extension node的child
if _node_type == 'Extension':
new_node = self.update_and_delete(self.decode(node[1]), key, value)
#如果是leaf node 開一個branch node 將原本node和new node放進新的branch
else:
new_node = [""]*17
new_node[-1] = node[1]
new_node[key[0]] = self.update_db([encoding.hex_to_hp(encoding.terminator(key[1:],True)), value])
else:
new_node = [""]*17
if len(ori_key) == 1 and _node_type == "Extension":
new_node[ori_key[0]] = node[1]
else:
if _node_type == "Extension":
ter = False
else:
ter = True
new_node[ori_key[0]] = self.update_db([encoding.hex_to_hp(encoding.terminator(ori_key[1:],ter)),node[1]])
#if key空 value直接放進branch，else 把剩下的key value存入branch
if key == []:
new_node[-1] = value
else:
new_node[key[0]] = self.update_db([encoding.hex_to_hp(encoding.terminator(key[1:],True)), value])
#change current node to a extension node which connected with the branch node we create above
if prefix > 0:
new_node = [encoding.hex_to_hp(original_key[:prefix]), self.update_db(new_node)]
return new_node
elif _node_type == "Blank":
return [encoding.hex_to_hp(encoding.terminator(key,True)), value]
def delete_node(self, node, key):
_node_type = self.node_type(node)
if _node_type == "Blank":
return ""
elif _node_type == "Branch":
#key empty, find it
if not key:
node[-1] = ""
#print("Node after delete",node)
else:
new_node = self.delete_and_delete(self.decode(node[key[0]]), key[1:])
new_node = self.update_db(new_node)
if new_node == node[key[0]]:
return node
else:
node[key[0]] = new_node
#after deleting, if the branch node has only one child, change it into extension/leaf node
count = 0
not_blank = []
for idx in range(17):
if node[idx] != "":
count += 1
not_blank.append(idx)
if count > 1:
return node
else:
#return leaf node
if not_blank[0] == END:
return [encoding.hex_to_hp(encoding.terminator([], True)), node[-1]]
else:
child_node = self.decode(node[not_blank[0]])
child_node_type = self.node_type(child_node)
if child_node_type == "Branch":
return [encoding.hex_to_hp(not_blank), self.update_db(child_node)]
elif child_node_type == "Leaf" or child_node_type == "Extension":
new_key = not_blank + encoding.hp_to_hex(child_node[0])
return [encoding.hex_to_hp(new_key), child_node[1]]
else:
original_key = encoding.terminator(encoding.hp_to_hex(node[0]),False)
if _node_type == "Leaf":
if original_key == key:
return ""
else:
return node
if len(original_key) > len(key) or key[:len(original_key)] != original_key:
return node
new_node = self.delete_and_delete(self.decode(node[1]), key[len(original_key):])
#child is not found
if new_node == self.decode(node[1]):
return node
if new_node == "":
return ""
#some nodes have been changed
else:
new_node_type = self.node_type(new_node)
if new_node_type == "Branch":
return [encoding.hex_to_hp(original_key), self.update_db(new_node)]
else:
original_key = original_key + encoding.hp_to_hex(new_node[0])
return [encoding.hex_to_hp(original_key), new_node[1]]