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]]