mirror of
https://github.com/PiBrewing/craftbeerpi4.git
synced 2024-12-24 06:24:55 +01:00
79 lines
2.7 KiB
Python
79 lines
2.7 KiB
Python
|
class MQTTMatcher(object):
|
||
|
|
"""Intended to manage topic filters including wildcards.
|
||
|
|
|
||
|
|
Internally, MQTTMatcher use a prefix tree (trie) to store
|
||
|
|
values associated with filters, and has an iter_match()
|
||
|
|
method to iterate efficiently over all filters that match
|
||
|
|
some topic name."""
|
||
|
|
|
||
|
|
class Node(object):
|
||
|
|
__slots__ = '_children', '_content'
|
||
|
|
|
||
|
|
def __init__(self):
|
||
|
|
self._children = {}
|
||
|
|
self._content = None
|
||
|
|
|
||
|
|
def __init__(self):
|
||
|
|
self._root = self.Node()
|
||
|
|
|
||
|
|
def __setitem__(self, key, value):
|
||
|
|
"""Add a topic filter :key to the prefix tree
|
||
|
|
and associate it to :value"""
|
||
|
|
node = self._root
|
||
|
|
for sym in key.split('/'):
|
||
|
|
node = node._children.setdefault(sym, self.Node())
|
||
|
|
node._content = value
|
||
|
|
|
||
|
|
def __getitem__(self, key):
|
||
|
|
"""Retrieve the value associated with some topic filter :key"""
|
||
|
|
try:
|
||
|
|
node = self._root
|
||
|
|
for sym in key.split('/'):
|
||
|
|
node = node._children[sym]
|
||
|
|
if node._content is None:
|
||
|
|
raise KeyError(key)
|
||
|
|
return node._content
|
||
|
|
except KeyError:
|
||
|
|
raise KeyError(key)
|
||
|
|
|
||
|
|
def __delitem__(self, key):
|
||
|
|
"""Delete the value associated with some topic filter :key"""
|
||
|
|
lst = []
|
||
|
|
try:
|
||
|
|
parent, node = None, self._root
|
||
|
|
for k in key.split('/'):
|
||
|
|
parent, node = node, node._children[k]
|
||
|
|
lst.append((parent, k, node))
|
||
|
|
# TODO
|
||
|
|
node._content = None
|
||
|
|
except KeyError:
|
||
|
|
raise KeyError(key)
|
||
|
|
else: # cleanup
|
||
|
|
for parent, k, node in reversed(lst):
|
||
|
|
if node._children or node._content is not None:
|
||
|
|
break
|
||
|
|
del parent._children[k]
|
||
|
|
|
||
|
|
def iter_match(self, topic):
|
||
|
|
"""Return an iterator on all values associated with filters
|
||
|
|
that match the :topic"""
|
||
|
|
lst = topic.split('/')
|
||
|
|
normal = not topic.startswith('$')
|
||
|
|
def rec(node, i=0):
|
||
|
|
if i == len(lst):
|
||
|
|
if node._content is not None:
|
||
|
|
yield node._content
|
||
|
|
else:
|
||
|
|
part = lst[i]
|
||
|
|
if part in node._children:
|
||
|
|
for content in rec(node._children[part], i + 1):
|
||
|
|
yield content
|
||
|
|
if '+' in node._children and (normal or i > 0):
|
||
|
|
for content in rec(node._children['+'], i + 1):
|
||
|
|
yield content
|
||
|
|
if '#' in node._children and (normal or i > 0):
|
||
|
|
content = node._children['#']._content
|
||
|
|
if content is not None:
|
||
|
|
yield content
|
||
|
|
return rec(self._root)
|