forked-synapse/synapse/push/push_rule_evaluator.py

251 lines
7.8 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2015, 2016 OpenMarket Ltd
# Copyright 2017 New Vector Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
import re
from typing import Pattern
from synapse.events import EventBase
from synapse.types import UserID
from synapse.util.caches import register_cache
from synapse.util.caches.lrucache import LruCache
logger = logging.getLogger(__name__)
GLOB_REGEX = re.compile(r"\\\[(\\\!|)(.*)\\\]")
IS_GLOB = re.compile(r"[\?\*\[\]]")
INEQUALITY_EXPR = re.compile("^([=<>]*)([0-9]*)$")
def _room_member_count(ev, condition, room_member_count):
return _test_ineq_condition(condition, room_member_count)
def _sender_notification_permission(ev, condition, sender_power_level, power_levels):
notif_level_key = condition.get("key")
if notif_level_key is None:
return False
notif_levels = power_levels.get("notifications", {})
room_notif_level = notif_levels.get(notif_level_key, 50)
return sender_power_level >= room_notif_level
def _test_ineq_condition(condition, number):
if "is" not in condition:
return False
m = INEQUALITY_EXPR.match(condition["is"])
if not m:
return False
ineq = m.group(1)
rhs = m.group(2)
if not rhs.isdigit():
return False
rhs_int = int(rhs)
if ineq == "" or ineq == "==":
return number == rhs_int
elif ineq == "<":
return number < rhs_int
elif ineq == ">":
return number > rhs_int
elif ineq == ">=":
return number >= rhs_int
elif ineq == "<=":
return number <= rhs_int
else:
return False
def tweaks_for_actions(actions):
tweaks = {}
for a in actions:
if not isinstance(a, dict):
continue
if "set_tweak" in a and "value" in a:
tweaks[a["set_tweak"]] = a["value"]
return tweaks
class PushRuleEvaluatorForEvent(object):
def __init__(
self,
event: EventBase,
room_member_count: int,
sender_power_level: int,
power_levels: dict,
):
self._event = event
self._room_member_count = room_member_count
self._sender_power_level = sender_power_level
self._power_levels = power_levels
# Maps strings of e.g. 'content.body' -> event["content"]["body"]
self._value_cache = _flatten_dict(event)
def matches(self, condition: dict, user_id: str, display_name: str) -> bool:
if condition["kind"] == "event_match":
return self._event_match(condition, user_id)
elif condition["kind"] == "contains_display_name":
return self._contains_display_name(display_name)
elif condition["kind"] == "room_member_count":
return _room_member_count(self._event, condition, self._room_member_count)
elif condition["kind"] == "sender_notification_permission":
return _sender_notification_permission(
self._event, condition, self._sender_power_level, self._power_levels
)
else:
return True
def _event_match(self, condition: dict, user_id: str) -> bool:
pattern = condition.get("pattern", None)
if not pattern:
pattern_type = condition.get("pattern_type", None)
if pattern_type == "user_id":
pattern = user_id
elif pattern_type == "user_localpart":
pattern = UserID.from_string(user_id).localpart
if not pattern:
logger.warning("event_match condition with no pattern")
return False
# XXX: optimisation: cache our pattern regexps
if condition["key"] == "content.body":
body = self._event.content.get("body", None)
if not body or not isinstance(body, str):
return False
return _glob_matches(pattern, body, word_boundary=True)
else:
haystack = self._get_value(condition["key"])
if haystack is None:
return False
return _glob_matches(pattern, haystack)
def _contains_display_name(self, display_name: str) -> bool:
if not display_name:
return False
body = self._event.content.get("body", None)
if not body or not isinstance(body, str):
return False
# Similar to _glob_matches, but do not treat display_name as a glob.
r = regex_cache.get((display_name, False, True), None)
if not r:
r = re.escape(display_name)
r = _re_word_boundary(r)
r = re.compile(r, flags=re.IGNORECASE)
regex_cache[(display_name, False, True)] = r
return r.search(body)
def _get_value(self, dotted_key: str) -> str:
return self._value_cache.get(dotted_key, None)
# Caches (string, is_glob, word_boundary) -> regex for push. See _glob_matches
regex_cache = LruCache(50000)
register_cache("cache", "regex_push_cache", regex_cache)
def _glob_matches(glob: str, value: str, word_boundary: bool = False) -> bool:
"""Tests if value matches glob.
Args:
glob
value: String to test against glob.
word_boundary: Whether to match against word boundaries or entire
string. Defaults to False.
"""
try:
r = regex_cache.get((glob, True, word_boundary), None)
if not r:
r = _glob_to_re(glob, word_boundary)
regex_cache[(glob, True, word_boundary)] = r
return r.search(value)
except re.error:
logger.warning("Failed to parse glob to regex: %r", glob)
return False
def _glob_to_re(glob: str, word_boundary: bool) -> Pattern:
"""Generates regex for a given glob.
Args:
glob
word_boundary: Whether to match against word boundaries or entire string.
"""
if IS_GLOB.search(glob):
r = re.escape(glob)
r = r.replace(r"\*", ".*?")
r = r.replace(r"\?", ".")
# handle [abc], [a-z] and [!a-z] style ranges.
r = GLOB_REGEX.sub(
lambda x: (
"[%s%s]" % (x.group(1) and "^" or "", x.group(2).replace(r"\\\-", "-"))
),
r,
)
if word_boundary:
r = _re_word_boundary(r)
return re.compile(r, flags=re.IGNORECASE)
else:
r = "^" + r + "$"
return re.compile(r, flags=re.IGNORECASE)
elif word_boundary:
r = re.escape(glob)
r = _re_word_boundary(r)
return re.compile(r, flags=re.IGNORECASE)
else:
r = "^" + re.escape(glob) + "$"
return re.compile(r, flags=re.IGNORECASE)
def _re_word_boundary(r: str) -> str:
"""
Adds word boundary characters to the start and end of an
expression to require that the match occur as a whole word,
but do so respecting the fact that strings starting or ending
with non-word characters will change word boundaries.
"""
# we can't use \b as it chokes on unicode. however \W seems to be okay
# as shorthand for [^0-9A-Za-z_].
return r"(^|\W)%s(\W|$)" % (r,)
def _flatten_dict(d, prefix=[], result=None):
if result is None:
result = {}
for key, value in d.items():
if isinstance(value, str):
result[".".join(prefix + [key])] = value.lower()
elif hasattr(value, "items"):
_flatten_dict(value, prefix=(prefix + [key]), result=result)
return result