synapse-product/synapse/push/push_rule_evaluator.py
Patrick Cloke b44fbdffa4
Move free functions into PushRuleEvaluatorForEvent. ()
* Move `_condition_checker` into `PushRuleEvaluatorForEvent`.
* Move the condition cache into `PushRuleEvaluatorForEvent`.
* Improve docstrings.
* Inline a method which is only called once.
2022-05-10 07:54:30 -04:00

303 lines
9.6 KiB
Python

# 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 Any, Dict, List, Mapping, Optional, Pattern, Tuple, Union
from matrix_common.regex import glob_to_regex, to_word_pattern
from synapse.events import EventBase
from synapse.types import UserID
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: EventBase, condition: Dict[str, Any], room_member_count: int
) -> bool:
return _test_ineq_condition(condition, room_member_count)
def _sender_notification_permission(
ev: EventBase,
condition: Dict[str, Any],
sender_power_level: int,
power_levels: Dict[str, Union[int, Dict[str, int]]],
) -> bool:
notif_level_key = condition.get("key")
if notif_level_key is None:
return False
notif_levels = power_levels.get("notifications", {})
assert isinstance(notif_levels, dict)
room_notif_level = notif_levels.get(notif_level_key, 50)
return sender_power_level >= room_notif_level
def _test_ineq_condition(condition: Dict[str, Any], number: int) -> bool:
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: List[Union[str, Dict]]) -> Dict[str, Any]:
"""
Converts a list of actions into a `tweaks` dict (which can then be passed to
the push gateway).
This function ignores all actions other than `set_tweak` actions, and treats
absent `value`s as `True`, which agrees with the only spec-defined treatment
of absent `value`s (namely, for `highlight` tweaks).
Args:
actions: list of actions
e.g. [
{"set_tweak": "a", "value": "AAA"},
{"set_tweak": "b", "value": "BBB"},
{"set_tweak": "highlight"},
"notify"
]
Returns:
dictionary of tweaks for those actions
e.g. {"a": "AAA", "b": "BBB", "highlight": True}
"""
tweaks = {}
for a in actions:
if not isinstance(a, dict):
continue
if "set_tweak" in a:
# value is allowed to be absent in which case the value assumed
# should be True.
tweaks[a["set_tweak"]] = a.get("value", True)
return tweaks
class PushRuleEvaluatorForEvent:
def __init__(
self,
event: EventBase,
room_member_count: int,
sender_power_level: int,
power_levels: Dict[str, Union[int, Dict[str, int]]],
):
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)
# Maps cache keys to final values.
self._condition_cache: Dict[str, bool] = {}
def check_conditions(
self, conditions: List[dict], uid: str, display_name: Optional[str]
) -> bool:
"""
Returns true if a user's conditions/user ID/display name match the event.
Args:
conditions: The user's conditions to match.
uid: The user's MXID.
display_name: The display name.
Returns:
True if all conditions match the event, False otherwise.
"""
for cond in conditions:
_cache_key = cond.get("_cache_key", None)
if _cache_key:
res = self._condition_cache.get(_cache_key, None)
if res is False:
return False
elif res is True:
continue
res = self.matches(cond, uid, display_name)
if _cache_key:
self._condition_cache[_cache_key] = bool(res)
if not res:
return False
return True
def matches(
self, condition: Dict[str, Any], user_id: str, display_name: Optional[str]
) -> bool:
"""
Returns true if a user's condition/user ID/display name match the event.
Args:
condition: The user's condition to match.
uid: The user's MXID.
display_name: The display name, or None if there is not one.
Returns:
True if the condition matches the event, False otherwise.
"""
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:
"""
Check an "event_match" push rule condition.
Args:
condition: The "event_match" push rule condition to match.
user_id: The user's MXID.
Returns:
True if the condition matches the event, False otherwise.
"""
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._value_cache.get(condition["key"], None)
if haystack is None:
return False
return _glob_matches(pattern, haystack)
def _contains_display_name(self, display_name: Optional[str]) -> bool:
"""
Check an "event_match" push rule condition.
Args:
display_name: The display name, or None if there is not one.
Returns:
True if the display name is found in the event body, False otherwise.
"""
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:
r1 = re.escape(display_name)
r1 = to_word_pattern(r1)
r = re.compile(r1, flags=re.IGNORECASE)
regex_cache[(display_name, False, True)] = r
return bool(r.search(body))
# Caches (string, is_glob, word_boundary) -> regex for push. See _glob_matches
regex_cache: LruCache[Tuple[str, bool, bool], Pattern] = LruCache(
50000, "regex_push_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_regex(glob, word_boundary=word_boundary)
regex_cache[(glob, True, word_boundary)] = r
return bool(r.search(value))
except re.error:
logger.warning("Failed to parse glob to regex: %r", glob)
return False
def _flatten_dict(
d: Union[EventBase, Mapping[str, Any]],
prefix: Optional[List[str]] = None,
result: Optional[Dict[str, str]] = None,
) -> Dict[str, str]:
if prefix is None:
prefix = []
if result is None:
result = {}
for key, value in d.items():
if isinstance(value, str):
result[".".join(prefix + [key])] = value.lower()
elif isinstance(value, Mapping):
_flatten_dict(value, prefix=(prefix + [key]), result=result)
return result