zulip/zerver/lib/narrow.py

1267 lines
48 KiB
Python

import os
import re
from dataclasses import dataclass
from typing import (
Any,
Callable,
Collection,
Dict,
Generic,
Iterable,
List,
Mapping,
Optional,
Sequence,
Tuple,
TypeVar,
Union,
)
import orjson
from django.conf import settings
from django.core.exceptions import ValidationError
from django.db import connection
from django.utils.translation import gettext as _
from sqlalchemy.dialects import postgresql
from sqlalchemy.engine import Connection, Row
from sqlalchemy.sql import (
ClauseElement,
ColumnElement,
Select,
and_,
column,
func,
join,
literal,
literal_column,
not_,
or_,
select,
table,
union_all,
)
from sqlalchemy.sql.selectable import SelectBase
from sqlalchemy.types import ARRAY, Boolean, Integer, Text
from zerver.lib.addressee import get_user_profiles, get_user_profiles_by_ids
from zerver.lib.exceptions import ErrorCode, JsonableError
from zerver.lib.message import get_first_visible_message_id
from zerver.lib.recipient_users import recipient_for_user_profiles
from zerver.lib.sqlalchemy_utils import get_sqlalchemy_connection
from zerver.lib.streams import (
can_access_stream_history_by_id,
can_access_stream_history_by_name,
get_public_streams_queryset,
get_stream_by_narrow_operand_access_unchecked,
get_web_public_streams_queryset,
)
from zerver.lib.topic import (
RESOLVED_TOPIC_PREFIX,
get_resolved_topic_condition_sa,
get_topic_from_message_info,
topic_column_sa,
topic_match_sa,
)
from zerver.lib.types import Validator
from zerver.lib.user_topics import exclude_topic_mutes
from zerver.lib.validator import (
check_bool,
check_dict,
check_required_string,
check_string,
check_string_or_int,
check_string_or_int_list,
)
from zerver.models import (
Realm,
Recipient,
Stream,
Subscription,
UserMessage,
UserProfile,
get_active_streams,
get_user_by_id_in_realm_including_cross_realm,
get_user_including_cross_realm,
)
stop_words_list: Optional[List[str]] = None
def read_stop_words() -> List[str]:
global stop_words_list
if stop_words_list is None:
file_path = os.path.join(
settings.DEPLOY_ROOT, "puppet/zulip/files/postgresql/zulip_english.stop"
)
with open(file_path) as f:
stop_words_list = f.read().splitlines()
return stop_words_list
def check_supported_events_narrow_filter(narrow: Iterable[Sequence[str]]) -> None:
for element in narrow:
operator = element[0]
if operator not in ["stream", "topic", "sender", "is"]:
raise JsonableError(_("Operator {} not supported.").format(operator))
def is_spectator_compatible(narrow: Iterable[Dict[str, Any]]) -> bool:
# This implementation should agree with the similar function in static/js/hash_util.js.
for element in narrow:
operator = element["operator"]
if "operand" not in element:
return False
if operator not in ["streams", "stream", "topic", "sender", "has", "search", "near", "id"]:
return False
return True
def is_web_public_narrow(narrow: Optional[Iterable[Dict[str, Any]]]) -> bool:
if narrow is None:
return False
return any(
# Web-public queries are only allowed for limited types of narrows.
# term == {'operator': 'streams', 'operand': 'web-public', 'negated': False}
term["operator"] == "streams"
and term["operand"] == "web-public"
and term["negated"] is False
for term in narrow
)
def build_narrow_filter(narrow: Collection[Sequence[str]]) -> Callable[[Mapping[str, Any]], bool]:
"""Changes to this function should come with corresponding changes to
BuildNarrowFilterTest."""
check_supported_events_narrow_filter(narrow)
def narrow_filter(event: Mapping[str, Any]) -> bool:
message = event["message"]
flags = event["flags"]
for element in narrow:
operator = element[0]
operand = element[1]
if operator == "stream":
if message["type"] != "stream":
return False
if operand.lower() != message["display_recipient"].lower():
return False
elif operator == "topic":
if message["type"] != "stream":
return False
topic_name = get_topic_from_message_info(message)
if operand.lower() != topic_name.lower():
return False
elif operator == "sender":
if operand.lower() != message["sender_email"].lower():
return False
elif operator == "is" and operand == "private":
if message["type"] != "private":
return False
elif operator == "is" and operand in ["starred"]:
if operand not in flags:
return False
elif operator == "is" and operand == "unread":
if "read" in flags:
return False
elif operator == "is" and operand in ["alerted", "mentioned"]:
if "mentioned" not in flags:
return False
elif operator == "is" and operand == "resolved":
if message["type"] != "stream":
return False
topic_name = get_topic_from_message_info(message)
if not topic_name.startswith(RESOLVED_TOPIC_PREFIX):
return False
return True
return narrow_filter
LARGER_THAN_MAX_MESSAGE_ID = 10000000000000000
class BadNarrowOperatorError(JsonableError):
code = ErrorCode.BAD_NARROW
data_fields = ["desc"]
def __init__(self, desc: str) -> None:
self.desc: str = desc
@staticmethod
def msg_format() -> str:
return _("Invalid narrow operator: {desc}")
ConditionTransform = Callable[[ClauseElement], ClauseElement]
OptionalNarrowListT = Optional[List[Dict[str, Any]]]
# These delimiters will not appear in rendered messages or HTML-escaped topics.
TS_START = "<ts-match>"
TS_STOP = "</ts-match>"
def ts_locs_array(
config: ColumnElement[Text],
text: ColumnElement[Text],
tsquery: ColumnElement[Any],
) -> ColumnElement[ARRAY[Integer]]:
options = f"HighlightAll = TRUE, StartSel = {TS_START}, StopSel = {TS_STOP}"
delimited = func.ts_headline(config, text, tsquery, options, type_=Text)
part = func.unnest(
func.string_to_array(delimited, TS_START, type_=ARRAY(Text)), type_=Text
).column_valued()
part_len = func.length(part, type_=Integer) - len(TS_STOP)
match_pos = func.sum(part_len, type_=Integer).over(rows=(None, -1)) + len(TS_STOP)
match_len = func.strpos(part, TS_STOP, type_=Integer) - 1
return func.array(
select(postgresql.array([match_pos, match_len])).offset(1).scalar_subquery(),
type_=ARRAY(Integer),
)
class NarrowBuilder:
"""
Build up a SQLAlchemy query to find messages matching a narrow.
"""
# This class has an important security invariant:
#
# None of these methods ever *add* messages to a query's result.
#
# That is, the `add_term` method, and its helpers the `by_*` methods,
# are passed a Select object representing a query for messages; they may
# call some methods on it, and then they return a resulting Select
# object. Things these methods may do to the queries they handle
# include
# * add conditions to filter out rows (i.e., messages), with `query.where`
# * add columns for more information on the same message, with `query.column`
# * add a join for more information on the same message
#
# Things they may not do include
# * anything that would pull in additional rows, or information on
# other messages.
def __init__(
self,
user_profile: Optional[UserProfile],
msg_id_column: ColumnElement[Integer],
realm: Realm,
is_web_public_query: bool = False,
) -> None:
self.user_profile = user_profile
self.msg_id_column = msg_id_column
self.realm = realm
self.is_web_public_query = is_web_public_query
def add_term(self, query: Select, term: Dict[str, Any]) -> Select:
"""
Extend the given query to one narrowed by the given term, and return the result.
This method satisfies an important security property: the returned
query never includes a message that the given query didn't. In
particular, if the given query will only find messages that a given
user can legitimately see, then so will the returned query.
"""
# To maintain the security property, we hold all the `by_*`
# methods to the same criterion. See the class's block comment
# for details.
# We have to be careful here because we're letting users call a method
# by name! The prefix 'by_' prevents it from colliding with builtin
# Python __magic__ stuff.
operator = term["operator"]
operand = term["operand"]
negated = term.get("negated", False)
method_name = "by_" + operator.replace("-", "_")
method = getattr(self, method_name, None)
if method is None:
raise BadNarrowOperatorError("unknown operator " + operator)
if negated:
maybe_negate = not_
else:
maybe_negate = lambda cond: cond
return method(query, operand, maybe_negate)
def by_has(self, query: Select, operand: str, maybe_negate: ConditionTransform) -> Select:
if operand not in ["attachment", "image", "link"]:
raise BadNarrowOperatorError("unknown 'has' operand " + operand)
col_name = "has_" + operand
cond = column(col_name, Boolean)
return query.where(maybe_negate(cond))
def by_in(self, query: Select, operand: str, maybe_negate: ConditionTransform) -> Select:
# This operator does not support is_web_public_query.
assert not self.is_web_public_query
assert self.user_profile is not None
if operand == "home":
conditions = exclude_muting_conditions(self.user_profile, [])
return query.where(and_(*conditions))
elif operand == "all":
return query
raise BadNarrowOperatorError("unknown 'in' operand " + operand)
def by_is(self, query: Select, operand: str, maybe_negate: ConditionTransform) -> Select:
# This operator class does not support is_web_public_query.
assert not self.is_web_public_query
assert self.user_profile is not None
if operand == "private":
cond = column("flags", Integer).op("&")(UserMessage.flags.is_private.mask) != 0
return query.where(maybe_negate(cond))
elif operand == "starred":
cond = column("flags", Integer).op("&")(UserMessage.flags.starred.mask) != 0
return query.where(maybe_negate(cond))
elif operand == "unread":
cond = column("flags", Integer).op("&")(UserMessage.flags.read.mask) == 0
return query.where(maybe_negate(cond))
elif operand == "mentioned":
cond1 = column("flags", Integer).op("&")(UserMessage.flags.mentioned.mask) != 0
cond2 = column("flags", Integer).op("&")(UserMessage.flags.wildcard_mentioned.mask) != 0
cond = or_(cond1, cond2)
return query.where(maybe_negate(cond))
elif operand == "alerted":
cond = column("flags", Integer).op("&")(UserMessage.flags.has_alert_word.mask) != 0
return query.where(maybe_negate(cond))
elif operand == "resolved":
cond = get_resolved_topic_condition_sa()
return query.where(maybe_negate(cond))
raise BadNarrowOperatorError("unknown 'is' operand " + operand)
_alphanum = frozenset("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
def _pg_re_escape(self, pattern: str) -> str:
"""
Escape user input to place in a regex
Python's re.escape escapes Unicode characters in a way which PostgreSQL
fails on, '\u03bb' to '\\\u03bb'. This function will correctly escape
them for PostgreSQL, '\u03bb' to '\\u03bb'.
"""
s = list(pattern)
for i, c in enumerate(s):
if c not in self._alphanum:
if ord(c) >= 128:
# convert the character to hex PostgreSQL regex will take
# \uXXXX
s[i] = f"\\u{ord(c):0>4x}"
else:
s[i] = "\\" + c
return "".join(s)
def by_stream(
self, query: Select, operand: Union[str, int], maybe_negate: ConditionTransform
) -> Select:
try:
# Because you can see your own message history for
# private streams you are no longer subscribed to, we
# need get_stream_by_narrow_operand_access_unchecked here.
stream = get_stream_by_narrow_operand_access_unchecked(operand, self.realm)
if self.is_web_public_query and not stream.is_web_public:
raise BadNarrowOperatorError("unknown web-public stream " + str(operand))
except Stream.DoesNotExist:
raise BadNarrowOperatorError("unknown stream " + str(operand))
if self.realm.is_zephyr_mirror_realm:
# MIT users expect narrowing to "social" to also show messages to
# /^(un)*social(.d)*$/ (unsocial, ununsocial, social.d, ...).
# In `ok_to_include_history`, we assume that a non-negated
# `stream` term for a public stream will limit the query to
# that specific stream. So it would be a bug to hit this
# codepath after relying on this term there. But all streams in
# a Zephyr realm are private, so that doesn't happen.
assert not stream.is_public()
m = re.search(r"^(?:un)*(.+?)(?:\.d)*$", stream.name, re.IGNORECASE)
# Since the regex has a `.+` in it and "" is invalid as a
# stream name, this will always match
assert m is not None
base_stream_name = m.group(1)
matching_streams = get_active_streams(self.realm).filter(
name__iregex=rf"^(un)*{self._pg_re_escape(base_stream_name)}(\.d)*$"
)
recipient_ids = [matching_stream.recipient_id for matching_stream in matching_streams]
cond = column("recipient_id", Integer).in_(recipient_ids)
return query.where(maybe_negate(cond))
recipient = stream.recipient
assert recipient is not None
cond = column("recipient_id", Integer) == recipient.id
return query.where(maybe_negate(cond))
def by_streams(self, query: Select, operand: str, maybe_negate: ConditionTransform) -> Select:
if operand == "public":
# Get all both subscribed and non-subscribed public streams
# but exclude any private subscribed streams.
recipient_queryset = get_public_streams_queryset(self.realm)
elif operand == "web-public":
recipient_queryset = get_web_public_streams_queryset(self.realm)
else:
raise BadNarrowOperatorError("unknown streams operand " + operand)
recipient_ids = recipient_queryset.values_list("recipient_id", flat=True).order_by("id")
cond = column("recipient_id", Integer).in_(recipient_ids)
return query.where(maybe_negate(cond))
def by_topic(self, query: Select, operand: str, maybe_negate: ConditionTransform) -> Select:
if self.realm.is_zephyr_mirror_realm:
# MIT users expect narrowing to topic "foo" to also show messages to /^foo(.d)*$/
# (foo, foo.d, foo.d.d, etc)
m = re.search(r"^(.*?)(?:\.d)*$", operand, re.IGNORECASE)
# Since the regex has a `.*` in it, this will always match
assert m is not None
base_topic = m.group(1)
# Additionally, MIT users expect the empty instance and
# instance "personal" to be the same.
if base_topic in ("", "personal", '(instance "")'):
cond: ClauseElement = or_(
topic_match_sa(""),
topic_match_sa(".d"),
topic_match_sa(".d.d"),
topic_match_sa(".d.d.d"),
topic_match_sa(".d.d.d.d"),
topic_match_sa("personal"),
topic_match_sa("personal.d"),
topic_match_sa("personal.d.d"),
topic_match_sa("personal.d.d.d"),
topic_match_sa("personal.d.d.d.d"),
topic_match_sa('(instance "")'),
topic_match_sa('(instance "").d'),
topic_match_sa('(instance "").d.d'),
topic_match_sa('(instance "").d.d.d'),
topic_match_sa('(instance "").d.d.d.d'),
)
else:
# We limit `.d` counts, since PostgreSQL has much better
# query planning for this than they do for a regular
# expression (which would sometimes table scan).
cond = or_(
topic_match_sa(base_topic),
topic_match_sa(base_topic + ".d"),
topic_match_sa(base_topic + ".d.d"),
topic_match_sa(base_topic + ".d.d.d"),
topic_match_sa(base_topic + ".d.d.d.d"),
)
return query.where(maybe_negate(cond))
cond = topic_match_sa(operand)
return query.where(maybe_negate(cond))
def by_sender(
self, query: Select, operand: Union[str, int], maybe_negate: ConditionTransform
) -> Select:
try:
if isinstance(operand, str):
sender = get_user_including_cross_realm(operand, self.realm)
else:
sender = get_user_by_id_in_realm_including_cross_realm(operand, self.realm)
except UserProfile.DoesNotExist:
raise BadNarrowOperatorError("unknown user " + str(operand))
cond = column("sender_id", Integer) == literal(sender.id)
return query.where(maybe_negate(cond))
def by_near(self, query: Select, operand: str, maybe_negate: ConditionTransform) -> Select:
return query
def by_id(
self, query: Select, operand: Union[int, str], maybe_negate: ConditionTransform
) -> Select:
if not str(operand).isdigit():
raise BadNarrowOperatorError("Invalid message ID")
cond = self.msg_id_column == literal(operand)
return query.where(maybe_negate(cond))
def by_pm_with(
self, query: Select, operand: Union[str, Iterable[int]], maybe_negate: ConditionTransform
) -> Select:
# This operator does not support is_web_public_query.
assert not self.is_web_public_query
assert self.user_profile is not None
try:
if isinstance(operand, str):
email_list = operand.split(",")
user_profiles = get_user_profiles(
emails=email_list,
realm=self.realm,
)
else:
"""
This is where we handle passing a list of user IDs for the narrow, which is the
preferred/cleaner API.
"""
user_profiles = get_user_profiles_by_ids(
user_ids=operand,
realm=self.realm,
)
recipient = recipient_for_user_profiles(
user_profiles=user_profiles,
forwarded_mirror_message=False,
forwarder_user_profile=None,
sender=self.user_profile,
allow_deactivated=True,
)
except (JsonableError, ValidationError):
raise BadNarrowOperatorError("unknown user in " + str(operand))
# Group DM
if recipient.type == Recipient.HUDDLE:
cond = column("recipient_id", Integer) == recipient.id
return query.where(maybe_negate(cond))
# 1:1 PM
other_participant = None
# Find if another person is in PM
for user in user_profiles:
if user.id != self.user_profile.id:
other_participant = user
# PM with another person
if other_participant:
# We need bidirectional messages PM with another person.
# But Recipient.PERSONAL objects only encode the person who
# received the message, and not the other participant in
# the thread (the sender), we need to do a somewhat
# complex query to get messages between these two users
# with either of them as the sender.
self_recipient_id = self.user_profile.recipient_id
cond = or_(
and_(
column("sender_id", Integer) == other_participant.id,
column("recipient_id", Integer) == self_recipient_id,
),
and_(
column("sender_id", Integer) == self.user_profile.id,
column("recipient_id", Integer) == recipient.id,
),
)
return query.where(maybe_negate(cond))
# PM with self
cond = and_(
column("sender_id", Integer) == self.user_profile.id,
column("recipient_id", Integer) == recipient.id,
)
return query.where(maybe_negate(cond))
def by_group_pm_with(
self, query: Select, operand: Union[str, int], maybe_negate: ConditionTransform
) -> Select:
# This operator does not support is_web_public_query.
assert not self.is_web_public_query
assert self.user_profile is not None
try:
if isinstance(operand, str):
narrow_profile = get_user_including_cross_realm(operand, self.realm)
else:
narrow_profile = get_user_by_id_in_realm_including_cross_realm(operand, self.realm)
except UserProfile.DoesNotExist:
raise BadNarrowOperatorError("unknown user " + str(operand))
self_recipient_ids = [
recipient_tuple["recipient_id"]
for recipient_tuple in Subscription.objects.filter(
user_profile=self.user_profile,
recipient__type=Recipient.HUDDLE,
).values("recipient_id")
]
narrow_recipient_ids = [
recipient_tuple["recipient_id"]
for recipient_tuple in Subscription.objects.filter(
user_profile=narrow_profile,
recipient__type=Recipient.HUDDLE,
).values("recipient_id")
]
recipient_ids = set(self_recipient_ids) & set(narrow_recipient_ids)
cond = column("recipient_id", Integer).in_(recipient_ids)
return query.where(maybe_negate(cond))
def by_search(self, query: Select, operand: str, maybe_negate: ConditionTransform) -> Select:
if settings.USING_PGROONGA:
return self._by_search_pgroonga(query, operand, maybe_negate)
else:
return self._by_search_tsearch(query, operand, maybe_negate)
def _by_search_pgroonga(
self, query: Select, operand: str, maybe_negate: ConditionTransform
) -> Select:
match_positions_character = func.pgroonga_match_positions_character
query_extract_keywords = func.pgroonga_query_extract_keywords
operand_escaped = func.escape_html(operand, type_=Text)
keywords = query_extract_keywords(operand_escaped)
query = query.add_columns(
match_positions_character(column("rendered_content", Text), keywords).label(
"content_matches"
),
match_positions_character(
func.escape_html(topic_column_sa(), type_=Text), keywords
).label("topic_matches"),
)
condition = column("search_pgroonga", Text).op("&@~")(operand_escaped)
return query.where(maybe_negate(condition))
def _by_search_tsearch(
self, query: Select, operand: str, maybe_negate: ConditionTransform
) -> Select:
tsquery = func.plainto_tsquery(literal("zulip.english_us_search"), literal(operand))
query = query.add_columns(
ts_locs_array(
literal("zulip.english_us_search", Text), column("rendered_content", Text), tsquery
).label("content_matches"),
# We HTML-escape the topic in PostgreSQL to avoid doing a server round-trip
ts_locs_array(
literal("zulip.english_us_search", Text),
func.escape_html(topic_column_sa(), type_=Text),
tsquery,
).label("topic_matches"),
)
# Do quoted string matching. We really want phrase
# search here so we can ignore punctuation and do
# stemming, but there isn't a standard phrase search
# mechanism in PostgreSQL
for term in re.findall(r'"[^"]+"|\S+', operand):
if term[0] == '"' and term[-1] == '"':
term = term[1:-1]
term = "%" + connection.ops.prep_for_like_query(term) + "%"
cond: ClauseElement = or_(
column("content", Text).ilike(term), topic_column_sa().ilike(term)
)
query = query.where(maybe_negate(cond))
cond = column("search_tsvector", postgresql.TSVECTOR).op("@@")(tsquery)
return query.where(maybe_negate(cond))
def narrow_parameter(var_name: str, json: str) -> OptionalNarrowListT:
data = orjson.loads(json)
if not isinstance(data, list):
raise ValueError("argument is not a list")
if len(data) == 0:
# The "empty narrow" should be None, and not []
return None
def convert_term(elem: Union[Dict[str, Any], List[str]]) -> Dict[str, Any]:
# We have to support a legacy tuple format.
if isinstance(elem, list):
if len(elem) != 2 or any(not isinstance(x, str) for x in elem):
raise ValueError("element is not a string pair")
return dict(operator=elem[0], operand=elem[1])
if isinstance(elem, dict):
# Make sure to sync this list to frontend also when adding a new operator.
# that supports user IDs. Relevant code is located in static/js/message_fetch.js
# in handle_operators_supporting_id_based_api function where you will need to update
# operators_supporting_id, or operators_supporting_ids array.
operators_supporting_id = ["sender", "group-pm-with", "stream"]
operators_supporting_ids = ["pm-with"]
operators_non_empty_operand = {"search"}
operator = elem.get("operator", "")
if operator in operators_supporting_id:
operand_validator: Validator[object] = check_string_or_int
elif operator in operators_supporting_ids:
operand_validator = check_string_or_int_list
elif operator in operators_non_empty_operand:
operand_validator = check_required_string
else:
operand_validator = check_string
validator = check_dict(
required_keys=[
("operator", check_string),
("operand", operand_validator),
],
optional_keys=[
("negated", check_bool),
],
)
try:
validator("elem", elem)
except ValidationError as error:
raise JsonableError(error.message)
# whitelist the fields we care about for now
return dict(
operator=elem["operator"],
operand=elem["operand"],
negated=elem.get("negated", False),
)
raise ValueError("element is not a dictionary")
return list(map(convert_term, data))
def ok_to_include_history(
narrow: OptionalNarrowListT, user_profile: Optional[UserProfile], is_web_public_query: bool
) -> bool:
# There are occasions where we need to find Message rows that
# have no corresponding UserMessage row, because the user is
# reading a public stream that might include messages that
# were sent while the user was not subscribed, but which they are
# allowed to see. We have to be very careful about constructing
# queries in those situations, so this function should return True
# only if we are 100% sure that we're gonna add a clause to the
# query that narrows to a particular public stream on the user's realm.
# If we screw this up, then we can get into a nasty situation of
# polluting our narrow results with messages from other realms.
# For web-public queries, we are always returning history. The
# analogues of the below stream access checks for whether streams
# have is_web_public set and banning is operators in this code
# path are done directly in NarrowBuilder.
if is_web_public_query:
assert user_profile is None
return True
assert user_profile is not None
include_history = False
if narrow is not None:
for term in narrow:
if term["operator"] == "stream" and not term.get("negated", False):
operand: Union[str, int] = term["operand"]
if isinstance(operand, str):
include_history = can_access_stream_history_by_name(user_profile, operand)
else:
include_history = can_access_stream_history_by_id(user_profile, operand)
elif (
term["operator"] == "streams"
and term["operand"] == "public"
and not term.get("negated", False)
and user_profile.can_access_public_streams()
):
include_history = True
# Disable historical messages if the user is narrowing on anything
# that's a property on the UserMessage table. There cannot be
# historical messages in these cases anyway.
for term in narrow:
if term["operator"] == "is":
include_history = False
return include_history
def get_stream_from_narrow_access_unchecked(
narrow: OptionalNarrowListT, realm: Realm
) -> Optional[Stream]:
if narrow is not None:
for term in narrow:
if term["operator"] == "stream":
return get_stream_by_narrow_operand_access_unchecked(term["operand"], realm)
return None
def exclude_muting_conditions(
user_profile: UserProfile, narrow: OptionalNarrowListT
) -> List[ClauseElement]:
conditions: List[ClauseElement] = []
stream_id = None
try:
# Note: It is okay here to not check access to stream
# because we are only using the stream id to exclude data,
# not to include results.
stream = get_stream_from_narrow_access_unchecked(narrow, user_profile.realm)
if stream is not None:
stream_id = stream.id
except Stream.DoesNotExist:
pass
# Stream-level muting only applies when looking at views that
# include multiple streams, since we do want users to be able to
# browser messages within a muted stream.
if stream_id is None:
rows = Subscription.objects.filter(
user_profile=user_profile,
active=True,
is_muted=True,
recipient__type=Recipient.STREAM,
).values("recipient_id")
muted_recipient_ids = [row["recipient_id"] for row in rows]
if len(muted_recipient_ids) > 0:
# Only add the condition if we have muted streams to simplify/avoid warnings.
condition = not_(column("recipient_id", Integer).in_(muted_recipient_ids))
conditions.append(condition)
conditions = exclude_topic_mutes(conditions, user_profile, stream_id)
# Muted user logic for hiding messages is implemented entirely
# client-side. This is by design, as it allows UI to hint that
# muted messages exist where their absence might make conversation
# difficult to understand. As a result, we do not need to consider
# muted users in this server-side logic for returning messages to
# clients. (We could in theory exclude PMs from muted users, but
# they're likely to be sufficiently rare to not be worth extra
# logic/testing here).
return conditions
def get_base_query_for_search(
user_profile: Optional[UserProfile], need_message: bool, need_user_message: bool
) -> Tuple[Select, ColumnElement[Integer]]:
# Handle the simple case where user_message isn't involved first.
if not need_user_message:
assert need_message
query = select(column("id", Integer).label("message_id")).select_from(
table("zerver_message")
)
inner_msg_id_col = literal_column("zerver_message.id", Integer)
return (query, inner_msg_id_col)
assert user_profile is not None
if need_message:
query = (
select(column("message_id", Integer), column("flags", Integer))
.where(column("user_profile_id", Integer) == literal(user_profile.id))
.select_from(
join(
table("zerver_usermessage"),
table("zerver_message"),
literal_column("zerver_usermessage.message_id", Integer)
== literal_column("zerver_message.id", Integer),
)
)
)
inner_msg_id_col = column("message_id", Integer)
return (query, inner_msg_id_col)
query = (
select(column("message_id", Integer), column("flags", Integer))
.where(column("user_profile_id", Integer) == literal(user_profile.id))
.select_from(table("zerver_usermessage"))
)
inner_msg_id_col = column("message_id", Integer)
return (query, inner_msg_id_col)
def add_narrow_conditions(
user_profile: Optional[UserProfile],
inner_msg_id_col: ColumnElement[Integer],
query: Select,
narrow: OptionalNarrowListT,
is_web_public_query: bool,
realm: Realm,
) -> Tuple[Select, bool]:
is_search = False # for now
if narrow is None:
return (query, is_search)
# Build the query for the narrow
builder = NarrowBuilder(user_profile, inner_msg_id_col, realm, is_web_public_query)
search_operands = []
# As we loop through terms, builder does most of the work to extend
# our query, but we need to collect the search operands and handle
# them after the loop.
for term in narrow:
if term["operator"] == "search":
search_operands.append(term["operand"])
else:
query = builder.add_term(query, term)
if search_operands:
is_search = True
query = query.add_columns(topic_column_sa(), column("rendered_content", Text))
search_term = dict(
operator="search",
operand=" ".join(search_operands),
)
query = builder.add_term(query, search_term)
return (query, is_search)
def find_first_unread_anchor(
sa_conn: Connection, user_profile: Optional[UserProfile], narrow: OptionalNarrowListT
) -> int:
# For anonymous web users, all messages are treated as read, and so
# always return LARGER_THAN_MAX_MESSAGE_ID.
if user_profile is None:
return LARGER_THAN_MAX_MESSAGE_ID
# We always need UserMessage in our query, because it has the unread
# flag for the user.
need_user_message = True
# Because we will need to call exclude_muting_conditions, unless
# the user hasn't muted anything, we will need to include Message
# in our query. It may be worth eventually adding an optimization
# for the case of a user who hasn't muted anything to avoid the
# join in that case, but it's low priority.
need_message = True
query, inner_msg_id_col = get_base_query_for_search(
user_profile=user_profile,
need_message=need_message,
need_user_message=need_user_message,
)
query, is_search = add_narrow_conditions(
user_profile=user_profile,
inner_msg_id_col=inner_msg_id_col,
query=query,
narrow=narrow,
is_web_public_query=False,
realm=user_profile.realm,
)
condition = column("flags", Integer).op("&")(UserMessage.flags.read.mask) == 0
# We exclude messages on muted topics when finding the first unread
# message in this narrow
muting_conditions = exclude_muting_conditions(user_profile, narrow)
if muting_conditions:
condition = and_(condition, *muting_conditions)
first_unread_query = query.where(condition)
first_unread_query = first_unread_query.order_by(inner_msg_id_col.asc()).limit(1)
first_unread_result = list(sa_conn.execute(first_unread_query).fetchall())
if len(first_unread_result) > 0:
anchor = first_unread_result[0][0]
else:
anchor = LARGER_THAN_MAX_MESSAGE_ID
return anchor
def parse_anchor_value(anchor_val: Optional[str], use_first_unread_anchor: bool) -> Optional[int]:
"""Given the anchor and use_first_unread_anchor parameters passed by
the client, computes what anchor value the client requested,
handling backwards-compatibility and the various string-valued
fields. We encode use_first_unread_anchor as anchor=None.
"""
if use_first_unread_anchor:
# Backwards-compatibility: Before we added support for the
# special string-typed anchor values, clients would pass
# anchor=None and use_first_unread_anchor=True to indicate
# what is now expressed as anchor="first_unread".
return None
if anchor_val is None:
# Throw an exception if neither an anchor argument not
# use_first_unread_anchor was specified.
raise JsonableError(_("Missing 'anchor' argument."))
if anchor_val == "oldest":
return 0
if anchor_val == "newest":
return LARGER_THAN_MAX_MESSAGE_ID
if anchor_val == "first_unread":
return None
try:
# We don't use `.isnumeric()` to support negative numbers for
# anchor. We don't recommend it in the API (if you want the
# very first message, use 0 or 1), but it used to be supported
# and was used by the web app, so we need to continue
# supporting it for backwards-compatibility
anchor = int(anchor_val)
if anchor < 0:
return 0
elif anchor > LARGER_THAN_MAX_MESSAGE_ID:
return LARGER_THAN_MAX_MESSAGE_ID
return anchor
except ValueError:
raise JsonableError(_("Invalid anchor"))
def limit_query_to_range(
query: Select,
num_before: int,
num_after: int,
anchor: int,
include_anchor: bool,
anchored_to_left: bool,
anchored_to_right: bool,
id_col: ColumnElement[Integer],
first_visible_message_id: int,
) -> SelectBase:
"""
This code is actually generic enough that we could move it to a
library, but our only caller for now is message search.
"""
need_before_query = (not anchored_to_left) and (num_before > 0)
need_after_query = (not anchored_to_right) and (num_after > 0)
need_both_sides = need_before_query and need_after_query
# The semantics of our flags are as follows:
#
# num_before = number of rows < anchor
# num_after = number of rows > anchor
#
# But we may also want the row where id == anchor (if it exists),
# and we don't want to union up to 3 queries. So in some cases
# we do things like `after_limit = num_after + 1` to grab the
# anchor row in the "after" query.
#
# Note that in some cases, if the anchor row isn't found, we
# actually may fetch an extra row at one of the extremes.
if need_both_sides:
before_anchor = anchor - 1
after_anchor = max(anchor, first_visible_message_id)
before_limit = num_before
after_limit = num_after + 1
elif need_before_query:
before_anchor = anchor - (not include_anchor)
before_limit = num_before
if not anchored_to_right:
before_limit += include_anchor
elif need_after_query:
after_anchor = max(anchor + (not include_anchor), first_visible_message_id)
after_limit = num_after + include_anchor
if need_before_query:
before_query = query
if not anchored_to_right:
before_query = before_query.where(id_col <= before_anchor)
before_query = before_query.order_by(id_col.desc())
before_query = before_query.limit(before_limit)
if need_after_query:
after_query = query
if not anchored_to_left:
after_query = after_query.where(id_col >= after_anchor)
after_query = after_query.order_by(id_col.asc())
after_query = after_query.limit(after_limit)
if need_both_sides:
return union_all(before_query.self_group(), after_query.self_group())
elif need_before_query:
return before_query
elif need_after_query:
return after_query
else:
# If we don't have either a before_query or after_query, it's because
# some combination of num_before/num_after/anchor are zero or
# use_first_unread_anchor logic found no unread messages.
#
# The most likely reason is somebody is doing an id search, so searching
# for something like `message_id = 42` is exactly what we want. In other
# cases, which could possibly be buggy API clients, at least we will
# return at most one row here.
return query.where(id_col == anchor)
MessageRowT = TypeVar("MessageRowT", bound=Sequence[Any])
@dataclass
class LimitedMessages(Generic[MessageRowT]):
rows: List[MessageRowT]
found_anchor: bool
found_newest: bool
found_oldest: bool
history_limited: bool
def post_process_limited_query(
rows: Sequence[MessageRowT],
num_before: int,
num_after: int,
anchor: int,
anchored_to_left: bool,
anchored_to_right: bool,
first_visible_message_id: int,
) -> LimitedMessages[MessageRowT]:
# Our queries may have fetched extra rows if they added
# "headroom" to the limits, but we want to truncate those
# rows.
#
# Also, in cases where we had non-zero values of num_before or
# num_after, we want to know found_oldest and found_newest, so
# that the clients will know that they got complete results.
if first_visible_message_id > 0:
visible_rows: Sequence[MessageRowT] = [r for r in rows if r[0] >= first_visible_message_id]
else:
visible_rows = rows
rows_limited = len(visible_rows) != len(rows)
if anchored_to_right:
num_after = 0
before_rows = visible_rows[:]
anchor_rows = []
after_rows = []
else:
before_rows = [r for r in visible_rows if r[0] < anchor]
anchor_rows = [r for r in visible_rows if r[0] == anchor]
after_rows = [r for r in visible_rows if r[0] > anchor]
if num_before:
before_rows = before_rows[-1 * num_before :]
if num_after:
after_rows = after_rows[:num_after]
limited_rows = [*before_rows, *anchor_rows, *after_rows]
found_anchor = len(anchor_rows) == 1
found_oldest = anchored_to_left or (len(before_rows) < num_before)
found_newest = anchored_to_right or (len(after_rows) < num_after)
# BUG: history_limited is incorrect False in the event that we had
# to bump `anchor` up due to first_visible_message_id, and there
# were actually older messages. This may be a rare event in the
# context where history_limited is relevant, because it can only
# happen in one-sided queries with no num_before (see tests tagged
# BUG in PostProcessTest for examples), and we don't generally do
# those from the UI, so this might be OK for now.
#
# The correct fix for this probably involves e.g. making a
# `before_query` when we increase `anchor` just to confirm whether
# messages were hidden.
history_limited = rows_limited and found_oldest
return LimitedMessages(
rows=limited_rows,
found_anchor=found_anchor,
found_newest=found_newest,
found_oldest=found_oldest,
history_limited=history_limited,
)
@dataclass
class FetchedMessages(LimitedMessages[Row]):
anchor: int
include_history: bool
is_search: bool
def fetch_messages(
*,
narrow: OptionalNarrowListT,
user_profile: Optional[UserProfile],
realm: Realm,
is_web_public_query: bool,
anchor: Optional[int],
include_anchor: bool,
num_before: int,
num_after: int,
) -> FetchedMessages:
include_history = ok_to_include_history(narrow, user_profile, is_web_public_query)
if include_history:
# The initial query in this case doesn't use `zerver_usermessage`,
# and isn't yet limited to messages the user is entitled to see!
#
# This is OK only because we've made sure this is a narrow that
# will cause us to limit the query appropriately elsewhere.
# See `ok_to_include_history` for details.
#
# Note that is_web_public_query=True goes here, since
# include_history is semantically correct for is_web_public_query.
need_message = True
need_user_message = False
elif narrow is None:
# We need to limit to messages the user has received, but we don't actually
# need any fields from Message
need_message = False
need_user_message = True
else:
need_message = True
need_user_message = True
query: SelectBase
query, inner_msg_id_col = get_base_query_for_search(
user_profile=user_profile,
need_message=need_message,
need_user_message=need_user_message,
)
query, is_search = add_narrow_conditions(
user_profile=user_profile,
inner_msg_id_col=inner_msg_id_col,
query=query,
narrow=narrow,
realm=realm,
is_web_public_query=is_web_public_query,
)
with get_sqlalchemy_connection() as sa_conn:
if anchor is None:
# `anchor=None` corresponds to the anchor="first_unread" parameter.
anchor = find_first_unread_anchor(
sa_conn,
user_profile,
narrow,
)
anchored_to_left = anchor == 0
# Set value that will be used to short circuit the after_query
# altogether and avoid needless conditions in the before_query.
anchored_to_right = anchor >= LARGER_THAN_MAX_MESSAGE_ID
if anchored_to_right:
num_after = 0
first_visible_message_id = get_first_visible_message_id(realm)
query = limit_query_to_range(
query=query,
num_before=num_before,
num_after=num_after,
anchor=anchor,
include_anchor=include_anchor,
anchored_to_left=anchored_to_left,
anchored_to_right=anchored_to_right,
id_col=inner_msg_id_col,
first_visible_message_id=first_visible_message_id,
)
main_query = query.subquery()
query = (
select(*main_query.c)
.select_from(main_query)
.order_by(column("message_id", Integer).asc())
)
# This is a hack to tag the query we use for testing
query = query.prefix_with("/* get_messages */")
rows = list(sa_conn.execute(query).fetchall())
query_info = post_process_limited_query(
rows=rows,
num_before=num_before,
num_after=num_after,
anchor=anchor,
anchored_to_left=anchored_to_left,
anchored_to_right=anchored_to_right,
first_visible_message_id=first_visible_message_id,
)
return FetchedMessages(
rows=query_info.rows,
found_anchor=query_info.found_anchor,
found_newest=query_info.found_newest,
found_oldest=query_info.found_oldest,
history_limited=query_info.history_limited,
anchor=anchor,
include_history=include_history,
is_search=is_search,
)