This code removes a lot of complexity with very likely
positive overall impact on system performance and
negligible downside.
We already cache display recipients on a per-user
level, so there's no need for another cache layer on
top of that that keys them with recipient ids.
We avoid strange things where Alice/Bob and Bob/Charlie
get put into the top layer cache and then we still have
a cache miss on Alice/Charlie despite the lower level
cache being able to support per-user lookups.
This change does introduce an extra database round trip
if any of our messages have a huddle, but the query is
extremely cheap, and we can always try to cache that
function more directly or try to re-use some of our
other huddle-based caches.
As part of this, we clean up the names for the
lower-level per-user cache of display recipients, and
we simplify the cache keys.
We also stop passing in a full Recipient object to the
`bulk_get_huddle_user_ids` functions.
The local impact of this change should be easy to
measure (at least approximately), since we use this
function every time a user gets messages via the
/messages endpoint.
The only overlap between how we fetched streams and
users was to share some really complicated data
structures.
We can also short-circuit some logic if a message
batch is either all-stream or all-DM.
We restrict the columns, avoid quadratic looping,
and don't bother with order_by.
We also return the user ids (per recipient) as
sets, since that's how the only caller uses the
info (albeit implicitly via set.union accepting
a list).
This demonstrates a way to resolve the long-standing issue
of typing higher-order identity functions without using
`cast` and in a type-safe manner for decorators in `cache.py`.
Signed-off-by: Zixuan James Li <359101898@qq.com>
This was hiding an actual type error in test_cache: a mismatch between
the object ID type, which is str, and the default id_fetcher, which
returns int.
Mypy’s insufficient support for default generic arguments basically
means we can’t use them without a lot of overloading, and there are
not enough callers here to justify that.
https://github.com/python/mypy/issues/3737
We avoid this being super messy where the code calls this by adding
some less generic wrappers for generic_bulk_cached_fetch.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Fixes#2665.
Regenerated by tabbott with `lint --fix` after a rebase and change in
parameters.
Note from tabbott: In a few cases, this converts technical debt in the
form of unsorted imports into different technical debt in the form of
our largest files having very long, ugly import sequences at the
start. I expect this change will increase pressure for us to split
those files, which isn't a bad thing.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Automatically generated by the following script, based on the output
of lint with flake8-comma:
import re
import sys
last_filename = None
last_row = None
lines = []
for msg in sys.stdin:
m = re.match(
r"\x1b\[35mflake8 \|\x1b\[0m \x1b\[1;31m(.+):(\d+):(\d+): (\w+)", msg
)
if m:
filename, row_str, col_str, err = m.groups()
row, col = int(row_str), int(col_str)
if filename == last_filename:
assert last_row != row
else:
if last_filename is not None:
with open(last_filename, "w") as f:
f.writelines(lines)
with open(filename) as f:
lines = f.readlines()
last_filename = filename
last_row = row
line = lines[row - 1]
if err in ["C812", "C815"]:
lines[row - 1] = line[: col - 1] + "," + line[col - 1 :]
elif err in ["C819"]:
assert line[col - 2] == ","
lines[row - 1] = line[: col - 2] + line[col - 1 :].lstrip(" ")
if last_filename is not None:
with open(last_filename, "w") as f:
f.writelines(lines)
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
Generated by `pyupgrade --py3-plus --keep-percent-format` on all our
Python code except `zthumbor` and `zulip-ec2-configure-interfaces`,
followed by manual indentation fixes.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
When we are fetching messages, we need to hydrate
stream names into the messages for legacy reasons.
(Ideally, we could skip this step for the webapp
and modern mobile clients, since they really only
need stream_ids, but we're not there yet.)
We keep a recipient cache that maps recipient ids
to stream names.
When we populate that cache, we now use `values(...)`
to avoid fat objects and extra DB work.
Note that we are already using a similar technique
for hydrating PM/huddle recipients.
There is no need to fetch the entire Stream or UserProfile objects, as
only several fields are needed. We use Django's .values() method to only
get what's needed.
For UserProfiles, it means that we get from the queries are dictionaries
already in the display_recipient form (UserDisplayRecipient type) - so
we can remove the user_profile_to_display_recipient_dict function, as
there's no need for this UserProfile -> UserDisplayRecipient conversion
anymore.
Instead of having the rather unclear type Union[str,
List[UserDisplayRecipient]] where display_recipient of message dicts was
involved, we use DisplayRecipientT (renamed from DisplayRecipientCacheT
- since there wasn't much reason to have the word Cache in there), which
makes it clearer what is the actual nature of the objects and gets rid
of this pretty big type declaration.
Since the display_recipients dictionaries corresponding to users are
always dictionaries with keys email, full_name, short_name, id,
is_mirror_dummy - instead of using the overly general Dict[str, Any]
type, we can define a UserDisplayRecipient type,
using an appropriate TypedDict.
The type definitions are moved from display_recipient.py to types.py, so
that they can be imported in models.py.
Appropriate type adjustments are made in various places in the code
where we operate on display_recipients.
The user information in display_recipient in cached message_dicts
becomes outdated if the information is changed in any way.
In particular, since we don't have a way to find all the message
objects that might contain PMs after an organization toggles the
setting to hide user email addresses from other users, we had a
situation where client might see inaccurate cached data from before
the transition for a period of up to hours.
We address this by using our generic_bulk_cached_fetch toolchain to
ensure we always are fetching display_recipient data from the database
(and/or a special recipient_id -> display_recipient cache, which we
can flush easily).
Fixes#12818.
Steve Howell
Zixuan James Li
Anders Kaseorg
Zixuan James Li
Steve Howell
Anders Kaseorg
Steve Howell
Tim Abbott
Mateusz Mandera