streams: Pass stream_weekly_traffic field in stream objects.

This commit adds code to pass stream traffic data using
the "stream_weekly_traffic" field in stream objects.

We already include the traffic data in Subscription objects,
but the traffic data does not depend on the user to stream
relationship and is stream-only information, so it's better
to include it in Stream objects. We may remove the traffic
data and other stream information fields for Subscription
objects in future.

This will help clients to correctly display the stream
traffic data in case where client receives a stream
creation event and no subscription event, for an already
existing stream which the user did not have access to before.

api_docs/changelog.md

@@ -20,6 +20,14 @@ format used by the Zulip server that they are interacting with.
 
 ## Changes in Zulip 8.0
 
+**Feature level 199**
+
+* [`POST /register`](/api/register-queue), [`GET /events`][/api/get-events],
+  [`GET /streams`](/api/get-streams),
+  [`GET /streams/{stream_id}`](/api/get-stream-by-id): Stream objects now
+  include a `stream_weekly_traffic` field indicating the stream's level of
+  traffic.
+
 **Feature level 198**
 
 * [`GET /events`](/api/get-events), [`POST /register`](/api/register-queue),

version.py

@@ -33,7 +33,7 @@ DESKTOP_WARNING_VERSION = "5.9.3"
 # Changes should be accompanied by documentation explaining what the
 # new level means in api_docs/changelog.md, as well as "**Changes**"
 # entries in the endpoint's documentation in `zulip.yaml`.
-API_FEATURE_LEVEL = 198
+API_FEATURE_LEVEL = 199
 
 # Bump the minor PROVISION_VERSION to indicate that folks should provision
 # only when going from an old version of the code to a newer version. Bump

web/tests/lib/events.js

@@ -650,13 +650,31 @@ exports.fixtures = {
     stream__create: {
         type: "stream",
         op: "create",
-        streams: [streams.devel, streams.test],
+        streams: [
+            {
+                ...streams.devel,
+                stream_weekly_traffic: null,
+            },
+            {
+                ...streams.test,
+                stream_weekly_traffic: null,
+            },
+        ],
     },
 
     stream__delete: {
         type: "stream",
         op: "delete",
-        streams: [streams.devel, streams.test],
+        streams: [
+            {
+                ...streams.devel,
+                stream_weekly_traffic: null,
+            },
+            {
+                ...streams.test,
+                stream_weekly_traffic: null,
+            },
+        ],
     },
 
     stream__update: {

zerver/actions/streams.py

@@ -37,7 +37,7 @@ from zerver.lib.stream_subscription import (
     get_bulk_stream_subscriber_info,
     get_used_colors_for_user_ids,
 )
-from zerver.lib.stream_traffic import get_average_weekly_stream_traffic, get_streams_traffic
+from zerver.lib.stream_traffic import get_streams_traffic
 from zerver.lib.streams import (
     can_access_stream_user_ids,
     get_occupied_streams,
@@ -210,10 +210,15 @@ def do_reactivate_stream(
         event_time=timezone_now(),
     )
 
+    recent_traffic = None
+    if not realm.is_zephyr_mirror_realm:
+        # We do not need stream traffic data for streams in zephyr mirroring realm.
+        recent_traffic = get_streams_traffic({stream.id})
+
     # All admins always get to know about private streams' existence,
     # but we only subscribe the realm owners.
     send_stream_creation_event(
-        realm, stream, [user.id for user in realm.get_admin_users_and_bots()]
+        realm, stream, [user.id for user in realm.get_admin_users_and_bots()], recent_traffic
     )
     bulk_add_subscriptions(
         realm=realm,
@@ -313,7 +318,6 @@ def get_subscriber_ids(
 @dataclass
 class StreamInfo:
     email_address: str
-    stream_weekly_traffic: Optional[int]
     subscribers: List[int]
 
 
@@ -336,16 +340,12 @@ def send_subscription_add_events(
         stream = sub_info.stream
         if stream.id not in stream_info_dict:
             email_address = encode_email_address(stream, show_sender=True)
-            stream_weekly_traffic = get_average_weekly_stream_traffic(
-                stream.id, stream.date_created, recent_traffic
-            )
             if stream.is_in_zephyr_realm and not stream.invite_only:
                 subscribers = []
             else:
                 subscribers = list(subscriber_dict[stream.id])
             stream_info_dict[stream.id] = StreamInfo(
                 email_address=email_address,
-                stream_weekly_traffic=stream_weekly_traffic,
                 subscribers=subscribers,
             )
 
@@ -355,7 +355,7 @@ def send_subscription_add_events(
             stream = sub_info.stream
             stream_info = stream_info_dict[stream.id]
             subscription = sub_info.sub
-            stream_dict = stream_to_dict(stream)
+            stream_dict = stream_to_dict(stream, recent_traffic)
             # This is verbose as we cannot unpack existing TypedDict
             # to initialize another TypedDict while making mypy happy.
             # https://github.com/python/mypy/issues/5382
@@ -372,7 +372,7 @@ def send_subscription_add_events(
                 # Computed fields not present in Subscription.API_FIELDS
                 email_address=stream_info.email_address,
                 in_home_view=not subscription.is_muted,
-                stream_weekly_traffic=stream_info.stream_weekly_traffic,
+                stream_weekly_traffic=stream_dict["stream_weekly_traffic"],
                 subscribers=stream_info.subscribers,
                 # Fields from Stream.API_FIELDS
                 can_remove_subscribers_group=stream_dict["can_remove_subscribers_group"],
@@ -452,6 +452,12 @@ def send_stream_creation_events_for_previously_inaccessible_streams(
     altered_user_dict: Dict[int, Set[int]],
     altered_guests: Set[int],
 ) -> None:
+    recent_traffic = None
+    if not realm.is_zephyr_mirror_realm:
+        # We do not need stream traffic data for streams in zephyr mirroring realm.
+        stream_ids = set(altered_user_dict.keys())
+        recent_traffic = get_streams_traffic(stream_ids)
+
     for stream_id, stream_users_ids in altered_user_dict.items():
         stream = stream_dict[stream_id]
 
@@ -472,7 +478,7 @@ def send_stream_creation_events_for_previously_inaccessible_streams(
             notify_user_ids = list(stream_users_ids & altered_guests)
 
         if notify_user_ids:
-            send_stream_creation_event(realm, stream, notify_user_ids)
+            send_stream_creation_event(realm, stream, notify_user_ids, recent_traffic)
 
 
 def send_peer_subscriber_events(
@@ -1058,7 +1064,12 @@ def do_change_stream_permission(
         )
         non_guest_user_ids = set(active_non_guest_user_ids(stream.realm_id))
         notify_stream_creation_ids = non_guest_user_ids - old_can_access_stream_user_ids
-        send_stream_creation_event(realm, stream, list(notify_stream_creation_ids))
+
+        recent_traffic = None
+        if not realm.is_zephyr_mirror_realm:
+            # We do not need stream traffic data for streams in zephyr mirroing realm.
+            recent_traffic = get_streams_traffic({stream.id})
+        send_stream_creation_event(realm, stream, list(notify_stream_creation_ids), recent_traffic)
 
         # Add subscribers info to the stream object. We need to send peer_add
         # events to users who were previously subscribed to the streams as

zerver/lib/default_streams.py

@@ -1,6 +1,6 @@
 from typing import List, Set
 
-from zerver.lib.types import APIStreamDict
+from zerver.lib.types import DefaultStreamDict
 from zerver.models import DefaultStream, Stream
 
 
@@ -22,7 +22,7 @@ def get_default_stream_ids_for_realm(realm_id: int) -> Set[int]:
     return set(DefaultStream.objects.filter(realm_id=realm_id).values_list("stream_id", flat=True))
 
 
-def get_default_streams_for_realm_as_dicts(realm_id: int) -> List[APIStreamDict]:
+def get_default_streams_for_realm_as_dicts(realm_id: int) -> List[DefaultStreamDict]:
     """
     Return all the default streams for a realm using a list of dictionaries sorted
     by stream name.

zerver/lib/event_schema.py

@@ -49,7 +49,7 @@ from zerver.models import Realm, RealmUserDefault, Stream, UserProfile
 
 # These fields are used for "stream" events, and are included in the
 # larger "subscription" events that also contain personal settings.
-basic_stream_fields = [
+default_stream_fields = [
     ("can_remove_subscribers_group", int),
     ("date_created", int),
     ("description", str),
@@ -65,6 +65,11 @@ basic_stream_fields = [
     ("stream_post_policy", int),
 ]
 
+basic_stream_fields = [
+    *default_stream_fields,
+    ("stream_weekly_traffic", OptionalType(int)),
+]
+
 subscription_fields: Sequence[Tuple[str, object]] = [
     *basic_stream_fields,
     ("audible_notifications", OptionalType(bool)),
@@ -76,7 +81,6 @@ subscription_fields: Sequence[Tuple[str, object]] = [
     ("is_muted", bool),
     ("pin_to_top", bool),
     ("push_notifications", OptionalType(bool)),
-    ("stream_weekly_traffic", OptionalType(int)),
     # We may try to remove subscribers from some events in
     # the future for clients that don't want subscriber
     # info.
@@ -185,7 +189,7 @@ _check_stream_group = DictType(
         ("name", str),
         ("id", int),
         ("description", str),
-        ("streams", ListType(DictType(basic_stream_fields))),
+        ("streams", ListType(DictType(default_stream_fields))),
     ]
 )
 
@@ -200,7 +204,7 @@ check_default_stream_groups = make_checker(default_stream_groups_event)
 default_streams_event = event_dict_type(
     required_keys=[
         ("type", Equals("default_streams")),
-        ("default_streams", ListType(DictType(basic_stream_fields))),
+        ("default_streams", ListType(DictType(default_stream_fields))),
     ]
 )
 check_default_streams = make_checker(default_streams_event)

zerver/lib/events.py

@@ -998,12 +998,6 @@ def apply_event(
                     if include_subscribers:
                         stream_data["subscribers"] = []
 
-                    # We know the stream has no traffic, and this
-                    # field is not present in the event.
-                    #
-                    # TODO: Probably this should just be added to the event.
-                    stream_data["stream_weekly_traffic"] = None
-
                     # Add stream to never_subscribed (if not invite_only)
                     state["never_subscribed"].append(stream_data)
                 if "streams" in state:

zerver/lib/streams.py

@@ -1,4 +1,4 @@
-from typing import Collection, List, Optional, Set, Tuple, TypedDict, Union
+from typing import Collection, Dict, List, Optional, Set, Tuple, TypedDict, Union
 
 from django.db import transaction
 from django.db.models import Exists, OuterRef, Q, QuerySet
@@ -16,6 +16,7 @@ from zerver.lib.stream_subscription import (
     get_active_subscriptions_for_stream_id,
     get_subscribed_stream_ids_for_user,
 )
+from zerver.lib.stream_traffic import get_average_weekly_stream_traffic, get_streams_traffic
 from zerver.lib.string_validation import check_stream_name
 from zerver.lib.timestamp import datetime_to_timestamp
 from zerver.lib.types import APIStreamDict
@@ -111,8 +112,13 @@ def render_stream_description(text: str, realm: Realm) -> str:
     return markdown_convert(text, message_realm=realm, no_previews=True).rendered_content
 
 
-def send_stream_creation_event(realm: Realm, stream: Stream, user_ids: List[int]) -> None:
+def send_stream_creation_event(
-    event = dict(type="stream", op="create", streams=[stream_to_dict(stream)])
+    realm: Realm,
+    stream: Stream,
+    user_ids: List[int],
+    recent_traffic: Optional[Dict[int, int]] = None,
+) -> None:
+    event = dict(type="stream", op="create", streams=[stream_to_dict(stream, recent_traffic)])
     send_event(realm, event, user_ids)
 
 
@@ -826,7 +832,22 @@ def get_occupied_streams(realm: Realm) -> QuerySet[Stream]:
     return occupied_streams
 
 
-def stream_to_dict(stream: Stream) -> APIStreamDict:
+def stream_to_dict(
+    stream: Stream, recent_traffic: Optional[Dict[int, int]] = None
+) -> APIStreamDict:
+    if recent_traffic is not None:
+        stream_weekly_traffic = get_average_weekly_stream_traffic(
+            stream.id, stream.date_created, recent_traffic
+        )
+    else:
+        # We cannot compute the traffic data for a newly created
+        # stream, so we set "stream_weekly_traffic" field to
+        # "None" for the stream object in creation event.
+        # Also, there are some cases where we do not need to send
+        # the traffic data, like when deactivating a stream, and
+        # passing stream data to spectators.
+        stream_weekly_traffic = None
+
     return APIStreamDict(
         can_remove_subscribers_group=stream.can_remove_subscribers_group_id,
         date_created=datetime_to_timestamp(stream.date_created),
@@ -841,6 +862,7 @@ def stream_to_dict(stream: Stream) -> APIStreamDict:
         stream_id=stream.id,
         stream_post_policy=stream.stream_post_policy,
         is_announcement_only=stream.stream_post_policy == Stream.STREAM_POST_POLICY_ADMINS,
+        stream_weekly_traffic=stream_weekly_traffic,
     )
 
 
@@ -914,7 +936,13 @@ def do_get_streams(
             # Don't bother going to the database with no valid sources
             return []
 
-    stream_dicts = [stream_to_dict(stream) for stream in streams]
+    recent_traffic = None
+    if not user_profile.realm.is_zephyr_mirror_realm:
+        # We do not need stream traffic data for streams in zephyr mirroring realm.
+        stream_ids = {stream.id for stream in streams}
+        recent_traffic = get_streams_traffic(stream_ids)
+
+    stream_dicts = [stream_to_dict(stream, recent_traffic) for stream in streams]
     stream_dicts.sort(key=lambda elt: elt["name"])
 
     if include_default:

zerver/lib/types.py

@@ -217,7 +217,7 @@ class NeverSubscribedStreamDict(TypedDict):
     subscribers: NotRequired[List[int]]
 
 
-class APIStreamDict(TypedDict):
+class DefaultStreamDict(TypedDict):
     """Stream information provided to Zulip clients as a dictionary via API.
     It should contain all the fields specified in `zerver.models.Stream.API_FIELDS`
     with few exceptions and possible additional fields.
@@ -240,6 +240,10 @@ class APIStreamDict(TypedDict):
     is_default: NotRequired[bool]
 
 
+class APIStreamDict(DefaultStreamDict):
+    stream_weekly_traffic: Optional[int]
+
+
 class APISubscriptionDict(APIStreamDict):
     """Similar to StreamClientDict, it should contain all the fields specified in
     `zerver.models.Subscription.API_FIELDS` and several additional fields.
@@ -256,7 +260,6 @@ class APISubscriptionDict(APIStreamDict):
     # Computed fields not specified in `Subscription.API_FIELDS`
     email_address: str
     in_home_view: bool
-    stream_weekly_traffic: Optional[int]
     subscribers: List[int]
 
 

zerver/models.py

@@ -86,7 +86,7 @@ from zerver.lib.exceptions import JsonableError, RateLimitedError
 from zerver.lib.pysa import mark_sanitized
 from zerver.lib.timestamp import datetime_to_timestamp
 from zerver.lib.types import (
-    APIStreamDict,
+    DefaultStreamDict,
     DisplayRecipientT,
     ExtendedFieldElement,
     ExtendedValidator,
@@ -2701,8 +2701,8 @@ class Stream(models.Model):
         "can_remove_subscribers_group_id",
     ]
 
-    def to_dict(self) -> APIStreamDict:
+    def to_dict(self) -> DefaultStreamDict:
-        return APIStreamDict(
+        return DefaultStreamDict(
             can_remove_subscribers_group=self.can_remove_subscribers_group_id,
             date_created=datetime_to_timestamp(self.date_created),
             description=self.description,

zerver/openapi/zulip.yaml

@@ -1884,7 +1884,7 @@ paths:
                                     An array of dictionaries where each dictionary
                                     contains details about a single default stream.
                                   items:
-                                    $ref: "#/components/schemas/BasicStream"
+                                    $ref: "#/components/schemas/DefaultStream"
                               example:
                                 {
                                   "type": "default_streams",
@@ -11766,7 +11766,7 @@ paths:
                       realm_default_streams:
                         type: array
                         items:
-                          $ref: "#/components/schemas/BasicStream"
+                          $ref: "#/components/schemas/DefaultStream"
                         description: |
                           Present if `default_streams` is present in `fetch_event_types`.
 
@@ -15689,6 +15689,21 @@ paths:
                                   nullable: true
                                 is_announcement_only: {}
                                 can_remove_subscribers_group: {}
+                                stream_weekly_traffic:
+                                  type: integer
+                                  nullable: true
+                                  description: |
+                                    The average number of messages sent to the stream per week, as
+                                    estimated based on recent weeks, rounded to the nearest integer.
+
+                                    If `null`, no information is provided on the average traffic.
+                                    This can be because the stream was recently created and there
+                                    is insufficient data to make an estimate, or because the server
+                                    wishes to omit this information for this client, this realm, or
+                                    this endpoint or type of event.
+
+                                    **Changes**: New in Zulip 8.0 (feature level 199). Previously,
+                                    this statistic was available only in subscription objects.
                                 is_default:
                                   type: boolean
                                   description: |
@@ -16976,6 +16991,41 @@ components:
                   The unique message ID. Messages should always be
                   displayed sorted by ID.
     BasicStream:
+      allOf:
+        - $ref: "#/components/schemas/BasicStreamBase"
+        - additionalProperties: false
+          properties:
+            stream_id: {}
+            name: {}
+            description: {}
+            date_created: {}
+            invite_only: {}
+            rendered_description: {}
+            is_web_public: {}
+            stream_post_policy: {}
+            message_retention_days:
+              nullable: true
+            history_public_to_subscribers: {}
+            first_message_id:
+              nullable: true
+            is_announcement_only: {}
+            can_remove_subscribers_group: {}
+            stream_weekly_traffic:
+              type: integer
+              nullable: true
+              description: |
+                The average number of messages sent to the stream per week, as
+                estimated based on recent weeks, rounded to the nearest integer.
+
+                If `null`, no information is provided on the average traffic.
+                This can be because the stream was recently created and there
+                is insufficient data to make an estimate, or because the server
+                wishes to omit this information for this client, this realm, or
+                this endpoint or type of event.
+
+                **Changes**: New in Zulip 8.0 (feature level 199). Previously, this
+                statistic was available only in subscription objects.
+    DefaultStream:
       allOf:
         - $ref: "#/components/schemas/BasicStreamBase"
         - additionalProperties: false
@@ -17786,7 +17836,7 @@ components:
             Array containing details about the streams
             in the default stream group.
           items:
-            $ref: "#/components/schemas/BasicStream"
+            $ref: "#/components/schemas/DefaultStream"
     EmailAddressVisibility:
       type: integer
       description: |

zerver/tests/test_event_system.py

@@ -1249,7 +1249,7 @@ class FetchQueriesTest(ZulipTestCase):
         self.login_user(user)
 
         flush_per_request_caches()
-        with self.assert_database_query_count(38):
+        with self.assert_database_query_count(39):
             with mock.patch("zerver.lib.events.always_want") as want_mock:
                 fetch_initial_state_data(user)
 
@@ -1279,7 +1279,7 @@ class FetchQueriesTest(ZulipTestCase):
             recent_private_conversations=1,
             scheduled_messages=1,
             starred_messages=1,
-            stream=2,
+            stream=3,
             stop_words=0,
             subscription=4,
             update_display_settings=0,

zerver/tests/test_events.py

@@ -2476,6 +2476,7 @@ class NormalActionsTest(BaseAction):
             action = lambda: do_deactivate_stream(stream, acting_user=None)
             events = self.verify_action(action, include_streams=include_streams)
             check_stream_delete("events[0]", events[0])
+            self.assertIsNone(events[0]["streams"][0]["stream_weekly_traffic"])
 
     def test_subscribe_other_user_never_subscribed(self) -> None:
         for i, include_streams in enumerate([True, False]):
@@ -3266,6 +3267,7 @@ class SubscribeActionTest(BaseAction):
             events[0]["streams"][0]["message_retention_days"],
             10,
         )
+        self.assertIsNone(events[0]["streams"][0]["stream_weekly_traffic"])
 
         stream.invite_only = False
         stream.save()

zerver/tests/test_subs.py

@@ -230,7 +230,7 @@ class TestMiscStuff(ZulipTestCase):
         expected_fields |= {"can_remove_subscribers_group"}
 
         stream_dict_fields = set(APIStreamDict.__annotations__.keys())
-        computed_fields = {"is_announcement_only", "is_default"}
+        computed_fields = {"is_announcement_only", "is_default", "stream_weekly_traffic"}
 
         self.assertEqual(stream_dict_fields - computed_fields, expected_fields)
 
@@ -262,6 +262,7 @@ class TestCreateStreams(ZulipTestCase):
         # Send public stream creation event to all active users.
         self.assertEqual(events[0]["users"], active_non_guest_user_ids(realm.id))
         self.assertEqual(events[0]["event"]["streams"][0]["name"], "Public stream")
+        self.assertEqual(events[0]["event"]["streams"][0]["stream_weekly_traffic"], None)
 
         with self.capture_send_event_calls(expected_num_events=1) as events:
             ensure_stream(realm, "Private stream", invite_only=True, acting_user=None)
@@ -273,6 +274,7 @@ class TestCreateStreams(ZulipTestCase):
         self.assertTrue(self.example_user("iago").id in events[0]["users"])
         self.assertTrue(self.example_user("desdemona").id in events[0]["users"])
         self.assertEqual(events[0]["event"]["streams"][0]["name"], "Private stream")
+        self.assertEqual(events[0]["event"]["streams"][0]["stream_weekly_traffic"], None)
 
         moderators_system_group = UserGroup.objects.get(
             name="role:moderators", realm=realm, is_system_group=True
@@ -4528,7 +4530,7 @@ class SubscriptionAPITest(ZulipTestCase):
         streams_to_sub = ["multi_user_stream"]
         flush_per_request_caches()
         with self.capture_send_event_calls(expected_num_events=5) as events:
-            with self.assert_database_query_count(36):
+            with self.assert_database_query_count(37):
                 self.common_subscribe_to_streams(
                     self.test_user,
                     streams_to_sub,
@@ -4552,7 +4554,7 @@ class SubscriptionAPITest(ZulipTestCase):
 
         # Now add ourselves
         with self.capture_send_event_calls(expected_num_events=2) as events:
-            with self.assert_database_query_count(12):
+            with self.assert_database_query_count(13):
                 self.common_subscribe_to_streams(
                     self.test_user,
                     streams_to_sub,
@@ -4982,7 +4984,7 @@ class SubscriptionAPITest(ZulipTestCase):
 
         test_user_ids = [user.id for user in test_users]
 
-        with self.assert_database_query_count(20):
+        with self.assert_database_query_count(21):
             with cache_tries_captured() as cache_tries:
                 with mock.patch("zerver.views.streams.send_messages_for_new_subscribers"):
                     self.common_subscribe_to_streams(
@@ -5456,7 +5458,7 @@ class SubscriptionAPITest(ZulipTestCase):
         ]
 
         # Test creating a public stream when realm does not have a notification stream.
-        with self.assert_database_query_count(36):
+        with self.assert_database_query_count(37):
             self.common_subscribe_to_streams(
                 self.test_user,
                 [new_streams[0]],
@@ -5464,7 +5466,7 @@ class SubscriptionAPITest(ZulipTestCase):
             )
 
         # Test creating private stream.
-        with self.assert_database_query_count(35):
+        with self.assert_database_query_count(36):
             self.common_subscribe_to_streams(
                 self.test_user,
                 [new_streams[1]],
@@ -5476,7 +5478,7 @@ class SubscriptionAPITest(ZulipTestCase):
         notifications_stream = get_stream(self.streams[0], self.test_realm)
         self.test_realm.notifications_stream_id = notifications_stream.id
         self.test_realm.save()
-        with self.assert_database_query_count(44):
+        with self.assert_database_query_count(45):
             self.common_subscribe_to_streams(
                 self.test_user,
                 [new_streams[2]],
@@ -5897,7 +5899,7 @@ class GetSubscribersTest(ZulipTestCase):
             polonius.id,
         ]
 
-        with self.assert_database_query_count(47):
+        with self.assert_database_query_count(48):
             self.common_subscribe_to_streams(
                 self.user_profile,
                 streams,

zerver/views/streams.py

@@ -58,6 +58,7 @@ from zerver.lib.request import REQ, has_request_variables
 from zerver.lib.response import json_partial_success, json_success
 from zerver.lib.retention import STREAM_MESSAGE_BATCH_SIZE as RETENTION_STREAM_MESSAGE_BATCH_SIZE
 from zerver.lib.retention import parse_message_retention_days
+from zerver.lib.stream_traffic import get_streams_traffic
 from zerver.lib.streams import (
     StreamDict,
     access_default_stream_group_by_id,
@@ -874,7 +875,12 @@ def get_stream_backend(
     stream_id: int,
 ) -> HttpResponse:
     (stream, sub) = access_stream_by_id(user_profile, stream_id, allow_realm_admin=True)
-    return json_success(request, data={"stream": stream_to_dict(stream)})
+
+    recent_traffic = None
+    if not user_profile.realm.is_zephyr_mirror_realm:
+        # We do not need stream traffic data in zephyr mirroring realm.
+        recent_traffic = get_streams_traffic({stream.id})
+    return json_success(request, data={"stream": stream_to_dict(stream, recent_traffic)})
 
 
 @has_request_variables