presence: Return some presence params in the /register response.

api_docs/changelog.md

@@ -20,6 +20,12 @@ format used by the Zulip server that they are interacting with.
 
 ## Changes in Zulip 7.0
 
+**Feature level 164**
+
+* [`POST /register`](/api/register-queue) Added the
+  `server_presence_ping_interval_seconds` and `server_presence_offline_threshold_seconds`
+  attributes.
+
 **Feature level 163**
 
 * [`GET /users`](/api/get-users), [`GET /users/{user_id}`](/api/get-user),

version.py

@@ -33,7 +33,7 @@ DESKTOP_WARNING_VERSION = "5.4.3"
 # 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 = 163
+API_FEATURE_LEVEL = 164
 
 # 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

zerver/lib/events.py

@@ -354,6 +354,10 @@ def fetch_initial_state_data(
                 realm.demo_organization_scheduled_deletion_date
             )
 
+        # Presence system parameters for client behavior.
+        state["server_presence_ping_interval_seconds"] = settings.PRESENCE_PING_INTERVAL_SECS
+        state["server_presence_offline_threshold_seconds"] = settings.OFFLINE_THRESHOLD_SECS
+
     if want("realm_user_settings_defaults"):
         realm_user_default = RealmUserDefault.objects.get(realm=realm)
         state["realm_user_settings_defaults"] = {}

zerver/openapi/zulip.yaml

@@ -10260,6 +10260,31 @@ paths:
 
                           **Changes**: New in Zulip 4.0 (feature level 53). Previously,
                           this property always had a value of 10000.
+                      server_presence_ping_interval_seconds:
+                        type: integer
+                        description: |
+                          For clients implementing the [presence](/api/get-presence) system,
+                          the time interval the client should use for sending presence requests
+                          to the server (and thus receive presence updates from the server).
+
+                          It is important for presence implementatios to use both this and
+                          `server_presence_offline_threshold_seconds` correctly, so that a Zulip
+                          server can change these values to manage the trade-off between load and
+                          freshness of presence data.
+
+                          **Changes**: New in Zulip 7.0 (feature level 164). Clients should use 60
+                          for older Zulip servers, since that's the value that was hardcoded in the
+                          the Zulip mobile apps prior to this parameter being introduced.
+                      server_presence_offline_threshold_seconds:
+                        type: integer
+                        description: |
+                          How old a presence timestamp for a given user can be before the user
+                          should be displayed as offline by clients displaying Zulip presence
+                          data. See the related `server_presence_ping_interval_seconds` for details.
+
+                          **Changes**: New in Zulip 7.0 (feature level 164). Clients should use 140
+                          for older Zulip servers, since that's the value that was hardcoded in the
+                          Zulip client apps prior to this parameter being introduced.
                       muted_topics:
                         type: array
                         deprecated: true

zerver/tests/test_home.py

@@ -196,6 +196,8 @@ class HomeTest(ZulipTestCase):
         "server_inline_url_embed_preview",
         "server_name_changes_disabled",
         "server_needs_upgrade",
+        "server_presence_offline_threshold_seconds",
+        "server_presence_ping_interval_seconds",
         "server_timestamp",
         "server_web_public_streams_enabled",
         "settings_send_digest_emails",

zproject/default_settings.py

@@ -491,6 +491,9 @@ STAGING = False
 # Should match the presence.js constant.
 OFFLINE_THRESHOLD_SECS = 140
 
+# How often a client should ping by asking for presence data of all users.
+PRESENCE_PING_INTERVAL_SECS = 50
+
 # Specifies the number of active users in the realm
 # above which sending of presence update events will be disabled.
 USER_LIMIT_FOR_SENDING_PRESENCE_UPDATE_EVENTS = 100