Integrate presence from hotfixes (#3694)

Author: hawkowl

changelog.d/3694.feature

@@ -0,0 +1 @@
+Synapse's presence functionality can now be disabled with the "use_presence" configuration option.

docs/workers.rst

@@ -241,6 +241,14 @@ regular expressions::
 
     ^/_matrix/client/(api/v1|r0|unstable)/keys/upload
 
+If ``use_presence`` is False in the homeserver config, it can also handle REST
+endpoints matching the following regular expressions::
+
+    ^/_matrix/client/(api/v1|r0|unstable)/presence/[^/]+/status
+
+This "stub" presence handler will pass through ``GET`` request but make the
+``PUT`` effectively a no-op.
+
 It will proxy any requests it cannot handle to the main synapse instance. It
 must therefore be configured with the location of the main instance, via
 the ``worker_main_http_uri`` setting in the frontend_proxy worker configuration

synapse/app/_base.py

@@ -140,7 +140,7 @@ def listen_metrics(bind_addresses, port):
         logger.info("Metrics now reporting on %s:%d", host, port)
 
 
-def listen_tcp(bind_addresses, port, factory, backlog=50):
+def listen_tcp(bind_addresses, port, factory, reactor=reactor, backlog=50):
     """
     Create a TCP socket for a port and several addresses
     """
@@ -156,7 +156,9 @@ def listen_tcp(bind_addresses, port, factory, backlog=50):
             check_bind_error(e, address, bind_addresses)
 
 
-def listen_ssl(bind_addresses, port, factory, context_factory, backlog=50):
+def listen_ssl(
+    bind_addresses, port, factory, context_factory, reactor=reactor, backlog=50
+):
     """
     Create an SSL socket for a port and several addresses
     """

synapse/app/frontend_proxy.py

@@ -38,6 +38,7 @@
 from synapse.replication.slave.storage.devices import SlavedDeviceStore
 from synapse.replication.slave.storage.registration import SlavedRegistrationStore
 from synapse.replication.tcp.client import ReplicationClientHandler
+from synapse.rest.client.v1.base import ClientV1RestServlet, client_path_patterns
 from synapse.rest.client.v2_alpha._base import client_v2_patterns
 from synapse.server import HomeServer
 from synapse.storage.engines import create_engine
@@ -49,6 +50,35 @@
 logger = logging.getLogger("synapse.app.frontend_proxy")
 
 
+class PresenceStatusStubServlet(ClientV1RestServlet):
+    PATTERNS = client_path_patterns("/presence/(?P<user_id>[^/]*)/status")
+
+    def __init__(self, hs):
+        super(PresenceStatusStubServlet, self).__init__(hs)
+        self.http_client = hs.get_simple_http_client()
+        self.auth = hs.get_auth()
+        self.main_uri = hs.config.worker_main_http_uri
+
+    @defer.inlineCallbacks
+    def on_GET(self, request, user_id):
+        # Pass through the auth headers, if any, in case the access token
+        # is there.
+        auth_headers = request.requestHeaders.getRawHeaders("Authorization", [])
+        headers = {
+            "Authorization": auth_headers,
+        }
+        result = yield self.http_client.get_json(
+            self.main_uri + request.uri,
+            headers=headers,
+        )
+        defer.returnValue((200, result))
+
+    @defer.inlineCallbacks
+    def on_PUT(self, request, user_id):
+        yield self.auth.get_user_by_req(request)
+        defer.returnValue((200, {}))
+
+
 class KeyUploadServlet(RestServlet):
     PATTERNS = client_v2_patterns("/keys/upload(/(?P<device_id>[^/]+))?$")
 
@@ -135,6 +165,12 @@ def _listen_http(self, listener_config):
                 elif name == "client":
                     resource = JsonResource(self, canonical_json=False)
                     KeyUploadServlet(self).register(resource)
+
+                    # If presence is disabled, use the stub servlet that does
+                    # not allow sending presence
+                    if not self.config.use_presence:
+                        PresenceStatusStubServlet(self).register(resource)
+
                     resources.update({
                         "/_matrix/client/r0": resource,
                         "/_matrix/client/unstable": resource,
@@ -153,7 +189,8 @@ def _listen_http(self, listener_config):
                 listener_config,
                 root_resource,
                 self.version_string,
-            )
+            ),
+            reactor=self.get_reactor()
         )
 
         logger.info("Synapse client reader now listening on port %d", port)

synapse/app/synchrotron.py

@@ -114,7 +114,10 @@ def __init__(self, hs):
         logger.info("Presence process_id is %r", self.process_id)
 
     def send_user_sync(self, user_id, is_syncing, last_sync_ms):
-        self.hs.get_tcp_replication().send_user_sync(user_id, is_syncing, last_sync_ms)
+        if self.hs.config.use_presence:
+            self.hs.get_tcp_replication().send_user_sync(
+                user_id, is_syncing, last_sync_ms
+            )
 
     def mark_as_coming_online(self, user_id):
         """A user has started syncing. Send a UserSync to the master, unless they
@@ -211,10 +214,13 @@ def process_replication_rows(self, token, rows):
         yield self.notify_from_replication(states, stream_id)
 
     def get_currently_syncing_users(self):
-        return [
-            user_id for user_id, count in iteritems(self.user_to_num_current_syncs)
-            if count > 0
-        ]
+        if self.hs.config.use_presence:
+            return [
+                user_id for user_id, count in iteritems(self.user_to_num_current_syncs)
+                if count > 0
+            ]
+        else:
+            return set()
 
 
 class SynchrotronTyping(object):

synapse/config/server.py

@@ -49,6 +49,9 @@ def read_config(self, config):
         # "disable" federation
         self.send_federation = config.get("send_federation", True)
 
+        # Whether to enable user presence.
+        self.use_presence = config.get("use_presence", True)
+
         # Whether to update the user directory or not. This should be set to
         # false only if we are updating the user directory in a worker
         self.update_user_directory = config.get("update_user_directory", True)
@@ -250,6 +253,9 @@ def default_config(self, server_name, **kwargs):
         # hard limit.
         soft_file_limit: 0
 
+        # Set to false to disable presence tracking on this homeserver.
+        use_presence: true
+
         # The GC threshold parameters to pass to `gc.set_threshold`, if defined
         # gc_thresholds: [700, 10, 10]
 

synapse/federation/transaction_queue.py

@@ -58,6 +58,7 @@ class TransactionQueue(object):
     """
 
     def __init__(self, hs):
+        self.hs = hs
         self.server_name = hs.hostname
 
         self.store = hs.get_datastore()
@@ -308,6 +309,9 @@ def send_presence(self, states):
         Args:
             states (list(UserPresenceState))
         """
+        if not self.hs.config.use_presence:
+            # No-op if presence is disabled.
+            return
 
         # First we queue up the new presence by user ID, so multiple presence
         # updates in quick successtion are correctly handled

synapse/handlers/initial_sync.py

@@ -372,6 +372,10 @@ def _room_initial_sync_joined(self, user_id, room_id, pagin_config,
 
         @defer.inlineCallbacks
         def get_presence():
+            # If presence is disabled, return an empty list
+            if not self.hs.config.use_presence:
+                defer.returnValue([])
+
             states = yield presence_handler.get_states(
                 [m.user_id for m in room_members],
                 as_event=True,

synapse/handlers/presence.py

@@ -395,6 +395,10 @@ def bump_presence_active_time(self, user):
         """We've seen the user do something that indicates they're interacting
         with the app.
         """
+        # If presence is disabled, no-op
+        if not self.hs.config.use_presence:
+            return
+
         user_id = user.to_string()
 
         bump_active_time_counter.inc()
@@ -424,6 +428,11 @@ def user_syncing(self, user_id, affect_presence=True):
                 Useful for streams that are not associated with an actual
                 client that is being used by a user.
         """
+        # Override if it should affect the user's presence, if presence is
+        # disabled.
+        if not self.hs.config.use_presence:
+            affect_presence = False
+
         if affect_presence:
             curr_sync = self.user_to_num_current_syncs.get(user_id, 0)
             self.user_to_num_current_syncs[user_id] = curr_sync + 1
@@ -469,13 +478,16 @@ def get_currently_syncing_users(self):
         Returns:
             set(str): A set of user_id strings.
         """
-        syncing_user_ids = {
-            user_id for user_id, count in self.user_to_num_current_syncs.items()
-            if count
-        }
-        for user_ids in self.external_process_to_current_syncs.values():
-            syncing_user_ids.update(user_ids)
-        return syncing_user_ids
+        if self.hs.config.use_presence:
+            syncing_user_ids = {
+                user_id for user_id, count in self.user_to_num_current_syncs.items()
+                if count
+            }
+            for user_ids in self.external_process_to_current_syncs.values():
+                syncing_user_ids.update(user_ids)
+            return syncing_user_ids
+        else:
+            return set()
 
     @defer.inlineCallbacks
     def update_external_syncs_row(self, process_id, user_id, is_syncing, sync_time_msec):

synapse/handlers/sync.py

@@ -185,6 +185,7 @@ def __nonzero__(self):
 class SyncHandler(object):
 
     def __init__(self, hs):
+        self.hs_config = hs.config
         self.store = hs.get_datastore()
         self.notifier = hs.get_notifier()
         self.presence_handler = hs.get_presence_handler()
@@ -860,7 +861,7 @@ def generate_sync_result(self, sync_config, since_token=None, full_state=False):
             since_token is None and
             sync_config.filter_collection.blocks_all_presence()
         )
-        if not block_all_presence_data:
+        if self.hs_config.use_presence and not block_all_presence_data:
             yield self._generate_sync_entry_for_presence(
                 sync_result_builder, newly_joined_rooms, newly_joined_users
             )