Merge pull request #2976 from matrix-org/erikj/replication_registry

Split out edu/query registration to a separate class

1 files changed, 69 insertions, 48 deletions

diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 9849953c9b..90302c9537 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -17,7 +17,7 @@ import logging
 import simplejson as json
 from twisted.internet import defer
 
-from synapse.api.errors import AuthError, FederationError, SynapseError
+from synapse.api.errors import AuthError, FederationError, SynapseError, NotFoundError
 from synapse.crypto.event_signing import compute_event_signature
 from synapse.federation.federation_base import (
     FederationBase,
@@ -56,6 +56,8 @@ class FederationServer(FederationBase):
         self._server_linearizer = async.Linearizer("fed_server")
         self._transaction_linearizer = async.Linearizer("fed_txn_handler")
 
+        self.registry = hs.get_federation_registry()
+
         # We cache responses to state queries, as they take a while and often
         # come in waves.
         self._state_resp_cache = ResponseCache(hs, timeout_ms=30000)
@@ -67,35 +69,6 @@ class FederationServer(FederationBase):
         """
         self.handler = handler
 
-    def register_edu_handler(self, edu_type, handler):
-        if edu_type in self.edu_handlers:
-            raise KeyError("Already have an EDU handler for %s" % (edu_type,))
-
-        self.edu_handlers[edu_type] = handler
-
-    def register_query_handler(self, query_type, handler):
-        """Sets the handler callable that will be used to handle an incoming
-        federation Query of the given type.
-
-        Args:
-            query_type (str): Category name of the query, which should match
-                the string used by make_query.
-            handler (callable): Invoked to handle incoming queries of this type
-
-        handler is invoked as:
-            result = handler(args)
-
-        where 'args' is a dict mapping strings to strings of the query
-          arguments. It should return a Deferred that will eventually yield an
-          object to encode as JSON.
-        """
-        if query_type in self.query_handlers:
-            raise KeyError(
-                "Already have a Query handler for %s" % (query_type,)
-            )
-
-        self.query_handlers[query_type] = handler
-
     @defer.inlineCallbacks
     @log_function
     def on_backfill_request(self, origin, room_id, versions, limit):
@@ -229,16 +202,7 @@ class FederationServer(FederationBase):
     @defer.inlineCallbacks
     def received_edu(self, origin, edu_type, content):
         received_edus_counter.inc()
-
-        if edu_type in self.edu_handlers:
-            try:
-                yield self.edu_handlers[edu_type](origin, content)
-            except SynapseError as e:
-                logger.info("Failed to handle edu %r: %r", edu_type, e)
-            except Exception as e:
-                logger.exception("Failed to handle edu %r", edu_type)
-        else:
-            logger.warn("Received EDU of type %s with no handler", edu_type)
+        yield self.registry.on_edu(edu_type, origin, content)
 
     @defer.inlineCallbacks
     @log_function
@@ -328,14 +292,8 @@ class FederationServer(FederationBase):
     @defer.inlineCallbacks
     def on_query_request(self, query_type, args):
         received_queries_counter.inc(query_type)
-
-        if query_type in self.query_handlers:
-            response = yield self.query_handlers[query_type](args)
-            defer.returnValue((200, response))
-        else:
-            defer.returnValue(
-                (404, "No handler for Query type '%s'" % (query_type,))
-            )
+        resp = yield self.registry.on_query(query_type, args)
+        defer.returnValue((200, resp))
 
     @defer.inlineCallbacks
     def on_make_join_request(self, room_id, user_id):
@@ -607,3 +565,66 @@ class FederationServer(FederationBase):
             origin, room_id, event_dict
         )
         defer.returnValue(ret)
+
+
+class FederationHandlerRegistry(object):
+    """Allows classes to register themselves as handlers for a given EDU or
+    query type for incoming federation traffic.
+    """
+    def __init__(self):
+        self.edu_handlers = {}
+        self.query_handlers = {}
+
+    def register_edu_handler(self, edu_type, handler):
+        """Sets the handler callable that will be used to handle an incoming
+        federation EDU of the given type.
+
+        Args:
+            edu_type (str): The type of the incoming EDU to register handler for
+            handler (Callable[[str, dict]]): A callable invoked on incoming EDU
+                of the given type. The arguments are the origin server name and
+                the EDU contents.
+        """
+        if edu_type in self.edu_handlers:
+            raise KeyError("Already have an EDU handler for %s" % (edu_type,))
+
+        self.edu_handlers[edu_type] = handler
+
+    def register_query_handler(self, query_type, handler):
+        """Sets the handler callable that will be used to handle an incoming
+        federation query of the given type.
+
+        Args:
+            query_type (str): Category name of the query, which should match
+                the string used by make_query.
+            handler (Callable[[dict], Deferred[dict]]): Invoked to handle
+                incoming queries of this type. The return will be yielded
+                on and the result used as the response to the query request.
+        """
+        if query_type in self.query_handlers:
+            raise KeyError(
+                "Already have a Query handler for %s" % (query_type,)
+            )
+
+        self.query_handlers[query_type] = handler
+
+    @defer.inlineCallbacks
+    def on_edu(self, edu_type, origin, content):
+        handler = self.edu_handlers.get(edu_type)
+        if not handler:
+            logger.warn("No handler registered for EDU type %s", edu_type)
+
+        try:
+            yield handler(origin, content)
+        except SynapseError as e:
+            logger.info("Failed to handle edu %r: %r", edu_type, e)
+        except Exception as e:
+            logger.exception("Failed to handle edu %r", edu_type)
+
+    def on_query(self, query_type, args):
+        handler = self.query_handlers.get(query_type)
+        if not handler:
+            logger.warn("No handler registered for query type %s", query_type)
+            raise NotFoundError("No handler for Query type '%s'" % (query_type,))
+
+        return handler(args)