Dedupe KeyedEdu and Devices federation repl traffic

1 files changed, 9 insertions, 6 deletions

diff --git a/synapse/federation/send_queue.py b/synapse/federation/send_queue.py
index 748548bbe2..7d79c069f1 100644
--- a/synapse/federation/send_queue.py
+++ b/synapse/federation/send_queue.py
@@ -267,9 +267,12 @@ class FederationRemoteSendQueue(object):
         keys = self.keyed_edu_changed.keys()
         i = keys.bisect_right(from_token)
         j = keys.bisect_right(to_token) + 1
-        keyed_edus = set((k, self.keyed_edu_changed[k]) for k in keys[i:j])
+        # We purposefully clobber based on the key here, python dict comprehensions
+        # always use the last value, so this will correctly point to the last
+        # stream position.
+        keyed_edus = {self.keyed_edu_changed[k]: k for k in keys[i:j]}
 
-        for (pos, (destination, edu_key)) in keyed_edus:
+        for ((destination, edu_key), pos) in keyed_edus.iteritems():
             rows.append((pos, KeyedEduRow(
                 key=edu_key,
                 edu=self.keyed_edu[(destination, edu_key)],
@@ -279,7 +282,7 @@ class FederationRemoteSendQueue(object):
         keys = self.edus.keys()
         i = keys.bisect_right(from_token)
         j = keys.bisect_right(to_token) + 1
-        edus = set((k, self.edus[k]) for k in keys[i:j])
+        edus = [(k, self.edus[k]) for k in keys[i:j]]
 
         for (pos, edu) in edus:
             rows.append((pos, EduRow(edu)))
@@ -288,7 +291,7 @@ class FederationRemoteSendQueue(object):
         keys = self.failures.keys()
         i = keys.bisect_right(from_token)
         j = keys.bisect_right(to_token) + 1
-        failures = set((k, self.failures[k]) for k in keys[i:j])
+        failures = [(k, self.failures[k]) for k in keys[i:j]]
 
         for (pos, (destination, failure)) in failures:
             rows.append((pos, FailureRow(
@@ -300,9 +303,9 @@ class FederationRemoteSendQueue(object):
         keys = self.device_messages.keys()
         i = keys.bisect_right(from_token)
         j = keys.bisect_right(to_token) + 1
-        device_messages = set((k, self.device_messages[k]) for k in keys[i:j])
+        device_messages = {self.device_messages[k]: k for k in keys[i:j]}
 
-        for (pos, destination) in device_messages:
+        for (destination, pos) in device_messages.iteritems():
             rows.append((pos, DeviceRow(
                 destination=destination,
             )))