Remove obsolete order field in send_new_transaction (#8245)

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

synapse/federation/sender/transaction_manager.py

@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import TYPE_CHECKING, List, Tuple
+from typing import TYPE_CHECKING, List
 
 from synapse.api.errors import HttpResponseException
 from synapse.events import EventBase
@@ -53,11 +53,17 @@ class TransactionManager(object):
 
     @measure_func("_send_new_transaction")
     async def send_new_transaction(
-        self,
-        destination: str,
-        pending_pdus: List[Tuple[EventBase, int]],
-        pending_edus: List[Edu],
-    ):
+        self, destination: str, pdus: List[EventBase], edus: List[Edu],
+    ) -> bool:
+        """
+        Args:
+            destination: The destination to send to (e.g. 'example.org')
+            pdus: In-order list of PDUs to send
+            edus: List of EDUs to send
+
+        Returns:
+            True iff the transaction was successful
+        """
 
         # Make a transaction-sending opentracing span. This span follows on from
         # all the edus in that transaction. This needs to be done since there is
@@ -67,7 +73,7 @@ class TransactionManager(object):
         span_contexts = []
         keep_destination = whitelisted_homeserver(destination)
 
-        for edu in pending_edus:
+        for edu in edus:
             context = edu.get_context()
             if context:
                 span_contexts.append(extract_text_map(json_decoder.decode(context)))
@@ -75,12 +81,6 @@ class TransactionManager(object):
                 edu.strip_context()
 
         with start_active_span_follows_from("send_transaction", span_contexts):
-
-            # Sort based on the order field
-            pending_pdus.sort(key=lambda t: t[1])
-            pdus = [x[0] for x in pending_pdus]
-            edus = pending_edus
-
             success = True
 
             logger.debug("TX [%s] _attempt_new_transaction", destination)