From b951f35572119749eee0160b70b5b76382223103 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 28 Nov 2018 20:09:39 +0000
Subject: [PATCH] Reduce size of fed transaction IDs

---
 synapse/federation/transaction_queue.py | 21 +++++++++++++++++++--
 synapse/http/endpoint.py                |  7 +++++--
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/synapse/federation/transaction_queue.py b/synapse/federation/transaction_queue.py
index ba3b3fd2f9..00bbf01620 100644
--- a/synapse/federation/transaction_queue.py
+++ b/synapse/federation/transaction_queue.py
@@ -17,6 +17,7 @@ import logging
 import random
 import json
 import opentracing
+import string
 
 from six import itervalues
 
@@ -135,7 +136,7 @@ class TransactionQueue(object):
         self.last_device_list_stream_id_by_dest = {}
 
         # HACK to get unique tx id
-        self._next_txn_id = int(self.clock.time_msec())
+        self._next_txn_id = 1
 
         self._order = 1
 
@@ -486,7 +487,7 @@ class TransactionQueue(object):
 
             pending_pdus = []
             while True:
-                txn_id = str(self._next_txn_id)
+                txn_id = _encode_id(self._next_txn_id)
                 self._next_txn_id += 1
 
                 for s in pdu_spans.values():
@@ -860,3 +861,19 @@ class TransactionQueue(object):
         new_destinations = set(pdu.unsigned.get("destinations", []))
         new_destinations.discard(destination)
         yield self._send_pdu(pdu, list(new_destinations), span)
+
+
+def _numberToBase(n, b):
+    if n == 0:
+        return [0]
+    digits = []
+    while n:
+        digits.append(int(n % b))
+        n //= b
+    return digits[::-1]
+
+
+def _encode_id(i):
+    digits = string.digits + string.ascii_letters
+    val_slice = _numberToBase(i, len(digits))
+    return "".join(digits[x] for x in val_slice)
diff --git a/synapse/http/endpoint.py b/synapse/http/endpoint.py
index 91025037a3..df528113a4 100644
--- a/synapse/http/endpoint.py
+++ b/synapse/http/endpoint.py
@@ -194,8 +194,11 @@ class _WrappedConnection(object):
             # In Twisted >18.4; the TLS connection will be None if it has closed
             # which will make abortConnection() throw. Check that the TLS connection
             # is not None before trying to close it.
-            if self.transport.getHandle() is not None:
-                self.transport.abortConnection()
+            try:
+                if self.transport.getHandle() is not None:
+                    self.transport.abortConnection()
+            except:
+                logger.warning("Failed to abort connection")
 
     def request(self, request):
         self.last_request = time.time()