Merge branch 'release-v0.17.0' of github.com:matrix-org/synapse v0.17.0

6 files changed, 107 insertions, 10 deletions

diff --git a/synapse/util/async.py b/synapse/util/async.py
index 40be7fe7e3..c84b23ff46 100644
--- a/synapse/util/async.py
+++ b/synapse/util/async.py
@@ -194,3 +194,85 @@ class Linearizer(object):
                     self.key_to_defer.pop(key, None)
 
         defer.returnValue(_ctx_manager())
+
+
+class ReadWriteLock(object):
+    """A deferred style read write lock.
+
+    Example:
+
+        with (yield read_write_lock.read("test_key")):
+            # do some work
+    """
+
+    # IMPLEMENTATION NOTES
+    #
+    # We track the most recent queued reader and writer deferreds (which get
+    # resolved when they release the lock).
+    #
+    # Read: We know its safe to acquire a read lock when the latest writer has
+    # been resolved. The new reader is appeneded to the list of latest readers.
+    #
+    # Write: We know its safe to acquire the write lock when both the latest
+    # writers and readers have been resolved. The new writer replaces the latest
+    # writer.
+
+    def __init__(self):
+        # Latest readers queued
+        self.key_to_current_readers = {}
+
+        # Latest writer queued
+        self.key_to_current_writer = {}
+
+    @defer.inlineCallbacks
+    def read(self, key):
+        new_defer = defer.Deferred()
+
+        curr_readers = self.key_to_current_readers.setdefault(key, set())
+        curr_writer = self.key_to_current_writer.get(key, None)
+
+        curr_readers.add(new_defer)
+
+        # We wait for the latest writer to finish writing. We can safely ignore
+        # any existing readers... as they're readers.
+        yield curr_writer
+
+        @contextmanager
+        def _ctx_manager():
+            try:
+                yield
+            finally:
+                new_defer.callback(None)
+                self.key_to_current_readers.get(key, set()).discard(new_defer)
+
+        defer.returnValue(_ctx_manager())
+
+    @defer.inlineCallbacks
+    def write(self, key):
+        new_defer = defer.Deferred()
+
+        curr_readers = self.key_to_current_readers.get(key, set())
+        curr_writer = self.key_to_current_writer.get(key, None)
+
+        # We wait on all latest readers and writer.
+        to_wait_on = list(curr_readers)
+        if curr_writer:
+            to_wait_on.append(curr_writer)
+
+        # We can clear the list of current readers since the new writer waits
+        # for them to finish.
+        curr_readers.clear()
+        self.key_to_current_writer[key] = new_defer
+
+        yield defer.gatherResults(to_wait_on)
+
+        @contextmanager
+        def _ctx_manager():
+            try:
+                yield
+            finally:
+                new_defer.callback(None)
+                if self.key_to_current_writer[key] == new_defer:
+                    self.key_to_current_writer.pop(key)
+
+        defer.returnValue(_ctx_manager())
diff --git a/synapse/util/caches/response_cache.py b/synapse/util/caches/response_cache.py
index 36686b479e..00af539880 100644
--- a/synapse/util/caches/response_cache.py
+++ b/synapse/util/caches/response_cache.py
@@ -24,9 +24,12 @@ class ResponseCache(object):
     used rather than trying to compute a new response.
     """
 
-    def __init__(self):
+    def __init__(self, hs, timeout_ms=0):
         self.pending_result_cache = {}  # Requests that haven't finished yet.
 
+        self.clock = hs.get_clock()
+        self.timeout_sec = timeout_ms / 1000.
+
     def get(self, key):
         result = self.pending_result_cache.get(key)
         if result is not None:
@@ -39,7 +42,13 @@ class ResponseCache(object):
         self.pending_result_cache[key] = result
 
         def remove(r):
-            self.pending_result_cache.pop(key, None)
+            if self.timeout_sec:
+                self.clock.call_later(
+                    self.timeout_sec,
+                    self.pending_result_cache.pop, key, None,
+                )
+            else:
+                self.pending_result_cache.pop(key, None)
             return r
 
         result.addBoth(remove)
diff --git a/synapse/util/metrics.py b/synapse/util/metrics.py
index e1f374807e..0b944d3e63 100644
--- a/synapse/util/metrics.py
+++ b/synapse/util/metrics.py
@@ -84,7 +84,7 @@ class Measure(object):
 
         if context != self.start_context:
             logger.warn(
-                "Context have unexpectedly changed from '%s' to '%s'. (%r)",
+                "Context has unexpectedly changed from '%s' to '%s'. (%r)",
                 context, self.start_context, self.name
             )
             return
diff --git a/synapse/util/presentable_names.py b/synapse/util/presentable_names.py
index a6866f6117..f68676e9e7 100644
--- a/synapse/util/presentable_names.py
+++ b/synapse/util/presentable_names.py
@@ -25,7 +25,8 @@ ALIAS_RE = re.compile(r"^#.*:.+$")
 ALL_ALONE = "Empty Room"
 
 
-def calculate_room_name(room_state, user_id, fallback_to_members=True):
+def calculate_room_name(room_state, user_id, fallback_to_members=True,
+                        fallback_to_single_member=True):
     """
     Works out a user-facing name for the given room as per Matrix
     spec recommendations.
@@ -82,7 +83,10 @@ def calculate_room_name(room_state, user_id, fallback_to_members=True):
     ):
         if ("m.room.member", my_member_event.sender) in room_state:
             inviter_member_event = room_state[("m.room.member", my_member_event.sender)]
-            return "Invite from %s" % (name_from_member_event(inviter_member_event),)
+            if fallback_to_single_member:
+                return "Invite from %s" % (name_from_member_event(inviter_member_event),)
+            else:
+                return None
         else:
             return "Room Invite"
 
@@ -129,6 +133,8 @@ def calculate_room_name(room_state, user_id, fallback_to_members=True):
                 return name_from_member_event(all_members[0])
         else:
             return ALL_ALONE
+    elif len(other_members) == 1 and not fallback_to_single_member:
+        return None
     else:
         return descriptor_from_member_events(other_members)
 
diff --git a/synapse/util/retryutils.py b/synapse/util/retryutils.py
index 43cf11f3f6..49527f4d21 100644
--- a/synapse/util/retryutils.py
+++ b/synapse/util/retryutils.py
@@ -128,7 +128,7 @@ class RetryDestinationLimiter(object):
             )
 
         valid_err_code = False
-        if exc_type is CodeMessageException:
+        if exc_type is not None and issubclass(exc_type, CodeMessageException):
             valid_err_code = 0 <= exc_val.code < 500
 
         if exc_type is None or valid_err_code:
diff --git a/synapse/util/versionstring.py b/synapse/util/versionstring.py
index a4f156cb3b..52086df465 100644
--- a/synapse/util/versionstring.py
+++ b/synapse/util/versionstring.py
@@ -21,7 +21,7 @@ import logging
 logger = logging.getLogger(__name__)
 
 
-def get_version_string(name, module):
+def get_version_string(module):
     try:
         null = open(os.devnull, 'w')
         cwd = os.path.dirname(os.path.abspath(module.__file__))
@@ -74,11 +74,11 @@ def get_version_string(name, module):
             )
 
             return (
-                "%s/%s (%s)" % (
-                    name, module.__version__, git_version,
+                "%s (%s)" % (
+                    module.__version__, git_version,
                 )
             ).encode("ascii")
     except Exception as e:
         logger.info("Failed to check for git repository: %s", e)
 
-    return ("%s/%s" % (name, module.__version__,)).encode("ascii")
+    return module.__version__.encode("ascii")