Merge tag 'v1.39.0rc3'

Synapse 1.39.0rc3 (2021-07-28)
==============================

Bugfixes
--------

- Fix a bug introduced in Synapse 1.38 which caused an exception at startup when SAML authentication was enabled. ([\#10477](https://github.com/matrix-org/synapse/issues/10477))
- Fix a long-standing bug where Synapse would not inform clients that a device had exhausted its one-time-key pool, potentially causing problems decrypting events. ([\#10485](https://github.com/matrix-org/synapse/issues/10485))
- Fix reporting old R30 stats as R30v2 stats. Introduced in v1.39.0rc1. ([\#10486](https://github.com/matrix-org/synapse/issues/10486))

Internal Changes
----------------

- Fix an error which prevented the Github Actions workflow to build the docker images from running. ([\#10461](https://github.com/matrix-org/synapse/issues/10461))
- Fix release script to correctly version debian changelog when doing RCs. ([\#10465](https://github.com/matrix-org/synapse/issues/10465))

3 files changed, 19 insertions, 22 deletions

diff --git a/synapse/metrics/__init__.py b/synapse/metrics/__init__.py
index fef2846669..f237b8a236 100644
--- a/synapse/metrics/__init__.py
+++ b/synapse/metrics/__init__.py
@@ -46,7 +46,7 @@ logger = logging.getLogger(__name__)
 METRICS_PREFIX = "/_synapse/metrics"
 
 running_on_pypy = platform.python_implementation() == "PyPy"
-all_gauges = {}  # type: Dict[str, Union[LaterGauge, InFlightGauge]]
+all_gauges: "Dict[str, Union[LaterGauge, InFlightGauge]]" = {}
 
 HAVE_PROC_SELF_STAT = os.path.exists("/proc/self/stat")
 
@@ -130,7 +130,7 @@ class InFlightGauge:
         )
 
         # Counts number of in flight blocks for a given set of label values
-        self._registrations = {}  # type: Dict
+        self._registrations: Dict = {}
 
         # Protects access to _registrations
         self._lock = threading.Lock()
@@ -248,7 +248,7 @@ class GaugeBucketCollector:
 
         # We initially set this to None. We won't report metrics until
         # this has been initialised after a successful data update
-        self._metric = None  # type: Optional[GaugeHistogramMetricFamily]
+        self._metric: Optional[GaugeHistogramMetricFamily] = None
 
         registry.register(self)
 
diff --git a/synapse/metrics/_exposition.py b/synapse/metrics/_exposition.py
index 8002be56e0..bb9bcb5592 100644
--- a/synapse/metrics/_exposition.py
+++ b/synapse/metrics/_exposition.py
@@ -34,7 +34,7 @@ from twisted.web.resource import Resource
 
 from synapse.util import caches
 
-CONTENT_TYPE_LATEST = str("text/plain; version=0.0.4; charset=utf-8")
+CONTENT_TYPE_LATEST = "text/plain; version=0.0.4; charset=utf-8"
 
 
 INF = float("inf")
@@ -55,8 +55,8 @@ def floatToGoString(d):
         # Go switches to exponents sooner than Python.
         # We only need to care about positive values for le/quantile.
         if d > 0 and dot > 6:
-            mantissa = "{0}.{1}{2}".format(s[0], s[1:dot], s[dot + 1 :]).rstrip("0.")
-            return "{0}e+0{1}".format(mantissa, dot - 1)
+            mantissa = f"{s[0]}.{s[1:dot]}{s[dot + 1 :]}".rstrip("0.")
+            return f"{mantissa}e+0{dot - 1}"
         return s
 
 
@@ -65,7 +65,7 @@ def sample_line(line, name):
         labelstr = "{{{0}}}".format(
             ",".join(
                 [
-                    '{0}="{1}"'.format(
+                    '{}="{}"'.format(
                         k,
                         v.replace("\\", r"\\").replace("\n", r"\n").replace('"', r"\""),
                     )
@@ -78,10 +78,8 @@ def sample_line(line, name):
     timestamp = ""
     if line.timestamp is not None:
         # Convert to milliseconds.
-        timestamp = " {0:d}".format(int(float(line.timestamp) * 1000))
-    return "{0}{1} {2}{3}\n".format(
-        name, labelstr, floatToGoString(line.value), timestamp
-    )
+        timestamp = f" {int(float(line.timestamp) * 1000):d}"
+    return "{}{} {}{}\n".format(name, labelstr, floatToGoString(line.value), timestamp)
 
 
 def generate_latest(registry, emit_help=False):
@@ -118,14 +116,14 @@ def generate_latest(registry, emit_help=False):
         # Output in the old format for compatibility.
         if emit_help:
             output.append(
-                "# HELP {0} {1}\n".format(
+                "# HELP {} {}\n".format(
                     mname,
                     metric.documentation.replace("\\", r"\\").replace("\n", r"\n"),
                 )
             )
-        output.append("# TYPE {0} {1}\n".format(mname, mtype))
+        output.append(f"# TYPE {mname} {mtype}\n")
 
-        om_samples = {}  # type: Dict[str, List[str]]
+        om_samples: Dict[str, List[str]] = {}
         for s in metric.samples:
             for suffix in ["_created", "_gsum", "_gcount"]:
                 if s.name == metric.name + suffix:
@@ -143,13 +141,13 @@ def generate_latest(registry, emit_help=False):
         for suffix, lines in sorted(om_samples.items()):
             if emit_help:
                 output.append(
-                    "# HELP {0}{1} {2}\n".format(
+                    "# HELP {}{} {}\n".format(
                         metric.name,
                         suffix,
                         metric.documentation.replace("\\", r"\\").replace("\n", r"\n"),
                     )
                 )
-            output.append("# TYPE {0}{1} gauge\n".format(metric.name, suffix))
+            output.append(f"# TYPE {metric.name}{suffix} gauge\n")
             output.extend(lines)
 
         # Get rid of the weird colon things while we're at it
@@ -163,12 +161,12 @@ def generate_latest(registry, emit_help=False):
         # Also output in the new format, if it's different.
         if emit_help:
             output.append(
-                "# HELP {0} {1}\n".format(
+                "# HELP {} {}\n".format(
                     mnewname,
                     metric.documentation.replace("\\", r"\\").replace("\n", r"\n"),
                 )
             )
-        output.append("# TYPE {0} {1}\n".format(mnewname, mtype))
+        output.append(f"# TYPE {mnewname} {mtype}\n")
 
         for s in metric.samples:
             # Get rid of the OpenMetrics specific samples (we should already have
diff --git a/synapse/metrics/background_process_metrics.py b/synapse/metrics/background_process_metrics.py
index de96ca0821..3a14260752 100644
--- a/synapse/metrics/background_process_metrics.py
+++ b/synapse/metrics/background_process_metrics.py
@@ -93,7 +93,7 @@ _background_process_db_sched_duration = Counter(
 # map from description to a counter, so that we can name our logcontexts
 # incrementally. (It actually duplicates _background_process_start_count, but
 # it's much simpler to do so than to try to combine them.)
-_background_process_counts = {}  # type: Dict[str, int]
+_background_process_counts: Dict[str, int] = {}
 
 # Set of all running background processes that became active active since the
 # last time metrics were scraped (i.e. background processes that performed some
@@ -103,7 +103,7 @@ _background_process_counts = {}  # type: Dict[str, int]
 # background processes stacking up behind a lock or linearizer, where we then
 # only need to iterate over and update metrics for the process that have
 # actually been active and can ignore the idle ones.
-_background_processes_active_since_last_scrape = set()  # type: Set[_BackgroundProcess]
+_background_processes_active_since_last_scrape: "Set[_BackgroundProcess]" = set()
 
 # A lock that covers the above set and dict
 _bg_metrics_lock = threading.Lock()
@@ -137,8 +137,7 @@ class _Collector:
             _background_process_db_txn_duration,
             _background_process_db_sched_duration,
         ):
-            for r in m.collect():
-                yield r
+            yield from m.collect()
 
 
 REGISTRY.register(_Collector())