1 files changed, 97 insertions, 0 deletions
diff --git a/synapse/util/metrics.py b/synapse/util/metrics.py
new file mode 100644
index 0000000000..c51b641125
--- /dev/null
+++ b/synapse/util/metrics.py
@@ -0,0 +1,97 @@
+# -*- coding: utf-8 -*-
+# Copyright 2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from synapse.util.logcontext import LoggingContext
+import synapse.metrics
+
+import logging
+
+
+logger = logging.getLogger(__name__)
+
+
+metrics = synapse.metrics.get_metrics_for(__name__)
+
+block_timer = metrics.register_distribution(
+    "block_timer",
+    labels=["block_name"]
+)
+
+block_ru_utime = metrics.register_distribution(
+    "block_ru_utime", labels=["block_name"]
+)
+
+block_ru_stime = metrics.register_distribution(
+    "block_ru_stime", labels=["block_name"]
+)
+
+block_db_txn_count = metrics.register_distribution(
+    "block_db_txn_count", labels=["block_name"]
+)
+
+block_db_txn_duration = metrics.register_distribution(
+    "block_db_txn_duration", labels=["block_name"]
+)
+
+
+class Measure(object):
+    __slots__ = [
+        "clock", "name", "start_context", "start", "new_context", "ru_utime",
+        "ru_stime", "db_txn_count", "db_txn_duration"
+    ]
+
+    def __init__(self, clock, name):
+        self.clock = clock
+        self.name = name
+        self.start_context = None
+        self.start = None
+
+    def __enter__(self):
+        self.start = self.clock.time_msec()
+        self.start_context = LoggingContext.current_context()
+        if self.start_context:
+            self.ru_utime, self.ru_stime = self.start_context.get_resource_usage()
+            self.db_txn_count = self.start_context.db_txn_count
+            self.db_txn_duration = self.start_context.db_txn_duration
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if exc_type is not None or not self.start_context:
+            return
+
+        duration = self.clock.time_msec() - self.start
+        block_timer.inc_by(duration, self.name)
+
+        context = LoggingContext.current_context()
+
+        if context != self.start_context:
+            logger.warn(
+                "Context have unexpectedly changed from '%s' to '%s'. (%r)",
+                context, self.start_context, self.name
+            )
+            return
+
+        if not context:
+            logger.warn("Expected context. (%r)", self.name)
+            return
+
+        ru_utime, ru_stime = context.get_resource_usage()
+
+        block_ru_utime.inc_by(ru_utime - self.ru_utime, self.name)
+        block_ru_stime.inc_by(ru_stime - self.ru_stime, self.name)
+        block_db_txn_count.inc_by(context.db_txn_count - self.db_txn_count, self.name)
+        block_db_txn_duration.inc_by(
+            context.db_txn_duration - self.db_txn_duration, self.name
+        )