1 files changed, 65 insertions, 0 deletions
diff --git a/synapse/util/logutils.py b/synapse/util/logutils.py
new file mode 100644
index 0000000000..08d5aafca4
--- /dev/null
+++ b/synapse/util/logutils.py
@@ -0,0 +1,65 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014 matrix.org
+#
+# 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 inspect import getcallargs
+
+import logging
+
+
+def log_function(f):
+    """ Function decorator that logs every call to that function.
+    """
+    func_name = f.__name__
+    lineno = f.func_code.co_firstlineno
+    pathname = f.func_code.co_filename
+
+    def wrapped(*args, **kwargs):
+        name = f.__module__
+        logger = logging.getLogger(name)
+        level = logging.DEBUG
+
+        if logger.isEnabledFor(level):
+            bound_args = getcallargs(f, *args, **kwargs)
+
+            def format(value):
+                r = str(value)
+                if len(r) > 50:
+                    r = r[:50] + "..."
+                return r
+
+            func_args = [
+                "%s=%s" % (k, format(v)) for k, v in bound_args.items()
+            ]
+
+            msg_args = {
+                "func_name": func_name,
+                "args": ", ".join(func_args)
+            }
+
+            record = logging.LogRecord(
+                name=name,
+                level=level,
+                pathname=pathname,
+                lineno=lineno,
+                msg="Invoked '%(func_name)s' with args: %(args)s",
+                args=msg_args,
+                exc_info=None
+            )
+
+            logger.handle(record)
+
+        return f(*args, **kwargs)
+
+    return wrapped