Merge: Adds a module for logging requests

Title pretty much says it all

Pull-Request: #1869
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>

lib/nitcorn/log.nit

@@ -0,0 +1,59 @@
+# This file is part of NIT ( http://www.nitlanguage.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.
+
+# Services inserting a timestamp in all prints and to log each requests
+# Also keep track of the performances of the requests
+module log
+
+import reactor
+import realtime
+import performance_analysis
+
+redef class Action
+
+	redef fun prepare_respond_and_close(request, truncated_uri, http_server) do
+		if not log_nitcorn_actions then
+			super
+			return
+		end
+		print """{{{class_name}}} enter:
+uri="{{{truncated_uri}}}"
+query="{{{request.query_string}}}"
+body:{{{request.body.length}}} bytes"""
+		var clock = new Clock
+		super
+		var perf = sys.perfs[class_name]
+		perf.add(clock.lapse)
+		if perf.count % perfs_print_period == 0 then print "{class_name} perfs: {perf}:"
+		print "{class_name} return: uri={truncated_uri}"
+	end
+end
+
+redef fun print(object) do
+	var timestamp = new Tm.gmtime
+	super "{timestamp.year}/{timestamp.mon}/{timestamp.mday} "+
+	"{timestamp.hour}:{timestamp.min}:{timestamp.sec}: {object}"
+end
+
+redef fun print_error(object) do
+	var timestamp = new Tm.gmtime
+	super "{timestamp.year}/{timestamp.mon}/{timestamp.mday} "+
+	"{timestamp.hour}:{timestamp.min}:{timestamp.sec}: {object}"
+end
+
+# Should the actions be logged ?
+fun log_nitcorn_actions: Bool do return false
+
+# Number of actions executed before printing the perfs
+fun perfs_print_period: Int do return 20