Add Stopwatch class, write build times to $cache_prefix.meta.

The Stopwatch class does not have unit tests yet and the build times
stored in the cache for system images may be a little too fine-grained
at the moment.

1 files changed, 48 insertions, 0 deletions

diff --git a/morphlib/stopwatch.py b/morphlib/stopwatch.py
new file mode 100644
index 00000000..5fb4c42d
--- /dev/null
+++ b/morphlib/stopwatch.py
@@ -0,0 +1,48 @@
+# Copyright (C) 2011  Codethink Limited
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+from datetime import datetime
+
+
+class Stopwatch(object):
+
+    def __init__(self):
+        self.ticks = {}
+
+    def tick(self, reference_object, name):
+        if not self.ticks.has_key(reference_object):
+            self.ticks[reference_object] = {}
+        self.ticks[reference_object][name] = datetime.now()
+
+    def enter(self, reference_object):
+        # TODO raise error if start already exists
+        self.tick(reference_object, 'start')
+
+    def leave(self, reference_object):
+        # TODO raise error if stop already exists
+        self.tick(reference_object, 'stop')
+
+    def time(self, reference_object, name):
+        return self.ticks[reference_object][name]
+
+    def start(self, reference_object):
+        return self.ticks[reference_object]['start']
+
+    def stop(self, reference_object):
+        return self.ticks[reference_object]['stop']
+
+    def delta(self, reference_object):
+        return self.stop(reference_object) - self.start(reference_object)