1 files changed, 61 insertions, 0 deletions
diff --git a/ttystatus/speed.py b/ttystatus/speed.py
new file mode 100644
index 0000000..2a1221a
--- /dev/null
+++ b/ttystatus/speed.py
@@ -0,0 +1,61 @@
+# Copyright 2010, 2012  Lars Wirzenius
+#
+# 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, either version 3 of the License, or
+# (at your option) any later version.
+#
+# 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, see <http://www.gnu.org/licenses/>.
+
+
+import time
+
+import ttystatus
+
+
+class Speed(ttystatus.Widget):
+
+    '''Display speed of changes.'''
+
+    static_width = False
+
+    def __init__(self, name, duration=None):
+        self.name = name
+        self._duration = None if duration is None else float(duration)
+        self._data_points = []
+        self._changes = 0
+
+    def now(self):  # pragma: no cover
+        '''Wrapper around time.time for unit tests to overrride.'''
+        return time.time()
+
+    def render(self, width):
+        if len(self._data_points) < 2:
+            speed = 0.0
+        else:  # pragma: no cover
+            oldest, started = self._data_points[0]
+            latest, _ = self._data_points[-1]
+            delta = latest - oldest
+            now = self.now()
+            duration = now - started
+            speed = float(delta) / float(duration)
+
+        return '%.2f/s' % float(speed)
+
+    def update(self, master):  # pragma: no cover
+        self._changes += 1
+        now = self.now()
+        self._data_points.append((self._changes, now))
+        if self._duration is None:
+            if len(self._data_points) > 2:
+                del self._data_points[1:-1]
+        else:
+            cutoff = now - self._duration
+            while self._data_points[0][1] < cutoff:
+                del self._data_points[0]