1 files changed, 92 insertions, 0 deletions
diff --git a/src/leap/bitmask/util/averages.py b/src/leap/bitmask/util/averages.py
new file mode 100644
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+++ b/src/leap/bitmask/util/averages.py
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+# -*- coding: utf-8 -*-
+# averages.py
+# Copyright (C) 2013 LEAP
+#
+# 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/>.
+"""
+Utility class for moving averages.
+
+It is used in the status panel widget for displaying up and down
+download rates.
+"""
+from leap.bitmask.util import first
+
+
+class RateMovingAverage(object):
+    """
+    Moving window average for calculating
+    upload and download rates.
+    """
+    SAMPLE_SIZE = 5
+
+    def __init__(self):
+        """
+        Initializes an empty array of fixed size
+        """
+        self.reset()
+
+    def reset(self):
+        self._data = [None for i in xrange(self.SAMPLE_SIZE)]
+
+    def append(self, x):
+        """
+        Appends a new data point to the collection.
+
+        :param x: A tuple containing timestamp and traffic points
+                  in the form (timestamp, traffic)
+        :type x: tuple
+        """
+        self._data.pop(0)
+        self._data.append(x)
+
+    def get(self):
+        """
+        Gets the collection.
+        """
+        return self._data
+
+    def get_average(self):
+        """
+        Gets the moving average.
+        """
+        data = filter(None, self.get())
+        traff = [traffic for (ts, traffic) in data]
+        times = [ts for (ts, traffic) in data]
+
+        try:
+            deltatraffic = traff[-1] - first(traff)
+            deltat = (times[-1] - first(times)).seconds
+        except IndexError:
+            deltatraffic = 0
+            deltat = 0
+
+        try:
+            rate = float(deltatraffic) / float(deltat) / 1024
+        except ZeroDivisionError:
+            rate = 0
+
+        # In some cases we get negative rates
+        if rate < 0:
+            rate = 0
+
+        return rate
+
+    def get_total(self):
+        """
+        Gets the total accumulated throughput.
+        """
+        try:
+            return self._data[-1][1] / 1024
+        except TypeError:
+            return 0