Add new attribute class. Realy...

glances/attribute.py

+# -*- coding: utf-8 -*-
+#
+# This file is part of Glances.
+#
+# Copyright (C) 2015 Nicolargo <nicolas@nicolargo.com>
+#
+# Glances is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Glances 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+"""Attribute class."""
+
+from time import time
+
+
+class GlancesAttribute(object):
+
+    def __init__(self, name, description='', history_max_size=None, is_rate=False):
+        """Init the attribute
+        name: Attribute name (string)
+        description: Attribute human reading description (string)
+        history_max_size: Maximum size of the history list (default is no limit)
+        is_rate: If True then the value is manage like a rate (store timestamp in the history)
+        """
+        self._name = name
+        self._description = description
+        self._value = None
+        self._history_max_size = history_max_size
+        self._history = []
+        self.is_rate = is_rate
+
+    def __repr__(self):
+        return self.value
+
+    def __str__(self):
+        return str(self.value)
+
+    """
+    Properties for the attribute name
+    """
+    @property
+    def name(self):
+        return self._name
+
+    @name.setter
+    def name(self, new_name):
+        self._name = new_name
+
+    """
+    Properties for the attribute description
+    """
+    @property
+    def description(self):
+        return self._description
+
+    @description.setter
+    def description(self, new_description):
+        self._description = new_description
+
+    """
+    Properties for the attribute value
+    """
+    @property
+    def value(self):
+        if self.is_rate:
+            if self.history_len() > 0:
+                return (self._value[1] - self.history_value()[1]) / (self._value[0] - self.history_value()[0])
+            else:
+                return None
+        else:
+            return self._value
+
+    @value.setter
+    def value(self, new_value):
+        """Set a value.
+        If self.is_rate is True, store a tuple with (<timestamp>, value)
+        else, store directly the value (wathever type is it)
+        """
+        if self.is_rate:
+            new_value = (time(), new_value)
+        if self._value is not None:
+            self.history_add(self._value)
+        self._value = new_value
+
+    """
+    Properties for the attribute history
+    """
+    @property
+    def history(self):
+        return self._history
+
+    @history.setter
+    def history(self, new_history):
+        self._history = new_history
+
+    @history.deleter
+    def history(self):
+        del self._history
+
+    def history_reset(self):
+        self._history = []
+
+    def history_add(self, value):
+        """Add a value in the history
+        """
+        if self._history_max_size is None or self.history_len() < self._history_max_size:
+            self._history.append(value)
+        else:
+            self._history = self._history[1:] + [value]
+
+    def history_size(self):
+        """Return the history size (maximum nuber of value in the history)
+        """
+        return len(self._history)
+
+    def history_len(self):
+        """Return the current history lenght
+        """
+        return len(self._history)
+
+    def history_value(self, pos=1):
+        """Return the value in position pos in the history.
+        Default is to return the latest value added to the history.
+        """
+        return self._history[-pos]
+
+    def history_mean(self, nb=5):
+        """Return the mean on the <nb> values in the history.
+        """
+        if self.is_rate:
+            h_sum = map(sum, zip(*self._history[-nb:]))
+            return h_sum[1] / float(self._history[-1][0] - self._history[-nb][0])
+        else:
+            return sum(self._history[-nb:]) / float(nb)