Add trends in the Curses interface #1077

NEWS

@@ -8,6 +8,7 @@ Version 2.9.2
 Enhancements and new features:
 
     * Use -> and <- arrows keys to switch between processing sort (issue #1075)
+    * Add trends in the Curses interface (issue #1077)
 
 Bugs corrected:
 

glances/attribute.py

@@ -126,6 +126,10 @@ class GlancesAttribute(object):
         """
         return self._history[-pos]
 
+    def history_raw(self, nb=0):
+        """Return the history of last nb items (0 for all) In ISO JSON format"""
+        return self._history[-nb:]
+
     def history_json(self, nb=0):
         """Return the history of last nb items (0 for all) In ISO JSON format"""
         return [(i[0].isoformat(), i[1]) for i in self._history[-nb:]]

glances/compat.py

@@ -35,6 +35,7 @@ if PY3:
     from xmlrpc.server import SimpleXMLRPCRequestHandler, SimpleXMLRPCServer
     from urllib.request import urlopen
     from urllib.error import HTTPError, URLError
+    from statistics import mean
 
     input = input
     range = range
@@ -103,6 +104,9 @@ else:
     viewvalues = operator.methodcaller('viewvalues')
     viewitems = operator.methodcaller('viewitems')
 
+    def mean(numbers):
+        return float(sum(numbers)) / max(len(numbers), 1)
+
     def to_ascii(s):
         """Convert the unicode 's' to a ASCII string
         Usefull to remove accent (diacritics)"""

glances/history.py

@@ -49,9 +49,9 @@ class GlancesHistory(object):
         for a in self.stats_history:
             self.stats_history[a].history_reset()
 
-    def get(self):
+    def get(self, nb=0):
         """Get the history as a dict of list"""
-        return {i: self.stats_history[i].history for i in self.stats_history}
+        return {i: self.stats_history[i].history_raw(nb=nb) for i in self.stats_history}
 
     def get_json(self, nb=0):
         """Get the history as a dict of list (with list JSON compliant)"""

glances/plugins/glances_cpu.py

@@ -229,8 +229,16 @@ class Plugin(GlancesPlugin):
         idle_tag = 'user' not in self.stats
 
         # Header
-        msg = '{:8}'.format('CPU')
+        msg = '{}'.format('CPU')
         ret.append(self.curse_add_line(msg, "TITLE"))
+        trend_user = self.get_trend('user')
+        trend_system = self.get_trend('system')
+        if trend_user is None or trend_user is None:
+            trend_cpu = None
+        else:
+            trend_cpu = trend_user + trend_system
+        msg = ' {:4}'.format(self.trend_msg(trend_cpu))
+        ret.append(self.curse_add_line(msg))
         # Total CPU usage
         msg = '{:5.1f}%'.format(self.stats['total'])
         if idle_tag:

glances/plugins/glances_mem.py

@@ -183,8 +183,10 @@ class Plugin(GlancesPlugin):
 
         # Build the string message
         # Header
-        msg = '{:5} '.format('MEM')
+        msg = '{}'.format('MEM')
         ret.append(self.curse_add_line(msg, "TITLE"))
+        msg = ' {:2}'.format(self.trend_msg(self.get_trend('percent')))
+        ret.append(self.curse_add_line(msg))
         # Percent memory usage
         msg = '{:>7.1%}'.format(self.stats['percent'] / 100)
         ret.append(self.curse_add_line(msg))

glances/plugins/glances_memswap.py

@@ -154,8 +154,10 @@ class Plugin(GlancesPlugin):
 
         # Build the string message
         # Header
-        msg = '{:7} '.format('SWAP')
+        msg = '{} '.format('SWAP')
         ret.append(self.curse_add_line(msg, "TITLE"))
+        msg = ' {:2}'.format(self.trend_msg(self.get_trend('percent')))
+        ret.append(self.curse_add_line(msg))
         # Percent memory usage
         msg = '{:>6.1%}'.format(self.stats['percent'] / 100)
         ret.append(self.curse_add_line(msg))

glances/plugins/glances_plugin.py

@@ -27,7 +27,7 @@ import re
 import json
 from operator import itemgetter
 
-from glances.compat import iterkeys, itervalues, listkeys, map
+from glances.compat import iterkeys, itervalues, listkeys, map, mean
 from glances.actions import GlancesActions
 from glances.history import GlancesHistory
 from glances.logger import logger
@@ -156,12 +156,13 @@ class GlancesPlugin(object):
         """Return the items history list."""
         return self.items_history_list
 
-    def get_raw_history(self, item=None):
+    def get_raw_history(self, item=None, nb=0):
         """Return
         - the stats history (dict of list) if item is None
         - the stats history for the given item (list) instead
-        - None if item did not exist in the history"""
-        s = self.stats_history.get()
+        - None if item did not exist in the history
+        Limit to lasts nb items (all if nb=0)"""
+        s = self.stats_history.get(nb=nb)
         if item is None:
             return s
         else:
@@ -215,6 +216,17 @@ class GlancesPlugin(object):
         else:
             return None
 
+    def get_trend(self, item, nb=6):
+        """Get the trend regarding to the last nb values
+        The trend is the diff between the mean of the last nb values
+        and the current one.
+        """
+        raw_history = self.get_raw_history(item=item, nb=nb)
+        if raw_history is None or len(raw_history) < nb:
+            return None
+        last_nb = [v[1] for v in raw_history]
+        return last_nb[-1] - mean(last_nb[:-1])
+
     @property
     def input_method(self):
         """Get the input method."""
@@ -798,6 +810,20 @@ class GlancesPlugin(object):
                     value, decimal=decimal_precision, symbol=symbol)
         return '{!s}'.format(number)
 
+    def trend_msg(self, trend, significant=1):
+        """Return the trend message
+        Do not take into account if trend < significant"""
+        logger.info(trend)
+        ret = '-'
+        if trend is None:
+            ret = ' '
+        elif trend > significant:
+            ret = '/'
+        elif trend < -significant:
+            ret = '\\'
+        logger.info(ret)
+        return ret
+
     def _check_decorator(fct):
         """Check if the plugin is enabled."""
         def wrapper(self, *args, **kw):