add random plugin

Signed-off-by: Mattias Andrée <maandree@operamail.com>

4 files changed, 97 insertions, 3 deletions

diff --git a/Makefile b/Makefile
index 1754792..e691341 100644
--- a/Makefile
+++ b/Makefile
@@ -32,13 +32,13 @@ PLUGINS = chase clock cpuinfo cpuonline cpu df discstats ipaddress  \
           kmsg leapsec linereader loadavg lunar mem moc network     \
           pacman snmp snmp6 softirqs solar uname uptime users       \
           vmstat weather xdisplay xkb alsa dentrystate inodestate   \
-          files hdparm tzclock ropty ping inotify
+          files hdparm tzclock ropty ping inotify random
 
 PLUGIN_EXAMPLES = chase clock cpu cpuinfo cpuonline df discstats   \
                   ipaddress kmsg loadavg lunar mem moc network     \
                   pacman uname uptime users xdisplay xkb alsa      \
                   dentrystate inodestate files tzclock ropty ping  \
-                  inotify
+                  inotify random
 
 TRICK_EXAMPLES = localutcclock anytzclock
 
diff --git a/TODO b/TODO
index 78b5287..91b2145 100644
--- a/TODO
+++ b/TODO
@@ -45,7 +45,6 @@ List of plugins to implement:
      /proc/sysvipc
      /proc/locks
      /proc/swaps
-     /proc/sys/kernel/random/
 
 Demo plugins:
 
diff --git a/examples/plugins/random b/examples/plugins/random
new file mode 100644
index 0000000..67b97b3
--- /dev/null
+++ b/examples/plugins/random
@@ -0,0 +1,36 @@
+# -*- python -*-
+
+# A xpybar configuration example testing the features of plugins.random
+
+import time
+import threading
+
+from plugins.random import Random
+from plugins.clock import Clock
+
+
+OUTPUT, HEIGHT, YPOS, TOP = 0, 12, 24, True
+
+
+clock = Clock(sync_to = Clock.SECONDS)
+
+start_ = start
+def start():
+    start_()
+    async(lambda : clock.continuous_sync(lambda : bar.invalidate()))
+
+
+random_ = Random()
+def redraw():
+    data = [('Avail', random_.entropy_avail),
+            ('Size', lambda : random_.poolsize),
+            ('Read', lambda : random_.read_wakeup_threshold),
+            ('Write', lambda : random_.write_wakeup_threshold),
+            ('Reseed', lambda : random_.urandom_min_reseed_secs),
+            ('Boot', lambda : random_.boot_id)]
+    
+    text = ' │ '.join('%s: %s' % (text, str(value())) for (text, value) in data)
+    
+    bar.clear()
+    bar.draw_coloured_text(0, 10, 0, 2, text)
+
diff --git a/src/plugins/random.py b/src/plugins/random.py
new file mode 100644
index 0000000..c942f35
--- /dev/null
+++ b/src/plugins/random.py
@@ -0,0 +1,59 @@
+# -*- python -*-
+'''
+xpybar – xmobar replacement written in python
+Copyright © 2014, 2015  Mattias Andrée (maandree@member.fsf.org)
+
+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/>.
+'''
+
+
+class Random:
+    '''
+    Entropy pool status
+    
+    @variable  poolsize:int                 The size of the entropy pool, see `man 4 random` for more information
+    @variable  read_wakeup_threshold:int    The number of bits of entropy required for waking up processes
+                                            that sleep waiting for entropy from `/dev/random`
+    @variable  write_wakeup_threshold:int   The number of bits of entropy below which we wake up processes
+                                            that do a `select` or `poll` for write access to `/dev/random`
+    @variable  urandom_min_reseed_secs:int  The minimum number of seconds between urandom pool reseeding
+    @variable  boot_id:int                  Random UUID generated when the system is booted
+    '''
+    
+    
+    def __init__(self):
+        '''
+        Constructor
+        '''
+        def read(filename):
+            with open('/proc/sys/kernel/random/' + filename, 'rb') as file:
+                return file.read().decode('utf-8', 'replace').rstrip('\n')
+        
+        self.poolsize                = int(read('poolsize'))
+        self.read_wakeup_threshold   = int(read('read_wakeup_threshold'))
+        self.write_wakeup_threshold  = int(read('write_wakeup_threshold'))
+        self.urandom_min_reseed_secs = int(read('urandom_min_reseed_secs'))
+        self.boot_id                 =     read('boot_id')
+    
+    
+    def entropy_avail(self):
+        '''
+        Get the number of bits available in the entropy pool.
+        Note that `poolsize` is in bytes on Linux<2.6.
+        
+        @return  :int  The number of bits available in the entropy pool
+        '''
+        with open('/proc/sys/kernel/random/entropy_avail', 'rb') as file:
+            return int(file.read().decode('utf-8', 'replace').rstrip('\n'))
+