[gentoo-commits] proj/R_overlay:master commit in: roverlay/db/

[André Erdmann]

commit:     3b92458a280855f69a6aabc8a6c84e4868562444
Author:     André Erdmann <dywi <AT> mailerd <DOT> de>
AuthorDate: Tue Jul 30 16:02:12 2013 +0000
Commit:     André Erdmann <dywi <AT> mailerd <DOT> de>
CommitDate: Tue Jul 30 16:02:12 2013 +0000
URL:        http://git.overlays.gentoo.org/gitweb/?p=proj/R_overlay.git;a=commit;h=3b92458a

roverlay/db: rrdtool.py

---
 roverlay/db/rrdtool.py | 176 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 176 insertions(+)

diff --git a/roverlay/db/rrdtool.py b/roverlay/db/rrdtool.py
new file mode 100644
index 0000000..6d450fe
--- /dev/null
+++ b/roverlay/db/rrdtool.py
@@ -0,0 +1,176 @@
+# R overlay -- stats collection, wrapper for writing rrd databases
+# -*- coding: utf-8 -*-
+# Copyright (C) 2013 André Erdmann <dywi@×××××××.de>
+# Distributed under the terms of the GNU General Public License;
+# either version 2 of the License, or (at your option) any later version.
+
+from __future__ import division
+
+# NOT using rrdtool's python bindings as they're available for python 2 only
+
+import logging
+import os
+import time
+
+import roverlay.tools.runcmd
+from roverlay.tools.runcmd import run_command
+
+import roverlay.util
+
+import roverlay.util.objects
+
+class RRDVariable ( object ):
+
+   DST = frozenset ({ 'GAUGE', 'COUNTER', 'DERIVE', 'ABSOLUTE', })
+
+   def __init__ ( self,
+      name, val_type, val_min=None, val_max=None, heartbeat=None, step=300
+   ):
+      if val_type not in self.DST:
+         raise ValueError ( "invalid DS type: {!r}".format ( val_type ) )
+
+      self.name      = name
+      self.val_type  = val_type
+      self.val_min   = val_min
+      self.val_max   = val_max
+      self.heartbeat = heartbeat or ( 2 * step )
+   # --- end of __init__ (...) ---
+
+   def get_key ( self ):
+      mstr = lambda k: 'U' if k is None else str ( k )
+
+      return "DS:{ds_name}:{DST}:{heartbeat}:{vmin}:{vmax}".format (
+         ds_name=self.name, DST=self.val_type, heartbeat=self.heartbeat,
+         vmin=mstr ( self.val_min ), vmax=mstr ( self.val_max )
+      )
+   # --- end of get_key (...) ---
+
+   __str__ = get_key
+
+# --- end of RRDVariable ---
+
+class RRDArchive ( object ):
+
+   CF_TYPES = frozenset ({ 'AVERAGE', 'MIN', 'MAX', 'LAST', })
+
+   def __init__ ( self, cf, xff, steps, rows ):
+      if cf not in self.CF_TYPES:
+         raise ValueError ( "unknown CF: {!r}".format ( cf ) )
+      elif not isinstance ( xff, float ):
+         raise TypeError ( "xff must be a float." )
+      elif xff < 0.0 or xff >= 1.0:
+         raise ValueError (
+            "xff not in range: 0.0 <= {:f} <= 1.0?".format ( xff )
+         )
+      elif not isinstance ( steps, int ) or steps <= 0:
+         raise ValueError ( "steps must be an integer > 0." )
+
+      elif not isinstance ( rows, int ) or rows <= 0:
+         raise ValueError ( "rows must be an integer > 0." )
+
+      self.cf    = cf
+      self.xff   = float ( xff )
+      self.steps = int ( steps )
+      self.rows  = int ( rows )
+   # --- end of __init__ (...) ---
+
+   def get_key ( self ):
+      return "RRA:{cf}:{xff}:{steps}:{rows}".format (
+         cf=self.cf, xff=self.xff, steps=self.steps, rows=self.rows
+      )
+   # --- end of get_key (...) ---
+
+   __str__ = get_key
+
+   @classmethod
+   def new_day ( cls, cf, xff, step=300 ):
+      # one CDP per hour (24 rows)
+      return cls ( cf, xff, 3600 // step, 24 )
+   # --- end of new_day (...) ---
+
+   @classmethod
+   def new_week ( cls, cf, xff, step=300 ):
+      # one CDP per 6h (28 rows)
+      return cls ( cf, xff, 21600 // step, 42 )
+   # --- end of new_week (...) ---
+
+   @classmethod
+   def new_month ( cls, cf, xff, step=300 ):
+      # one CDP per day (31 rows)
+      return cls ( cf, xff, (24*3600) // step, 31 )
+   # --- end of new_month (...) ---
+
+# --- end of RRDArchive ---
+
+class RRD ( object ):
+   # should be subclassed 'cause _do_create() is not implemented here
+
+   RRDTOOL_CMDV_HEAD = ( 'rrdtool', )
+
+   LOGGER = logging.getLogger ( 'RRD' )
+
+   def __init__ ( self, filepath ):
+      self.filepath       = filepath
+      self._commit_buffer = []
+      self._dbfile_exists = False
+      self.logger         = self.__class__.LOGGER
+      self.INIT_TIME      = self.time_now() - 10
+   # --- end of __init__ (...) ---
+
+   def time_now ( self ):
+      return int ( time.time() )
+   # --- end of time_now (...) ---
+
+   def _call_rrdtool ( self, args, return_success=True ):
+      return run_command (
+         self.RRDTOOL_CMDV_HEAD + args, None, self.logger,
+         return_success=return_success
+      )
+   # --- end of _call_rrdtool (...) ---
+
+   @roverlay.util.objects.abstractmethod
+   def _do_create ( self, filepath ):
+      pass
+   # --- end of _do_create (...) ---
+
+   def create_if_missing ( self ):
+      if self._dbfile_exists or not os.access ( self.filepath, os.F_OK ):
+         return self.create()
+   # --- end of create_if_missing (...) ---
+
+   def create ( self ):
+      roverlay.util.dodir_for_file ( self.filepath )
+      self._do_create ( self.filepath )
+      if os.access ( self.filepath, os.F_OK ):
+         self._dbfile_exists = True
+      else:
+         raise Exception ( "database file does not exist." )
+   # --- end of create (...) ---
+
+   def add ( self, values, timestamp=None ):
+      if timestamp is False:
+         t = 'N'
+      elif timestamp is None:
+         t = str ( self.time_now() )
+      else:
+         t = str ( timestamp )
+
+      self._commit_buffer.append (
+         t + ':' + ':'.join ( str(v) for v in values )
+      )
+   # --- end of add (...) ---
+
+   def clear ( self ):
+      self._commit_buffer = []
+   # --- end of clear (...) ---
+
+   def commit ( self ):
+      if self._commit_buffer:
+         self.create_if_missing()
+         self._call_rrdtool (
+            ( 'update', self.filepath ) + tuple ( self._commit_buffer )
+         )
+         self.clear()
+   # --- end of commit (...) ---
+
+# --- end of RRD ---