# Copyright (C) 2008, 2009 Red Hat, Inc.
# Authors: Phil Knirsch
#
# 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 2
# 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#

import os, copy
import logging, tuned_logging

log = logging.getLogger("tuned.disktuning")

class DiskTuning:

	config_section = "DiskTuning"

	def __init__(self):
		self.devidle = {}
		self.enabled = True
		self.power = ["255", "225", "195", "165", "145", "125", "105", "85", "70", "55", "30", "20"]
		self.spindown = ["0", "250", "230", "210", "190", "170", "150", "130", "110", "90", "70", "60"]
		self.levels = len(self.power)

	def _updateIdle(self, dev, devload):
		idle = self.devidle.setdefault(dev, {})
		idle.setdefault("LEVEL", 0)
		for type in ("READ", "WRITE"):
			if devload[type] == 0.0:
				idle.setdefault(type, 0)
				idle[type] += 1
			else:
				idle.setdefault(type, 0)
				idle[type] = 0

	def init(self, config):
		log.debug("Init")

		self.config = config
		if self.config.has_option(self.config_section, "enabled"):
                        self.enabled = (self.config.get(self.config_section, "enabled") == "True")

		log.info("Module is %s" % ("enabled" if self.enabled else "disabled"))

	def cleanup(self):
		log.debug("Cleanup")

		for dev in self.devidle.keys():
			if self.enabled and self.devidle[dev]["LEVEL"] > 0:
				os.system("hdparm -S0 -B255 /dev/"+dev+" > /dev/null 2>&1")

	def setTuning(self, load):
		if not self.enabled:
			return
		disks = load.setdefault("DISK", {})
		for dev in disks.keys():
			devload = disks[dev]
			self._updateIdle(dev, devload)
			if self.devidle[dev]["LEVEL"] < self.levels-1 and self.devidle[dev]["READ"] >= 6 and self.devidle[dev]["WRITE"] >= 6:
				self.devidle[dev].setdefault("LEVEL", 0)
				self.devidle[dev]["LEVEL"] += 1
				level = self.devidle[dev]["LEVEL"]

				log.debug("Level changed to %d (power %s, spindown %s)" % (level, self.power[level], self.spindown[level]))
				os.system("hdparm -S"+self.power[level]+" -B"+self.spindown[level]+" /dev/"+dev+" > /dev/null 2>&1")
			if self.devidle[dev]["LEVEL"] > 0 and (self.devidle[dev]["READ"] == 0 or self.devidle[dev]["WRITE"] == 0):
				self.devidle[dev].setdefault("LEVEL", 0)
				self.devidle[dev]["LEVEL"] -= 2
				if self.devidle[dev]["LEVEL"] < 0:
					self.devidle[dev]["LEVEL"] = 0
				level = self.devidle[dev]["LEVEL"]

				log.debug("Level changed to %d (power %s, spindown %s)" % (level, self.power[level], self.spindown[level]))
				os.system("hdparm -S"+self.power[level]+" -B"+self.spindown[level]+" /dev/"+dev+" > /dev/null 2>&1")

			log.debug("%s load: read %f, write %f" % (dev, load["DISK"][dev]["READ"], load["DISK"][dev]["WRITE"]))
			log.debug("%s idle: read %d, write %d, level %d" % (dev, self.devidle[dev]["READ"], self.devidle[dev]["WRITE"], self.devidle[dev]["LEVEL"]))

_plugin = DiskTuning()